US1927201A

US1927201A - Railway braking apparatus

Info

Publication number: US1927201A
Application number: US516883A
Authority: US
Inventors: Herbert L Bone
Original assignee: Union Switch and Signal Inc
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1931-02-19
Filing date: 1931-02-19
Publication date: 1933-09-19
Anticipated expiration: 1950-09-19
Also published as: FR734752A; FR43159E; GB391463A; DE597129C; FR44186E

Description

Sept. 19, 1933. H. BONE RAILWAY BRAKING APPARATUS Filed Feb. 19, 1931 mkfiwwmk w B N G mukmww an INVEN TOR.

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L M Q T g s QIY Patented Sept. 19, 1933 RAILWAY BRAKIN G APPARATUS Herbert L. Bone, Swissvalc, Pa, assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application February 19, 1931, Serial No. 516,883 32 Claims. (Cl. 188 -62) My invention relates to'railway braking apparatus, and particularly to apparatus of the type comprising braking bars located in the trackway and arranged to be moved at times into engagement'with the wheels of a railway car for retarding the speed of the car.

One object of my invention is to provide braking apparatus of the type described in which the movement of the braking bars into and out of engagement with the car wheels is effected by means of a plurality of self-contained, fluid pressure operated, interchangeable units so designed that the cost of maintenance and operation is reduced to a minimum.

In the accompanying drawing, Fig. l is a top plan view showing one form of braking apparatus embodying in invention. Fig. 2 is a vertical sectional view taken approximately on the line-IIII of Fig. 1. Fig. 3 is a left-hand side view of the apparatus shown in Fig. 2, with the fluid pressure motor M omitted to better illustrate the construction. Fig. 4 is a sectional view, showing on a somewhat larger scale, one of the centering units C forming part of the apparatus illustrated in Fig. 1.

Similar reference characters refer to similarparts in all four views.

Referring to the drawing, the reference characters l and 2 designate the track rails of a stretch of railway track, which track rails are mounted on rail supports 3. The rail supports 3, in turn, are each mounted on adjacent pairs of the usual crosstiesi, as best seen in Fig. 3, the supports being secured to the ties by means of spikes or lag screws 5. I

Extendingparallel to each track rail on opposite sides of the rail are two braking bars A and A each comprising a brake beam 6 provided with the usual wheel engaging shoe 7. As here shown,

each brake beam 6 is a'rail section of standard length, disposed on its side, andhaving its flange located adjacent the rail 1 or 2 in a position to properly support the brake shoe, but it will be readily understood that any other suitable type of brake beam may be employed.

The braking bars A and A are arranged to be loved toward or away from the associated track rail by means of a plurality of independent operating units, one of which may be associated with 1 each rail support 0. These operating unitsare all alike, a description of one will therefore suffice for all. As best seen in Figs. 2 and 3, the operating unit here shown comprises a lever 8 pivotally mounted at one end on a pivot pin 10 carried by the associated rail support 3 and a lever 9 pivotally mounted intermediate its ends on the pin 10. Thelever 8 is inclined upwardly and extends away from the rail 1, and is provided in its upper surface with a groove 8 which receives the braking bar A The one end 9 of the lever 9 is likewise inclined upwardly and extends away from the rail 1 at the opposite side of the rail from the lever 8, and the other end 9 of the lever 9 is inclined downwardly and extends away from the rail 1 belowthe lever 8. The end 9 of the lever 9 is provided in its upper surface with a groove 9, similar to the groove 8 in the lever 8, which groove receives the braking bar A As here shown, the braking bars are fastened to the levers by means of tap bolts 11 which pass through clearance holes in the web of the brake beams and are screwed into the levers. The parts are so arranged and so proportioned that if the outer or free ends of the levers are moved apart, the braking bars will be moved toward the rails into their efiectiveor braking positions. When the braking bars occupy their braking positions, the brake shoes '7 will engage the opposite side faces of the wheels of a car traversing the rails 1 and 2, and will retard the speed of the car, as explained more fully hereinafter. The center of gravity of the lever 8 and braking bar A is considerably to the left of the pivot pin 10, as will be seen from an inspection of Fig. 2, so that this lever will normally tend to rotate in a counter-clock- Wise direction about the pivotpin. Similarly, the center of gravity of the lever 9 and braking bar A is to the right of the pivot pin 10, as viewed in Fig. 2, so that this lever will normally tend to rotate in a clockwise direction about the pivot pin. It will be apparent, therefore, that when no force is applied to the free ends of the

