US3819017A

US3819017A - Controllable skate car retarder

Info

Publication number: US3819017A
Application number: US00320323A
Authority: US
Inventors: P Noble
Original assignee: Westinghouse Air Brake Co
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1973-01-02
Filing date: 1973-01-02
Publication date: 1974-06-25
Anticipated expiration: 1991-06-25

Abstract

This invention relates to a controllable railway skate car retarder including a plurality of levers pivotally supported on the cross ties and disposed on the respective sides of a track rail. The pivotal levers support elongated braking elements which are disposed parallel to the track rails. Each of the outer levers of the car retarder is operated by a power actuator. Each power actuator includes a fluid operated piston and cylinder as well as a mechanical toggle linkage to raise and lower the levers to cause the braking elements to assume a braking or nonbraking position.

Description

United States Patent [191 Noble June 25, 1974 CONTROLLABLE SKATE CAR RETARDER [75] Inventor: Peter M. Noble, Valencia, Pa.

[73] Assignee: Westinghouse Air Brake Company,

Swissvale, Pa.

[22] Filed: Jan. 2, 1973 [21] Appl. No.: 320,323

[52] US. Cl. 188/62 [51] Int. Cl B6lk 7/08 [58] Field of Search 188/32, 62

[56] References Cited UNITED STATES PATENTS 2,285,327 6/1942 Brown 188/62 3,403,752 10/1968 Garrett et al. 188/62 Primary ExaminerDuane A. Reger Attorney, Agent, or Firm-H. A. Williamson; .1. B.

Sotak [5 7] ABSTRACT This invention relates to a controllable railway skate car retarder including a plurality of levers pivotally supported on the cross ties and disposed on the respective sides of a track rail. The pivotal levers support elongated braking elements which are disposed parallel to the track rails. Each of the outer levers of the car retarder is operated by a power actuator. Each power actuator includes a fluid operated piston and cylinder as well as a mechanical toggle linkage to raise and lower the levers to cause the braking elements to assume a braking or nonbraking position.

10 Claims, 3 Drawing Figures PAIENTEDJUNZEIHH 3.819.017

SHEEI 1 0F 2 Gender Fau'd 1 CONTROLLABLE SKATE CAR RETARDER This invention relates to a weight proportional skate car retarder which is operably actuated to assume either a braking or a nonbraking position. More particularly, this invention involves an actuating mechanism for controlling the condition of a car Wheel frictional engaging type of railroad braking apparatus.

It is conventional practice to employ skates or chocks at the exiting ends of the railway class tracks in classification yards and also at the certain points in industrial and commercial sidings or spur tracks to brake and stop oncoming railway vehicles and subsequently to hold them in place. The skate or chock is generally manually placed on one or both of the rails of the trackway so that the treadle or circumferential surface of the wheel or wheels will cause frictional retardation and will result in the halting of the railway vehicle. In order to alleviate the shortcomings, such as, the manual placement and removal of the skates or chocks by a brakeman or other personnel, it is preferable to employ vehicle stopping apparatus which require little, if any, handling by attending workmen. It is now becoming common railroad practice to utilize a weight proportional or inert car retarder in place of the previously used skates or chocks. However, the railroad industry is now faced with the problem of noise pollution, such as, the wheel screeching sounds that are generated when the railway vehicles are pulled from the bowl class tracks through the skate retarder by a departure yard locomotive or engine. In view of the recently enacted noise abatement ordinances by many of the cities, towns, and other municipal governments, it is mandatory to suppress or at least decrease the level of the squealing sounds that are produced by frictional wheel engaging car retarders. In addition, the passage of the Occupational Safety and Health Act requires the employer assure as far as possible every working man and woman in the nation safe and healthful working conditions and to preserve our human resources. The scope of the Act encompasses noise pollution, and thus the wheel squealing noise produced in a frictional type of skate carretarder must be dramatically reduced and preferably eliminated, particularly, during withdrawal or pullout periods. The wheel squealing noise is produced by the brake shoes, frictionally rubbing the sides of the moving car wheels which results in severe vibrational agitation that results in extremely loud and intense sounds to be created during a pullout operation. Thus, it is necessary to maintain the retaining or braking function of the skate retarder during classification operation, but it is essential to avoid generating wheel squealing or screeching during pullout operation. As mentioned above, the noise problem is caused by the rubbing action that takes place between the wheels and brake shoes. Hence, the wheel squealing sounds may be completely eliminated by precluding any braking effort to occur when railway vehicles are pulled through the weight proportional skate car retarder by a departure engine. In addition, the frictional rubbing action causes excessive mechanical wear on the brake shoes or braking rails which drastically reduces the useful life of the braking elements. It has been found that the abrasive action ordinarily occurring during pullout dramatically reduces the life of the braking elements which greatly increases the maintenance cost of the retarder. In addition, the accelerated abrasion also demands frequent adjustments of the braking elements for maintaining effective and efficient retarder operation. Hence, it is desirable to normally maintain the skate car retarder in its braking position during classification of the railway vehicles and to periodically move the skate car retarder to its nonbraking position during withdrawal of the railway vehicles. Further, the required demand or load on the departure yard engine is drastically reduced by the elimination of frictional drag on the car wheels.

