US3557910A

US3557910A - Railroad car retarders

Info

Publication number: US3557910A
Application number: US830020A
Authority: US
Inventors: Rosser L Wilson
Original assignee: Abex Corp
Current assignee: ABC Rail Corp; American National Bank and Trust Company of Chicago
Priority date: 1969-06-03
Filing date: 1969-06-03
Publication date: 1971-01-26
Anticipated expiration: 1988-01-26
Also published as: CA925060A

Abstract

A railroad car retarder, adapted for installation in a classification yard or the like, and of the weight-compensating type, is so constructed as to include an artificial wheel load specifically designed to improve operation of the car retarder from the standpoint of lightly loaded vehicles. This artificial preload may be a spring.

Description

United States Patent {72] Inventor RosserL.Wilson Mahwah, NJ. [21 AppL No, 830,020 [22] Filed June 3,1969 [45] Patented Jan. 26, 1971 [73] Assignee Abex Corporation New York, N.Y. a corporation of Delaware [54] RAILROAD CAR RETARDERS 5 Claims, 3 Drawing Figs.

[52] U.S.Cl 188/62 [5 1] Int. Cl B6lk 7/06 [50] Field of Search 188/62 [56] References Cited UNlTEQ STATES PATENTS 1,840,250 l/l932 Prescott 188/62 3,227,246 l/l966 Wilson 188/62 3,332,524 7/1967 Tilden et al l88/62X Primary Examiner-George E A. Halvosa Att0meyl(inzer, Dorn and Zickert ABSTRACT: A railroad car retarder, adapted for installation in a classification yard or the like, and of the weight-compensating type, is so constructed as to include an artificial wheel load specifically designed to improve operation of the car retarder from the standpoint of lightly loaded vehicles. This artificial preload may be a spring.

PATENTED JANZB |97| sum 2 BF 2 Inventor Rosser LJ/Uflson RAILROAD CAR RETARDERS This invention relates to railroad car retarders and in particular to a retarder of the type described and claimed in US. Pat. No. 3,227,246 where the lever arms of the retarder include portions which cradle and support the traffic rail on which the car wheel moves. Thus, the traffic rail in effect floats on the retarder, and the retarder is responsive to the weight of the car, which is to say that the heavier the car the more effective the retarding action. It is generally known, however, that weight-compensating retarders of this kind may not be as effective for an empty car as for a loaded car, inasmuch as the lighter loads do not actuate the retarder as effectively as heavier loads. The primary object of the present invention is to compensate for the partial inefficiency by in effect preloading the retarder by a spring or equivalent resilient member which adds its effect to the effect of the actual load when the retarder is actuated. Specifically it is an object of the present invention to interpose a unique spring arrangement in the retarder system of US. Pat. No. 3,227,246.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principle thereof and what is now considered to be the best mode contemplated for applying this principle. Other embodiments of the invention embodying the same or equivalent principles may be made as desired by those skilled in the art without departing from the present invention.

In the drawings, FIG. 1 is an elevation, partly in section, of a retarder constructed in accordance with the present invention;

FIG. 2 is a detail view of the preload spring and its support; and

FIG. 3 is a detail view of a modification.

The present disclosure assumes the car retarder of US. Pat. No. 3,227,246 herein incorporated by reference. FIG. 1 hereof is identical to FIG. 6 of the patent except for the spring and its support.

Referring now to the drawings, and more particularly to FIG. 1, spaced railway ties as I support spaced running or traffic rails as 11 which serve to support the wheels of a railway car in the conventional manner.

While the retarder 13 is illustrated in FIG. I as being applied to only one traffic rail 11, it is understood that the other traffic rail may be provided with a like retarder identical in construction to the one disclosed.

The retarder 13 functions to brake a railway car moving therethrough. In the present instance, the retarder system 13 can be selectively controlled to position a pair of braking rails or retarder elements 15 adapted to engage opposed sides of a car wheel riding on the top portion 18 of the traffic rail 11, functioning to retard rotation of the car by frictionally engaging the sides of the wheels. The retarder elements 15 are shown in the form of rails and for reasons of economy are often scrap railway rails; but the invention herein is not to be construed as limited thereto.

