Патент USA US2406440код для вставки
Patented Aug. 27, 1945 2,406,440 v UNITED stares PATENT orrlrcE BRAKE Christian H. Sauer, Chico, Calif., assìgnor to J. T. Alm, Chico, Calif. Application May 8, 1943, Serial No. 486,174» 2 This invention relates to brakes in general, and more speciñcally> t0 a brake and braking system that is applicable to aA railway car. One of the objects of this invention> is the pro vision of an improved braking system in which conventional brakel shoes are actuated by hy draulic or pneumatic means and~ in which system the actuation ofY said means causes the body of thev vehicle or'railway carto be pulled in a down ward direction when the brakes are applied to thereby- stabilize the car with respect to rocking, swaying or bouncing of the body,r and to al'so‘in body on the frame members and‘wheels; At each end of each side frame member 6 is` azshock ab sorber device I c that may be of the conventional,- hydraulic, single acting type such as shown andi described in my Co-pending application for’pat ent, Serial No. 482,851, liled April 13,71943'g`andi which device includes an arm II thatisgspringï urged downwardly at its outer end' at all times about a Divot point at I2», but which armfisÍ checked in- its upward swinging- movementy by" ' liquid in the shock absorber device. This typcof` shock absorber in itself~ is oldandwell knownto crease the frictional resistance between Athe car those skilled in the art. and the rails or ground. Theouter end of veach'arm I I is connectedwìth the body 9 by a generally verticallydisposed chain ' Another object of the invention is theprovision of improved means for more eiìciently applying the braking force to the wheels of a railway car through a pneumatic or-hydraulic system in which the braking action on a plurality of Wheels in a v " , or cable I4. The use of a ñexible connection be , tween each arm II and the body is quite im portant, and such connectionA may be' aV chai-n, cable, or articulated links; provided upward move truck at one end of the car or in all of the wheels ment of the arm I I unde1` certain circumstancesis of the car is equalized. permitted, as will later be described. . f > Other objects and advantages will appear in the drawing and description. In the drawing, I ` Fig. 1 is an elevational'view of a set of'wheels on a railway car showing the invention. >Parts‘l are broken away for- clarity and only'part of the body is'shown. ' ~ » ' ’ ‘ Adjacent each of the wheels is a generallyup wardly extending arm I5 that is pivotallyfm-ounted intermediate its ends on a» pivot I6. VAbove each pivot I6, each of said arms carries a brake shoe I1 of 4substantially the conventional type. EachV shoe I1 is pivotally- supported on the upper endv of each arm and is yieldably held in position away from the wheel, but with its curved wheel-tread Fig. 2 is a plan view of the wheels and braking elements of' Fig. 1, with the body removed, and 30 engaging surface generally concentric with ` the certain parts being in section. . wheel, by means of a spring I8. Spring |18 is-be The set of wheels shown in Figs. 1 and 2‘may tween rods I9, 20, the former being connected with constitute all the wheels of a single car, such as the brake shoe and the latter being secured to the~ some of the small street cars now in use, but gen body 9. Upon pulling the lower end of each arm erally the same principle is involved in the trucks |5` in direction awayy from the wheel- adjacent at opposite ends of a car, some of whichV have ` thereto, the shoe I'I will be carried into engage three pairs of wheels instead 0f only two pairs. ment with the wheel-tread, and upon release of Such modifications as may be required for differ ent systems do not change the general-manner of ' the force on the lower end of each arm- I5, the operationvof this invention, hence the illustrations 40 by spring I8 Yand also the arms I5 will be restored andA description are not to be considered restric tive of the invention, but are illustrative thereof' instead. In the drawing, two pairs of Wheels I, 2 are shown on tracks 3, and which wheels may be se cured> on( the ends of axles @that are journalled at their ends in conventional journal boxes 5 for rotation ofthe wheels. ’ Side frame members Sconnect the wheels I, 2 at shoe will be returned to full line position of Fig. 1 to their positions, as shown in Fig. 1. On the lower ‘end of each arm I5 is a 'pulley 2 Il, and a cable 22 that is secured at one endv tov thel body 9, extends d-ownwardlyacross a side of each . pulley and then horizontally to pivotally connect at its opposite end with one end of a link 23. There is a cable for each shoe and the cables thatV pass over the pulleys that are adjacent wheels I are arranged so that'their horizontally extending each side of the set, which members may extend end portions extend toward lthe similar portions> between the journal boxes, and