Accordingly, it is an object of this invention to provide a weight proportional car'retarder for effectively braking the wheels and stopping free rolling railway cars and for holding the wheels and for selectively allowing-the free passage of the wheels of the moving railway cars.

A further object of this invention is to provide a controllable skate car retarder which is movable between a braking and a nonbraking position.

Another object of this invention is to provide an actuating mechanism for a weight proportional skate car retarder which brakes the wheels of railway vehicles during classification operation and which allows the free passage of the wheels of the railway vehicles during pullout operation.

Still another object of this invention is to provide a plurality of actuating assemblies for opening a skate type of car retarder so that little, if any, wheel squeal will be produced when railway cars'are withdrawn by an engine.

Still a further object of this invention is to provide a railway weight proportional car retarder which normally frictionally engages the wheels for stopping railway cars and which is operated to disengage the wheels so that screeching sounds will not be generated when the railway cars are pulled out of the retarder.

Yet another object of this invention is to provide an operable weight proportional skate car retarder having a plurality of operating units which are moved to a braking position for stopping oncoming railway cars and which are moved to a nonbraking position for allowing free withdrawal of the railway cars so that noise pollution is. avoided and frictional wear is reduced.

Yet a further object of this invention is to provide a unique releasable skate type of railway car retarder which is economical in cost, simple in construction, easy to install, reliable in operation, durable in use, and efficient in service.

Briefly, the objects of this invention are achieved by providing actuating mechanisms for a skate type of weight proportional car retarder having a plurality of operating units including a pair of levers and frictional braking elements mounted on opposite sides of the track rail. Each of the actuating mechanisms includes a fluid power operator and a mechanical toggle linkage. The fluid power operator includes an external cylinder and an internal piston for moving an extendable rod member. One end of the cylinder is pivotally connected to a clevis block carried by a flat steel support or base plate which is mounted and securely fastened to the top of the cross tie. The other end of the cylinder accommodates the extendable piston rod which is selectively moved between a retracted and an extended position. The mechanical toggle linkage includes an upper link or arm and a lower link or arm. The lower end of the lower arm is pivotally connected to a metallic pin or shaft which is carried by the steel base plate. The upper end of the upper arm is pivotally connected to a journal pin which is securely fastened to the lower outer extremity of one of the pair of pivotal levers. An upstanding stop member is also mounted on the upper surface of the tie-carried base plate to limit the motion of the toggle linkage and to ensure that the operable lever assumes its appropriate upward braking position. That is, the extension of the piston and rod member causes the upper and lower links of the toggle linkage to become substantially aligned so that the operable lever is raised causing the braking elements to close and assume a braking position. Conversely, the retraction of the piston causes the toggle linkage to collapse so that the retarder will assume its nonbraking position.

The above objects and other attendant features and advantages of this invention will become more fully evident from the following detailed description when considered in connection with the accompanying drawings, wherein: with FIG. 1 is a top plan view of a skate type of weight proportional car retarderof the present invention showing the two end operating units and two intermediate operating units the other intermediate operating units being broken away for the purpose of convenience.

FIG. 2 is an enlarged fragmentary side elevational view of the car retarder embodying the present inventlon.

FIG. 3 is a partial vertical sectional view taken along the lines lIIlII of FIG. 2 of one of the operating units of the skate type of weight proportional car retarder constructed in accordance with the present invention.

Similar reference characters will refer to analogous parts throughout the several views of the drawings.

