Патент USA US2404397код для вставки
July 23, 1946, J. G. oE'rzEL _ 2,404,397 ` A PRESSURE ACTUATED BRAKE MECHÀNISM Filed Novl e, 1944 Ely-f» '47 40 2 sheets-smet 1' July 23, 1946. J'. G. og-:TZEL - 2,404,397 APRESSURE ¿c1-Umm BRAKE MECHANISM -Filed Nov. 6, 1944 56m .2 sheets-sheet 2 ,9, 44.W4H ma 0 L w Wœ 4, , 6 ,mayo w ,N „d z _ , wfß M ...„ „ff . 7m .wgN _ Jw a @my, ' Patented 4July 23¿ 1946 ” 2,404,397 . UNITED' STATES PATENT Y 2,404,397 voifriclë: PRESSURE ACTUATED BRAKE ` I a ‘ ’ r rÍIHECHÍANI SM ÍGeorge Oetz'el, Beloit, Wis., assignor to". pany', WarnerSouth _Electric Beloit, Brake Ill., Manufacturing a corporation ofCom‘Illi-’V i. I ' , lapplioaiionnovemboro,1944, serial No-56ai1à l" s claims. (C1. 1ss_141) “This” 'invention relates to a `brake 'mechanism of the internally expandable'type energized in response to Afluid -~ pressure changes. Oneobject is to providefa brake mechanism ofv this‘character by which a substantially greater retarding torque is Vvobtainable than in prior „ mechanisms of the same type. , A more detailed> object ,isto augment the ñuid pressure source applied to a’ main brake element through the intermediary.V of 'an auxiliary friction element-_ ' - , . , f ._ . ' I -The invention also‘re'side's in the novel manner of mounting the-fluid pressure Aactuator so -that its-available force maybe' utilized to `best me chanical advantage.V „ ` r , Other'objects and advantages or the invention will become apparent'frcm the. following ldetailed description taken in connection With'the accom panyin'gl drawings, in whichv y I 2 l. K j Contractile springsV I.'I stretched between the shoe brackets I4 normally maintain the main friction element contracted with its shoe surfaces I5 en gaging the abutments I6 as shown in' Fig. ‘1, the main brake then being released. . ì " The main friction element `is expanded against the drum by a' forcel derived infpart from the momentum of the rotating part; This is accom plished through the medium o_f an auxiliary fric tion element engageable‘in this instance withy the inner >end portion of the drum surface 5 and movable bodily ‘with the rotating drum through an angular distance suliîcient to expand the main element.- In the present instance, _the auxiliary 16 element comprises a. pair, of r semi-circular shoes \ 20 covered with friction‘inaterial 2l and arranged in end-to-end relation with their adjacent ends spaced apart and disposed _on diametrically op posite sides vof the’ drum but angularly spaced ‘ Figure 1 is an end viewrpartially in section of 20 from the ends of the main shoes 9. a brake mechanism embodying the novel fea tures of the present invention, the section being taken along the liner I-I of Fig. 2.k Y I Fig. 2 is a section taken along the line 2_2 of Fig. 1. - - ` ' ' vFigsf'3 and fiarevi'ews similar togFigs. land 2 showing a modiiiedwform _o_f the_invention,.the sections being takenly long the lines 3+3 and 4-_4 of Figs..4 and ‘3 respectively. ‘ , _ ` ' I The brake',m'echanismsfvshown for purposes of illustration are 'adapted for' expansion of their friction .elements-- into gripping l engagement with thev internal cylindricalsurface r5 of .a drum 6 The shoes 20 are supported on the peripheral surface 22 of a second anchor member 23 whose hub 24 is jour- ' naled on the hub 25 of the ñrst or non-rotatable anchor member II. Outwardlyiprojecting arms 23a on the second anchor member `23iprovide oppositely facing abutments 26 engageablewith plates 21 on brackets 28 which are secured'along the center line and on the inner Vsurface of the auxiliary shoes 20. Contractile springs 29.'nor-. .valo mallymaintain these shoesycontracted against the abutments 26. . ` v- \ rwhen the auxiliary friction sho-esilio are'ex- f panded into vgripping engagement with the rotat ing the corresponding endswîll. anchor on ed in the usual way 0n alyehijcle ‘wheel'or other 35 the drum, abutments 26, and the shoes, vtogether with rotary part whose motionlis to be controlled. In the anchor member 23.-will turn lbodily with the this instance, vÍthe‘drum andthe vehicle wheel having an inturned flangelfwhich may be mount rotate about'a stationary axle 8 projectingaxi ally through the drum, , . l 1 . The mechanism shownin Figs‘l and 2 isespe cially adapted for _the use of air as the- actuating iluid.