levers

8 and 9 to move them apart, the free ends of the levers will move toward each other, thereby moving the braking bars to their open or ineffective positions in which they are illustrated in the drawmg.

Each operating unit also comprises suitable means for moving the levers apart. As here shown, this means is a fluid pressure motor M comprising a cylinder 12 containing a reciprocable piston 13 which drives a piston rod 14. The cylinder 12 is pivotally connected with the end 9' of the lever 9 by means of a pin 15, while an eyebolt l6 adjustably screwed into the upper end of the piston rod 14, and having its eye pivoted on a pin 17 carried by the lever 8, connects the piston rod 14 with the lever 8. A nut 18 is screwed on to the eyebolt 16 above the upper end or the piston rod to lock the eyebolt in its adjusted posiinto action as previously described.

apparent, therefore, that the braking force extion. Fluid pressure may be admitted to the cylinder 12 through an opening 19 which is threaded to receive a pipe 20. When fluid pressure is admitted to the cylinder, the piston 13 is forced upwardly, thereby separating the levers, and hence moving the braking bars toward their effective or braking positions.

Means are provided for supplying fluid pressure to the inotors M of all of the units simultaneously. As shown in Fig. 1, this means comprises a pipe 22 which is connected with the pipe of each of the motors M for the units which operate the braking bars associated with rail 1, and a pipe 23 which is similarly connected with the pipe as of each of the motors M for the units which operate the braking bars associated with rail 2. The pipes 22 and 23, in turn, are connected together by a pipe 21 which is at times supplied with fluid pressure from a suitable source not shown in the drawing through a pipe 24 and a valve mechanism V. The valve mechanism V forms no part of my present invention and its operating mechanism is therefore not shown in the drawing. One form of valve mechanism which may be employed for :this purpose is susceptible of control from a rcmote point, and comprising suitable means for regulating the pressure of the fluid which is sup plied to pipe 21, as well as means for completely cutting oil the supply of fluid pressure to the pipe 21, and for exhausting the pipe 21 to atmosphere.

The operation of the apparatus thus far described is as follows:

When fluid pressure is admitted to pipe 21 by -means of valve mechanism V, the piston 13 of the fluid pressure motor M of each operating unit is forced upwardly as previously described, thereby moving the braking bars toward their effective or braking positions. If there is a car in the brak- -ing apparatus when this happens, the braking bars will engage both sides of the wheels of the car before the pistons reach the extreme upper end of their strokes, and the full force of the fluid pressure will therefore be transmitted to qj the braking oars through

levers

8 and 9. It will be apparent, therefore. that under these conditions the braking bars will exert braking force on the car which proportional to the product of the pressure of the fluid supplied to the motors ;multiplied by the ratio of the levers. If, however,

there is no car in the apparatus when fluid pressure is supplied to pipe 21, the pistons 13 of the fluid pressure motors will move to the upper end of their strokes, and the braking bars will theregfore be moved to their full braking positions.

Under these conditions, ii a car enters the oral:- ing apparatus, the braking bars will be forced away from the rails, thereby bringing the pressure of the fluid in the cylinders of the motors It will be erted by the braking bars may be varied to any desired value by varying the pressure of the fluid supplied to the fluid pressure motors. It will also ;be apparent that when the braking bars are engaging the whecls of the car, the reaction of the wheels is cushioned against the volume of fluid in the cylinders 12 of the motors M.