cross-frame mem bers T extend between the pairs of wheels and of the cables that pass over the pulleys that are connect said side frame members. , Leaf- springs 8 between the body 9 of' the car and' the frame members 6» yieldably support the adjacent wheels 2. y There are four links 23 (Fig.v 2) arranged in pairs at opposite sides of the vertical mesìal> plane 65 of> the car. The links- at' saidl sides extend' con 2,406,440 4 l vergently toward said plane when the brakes are , the cylinder may be equally transmitted'to the l released and their divergent ends are the ones, , connected tothe cables 22. The opposite or con brakes and to the body. members. , . Vvide means for bodily shifting the arms I5 to~ ward or away from the wheels adjacent thereto 1 25. These bars 25 extend at right angles to frame i . quick adjustment of the brakes, I’preferably pro# § vergent ends of the links are pivotally connected j to opposite ends of a pair of parallel spaced bars l . While Vthe use of turnbuckles 26 provides a by means of bolts 4I) (Fig. 2) that extend through slots in the basesl of the bracket members 4I (Fig. , One pair of links 23 at one of the ends of bars 1) to which said arms are pivotally connected i 25 are connected intermediate their ends by mem bers 2B, @each of which may be in the form of a ‘ by pivots IB. By loosening said bolts the bracket ï turnbuckle havingits opposite screw rods pivot- i members may be .slippedï vtovitard or away from By turning the' '..11 L‘the wheels until the brake shoes are properly positioned relative to the'latter. Of course the , buckle of each member 25 in one >direction or the ' f ally connected to said links. l other, theV ends of said links 23 may be adjusted i relative to each other. - .Y . " ,s . ' connections between arms I9 and the brake shoes Vmay also .be adjustable so as to change the an gularity between the Shoes and rods I9 so that the wheel tread engaging sides of the shoes vwill members 28 that are also parallelY with side- ` ' uniformly engage the treads when brought into , v Frame members 21, parallel with sidel-frame.,` , members 6, slidably support links23 whileuframe „ frame members 5, and that extend between cross- ` ' engagement therewith. ' Y' , frame members 1, slidably support the bars 25. ' By positioning the pivots I6 substantially «Betweenjoars25 is an air or hydraulic' cyl* nearer the brake shoes than to the pulleys 2 I, it will be seen that considerable braking force is applied to the wheels upon pulling the lower ends of the cables 22 through actuation of the links indeIeZSlr having thev conventional piston therein i normally'positioned adjacent the head of the cyl inder‘withwhich the iiuid pressure line'3ll con t nectsgfor admission of fluid under pressure intoY 25 thefcylinder Abetween said head and piston. A conventionalcoil Vspring inthe cylinder yieldably hol'dsthe rpiston adjacent said head.A This air cylinder piston, and controls therefore are prac ticallyÍv-aslold ¿as air brakes andare familiar to , aëlyo'ne skilled _in the art; Piston rod VEII extending from ysaid vcylinder 29 ‘ 23. ’ y ~ . ~ . l. . The application of thebrake shoes to the Lipper Vhalf of the wheels I >haveiound to be much preferable in its results than by applyingV the brakes tothe lower’halfv of .the wheels where -they4 are ordinarily positioned This positioning of - the brakes provides ¿a„¿more_efñ_‘cient braking Vac tiongparticularly where a do-wnward force is also` ' transmittedto thebody 9. Y Y e y, is lpi'votally connected at its ¿outer end with one In I theV arrangement herein Y described, thev cfg-the bars 25. at a pointrinterm'ediate the ends ofïthe latter', ¿the head of `the cylinder that `35 means for pulling the body downwardly is asso ciated with the brakes, but the torque from the isnOrmally adjacent the piston is pivotally con-> ne'cted with the vother bar‘ 25 as at 32'at a point i . rotating -,wheels-does not Vhave'. .any particular ' tional trailers, etc., and while not aseiîfective in `such latter vehicles as the systems shown in. my co . eiîect on the force that pulls downwardlyon'the intermediate the ends of the latter. body.V This principle may be lapplied _to any> ¿frhe-bargawith which the cylinder head is; connected maybe connected'with the conven 40 vehicle. having brakes, `such as automobiles, emergency _hand A brake (not ‘ shown) î through ¿the usual` connecting mechanism that - includes’rod 33 V(Fig. 2) „While a member 34emay extend from the; other bar A25` over the/frame member 'I that is adjacentthereto. By provid-` ' ingf’a hook 35 on the „outer-end of member 34, ` theemergency brake will function to actuatethe Y vbrakes> _independently of the use of ¿compressed ~ fluid »in'thevcylinder 29. Y Y ffrStops SIìonframe members 28 projecting up ‘ ward-.ly therefrom'will engage one or more of the -v pending application for` patents:aboveqnentionedg; it does ltend to stabilize the