US3403752A - Railway car retarder braking apparatus - Google Patents

Description

Oct. 1, 1968 E. o. GARRETT, JR., ET 3,403,752

RAILWAY CAR RETARDER BRAKING APPARATUS 2 Sheets-Sheet l &

A E m u m bh Filed Feb. 24, 1967 Oct. 1, 1968 E. o. GARRETT, JR., ETAL 3,403,752

RAILWAY CAR RETARDER BRAKING APPARATUS Filed Feb. 24, 1967 2 Sheets-Sheet 2 Edward 0. Garrecfi: and Pei?! M AOble.

msnz HZTOEA/Ef United States Patent 3,403,752 RAILWAY CAR RETARDER BRAKING APPARATUS Edward 0. Garrett, In, Penn Hills Township, Allegheny County, and Peter M. Noble, Valencia, Pa., assignors to Westinghouse Air Brake Company, Swissvale, Pa.,

a corporation of Pennsylvania Filed Feb. 24, U67, Ser. No. 618,417 Claims. (Cl. 188-62) ABSTRACT OF THE DISCLOSURE A Weight proportional car retarder having an operating unit movable between braking and nonabraking positions including a modularly constructed assembly having a unitized closed hydraulic operating mechanism for selectively activating the retarder either to effect a braking action on the wheels of a traversing car in proportion to its weight or to allow free passage of the car wheels.

Our invention relates to railway braking apparatus and more particularly to the construction of a modular type of hydraulic actuating assemblage having a unitized operating mechanism for the operating units of weight proportional car retarders.

Recently, inert type of car retarders have been successfully employed in small and medium sized railway classification yards for the purpose of contolling the speed of moving cars undergoing classification. For example, it has been found advantageous to utilize inert car retarders in such limited capacity handling applications for group and hump car retarder operations since this type of retarder exerts and removes approximately the same velocity head from all cars irrespective of their weight. However, many of the previous inert car retarders and particularly their operating mechanisms and control systems are generally not acceptable for such usage since they employ open hydraulic circuits which are not only expensive, complex, difficult to maintain and replace, but also are sluggish or too slow in operation. Accordingly, in order to enjoy and achieve universal usage in these classification yards as well as in other applications, these weight proportional car retarders must be provided with suitable control systems and, more particularly, with appropriate operating aparatus for moving the car retarder between its non-braking and braking positions. Therefore, considerable effort and particular attention have been directed to the applicability of an air-assisted hydraulic actuated retarder arrangement since the use of an air-assisted control system permits the car retarder to :be actuated by means of a closed hydraulic operating mechanism. It has been found that a closed hydraulic circuit results in numerous advancements which improve the efficiency and overall operation of a weight proportional car retarder. For example, closed hydraulic apparatus is readily susceptible to modular construction which not only completely eliminates the necessity of extensive piping but also materially reduces the number of components heretofore required by the previous types of open hydraulic control apparatus. Accordingly, a more compact, less complex and less expensive retarder arrangement may be realized and obtained by constructing unitized hydraulic apparatus. Further, a modular type of construction results in maximum accessibility to the various components and elements so that replacement, maintenance, and adjustment may be quickly and easily performed. In addition, the utilization of a closed hydraulic operating mechanism promotes 'faster retarder operation due to improved response time, provides maximum protection to the components due to modular fabrication, and reduces the chances of ICC leakage and loss of pressure due to elimination of extensive field piping.

Accordingly, it is an object of our invention to employ a new and improved actuating assembly and operating mechanism for a hydraulically-actuated pneumaticallypowered electrically-controlled system for a weight proportional car retarder.

A further object of our invention is to provide a modular type of hydraulic actuating assembly for weight proportional car retarders.

Another object of our invention is to povide a new and improved unitized hydraulic operating mechanism for the operating units of a car retarder.

Still another object of our invention is to provide a unique modularly constructed closed hydraulic assembly for the control system of a weight proportional car retarder.

Still yet another object object of our invention is to provide a simple, compact and economical unitized hydraulic operating mechanism for a weight proportional car retarder.

Yet another object of our invention is to provide a weight proportional car retarder with modular type of closed hydraulic actuating apparatus which is easy to replace, simple to maintain and facile to adjust.