If, after the braking bars have been moved to their braking positions, the supply of fluid pressure to the pipe 21, and hence to the fluid pressure motors M, is subsequently cut off, the pipe 21 is then vented to atmosphere, the braking bars will return by gravity to their ineffective positions in which they are illustrated in the drawing for the reasons pointed out hereinbefore, it being understood that the weight of the braking bar A is sufiicient to overcome the counterbalancing effect of the cylinders 12 of the motors M which are connected with the lovers 9.

It should be pointed out that due to the shape and arrangement of the

levers

8 and 9 already described, and to the positions in which the braking bars are mounted on the levers, the braking bars are raised as they are moved toward the rails. This causes the braking bars to engage the car wheels at a higher position, and therefore a more effective braking position, than would be the case ii this raising or tipping of the braking bars did not take place. Furthermore, since the braking bars are raised as they are moved toward their braking positions, greater clearances may be obtained between the braking bars and the wheels of cars or locomotives when the braking bars occupy their non braking positions than would otherwise be possible if this raising did not take place. i

It should also be pointed out that since the

evers

8 and 9 and the fluid pressure motor M of each operating unit are free to rotate about the associated pivot pin 19 as a unit, the brake shoeswill adjust themselves to thecar, wheels in such manner that the pressure on both sides of the wheels will'be equalized.

It will be readily understood that it is desirable to have the braking bars centered when they are in their open or inefiective positions, in order to insure that the brake shoes will not engage the wheels of cars or locomotives passing through thebraking apparatus which should not be retarded, and it is also desirable to have them centered when in their eflective or braking positions, so that cars which are to be retarded may enter the braking apparatus smoothly. Inasmuch as the operating units are free to rotate about the pivot pins 10 in the manner previously described, it is necessary to provide some means for accomplishing this desirable result, and for this purpose, I employ a plurality of centering units C, one of which, as here shown, is associated with each of the four end operating units as illustrated in Fig. 1. These centering units are all similar, and a description of one will suffice for all. Referring to Figs. 2 and 4, the centering unit C here shown comprises a tube 25. which is supported in a vertical position by means of an arm 44 attached to an adjacent rail support 3. The lower end of the tube 25 is partially closed by an integral end plate 26 having a centrally located hole 2'7, and the upperend. of this tube is also partially'closed by an end plate 28, which is screwed into the tube, and which is provided with a centrally located hole 29. Located within the tube 25 is a coil spring 42. Interposed between the upper end of this spring and the end plate 28 is a member 30 provided with a centrally locatedhole 31, and interposed between the lower end of the spring 42 and the end plate 26 is a A rod 34 extends with clearance through the holes 31 and 33' in the members 30 and 32, and is provided with an abutment. 35 which normally enters the hole 2'7 in the end plate 26 and engages the lower side of the member 32. Screwed onto theupper end of the rod 34 is a nut 36 which enters the hole 29 in the end plate 28 and normally engages the upper side of the member 30. Also screwed onto the upper end of the rod 34 in an adjusted vertical position is a stop member 43 which cooperates with a lug 8 formed on the lever 8 as best seen in Figs- 2 and 3. This stop member is locked in its adjusted position by means of a jam nut 37 which is screwed against the lower end of the stop member. A second stop member 38 is. likewise adjustably screwed onto the lower end of the rod 34, and this stop member is formed with a rectangular opening which receives with considerable clearance a pin 40 which projects from the side of the lever 9. The stop member 38 is locked in its adjusted position by means of a jam nut 41.