Vbody'during braking. Theshock _absorbenelementslû will be Vseen toV function'upon application of the brakes in re stricting the objectionable upward movement of , the body and rockingV or swaying that occurs,A C when brakes are applied. When the body is pulled downwardlyby the l cables 22, these ide, vices also .prevent sudden >upward movementpt. the body when the brakes are> released. .The Varrangement of these elements I0. is also such or failto function.: i that Vthe body of the car will not lurch, as at In- operation, assuming I, the car is moving to-‘ wardrthe right, as seen in the drawing, andthe y 5; present, when it is started too quickly, and the lurch is also substantially reduced ,when _cars are airis >applied through line 30, the head and coupled together, thereby reducing damage from piston' of the, cylinder, 29 will move apart under ; the shifting of loads in .the car aswell as reducel equal force. This movement will cause links 23 " links- 23 'should any one of thev cables 22 break to pivot on members 26 in a-direction for moving , ing :the wear and tear on cars. y » In the claims and description the use of the their ldivergent ends `toward each other. This 60 >`termv “fluid pressure” is intended to include low latter movementwill pull cables 22 at each side airpressure such as a partial vacuum, as well as of the car toward eachother, thereby swinging to hydraulic pressure and positive high air pres- , armsk I5 on their pivots to move the _shoes I'II into engagement with` the wheels I, 2.» At the j same time, and proportional to the force applied sure above atmospheric pressure. Y Y , Having described my invention, I claim: ' l. In a wheelmounted vehicle including all; to the brakes, the ycables, 22 will pull the body 9V downwardly to'stabilize any pitching or rocking spring supported body carried by the wheels and of thebody, and also to somewhat compress the vbrakes for the latter, a ñuid 'pressure actuated v» springs 8'. mechanism including an element connected withY . This downward force also serves to increase they Vfrictionalr»resistance between the `70~ said brakes Vand movable in one direction under» wheels andthe rails to prevent ing of the brakes and wheels. ` skidding or lock- l « . From the standpoint of preferred structure*v r . the influence of lsaid fluid pressure for applyingk said brakes, a body depressing member connected ' with said body and with said element, means ' the cylinder ‘29 'shouid be -noatingiy s,m.~»por1;edsol ' mounting said member for downward movement that’th'e brakingfforce fromthaair or ñuid ¿inl 75 yupon said movement of said element in said one direction whereby'said member will pull down-«1 element under fluid pressureandim'eans connect-È _ wardly on said .body when said brakes are applied ing saidj brakes. and said'member to‘saidelen'ient'Y for somoving said brakesv and saidxmember. 6,;-5 In a railway car` having rail’engaging'wl‘reelsy supporting a frame .and springsv supporting .said bodyïon .said frame ;r brakeA shoes'respectively’ sup-. by actuation of saidy li'uid pressure> mechanism, saidk element being actuatable bysaid` fluid pres-`v surej for’ applying saidv brakes and: for so - moving said'. member independentlyI of “ .the torque. force transmit-ted'- to. said- brakes by said ‘wheels rwhen the latter are-rotatingand the brakes. are applied; ported on saidf'rame for movement.v into andzouti of: :frictional Vengagement with the peripheral '2, In a 'vehicle' having> front and rear. wheels, tread portions of said wheels, av body depressing axles for said wheels, brakes. for’ said rear wheels; 10 member secured to '.said body and extending. a'.- frame .carryingsaidaxles andY brakes, a body, downwardly therefrom, a` fluid pressure actuated and. springs yieldably supporting. saidlb‘ody -on element' movably supported. onv saidy frame andî saidîframe; as fluid pressure actuated mechanism- ~ v connected. with said vshoes and with said.v member' for.simultaneously- movingsaid shoes.' into en `carried byusaid frame for applying< said brakes, and. a movablel body depressing member con-J 15 gagement with said treadv portions and for movnested’ with' said fluid pressure mechanism. and ing saidl member downwardly upon actuation of'. said body»v` for Vpulling saidl body downwardly said element under fluid pressure, andmeanscon-ï against theresistance of usaid springs upon. actu necting said brakes` and said memberv to said ele-y ation of said mechanism for applying said brakes, ment for somoving said brakesand- said-member, said.. fluid pressure mechanism including an- ele 20 said lastmentioned means including an arm piv ment supported on said frame for` reciprocable otally supporting each of said brake'shoes-Lfor movement and said memberfbeing >connected with carrying the latter into kengagement withlsaid said element for movement therewith. treadV portions respectively upon pivoting eaclr » 3.. In a vehicle having front and rear wheels, arm, and a link connecting one end of said ‘a-rnr axles for said Wheels, brakes for said rear wheels, 25 to said element and to one end of said member. avframe carryingr said axles and brakes, a body, "1?. In. a railway car having rail engaging wheels? and springs yieldably supporting said body on supporting a frame and springs supporting said?y said frame; a fluid pressure actuated mechanism body on said frame; arms pivotally‘ supportedë carried byi said frame for applying said brakes, intermediate their ends on said frame atzpoints and` a movable body depressing member connect 30 adjacent said wheels; a brake shoe on one endî ed with saidi fluid* pressure mechanism and said of .each arm movable`4 into'» engagement. with the body forpulling said body downwardly against wheel` adjacent theretol upon swingingthe oppo-l the resistance of said springs upon actuation of site endof `each arm in» one direction.;l a> fluid pressaidA mechanism for applying said brakes, said sure actuated mechanism> connected ywith saidî huid pressure mechanismV including an element 35 opposite end of each arm for so swinging said`V supported on said frame for reciprooable move latter end,v anda link extending downwardly from ment and. said member being connected with said said body and- connected with said mechanism. element for movement therewith, said member andï witl'isaid opposite end of each arm adapted' being a flexible link secured at one of its ends to beurged downwardlyupon said swinging ofy~ to said element and secured at its opposite end 40 said oppositeend of said arm for depressing said to said body. ' ~ » 4A In a vehiclehaving front and rear wheels, bçdy against theA resistance of said springs simul taneously with application of said brakes. 8. In a' railway car having rail engaging wheels supportingr a frame and springs supporting said axles-for saidV wheels, brakesfor said rear wheels, a frame carrying said axles and-brakes, a body, and springs yieldably supporting said body on 45 bodyfon said frame; arms pivotally supported said- frame; means supporting said brakes for intermediate their ends on said frame at points generally oscillatory movement to and from wheel adjacent said wheels; a brake shoe onf one endl braking position; a fluid pressure actuated mem ber supported on said frame for generally recip rocatory movement connected with said means of each arm movable into engagement with> the wheelY adjacent thereto upon swinging the op and with said` body for simultaneously causing said oscillatory movement of said brakesV in one direction to said position and for drawing said body downwardly against the resistance of said springs upon application of fluid pressure to said member for actuating the latter, fluid pressure means connected with said member for so actu ating the latter, and means supporting said mem ber on said frame for downward movement of the posite end of each arm in one direction; said opposite end of each arm extending generally downwardlyl from the- pivot supporting the same; a pulley carried by each arm at its saidopposlte end; llexible links connected at one of their ends to said body and respectively extending down wardly therefrom and over each of said pulleys andrthen laterally-‘to fluid> actuated elements respectively movable under the influence of fluid pressure> for drawing said links against said portion thereof that is connected with said body 60 pulleys-whereby said' arms will be pivoted t0a ap when said member isactuated for causing appli ply the brakes and to simultaneously draw saidì cation of said brakes. body downwardly when said elements are so.. ac 5. In a railway car having rail engaging» wheels tuated, means securing said links 'to said ele supporting 'a frame and springs supporting said . ments, and fluid'` pressure means for so actu-v f l ' . body on said frame; brake shoes respectively sup 65. ating said elements. 9. In a vehicle having,l axlesV provided with portedv on said frame for movement' intoandfout of- fi’ictional engagement with theV peripheral body supportingwheels thereon, a body, and. tread portions- of said wheels, a body depressing member secured to said body and extending down springs supporting said body onî said axles; a frame carried 1by said axles; brake shoes carried' wardly therefrom, a fluid pressure actuated ele 70 on saidY frame adjacent' said wheels mounted` forv ment movably supported on said frame and con movement into and out of frictional engagement nected with said shoes and with said member for with the wheels; means securing said shoes. to said frame against movement together with said: simultaneously moving said'shoes into engage Wheels when said shoesiare in engagement there-A ment with said tread portions and' for moving said member downwardly upon actuation of said 75 with; a; body. depressing. element securedv to said 2,406,440 8 . body and adapted to >draw said body’ downward' ly against> the resistance'of 'said springs upon pressùreinto?said cylinderbetween'said head and î downward movement of said yelement;4 a member j -adjacent one of said adjacent pairs of Wheels said piston; means'connecting the brake shoes» securedgrto said brakes 'movable'in one direction' to said cylindenand' means Yconnecting the brake ` for applying said brakes to said wheels; apower 5 shoes YadjacentV thev other of said.