Патент USA US2282620код для вставки
May .12, 1942. ' H.,¢. swn-T A z,2s?,62oy BRAKE Filed Jan. 16, 1941 FT51' ß. ~ ' ' mmm áherirCïSW/Fr Z» mßm* 2,282,620 Patented May 12, 1942; , UNITED . STATES PATÉNT '__joFF-ICE y . ,x .zasaszo ’ ams Harvey'c. swu'_¢,.netmu, man., [email protected] ny. . draulicV Brake Company, Detroit. Mich., arcor;4> i ‘ poration of California appueationianum is, 1941, sensi Naan-,15s.- _ s claims. (ci. iss-79.5) This invention relates to brakes, and'more specifically toï’automatic adjusters for the fric tionelements thereof. - " - . - Y Broadly the invention comprehends means for automatically adjusting the friction elements or shoes of an internal expanding brake to zoom pensate forvw'earon the liningsof the shoes »due to'repeated'braking operations.,> ' Generally‘fin the type of 'automatic adjusting v onk the shell.y Springs hold the 'lever adjacent its iulcrum and the member frictionally againstV thel same side' ci thefweb of the shoe.=' 'Fui‘therrobjects and' features of the invention _ will- appearV vfrom theiollowing description' taken of '-the speciilcation; and ‘in which Fig. lis a> vertical sectionalV viewjof'a brake ; _` taken just back 'of th'ehead Vof -the'drum illus' means wherein the operation is dependent upon trating the invention as applied; a differential of wear on the-‘friction linings of the shoes and a member frictionally clamped to tially on line 2-2, Fig-1; and the` shoes-andîvadapted for cooperation with the4 -` drum, and an' adjustable retractile stop formain' or drum engaging member. taining 'theîshoesl in proper spaced relation _to 'the` drum,v when the brake is at rest, a consid-»_> erable force is required to movethe frictionally clamped member relative to the shoe. It lis íalso understood that because of I'the tension ofthe retractile- spring-’connecting the shoes, there-is a tendency to displacement of the- frictionally clamped members when the shoes are returned _ in connectiongwith'th'e drawing forming'ra part' ` " ~ - Fig.' 2 is an-’enlar‘gedsectional view substan '» ` ~ ~ ‘ Fig. 3 is atop plan-'view_.of’the'ceramic block ' ' ' Referring »to the'IV drawing for more specific o“ details of the invention', Il) representsV ailxed' support or vbacking ipla‘te. Associatedwith the - backing -plate isf-"'a'rotatable drum _I2 ?and a pair of _ corresponding interchangeable' 'friction ele# ' ments or shoes i( and I6 mountedïon the [email protected] ingy plate for cooperation'with the drum. As shownythe shoes> are of conventional type each including ¿aweb' I8 supporting a rim> 2liV having I suitably secured" thereto frictional li_n-‘l cornes necessary for the -friotional resistance to movement‘of the members toexceed the load 25 ing 22. ¿The shoes Il and I6 have their articulate' ends pivotaily 'mounted on spaced anchors 24' an the `retractile stops, otherwise an underad and ‘26 positioned yon the backing plate, and cor--V justment `would result. A `It is the aim of 'the responding adjustable-retractile stops 28 and 30 present-invention‘to overcome this objection. to their retracted positiom> Accordingly, it be-_ An object of the invention is to provide means for automatically adjusting the friction elements or shoes of a brake to compensate for wear on the frictional linings of the shoes, operative _to avoid improper’adjustment thereof. _ _ A feature of the invention is a member sup ported on a- friction element movable relative -theretol and cooperating-with a drum and an ~ adjustable retractile stop and means interposed. between the member and the stop for inhibiting retrograde> movement of the member. _ f . Another feature of th'.` invention is a non frictional member erably> a ceramic high compressive agonally disposed of' 'impervious material, pref member of ñne texture and strength having one side di with relation ‘to the proille also positioned-'on backing plate support the shoes in 'proper spaced relation to the drinn. when the brake _is 'at rest. A retractile cspr'i`ng""22 >connecting the'shoes> il -and I8' serves to return the shoes to' lthe stops.”V and Iii-,upon conclusion of' a.v braking operation- andV to retain the' shoesonv the stops when the brake is at rest.v Each of_ theïstopsY includes a shaft.“ rotatable in the backing 'plate Il. Thel shaft has thereon a`co1lar'38 abutting the-backing plate and ilapsßß on its 'freefend I for the' receptionof an adjusting tool. f A washer I0 is sleeved onlthe `shaft and- a nut I2 threaded»~ on'the" shaft'serves _to secure the assembly in _ the adjusted position.- ’ A num pressure-actuated motor“ of 60h-, _of the member adapted to slidably engage an =f ventional type mmmted >on thejbackmg plate' between the shoes "il and I8 and adapted to be' arm rotatable on a pin carried by the forcé transmitting end of a lever anda shell support ing the pin adapted to eliminate dust and other foreign substances. More speciiically` the shell is fixed to the fric tion element or shoe and houses the ceramic member and forms a support for the movement of the member transversely` of the shoe. The lever is fulcrumed on the web of the shoe within the shell and holds the member against its seat connected to a suitable source of'ñuid pressure> L is operated to actuatelthe >shoes into engage-j 'ment with Vthe drum against the resistance of:` the retractile spring 3L . 