US3196985A

US3196985A - Railway braking apparatus

Info

Publication number: US3196985A
Application number: US251818A
Authority: US
Inventors: Rowe Gerwyn Trevelyan; Whittard Gerald Albert; Melhuish Arthur William
Original assignee: Westinghouse Brake and Signal Co Ltd
Current assignee: Siemens Mobility Ltd
Priority date: 1962-01-24
Filing date: 1963-01-16
Publication date: 1965-07-27
Anticipated expiration: 1982-07-27
Also published as: GB971473A

Description

July 27, 1965 G. T. RowE ETAL RAILWAY BRAKING APPARATUS.

Filed Jan. 16, 1965 United States Patent O 3,196,985 RAHJWAY BNG APPARATUS Gerwyn Trevelyan Rowe, Geraid Albert Whittard, and Arthur William Melhuish, London, England, assignors to Westinghouse Brake and Signal Company, Limited, London, England Filed lan. 16, 1963, Ser. No. 251,818 Claims priority, application Great Britain, dan. 24, 1962, 2,644/ 62 Claims. (Cl. 13S-62) Our invention relates to railway braking apparatus, and particularly to braking apparatus of the type comprising wheel engaging braking bars extending parallel to the rails of a railway track and movable upwardly toward and downwardly away from the rails into braking and nonbraking positions. More particularly, our invention relates to improvements in apparatus of the type described in which the braking bars are arranged to be moved to their braking positions by means of a fluid pressure operated motor or motors, and to be restored to their nonbraking positions by suitable biasing means such as gravity.

The present invention relates to power braking apparatus of the type which may be used as hump car retarders located on the entrance track a short distance ol the hump or other car retarders, commonly known as group car retarders, which are located at various points in approach to classification tracks to control the speed of rolling cars as they approach their destinations in the various classification tracks of a car classification yard. As in most car retarders of the track brake tppe, brake beams are disposed end to end at both sides of the track rail, and an operating unit is provided at each point where the ends of the brake beams are adjoining `and also at each extreme end of the car retarder. The operating -units may be disposed in the conventional manner between two of the cross ties and spaced, for example, every third tie. Further, the braking apparatus can be larranged as either a singleV or double-rail retarder and made to any desired length. In addition, the entire braking apparatus is universal i-n application; that is, the operating units, which are simple self-contained interchangeable units, the remaining parts and even the complete retarder assembly may be applied by either a right-hand or lefthand rail without change.

As is well established, the most effective braking in a track type car wheel braking apparatus occurs when the braking force is applied at a relatively high point on the sides of the car wheels. Further, as is well known, it is advantageous to position the braking bars relatively low with respect to the track rail and also to open the braking bars relative to each other as much as possible during nonbraking conditions. ln the past, various schemes and arrangements have been designed for accomplishing the above-mentioned advantageous features. For example', Letters Patent of the United States No. 1,868,493, granted to H. C. Clausen, on July 26, 1932, illustrates and describes a two point fulcrum arrangement for raising and lowering the braking bars as they move from a braking to a non-braking position, while the Letters Patent of the United States No. 2,089,823, granted to H. L. Bone, on

August l0, 1937, illustrates and describes a link arrange- Patented July 27, 1965 a novel and improved railway braking apparatus of the type described y Another object of our invention is the provision of a novel lever pivotal arrangement which permits the braking bars to rest lower relative to the rail and to open wider relative to each other during nonbraking conditions so that damage to the braking apparatus due to railway vehicle carried equipment is considerably lessened.

Another object of our invention is the provision of a railway braking apparatus having a novel three point pivotal lever arrangement which permits a greater degree of braking bar lifting than heretofore possible.

We will describe one form of railway braking apparatus embodying our invention, and will then point out the novel features thereof in the appended claims.

Other objects and advantages of our invention will become apparent from a consideration of the following detailed description, taken in connection with the accompanying drawings where:

FIG. l is a plan view showing an operating unit for the braking apparatus embodying our invention.

FIG.- 2 is a vertical sectional view taken substantially along the line Il-llof FIG. 1.

FIG. 3 is a fragmentary topplan viewv showing one form of the braking apparatus embodying our invention.

