Document J6xX52jJ4gY1BkZyMMpJxGGB

til Officers 1938-1939 mend Chairman--]. H. Lee, Liberty Mutual Insurance Co., Rockford, III. icc-Chatrmm--S. T. Dibsdale, The J. G. Brill Co, Philadelphia, ;Pjl 'cretary--*M. C GooDSPEEb,GeheralE!ectricCb.,Erie,Pa. ews Letter Editor--Karl N. Searles, American Car & Foundry Ca, New York; N. Y. ngmeermg Committee Chairman--]. A. Grouse, Southern Lumber Co, Warren, Ark. embership Committee Chairman--Louis Glazes, Dierks Lumber & Coal Ca, Kansas Gty,Mo. . fster Committee Chairman--O. M. Swanson, Joslyn Manufacturing & Supply Con Chi cago, III rogram Committee Chatrmon--O. C Boileau, RCA Manufacturing Co., Inc, Camden, N. J, ublicity Committee Chairman--F. Ai Pollock, Lumbermens Mutual Casualty Co., Chi cago, hl - - o. tfety Instruction Card Committee Chairman--Thomas Sherry, Potlatch Forests, Lie, Lewiston, Idaho. atistics Committee Chairman--Wfm.' D.Jenkins, British Columbia Lumber & Shingle Manufacturers Assm, Vancouver, B. C, Canada. 'embers at Larger? R. C Barr, LumbermensMutual Casualty CoV San Frandsco.Calif. *F. VV. Braun, EmployersMutuals, Wansau,Wis. . R. F. Caldwell, Moore & Merldein, Inc, Shreveport, La. *E. Ross Fabka, Grand-Rapids Safety CouncD, Grand Rapids, Mich. Harry Guilbekt, The PuUipan Co, Chicago, HI . .' PolandJones, The SurtyManufeurturirigCb^ Chicago, I1L 1 )iry J. Kelley/American Seating Co, Grand Rapids, Mich.;_ alter S. Paine, Aetna Casualty & Surety Co, Hartford, Cohn. *J. A. Purdy, Michigan Mutual LjabilityGa, Detroit, Mich. *G. E. Sanford, General Electric Co, Schenectady.N. Y. *H. E. Seely, The Brurawkk-Balke-Collender Ca, Chicago, 111. *Fut General Chairman r.i m m , * Officers 1939-1940 i eneral Chairman-*]. C. Wilson, Lumbermens Mutual Casualty Co., Chicago, 111. tcretary--*M: C Goodspeed, General Electric Co, Erie, Pa. 'ews Letter Editor--Charles H. Jones, Bituminous Casualty Corp., Chicago, III ngmeermg Committee Chairman--James. G. Aldrich, Berst-Forster-Dixfield Co., Platts burgh, N, Y. c` . ifalih Committee Chairman-*-A. D. Hubbard, Employers Mutualr,' Wausau, Wis. fembership Committee Chairman--Lam* Glazkr,. Dierks Lumber & Coai Co., Kansas City, Mo. 'otter Committee Chairman--O. Mi Swanson, Joslyn Manufacturing & Supply Co., Chicago, III. 'rogram Committee Chairman--O. G Boileau, RCA Manufacturing Co., Inc., Camden, N*'J. 693 i - PLAINTIFFS PLAINTIFF'S EXHIBIT EXHIBIT \fc/i/~oa5rnn Is 0/45 V. 3 694 28th National Safety Congress Publicity Committee Chatrtnan--F. ^ Pouxkk,'. U Casualty Oo., Chi cago, 111. '- Safety Instruction Card Committee Chairman--Thouas Sherry, Potlatch Forests, Inc., Lewiston, Idaho. . O Statistics Committee Chairman--Will D.- Jenkins, British Columbia Lumber & Shingle Manufacturers Assn., Vancouver, B.C, Canada. Trade Association Cooperation Committee Ckairman~D. J. Murray, The HuberManu- facturing Co., Marion, Ohio. Members at Large-- .. ,v . R. C. Barr, 'Lumbermens Mutual Casualty Gx, San'Francisco, Calif. F. W. Brauk, Employers Mutuals, Wausau, Wis. R. F. Caldwell, Moore & Merklein, Inc, Shreveport, La. EL Ross Farra, Grand Rapids Safety Council, Gnind Rapids; Mich-; Harry Guilbert, The Pullman Ox, Chicago, III Roland Jones, The Surty Manufacturing Co., Chicago, 111. Harry J. Kelley, American Seating Gx, Grand Rapids, Midi. - *J. H. Lee, Liberty Mutual Insurance Co, Rockford, I1L WalterS- Paine, Aetna Casualty & Surety Co^Hartford. Conn. J. A. Purdy, Michigan Mutual Liability Co., Detroit, Mich. . *G. E. Sanford, General Electric Gx, Schenectady, N. Y.' *H. E. Seely, The Brunswick-Balke-Collender Co, Chicago,- III. Past General Chairman : : MONDAY AFTERNOON SESSION October 16,1939 The first session of the Wood Products Section was called to order by General Chairman J. H. Lee, Safety Engineer, Lib* erty Mutual Insurance Company, Rockford, 11L, who presided-. In his opening'remarks. Chairman Lee sketched some of the activi ties of the Section during' the peud year, paid' tribute to the Sectional Committees for their work, and then introduced die first speaker... Health Hazards in theWoodWorking Industry ByRRSAYBBS Senior Surgeon, Drvirion of Industrial Hygiene* WarionaIJiutTtate of Health, U.S.PubBc Healdi Serric^ WasMngtosi.p.C. . In 1935 there were 579,012. workers In the United States employed in industries in which wood in some form is die princi pal material. Of - this number 283,309 were employed in the basic-industries and 133,772 in the furniture and related in dustries. The remainder %ere in woodreworking . industries, wooden-container industries, and other allied industries.. Only limited data as to absenteeism due to all illness or.to occupational diseases are available. However, in a survey of 1,487,224 workers employed in 16 indus try groups in 16_ states the data given in the accompanying tablesbowing exposures were obtained.for the.lumber*and furniture industry. - "o The table shows that dusts and the chemicals involved In finishing: and preserying .wopd constitute the major .expo sure which may. Cause; .illness or un toward symptoms. Dust ' -.^ Many processes in the wood industry (sawing, planing,-- boring, drilling, belt- Perceafof Fnrititt * ` v' Mater Humber of/ 1. .Organic 2.. Silica di 3. Dermati 4. Petroleu 5. Lacquer 6. Organic 7. Other i & Silicate 9.' Carbon . 10. Paints.a sanding, ren . gtfve rise to ' Smith,' in relationship disease, stat to conditiot trade of wc increased ri Although to whether i ' "for an inert among won agreement enough com irritation oi The possibi that tills tyj of then tube foiy tract Is no condt dust is the dence of tt tory infecti more extern thuttban ha tobewarrai The occtt inhalation o mentioned; carried' oat oratory itth intheUppe symptoms i twitic ;Tht they came maple kgs The dust ; p htnghs tdo ticaleR ah the-condith Wood Products Section 695 . , 4 -4 ?er -joC Workersin the Lumber and effectand foreign body-reaction, combined mittuelndustries Exposedto with a 'delayed effect resembling protein Specified Materials sensitization jii its clinical -and. certain .Materials ;. . WorkersExposed . imniuhologic effects. The authors recom' mended preventive measures which in imber ofworkers surveyed 93,375 clude the; removal of affected patients .^)rg9Lmd dost^. 51.8 from the .environment of. the spores as. Siliei dost;....:.......` 57 soon as they are detect^, or exhaust ven- . Dermatitis producers ......... 57. . tilation of the sdws during the-working . Petroleum products ----- -- 5.0 . process. . Lacquer and variush ...I....... ; 37' . Organic solvents i..........>** 3.6 Poisonous . Woods.. ,The fact that con Other metals. ....................... U.. 32 tact with certain wopds and their dusts . Silicate dost .......... ___ ..; 27; may produce an irritationof the skin, mu Carbon monoxide .........'. *' 27 cous membranes or symptoms of general . Paints, and I Je.n.'am' els,..;....O..... i, 2.1 poisoning is well recognized. The major ity of-'cases of dermatitis and tbxic sym- ading, removal and utilization, of waste) . toms frmnj woodoccnr inc those whose re rise-to wood dust.' k work brings them in contact',with the-dust , *5 .C . * c . .. and- sawdust derived -from these woods. Smith; in reviewing the literature on the However, Eruptions haye occurred" from tationtiup of wood dust, to respiratory other Wes of contact sfich as proximity >ease, statesjhat on the whole exposure .jo tife tree alone or while handling the conditions of work -incidental toithe wood iffany way. ' ide of woodworking carries with, it an leased risk from .respiratory disease.' Woods of tropical origin are the more Although there may be disagreement as whether woodjdust?per se'is responsible r an increased incidence of tuberculosis aong woodworkers . there is>.' general reemeht that organic . dust infugh otr * ^concentrations may produce sorae fti k of the upper respiratory, tract, te possibility has also-been suggested at this type of-dust,may act as acarrier ther, tuberclebadlltts into theJ respira- common offenders.. However,, the wood of numerous, trees native to temperate climates has also been found to produce .^irritation. Among them arer birch, Cali fornia sequoia,;chestnut, hemlock spruce, Norway, spruce, Japanese Tagayasan, cocobolo, Brazilian., walnut, blackwood, satinwood, sabicu, mahogany, teakwood, . ebony, boxwood, yew .wood, red, cedar, j&k, and beech. ry tract In view of. the fact thatjhere Few figures'are available as to the in no conclusive evidence that .pure^ wood cidence of- dermatitis from contact with ist is the cause of the increased' inci- woods.' Schwartz found dermatitis re nce^'of tuberculosis and'/otfaer. respira- sulting'from the dust of-Braalian'walnut ry infections,-^inong spud workers -a in 11 of. lOO workers in agcabinet-malring are extensive .mvestigatkm. of thp ques-,, plant.- He cofnnmmcatea with other firms utthan has yet been made would appear,' using the urood; jnd 9 of;10; reported in be warranted. ,,5*; stances of eruptions apparently attribu- The occurrencf of asthma due to the table to the Brazilian walnut, the dumber taxation of fungus spores should also be of workers`affected in the'different fac- entibnedi Towey^ Sweany anid Huron' tortes Varying from one or two to a ma rried out a clinical, roentgen and labr jority. One firm reported that it had story 'study on * series' of 35 patients discontinuedjhe use of the wood-because the Upper Peninsula of Michigan* The.,. mptoms were -acute and. typically; aath-. oPthe large number of workers affected. It is obvious,, however;`from the'relative itic. - These men were `working where ^frequency of reports dealing' with such ey came into' contact "irith dust froift woods^ as satinwood. that seositivity oc tple logs cut for inoie tham a year. ' curs frequently withaome, while the ie dusfJ proved /to be' the spores of a g*identified)'as''Coniostfrum1 >r Infrequent or .single mention ofl^thoc woods . mdica^s rthSltv reactions to them sueE. and E.Tlntne' authors* opinion," e-condith>nwaB due to a local toxic The precise origin of the toxic effect of ** ' r77'v. \ 696 28th National Safety Congress woods has not been accurately deter and dermatitis. Although .perforation of mined. Some authorities believe that the the nasaLseptum has been reported, it is tone agents are free unsaturated adds; infreque'nts---*'. s''*" ' others, that they are resinous oils and ^Prolonged work with stains containing alkaloids. Other -types of diemicals are methyl alcohol mayjeause optic neuritis. responsible in some cases. "Polishers' itch", an eczematous condition The toxidty frequently varies with the habitat and in many varieties of wood, from one tree to another. Thus, it is re ported that cocobolo wood from Panama can produce dermatitis, while that from of the hands and arms,, is common among wood polishers, the causative agent being either