Briefly, the objects of our invention are achieved by providing a modularly constructed closed hydraulic actuating assembly for a weight proportional car retarder having operating units including a pair of levers and frictional braking elements mounted on opposite sides of the track rail. More specifically, our invention has been suitably adapted for use and in conjunction with a retarder control system shown and claimed in our copending application for Letters Patent of the United States Ser. No. 560,178, filed June 24, 1966, for Railway Car Retarder Control Systems, now Patent No. 3,340,963, which is assigned to the assignee of our present application. In practice, the assembly includes a unitized hydraulic operating mechanism having a hydraulic ram, a pneumatic-hydraulic transducer and a solenoid control valve which is suitably disposed between the cross-tie and one of the pair of levers of the operating unit on the side of the track rail. The cylinder of the hydraulic ram is pivotally connected by a journal pin to a ram base member. The ram base member is fixedly secured to an adjustably supporting arrangement including a flat base plate adjusta'bly secured by a plurality of fasteners and tenon washer to a pair of angle irons which are rigidly connected to opposite sides of the cross tie. The piston of the hydraulic ram is pivotally connected by a journal pin to one of the pair of levers. The pneumatic-hydraulic transducer is securely fastened to the cylinder of the hydraulic ram by means of a T-shaped bracket and a pair of U-bolts. The solenoid control valve is connected between the pneumatic-hydraulic transducer and the hydraulic ram by conduit fittings which also provide fluid communication between the pneumatic-hydraulic transducer and the hydraulic ram for causing the retarder to assume its braking position or for allowing the retarder to assume its non-braking 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:

FIG. 1 is a partial vertical sectional view of one of the operating units of a weight proportional car retarder constructed in accordance with the present invention.

FIG. 2 is a detached side elevational view of the modularly constructed closed hydraulic actuating assembly and unitized operating mechanism embodying the present invention.

FIG. 3 is a top view of the modularly constructed closed hydraulic actuating assembly and unitized operating mechanism embodying the present invention.

Referring to the drawings, wherein like parts are indicated by like reference numerals, and in particular to FIG. 1, there is shown a sectionalized elevational view of the weight proportional car retarder in its braking position, and more specifically, there is illustrated one of the plurality of operating units which are suitably disposed at spaced intervals along the rail. However, for the purpose of convenience, only the details of one operating unit will be described since the remaining operating units are similar and substantially identical in construction and operation. In actual practice it has been found that only five operating units are required for a car retarder having a length of approximately sixteen (16) feet for effectively and efiiciently handling even the heaviest railway car in use at the present time. However, it is understood that the number of operating units per retarder and the overall retarder control system may be designed and constructed to accommodate a greater or lesser number of retarder Operating units in accordance with the needs of any particular situation.

As shown in FIG. 1, the reference character 1 designates one of the traffic or track rails of a stretch of railway track over which the Wheels of railway Vehicles pass. The rail 1 is preferably supported and carried by the suitably spaced operating units each of which consists of a pair of substantially identical levers 2A and 2B, of the general known type, disposed laterally on opposite sides of the rail 1. The operating levers 2A and 2B are of one-piece cast construction and have their inside bottom portions securely held in suitable relationship by means of a through-type tie bolt 3. As shown, the upper surface of the inside bottom portions of each of the levers engages the flange of the rail 1 while the lower surface of the inside bottom portions of each of the levers includes a contact rod, not characterized, normally resting on a thrust channel or bearing plate 4 which is suitably mounted on cross ties 5, when the car retarder is in its braking position and no vehicle is being retarded or when the car retarder is in its non-braking position. The inside top portion of each lever has suitably secured thereto, in any suitable manner, the braking elements of the car retarder. These braking elements may consist of conventional braking rails or as shown brake beams 6 and removable brake shoes 7 which are adapted to frictionally engage the Opposite sides of the car wheels when the retarder is in its braking position.