Generally, the objects of our invention are achieved by providing a railway braking apparatus or car retarder having braking bars which Vare moved into and out of engagement with Vwheels of a railway car for controlling the speed thereof. Each braking bar extends parallel to the track rail and consists of a plurality of brake beams, secured together bymeans of replaceable brake shoes. The braking bars are adapted to move relative to the track rail into braking and non-braking positions, andfor this purpose a plurality of independent operating units are preselectively spaced at regular intervals along the parallel extending-braking bars. Each of the operating units is alike and consists of a pair of levers uidly actuated for pivital movement Vabout a common fulcrum. This pivotal movement about the common fulcrum causes the braking bars carried by the levers to move toward and away from each other as the iiuid actuated motor attached `to thelever arms is energized and deenergized, respectively. A second fulcrum located vat the end remote from the actuating motor pivotally supports one of the levers for relative rotation thereabout. A third fulcrum located intermediate kthe ends of the other lever pivotally supports it for relative rotation thereabout. The-third fulcrurn is arranged as a -pivot point and a rol-ler bearing assembly so that a rotational and a lateral movement is imparted to the latter lever. Upon application of fluid pressure to the viiuid actuating motorV the braking bars undergo an elevating and a closing movement due tothe lever supporting fulcrum arrangement, and then upon Iventing of the fluid motor to the atmosphere gravity acts to lower and open the braking bars to their normal retracted position.

Referring to Ithe drawings, the reference character 15 designates one track rail of a stretch of railway, which track rail may be mounted and secured to conventional rail supports fastened to cross-ties inthe usual and well'- known manner. Extending parallel to the rail 15 on opposite sides of the'rail are two braking bars 10a and ltlb, each braking bar comprising a plurality of brake beams 11 disposed end-to-end and secured together by means of replaceable brake shoes 14. As shown in FIG. 3, a plurality of similar operating units is spaced at predetermined intervals along the braking bars and is adapted to move the braking bars toward and away from rail 1S into braking and nonbraking positions.

With reference to the drawings, and particularly to 3 FIGS. 2 and 3, it is noted that a single operating unit is illustrated, this being yfor the sake of simplicity since all the operating units are identical and a description of one will therefore suice for all. VThis `operating unit comprisesA an upper bifurcated lever 1 and a lower lever 3 positioned between the bifurcations of lever 1. A pivot pin 4 cooperates with reinforced bea-ring apertures located intermediate the ends of both levers to rotatably support these levers in pivotal relation to each other. vThe leverr 1 is inclined upwardly and extends away from the rail 15, and is provided adjacent the rail with a flat .surface 1a which supports the braking bar 10a. The other bifurcated end 1b of lever 1 is rotatably mounted about a fulcrum in the form of stationary journal support assembly 2a having shafts 2 and which may be securely fastened to convenient bearing plates V2b mounted on adjacent pairs of crosstes. The one end 3a of lever 3 'is likewise inclined upwardly and extends away from rail 15 at the opposite side of the rail from the bifurcated arms of lever 1, and the other end 3b of the lever 3 is inclined downwardly and extends away from the rail 15 below the bifurcated'arms of lever 1. The end 3a of ,fthe lever 3V is provided adjacent the rail with a at surface 3c, similar to the surface 1a, for supporting the braking bar b. Ashere shown, the Itwo braking bars V10a and 10b are fastened toY the levers in an identical manner, and therefore a description of one is believed suflicient for a clear understanding thereof. Referring to braking bar 10b, the brake beams 11 are all alike ,and each brake beam spans the space between two adjacent operating units and is disposed with its opposite ends resting on the flat surface portions 3c of the lever 3 of adjacent operating units in such a manner that the beam is free to slide toward and away from the rail on these surfaces. Provided on each end of each beam at the farthest side from the rail is a retracting lug 11a. The two lugs 11a on the confronting ends of adjacent beams hookaround the ends of thrust block 13 to position the Abrake beams inl proper braking position laterlally with respect to the rail. Vertical movement of the Vbrake beam 11 with respect to the associated lever at the edge nearest the rail is limited to a predetermined amount by integrally formed hold-down lugs 11b provided on each end of each adjacent brake beam 11. These hold-down lugs 11b cooperate with outwardly extending lever lugs formed on dat surface 3c of the lever 3 Vto limit vertical movement of the braking bar 10b. Each thrust block 13 is xedly secured to the levers by suitable mounting bolts and shims may be disposed onthe thrust block mounting bolts to provide a lateral Vadjustment for compensating for brake shoeV wear. An additionalfulcrum in the form of a roller bearing 5 is located intermediate the common fulcrum pin 4 and end 3 b of lever 3 lwhich fulcrum cooperates with a bearing plate 6 suitably mounted to adjacent pairs of crosstes for pivotally, supporting the lever 3. 'I'his roller bearing andbearing Aplate arrangement permits the lever 3 to rotate as well as'move laterally with respect to the rail 15 in a manner which will be described in detail hereinafter. Y

