Document xjY5e9xZn4B342g1Ewy561pYg

FILE NAME: Allied Signal Bendix (ASB) DATE: 1965 May 18 DOC#: ASB205 DOCUMENT DESCRIPTION: US Patent - Brake Drum and Lining United States Patent Office 3,184,001 P atented M ay 18, 1965 1 3,184,001 BRAKE DRUM AND LINING Earl W. Reinsrfc, Dayton, and Gear P. Bayne*, Kettering, Ohio, assignor* to Genera] Motors Corporation, De troit, Mich., a corporation of Delaware Filed Ang. 16. 1962, Scr. No. 217,426 5 Claims. (CL 188--71) This m ention relates to a Kuque transmitting and/or energy absorbing deuce and is specifically directed to brakes, clutches and the like. More particularly, the invention is directed to the combination, of a sintered ferrous brake lining or facing ucJ in conjunction with a brake member including a bracking surface formed iron; steel substantially free front ferrite. An object of the mention is to produce a er>rib:nalion ol elements for use m u to que tiansniiti.r.g and or an energy absorbing d:vke ar.d partr.uiarly a biake wherein the uniformity of ope:.iti. r. is iir.provcd In earning out the above object i! is a further object ol the intention to reduce cvld p-dal cflc.t norm.Jly picsent m automotive braktne -vstci .s Turthe; objects and ..Jv .images of the picsen; ir.vention will be apparent from t:ie u-, low mg dc'ci ipnon. tefeicnee I'cir.g h :J to tt-. e.omp.ir.y ;r.g Jr.iwir.es wher. in pteierred embodiments ol the preset.; invention are clc.rly shown In the d. ,,vi .nps IK ! 1 's ,, phot, i ... oi ..ph o: " scent n of a S.\I into sue! J:um show.! ; the is :- '.. m the structure. a"J I 1C 2 rs a photo ir.'.roe .it n o ' . , o re - ve.tff n of a S.M lily* steel diiin; h.-u .' t1. al's.-t. of fciile in itic mict ostruetuic. Retcrt trends in automotive de-igr. tmj lmprov.J ro.i 1 Ci n.til.ons h. ve made ros-ibi. higher speed tr.iv. l in aiilomotivc vehicles. These Ire n 1- have requited impiovemcnt in brake Jev:gr. end e i.struction so fia.l me vehicles may be stopp'd within a s. distance even Item I1,, h-giie: spec.!' In o Jer ;( it. ike this condition posse'tv. heavy duty braU ! n re i,. iU--i.il' h,.\e K . n Je u ioped vvl.i.b jrc melalii. r..,..::e . nd which w.l1 w.lt. st.ir.J the high tempera!ur . conditions wti.ch prev.in in the brake duung a stop or stops from fc-gb. speed' This.temperature conditions aie si.iliinnt to. in many in-tan. . c..u-e eh.mine of nonnu' dlie typi linings incluJ.rc i-i ganie type material. Th-s new brale lining mateiiul whuh is specifically a sin.ei.J ferrous material iivlujire graphite, is disclosed in some det ii! in U S. 1'.items 2.945,291 and 2.945.^29. among -others which arc as signed to the assignee oi this app!ic..tion. These mctali'c friction materials have the ability to provide reasonably constant coefficients of friction over a wide range of temperatures find specifically are capable of maintaining the reasonably high coefficient of friction at high tempera tures whereby the vehicle may Ire brought to a stop with out excessive pedal pressure and wherein the fiiction ma terial remains unharmed due to the rise in temperaime These same materials, however, do not provide the ultimate in cold pedal operation under normal conditions. Cold pedal may best be defined as a reduction in effective ness of the brakes aflci a period of inactivity, that is. when the automotive vehicle has been standing iJlc fot a period of time, for example, the r rst stop or first few stop, made require printer pi !nl pressure to bring the cai to a stop than do subsequent opciations of the bi.ikiip s.stcm. This condition, wbiie not siriniis fiom a safetypoint of view, is nevertheless, annoying ar.d has ati-.-J a a Jeterrent in some case', toward the application of m- tnllie brake linings in pleasure vehicles. 