As is readily evident from viewing FIG. 2 of the abovementioned copending application, each of the levers of each operating unit is suitably supported at preselected points spaced from the rail 1 for permitting free pivotal movement as required for retardation of the cars and as will be described hereinafter. For example, in actual practice the underside of the outside end of lever 2B is pivotally mounted on a suitable supporting stand or member, see FIG. 2 of our copending application, while the lever 2A is pivotally connected to a modularly constructed hydraulic actuating assembly, generally characterized by HA. The pivotal supporting stand for lever 2B has preferably a predetermined fixed height and is appropriately connected to a suitable tie plate which may be secured and mounted to the top of cross-tie 5. As shown in FIG. 1, the hydraulic actuating assembly HA is arranged to maintain the braking elements in the desired position, namely, at substantially the same elevational height for causing retardation. While the hydraulic actuating assembly HA is shown pivotally connected intermediate the ends of the lever 2A, it is readily understood that the assembly may be positioned at any point along the entire length of cross-tie 5 and may even be pivotally connected to the outer extremity of the lever 2A when it is desired to increase and maximize the amount of braking force applied to the opposite sides of a traversing car wheel.

As shown, the hydraulic actuating assembly HA is suitably disposed on the cross-tie 5. For example, as shown in FIG. 1, the cross-tie 5 is provided with a rectangular recessed portion 10 for suitably accommodating and supporting the hydraulic actuating assembly HA. A pair of angle irons 11A and 11B are rigidly secured to the opposite sides of the cross-tie 5 byineans of .a pair of stud bolts 12 which pass through the .vertical legs of the angle irons and the cross-tie 5. The horizontal leg of each angle iron 11A and 11B are disposed in alignment with the upper planar surface of the rectangular recess 10. The horizontal legs are each provided with a pair of elongated slots for accommodating suitable fastening means, which will be presently described. A fiat square base plate 13 is shown disposed in face-to-face relationship with the upper surface of the recess 10 and the upper surfaces of the horizontally extending arms of angle irons 11A and 11B. The square base plate 13 includes a plurality of enlarged holes or apertures 14 located in its respective four corners. The enlarged apertures 14 are adapted to receive suitable slotted tenon plugs or washers having a sleeve portion disposed within the enlarged apertures 14 and aflange portion abutting the upper surface of base plate 13. The sleeve portions of the plugs 15 and the enlarged apertures 14 are so proportioned and dimensioned that a preselected amount of free play or movement exists therebetween so that relative adjustment and lateral translation may occur between base plate 13 and angle irons 11A and 11B. For example, as viewed in FIG. 1 the base plate 13 may be selectively moved toward or away from the rail 1, or as viewed in FIG. 2 the base plate 13 may be shifted toward the left or right for centering and positioning the entire hydraulic actuating assembly relative to the lever 2A. The base plate 13 is securely held in fixed relationship with the angle irons 11A and 11B by means of suitable bolts 17 which may be tightened after proper adjustments have been made. As is readily apparent, an additional amount of movement of the base plate 13 is also permitted by the longitudinal slots in angle irons 11A and 11B so that the entire assembly may be further moved normally to the rail 1, as desired.

As shown, the unitized operating mechanism including a ram base member 18 is centrally located on the upper surface of base plate 13 and is securely held by means of a plurality of cap screws 20. In viewing FIG. 2, it will be noted that base member 18 includes an apertured lug 19 which is provided with a self-aligning spherical bearing 21, the purpose of which will be described hereinafter. The lug 19 cooperates with the lower portion of the hydraulic ram 22 and provides a pivot point for the entire mechanism. For example, the lower portion of the cylinder 23 of the hydraulic ram 22 is bifurcated and the lug 19 is arranged to fit between the two branches of the bifurcation. Each branch is provided with suitable openings 24 in which a pivot pin or shaft 25 is disposed in horizontal parallel relationship with the running rail 1. A suitable washer 26 is disposed between each side of the lug 19 and the adjacent surfaces of each branch of the lower portion of cylinder 23. The ends of the pivot shaft 25 extend outwardly from the two branches as shown in FIG. 2, and cotter pins prevent displacement of the shaft therefrom. As previously mentioned, the hydraulic ram 22 includes a piston member 28 which cooperates with the lever 2A to permit elevationally pivotal movement therewith. As shown, the upper portion of the piston 28 includes an upstanding lug member 29 which is suitably disposed intermediate the ends of the lever 2A. As previously noted, the piston 28 and lover 2A may be connected at various points along the longitudinal axis of lever 2A so that the moment arm and braking action may be increased or decreased, as desired. The lug 29 is provided with a suitable opening or aperture for accommodab ing a self-aligning spherical bearing 30 similar to that of lug 19 so that pivotal movement as well as a limited amount of rotational movement may exist between lever 2A and the piston 28. As shown, the lug 29 is securely fastened to the lever 2A by means of a suitable bolt 31 passing therethrough. Accordingly, the spherical bearings 21 and 30 provide a rotational pivotal engagement to exist between the supporting base and the lever 2A so that a limited amount of angular variation may exist therebetween, and in actual practice this arrangement allows an eight -(8) degree excursion from the vertical center line of the hydraulic ram.