petroleum, shellac. dissolved . in wood alcohol, or in alcohol denatured with pyridine bases. Nicaragua appears to be harmless. _ The The use of the spray gun and dip tank variation in toxidty from one tree to for the application of paints and lacquers another is particularly marked in the case has largely replaced the hand brush in of satinwood. ' industry in painting operations. The The majority of woods are most toxic when freshly cut but a few become in creasingly harmful as-they age. Thus' cases of dermatitis have been reported in persons who had sat on brandies of adoption of these methods has resulted in a change in working conditions with re sultant hazards of two types: those relat ing. to toxicity and . those relating to flammability. the rengas which had been cut and dried' The substitution-of harmless pigments for months. The use of this wood for the for toxic pigments has rendered many manufacture of furniture has practically paints much less poisonous. Turpentine ceased because of the production of symp and benzol have been displaced by other toms by furniture which has been in use solvents in many paints during the past for years. i' 15 years. Local or general symptoms of poison A few years ago lacquers displaced ing usually appear within a: few hours,' paints in many finishing operations.' The days, or weeks following contact with an ordinary lacquer contains several basic irritant, wood. However, cases .have been ingredients such as nitroedhdose, solvents reported in which workers after years of and diluents, gums or resins, softeners or immunity to a toxic wood have become plasticisers, and pigments. The volatile susceptible to irritation by the material. - ingredients constitute about 75 percent by In the case of some woods, tolerance may weight of an average lacquer. be established, but as a rule, sensitivity, once established is persistent In general, the eruptions present the usual picture of dermatitis venenata although a -number of variations occur. Perspiration and seborrhea apparently increase the noxious action of practically all woods. The af fection is considered by most observers to be allergic. The evaporation of the volatile fraction constitutes the major occupational disease hazard in the use of lacquer, although the vehicle, pigment and resinous compounds cannot be entirely eliminated from con sideration as possible offenders inasmuch as the toxic properties-of many of-'them are unknown. Among the pigmetits which may be toxic are those yellows, greens and Patch tests with moist sawdust are oranges which contain lead chromate, the usually sufficient to establish the diag aniline derivatives and possibly those con nosis in cases of suspected wood der taining cadmium, antimony and barium. matitis. - Over 100 solvents are used in the lac Paints, Lacquers, Varnishes. The paints, lacquers, varnishes and stains employed in the finishing of furni ture and other wooden articles constitute a second major health hazard. quer industry alone. (15)... Some of the more- important solvents are the esters, such as. the acetic add esters of methyl, ethyl, propyl, butyl and amyl alcohol, and the ethers which include the alkyl ethers of ethylene gljrcol. The effect of alcohol, Chromates and bichromates which-are used for staining and in polishing wooden articles favor the development of ulcers on the hands and feet, of conjunctivitis,. ether and massive doses (in excess of 1,000 p.p.m.) of the ester solvents ismainly narcotic in action. Some of them are-also irritating to the skin and mucous mem branes. T1 determine sure and |tion for m The imp hydrocarix xylol, napl ethyl, prop cydohexar greater tk 100 p.pm. serious dai gans of i Labour Ol 100 p.p.m thresbhold trations of tory were parativdy sound. B: of 100. p.p age to the perimental are probat usage. - Themos of volatile; and conse< the eoncen phere to h though son tone actio produce n; in suffidei practice of discriminat their hand: absorption serious sy: cracking o the remova ' skin of the openings tl established . Tbevola constitute 1 as the m nitrocellulo dement Persons i wood for weather-pn and resista vesicular ai 6"'oT "7**'' ... Wood Products Section 697 f * , irane$. There Is need of investigation to ;et; jine the effects of.,prolonged expo- ure and the maxunum. safe concentra- ion for many of these compounds. the chemicals employed. Eczema of the skin and catarrhal conditions of the mu cous membranes of the head are fairly common. The important diluenfs (thinners) are the" tydrocarbons which include benzol, toluol, ylol, naphtha, and the alcohols (methyl, thyl, propyl, butyl and amyl alcohols and ydohexanol). Air concentrations of peater than 50*75 p.p.m. of benzol and Creosote which is used for the preserva tion of wood to be used for outdoor con struction purposes is a primary skin irritant and may also result in the develop ment % of occupational coal tar photosen sitivity. 00 p.pjn. of toluol or xylol may produce ; Although the creosoting process has erious damage to the blood-forming or- largely replaced the use of chromated zinc ans of the' body. The International chloride in the preservation of wood to be .abour Office regards a concentration of used outdoors,' the latter is still used for 00 p.p.m. of . methyl alcohol as the wood intended for- indoor construction. hreshhold of toxicity. However, concen- McCord and Kilker examined 17 workers rations of 200 p.p.m. in a New York fac- employed in a wood preserving indust oiy were observed to give rise to com- and found that of the four types offskin aratively slight intoxication in the per* lesions presented, three were well knqwn- onneL Butyl alcohol in concentrations as.incident to work in tar. Zinc chlonder^ f 100. p.p.m.' is reported to cause dam- burns-were the fourth type of'lesion and ge to tiie blood, liver and kidneys of ex* were present in all patients, occurring on crimental animals. The other alcohols .the fingers, hands, forearms, and occasion re probably not very toxic in ordinary ally, on the legs and thighs.' sage. . In determining the causes of the lesions The most important route of absorption it was found that the strength of tiie' zinc f volatile substance is, through the Itmgs chloride "solution in the. .treatment fluids nd consequently it is~ essential .to keep was too dilute to produce skin lesions. lie concentration of vapors in the atmos- However, during the -period when the ties here to^be breathed at a minimum. Al- were left in the open auyjfollowjng their some of the vapors have but little removal from the treatment cylinder, u )ction, any volatile material may evaporation of the water-from the zinc roOuce narcosis or asphyxia if present chloride solution occurred so that the ties 1 sufficiently high concentrations. The when handled in loading were sometimes ractice of some lacquer workers of in* covered with treating fluid , in which the iscriminately using solvents to cleanse zinc chloride approximated saturation. iieir hands should be discouraged, since Additional factors to be considered, with bsorption through the skin may produce respect to zinc chloride burns are: (1) erious systemic damage and since, the antecedent injury to the skin appears to be racking of the skin which results from necessary; (2) after the initial lesion, re* ie removal of the fats and oils from the ' peatedexposure to the zinc chloride solu kin of the hands and forearms provides tion and irritation from the tar fraction of penings through which infection'may be itablished. the treating solution are factors in the severity and progress of the leslion. Experimental studies have shown that The volatile materials present in lacquer approximately one percent mixtures of institute the principal fire hazard as well phenyldichlorarsine in medium or heavy i the major health hazard although hrocellulbse adds another inflammable lenient petroleum distillates are efficient wood preservatives'. Although -these mixtures have hot yet received commercial use it Wood Preservatives should be kept in mind that tests have shown that marked . initial vesiculation Persons engaged in the impregnation of may occur in certain, persons exposed to ood for .the - purpose of rendering .it the action of phenyldichlorarsine. eather-proof, water-proof, fire-repellent, Pentachlorphenol and tetrachlorphenol ad resistant- to fungi may suffer from are also used as wood-preservatives. In ssicular and other skin eruptions;due to addition to being primary skin irritants 698 28th National Safety Congress they may also be absorbed through the* clothing, gloves, goggles and aprons, as skin in sufficient amounts to cause sys well as protective salves,- ointments or temic poisoning. other compounds fo delay or diminish the Other chemicals which are used for im pregnating wood include. dinitrophenol, aniline, potassium bichromate, fluorine irritant action. General rules for hygiene and good housekeeping should also be ob served. compounds and mercuric compounds. Ac Safety education and the proper main cording to the literature, each of these tenance of equipment and safety devices chemicals possesses toxic properties when are the important factors. absorbed in sufficient, quantity into the Medical Control. Medical control, through body. Ultimately, only careful medical examination in conjunction with the study of types and amounts of exposure will es tablish their importance as health hazards. preemployment and periodic physical exam ination, is one of the most important factors in the prevention of industrial injuries and illness. ,, Engineering Control. The basic prin The preemployment examination serves ciple in dealing with a dust, gas or. fume to determine the employee's physical and hazard is control at the point of origin, mental fitness for work. The purpose of thus preventing dissemination into the at such examinations is not to eliminate or mosphere. Sometimes a process can be exclude an employee, but rather to direct enclosed or isolated completely in a sealed t his placement in work for which he is room or compartment, but frequently the physically suited. The practice of preem exhaust ventilation method is preferable. ployment examinations should also be ex Water may be used to prevent the dis tended tq include executives and officials. persal of dust and under' certain condi tions it may be advisable to combine the use of water with exhaust ventilation. Proper design, installation and mainte nance of any mechanical device is essential if protection is to be adequate. The purpose of periodic examinations is to secure and maintain physical fitness. Defects and disabilities which were not observed at the time of employment may be discovered, on reexamination. In. such cases, an occupational adjustment should Individual