` >adjacent Vpairs j actuated mem-ber connected to said, element and of wheels to saidÍpis'tonfrod for simultaneously Y applying said shoesl to said Íwheelsrwhen’ñuid is » l to said member arranged and adapted torsirnul Ítaneously move said element downwardly and admitted into said cylinder; thev said means re-‘ î to move said element in'Y said one direction vupon ï ‘ l application of power to»- said member. Spectively connecting said shoes to'said head and 10.111V a vemeieîhav'ing axles provided _with `body supportingpwheels Ythereon, a body, and springssupporting said` body on_ïsaid~ axles; a" to apply> said brakes whensaid rod and cylinder 1 said frame against movementtogether with said Wheels whensaideshoes are in engagement there rod and body for so moving said body.ï toisaid -piston rod being arranged .and adapted s are simultaneouslymoved oppositely', la iiexible connection. between` said body’and said piston ` frame carried by said raxles;lbrake shoes carried f rod actuatable -by'movement of said piston under on said frame adjacent said wheelsvmounted for 15, said fluid pressure for pulling> said body down : movement intoand out offrictional engagement ‘ wardly against the resistance of said> springs; means mounting said link relative to said piston îwith the Wheels; means securing said> shoes to ' - V13; A railway car comprising a spring lsup-=A ` with; a body, depressing element secured to said 20 ported body mounted on rail rengaging wheels and ' air operated brakes for said wheels including gen i body‘and-Vadapted to draw said body downward-_ ‘ " lyragainst they resistance of ~ said springs upon erally reciprocable air pressure actuated elements connected with said brakes; links extending downwardly- from said body and connected'to È'downwardvmovement of said element; a member , l secured‘to said Ibrakesmovable in one direction Á l for applying saidbrakes to said wheels; a power 25 said elements; means mounting said links'for downwardY movement upon reciprocation `of said elements under air pressure for applyingY` said Ybrakes whereby said body will be pulled down-Y s actuated member connected to said element and j l to said member arranged and adapted to simul- , taneously move said element downwardly andato move said element4 in said one direction upon ‘ applicationof power to said member, said brakes ; being carried on said frame adjacent the upper ` most portions of the tread surfaces of said wheels wardly upon applicationof said brakes. l Y 14. A railway car comprising a spring supe y ported body mounted on rail engaging wheels and airroperated brakes for said wheels including generally reciprocable air pressure Vactuated for movement into frictional engagement with `the generally Vupwardly facing parts of said ' membersl connected with said brakes; links ex l, tending downwardly from said‘body and oon l surfaces.’l 11.> Ina vehicle havinga pluralityof~ pairs of y axially aligned wheels, axles supporting said ` wheels, a body, and springs supporting said body Y ` on said axles; brake shoesl Vfor the wheelsof one l adjacent pair thereof supported on said frame Vlrfor movement finto' frictional engagementk with ` v nected to said elements; means _mounting said links for downward movement upon reciprocation of said elements under air pressure for applying said brakes whereby said body will »be pulled downwardlyr'upon application of said brakes, said links including flexible cables; and-_the means _; said wheels; a cylinder and a piston reciprocable mounting said links for said movement including ' Í thereon positioned Ybetween said adjacent pairs lof aligned >wheels;` said cylinderY having` a 4closed " pulleys over Ywhich said Vcablesrextend v’at points respectivelypositioned between said elements and head at one end, and a piston rod on said piston said body. ;-' ì. ' _, Y" e l projecting from’the opposite end of said cylinder; j ~ 15.