US3498475A - Automatic hydraulic centering device - Google Patents

Description

March 3, 1970 e. w. COPE AUTOMATIC HYDRAULIC CENTERING DEVICE 2 Sheets-Sheet 1 Filed Jan. 7, 1965 In v e n t o r Geoffrey W. C o p 6 his Attorney March 3, 1970 e. w. cops 3,498,475

AUTOMATIC HYDRAULIC CENTERING DEVICE Filed Jan. 7 1966 2 Sheets-Sheet 2 v 20 20 'Il/IIIIIIIIII/Ili/IIIIIIIII11/ FIG. 3

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In v e n to r:

Geoffrey W. Cop e his Attorney United States Patent US. Cl. 213- 11 Claims ABSTRACT on THE DISCLOSURE A device for automatically centering a head of an uncoupled horizontally swingable railway coupler on underlying track, having hydraulically connected master and slave hydraulic units respectively connected to an adjoining truck away from the trucks pivot and acting on the coupler forwardly of the pivot about which the coupler swings horizontally for horizontally swinging the coupler when uncoupled in response to horizonizontal angling of the truck and yieldable means disposed between the coupler and truck and operative when the coupler is coupled for enabling the coupler to swing horizontally independently of the horizontal angling of the truck.

This invention relates to automatic centering devices for railway car couplers.

Automatic couplers, such as now used on railroads and rapid transit lines, are designed to couple automatically with a mating coupler but will only so couple if impacted by the mating coupler within the gathering range of their heads. To follow track curvatures when coupled, a conpler must be capable of swinging horizontally, with the extent of the swing determined by the length of the overhang of the car beyond its trucks and the minimum radius curve the car must negotiate. A coupler can be adapted to couple on straight track by centering it on the centerline of the car and there are a number of devices suitable for the purpose. However, to be coupleable on both straight and curved track, an uncoupled coupler must have its head centered not on the centerline of the car but on that of the underlying track. Approximate centering, within the gathering range of the heads of the couplers being coupled, will sufi'ice, and it is in this sense that the term centering is here used. Unless the couplers intended to be coupled are so centered, not only can they not couple but the coupling impact, instead of being taken through the cars cushioning devices, is taken directly by their ends and damage is almost inevitable. The problem is particularly acute in coupling long freight cars and subway cars.

The primary object of the present invention is to provide a hydraulic centering device for automatically centering an uncoupled coupler on underlying track in position to couple with a mating coupler.

Another object of the invention is to provide an automatic hydraulic coupler centering device which derives its centering action from the horizontal angling of the adjoining truck relative to the car body and translates that angling into horizontal angling or swinging of the coupler in the same direction and to the extend necessary to center its head on the underlying track.

An additional object of the invention is to provide an automatic hydraulic coupler centering device which, While exerting a centering action on the coupler whether it is coupled or uncoupled, permits a coupled coupler to deviate from centered position to accommodate special conditions, such as those experienced on tangent points and reverse curves.

FIGURE 1 is a somewhat diagrammatic plan view of an end portion of a subway car fitted with an embodi- 3,498,475 Patented Mar. 3, 1970 ment of the automatic hydraulic coupler centering device of the present invention;

FIGURE 2 is a side elevational view of the structure of FIGURE 1;

FIGURE 3 is a vertical sectional view on an enlarged scale taken along line 3-3 of FIGURE 2;

FIGURE 4 is a partial plan view of the car end portion of FIGURE 1 showing a second embodiment of the centering device of the present invention;

FIGURE 5 is a partial plan view of the car end portion of FIGURE 1 showing a third embodiment of the centering device of the present invention; and

FIGURE 6 is a diagrammatic plan view on a reduced scale of the structure of FIGURE 1.

Referring now in detail to the drawings in which like reference characters designate like parts, the improved automatic centering device of this invention, While applicable generally to railway car couplers and far more useful than devices for centering a coupler on a cars centerline, is of particular benefit on subway or rapid transit cars and piggyback or other long freight cars having long overhangs. Equally applicable whether a car has a fixed or a cushioned underframe, the improved centering device has been applied for purposes of illustration to a coupler of the type generally used on subway cars.