With the centering units constructed in the manner just described, when pipe 21 is vented to atmosphere to permit the braking bars to move to their ,ineiiective or non-braking positions, the lever 8 of each operating unit will rotate about the associated pivot pin 10 in a counter-clockwise direction in the manner previously described until the lugs 8 on the levers or" the four end operating units each move into engagement with the upper stop member 43 of the associated centering unit as shown in Fig. 2, and the lever 9 of each operating unit will rotate about the associated pivot pin .10 in a clockwise direction until the pins 40 carried by the levers 9 of the four end operating units each move into engagement with the lower stop-member 38 of the associated centering unit at the upper edge of the opening 39 in this member, after which further rotation of the levers of the end operating units is prevented by the associated rod 34 as will be apparent from an inspection of the drawing. The stiffness of the spring 42 of each centering unit is such that this spring will. hold the associated rod 34 in the position shown in Figs. 2 and 4 under the above conditions, and the

stop members

43 and 38 are so adjusted that when the levers are engaging the stop members in the manner just described, the braking bars A and A will each be spaced away from the rails" the desired amount.

When, however, fluid pressure is supplied to pipe 21 to move the braking bars to their effective or braking positions, the levers 9 of the operating units will all move downwardly until the pins 40 carried by the levers 9 of the four end operating units each engage the lower stop member 38 of the associated centering unit at the bottom of the opening 39, after which the'levers 8 of the operating units will all be moved upwardly by the pistons 13 of the fluid pressure motors M as pre-' viously described. The parts are so proportioned that if there is no car in the brakin'gapparatus,

under these conditions, so that the pistons 13 can move to the upper end of their strokes, the braking bars A and A will then each occupy the desired relative position with respect to the rails.

It should be pointed out that if, during the passage of a car through the braking apparatus, it is necessary, in order to permit the brake shoes to adjust themselves to the car wheels, that the operating units rotate about the pivot pins 10 to such a position that one or the other of the

levers

8 or 9 of the end units engages the cooperating stop member of the associated stop units, the

springs 42 of the centering units will deflect a sufficient amount to permit the necessary movement of the braking bars.

One advantage of braking apparatus embodying my invention is that the operating mechanism is composed of a series of interchangeable units, each of which consists .of relatively few parts all readily accessible for inspection or repair. The stresses in each unit are self-contained and there are relatively few bearings which require lubri-- cation and replacement.

Another advantageof braking apparatus embodying my invention is that the brake beams which support the brake shoes are continuous throughout the length of the retarder, thus permittingthe cars to pass through the retarder without jars or shocks which might tend to derail the car or impose excessive strains on the brain ingapparatus.

Another advantage of braking apparatus embodying invention is that since the fluid pressure motors of the operating units are connected directly with the operating levers, the reactionof the wheels on the braking is cushioned against the volume of fluid in the cylinders, thereby eliminating the necessity for springs or other cushioning devices sometimes provided in braking apparatus of the general type here considered. Furthermore, the pressure of the brake shoes against the car wheels may be varied by varying the pressure of the fluid supplied to the fluid pressure motors, and this variation in pro"- sure is obtained without the movement of any parts. In addition, the fluid pressure supplied to the motors may be either increased or decreased to increase or decrease the braking force while the'apparatus is occupied by a car and the full effect of the change in pressure on the retardation is immediately effective.

Another advantage of braking apparatus embodying my invention is that when the braking bars are engaging acar wheel, full equalization of pressure on both sides of the car wheel is obtained.

Still another advantage of braking apparatus embodying my invention is that the braking bars will return to their open or ineffective positions by gravity. The lost motion which might deeiop due towear is therefore always taken up so as to keep the distance between the brake shoes at its maximum. There is therefore no lost motion to be taken up as the car enters the apparatus and the lost motion accordingly can not increase the shock. This'self-opening feature also provides the full brake shoe opening for which the braking apparatus is designed, at its open position, regardless of the lost motion which may have occurred due to worn parts.

A further advantage of braking appar t 71;

bodying my invention is that the usual track circuits commonly employed for railway signaling purposes may be extended through the braking apparatus in the usual manner, and will be reliable even if a car is raised on the brake shoes.

. in the Well known forms of car retarders. If this type of construction were used, the brake beams would be articulated, and would be supported at each of the pneumatic operating units.