2 We have found that cold pedal conditions may be greatly lessened by utilizing a ipecific combination of elements in the bnking system. Thus, when using a ferrous metal brake lining such as is disclosed, for ex 0 ample, in Patent 2,945,291. we have found that the colJ pedal effects are greatly lessened if a brake drum suriace formed from steel substantially free from ferrite is used in combina'ion therewith. Most automotive vehicles made today utilize gray cast iron brake drums. The 10 combination of the metallic lining With the aforementioned steel drum reduces the cold pedal effect in the order ci 25% whereby much better and more uniform operation is obtained from the braking system. A typical cold pedal test procedure is 2s follows: the 15 linings anj drums are conditioned by making ten stops at '/: mile intervals each from 40 miles per hour at a decel eration rate of 10 ft./see.2. 7 be vehicle is then parked for a minimum of two hours The cold pedal is then evaluated by making ten stops at : e mile in.ervals frcni ju 40 mi f per hour at a dec.lei.tlx n rate of in ft / sec s wheicin the initial and fit;;.! line presrurcs required to mair.la.n the spe. ffc deni:r..t'Oi is K.o'Jed i h r o cash slop Using brake iir.ines a` disclosed in the af-mcrr.ca' -.-i'. ' patent with a standard ta d ir.-r. drum cor.J.tioui! r. tr.- tenth stop of the schedule icqirred 270 p s : to p',\!...e the desired deceleration '.tier th. tar v p.us. J tor the two hour rest period fror,i . fervv,.rd 'top, the first chc.l step after the cooling off pc:..-.I required an in<t ;. line r-cs are <* 320 p.s.i.. v-hi.h r: -. be termed t r . ivi'd for.- -.-ft .,i vents; l it h e car V-. , ; , . . ' I : - -o ' ng. off p<::>,! from a reverse sb-p. the .ire:' ' >p i.- qu;rcd jn-lia! line pressure of eS ' p-.i 'lets m r. termed coid reverse effect:-.no- .. . If the car i- parked w tli .- iff" - ...1 slap hi?o\- the cooling pcrioJ arid a confodc-J reverse stop is made before the first che.k s op. the f" st -cb-c.fc -Up rcqirres an i n i t i a l I m e p r e -.ure o f 3 S " p > 1 T .hi; 1: a l s o Call ! li cold u \ c rse effcciiveness I t will b e r o t e . , t h a t t h e r ; p i ir r i c e v e te c f . a sp e c ific d e c e l e r a t i o n t o si: `P : . Ih c b.':rw t o effect - if t n e i m m e d i a t e p r e v i o u s si i ' p \s . 's a I ^ c r *; s t e p w h . t h the l e v e l s . - s t o p w a s b e f o r e c ; ;h U* lu i . T i ' l i n e off p e t is- 7'hiis the diltercnec between w .- ; n-..ki cflt.ovcr. at 270 p.s.i. and cold reverse ofie.' ciess at y.s i. p s i. This diilerensC w-ll 1c d.e.tc.l by trie dr'v .' cr.l is known as harder.. ! p.d. I 1' o^iur r r.irn .1 drome when .. d iver bask- out of .. pjrking spate -r.. then is i.quitvsi to make a for>\ id Map The change ft brake output is note.! rcg-.tdts-: - of the c..r - p ..J . Th. ;..:ik scheduled tc-t-. \u" . made us-ng drums formed fiom S3!: JUS' steel wall all other cond.t identical. In this instance th: warm effectiveness dropp-! _ to 2)5 p.s.i.. the cold forward effectiveness to 230 p I'''1 and the colJ reverse effectiveness to 25o p.s i. Thus, the steel durn narrowed the difference between the wan ; stop and the cold reverse slop to 35 p.s.i. over the 115 p.s.i. required when using a gray cast iron drum. In addition to the improved brake characteristics, stcci has greatly improved tensile strength o'er tbs used gia;cast iron, as is wrell known. Further, when iubst.-rtitdly free from ferrite, the steel has reduced scoring tcnJcnci.' This is a very important consideration since fu . fend, such as is formed in SAT 1010 steel p.oJuc.- marked C> scoring tendencies ar.d is not us ful in braking application' Steel offers another benefit that is commercially im portant. namely, due to the increased slrcngt- we: gray cast iron the drums m..y K m.ide consiJe .n lv l.ehtcr will', decreased wall lhi.kness witho-it sacrificing ruggi .1- ~<j ]* should hr understood that similar rcsi k ta r be obtained using cast iron drum' lined with the desire ' steel surface. Thus, when th: term drum is us;J herein 8,184,001 3 the term is sufficiently broad to include any combination providing the braking surface is substantially free from ferrite. In place of SAE 10R0 or 1085 steel any Other steel 4 or energy absorption over a wide range of operating temperatures. 