types of respiratory protec be made to provide continued employment tive devices such as masks or respirators and remove the. risk of permanent injury. should be used only where exposure is in Reexamination of employees also serves termittent or brief, or where some unusual as a check on the efficacy of the engineer condition makes a more adequate control ing control methods already instituted, or method impracticable/ as a measure -of the need for new pro In the case of materials producing ex tective devices. The frequency of exami ternal irritation, auxiliary protective meas nations should be determined by the medi ures may include the use of protective cal director unless specified by law.. WEDNESDAY AFTERNOON SESSION October 18,1939 Use and Abuse of Circular Saws and Their Relation to Safety By ALBERT L. UHL Sales Engineer, Henry Disston & Sons, Inc., Tacony, Philadelphia, Pa. Circular wood-cutting saws are divided into four classes, namely: cross-cut, rip, combination, and grooving. Each of these saws has its own use in the wrood-woridng industry. Circular cross-cut saws are manufactured hi several patterns of teeth and on many spacings of teeth. Each -one has certain peculiar work to do, but in all classes the teeth should be bevd filed to best save the wood fibre . filed straigi backs, aitht in the cutti on the bad This howev of the saw 2 In novdi - cutting teet and the rak through--m raker or de : is left by t! that this' tj best result should be 1 sections of hardwood slower that raker shoul sections of I . soft wood, A inch shoi In additio tion tooth & bination in g various styl tice is. to 1 pitched abot of a rip saw saw. The' f: ripping, cro! must be fik factorily wl we recomro -be less tha cross cuttinj for ripping. Circular s made fiat-gi must be set rule, will u face. The clearance at is mostly ,i* cutting. Th the teeth' in spring type It is obvi crease with capableof positive or < machinery i manufacture Wood Products Section 699 ,ror* fibres. Circular rip saws are usually shops manufacturing wood substitutes and lei might through on both the faces and other products. acks, although in some cases, particularly The dangers existing In .the lumber planing i the cutting of hardwoods, a slight bevel, and industrial plant mills in connection with n the backs of the teeth is recommended^, ~ circular saws are due chiefly to-- 'his however,' is only done where the teeth f the saw are spring set. 1. Saws being out of round. 2. Saws being dull. In novelty-tooth combination saws, the 3. Setting teeth improperly. utting teeth in each section are bevel filed 4. Alteration in shape of teeth. nd the rakers or cleaners are filed straight 5. Carelessness in sharpening saws. trough--no bevel. The function of the 6. Failure to maintain proper speed. Run iker or cleaner Is to remove the core which ning-saws at a speed faster than that left by the scoring teeth. Hence, in order ' for which they are tensioned. taf this' type of saw be filed to give die 7. Saws not properly aligned. est results, the cleaner .or .raker tooth - 8. Center hole in saw not correct size for tould be 1/64 to "A inch shorter than the mandrel. tctions of the cutting teeth. For cutting . 9. Saw not fitting collars properly. ardwood where the feed is necessarily 10. Saw mandrels not level, end play in owner than,--when cutting soft wood, the mandrel, uneven collars, mandrel bear iker should he 1/64, inch shorter than:{he ings work, and failure to keep bearings ictions of the cutting teeth. But for cutting well oiled. >ft wood, weirecommend that the raker be . 11. Insufficient gullet space. i inch'shorter than the "sections for cutting.. Saw Out of Round In addition to the raker pattern combina- bn tooth saw there are3other types of corn- This condition develops from lack of care nation in general use. These aire made with when filing the; saw to- resharpen it. A saw trious styles of teeth. The general prac- should balance: on the mandrel, but if, in ce is. to have the face-line of the teeth filing, more metal is removed from one por itched about h^lf-way.between the face-line tion of the saw than from another, a light f a rip saw and the. face-line of a cross-cut and a heavy side develop. The teeth in one lw pe fact that these saws are used for section of the: saw are nearer the exact ppu ^,, cross cutting and mitering, the teeth center than others. The heavy or long side ust be filed so that they will work satis- performs all of the work, but does so in ictorily when making these cuts. Hence, a "hammering" style, which may cause sev e recommend that the bevel on the teeth eral lands of accidents; the throwing back i less than ordinarily, recommended for of stock bring cut or a destruction of'the oss cutting but more than we recommend saw through breakage, either of which .is a >r ripping. hazard. . Circular saws in the majority of cases are ade flat-ground. In which case, the teeth ust be set for clearance. Such saws, as a de, will not produce a smoothly, cut surcc. The set teeth, however, place die earance at the .rim of the blade where it -mostly .needed in order to produce fast itting. There-are .two methods of setting e teeth in circular rip saws:, one is the ring type set, the other, the swage , set. To rprevent accidents through this cause, care must al^ys be taken when "fitting," which means setting and sharpening circular saws, to,see that they are made perfectly round; ie., by "jointing" them. Jointing is accomplished by placing a piece ofemeryistone on die saw table. Then press it lightly, bnt firmly, against the points of thei'ieeth,| while the saw is revolving, until all teeth show evidence of contact with the stone. (Extreme care should be used in do- Relation to Safety . ing this to avoid accidents.) It is obvious that all safety factors in ease with the devclopment of equipment, pable of faster speeds arid feeds, mid isitive or self-feed features. This type..of achinery is usually installed in the reanufacturing or woodworking shop, and in Saws sharpened wjth..aut6(naHc,machines will keep saws roqnif^L ' DulT.Saws IV1" * ^ Regardless of the particular kind of saw, afl must be kept sharp to avoid accidents. 700 28th National Safety Congress Anything which contributes to the destruc An improperly swaged saw may have tion of a saw is a factor inclining toward teeth spread on one side more than on the causing accidents.. A saw must be sharpened other, or the point of the tooth may be before it becomes so dull that it drags and turned down instead of straight If the pulls. set is uneven, it will;cause the'saw to lead Dullness of saws is closely related to items three and five in our fist of causes of acci dents ; namely, improper setting of teeth, and carelessness in sharpening saws. If a saw is improperly fitted (wrongly set, even though correctly sharpened, or wrongly sharpened even though correctly set), it may heat on the rim, and ex pand, thereby causing rim cracks which may result in total destruction of the saws.' It may also cause the saw to spring over the collar, or to spring and bend out of shape, resulting in "lost tension." When this occurs, the saw should be- rehammered,* retensioned and refitted immediate!}'.. ` in or out of the cut, which may result in the bending to one side, coming in contact with parts of the machinery or.saw bench. If the points of the teeth turn down, this destroys the back clearance, causing rim heat and destruction of tension, with its associ ated dangers. To eliminate all hazards created by this cause,. a saw can .be properly swaged by using a hand swage, spreading the metal with the convexed ride of the swage and straightening it -with the square ride of the swage. The proper angle to hold the swage is determined by the tongue or center piece, which should rest oh-the top of tire tooth. When ..a roller or die swage is used, it is Setting Teeth necessary to see that the spreading dies are Before discussing the proper methods to follow in order to eliminate causes for accidents developing out of these conditions, it will be necessary to designate the various types of circular saws used in the lumber mill. These are-- not worn. .If dies are always kept hr good condition,* the swage set will be made cor rectly. After using a roller or die swage, it is 'necessary, in order to complete a correct swage set, to shape the spread metal with a swage shaper. Edger saws..........................Swage set teeth Bolter saws.......................Swage set teeth. Lath saws'........................... Swage set teeth Trimmer saw's......... ......... Spring set teeth Slasher saws .............. Spring set teeth After this operation has been completed, with a hand swage, the saws should be side . dressed, with. a side file; which brings the swage equal on both sides, eliminating the causes contributing to dangers. Log Deck saws.........Spring set teeth The same hazards of binding, leading and There is a decided differoice in the work which each type of saw performs, but the difference that we wish to consider now is the condition of the teeth when the}' are swaged properly or improperly, and when they are spring set--properly or improperly. heating, are created by an improperly spring set saw.. The teeth ordinarily., are sprung with a spring saw set or "knocked over" with a hammer as the tooth lies on an anvil. Here-again, as in swaging, if the teeth are spnmg or set more, on one .ride than on the other, the saw will lead* in one It is necessary to set the teeth of a saw direction. in order to furnish clearance for the blade while in the cut Swaging means spreading the metal at the cutting edge of the tooth. .Teeth which are spring set. in the correct way should not be set more than one-quarter the depth down the tooth. Uneven setting of' the teeth places greater strain on some Spring setting means bending or spring teeth than on others, and may cause them ing of the teeth alternately rig$t and left to break. When a saw is swage set properly, each tooth will chisel or cut an equal amount of material from the "path" of the cut- Im properly swaged, it will spring, dodge or bind in the cut. There is danger of its throwing back the material being cut, and Too much set.not only places unnecessary strain on tire rim of the saw, resulting in cracked gullets or broken, teeth, but -also makes the saw vibrate in the cut, which may cause a deflection of the stock. running out of fh'e cut, both of which may If there is not enough set, the saw wifi destroy the blade. bind or. jam in the cot This beats the rim and gu total destnu . Teeth in i highest effit the multipli cutting angl been scientii - 'Forexam the angle oi to a fine dx of the saw, cutting to b front !ine.