Although I have herein shown and described only one 'form of railway braking apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims wtihout departing from the'spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway braking apparatus comprising'two braking bars located on opposite sides of a track rail and adapted to be moved toward the rail into engagement with thewheels of a car for retarding the speed of the car, two levers one for supporting each of said braking bars, said levers being pivoted about a common axis in such manner that movement of said levers will move said braking bars toward or away from said track rail, a fluid pressure motor having a cylinder which is pivotally connected directly with one of said levers, and a piston in said cylinder driving a piston rod which is pivotally connected directly with the other one of said levers.

2. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and adapted to be moved toward and away from the track rail into braking and non-braking positions, two levers one for supporting each of said braking bars, said levers being pivotally mounted for rotation about a common axis in such manner that said braking bars are biased by gravity to their non-braking positions, a fluid pressure motor having a cylinder pivotally connected with one lever, and a piston in said cylinder provided with a piston rod which is pivotally connected with the other lever in such manner that when said piston is moved to one end of its stroke said levers are operated to move said braking bars to their braking positions.

Railway braking apparatus comprising two braking bars located on opposite sides of a track rail, a first lever for supporting one of said braking bars, said first lever being pivotally mounted at one end and having its free end inclined upwardly and extending away from said track rail, a second lever pivotally mounted intermediate its ends and having one end inclined upwardly on the opposite side of the rail from said first lever for supporting the other braking bar and having its other end inclined downwardly and extending away from the rail below the free end of said first lever, and a fiuid pressure motor for moving said free end of said first lever and said other end of said. second lever apart.

4. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail, a first lever for supporting one of said braking bars, first lever being pivotally mounted at one end and having its'free end inclined upwardly and extending away from said track rail, a second lever pivotally mounted intermediate its ends and having one end inclined upwardly on the oppositeside of the rail from said first lever for supporting the other braking bar and having its other end inclined downwardly and extending away from the rail below the free end of said first lever, a fiuid pressure motor connected between the free end of said first lever and said other end or" said second lever and supported solely by said levers for moving said levers apart.

5. Railway braking apparatus comprising two braking bars located on opposite sides of a track a first lever for supporting one of said braking bars, said first lever being pivotally mounted at one end and having its free end inclined upwardly and extending away from said track rail, a second lever pivotally mounted intermediate its ends and having one end inclined upwardly on the opposite side of the rail from said first lever for supporting the other braking bar and having its other end inclined downwardly and extending away from the rail below the free end of said first lever, a fiuid pressure motor having a cylinder which is pivotally connected directly with said other end of said second lever, and a piston in said cylinder provided with a piston rod which is pivotally connected directly with the free end of said first lever. 1

6. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and adapted to be moved toward and away from the track rail into braking and non-braking positions, a first lever for supporting one of said braking bars, said first lever being pivotally mounted at one end and having its free end inclined upwardly and extending away from said track rail, a second lever pivotally mounted intermediate its ends and having one end inclined upwardly on the opposite side of the rail from said first lever for supporting the other braking bar and having its other end inclined downwardly and extending away from the rail below the free endof said first lever, the parts being so proportioned that said levers are biased by gravity to the positions in which said braking-bars ccupy non-braking positions, and a fluid pressaid lever being inclined upwardly and extend-' ing away from the rail, a second lever pivotally mounted intermediate its ends on said pivot pin and having one arm extending upwardly and away from the rail on the opposite side of the rail from said. first lever to support the other braking bar and having its other arm extending downwardly and away from the rail below said first lever, the parts being so proportioned that said braking bars are biased by gravity to their nonbraking positions, a fiuid pressure motor having a cylinder pivotally connected with and supported by said other end of said second lever, a piston in said cylinder provided with a piston rod, and an adjustable eyebolt screwed into the free end of said piston rod and having its eye pivotally connected with the free end of said firstlever.

3. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and adapted to beinoved toward the rail into engagement with the wheelsof ,a car for retarding the speed of the car, two levers one for supporting each of said braking bars, said levers being pivoted about a common axis in such manner that movement of said levers will move said braking bars toward or away from said track rail, the parts being so proportioned that said levers are biased by gravity to the positions in which said braking bars are moved away from said track rail, a fluid pressure motor for moving said levers to the positions in which said braking bars are moved toward said track rail, and means associated with said levers for maintaining said levers in predetermined relative positions except when said braking bars are engaging a car wheel.

9. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and adapted to be moved toward the rail into engagement with the wheels of a car for retarding the speed of the car, two levers one for supporting each of said braking bars, said levers being pivoted about-a common axis in such manner that movement of said levers will move said braking bars toward or away from said track rail, the parts being so proportioned that said levers are biased bygravity to the'positions in which said braking bars are moved away from said track rail, a fluid pressure motor for moving said levers to the positions in which said braking bars are moved toward said track rail, a lug on one of said levers and a pin carried by the other lever, and means cooperating with said pin and said lug for normally maintaining said levers in predetermined relative positions.

I 10. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and adapted to be moved toward the rail into engagement with the wheels of a car for retarding the speed of the car, two levers one for supporting each of said braking bars, said levers being pivoted about a common axis in such manner that movement of said levers will move said braking bars toward or away from said track rail,'the parts being 'so proportioned that said levers are biased by'gravity to the positions in which said braking bars are moved away from said track'rai-l, a fluid pressure motor for moving said levers to the positions in which said braking bars are moved toward said track rail,

a lug on one of said levers and a pin carried by.

the'other lever, and yieldable means cooperating with said pin and said lugfor normally maintain ing said levers in predetermined relative posie tions.

11. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail and adapted to be moved toward the rail into engagement with the wheels of a car for retardingthe speed of the car, t'wo levers one for supporting each of said braking bars, said levers being pivoted about a commoniaxis in such manner that movement of said levers will move said braking bars toward or away from said track rail, the parts being so proportioned that said levers are biased by gravity to the positions in which said braking bars are moved away from said track rail, afluid' pressure motor for moving said levers to the positions in which said braking bars are moved toward said track rail,

-- a lug on one of said levers and a pin carried by the other lever, a rod biased to' one position by means of a spring, an adjustable stop on one end of said rod adapted to cooperate with said lugto limit movement of said one lever in the direction which moves the associated braking bar away from the track rail, and an adjustable stop member on the other end of said rod provided with an opening which receives said pin with considerable clearance, said'stop members being so adjusted that said braking, bars are normally maintained in predetermined positions with respect to said rail in both their open and closed positions.

12. Railway braking apparatus comprising two braking bars located on opposite sides ofa track rail and adapted to be moved toward and away from the track rail into braking and non-braking positions, a first lever for supporting one of said braking bars, said first lever being pivotally mounted at one end on a fixed pivot pin and having its'free end inclined upwardly and extending away from said rail, a second lever pivotally mounted intermediate its ends on said pivot pin and having one end inclined upwardly and extending away from said rail in a position to support the other braking bar and having its other end inclined downwardly and extending away from the rail below the free end of said first lever, the parts being so'proportioned that said braking bars are biased to their non-braking positions by gravity, a fixed tube mounted in a vertical position adjacent said levers, said tube having its'ends partly closed by end plates provided with centrally disposed openings, a coil spring. in said tube, a first member provided with a centrally disposed hole interposed between one end of said spring and one end plate and a second member provided with a centrally disposed hole interposed between the other end of said spring and the other end plate, a rod extending through the holes in said two members and provided with an abutment adapted to engage the outer side of one member, a nut screwed on said rod and adapted to engage the outer side of the other member, whereby movement of said rod in either direction is opposed by said spring, a first stop member screwed on one end of said rod, a lug on said first lever adapted to engage said-first stop member for at times limiting the downward movement of said first lever, a second stop member screwed on the other end of said rod 73 ous brake beam and a brake shoe attached to said brake beam, and a plurality of similar fluid pressure controlled operating units for moving said braking bars toward and away from the track rail into braking and non-braking positions; each said operating unit comprising two levers for supporting said braking bars, said levers being pivotally-mounted for rotation about a common axis, a fluidpressure' motor having a cylinder pivotallyf connected directly with one lever, and a piston in said cylinder operatively connected with the other lever.

