Document rBV9aEY9N5g5oyogkDMeMeMN0

United States Patent U9j Mitchell [in 3,853,517 MS] Dec. 10,1974 1541 DUST COLLECTOR [75] Inventor: Wallace F. Mitchell, Arlington Heights, Dl. [73] Assignee: Ammco Tools, Inc-, North Chicago, III. [22] Filed: Mar. 12,1973 [21] Appl. No.: 340,324 [52] [51] [58] UA Cl.......................... 55/288, 15/352, 55/304, 55/334, 55/366, 55/374, 55/395, 55/459. 53/DIG. 3, 55/DIG. 6 tot. Cl................................................ BOld 41/00 Field o! Search............55/DIG. 3, DIG. 6, 337, 55/429, DIG- 26, 288, 334. 378, 293, 366, 372, 392,394,395, 399,428,459, 304. 374; 15/327 R, 327 D. 352 [56] 1.458.720 2,295,984 References Cited UNITED STATES PATENTS 6/1923 Malone................. ,,,,.... 55/337 UX 9/1942 Wilson .......-......................... 55/288 2,892^11 3,174/264 3,320.725 3,616,622 6/195# 3/1965 5/1967 11/1971 Gnll et at...................... _ 55/DIO. 3 MeKnab............................ 55/459 UX Foster...........................,,... 55/293 X Friedman.............. ....... 55/DtG. 6 X FOREIGN PATENTS OR APPLICATIONS 289,662 3/1953 Switzerland............................. 55/337 24,832 10/1912 Great Britain.......................... 55/429 Primary Examiner--Frank W. Lutter Assistant Examiner--Kathleen J. Prunner Attorney, Agent, or Firm--Edmond T. Patnande [57] ABSTRACT An inverted dust collecting bag has a plurality of weights including a magnetic member affixed thereto and a magnet mounted externally of the bag for opera tive engagement with the magnetic member when the bag is Inflated and for temporarily bolding the bag while the weights pendulum downwardly to wrinkle the bag before the bag drops from the magnet and falls abruptly to dislodge the dust particles collected therein. ' , 2 Claims, 3 Drawing Figures i I PATENTED DEC 101974 . 3,853,517 3,853.517 1 2'. ' . . . DUST COLLECTOR The present invention relates in general to dust col BRIEF DESCRIPTION OF THE DRAWINGS lectors of the type including a porous bag in which dust Further objects and advantages and a better under particles are trapped as dust laden air is forced into the standing of the present invention may be had by refer- bag, and it relates more particularly to a new and im 5 cnce to the following detailed description taken in con proved dust collector incorporating novel means for nection with the accompanying drawings, wherein: removing dust particles deposited on the inner surface FIG. I is a partially sectioned dust collector embody of the bag. ing the present invention; . FIG. 2 is a cross sectional view of the dust collector BACKGROUND OF THE INVENTION 10 of FIG, I taken along the line 2--2 thereof; and There is a serious need for an efficient dust collector for use with grinding and other industrial machinery FIG. 3 is another cross sectional view of the dust col lector of FIG. 1 taken along the line 3--3 thereof. which produce or handle fine particulate materials. DETAILED DESCRIPTION OF THE DRAWINGS Whether such collectors are of the pressure or vacuum type they commonly employ a fabric bag through which dust laden air is passed to trap the entrained par ticles on the inner surface of the bug. With certain 15 Referring.to FIG. I, a dust collector 10 comprises an air inlet and distributor unit 12 removably mounted over the open top of a container 14, and a filter unit 16 mounted on the unit 12. The container 14 may be a types of dust the bag surface becomes coated with an conventional five gallon pail of the type commonly almost solid cake which, long before the bag or associ 20 found in garages and machine shops whereby only the ated container is filled with dust, decreases the effi units 12 and 16 need be marketed. The filter unit 16 in ciency of the dust collector system to the point where cludes a housing 18 having a plurality of air outlet ports the fine particles are not collected but are transmitted 20 at the top and containing a fabric filter bag 22. The to the surroundings creating a definite health hazard. rim of the filter bag is sealably' held in place in an annu- Various means including vibratory bag shakers and re 25 lar groove 26 near the bottom of the housing 18 by a verse flow systems have been devised to clean filter spring ring 28. . . bags and other filter surfaces by automatically dislodg An air inlet duct 30 opens tangentially into the unit ing the filter cake therefrom. Such prior art techniques 12 and a plurality of baffles 32 extend inwardly from have, however, required the use of large, cumbersome the inner wall of the annular air inlet housing 34 to act and usually expensive equipment not suitable for use 30 as a cyclonic dam. to prevent the formation of a vortex - with small dust collectors of the type commonly associ within the dust collecior. The baffles 32 direct the in ated with individual machine tools or the like. coming air in a downward direction toward the con-, OBJECTS OF THIS INVENTION tainer 14 where the dust or other entrained particles are'collected. Air seals are provided between the top of Therefore, a principal object of the present invention 33 the container 14 and the bottom of the air-inlet section is to'provide a new and improved dust collector incor - 12 and between the rim of the housing 18 and the top porating means for removing filter cake from the inner rim Of the bousing 34 whereby all of the air entering the surface of a dust collecting bag. : collector. 10 must exit through the filter bag 22 and the Another object of this invention is to provide a new outlet pom 20, The inlet air pressure thus inflates the and improved method and means for removing fme 40 bag 22 into an inverted condition as shown in FIG. 1 particulate matter from the surface of a filter bag. and dtlst and other particulate matter entrained in the A further object of this invention is to provide a dust incoming air is trapped on the inner surface of the bag collecting system for periodic use, which system incor 22. When the supply of inlet air is interrupted, the bag porates a filter bagcleaner which automatically cleans 22 drops down against a rigid screen or grid 36 the filter bag at the end of each operating cycle. 43 mounted across the top of the air inlet housing 34. As thus far described, the dust collector .10 functions SUMMARY OF THE INVENTION satisfactorily with some types of particulate matter. The above and further objects may be realized In ac Where, however, a heavy tenacious fiber cake is depos- cordance wjth the present invention by sealably mount 30 tied on the bag surface, the cake remains on the bag when the air flow is interrupted thereby impairing the ing a filter bag above an imperforate container and efficiency of the dust collector.' feeding the dust laden air into the space between the In order to break up the filter cake and cause it to fall container and the bag to inflate the bag in an upward from the bag 22 each'time the air flow into the collec direction. In order to break up the filter cake deposited tor is terminated, a plurality of weights 38 are fastened on the interior surface of the bag, a plurality of weights 33 to the bag near the top thereof. A weight 40 in the form are affixed to the bag at spaced apart intermediate lo cations, and a magnet is mounted above the bag to of a plate of magnetic material such as steel Is fastened to the top center of the bag and a permanent magnet coact with one .of the weights when the bag is inflated 42 is mounted to the housing 18 for coaction with the thereafter to temporarily hold the bag in an upstanding 6() weight 40 when the bag 22 is inflated. As shown, the condition when the air flow is interrupted. When the air magnet 42 is mounted' for adjustable, vertical move flow ceases, the other weights thus fall and swing down ment on a screw 44threaded1y received in a central wardly from the area on the bag held by the magnet opening at the top of the housing 18. thereby to wrinkle the bag and crack'the filter cake. The magnet then releases the bag whereupon die weights and the entire bag fall abruptly against a grid ^ OPERATION Air in which particulate matter is entrained is sup through the openings of which the dust and cake fall plied under pressure to the inlet 30 from which it enters from the bag into the container.. ' the air inlet and distributor section 12. The heavier par-