YThe parts are so arranged and so proportioned that when the'outer or free ends of the levers 1 and 3 are moved apart, the braking bars will be moved upwardly and toward the rail to the effective or braking position in'which the brakeshoes 14 assume positions partially shown by the dashedV lines in FIG. V2, whereby they will engage the opposite sides ofthe wheel of.a car traversing Vrail. 15 and will retard the speed of the car. The center of gravity'pof the lever 1 and the braking bar 10a is considerably to the left of pivot pin 4, as seen from an inspection of FIG. `2, so that this lever will normallytend to swing in Ya counterclockwise direction relative to pivot pin 4. Similarly, the center of gravity of the lever 3 and braking bar 10b is to the right of pivot pin 4, as viewed in FIG. .2, so that this lever will normally tend to swing in a clockwise direction relative to pivot pin 4. It will be apparent, therefore, that when no force is applied to lthe free ends of the levers 1 and 3 to move them apart, the free ends of the levers will move toward each other, thereby moving the braking bars downwardly and away from the rail to their open or ineffective position as shown in FIG. 2.

The levers 1 and 3 are arranged to be moved apart by means of a conventional uid pressure motor 7 comprising a cylinder 7a containing a piston 7b with'an attached piston rod 7c. The cylinder 7a is pivotally connected with the free bifurcated end of lever 1 by means of a pivot pin 9, while the piston rod 7c is connected at its free end with the free end 3b of lever 3 by means of a pivot pin 8. Y

Fluid pressure may be admitted to the cylinder 7a through an opening which is threaded `to receive pipe 16. In operation, when fluid pressure is admitted to the cylinder, a downward force is exerted on the piston 7b and an upward force is exerted on the cylinder, thereby separating the arms of the levers 1 and 3. As the arms of :the levers 1 and 3 move apart, each lever swings independently about its separate fulcrum and rotates relative to one another about the common pivot pin or fu1 crum. That is, as the lever arms separate, lever 1 swings in a clockwise direction about journal 2 and lever 3 swings -in a `counterclockwise direction about roller bearing 5. At the same time, the levers rotate relative to eachother about the common pivot pin 4, and additionally, a lateral movement exists between the roller 5 carried by lever 3 andthe bearing plate 6 which moves the lever 3 relative to the rail 15. Due to the reaction of roller 5 on the plate 6, the upper lever 1 rotates about the fulcrum 2 and this action raises the common fulcrum` 4 and causes the lower lever 3 and hence braking shoes 14 to move in arcs to lift the brake shoes and close the gap between the two brake shoes, thereby imparting the required braking force to Ya car wheel running along the rail 15. This interrelation of movement between the different fulcrum points causes the braking bars carried by the levers to be moved toward the car wheel and also moved upwardly a considerable distance above their vnormal positions, thereby allowing the brake shoes to engage -the car Wheel at the side surfaces well above the wheel tread. When the levers 1 and 3 have been moved apart by admitting pressure to the motor 7 in the manner just described, and the cylinder 7a is subsequently disconnected from the source of pressure and is vented to atmosphere, the free ends of the levers 1 and 3 will move toward eachother under the influence of gravity in vthe manner previously described. During this movement the operation is merely the reverse of fthe braking process and lateral movement of the roller bearing 5 is in a direction away from rail 15. Y Y

As is readily apparent, our novel fulcrum lever arrangement accomplishes the braking bar raising effect and the wide spacing of the braking bars in their nonbraking position with a relatively short stroke piston motor. Further, it will be readily understood that the amount of braking bar raising and -the relative spacing between the braking bars is determined by thefulcrum point placement and the length of the levers, so that any desirable amount of raising and spacing of the braking bars may be acquired by merely shifting the fulcrum points or changing the vdimensions of the levers.