< mately oqe' "center of ti "^e. center I tioa of the fc For cross will run ale center of ti ting the line line or sUg Tins "cat mines the The line > signed to g dent strong gullet for'tl cat It is obvi desired, but rushed toget Thepropc determined requirement! Grinding line of the gullet line; formed by * curve. Cross-cut' on tire faces Rip saws with no bev on the back. All of the part of the safety. To i conditions o dents. fli^ngiiig alter its cn Wood Products Section 701 m^d gullet cracks, develop, or possible creates' or develops friction or strains de t& kruction of thesaw. velops hazards. Shape of Teeth Changing of the bade line either. will weaken the tooth or reduce the back clear Teethin saws have been designed for the ance. Weakening of the tooth may cause ` ghest efficiency and maximum safety in breakage. Reducing toe back clearance will le multiplicity of catting problems. The cause friction. ltting angles, top relitfi gnlkt line, all have Changing toe gullet line will either weaken sen saentificklly determined and laid out the tooth, if it is deepened, or may result For example^ the hook of a tooth; which is Oin a sharp corner or nick in die gullets. This te angle of the face of die tooth in relation is the cause for most dracks and breakage. a line drawn directly through the center i the saw, depends entirely on the type of. , ,> Sharpening Saws ltting to be done. For general ripping the;' not line.of the tooth will run approxiately one-half the distance between;' the It is during toe reconditioning process that the original shape of toe tooth is altered. After a saw has been "spring set" the in inter of the saw and the rim, in back of side corner of the tooth may be high. te.center in relation to'the naming direcw of the tooth. It is by correct fifing that tins is dimi-. nated. Bevefing'Of the face and back of For cross-cutting; the book of the tooth teeth which have been spring set will bring ill run along the line directly through the this high inside comer down. inter of the saw, or for special cross-cotng the line may ran in front of the central le or slightly back of .the central line. Extremely wide bevels on the face of teeth in cron-cut saws produce severe lateral (cross) strains and this may cause gullet This "cutting-angle" of the tooth deter- cracks, and teeth break out ines the front line of the style or ^design. Cross-cut saw teeth are designed to shear . The line of die bade of die tooth is de- the fibre. A long sharp, bevd is necessary. gned to give proper bade, clearance, suffi- ent strength to the tootb/'and a proper lUr' ror`the storage of dost when in the a. ) ; It is obvious that maximum strength is sired, but ample guild room must be fur- Rip saw teeth are designed to chisel in the cut. A straight across filing is necessary to retain the chisel cutting edge. It is during sharpening that sharp corners or nicks are created which will result in cracking or breaking the saw. shed together with proper bade dearance. After toe saw has been properly jointed The proper lines for saw teeth have been and set filing below toe blunt point left by itenmned on the basis of die cutting the jointing will shorten the tooth, thereby qnirements. preventing it from doing its full share'of Grinding or filing of the front.and back cutting, throwing undue strain on the other ic of toe tooth forms the gullet This teeth; such strains are causes of.failures in diet line; regardless of rise, is never ' saws. irmed by a sharp angle. It is diways on a irve. ' Proper Speed Cross-cut'saws have the teeth beveled both l the face and on the hack. Rip saws are filed square adoss the fa<x ith no bevel, but.may have a slight bevel i the bade. All of these factors must he considered as rt of the "style of tooth" necessary; for fety. To alter any one or all is'to create ndidons contributory to failure and acdnts. " All saws are. tensioned to operate at defi nite speeds. Unless ordered to operate at a certain speed, most saws are tensioned to run laOOO feet run travel per minute. Tensioning is a process by which toe metal or body of the saw is adjusted when . idle to compensate for strains developed when rotating. Centrifugal force causes an expansion of the rim of. a circular saw. The faster toe speed, toe greater the expan sion. The standard speed being 10,000. feet Changing top front fine of toe.tooth will rim travel per minute; if toe mandrel speed ter its cutting behavior.-, Anything that and diameter of the saw result in a rim feet 702 28th National Safety Congress travel greater than 10,000 feet, then it is necessary to contract the rim by forcing the metal in toward the center of the saw, to a degree capable of compensating for the addi tional speed of travel and added, rim ex pansion. Saws Improperly Aligned This applies particularly to mill rip saws. The amount of lead required for circular saws should be the least possible that will keep the saw7 in the cut and prevent it beat ing at the center. If the lead into the cut is too much, the saw will heat on the rim; if out of the cut too much, the saw will heat at the center.' Heat will.cause expansion and the ex pansion of any portion of the satf Will dis tort the tension and may cause costly damage . Ordinarily of an inch lead in 20 feet will be correct, although operating condi tions and conditions of equipment will at times alter this and set iip new requirements. Center Hole in Saw It is obvious that center holes smaller than mandrels will not go on, so we are confined in this consideration to holes which are larger than mandrel shafts. ' When a saw is operated in this condition, the same hazards develop as those for a saw which is "out of. round" The sawhangs on the mandrel unbalanced, and will hammer through the cut, with the attending dangers. - Saws Not Fitting Collars Mandrels not level, end play in mandrel, uneven .collars, mandrel bearings worn, and failure to keep bearings well oiled--all these defects are so closely related that they are mentioned as associated causes of acci dents. If the collars are allowed to be loose or if the face of the collars becomes worn irregularly, or if a foreign substance is permitted to come between the collar and saw, the blade is distorted by conforming to the collars or by bending over the foreign substance. Failure to tighten the collar against the saw7 is extremely dangerous. An attempt to operate a circular saw with a collar of too small diameter may result in the saw bending over the collar, due to lack of support A saw mandrel having worn boxes not level or with end play will cause the saw to wobble, run unevenly, chatter and heat in the cut, causing cracks and breakage, which always are dangerous to the operator. The same conditions exist in the manu facturing or woodworking shops and have the same relation to safety with circular saws, as those in the lumber mill. In addi tion, woodworking shops utilize other types of saws which in some respects present dif ferent problems of safety. The groover saw; dado head, smooth cut ting combination saws, and high-speed ma- . chinery with positive feeds as previously mentioned have added to the necessities for "perfect conditions" of saws in order to avoid accidents. Grooving Saws , These ` usually are buried in the cut and special care must be exercised in the feeding of. the material into the saw, in order to avoid its bring thrown back at the operator. It is vital that these saws be kept in per fect condition. They must always have suf ficient set to furnish clearance; must be kept sharp and in absolute roundness. The fact that they are buried in the cut demands spe cial attention to these conditions. Dado Heads . . This is an. assembly of saws and cutters, used to perform the same function as' a groover, hut suitable to make a variety of grooves ;of different widths, by the addition or removal of inride cutters as the.need demands. Special attention must be given to having a dado head in "perfect joint" (which means absolute roundness), snug fitting on mandrel, properly assembled, .always sharp, and securely tightened between collars. ' Usually dado 'heads are "buried in the cut," a severe operating condition. It is important that,the inside cutters be set for clearance.. If swage set, they must be uniform. If spring set, care must be exercised so that the. inside, corners will overlap and not leave a' sliver in the cut, which will cause friction, burning of the head, and probable jamming in the cut .Cuts are made with the grain, across the grain, and d teeth, both < cutters, are so, as with tooth as o; altered. Shi teeth must hi "1 These saw the sides of a smooth cc As their i cut and nut tion" saws. The tooth rial purpose which are n and a cleanei The cuttir the cut; leat moved by th the cut The scori teeth furnisl addition to t of the blade. \Wien "fi operate free! Woe I started i have held a past twenty passed thro into the new because safe operation of The Cali Company w ways lent it suggestion 1 tion of bett tions: pure! tidns in shoj to make en A most e The Pullma of employee devising ne Wood Products Section 703 aip ^nd diagonally across the grain. The etll )th of the outside cutters and inside itters, are designed to perform this .-work, , as with other saws, the shape of the oth as originally made should not be tered. Sharp nicks in the gullets of any zth must be eliminated. Combination Saws These saws have the clearance ground in e sides of the blade, in order to produce smooth cut. They require "no set" As their name indicates, they rip, crosst and outre. Hence the term "combinain" saws. The tooth has been designed for that sped purpose and consists of sections of teeth, rich are made up of .special cutting teeth d a cleaner. The cutting teeth score the way through e cut, leaving a center core which is reoved by the cleaner tooth which follows in e cut The scoring performed by the cutting ith furnishes clearance for the cleaner in dition to the clearance ground in the sides the blade. When "fitted" properly, the saw will crate freely and without burning. "Proper Fitting" The teeth should be so filed that the cleaner will be slightly lower than the cutting teeth, ft the cleaner teeth are per mitted to remain longer than the cutting, teeth, then the cutting teeth never function. The cleaner tooth forces its way through the' cut, generating friction with its resultant hazards. . . Correct fit of center hole, the correct tension, saws out of round, dull saws, care lessness in sharpening, failure to maintain speed and operating at excessive speeds, are as important factors in these, saws as in the circular saws operated in the lumber mills. Maintaining shape and size of gullets in saws operating on self-feed rip saw machine is very important. An important consideration, although for eign to die topic of "condition of saws and. their