- 14. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail, each said braking bar comprising a continuous brake beam and abrake shoe attached to said brake beam and a plurality of similar fluid pressure controlled operating units for moving said braking bars toward and away from the track rail into braking and non-braking positions;

each said operating unit comprising a first lever for supporting one of said braking bar s, said first lever being pivotally mounted at one end and having its free end inclined upwardly and extending away from the track rail, a second lever pivotally mounted intermediate its ends and 1 15'. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail, two levers pivotally mounted for rotation abouta common axis and supportingsaid two braking bars respectively, and a fluid pressure motor entirely supported by said levers and involving a cylinder pivotally connected with one lever and a piston pivotally connected with the other lever.

16. Railway braking apparatus comprising two braking bars located on opposite sides of a track rail, two pivoted levers supporting said two braking bars respectively, a fluid pressure motor supported entirely by said levers for operating the leversto move said braking bars towardthe track rail, a lug on one of said levers and a pin carried by the other lever, and means co-operating with said pin and said lug for normally maintaining said levers in predetermined relative positions.

17-. Railway braking apparatus comprising two levers pivoted beneath a track rail, the first lever being pivoted at one end and the second being pivoted at an intermediate point, a braking bar supported at an intermediatepoint on the first lever and located on one side of the track rail, a second braking bar supported by one end of the second lever and located onthe other side of the track rail, said parts being so arranged that when the other ends of the levers are moved apart both braking bars are moved toward the rail, and a fluid. pressure motor entirely supported by said levers for moving the last-mentioned ends apart and comprising a cylinder pivotally connected with one lever and a pistOnoperating in said cylinder and pivotally connected with the other lever.

18. Railway braking apparatus comprising two levers of the first and second classes respectively, fulcrumed at 'a common point beneath a track rail and having their power arms extending in thesame direction from the rail with the power, arm for the first class lever disposed below the power arm for the second class lever, two braking bars located on opposite sides of the rail and constituting the loads for said two levers respectively, and a fluid pressure motor supported entirely by said levers and involving a cylinder connected with the power arm of the first class lever and a piston operating therein and connected with the power arm of the second class lever.

19. In combination, a rail support, a track rail mounted on said support, two braking bars located on opposite sides of said track rail, two levers pivotally mounted in said support and supporting said two braking bars respectively, and a fluid pressure motor entirely supported by said levers for operating the levers to move said braking bars toward the track rail.

. 20. In combination, a pluralityoi spaced rail supports, a track rail mounted. on said supports, a plurality of operating devices one associated with each support and each involving two levers pivotally mounted in the associated support, two braking bars located on opposite sides of said track rail and supported entirely by said levers, each device also involving a fluid pressure motor supported entirely by the associated levers for operating such levers to move said braking bars toward the track rail.

,21. In combination, a plurality of spaced rail supports, a track railmounted on said supports, a plurality of operating devices one associated with each support and each involving two levers pivotally mounted in the associated support, two braking bars located on opposite sides of said track rail and supported entirely by said levers, each device also involving a fluid pressure motor supported entirely by the associated levers for 22. In combination a plurality of spaced rail supports each mounted on an adjacent pairof the usual ties and each spanning the space between the associated ties, a track rail mounted on said supports, a plurality of operating devices one associated with each support'and each involving two levers pivotally mounted in the associated support, two braking bars located on opposite sides of said track rail and supported entirely by said levers, each device also involving afiuid pressure motor supported entirely by the associated levers for operating such levers to move said braking bars toward the track rail, r