Referring now to the drawings, and in particular to FIG. 1, the reference characters R1 and R2 designate the rails of a stretch of railway track over which the wheels of railway cars traverse and enter the braking apparatus embodying the invention. It will be understood that the rails R1 and R2 are suitably connected to the respective ends of the class or stock rails S1 and S2 in the usual manner by means of rail joints. It will be appreciated that the fasteners or spikes for securing the stock rails allow sufficient vertical lift of the rails for a suitable distance outside the ends of the retarder to permit the running rail in the retarder to lift a given amount. In practice, a conventional 33 ft. retarder will have a vertical movement of approximately V2 of an inch at 6 ft. outside the end of the retarder. It will be understood that the fastening of the rails R1 and R2 to the stock rails at the other end is effected in a corresponding manner. As shown, the stock rails S1 and S2, as well as the rails R1 and R2, rest upon the wooden cross ties CT which are suitably anchored in a conventional manner, such as, being set in ballast in the ground.

As shown, the rail R1 of the braking apparatus or weight proportional car retarder is preferably supported and carried by a plurality of suitably spaced operating units OU, each of which consists of a pair of substantially identical

pivotal levers

2A and 2B, of the general known type, disposed laterally on opposite sides of the rail R1. In viewing FIG. 3, it will be noted that the

pivotal levers

2A and 2B are weldments, each being an assembly of pieces that are welded together. As shown, the two

levers

2A and 2B have their inside bottom portions securely held in suitable relationship by means of a through tie bolt 3. As shown in the drawings, the upper surface of the inside bottom portions of each of the

levers

2A and 2B carry the flange or base portion of the rail R1. The lower surfaces of the inside bottom portions of each of the

levers

2A and 2B include a contact rod or bar 4a and 4b, respectively. The contact rods 4a and 4b normally rest upon the upper surface of the horizontal bearing plate 5a of a suitable cradle 6. The cradle 6 includes vertical supporting plates 5b and 50 which are secured, such as, being welded to the upper surface of a support plate 7. The plate 7 rests on the top and is suitably secured, such as being bolted, to the wooden cross tie CT. In order to provide a more stable supporting arrangement the bearing plate 7 is welded to a pair of oppositely disposed angle irons 8a and 8b which are tied to the cross tie CT by through bolts 9. As shown, the upper inner end of each of the

levers

2A and 2B of the operating units supports the braking elements which may consist of conventional braking rails, or, as shown,

brake beams

10A and 10B and

removable brake shoes

11A and 11B. In viewing FIG. 3,.it will be noted that the

brake shoes

11A and 11B are adapted to frictionally engage the opposite sides of a car wheel 13 when the weight proportional'car retarder is in its braking positron.

For the sake of convenience, let us assume that the presently described weight proportional car retarder is located at the exit end of a class track in a multi-track railroad classification yard. In such an environment the car retarder is normally set in its closed position, in order to brake and stop the oncoming cars by frictionally engaging the opposite sides of wheels of the cars, as shown in FIGS. 2 and 3. Normally, the first railway car or vehicle of a string of cars is stopped by the car retarder to prevent the remaining oncoming vehicles from exiting the class track until such time as it is desirable to withdraw or pull out the string of cars for makeup in the departure yard. When the cars in the class track are ready for makeup, a departure yard locomotive or engine enters the class track and couples to the first car and pulls the string of cars from the class track. It has been found that the pulling of the cars through a closed skate type of weight proportional car retarder results in severe wheel squeal due to the frictional rubbing action occurring between the

brake shoes

11A and 11B and the sides of the wheel 13. The noise emanating from the retarder not only is annoying but also is harmful to attending personnel since car retarder noise levels have been measured well in excess of db (decibels) which is well in excess of the threshold of pain level. In addition, in some yard installations the wheel squealing sounds are in violation of the noise abatement ordinances of the community. Thus, in order to comply with local, state, and federal law, it is necessary to reduce and preferably to eliminate the wheel squeal caused during pullout or withdrawal operations.

Thus, in order to eliminate the noise problem as well as to reduce the mechanical wear on the

brake shoes

11A and 11B, and to lessen the pullout load on the departure yard locomotive, it is advantageous to move the retarder to an open or nonbraking position during pullout. As shown in FIG. 1, the outside end of the inner lever 2B is pivotally mounted on a suitable supporting stand or member 9. The stand 9 positions the lever 2B to be at approximately the same height of the outer le vers 2A when they are in their braking position. The

predetermined fixed heights are determined by the average width of the transversing car wheels to ensure that maximum braking efforts are exerted on the wheels as they enter the weight proportional car retarder. As shown in FIG. 1, each of the operating units OU includes a selectively operated actuating mecha nism AM. It will be appreciated that each of the actuating mechanisms AM is'similar and substantially identical in construction and, therefore, the details of only one of the mechanisms AM need be described to fully understand the structural features and the functional operation thereof. Each of the actuating mechanisms AM includes a fluid power operator PO and a mechanical toggle linkage TL.