í„This mechanism` includes a main friction element adapted’fvor .expansion against the> zone drum in the directionof rotationv of` the latter. This motion of the shiftable anchor is multiplied mechanically and applied to the corresponding ends of the main shoes 9 to~expand`the- latter against the drum. For this purpose, crank arms 3I project radially inwardly. from `pivots 32'which extend between spaced portions 33and 34 of the main anchor II and are disposed adjacent the drum surface 5 between the ends of each pair of main shoe ends. At their inner ends, the crank arranged in end-to-end relation with their .ends arms 3| have slots 35 receiving pins 36 which pro spaced apart on diametrically opposite sides Aof ject from the Iioating anchor 23. Projecting from the drum. `The shoes are supportedby an anchor opposite sides of the crank arms intermediate the member. in .the .iorin‘cfA a casting „Il , fastened 50 ends thereof are pins 31 which are engageable by" Lbolt's ’I2 to a _flangeflíi on the axle .ßfand‘s‘ubà with the ends 38 of the brackets I4 on' the mainV stantiallyïclosing -the- openend :ofmtheî drum. of tlie‘surfac'ef5 ne'ar the open end of the drum.> The' element. is rcomposed ofy two semi-circular shoes .,9'covered vwith friction material . I0 and Bracketsv I4 Welded to vthe inner sidesÍof _the shoe endsprovide .abutment ` surfaces I5§ engageable wìthLIabutments rI6 on the anchor Amember ÁI I. shoes 9, these bracket endsstraddling the crank. Thus, one shoe end 38 will be moved away from its anchor I6 as the crank 3| is swung from the` brake-released position shown-_in Fig. 1 tothe 27,404,397 .1Q Í ” 4 actuators may have comparatively short strokes determined by the maximum shoe clearance ob tained in service operation between the auxiliary shoes and the drum. When the actuating fluid are returned i pressure is relieved, all of vthe parts _ l y , position shown in phantom. After normal clear , ance has been taken up, the shoes 9 engage the drum andare held pressed against the latter so long as the auxiliary friction element remains energized. Upon contraction of thelatter, the to brake Areleased position. by: the“- action of the springs 'l1 contract themain friction element and ‘springs |1 and 29. ` return the crank arms to released position. , ,y The ends of the auxiliary shoes are spread apartv . , , ‘ . Figs. 3 and 4 show’ a modification of the im proved brake mechanism adapted for actuation ` by iiuid pressure Operators 40 which, in accordance " i with the present invention,'are mounted >on 'thefmîg hydraulically. In this form, the main and aux È iliary friction elements are mounted and inter l ñoating as to minimize anchorthe member 23 to travel therewithlso length of the actuating strokes . ` ' connectedin the same manner as in the mech Í-a-nisnr..ñrst described, and the various parts are In Figs. 1. and 2:,.theoperators' 4 _ » 49 comprise air cylindersA'Iff» angularlly spaced "y correspondinglynumbered. In this case, how ever, the cylinders24| of the hydraulic actuators ` around the drum from the shoe ends 28 and se 40 are smaller in diameter vowing to the higher, cured as by welding to the exterior of the hub 24 _ , of the operators. l on the anchor 23 with the axes of the' cylinders `f pressures that may be employed, and are dis j secured to the hub 24 and communicating through thatY the piston motions are thus applied directly ï aflexible conduit 44 with a ñtting45 onthe pri-L ,apart against the Yaction of the returnsprings 29'.' which, v'in thisfinst'ance, extend fromthe parallel to each otherf and extending along chordsj ` posed» immediately adjacent the ends of the aux-> ' iliary shoes. The pistons 41 ‘ are connected I of the drum axially spaced inwardly from the through the .links 48 directly to pivot pins v58 on cranks 3|. l Conduits '42" communicate'«with> the the-,brackets 28. of the. auxiliaryv shoes` 20 so 1 centers of the cylindersïand lead to a fitting to »spreadthel ends of; the auxiliary shoes» ‘x20 i mary anchor ||„ A conduit 46 extends'frorn the latterA fittingthrough the anchor || and is Icon . brackets 28 to points on _the -floatingyanchor V23. . The operation of this form of _the brake is iden- ' nected to a pipe- 51 Vfor conveying compressed air ` to the .brakermechanismffrom afsuitable source ` of supply, tical> with that vof. thev first form. describedî above. the delivered pressure being regulated . . ItA willbeapparene from the >foregoing that .the i inthe usual' wayby a suitable valve. Within each cylinder 4| are two pistons 41 con- I' s ì nected to ,links 48 which projectthrough dia auxiliary 'friction element which is> energized-4 by ` the pressure actuated..devices derivesan actuat ing force from the momentum of thepartito be ; phragms 49 -and _from opposite Yendsof .the cylin» braked which force is applied tothe mainshoes ject in the same direction from the two cylinders 35 and in magnitude is many times that of thelpri marypactuating force. .Bothl-the main and. aux -are pivotally connectedfto r_the long. arms of bell iliary >shoes s ,may> anchor . at .either ...end yso «that cranksâ'l which areful'crume'd on pins 52 circum» the full lengths vofall four >'shoes are effective in f ferentially spaced apart andprojecting inwardly either direction of drum; rotation.,l Therefore, Vfrom the .floating anchorV 23 and parallel to the even thcughthefluidpres'sure is derived by Yman which drum- axis. projectThe .outwardly bell cranks and have have_short rounded arms _ends 5t*> i ual effort, apowerfu-l retarding torqueis pro duced without the'` necessity of employing large 54 bearing against .the-ends'55 of extensions on mechanical ratios in-.the force transmittingk con ' the 'brackets 28 o_f the auxiliary shoes 20. The nections and with dangerv oían. uncontrollable bell cranks are bentj as shown in Fig.