As will be apparent from the following discussion, the hydraulic ram 22 and particularly its cylinder provides the central support for the remaining elements of the closed hydraulic operating mechanism. As shown, one end of an elongated T-shaped member or bracket 32 is rigidly secured to the cylinder of the hydraulic ram 22 by means of a U-bolt 33. A pair of elongated contacting blocks 34 are suitably secured to the cros'spiece or head of the T- shaped bracket 32, for example, by welding, for conveniently positioning and providing additional 'bean'ng surfaces between the cylinder and bracket.

A pneumatic-hydraulic transducer 35 is suitably secured to the other end of the elongated T-shaped bracket 32 by means of U-bolt 36. The pneumatic-hydraulic cylinder 35 preferably includes an outer metallic cylindrical body and an inner flexible bag or resilient diaphragm, not characterized, which divides and separates the closed hydraulic circuit from the open pneumatic circuit of the retarder control system. As shown, a threaded nipple 38 and a pipe union 39 are connected to one end of the transducer 35 for providing a convenient coupling or connection to a suitable low pressure pneumatic supply, such as, 100 p.s.i. source. The other end of the pneumatichydraulic transducer 35 is connected to a pipe T 40 which form part of the closed hydraulic circuit. One side of the T 40 is threadably connected to a threaded reducing adapter 41 and in turn to a suitable quick disconnect valve fitting 42 which is employed for the purpose of charging the hydraulic circuit and providing the necessary amount of hydraulic fluid for proper operation. A dust cap 43 covers the valve fitting 42 for preventing moisture and foreign particles from entering and accumulating in valve fitting 42 during operation. The other side of the T 40 is connected by a threaded nipple 44 to one side of an electrically operated solenoid control valve 45. The other side of the solenoid control valve is hydraulically coupled to the hydraulic ram 22 through means of high pressure street elbow 46 and threaded nipple 47. As shown, a suitable bleeder valve 48 is threadably coupled to the elbow 46 for conveniently providing that the hydraulic circuit may be readily purged of air and bled of excess hydraulic fluid. It will be appreciated, that the various fittings not only hydraulically interconnect the Peumatichydraulic transducer 35 to the hydraulic ram 22 but also rigidly hold and support the solenoid control valve in its position, as shown in the drawings. Further, such an arrangement not only produces a firm and compact structure but also results in a small capacity short length hydraulic circuit which greatly reduces and substantially eliminates problems due to sponginess and possible compressibility normally inherent in large and long hydraulic systems.

The solenoid control valve 45 is preferably a normally closed two-way two-position spool valve which may be of a type manufactured by Waterman Hydraulics Corporation. As is readily evident, the solenoid control valve 45 functions to establish various fluid directional paths between the pneumatic hydraulic transducers 35 and the hydraulic ram 22 so that the retarder may be controlled in accordance therewith. Preferably, this valve includes a D.C. operated solenoid coil which when energized establishes a bidirectional path between the transducer 35 and the hydraulic ram 22 and also includes a return spring which establishes a unidirectional path from the transducer 35 to the hydraulic ram 22 when the solenoid coil is deenergized. A clamp 49 securely holds the electrical cable 50 which supplies electrical power to the solenoid coil from a suitable source of direct current voltage. A cover plate 52 is suitably attached to the valve 45 for precluding the accumulation of dust, dirt and grease on the valve and preventing possible damage to the valve.