While our invention has been described with reference to a particular embodiment thereof, it will be understood that various modifications may be made by those skilled in the art without departing from the invention. The appended claims are therefore intended to cover all such modifications within the trueY spirit and scope of the invention.

Having thus described our invention, what we claim is:

I 1. Railway braking apparatus comprising two levers pivoted about a first fulcrum located beneath a track rail, a second tixed fulcrum securely fastened relative to and on one side of said rail for pivotally supporting one of said levers, a third fulcrum located on the other side of said rail for pivotally supporting the other of said levers, a braking bar located on each side of said rail and supported by said levers, and a motor connected to and supported by said levers for forcing each braking bar upwardly and toward said rail.

2. Railway braking apparatus comprising two braking bars disposed on opposite sides of a track rail, two levers one for supporting each of said braking bars, said levers being pivoted about a iirst common fulcrum disposed beneathsaid rail, one of said levers being additionally pivoted and lixedly supported with respect to said rail about a second fulcrum located at one end of said one lever, the other of said levers being additionally pivoted and supported about a third fulcrum located intermediate the ends of said other lever, and motor means supported by said levers for moving said braking bars upwardly and toward said rail into an effective braking position.

3. Railway braking apparatus comprising two braking bars extending parallel to a track rail on opposite sides of the rail, said braking bars comprising a plurality of brake beams aligned in end to end relation and brake shoes attached to said brake beams, a plurality of operating units disposed at intervals along said rail for supporting said braking bars, each operating unit comprising two levers pivoted about a first fulcrum positioned below the rail, a second fixed ulcrum positioned on one side of said rail for pivotally supporting one of said levers, a third fulcrum positioned on the other side of said rail for pivotally supporting the other of said levers, a duid motor attached to and carried by said levers for raising and laterally moving said braking bars toward the rail into a braking condition, and the parts being so proportioned that gravity biases the levers for lowering and laterally moving said braking bars away from the rail into a nonbraking condition.

4. Railway braking apparatus comprising two braking bars extending parallel to a track rail on opposite sides of the rail, said braking bars comprising a plurality of aligned brake beams and brake shoes attached to said brake beams, a plurality of iluid pressure operating units spaced at predetermined intervals along the rail for supporting said braking bars, each iluid pressure operating unit comprising two levers pivoted about a tirst common fulcrum positioned below the rail, one of said levers being additionally pivoted and xedly supported with respect to said rail about a second fulcrum located at one end of said one lever, the other of said levers being additionally pivoted and supported about a third fulcrum located intermediate the ends of said other lever, and a fluid motor attached to and carried by said levers for raising and laterally moving said braking bars toward the rail wherein said brake shoes engage the sides of a car wheel traversing the rail.

5. Railway braking apparatus comprising a pair of braking bars located on opposite sides of a track rail, a pair of levers one for supporting each of said braking bars, a pivot pin disposed beneath the rail for interconnecting said levers for relative rotational movement thereabout, a journal assembly xedly secured on one side of the rail for supporting one of said levers, a roller bearing fastened to said other lever and cooperating with a bearing plate xedly secured on the other side of the rail for supporting said other lever, and a fluid motor connected to and supported by said levers for moving each braking bar upwardly and toward the rail.

6. Railway braking apparatus comprising two braking bars extending parallel to a track rail and movable upwardly toward and downwardly away from the rail into braking and nonbraking positions, two levers one for supporting each of said braking bars, said levers being pivoted about a pivot pin disposed beneath the rail, one

6, of said levers being additionally pivoted and supported about a journal assembly means disposed on one side of the rail, the other of said levers being additionally pivoted and supported about a -roller bearing means disposed on the other side of the rail, the parts being so proportioned that the braking bars are normally gravity biased downwardly away from the rail into the nonbraking position, and a uid pressure means connected to said levers for moving the braking bars upwardly toward the rail into the braking position.

7. Railway braking apparatus comprising two braking bars disposed beside a track rail and adapted to be moved upwardly toward and downwardly away from the rail into braking and nonbraking conditions, a rst and a second lever for supporting said braking bars, said levers being pivoted about a pivot point located intermediate their ends, said rst lever being additionally pivoted at one end about a irst pivotal support disposed on one side of the rail, said second lever being additionally pivoted intermediate its end about a second pivotal support disposed on the other side of said rail, a uid pressure motor attached to the other end of said rst lever and said one end of said second lever for actuating said braking bars upwardly and toward the rail into engagement with the sides of a car wheel traversing the rail during the braking condition, and the parts being so proportioned that the braking bars are moved downwardly and away from the rail into the nonbraking condition upon deactuation of said uid pressure motor.