relation to safety," is the proper selection of a saw. For example-- Combination saws will not rip in a satis factory manner on a self-feed, high-speed rip machine. An incorrect choice may de velop hazards just as destructive as improper condition of a saw. ) Wood Shapers By GEORGE H. GIBSON Wood Mill Foreman, Calumet Shops, The Pullman Company, Chicago I started in the Wood Mill in 1895, and ve held a supervisory position for the. st twenty yews. So yon see, I have ssed through the old CARELESS era to the new SAFETY era. I mention this cause safety is a vital part .of the proper >eration of tools and shapers. The Calumet Shop of The Pullman >mpany where I am employed has altys lent its wholehearted support to any ggestion that would aid in the protnom of better and safer working condins: purchasing guards, malting alterans in shop set-np, and devising systems make employees "safety conscious." A most encouraging polity, in effect in te Pullman Company is the rewarding employees for improving old guards,or vising new ones.' I have been the re cipient of several such bonuses. Equally as important is the effort exerted by our management to keep working conditions SAFE.. Pullman employees are educated to the fact that Safety is an integral part of their work, and in our wood machine department, we are now past the nineyear mark without a lost time accident. Before a job is started, I constantly en deavor to make certain that each worker has the proper tools and set-up. Should 1 detect anything amiss, I call the man's at tention to it and assist him in correcting it Occasionally the .operators have better ideas than I do, and I never hesitate to adopt them. I am of the opinion that the leader, foreman, or whoever is responsible for overseeing the job should understand that he is the "key" safety man, respon- .. .\\ 704 28th National Safety Congress sibte for the safe operation of the work under his supervision. ' In selecting a man to operate a machine, it is wise to choose one who is not afraid of the machine but who has a wholesome respect for its dangers. See that the area surrounding the machine is kept clear so that the operator has plenty of room to swing his work. Provide a piece of old carpet for the worker to stand on in order to minimize slipping hazards. Make sure that the machine Is in perfect working order. If the machine is belt driven, counter shaft pulleys and belts must be properly guarded. It might be well to write to the National Safety Council for their pamphlet No. 7 on "Safe Practices on Belts and Belt. Guards." Knives must be properly balanced, making sure the cutting edge has the proper cutting bevel and that they are sharp. It is important that the bevels on the edge of the cutters upon which the collars rest are the same because many times the knife null throw itself when the bevel does not correspond with its mate. After the cutters have been set, it. is your duty to see that the operator has the correct starting approach to the point of operation and that the proper safeguards are in place.. Of course the type of guard is determined by the operation to be per formed. and worlcmi ardous cot practices as matter of cc tine 'work, by a central occurrence that hazardc ing practices - In giving and training ward the' c whether, the laborer or<s! would be t! company wc an expert in Safety or* a safety exet Safety in the Use of Edge Tools department members of By RAY A. FINCH the chief bt ..."'TS, ' U. S. Fidelity ft Guaranty Co* Baltimore^ Maryland chairman' S< posed of suf In addition to. Safe Practice pamphlets, issued by the National Safety Council, in formation appearing from time to time in the National Safety News and other safety publications, literature prepared and dis tributed by manufacturers of planer and company which was and is self-insured. Our - insurance department handled all matters under their jurisdiction. If acci dents occurred, our claims department went into action, but immediately insur ance coverage was extended. The work of with the plai manager pre number of ings, so org; cations, as workmen. -. e jointer equipment, and information pre the safety department, of which I was a The Exec pared by manufacturers of guards , and part. , was to extend such safety service complete jur protective equipment, this subject was and to plan and put into operation organ and safety pi ably treated during , the twentieth annual ized safety efforts which would protect had authority Safety Congress - before the Advanced the risk. referred tori Safety Engineering on Friday; October Briefly, our safety, plans included in 16, 1931. Again, this subject was discussed spections of'the physical property, tools, at the .Safety Congress held in-Washing and equipment; observations of working ton, D. C., in 1932. The Congress Transac methods and practices; conferences with tions show- that here in Atlantic City dur the management .to determine that proper ing the Safety Congress held in 1936, the attention was given to the selection, train subject was again discussed by two ca ing, and supervision of workmen, to de pable speakers before this section,-and last termine or to provide ..for proper safety year at the Congress held'in Chicago on and working rules, to provide for the October 12,. all tire newest and latest de- . proper distribution of safety posters; and velopments in the care, adjustment, and safety literature and-to agree upon and safe operation of this equipment was dis make effective a safety organization de cussed by members of this section. signed to meet the particular needs of the visory: meeti Meetings of medium for > pasty.safety, which ocean ing remedial agement op] matters of th asgivenby t . important co: Supervisor visors the < study aetidei As I have just mentioned, these talks operating company. mine accidet and discussions will be found in your cop . Following our inspections of the phys ies of the printed Transactions of the ical property and equipment, naturally the purpose tide upon res > Safety Congresses, and you can find them in the proceedings^jf this progress when they have- been printed and distributed. During the first eleven. years .of my safety engineering training, I was with a such recommendations were immediately offered as were neededto correct obvious hazards, but our inspections-were carried on and our recommendations submitted in such manner as to cause supervisors j be adopted i These meeti) tided opport supervisory t of rise actide pertisors and Wood Products Section 705 d; jkmen to detect and confect haz- finitely understand that safe and efficient ddw_ conditions or Unsafe working . operation was. one of their major respon- actices as a day^by day proportion,, as a sibilities. But rather than damp that re nter of course, in carrying mitheir rou- sponsibility on the shoulders of the. fore- le work, rather than await' inspection men or supervisors and then.withdraw, as a central office safety engineer, or the is so'often done, then return at a later date cnrrence of an accident to. point out and point ouf to supervisors that they had it hazardous conditions or unsafe work- . failed in their responsibility, we went ^practices had developed. ' further'throngh the employee group safe- (n giving attention to proper selection *7 meetings and assisted the foremen in 4 training of employees, we pointedto- gahimg^the co-operation of workmen, ird tiie objective', that on every job, This was accomplished in the employee ether the individual was assigned, as . group safety meetings by creating a prpp- tbrer or^ skilled mechanic, the workmen er understanding .first of safety funda- mid be thofongbly trained. That the mentals. Employees were made to under- npany would in fect have on every job stand that: their suggestions . and expert in his particular field. r recommendations intended to eliminate Safety organizations provided for, first, unsafe conditions or Unsafe practices were tafety executive committee composed'of wanted by the management. They were (Mirtment heads,.: local managers, and made to understand that accidents were ; snbers of the general management, with 'analyzed'.primarily, for the purpose of de i chief operating executive* acting as termining causes and remedial measures urman/Second, safety conimittees com- to .prevent thefryn$prrenc rather than sed of supervisors and foremen usually to. place blame uponlhe injured employee th the phut superintendent or the lOc^ti orothers mvolvf&mjthe accident. By the' stager presiding; and, third, a sufficient manner in whidr-the meetings were con oaber of employee group safety min- ducted, employees over" a perked: of time 8, so organized by departments' or lb-', were 'jffi3bd to analyze jobs before they ions, as to include all employees or wore parted to give assurance that proper rlcmen. protective equipment would be on hand, Tff Jjcecutive Safety Committee bad opiate jurisdiction over the safety plans and : that accident producing hazards would be anticipated and guarded against. 1 safety progrsun of the operations .and . By.iqaking the meetings interesting and" I authority to act. upon any. suggestions erred to the committeeeitherbysuper- by ' develi^myt *ke feeling or spirit of friendly corppbmtibn, employees , were iwy: meetings or employee meetings, caused to vofoijtarilycxraply with safety stings ..of this committee provided'a rales even without constant supervision; dium for executives to formulate com- also, employees were caused to co-operate lysafety policies, to analyze accidents with and partiripate in the safety activities ich occurred for the purpose; of adopt- of the company, not because of the cost of remedial measures, and gave theman- accidents should they occur, but as a'mat raent opportunity to give to safety ter'of good'operation. The mystery was Iters of tiie company the same attention taken out oTacddent prevention work and pvenby theboard of directors to other employeesa&hsed to realize that accidents mrtant company affairs, are usually the result of mistakes, that iupervisor safety meetings gave supers ws the opportunity to analyze, and iy accidents which occurred to deter-, doing virbrfc safely was largely' a matter of doing the job the way they knew the job shottld be done. te accidenat causes, not primarily for H Iinn .ssnhoorrtt,, thne aim otf thne employees'' purpose of placing blames but to de^^ety program was through proper selec- t upon remedial measures whichsbould adopted to prevent their recurrence, tse meetings of supervisors also prosd opportunity for studying improved ervisory methods'and all other phases the accident prevention problem. Su- boa W fearing to place an expert on every job and then in every manner pos sible to help that expert remember to do his'job the way he knew it