- 2 to permit ders. The out'erends of'those links which' prof . wrapping actionvbeing developed. of suchoverlapping. . y ~ ~ ' application is a _continuation-impartîof With the parts‘disposed in brake-released posi-Y 45 my.This co-pending/ application SerialN'o. 448,251, tion shown and the drum turning clockwise, the brake mechanism'shown in Figs. land 2 oper ates in the- following manner> in response to the admission; of pressure ñuid to they cylinders; _4| I'claim as myinvention; i , . i 1. A brake mechanism having, inl combina tion„ two shoes arranged endv to‘end withtheir pairs >of ends spaced apart, an anchor member, through the conduit 44. Bothv pistons ¿in each cylinder iirst move outwardly, and, through' the anchors for said shoe ends carried by Y medium of the levers 5|, move all ‘four ofthe ' labutment said member, twopairs ofbell-,cranks respec shoeends 21 away from the anchor >abutments 26. supportedl by circumferentially spaced piv Assoc/rnÍ as- the> shoes engage the drum surface ' «tively ots ñxed relative to and carried by said anchor 5, they shift bodily with the drum'until’their lead? member. adjacent said shoe ends, the bell-cranks ing ends, as determined _by the direction of drum rotation, com'eagainst their'anchors 25, where-Ã uponV the Yother> shoe ends move farther away from.l their anchors and receive the full actuating I force developed by the respective actuators 4D. ' ' The reverse action takes place when the brake is' applied with the `drum rotating counterclockwise‘ The friction force resulting from engagement; of the auxiliary shoesv 20 with the drum moves' theseA shoes and their floating anchor 23 in the direction of d-'rum rotation, whereupon 'the pins 35y swing'theV crank arms 3| to the'positionjshown .in phantom in- Fig. 1,Y thereby movingthe'corre-> sponding ends 38' of the main shoes 9' away from their anchors V|§|5 so vas to expand the main' fric-ï tion`V element.“ _Inasmuch as the fluid’pr'essure actuators >4|) are’mounted on the floating anchor 23kto shift therewith, it is unnecessary for the operators 45 tov takeup the motion incident to', actuation of the main shoes. As >a- result, the fluid" of each'pair having short arms engaging the ends of onepair of shoes and long arms extending- cir cumferentially in opposite directions, two fluid pressure cylinders stationarily mounted with re spect to said anchor member, their Vaxes extend! ing parallel to eachother between saidl pairs of shoe ends, two pistons in each of saidcylinders respectively connected to two of said long. arms, and' pressure fluid supply'means communicating with the interior of said cylinders between V,the pistons Itherein. _ K ` ` ` 2. A brakemechanism having, in_combination, two shoes arrangedl endto _end with their pairs " of , ends spaced apart, ananchor membenabut-V ment, anchors> for ~said, shoe yends ' calrrie<`j1> by' said ' member' andy permitting _movement _jo-f ._ the shoe. ends circumferentiallyaway from the anchors; two 'pairs 'of f levers forÍ actuating fthe respective shoe 'ends eachY pivotally supported by’said'm'em- ^ 52,404,397 5 ber, the levers of each pair extending circum ferentially in opposite directions, two iiuid pres sure cylinders stationarily mounted with respect to said member, two pistonsin each of said cyl inders, and means connecting the pistons in each cylinder to two levers of the different pairs and actuating the levers unidirectionally in response radial expansion while anchored on said mem ber, a second anchor member mounted on said first member to turn about-the axis of said ele ment in either direction .away from a normal l brake-released position, a pair of auxiliary fric tion elements arranged in end-to-end relation. and having pairs of separable ends adapted to to a pressure increase. ' anchor selectively on said second member, a 3. A brake mechanism having, in combination, pair of fluid cylinders rigid with said second an expensible friction element having ends spaced anchor member and each having a pair of pistons apart, a member providing an anchor disposed therein, means connecting said four pistons to between said ends, two pivot pins carried by said the respective ends of said auxiliary friction - member