Accordingly, the resultant structure provides a modular type of hydraulic actuating assembly having a unitized operating mechanism which is easily positioned and adjusted for operation in conjunction with a weight proportional car retarder. It will be appreciated that in case of hydraulic failure or physical damage which prevents normal operation, either the entire modularly constructed assembly or simply the unitized operating mechanism may be readily removed and quickly replaced by the appropriate apparatus. In viewing FIG. 2, it will readily be noted that the modular assembly is so arranged and proportioned that all of the components are within the dimensional confines of the base plate 13 which insures maximum component protection without the need and necessity of special protection housing or other covering apparatus. Further, as previously mentioned, vertical alignment between the lever and supporting base is readily performed due to the numerous positions offered by the adjustable tenon plug arrangement existing between the base plate and angle irons. Further, by utilizing self-aligning spherical hearings in conjunction with the pivotal connections the possibility of undue stresses and strains is prevented from being exerted on the unitized hydraulic operating mechanism as well as on the other structure constituting the weight proportional car retarder.

In describing the operation of the railway car retarder, it will be assumed that the apparatus is in the position as shown in FIG. 1 wherein the piston 28 of the hydraulic ram 22 is fully extended so that the brake shoes 7 are spaced apart a distance less than the width of the car Wheels traversing the retarder. It will be noted that the distance between the brake shoes 7 is periodically checked and maintained to compensate for wear so that effective braking may be exerted on wheels of a car traversing the retarder. Let us now assume that all the necessary adjustments have been performed and that the entire retarder is operating properly so that when a car enters, the wheels will engage the brake shoes 7 and attempt to force the levers 2A and 2B apart. However, since lateral movement of the levers with respect to the rail 1 is prevented, the levers will pivot upwardly about their respective fulcrum points so that the rail 1 and the car wheel are raised upwardly a distance dependent upon both the spacing of brake shoes and the moment arm of each respective lever. Since the raising of the rail 1 lifts the car wheel, the weight of the car, in turn, operates through the rail 1 to exert a force through the levers and in turn to the brake shoes 7 to the opposite sides of the car wheel 4 for effecting a frictional braking action thereon in proportion to the weight of the railway car. Thus, the amount of elfective braking applied to any particular car traversing the retarder is proportionally dependent upon the weight of the car and accordingly the retarder exerts and removes approximately the same velocity head for all cars.

Let us now assume that it is now desirous to permit a railway vehicle to freely pass through the retarder, for example, either for the purpose of withdrawal in skate retarder applications or because the speed of an approaching railway vehicle is at or below a preselected com.- puted value which will allow it to reach its destination in group or hump applications. Under this condition, it is simply necessary to exercise a controlling action wherein the D.C. control valve 45 is activated by energizing its solenoid coil. The energization of the solenoid control valve '45 establishes a bidirectional communication path between the transducer 35 and the hydraulic ram 22 so that the fluid locked within the hydraulic ram 22 is permitted to return to the pneumatic-hydraulic transducer 35. Accordingly, the unlocking of the fluid within the ram permits the piston 28 to rapidly descend under the weight of the car wheel and forces the levers and the brake shoes to become fully open so that the retarder assumes its non-braking position. It will be noted that the piston 28 becomes f-ully contracted or compressed in approximately one-third of a second so that in actual practice a snapaction opening is realized. The piston 28 will remain fully contracted and the retarder will remain in its non-braking position even after the withdrawal or passage of the railway vehicle since, as mentioned in the above-copending application, the open pneumatic circuit is vented to the atmosphere at this time, and the entire control system is in equilibrium.

It will be noted that excessive wear and repeated braking may result in misalignment of the hydraulic ram. However, no excessive damaging forces are exerted on the various elements of the braking apparatus under such an adverse condition due to the self-aligning qualities provided by the spherical bearings.

In order to restore the brake shoes and levers to their braking positions, it is simply necessary to deenergize the solenoid control valve so that a fluid communication path is established from the transducer to the hydraulic ram 22. Under this condition, the hydraulic fluid is forced into the cylinder wherein piston 28 becomes fully extended so that the lever 2A is raised and the spacing between brake shoes 7 again becomes less than the width of a car wheel traversing the retarder. Since the hydraulic fluid is locked within the cylinder 23, the car retarder will remain in its braking position until the solenoid control valve is again energized.