The fluid power operator includes a dual inlet cylindrical member and an internal piston (not depicted) which is attached to a piston rod 21. The piston and piston rod 21 are movable between an extended and contracted position by a suitable supply of pneumatic or hydraulic pressure, such as, a wayside fluid source PS. The fluid source FS generally includes a reservoir, a motor driven pump or compressor and an electrofluidic control valve which may be remotely operated from a control center, such as the tower of the yardmaster, or via a local control switch. The fluid source FS is located alongside of the retarder and is coupled to the respective inlets of the cylinder 20 by means of conduit lines L1 and L2 and

flexible hoses

22 and 23, respectively. The closed or back end of the piston rod 21 is provided with a clevis member 25 which is pivotally connected to a pin or rod 26. The pivot pin 26 is carried by a support block 27 that is fixedly secured, such as by welding, to the upper surface of the flat horizontal base of plate 28. The base plate 28 is securely fastened to the top of a cross tie CT by means of lag bolts 29, or the like. The flat base plate 28 provides an appropriate support for the remaining parts or elements of the actuating mechanism AM which may be put together at a subassembly location. It will be appreciated that the base plate 28 facilitates the positioning and assembling of the various parts of elements of the actuating mechanism AM. As shown, the open or rod end of the cylinder 20 is fitted with a bearing and seal for the piston rod 21. The remote or free end of the piston rod 21 is coupled to the intermediate pivotal connection of the mechanical toggle linkage TL. The intermediate pivotal connection of the toggle linkage TL includes a pivot or pin 30 having an enlarged central spacer portion 31. The lower link or support arm includes a pair of elongated inside plates 32. The upper ends of each of the plates 32 are journaled about the respective reduced ends of the pivot pin 30. As shown, the lower end of each of the elongated link plates 32 is journaled about a lower pivot pin or rod 33. The pivot pin 33 is fixedly secured, such as by welding, to a toggle support block 34 which is mounted to the top of base plate 28. The upper link or supporting arm also comprises a pair of elongated outside plates 35. As shown, the lower end of each of the plates 35 is journaled to the intermediate pivot pin 30 while the upper end of each of the plate members 35 is journaled to the respective ends of a pivot pin or rod 36. The pin 36 is securely attached, such as by being spot welded to the underside of the outer end of the outer lever 2A. The upper and lower linkage plates are retained on the respective pivot pins by means of conventional cotter pins, or the like.

A stop member 37 in the form of a ribbed angle bracket is located adjacent the toggle linkage TL. The base leg of the angle bracket is bolted to the top of the base plate 28. The bolts 38 are received by elongated apertures formed in the base leg of the bracket 37 to allow for adjustment. In viewing FIG. 3, it will be noted that the intermediate pivotal point abuts the surface of the upstanding leg of the stop member 37 when the piston rod 21 of the power operator PO is fully extended. It will be noted that the upper and lower links are slightly offset or oblique relative to each other. That is, the upper and

lower arms

32, 35 are moved past the perpendicular center line so that a slight angle exists at the intermediate pivot point. This ensures that the horizontal vectorial force will constantly urge the toggle linkage against the adjacent face of the stop member 37. Thus, once the lever 2A is placed in its upper braking position, there is no need to supply pressure on the back side of the piston member via line L1 and hose 22. Accordingly, once the lever 2A is raised to its upper braking position, no further energy need be expended in maintaining it in its braking position. Thus, obliquity of the

links

32 and 35 maintains the retarder in its upper braking position until other positive action is taken as will be described presently.

In a classification yard environment, the car retarder is generally held in its braking position until such time as it is desired to withdraw the railway vehicles from a particular class track. If it is desired to pull the string of vehicles from the class track, the retarder is opened or moved to its nonbraking position. in order to move the car retarder to its nonbreaking position, it is simply necessary to apply pressure to the line L1 from the fluid source FS and to have the line L2 vented, for example, to the atmosphere in a pneumatic system or to a reverse or accumulation tank in a hydraulic system. If or when a given retarder or lever unit thereof is unlocked, i.e., no car wheel in proximity, the pressure as above will cause the piston and, in turn, the piston rod 21 to be retracted. The retracting of the piston and rod causes the toggle linkage TL to move to and assume a position as shown in phantom in FIG. 3. Thus, the levers 2A are lowered to a point where the gap between the