8. Railway braking apparatus Comprising two braking bars extending parallel to a track rail on opposite sides of the rail, said braking bars comprising a plurality of brake beams aligned in end to end relation and brake shoes attached to said brake beams, a plurality of operating units disposed at intervals along said rail for supporting -said braking bars, each operating unit comprising a rst and a second lever pivoted intermediate their ends about a pivot pin positioned below the rail, a journal assembly positioned on one side of said rail for pivotally supporting one end of said first lever, a roller bearing arrangement positioned on the other side of said rail for pivotally supporting said second lever intermediate said pivot pin and one of its ends, a fluid motor attached to and carried by the other end of said lirst lever and the one end of said second lever for raising and laterally moving said braking bars toward the rail and into engagement with the sides of a car Wheel traversing the rail, and biasing means for lowering and laterally moving said braking bar-s away from the rail after passage of said car wheel.

9. Railway braking apparatus comprising two braking bars extending parallel to a track rail on opposite sides of the rail, said braking bars comprising a plurality of aligned brake beams and brake shoes attached to said brake beams, a plurality of iluid pressure operating units spaced at predetermined intervals along the rail for supporting said braking bars, each fluid pressure operating unit comprising a first and a second lever pivoted about a pivot pin disposed beneath the rail, said-rst lever being additionally pivoted and supported about a journal assembly means located at one end of said rst lever, said second lever being additionally pivoted and supported about a roller bearing means located intermediate the ends of said other lever, and a iluid motor attached to and carried by said levers for raising and laterally moving said braking bars toward the rail wherein said brake shoes engage the sides of a car wheel traversing the rail, and the parts being so proportioned that said levers are baised by gravity for lowering and laterally moving said braking bars away from the rail after passage of the car wheel.

10. Railway braking apparatus comprising two braking bars extending parallel to a track rail and movable upwardly toward and downwardly away from the rail into braking and nonbraking positions, a plurality of luid pressure operating units disposed at intervals along the rail, each said fluid operating unit comprising a rst and a second lever one for supporting each of said braking bars, said levers being pivotal-1y mounted for rotation intermediate their ends about a pivot pin disposed beneath the rail, said rst lever being additionally pivotally mounted for rotation at one of its ends about a journal assembly means securely fastened 011 one side of the rail, said second lever being additionally pivotally mounted for rotation and `lateral movement intermediate its one end and said pivot pin on a roller bearing means disposed on the other side of the rail, said operating units being so proportioned that the braking bars are normally gravity biased downwardly away from the rail into the :nonbraking position and a uid pressure motor 8. means connected to the other endof said rst :lever andsaid one end of said second lever for moving the braking bars upwardly toward the rail into the braking position.

References Cited by the Examiner UNITED STATES PATENTS 2,345,488 3/44 Logan' 18a-s2 L2,55992 7/51 Bone 18s-62 FOREIGN PATENTS 694,212 7/53 Great Britain.

ARTHUR L. LA POINT, Primary Examiner.

DUANE A. REGER, Examiner.

Claims

1. RAILWAY BRAKING APPARATUS COMPRISING TWO LEVERS PIVOTED ABOUT A FIRST FULCRUM LOCATED BENEATH A TRACK RAIL, A SECOND FIXED FULCRUM SECURELY FASTENED RELATIVE TO AND ON ONE SIDE OF SAID RAIL FOR PIVOTALLY SUPPORTING ONE OF SAID LEVERS, A THIRD FULCRUM LOCATED ON THE OTHER SIDE OF SAID RAIL FOR PIVOTALLY SUPPORTING THE OTHER OF SAID LEVERS, A BRAKING BAR LOCATED ON EACH SIDE OF SAID RAIL AND SUPPORTED BY SAID LEVERS, AND A MOTOR CONNECTED TO AND SUPPORTED BY SAID LEVERS FOR FORCING EACH BRAKING BAR UPWARDLY AND TOWARD SAID RAIL.