From the foregoing it will be noted that the present invention provides a novel modularly constructed hydraulic actuating assembly and unitized operating mechanism for controlling a weight proportional car retarder wherein a braking force may be applied to the opposite sides of of the car wheel traversing the retarder in proportion to the weight of the car or may allow free passage of a railway car through the retarder.

While the subject hydraulic control apparatus and car retarder have been described in relation to classification yards, it is readily understood that the present invention may also be employed in car dumper applications as well as in other environmental surroundings having need of our 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 modification and changes can be made in the present described invention and therefore it is understood that all changes, equivalents and modifications within the spirit and scope of the invention are here meant to be included in the appended claims.

Having thus described our invention, what we claim is:

1. A modularly constructed hydraulic actuating assembly for a weight proportional car retarder having a pair of levers positioned on opposite sides of a track rail and pivotally mounted on a cross-tie, comprising an adjustable supporting means mounted on the cross-tie, a unitized operating mechanism having a hydraulic ram having a cylinder connected to said supporting means and having a piston connected to one of said levers and movable between a first braking and a second non-braking position, a pneumatic-hydraulic transducer fixedly secured to the cylinder of said hydraulic ram, and an electrically operated control valve hydraulically connected between said hydraulic ram and said pneumatic-hydraulic transducer for preventing said piston from moving from its first braking position when said control valve is deenergized and for permitting said piston to assume its second nonbraking position when said control valve is energized.

2. A modularly constructed hydraulic actuating assembly as defined in claim 1, wherein said adjustable supporting means includes a pair of angle irons fixedly secured to the sides of the cross-tie and a base plate.

having a plurality of apertures for accommodating a plurality of fastening means.

3. A modularly constructed hydraulic actuating assembly as defined in claim 2, wherein each of said fastening means includes a nut and bolt, and a slotted tenon washer having a flange and a sleeve portion cooperating with said base plate apertures for relatively'positioning said base plate with respect to said angle irons.

4. A modularly constructed hydraulic actuating assembly as defined in claim 1, wherein a T-shaped bracket and a pair of U-bolis are rigidly connected from said pneumatic-hydraulic transducer to said hydraulic ram.

5. A modularly constructed hydraulic actuating assembly as defined in claim 1, wherein a first pivotal rotary movement joint interconnects said cylinder to said support means and a second pivotal rotary movement joint interconnects said piston to said one lever for allowing limited rotational motion therebetween.

6. A modularly constructed hydraulic actuating assembly as defined in claim 5, wherein said first and said second pivotal rotary movement joints each include a selfaligning spherical bearing.

7. In a railway braking apparatus having a track rail, a pair of levers pivotally mounted on a cross-tie and positioned on opposite sides of the rail, a wheel engaging braking portion carried by each of the levers and positioned parallel to the rail, a modularly constructed actuating means including a support means positioned on one side of the rail and fixedly secured to the cross-tie, a hydraulic ram connected between said support means and one of said pair of levers, a pneumatic-hydraulic transducer supported by said hydraulic ram, and an electrically operated solenoid control valve connected between said hydraulic ram and said pneumatic-hydraulic transducer for causing said hydraulic ram either to become fully extended for effecting a braking action on car wheels traversing the braking apparatus or to become fully contracted for allowing free passage of car wheels traversing the braking apparatus.

8. A railway braking apparatus as defined in claim 7, wherein said support means includes a pair of L-shaped angle irons each having one leg secured to the sides of the cross-tie by through studs and having the other leg secured to a base plate through a plurality of adjustable connections including a bolt and nut and a sleeved washer.

9. A railway braking apparatus as defined in claim 7, wherein rotary journal bearings interconnect said hydraulic ram to said support means and said one lever for permitting a limited amount of rotational movement therebetween.

10. A railway braking apparatus as defined in claim 7, wherein a T-shaped bracket anda pair of U-shaped *bolts securely interconnect said pneumatic-hydraulic transducer to said hydraulic ram and said solenoid control valve is connected and supported between said hydraulic ram and said pneumatic-hydraulic transducer by interconnecting hydraulic fittings.

References Cited UNITED STATES PATENTS 3,200,245 8/1965 Brown 188--62 X 3,209,865 10/1965 Wynn 18862 3,273,672 9/1966 Creedle et al. 188-62 DUANE A. REGER, Primary Examiner.

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