should be done. .... That method of conducting safety ac tivities has been .successful since 1914. risors and foremen were made to def- In April of 1935, I joined one. of the 706 28th National Safety Congress Government agencies as safety engineer. ities today are sufficiently important to The operation to which I was assigned . tax the ability of capable .and practical was heavy dam construction. With very men with vision' and imagination-men little .change the safety plaits effected in capable of leading workmen, capable of .that operation were identical with those' causing men to put forth their best ef which I have just described. Although it forts, capable of causing workmen to has been contended that such ' accident understand that preventing accidents is prevention plans will not work on con merely a matter of doing~work properly. struction jobs, because of the large labor turnover, and even though in the opera tions to which I refer -we were confronted with , the problems presented by an abun dance of green labor, in the face.of all that, the plans were successful. Perhaps it wilt be sufficient to point out that as a result of our efforts, we were awarded the- safety trophy given by the National Safety Council for our type oper ations at the National Safety Congress in 1936. - . Definitely, inspections do have a place in the.safety program, bnt.it is my belief that they should be so conducted that supervisors or workmen will be led or so" directed that they will detect the unsafe conditions or the unsafe working practice and will immediately makeor cause to' be made,-the necessary corrections as a part-, of their day by day work. Only in that manner can effective -accident prevention be accomplished. Also, we must make proper use of safety posters and other I know you agree that just as the suc safety literature to give better .assurance cessful industrial supervisor today must be that all types of individuals will be a leader rather than a driver, the success reached.,, y ful safety engineer must be capable of cre ating safe attitudes, and capable of maintaining safety understanding and in terest! Even today "the woods are full" of individuals who call themselves safetyengineers but who are in reality merely .Safety meetings with supervisors must be held in order that, by proper exchange and discussion of experiences and meth ods, all supervisors will be kept abreast with latest developments. Proper atten safety "inspectors," and who apparently tion should be given to physical examina believe and give the impression that theirs tions, proper attention must be- given.to is the responsibility for preventing all ac selection -and. placement of individuals, cidents, Men who create the impression workmen must he properly trained in that only through their personal inspec order that inexperienced men .will be tion of property or equipment can haz properly instructed or to give assurance ardous conditions or unsafe working that experienced men do understand their practices be detected and corrected. Who work- Cooperation, a spirit of friendli-' expect to bend down all the upturned ness, job interest, and job pride must be nails, to erect all needed handrails or bar created and' maintained, .through group riers, and who usurp the. authority dele safety meetings. Through employee group gated to supervisors by giving orders .to safety meetings, the safety engineer must workmen or take die worker's place by give the supervisor or foreman the bene personally making adjustments of equip fit of his safety engineering experience by ment. helping the supervisor and foreman to gain the cooperation of employees under We sometimes wonder just what proce that supervisor's supervision. The man- dure would be followed if those individu- - agement must sincerely , attempt to pro als were `given a crew of men and instruct vide a'-safe place in which to work. Safety ed to build a fence line. It is not'unreason- guards, barriers, and protective equipment able to assume that they might attempt to must be furnished. dig alt the post holes themselves while the members of the crew stood around, with ' However, I believe you will agree that the wire, the posts, and other material* un even after safety equipment and . protec til he had completed the excavation. tive equipment, guards, and appliances Naturally, some other member of the crew have been provided, that is, even after the likely would take over the job of directing job has been wrapped up, men who do not the work. Surely, in the light of recent possess - the correct safety attitude will developments, accident prevention activ fail to use protective equipment, will crawl in beftint guards, a hand, me standing In this speeded i molder k tions cam Try as molders, venations tors whid are matte portance. After s know abc good, wori One do realize th equally d lessr lot c under whi The im cutter hea sized by t` operation rotation it (assuming eter). For exj force exer The load knife weif cutter hea creases as At 3 At 6 At Z In othei spindle sp< load on th of the law as the sqi merely .ini Neverthi are desirat speed, the and tearinjf Wood Products Section 707 in behind barriers, or will fail to- use g| fa, and will be hurt. On ' the other ha..u, men who..have the correct understanding of the purposes of accident pre- vention, who have the proper safety atti* tude and understanding can work even around hazardous conditions without being injured. Wood Stickers, Molders and Matchers By ROBERT WILLIAMS Safety Engineer,. ThomasviUe Chair Co., Thomasville, N. C. In this era of high-speed machinery and, . But'all the foregoing- statements are speeded up production, the importance, of merely, in the nature, of a background for molder knife and. cutter head specifica the more important fact that these knife tions cannot be emphasized too much. forces, are transmitted to the heads and Try as I may to discuss other phases of everything pertaining to knives and cutter molders, I cannot ignore the many con head* must be made accordingly. versations with molder users and opera-. In the. following paragraphs I shall tors which indicate that feeds mi speeds mention some of the fundamentals in con are matters of 'primary interest and im nection with high frequency molder opera portance. tion. After all, what everybody, wants to 1. All types .of cotter heads should be know about a molder is:-- "How much made of . properly treated alloy steel, of goodwork will it do in a given time?" such formulae that- -they have reasonably One doesn't have' to be an expert to realize that the answer to this one is equally difficult,- unless one has an. end less* lot of information about' .conditions under which a molder is to operate. - importance of. molder knife and ctk ) head, specifications has been empha sized by the-use.of high frequency mblder operation because the centrifugal forces of rotation increase, as the square of the speed (assuming a constant cutter head diam hard surfaces to maintain dean edges and tensile strength to prevent distortion, bat drawn to a point to prevent brittle texture of steeL 2. Square heads should . be supplied with knife bolts, of similar characteristics. Maximum tensile strength should be re duced to a point which induded toughness so that there, will be reasonable and gradual elongation before ultimate break ing load is reached. eter). 3. Tipped. high speed steel inlays on For example, consider the centrifugal carbon backed knives are dangerous, and Force exerted on a knife at various speeds, solid high speed sted knives should be rhe load or "pull" on * a J$x3jx4 inch used. knife weighing one pound, attached^to a However, none of these fundamentals is rutter head with a 6# cutting circle in- of. much use. without reasonable care in ceases as follows: At 3600 R.F.M. the poll is 976 At KtfR.P.M. the pull is 2711 operation' and supervision. Some of the important points are: * .1. A well balanced knife setup is the . At 7200 R.P.M. the pull is 3904' first essential. This calls for better bal In other words, when1 you double the ancing scales than are commonly pro spindle speed you multiply the centrifugal : vided. oad on the cutter knife by four, because -.2.-More cleanliness is-'required of all >f the taw that "centrifugal force increases parts pertaining to. cutter heads than is is the square of the* speed" -- and not commonly practiced. nerely in direct proportion to .the speed: Smoothly and accurately ground cutter Nevertheless,' the' higher knife speeds , head and surfaces, assist in holding the xe desirable because the higher the knife knives in place) bat this advantage is lost peed, the cleaner the cat--4ess roughing if the surfaces.are not. carefully cleaned. ;ud tearing. ** Similarly, internal bore of heads, all sur- 708 28th National Safety Congress faces of colletts and spindles are accurately planer head mentioned above, there was ground, partly to. help hold against slip serious consideration of running the risk page, and partly for 'balance,- and both of having it repaired in a local welding requirements are lost if all parts of these job shop..-. surfaces are not properly cleaned at all 6. The use of narrow knives , on square times. heads held with a single bolt--especially Insistence on maximum accuracy of bal if the cut js more or less to one side of ance and cleanliness contribute to develop the knife like a bevel cut, instead of ing other essential operating precautions. straight in--should be discouraged. Such 3. Management' must insist that knife,. bolts, nuts, and screws be tightened with the standard wrenches supplied for these knife setups tend to slip, and should be' steadied with an adjacent non-cutting knife blank. nuts and screws, to prevent pulling of 7. Replacing an overload relay with a threads and distortion of heads. The use "jumper" to .prevent tripping of over of pipes and other wrench handle exten loaded machine motors ought to be a "just sions must be prohibited. cause" for discharging any man. Management has to teach machine men Knives seldom fly out of machine heads that the science of metallurgy has not yet like a bullet out of gun. Such, accidents succeeded in developing a $6 inch diam generally begin with a slight sluffing. or eter bolt which cannot be stretched, or slipping of tiie knife with resultant miss- whose thread cannot be distorted, when machining, and a motor overload, so that subjected to sufficient weight at the end accidents are frequently avoided by the of a two or three foot lever. Damaged automatic tripping of relays. ' threads, and distorted heads are' natu 8. However, all machine men should be rally dangerous. taught, to duck to the floor and reach for I recently saw a 24 inch round slotted the "stop" push-button whenever a ma head of a planermatcher with a split run chine "doesn't sound right" before they ning from the bottom of one slot into the investigate the reason for the unusual bore. It require^ a pipe extension on the sound. ' wrench handle to LOOSEN the H inch set screws holding the knives, but the set screws could not be removed com pletely from the head because their ends had been '`mushroomed" by, excessive pressure. No wonder the head had cracked! 