2. A torque transmitting device compliant a liotcred ferrous facing and a mating surface cotafctmg of itecl which has a structure substantially free from fertile is g substantially free from ferrite. useful, for example SAE #8660, #9260. Alloy steels 3. A brake for use in an automotive vehicle and the of this character may also be used where specific physical like, comprising in combination; a sintered ferrous brake characteristics are desired which may be obtained from lining and a braking surface cooperating with said lining, the alloy. said braking surface consisting of steel substantially free In general, sintered ferrous linings and/or facings hav 10 from ferrite whereby the combination of the sintered fer ing a sintered ferrous base and including graphite in quan rous lining and the said steel braking surface effect uni tities above 10% with or without well-known friction form braking conditions over a wide range of operating fortifying and/or modifying materials, may be used effec temperatuies. tively in the combination. 4. A brake for use in an automotive vehicle and the Any steel drum having a metallopraphic structure sub ]5 like, comprising in combination; a sintered ferrous brake stantially free from ferrite when used in combination with lining and a brake drum for use as a rubbing surface a sintered, ferrous brake lining material will offer im against said lining, said drum having a contacting surface proved operational characteristics, particuhily in the cold consisting of steel substantially free from ferrite whereby pedal ranee. Such improvements arc easily noticeable the combination of the sintered ferrous lining and the said by the operator of the vehicle and lessen the difference in 20 steel braking surface effect uniform braking conditions pedal pressures required to bring a car to a stop unde: any over a wide range of operating temperatures. giv cn set of conditions. 5. A brake for use in an automotive vehicle and tbe It is to be understood tti.it the principles in'c'ved arc like, comprising in combination, a sintered ferrous brake equally applicable to disc brakes. drum brakes, clutches lining and a braking surface cooperating with said lining, and'or other torque transmitting and or cnergv absorb 25 said braking surface consisting of SAC 1080 steel sub ing device. wherein sliding or rubbing cnjneenu.nl occjrs stantially free from ferrite whereby the combination of bet era the sever..1 element- of the structure. Wb is the embodiments of the present invention as heteir disclosed, constitute preferred forms, it is to be under:tood that other forms might be adopted, 30 is el.timcel is as follows: 1. A torque transmitting and energy absorbing device, said sintered brake lining and said SAE 1080 steel braking surface effect untfo'm braking condili. r.j over a wide range of operating conditions. References Cited by the Examiner UNITED STATES PATENTS i ..iptising .n combination: a driving an ! a driven mem 1 900.804 3.73 C row e...........- ............... 188--218 ber herein one of sad members comprises a sintered fer- ,,. 2.09-.125 10/37 Le Je u n e ...................... .1 8 8 --218 ro.iv surface and wheretD the other of saiJ members con 2,945.291 7/60 Ankcnv c: al ________ 29--182 3 sist oi a steel surface suKiant.ally free from ferrite where by the combination of the sintered ferrous surface anj the ART HI 'R L. LA POINT, Primary Examiner. s.-.i-.l st.cl surface effect uniform torque transmission and' EUGENE G. BOTZ, Examiner. May 18, 1965 e . w . r e in s c h et al BBAKE DRUM AND LINING F ile d Aug. 16. 1962 3.184,001 500 X F i g . /. F i g . 2. vvEvroRS t o r / W Reinscl'. Gene P Boynes / he.r Attorney