brake shoes

11A and 11B become larger than the width of the car wheels 13 so that no rubbing action takes place. Thus, free passage of the vehicles is permitted without generation of wheel squeal and without mechanical frictional wear on the wheel engaging surfaces of the brake shoes. After the last car has been withdrawn, the retarder may be moved to its braking position simply by applying pressure to the line L1 from the fluid source FS and venting the other line L2. Thus, the piston extends the rod 21 which causes the toggle linkage TL to be moved to the position, as shown, by the solid lines in FIG. 3. Thus, the car retarder is returned to its braking position so that the forthcoming vehicle of the next string of cars to be closed is held until pullout time.

In practice, the position of the car retarder is normally controlled by an operator located in the central control tower of the classification yard. As previously mentioned, once the levers are moved to their raised position, the offset links of the toggle linkage TL abut the stop member 37 so that the source of pressure may be immediately removed so that power consumption is minimized. In addition, the over-the-center position of the toggle linkage ensures that no excessive back pressure is exerted on the feed lines of the supply system so that leakage and fluid losses are not a problem.

From the foregoing description it will be noted that the presently described invention utilizes a simple, yet efficient, arrangement for actuating and controlling a weight proportional skate car retarder which provides sufficient braking effort to stop oncoming vehicles and for holding the wheels for an indefinite length of time and yet selectively allows the free passage of railway cars through the retarder during withdrawal or pullout operation.

While the presently disclosed skate retarder equipment has been described in relation to classification yards, it is readily understood that the present invention may be employed in other applications, such as, car dumping, industrial sidings, as well as in other environmental surroundings'having need of my invention. But regardless of the manner in which the invention is used, it is understood that various alterations may be made by persons skilled in the art without departing from the spirit and scope of this invention. It will also be apparent that any modifications and changes can be made in the presently described invention and, therefore, it isunderstood that all changes, equivalents, and modifications within the spirit and scope of this invention are herein meant to be included in the appended claims.

Having thus described my invention, what I claim is:

1. An arrangement for selectively controlling a railroad car retarder comprising, a plurality of operating units, each of said operating units including an inner and an outer lever disposed normally to the length of the railroad track, a brake beam disposed on opposite sides of at least one of the rails of the railroad track and carried by the respective inner and outer levers, at least said outer levers of said plurality of operating units pivotally supported near their outer extremities by an actuating mechanism, said actuating mechanism including a toggle linkage and a power operator, said toggle linkage having a lower pivotal support arm and an upper pivotal support arm, said power operator including a cylinder and a piston, said piston connected to said upper and lower support arms so that the extension of said piston moves said upper and lower support arms to a first position thereby causing the car retarder to assume its braking position and so that the retraction of said piston moves the upper and lower support arms to a second position thereby causing the car retarder to assume its nonbraking position.

2. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein said cylinder of said power operator is pivotally connected to a supporting member and is powered by a source of fluid pressure. a

3. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein a stop member is engaged by the intermediate pivot of said toggle linkage when said upper and lower support arms assume said first position.

4. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein the free end of said lower support arm of said toggle linkage is pivotally mounted to a cross tie supported clevis block.

5. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein the free end of said upper arm of said toggle linkage is coupled by a pivot pin carried by said outer lever.

6. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein said cylinder is pivotally connected to a clevis block which is carried by a base plate mounted on a cross tie.

7. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein said upper and said lower arms of said toggle linkage each include a pair of dual aligned plate members.

8. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein a bearing plate is secured to the top of a cross tie for carrying said actuating mechanism.

9. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein said cylinder is coupled to a source of fluidic pressure which moves said piston between its extended and retracted positions.

10. A controllable skate car retarder comprising, a plurality of pairs of levers pivotally supported on the cross ties and disposed on the respective sides of the track rail, elongated frictional wheel braking members supported by each of said levers and positioned parallel to the track rail, a power operating actuator including a supporting member located on one side of the track rail and securely fastened to the respective cross ties, a pneumatic cylinder and piston, said pneumatic cylinder carried by said supporting member and said piston connected by a toggle linkage assembly to one of said pair of levers for raising and closing the car retarder to cause a braking action on the passing car wheels and for lower and opening the car retarder to allow free passage of the car wheels.

Claims

2. An arrangement for selectively controlling a railroad car retarder as defined in claim 1, wherein said cylinder of said power operator is pivotally connected to a supporting member and is powered by a source of fluid pressure.