When in normal or cocked position, the rails 15 are spaced apart a distance less than the width of the car wheel, so that their wheel-engaging surfaces 22 when engaged by the sides of the wheel, are forced outwardly by the car wheel moving between the braking rails 15. Each of the braking rails 15 is a unitary rail, and each is supported at spaced positions by a plurality of levers 25 pivotally mounted on a portion 26 of a rock shaft 27 which spans a pair of adjacent railway ties 10.

Each of the braking rails 15 has a web 30 overlying a horizontal plate 31 on the levers 25. The plate 31 is integrally fixed to the lever 25 and extends horizontally outward along the web 30. Each of the webs 30 is secured to a plurality of plates 31 on the respective levers 25 by bolts 32 inserted through elongated holes or slots (not shown) in the webs 30 and the plates 31.

The braking rails 15 are subjected to large laterally directed forces as the railroad car wheel moves therebetween as shown and described in the aforesaid patent. The lateral forces or thrusts are transmitted by wedges 35 to the levers 25. The wedges 35 are positioned between an end flange 36 of the braking rail 15 and a curved seat 37 on the lever 25. The wedges 35 serve as a solid interconnection between the rails 15 and levers 25 and afford a means of adjustment for wear compensation whereby the rails 15 can be moved laterally towards the railway wheel as described in said patent.

The levers 25 that support the abrasion rails 15 are identically constructed in principle, there being slight differences allowing for different geometry in the right and left sides of the car wheel. The levers 25 provide a monolithic structural member which not only supports the abrasion rails 15, but which also affords cradle portion 45 for supporting the traffic rail 11. In this sense, during retardation of a car, the traffic rail is lifted with the car and in effect floats on the cradle 45, so that the weight of a car tends to exert a downward force to depress the traffic rail.

Additionally, the levers 25 serve as the means whereby a retarding force may be exerted on the car wheel in proportion to the weight of the car being supported by the car wheels. More specifically, the movement of a car wheel through the retarding system 13 establishes lateral thrust, causing the lever arms 25 to pivot about the eccentric portions 26 of the rock shaft 27 to lift the traffic rail 11. The heavier the weight of the car, the greater will be the force resisting the lifting of the traffic rail 11 and the car wheel, and hence the greater the force acting to bring the abrasion rails 15 into tighter and greater frictional engagement with the sides of the car wheel. Thus, for heavy cars, the amount of frictional force retarding the car will be greater, since the downward force on the traffic rail 11 will be greater than that for a lighter railway car, holding the braking rails 15 in tighter engagement with the sides of the car wheel.

The cradle portion 45 of each lever 25 has a central hump or rounded projection presenting a surface 46 in engagement with the under surface of the flange 48 of the rail 11. In addition to the supporting surface 46, the cradle 45 for the rail 11 includes an overhanging lip or flange 49 at the inner end of each lever 25 loosely embracing the traffic rail and forming a pocket 50 with surface 46. Positioned in the pocket 50 is that portion of the flange 48 remote from the abrasion rail 15 carried by the lever 25. Since the opposed levers 25 both have these overhanging flanges 49 on opposite sides of the traffic rail 11, the pockets 50 serve in the aggregate to hold the traffic rail 11 against both lateral movements and rotational movements on the rounded surfaces 46 of their respective cradles 45. The flanges 49 also are important from the standpoint that when the retarder system 13 is actuated to an ineffective position, the flanges 49 assure that the railway rail 11 is held on the surface of the railway ties 10 when the car wheels pass thereover.

When the rock shafts 27 are rotated, the eccentrics 26 turn and rotate levers 25 from the cocked, or actuated wheel-engaging position shown in FIG. 1 to the released" position wherein the braking rails 15 are spaced apart a distance greater than the width of the railway wheel thereby rendering the retarder system 13 inoperative.