23. In combination, a rail support, a track rail mounted on said support, two brakingbars lo cated on opposite sides of said track rail, two levers pivotally mounted in said support for rotation about a common axis and supporting said two braking bars respectively, and a fluid pressure motor entirely supported by said levers and involving a cylinder pivotally connectedwith one lever and a piston pivotally counected with the other lever. v

'24. In combination, a rail support, a track rail mounted on said support, two braking bars located on opposite sides of said track rail, a first lever pivotally mounted in said supportand having a part extending upwardly on one side of the track rail and supporting one of said brakingbars and another part extending away from said track railat the opposite side'of the rail from said one part, a second lever pivotallyvmounted in said support and having one part extending upwardly on the same side of said track rail as said' other part of said first lever and supporting the other braking bar, said second lever alsohaving another part extending away from the track. rail substantially invertical alignment with said other part of said first lever, and a fluid pressure motor mounted between and supported entirely by said other parts of said levers for operating said lovers to move said braking bars toward the track rail. 25. In combination, a rail support, a track rail mounted'on said support, two braking bars 10 cated on opposite sides of said track rail, two levers pivotally mounted in said support and entirely supporting said two braking bars respectively, and a fluid pressure motor for o'peratingthe levers to move said braking bars'toward the track rail, said motor being entirely supported by the levers and having itsaxis substantially vertical.

26. Railway braking apparatus comprising in combination with a track rail, two substantially horizontal levers each pivoted beneath the track rail, two braking bars attached to said two levers. respectively and both movable toward the track rail in response to movement of said levels in opposite directions about their pivots, and a fluid pressure motor supported entirely by the levers with its axis in a substantially vertical line for applying forceto the levers to move the levers in opposite directions about their pivots. v

27. Railway braking apparatus comprising in combination with a track rail, two substantially horizontal levers each pivotedbeneath the track rail, two braking bars attached to said two levers respectively and both movable towardthe track rail in response to movement of said levers in op posite directions about their pivots, and asfluid pressuremotor comprising a cylinder and a piston connected respectively with said two-levers at V points in a substantially vertical line, said motor driving said levers in opposite directions about their pivots.

28. Railway braking apparatus comprising in combination with a track rail, two substantially horizontal levers each pivoted beneath the track rail, two braking bars attached to said two levers respectively and both movable toward the track rail in response to movement of said levers in opposite directions about their pivots, and a motor for applying force to the levers in a substantially,

vertical line to drive the levers in opposite directions about their pivots, said motor being disposed wholly above the ground and being supported entirely by the levers.

29. Railway braking apparatus comprising in combination with a track rail, two levers each pivoted beneath the track rail and each-comprising a substantially vertical arm and a substantially horizontal arm, two braking bars located on opposite sides of the track rail and supported entirely by the vertical arms of said two levers respectively, and a motor connected with the horizontal arms of said two levers for applying a force to said levers in a substantially vertical line to operate said levers to move said braking bars toward the track rail.

30. Railway braking apparatus comprising in combination with a track rail, two braking bars located on opposite sides of the track rail, two levers each pivoted beneath the track rail and each carrying one of said braking bars, and a motor located above the ground and supported entirely by said levers for operating said levers to move said braking bars toward the track rail.

31. Railway braking apparatus comprising in combination with a track rail, two braking bars located on opposite sides of the track rail, two levers each pivoted beneath the track rail and each carrying one of said braking bars, and a motor located substantially in the horizontal plane of the track rail and supported entirely by said levers for operating said levers to move said braking bars toward the track rail.

32. Railway braking apparatus comprising in combination with a track rail, two braking bars located on opposite sides of the track rail, two levers each pivoted beneath the track rail and each carrying one of said braking bars, and a motor for operating said levers to move said braking bars toward the track rail, said motor being located wholly above the ground and being supported'entirely by the levers and having its axis disposed substantially vertically.

HERBERT L. BONE.