1 _ , ' Mounted onthe shoes in reverse position are automatic adjusizersv indicated‘generally at 40.V As shown. the rims and the linings'r of the shoes are slotted as at 48; Thewebs of the shoes have' bores 50 and _arranged on the _webs are shells 2 . _ 2,252,620 / 52 spot welded thereon, having bores 54 there through concentric to the bores inthe webs. , block are reduced to a. minimum. Each> of the adjusters includes a lever 56 hav ing as its fulcrum a pin 68 fitted in an opening 60 in the lever and coextensive with the bores It is to be clearly understood that applicant does not limit himself to any particular ceramic in the production of the drum engaging member or block. However, it is important that such ce ramic as may be employed mustibe durable and substantial so as to withstand the shock and 50 and 54 to permit rotation of the lever. The lever 56 has an aim 62 of short radius and a driver end 64 suitable for> engagement with the associated adjustableretractile stop. , A block 66 of impervious non-frictional ma . a high degree that the abrasive properties of the strain imposed thereon in brake structures. 10 In a normal operation, -pon energization of terial has a slotted diagonally disposed side 68 the the motor 44, the shoes and I6 are moved carrying a metal insert 10 therein, parallel the ' into engagement with the drum I2 against the diagonally disposedA side. One end of the> block resistance of the retractile spring 32 effectively has a radius commensurate with the radius of retarding rotation of the drum. During this op the shoe and this end of the block is fitted for 15 eration, the respective assemblies of the auto movement in the slot 48 through the rim and matic adjusters“ and the shoes I4 and I6 move lining of the shoe and is adapted to engage the as a unit. V ' drum. The metal insert 10 on’the diagonal side Further movement of the shoes I4 and I6 into of the block bears against a curved portion 12 the drum I2 results from wear on the linings of of the arm 62 of the lever. One side of the 20 the shoes due to successive engagement of the block slidably engages the inner wall 14 of the shoes with the drum. There is no undue unit shell 52 and is-pressed against the web of the pressure exerted on the blocks 66 in comparison shoe by an arch spring 16. A thin washer 18 to the unit pressure on the shoes, the wear on the Iiapped-against the web of the shoe and a pin 80 drum engaging portion of the’block is nil as com passed diametrically through the pin 58 serve 25 pared to the wear on the linings 22 of the shoes, to hold the pin 58 in position as well as assist and this relative movement results between the in clamping the lever to the web of the shoe by blocks~ 66 and the shoes I4 and I6. bearing upon the shell to -place tension on a Movement of the blocks 66 is lrestricted to spring washerv82 received by the pin and in paths transverselyof the shoes I4 and I6 by the serted between the shell and the lever. 30 wall 14 of the shells 52. Upon wear of the lin Due to the differential in the coeillcient of fric ings 22, the shoes are caused to assume new po tion of the lining and the block, in a normal sitions relative to the block 66 and levers 56. 'I'he braking operation there is relative movement be movement of the blocks 66 upon wear of the lin tween the shoe and the block. This movement of ings 22 results in transmission of force through the block is proportionate to wear on the lining 35 the block and metal insert to the arm 62 on the lever causing a clockwise rotation of the lever. on the shoe and is transversely voi.' the shoe against theY resistance imposed by the spring 16, and during this movement force is transmitted by the diagonally disposed metal' insert 1li to the Hence, when the’driving arm 64 on the lever en gages the associated, stop, the shoe is supported in a newly adjusted position in proper spaced re arm 62 of the lever causing arotation of the lever 4.0 lation to the drum,- ready forrfurther‘braking operations. ' _about its fulcrum point, the pin 56, so that upon conclusion of a braking operation and return of Extremely small pressure is required to move the shoe to retracted. position the lever engages the blocks 66 inwardly; whereas, outward move the retractile stop and supports the shoe in ment is inhibited due to the frictional resistance proper spaced relation tothe drum. Because of 45 imposed by the spring 16, and movement ofthe the wedging action on the block between the wall block when the brake is at rest is inhibited due 14 of the shell and the diagonally disposed metal to the wedging action on the block between the side 10 of the block, retrograde movement of the ' wall 14 of the shell and the diagonally disposed block is inhibited. 'I'his is of vital vimportance metal side 1U of the block; hence, the tension of because of the tendency to maladjustment of the the spring 32 connecting the shoes does not re brakes due to the snapping action of the retrac suit in maladjustment of the block. tile spring 32 connecting the' shoes upon release While this invention has been described in of the brake at the conclusion of a braking oper connection with certain specific embodiments, the principle involved is susceptible of numerous To reduce wear on the drum to the minimum, other applications that will readily occur to per .' the adjusters are Larranged in reverse position sons skilled in the art. The invention is, there-with respect to one another so that in a given fore, to be limited only as indicated by the scope ation. ` ' brake structure the wear on theïdrum` may be spread over substantially twice the area of a drum structure wherein adjusters are arranged in diametrically opposite position to onemanother. This has another highly important advantage in that the adjusters may be alike in structure and accordingly the cost of production may be greatly reduced. ` Wear on the drum is further and very mate