For the purpose of so turning the eccentrics 26, a hydraulic cylinder 60 is slung beneath the levers 25. One end of the cylinder 60 is provided with a bifurcated portion 61 fastened by a pin 62 to a crank arm 63 on one of the rock shafts 27. The piston rod 65 of the cylinder is connected by a pin 67 to a bifurcated link 66 on a crank arm 68 rigidly secured to the other rock shaft 27. Upon being moved by expansion or contraction of the hydraulic cylinder 60, arms 63 and 68 cause the rock shafts 27 to rotate on the angles as 70 capping and protecting the edges of a pair of adjacent ties 10.

It should be noted that each of the levers 25 is independent of the other except that opposed levers 25 are joined in a sense by a common hydraulic cylinder 60, which may be a double piston cylinder if desired rather than the one shown.

When the retarder system 13 is in an operative position for slowing down or stopping a car, the hydraulic cylinder 60 will have been actuated to its expanded position shown in FIG. 1. The hooked ends of the levers 25 clasping the base of the traf fic rail prevent any outward shifting ofthe rock shafts 27 along the ties under the lateral forces being exerted thereon as the car wheel passes through the abrasion rails 15.

As described hereinbefore, rotation of the crank arms 63 and 68 in response to actuating the hydraulic cylinder 60 to its expanded position, FIG. 1, causes the eccentrics 26 to turn and rotate the levers 25 to move the opposed braking rails 15 toward one another. The amount of the rotation of the levers 25 and thereby the movement of the braking rails 15 toward or away from each other is limited to a predetermined amount of movement by individual stop elements 75 on each of the eccentrics 26 rotating into engagement with an aligned stop element 76 on an associated lever arm 25.

When a brake rail 15 is moved to its maximum retarding position, its associated cylinder rod 65 is completely extended and the rock shaft 27 is rotated to move its stop into engagement with the stop on associated lever 25. Conversely when the retarder is opened fully to its released position, opposed stop surfaces on the rock shafts 27 are in engagement with aligned stop surfaces of the levers 25. Therefore, it will be seen that the

stop elements

75 and 76 limit the amount of rotation of the rock shafts 27 and lever arms 25 and thereby limit the retarder rails 15 to predetennine amounts of opening and closing movements.

Limiting the amount of the rotation of the levers 25 is advantageous in that if one of the levers 25 is reluctant to rotate, all of the force being generated by the hydraulic cylinder 60 is directed to rotating the unwilling lever 25, since the other lever is prevented from further rotation by engagement of the

stops

75 and 76. Thus, rather than having one braking rail 15 move too far in one direction, with little or no movement of the other braking rail 15, the one rail is limited in its movement and all of the hydraulic force is concentrated to move the other rail to its proper position. Additionally, since the

stop elements

75 and 76 limit the amount of the rotation of levers 25, this serves to stabilize and lock in position the traffic rail 11 disposed on the supporting surfaces 46 of the levers 25.

It will be seen from the foregoing that while the levers 25 are pivotally supported for movement laterally of the traffic rail, which axes are represented by the shafts 27, they are at the same time constrained against lateral shifting movement in that the hooked ends of the levers 25 serve to constrain the shafts 27 from any substantial or significant lateral movement. In other words, the retarder system 13 will function independently of the cylinder 60 which is a convenient mode of both opening or spreading the retarder rails 15 laterally and securing the supports for the levers 25 against lateral displacement. Hence, the essential lateral restraint of the pivotal axes for the lever supports may be achieved in other fashions.

The retarder as thus described is most effective on a heavy car. As the car enters the retarder the retarder elements 15 are spread apart tending to raise the traffic rail 11 against the weight of the car imposed thereon. The counter force, in other words, is the weight of the car tending to depress the rail, or hold the rail down, so that the heavier the car the more effective is the clamping force applied to the sides of the car wheel by the retarder elements 15. This is as it should be, since more braking force is required to slow the heavier car to a predetermined low speed, compared to a lighter car.