9. Finger, ends are frequently clipped by front side heads of molder spindles be cause operators attempt to remove dusthood before spindle has come to .a stand still. It sometimes takes four to five min utes for vertical ball `bearing spindles to come to complete rest after power is dis 4. Not only is it management's respon connected. Operators should, therefore, sibility to guard against such abuses, but. be taught to always use the mechanical these orders must be supplemented with spindle brakes or .stop each head with its frequent inspections. No matter how hard individual reversible drum control -- if their surfaces, threads of nuts and screws - machines are so equipped except in emer will wear, and worn bolts, nuts, and set gencies, or when quitting at the end of.a screws must be replaced from time to time. day. 5. Similarly with old cutter heads. 10. Operators must be taught to shut You'd be surprisedhow frequently man down their molders when making any' agement plans to use old heads (made of other than operating adjustments. ordinary machine steel and originally We have a report of an operator "drop purchased for slow speed belt driven ping his wrench when reaching to make a molders) with the idea that it is good , blow pipe turnbudde adjustment over top business to "save" a $500 or $600 invest head while it was revolving,-and another ment, when considering the purchase of a of an operator's jacket being caught by $5,000 or $6,000 electric molder for high front side head while reaching to make frequency operation. similar adjustments or repairs. Here is another example along this line: .11. Special- precaution must be insti When the management learned what it tuted to "guard against accidents resulting would cost to replace the 24 inch round from the impression or assumption that a molder ! operator chined a per day. Althoi we are . molder a tor ASS" left the i dition.- ;.12. Th slotted. 1 5/32 incl fourth ai of equal' than a f Moreove . themselv hood tbs cases th into exhi damage. Incidei and. reqt Thin 1 caps on i in round C Acddci industry, i though t education mg injuri : Throng authority mechanic succeeded regulatiot would n every da exposed! : Unfort broken oi chines, g< ous mens plants tha Mecltar strictly a W... o od Pro/.sd* ucts Section 709 ir~*^er setup has-been completed by an manner as, thin knives are generally used 4 )tor of the preceding shift when ma for surfacing with round heads. chines are operated more than one shift Summarizing all these details, we be- per day. =-, .. lieve that^nearly all molder accidents de Although we have no authentic records, velop from carelessness.-..Without further we are tinder the impression that more explanation, this broad statement would molder accident* occur because ope opera seem to jbe an indictment of the machine tor ASSUMES that another operator has i men, but * individual carelessness can be left the machine in proper operating con corrected under proper supervision, and in dition. - c. the final analysis, it is management's fault 12. Thin knives are safer,, than thick slotted. knives because a standard...type 5/32 inch thin knife weighs less than one-- ` for not dictating more operating rules, and for not being more watchful to prevent violation of those rules. fourth as much -as a Ji inch slotted knife - If woodworking machines are kept in of equal'length. Therefore, they exert less proper condition.: by experienced work than a fourth as much centrifugal force. men, the .number of machine injuries will Moreover, they, are more likely to shatter ' be greatly reduced.. If the cutting tool is . themselves against a chip-breaker or dust in, good condition, first class work can be hood than the thick knives, ;and in such cases they frequently have, disappeared into exhaust systems without doing much' damage. Incidentally, thin knives also cost less perforined more rapidly, with less consumption of ppwer and" with far greater safety to the operator. Dull and improp erly set tools are .the direct cause of many of the accidents mistakenly attributed to careless' operation or lack of proper guards. - and. require much less grinding time. Frequent and thorough inspection of all Thin knives may be held under knife- machines, should be made to insure that caps on square heads or they may be used the bearings are' not loose or dry and that in round heads for detail work in the same the belts are in- good order and under , proper tension. . .. c Safety Chips By J;C. WILSON Vice-President, Lumbermens Mutual Casualty Co., Chicago Accidents in the lumber and woodworking industry- continue to be a serious problrfn al though mechanical safeguards and safety education have done' modi toward prevent ing injuries in this dangerous' occupation. ; Through the cooperation of all State authorities having regulatory power over mechanical guarding, safety engineers have succeeded in securing codes .and rales and regulations which, 'if .vigorously enforced, would require, satisfactory guarding for every dangerous . machine--every saw and exposedmoving p* art ' Unfortunately,Jaws are ignored, rules are broken or not enforced, jand saws and ma chined, gears and belts remain thosame seri ous menace to the workers' in hundreds-.of plants that they ,Wt;re 25years ago. Mechanical skfegu&rdihg, teven though strictly enforced, is nofctgbugh to stop acci dents in any industry. Why? Beause we still have "the human element" to contend with. I still am firm in my belief that the best safety device -known is a careful work man. The investigation of an accident of any kind seems to start with the assumption that someone was careless; however, the study of thousands of accidents in the woodworking industry has convinced us that a large per centage of injured workmen are not neces sarily careless. Even, though the employee is injured on-.a properly' guarded saw or ma chine,, in many cases there areother factors Involved beside pure carelessness. Fatigue is a word we hear in all our discus sions on accident prevention and apparently fatigue covers a multitude of errors and en ters as a big factor into a large per cent of injuries. Nervous -strain results from many 710 28th National Safety Congress causes other than physical impairment Poor Were responsible or inexperience Or maybe eyesight carries its share of responsibility as old man "fatigue" enters the picture. Care does mental worry and . we believe that lessness certainly was a factor. worry causes more fatigue and more acci dents than any other one cause. ' "Falling Objects" caused . 61; "Falls, of Persons" 49; and "Steppingvon or Striking What can a safety engineer do about Objects" 57. Too many of these instances worry on the part of a machine hand? Very were, aged employees who fell-from eleva few woodworking plants .have a sufficient tions to -which they should never have been number of employees to require theservices permitted to dinib. of a so-called personnel man whose duties would include a continuous knowledge of the employees and the conditions surrounding their home lives. Generally speaking though, worry and mental disturbances and their cor rection are beyond the. ability of even the Any safety engineer would argue that this group shows lack of supervision, poor housekeeping and in many cases, pure care lessness. All should lend themselves to proper safety education. first-class personnel man. Therefore, these Permit me to rite just a few claims which accident causes, bang too much for others will illustrate my previous statement that the especially trained, have also proved to be too fundamentals of safety in woodworking are much for die safety engineer. However, he selection of workmen, education in the use will continue to work toward his goal of of tools and machines, safeguarding all loss prevention through the selection and points of operation--gears, saws and bdts, education or training of workers, safeguard and constant supervision. ing of machines and constant supervision.. Obviously, all men are not temperamen Let us consider a representative list which tally fitted to work high speed, dangerous analyzes by cause 1000 actual accidents re machines and many are not physically fitted ported to our company by various wood for such work: A ample, physical examina working plants. tion will determine the applicant's condition . These are grouped under seven major and enable the employer to place him on the causes with "Handling of Objects" the larg type of work he 'can safdy perform. est with 327 reports or almost one-third of Education or employee training is costly ) the total.. You will note that 148 of these are of course but it is necessary and very much splinter cases. Many of them, I regret, to worthwhile. Guarding must .be mandatory, say, were neglected with serious results as apparently, required by laws strictly en- infection rapidly follows a high percentage . forced. Lastly, but certainly not least, comes of such injuries when tht workman ignores - constant supervision. or refuses proper first aid. Down in Indiana, an aged employee had "Machinery" is next with 283, and al operated a completely guarded and ex though no breakdown is used to contrast hausted trim saw.1 One day the .dust collec guarded with unguarded 1 assume that at tor choked up and without stopping the saw, least 30 per cent of those machines were this man. removedthe krwer-guard, readied' properly' guarded and the guard being used. in to dear out the choke and lost Ms right This group also covers our most expensive compensation cases for many machine'acci .hand. Where was the foreman? - dents result in permanent loss through am In a Chicago planing mill,' one of the putation or loss of use, and some have workmen decided the tool grinder was not proved fatal. ' running fast enough, so,he changed pulleys The third class under "Particles in Eye" certain!)' could be eliminated to a large de gree by the employer strictly' enforcing: the use of properly fitted goggles by all em ployees grinding tools, while suitable exhaust on the..jack shaft and so speeded'up the emery wheel. that it burst and killed him. A section' cut off a truss rod supporting the roof with the result it collapsed and-injured four others. Where was his foreman? systems will remove at least 75 per cent of Every claim man and safety, engineer the hazard- of sawdust blown into workers' knows the.sad results from-changing saws eyes. There are 128 losses in this group.. and leaving the guard'off--then using a dull Under "Hand Tools" are 87 reports and unguarded rip saw just to saw off one piece we wonder why so many. Perhaps dull tools . --result a Iddt back--perhaps -fatal - Splinter workman, not use pa ing, refus. I recall n vividly, til ago. ..The splinter a back, ente first and < anyone, h and for 1 splinter, ot poultices, too late. . It hard! working p we find a< other, and cause of tl Slippery but certaii machines, serious los correct tba Many o falls are ; short stqid saws. Om bled while have been As you Practice. 