providing axes which are fixed relative elements to separate the ends of each pair in to the member and are disposed inwardlyr from response to an increase in the fluid pressure in said ends and circumferentially spaced apart, a 15 said cylinders, means for conducting pressure bell-crank fulcrumed on one of said pins and fluid to said cylinders between the pistons there having a short arm bearing against one of said in, and means connecting said second anchor ends and a long arm extending across the other member and said main friction element to ex of said pins and circumferentially around said pand the latter upon movement of the second drum, a second similar bell-crank fulcrumed on 20 member in either direction away from said brake the other of said pins with its short arm bearing released position. , against the other of said ends and its long arm ex 7. A friction brake mechanism having, in tending circumferentially in a direction opposite combination, an anchor member adapted to be to that of said first mentioned long arm, two par mounted non-rotatably, a main friction element allel cylinders, and pistons in said cylinders re 25 of annular form mounted on said member for spectively connected to the free ends of said long radial expansion and to anchor on the member, arms. a second anchor member mounted on said first 4. A brake mechanism having, in combina member to turn about the axis thereof in either tion, an expansible friction element having separable ends, a member providing an anchor 30 direction away from a normal brake-released position, an auxiliary radially expansible friction disposed between said ends, a bell-crank ful crumed on said member to turn about an axis which is fixed relative to said member and which is disposed adjacent said shoe ends, said bell element of annular form anchored on said second member and supported thereby for bodily angular movement therewith about the axis of said first element, a fluid cylinder rigid with said sec crank having a short arm bearing against one 35 ond anchor member and having a piston therein, shoe end and a long arm extending circumfer means connecting said piston and said auxiliary entially around said drum, a second similar bell friction element to expand the latter in response crank fulcrumed on said member adjacent said to `an increase in the fluid pressure in said cylin shoe ends with its short arm bearing against der, and means connecting said second anchor the other end'and its long arm extending cir 40 member and said main friction element to expand cumferentially in va direction opposite’to that of the latter upon angular movement of the mem said first mentioned long arm, twov parallel cylin ber'in either direction away from said brake ders fixedly mounted with respect to said mem released position. ber, and pistons in said cylinders respectively 8. A friction brake mechanism having, in connected to the free ends of said long arms. 46 combination, an anchor member adapted to be 5. A friction brake mechanism having, in com mounted non-rotatably, a second anchor mem bination, an annular» main friction element ber mounted on’ the first member for angular adapted for expansion of its peripheral surface movement about an axis, a main friction ele by circumferential separation of its ends, a non rotatable member providing an anchor for said 50 ment concentric with sai’d axis and adapted for radial expansionwhile anchored on the member, element, a ring journaled on said member to an auxiliary radiallyexpansible-friction element turn about the axis of said element, an annular concentric with said axis and anchored -on said auxiliary radially expansible friction element second member for bodily angular movement having separable ends adapted to anchor on said ring, a cylinder rigid with said ring with its axis 55 therewith, a fluid pressure operator having a cylinder and mounted on said second anchor extending along a chord of said auxiliary friction member for angular movement therewith,` means element, pistons within said cylinder respectively connecting said operator with said auxiliary fric connected to the ends of said auxiliary element tion element to expand the latter in response to to separate the latter upon an increase in the iiuid pressure in said cylinder, and means for 60 an increase in the fluid pressure in said cylinder, and means connecting said second anchor mem introducing pressure fluid in said cylinder be tween said pistons. ` ber and said main friction elementV to expand , the latter upon movement of the second member~ 6. A friction brake having, in combination, an in either direction away from said brake-re anchor member adapted to be Vmounted non leased position. rotatably, a main friction element adapted for 65 JOHN GEORGE OETZEL.