However, it is generally known that in weight-compensating retarders of this general class, in terms of a straight line relationship, the lighter car is not as effective in actuating the retarder. For example, there is a great deal of friction and inertia in the system, quickly overcome by a heavy car but not so quickly overcome by a lighter car. Under and in accordance with the present invention the retarder is preloaded by a few thousand pounds or so responsible for an improvement in the degree of retardation for empty cars where the need is great and to a lesser degree with heavier cars where the preload is not so important, or needed less. Specifically, the retarder is so loaded by a spring means as to resist, to a degree, elevation of the traffic rail 11 when the retarder is actuated, thereby adding a spring load to the actual wheel load present on the traffic rail. A coil spring is used for this purpose, but another form of resilient preload could be used and could of course be located elsewhere compared to the preferred embodiment shown herein.

Referring to FIG. 1. a large coil spring 80. presenting a 4,000 pound spring load for example, is located on the near side of the tie 10. The upper end ofthe spring 80, FIG. 2, bears on the underside of the horizontal flange 81 of a large angle plate 82 having its vertical leg 83 fastened to the vertical face of the tie 10. A generally U-shaped bracket 85 serves in part to house the spring 80, and the lower end of the spring rests on the upper face of the horizontal leg 87, FIG. 1, of the bracket 85.

The bracket has outwardly bent ears 88 at the upper end thereof, joined to the opposed ears 89 of respective rail hangers 90 by bolts 91. The hangers 90 have claws 92 engaging the upper side of the flange of the traffic rail 11, and consequently the hangers become part of a spring housing 85-92 as a whole. The spring may be placed under compression when installed by tightening, but not necessarily so. i

It will thus be seen that the housing bracket 85-92 will partake of any vertical movement of the rail 11. Thus, if the rail is raised, so is the spring housing. Hence, when a car enters the retarder with the wheel on the traffic rail 11 spreading the retarding elements 15, raising the traffic rail, this is resisted not only by the weight of the car but also by the load presented by the spring 80. It has been determined by field testingthat the spring preload does indeed'enhance the efficiency of the retarder in terms of decelerating low weight or empty cars.

It will be appreciated, as noted above, that the preload need not be in the precise form shown, although the form of the invention here disclosed has been subjected to field testing and found to perform satisfactorily. Nonetheless, the preload could take other forms, such as that shown in FIG. 3.

FIG. 3 shows in dotted line a car wheel C W between the retarder elements 15, tending to spread the levers 25 FIG. 1, andraising the traffic rail 11 as shown by dotted line in FIG. 3. This action would be resisted by a coil spring 80' of less capacity than the spring 80 shown in FIG. 1, but in this modification of the invention the coil spring may be assisted by a fluid cylinder having a piston 101 engaged with the upper end of the spring 80.

When the cylinder 100 is rendered active then it may be remotely controlled to add its effect to that of the spring 80 at the time of retarder actuation, in which event fluid under pressure is admitted to the cylinder 100 through a conduit 105 tending to drive the piston downwardly to add its downward force to that of the spring 80', thereby establishing an even greater equivalent wheel load tending to resist the raising of the traffic rail 11 and thereby increasing the effectiveness of the retarder. The piston may be restored to its idle or inactive state by fluid admitted to the cylinder 100 in an opposing or piston-retracting direction through conduit 106.

The modification of a spring alone, FIG. 1, may be viewed as a fixed or invariable form of artificial wheel load, whereas the artificial wheel load generated by the structure in FIG. 3 may be varied through cylinder 100. In FIG. 3, the wheel load itself is shown by vector WL, and the brake or retarding force by vector BF. The spring 80' may be assumed capable of exerting an artificial or equivalent wheel load (AWL) of 3,000 pounds.