rially reduced by the introduction of a drum en gaging member of the character of the block 66. This block is made from impervious non-fric tional material preferably a ceramic of ilne tex ture, durable, high compressive strength, sub stantial, and wear resistant. In practice, the face of the block engaging the drum becomes im pregnated with fine metallic particles and this results in polishing the face of the’block to such of the appended claims- I claim: i 60 _ ' - v ' 1. A brake comprising a movable member, a friction lelement for cooperation therewith,v a stop for the friction element, a member carried by and movable transversely of the friction ele ment having a side angularly disposed to the path of movement of the member, a support on the i friction element for the member, and a lever ‘piv- - .oted on the friction element having a part en gaging the angularly disposed side of the mem ber and another part for cooperation with the stop, said support providing a bearing‘for the lever pivot. 2. A brake comprisinga movable member, a friction element for cooperation therewith, a stop for the friction element, a member adapted to engage the movable member carried by and mov w... 2,282,620 c 3 able transversely of the friction element having a part angularly disposed to the path of move viding a bearing for the lever fulcrum and hav ing means for frictionally clamping the member ment of the member, a lever fulcrumed on the friction element having a part engaging the an to the friction elements. - 6. A brake comprising a rotatable drum, a fric tion element for cooperation therewith, a re gularly disposed side and another part for coop eration with the stop, a shell fixed to the friction element housing the transversely movable mem tractile stop for the friction element, a member carried by and movable radially relative to the ber and the lever fulcrum, and spring means within the shell holding the lever and member friction element having a part adapted for co operation with the drum andV another part an toward the friction element. ' gularly disposed to the path of movement of the 3. A brake comprising a rotatable drum, a fric member, a support for the member, and a, lever tion element for cooperation therewith, a stop associated with the friction element, a drum engaging member carried by and movable trans versely of the friction element having a side angularly disposed to the path of movement of the member, a support for the member iixedly the short arm of the lever abutting the member to provide for slidabie movement of the mem-. fulcrumed between the friction element >and sup port having arms of different radii, the end of ber on the support. , l 7. A brake comprising a movable element, a friction element for cooperation therewith, an adjustable retractile stop for the friction ele ment, a member carried by and movable trans operatively abutting the member and having its versely of the friction element, a lever fuicrumed opposite end cooperating with the stop, said on the friction element adapted tor cooperate member being movable along the support. with the ‘movable element and having apart 4. A brake comprising a fixed support, a ro angularly disposed to the path of movement of tatable drum associated therewith, a friction ele ment on the support having a lining for co 25 the member, a shell on the friction element shel tering the member and lever fulcrum and con operation with-the drum, a retractile stop for the stituting a support for slidable _movement of the element, a drum engaging member of impervious member transversely of the friction element, said material carried by and movable transversely on lever having one part engaging the stop and the element having a side angularly disposed to the path of movement of the element, a lever 30 another part engaging the angularly disposed part of the member `holding the member toward fulcrumed on the friction element, a driver on secured on the friction element, and a lever ful crumed on the friction element having one end the lever adapted to engage the stop, an arm forming _part of the lever bearing on the mem ber, a shell iixed to the friction element housing the member and the lever fulcrum, and springs acting independently upon the lever and the member holding them frictionally against the friction element. ' its support on the shell. 8. A brake comprising a fixed support, a ro tatable drum associated therewith, a friction ele ment on the support for cooperation with the drum, a retractile stop for the friction element, a shell fixed on the friction element, a member `housed within the shell and carried by and mov y able transversely of the friction element and 5. A brake comprising a movable member. a ~ friction element for cooperation therewith, a stop 40 having a side slidabie along an inner wall of the shell, said' member havingl a side cooperat for the friction element, a member carried by ing with the drum and a part disposed diago- „ and movable transversely oí the friction element nally to the path of movement of the member having a side diagonally disposed to its other transversely of the friction element, and a lever side, a lever fulcrumed on the friction element having a part contiguous the diagonally disposed 45 fulcrumed on the friction element Within the shell having a part abutting the diagonally dis side of the member, and another part for co posed side of the member and another part for operation with the stop, and means âixedly se cooperation with the stop. cured on the friction element for supporting the member in abutting relation to the lever pro "ifka.n ARVEY C. SWIFT.