1 tional Saf agree tiiat working r preventing for .this-s press, and ctl's Chicaj . It is the the prinap machines t . (a)Tho . (b) Con (c) Suit - chin (d) Ade guai (e) Pro] (f) Goo. (g) Pro] (h) Use WoodPtoductsSection ^ "It ^"'Unters seem to-hold no horrordor the Thoroughly Trained .Workers w jmv handling lumber. -He simply will not use pads or gloves and generally,speak ing, refuses, either first aid or medical care* I recall my most distressing splinter chum vividly, though it happened about 2S years ago. The workman was . ripping when a splinter as,large as a pencil was kicked Injuries sometimes occur to men who are put to work,on jobs with which they are not familiar; If is die* duty of the' foreman to be sure that every man he assigns to a cer tain. job knows the safe methods to be em ployed on that job.' back, entering his right hand between the first and ^second fingers. Without notifying anyone, he ran out of the shop to his home and for four days attempted to draw-the splinter out of die hand with home-made poultices. We finally found him. but it, was too late . Injuries often occur when, men from one department-.attempt to do jobs on a machine in .another department Such men sometimes do work for.;themselves after hours or do not wait for the regular operator to do the .work required. They often .. work without guards or with improperly adjusted ones. . It hardly seems possible that, any wood- It should be a strictly enforced rule that wo'rldng plant would have a poor ladder hut a mas from one department is not to nse a we find as many hr this industry as in any machine in another unless he is given, special other, and we have many* bad accidents be permission to do so. cause of their nse. j Slippery, floors `are dangerous anywhere Correctly Conditioned Tools but certainly should not be tolerated around . The condition .of the tools used in the machines, yet they continue to cause many machines has .a much rnore important rela serious losses. A little glue and sawdust will tion to the number and severity of injuries correct that condition. ..than most persons realize. No matter how Many of those accidents reported under., falls are a direct result of. stumbling over short stock, edgings; blocks and scrap from saws. One man lost a hand when he stnmbled white passing a band saw.' Many others bar ^een injured in the same maimer. well a. machine may be guarded, if the tools in the machine are not suitable for the work, thie operator is potr-afforded nunrimnm pro tection.. A tool that is not in proper condi tion requires greater power to drive it, it does not cat cleanly, and it requires greater -effort to push" the material through the Ar you are all familiar with the Safe machine, thereby increasing the danger of Practice.Pamphlets published by the- Na the operator being injured by slipping and tional Safety Council, I am sure you will falling or in some other manner. It is im agree that the following outline on wood portant that all tools used in the machines be working machine accidents and means of examined at regular intervals by someone preventing them may be cited as standard competent to judge their condition and that. for this` industry. These are just off the all faults found be corrected immediately. press, and may. be scoured from the Cotm- cil's Chicago headquarters, . - Suitable Machinery . It is the opinion of some authorities that.. The machines should be' suitable for the the principal means of preventing injuries on wdrk to be done. A suitable machine prop machines used in wood furniture plants are: erly installed snakes if possible to provide (a) Thoroughly trained workers. . (b) Correctly conditioned machine fools. adequate safeguards and decreases the cost ^of maldng the product A poorly main tained machine is not only a potential source (c) Suitable and properly maintained ma of injury-but it, is: also aq important factor chines. ^ in decreased output Loose borings, poor (d) Adequate .and. properly maintained guards. (ie) Proper flooring about the machines. lubrication, useof worn or defective parts are too important , to be overlooked or neglected.* `(f) Good lighting. (g) Properly conditioned stock. _ . The inspection, and repair of machines should be done only by. qualified persons. Usually the millwright or a similarly quali (h) Use of suitable dothing, fied person performs this-work. When it is 712 28th National Safety Congress necessary to make repairs to a machine dr remove or replace cutting tools,- tile belt shifter or electric switch should be locked in tiie "ofP'position. Otherwise the machine may be started accidentally or too soon and cause injury to the man at work on that machine. Safeguards .All gears, spoke-type wheels and other dangerous revolving; oscillating or recipro cating parts of machines, including the tools should be enclosed as completely as possible with guards of substantial construction. AH machines equipped, with automatic feeding derices which are.likdy to catch the operator's arms or clothing, should .be safe guarded by means of safety switches which will shot off the power and operate auto matic braking devices when light pressure is applied to die guards that are placed over the tool arbors or spindles. All machines, the tools of which remain in motion due to kinetic energy for some time after the power has failed or been shut off,. should be equipped with automatically operated brakingdevices. It is a good policy when purchasing new machinery to include a clause in the pur chase specifications that the maker is to supply all safeguards required by local,- stated or other, authorities having jurisdiction. By so doing, uniform and satisfactory safe guards can usually be obtained at less cost to the machine purchaser than if he at tempted to have.them made himSelf. Flooring In places where the mats are subjected to excessive .wear or are likely- to be run over by trucks, metal plate with an.abrasive . grit embedded -in' the wearing surface isprobablythe .- most satisfactory material to use. (See Safe Practices Pamphlet No. 11, "Floors and Flooring" and Industrial Data Sheet D-Gen. 1, "Slippery Floors.") Good Lighting jj Proper lighting is of vital importance. There is a wide bdief among men experi enced in accident prevention work tint 25 per dent-of all avoidable accidents are due.to improper lighting. It is- important that proper attention he. given-..to tiie maintenance of' all lighting equipment,, t en cleaning and- adjustment of reflectors. Dust accumulating on the lamp bulbs and reflectors quickly cuts down the intensity of the light Tests show that where lighting equipment' is not kept dean there may be loss, of 25 per cent or more in the efficiency of the` lights, Makeshift or im- - . properly adjusted reflectors spoil the effi ciency. of any carefully' worked out lighting system. Washing of windows, keeping material off of window rills, and keeping stock asjray from in front of windows wJU aid greatly in admitting sufficient light in the daytime. When daylight is not snffideht,. artificial light of the proper intensity should be pro vided. Modi information of value on proper . shop lighting will be found in the National Code of Lighting for Factories, Mills and Other Work . Places and in Safe Practices Pamphlet No^.22;"Industrial Shop Lighting." Floors should be kept in good condition, When wood stock is not in proper con with a smooth surface, to prevent tripping, dition it.sometimes warps against the saw and free from accumulation of waste ma - because of .strains in the lumber, or loose terial, small sticks, blocks, shavings and saw knots and slivers may be jarred ^.against dust. the saw by tiie- vibration' of the machine.. The standing space at each machine should be covered with anti-slip material to pre vent tiie operator from slipping and possibly falling against moving machinery or losing hold of stock, being fed through tiie ma chines. Mats, if used, should be cemented or To prevent injury under such conditions it is particularly necessary that the operator, pay strict attention to his work,, that the machine and its tods be in proper working order,-and that the necessary machine safe guards be provided and used. otherwise secured to the floor, and should be renewed wben badly worn or torn. Rob ber mats are probably most commonly used,., Clothing and Eye Protection * Men working about wood furniture plant Some Council members advise that a coat of machinery should wear dose , fitting gar thick paint or glue sprinkled oyer with sand, ments. Torn or ragged-dothing is danger while wet and allowed to dry gives good ous. The ragged edges of coats and jumpers results. often catch in the machinery and cause injury to and fingt Frayed, to frequent]? bands .or 1 the' rapid (See also "Protectiv Men oj severe ey slivers, an ing knives operators to the wearer. Loose or flowmg ties' attached to ..the- machine, table will prevent ail )mger rings "are/ equally ^dangerous. such injuries; (See also -Safe Practices Ff.jed, tom, and ragged. Movies or mittens Pamphlet No. 14, "Goggles," and Health frequently catch in die work and result in Practices Pamphlet No. 6, "Industrial Eye hands .or fingers beingdrawn against orinto the' rapidly revolving ports "of mariimcs. (See also Safe Practices Pamphlet No. 16, "Protective Clothing.") Men operating machines sometimes^suffer severe eye injorks becanse of the' dost, slivers, arid drips thrown off by the revolv Hazards.") s The final conclusions. of this study remain -.the same as oujg^jf'''' We" must! Wemust |>roperly train them. We must gttard the machines. . ing knives.. Suitable gogghritom by the .We must keep our tools sharp. operators of in'some instances1 chip screens We must exact constant supervision. ADJOURNMENT ) % 0' Acme Pr< Gas if American . Scfaoo American Mann: American Fire I American Head Banach A Safety Bear Mai Vehic BendixF Autoi Brown SI Mens Stewart! Safer R- H. Bn Safet; Biirroogl First Carbianl] FoiHe H. Childi Indus TheClev Side Coffinfl Coffin Colombo Alloy H. S. Co' Respi Craddod Indus Davis Ei First C. H. Do Head DogasE Fire;