~ -A »railway car comprising a spring supported `means Asupporting said cylinder for movement body mounted on rail engaging wheels: and air operated brakes forsaid wheels includingY gen-V f l thereof opposite to the direction of movement ï of said piston rod upon admission of fluid under l pressure into said cylinder between said head and ` said piston; means connecting the `brake shoes j adjacent one fof saidradjacent pairs oi wheels i to said cylinder, and means connecting the brake e ‘ shoes adjacent the other of said adjacentrpairs of wheels to said piston rod for simultaneously 1 applying said shoes to said Ywheels when ñuid z is admitted into said cylinder; the said means ; respectively connecting said'` shoes to said head erally reciprooable air pressure actuatedmem bers connected with said brakes; links extending downwardly from said body and connectedto said elements; means mounting said links for downward movement upon reciprocation of said elements under air pressure for applying saidV brakes whereby said body will be pulled down wardly upon application of said brakes, means at opposite ends of each car connecting said wheels to said body across the said springs for yieldably resisting relative movement of said body Íand to said piston rod `being arranged and l j adapted to apply said brakes when said rod and 60 and wheels apart while permitting relative move'-` ’ cylinder are simultaneously moved oppositely. 12. In a vehiclehaving ya plurality of pairs of *Y ment of said body and wheels toward each other upon compression of said springs. Y Y 16. In a vehicle 'having a spring supportedbody carried on pairs of,` opposed y body supporting l wheels, a body, and springs supporting said body on said axles; brake shoes for vthe Wheelspof one 65 wheels,l brakes for said wheels rrespectively sup"axially aligned wheels, axles Supporting ’ said l È adjacent pair thereof Ysupported fon-said frame `for movement into frictional engagement with § said wheels; a cylinder and a, piston reciprocable g thereon positioned between said adjacent pairs of ported adjacent each of said Wheels forgenerally oscillatory movement to Yand from >said wheels, generally reciprocably supported brakeactuating elements connected with said brakes for causing i aligned wheels; said cylinder'ghaving 3a closed w said movementgoi the'brakes upon reciprocation of said elements, a cylinder and piston recipro l head at one end, and a piston rod on said‘piston cable therein respectively connected to said‘brake i projecting from the opposite end of said cylinder; `means supporting said cylinder for movement > ' actuating> elements for said causing-reciproca tion ofV the latter upon reciprocating theV piston j thereof Vopposite to the direction of movement of j î said piston rod upon 'admission of‘riiuid under 75 andcylinder relatively bycausing huid pressure. 2,406,440 10 changes in the cylinder between one of its heads and said piston, means for causing such changes, and a stop member stationary relative t0 certain 0f said elements positioned to limit the move of the wheels to which said frictional resistance ' stop turning thereof and simultaneously there with pulling downwardly directly on said body against the resistance of the springs supporting the same, said step of pulling said body down wardly being free from the influence of the torque is applied, and varying the force of said down ward pull in direct proportion to the amount of frictional resistance so applied to said wheels. 19. The method of braking a vehicle of the type having body supporting wheels and a spring supported body carried by said wheels that com prises, applying a frictional resistance to the wheels to stop turning thereof and simultaneously therewith pulling downwardly directly on said body at both ends thereof against the resistance of the springs supporting the same, said step of pulling said body downwardly being free from the inñuence of the torque of the wheels to which said frictional resistance is applied. 20. The method of braking a vehicle of the type having body supporting wheels and a spring of the wheels to which said frictional resistance supported body carried by said wheels that com- ~ ment of the latter in one direction in the event of accidental disconnection of such certain ele-` ments with the brakes normally connected there with. ' 17. The method of braking a Vehicle of the type having body supporting wheels and a spring sup ported body carried by said wheels that comprises, applying a frictional resistance to the wheels to is applied. 18. The method of braking a vehicle of the type having body supp-orting wheels and a spring sup ported body carried by said wheels that comprises, applying a frictional resistance to the wheels to stop turning thereof and simultaneously there with pulling downwardly directly on said body against the resistance of the springs supporting the same, said step of pulling said body down wardly being free from the influence of the torque prises, applying a frictional resistance to the wheels at points above their axes of rotation re spectively to stop turning thereof and simultane ously therewith pulling downwardly directly on said body against the resistance of the springs supporting the same, said step of pulling said body downwardly being free from the influence of the torque of the wheels to which said frictiona] resistance is applied. ` CHRISTIAN H. SAUER.