The combined brake force of each side of the wheel, for the lever system shown, is presented by the equation:

from which it will be seen that for an empty car presenting a wheel load of 6,000 pounds, the artificial load is 50 percent of the actual wheel load (3,000:6,000); whereas for a loaded car presenting a wheel load of say 20,000 pounds, the artificial load is only percent of that value (100020900).

lt will thus be seen that under the present invention, the retarder system is one which includes a pair of pivotal levers presenting retarder elements on opposite sides of the traffic rail, nonnally spaced by a distance less than the width of the car wheel. The levers pivot on fixed axes, and also include por tions supporting the underside of the rail. A spring or equivalent resilient means is so interposed in the retarder system as to exert a downward force on the traffic rail; specifically, the upper end of the spring bears against a fixed member, and the lower end bears against a plate anchored to the traffic rail.

When -the levers are spread by the car 'wheel entering between the retarder elements (parts 15) the levers 25 pivot outwardly and tend to raise the traffic rail on which the wheel is supported, but this tendency to raise is resisted by the weight exerted through the car wheel as well as the opposing action of the spring. For a light car, the effect of the spring is large, for a heavy car the effect of the spring is less; and the effect of the spring may be boosted by a cylinder.

lclaim:

1. In a railroad car retarder of the weight-compensating type actuated by and adapted to apply retarding forces to a car wheel riding on a floating traffic rail: a pair of levers presenting opposed retarding elements engageable with opposite sides of the wheel and adapted to be disposed on opposite sides of the traffic rail with the retarder elements normally spaced apart a distance less than the width of the car wheel; said levers having portions supporting the traffic rail; means pivotally supporting said levers for movement toward and away from the car wheel; means constraining the supports for the levers against lateral shifting movement whereby a car wheel on the traffic rail between the retarder elements tends to spread the levers and lift the traffic rail; and a resilient preload means exerting a load on the retarder mechanism in addition to the actual wheel load on the traffic rail, said resilient preload means including a .coil spring disposed immediately beneath the traffic rail, and means for so transmitting the force of the spring as to exert a downward force on the traffic rail when the retarder is actuated.

2. A retarder according to claim l'wherein the resilient preload means exerts a direct downward force on the traffic rail when the retarder is actuated.

3. A retarder according to claim 1 wherein the means which pivotally support the levers include rock shafts to extend parallel to the traffic rail, said shafts having eccentric portions thereon which pivot the levers when the shafts are rocked, and means to rock said shafts having eccentric portions thereon which pivot the levers when the shafts are rocked, and means to rock said shafts including cylinder means operable by fluid under pressure.

4. A retarder according to claim 3 wherein the preload means is a coil spring having its lower end supported by a housing connected to the traffic rail for movement therewith and wherein the upper end of the spring is fixed against movement.

5. A retarder according to claim 1 having a cylinder operable by fluid under pressure interposed between the traffic rail and the top of the spring, said cylinder being operable to apply a thrust to the spring, and means for transmitting the force of the spring as a downward force on the traffic rail.

Claims

1. In a railroad car retarder of the weight-compensating type actuated by and adapted to apply retarding forces to a car wheel riding on a floating traffic rail: a pair of levers presenting opposed retarding elements engageable with opposite sides of the wheel and adapted to be disposed on opposite sides of the traffic rail with the retarder elements normally spaced apart a distance less than the width of the car wheel; said levers having portions supporting the traffic rail; means pivotally supporting said levers for movement toward and away from the car wheel; means constraining the supports for the levers against lateral shifting movement whereby a car wheel on the traffic rail between the retarder elements tends to spread the levers and lift the traffic rail; and a resilient preload means exerting a load on the retarder mechanism in addition to the actual wheel load on the traffic rail, said resilient preload means including a coil spring disposed immediately beneath the traffic rail, and means for so transmitting the force of the spring as to exert a downward force on the traffic rail when the retarder is actuated.

2. A retarder according to claim 1 wherein the resilient preload means exerts a direct downward force on the traffic rail when the retarder is actuated.