As typical of couplers with which subway cars are equipped, the illustrated coupler 1 is the automatic hook type coupled disclosed in detail in Cope Patent No. 3,181,708, issued May 4, 1965. The coupler 1 is connected for relative horizontal swinging, angling or pivoting to the cars body, indicated at 2, but, unlike a standard freight car coupler, is so connected through a drawbar 3, which, insofar as this invention is concerned, forms a rearward extension of the couplers shank 4. A head 5 of the coupler, integral with its shank 4, contains a pivoted hook 6 which projects forwardly through the heads flat front or bufling face 7 lying on the couplers coupling line. For enabling the coupler automatically to connect the cars electric and air service lines (not shown) to those of another car, as the cars are mechanically connected, the couplermounts on its head 5 suitable electric and fluid couplings 8 and 9, respectively.

The shank 4 of the coupler 1 is connected for vertical swinging or pivoting to a yoke 10 which slides longitudinally in the drawbar 3 and is cushioned in its longitudinal movements under bufiing and draft forces on the coupler by a rubber or other suitable cushioning unit mounted in the drawbar. At the rear the drawbar 3 is connected by a vertical drawbar pin 12 to an anchor bracket or anchorage 13 fixed to the underside or fixed underframe 14 of the car body 2. Supported at the rear and angleable, swingable or pivotable horizontally on the anchor bracket 13 about a vertical pivot or axis P coincident with the axis of the pivot pin 12, the drawbar 3 is slidably supported at the front on a radial carrier bar 15 fixed to and suspended from the car body 2.

Rearwardly or inwardly of the anchor bracket 13, the car body 2 is mounted on one of a pair of trucks, only the bolster 16 of which is shown. As usual, the adjoining truck is connected to the car body for relative horizontal angling, swinging or pivoting through the bolster 16 by a vertical kingpin 17, the axis of which is the trucks pivotal axis or vertical pivot P When a car is on a curve, its trucks are angled horizontally relative to its body. At that time, the truck pivot P is on the centerline of the track and the centerline of the bolster 16 is substantially on a radius of the curve passing through the pivot. It is this angling of the truck as it follows the curvature of the track that is here used to center the head 5 of the coupler 1 on the part of the track underlying it. Deriving its centering action from the angling of the adjoining truck relative to the car body, the im proved centering device, designated as 18, operatively connects the coupler 1 to the adjoining truck for hydraulically translating horizontal angling of the truck relative to the car body into horizontal angling of the coupler, such that the latters head 5 is centered on underlying track.

The hydraulic centering device 18 is comprised of one or more master or drive cylinder units 19, each mechanically connected to the truck at a distance from the truck pivot P and hydraulically connected to a slave or driven cylinder unit 20 for transmission of force therebetween by the displacement of oil or other suitable liquid. In turn, each slave unit 20 is mechanically connected to the coupler 1 forwardly of its and the drawbars vertical pivot P for applying to the coupler the force transmitted to the slave unit from the related or associated master unit 19. Each master unit 19 conveniently is connected to the bolster 16 or other cross member of the truck and mounted forwardly thereof on the fixed underframe 14 of the car body 2, for relative movement of its cylinder 21 and piston 22 in substantial correspondence with the horizontal angling of the truck relative to the car body. Liquid-connected to the related master unit 19 through suitable tub ing 23, each slave unit 20 is mounted on the underframe 14 and connected either directly to the coupler or to a member, such as the drawbar 3, which swings horizontally in unison with the coupler, for swinging or angling the coupler horizontally in substantial correspondence with the relative or longitudinal axial movement of the slave units cylinder 24 and piston 25.

In the first embodiment in FIGURES 1-3, there are two master cylinder units 19 mounted equidistantly on opposite sides of the centerline of the car and disposed or extending substantially parallel to that centerline in the neutral or at rest position in which the truck is at zero angling, with the longitudinal centerlines of the car and the bolster 16 normal or perpendicular to each other. Thus oifset laterally relative to the truck pivot P each of the preferred master units 19, in order to be both telescoped or compressed and elongated as the bolster turns or angles horizontally in one direction or the other from neutral position, must itself be capable of swinging or angling to a degree dependent upon its lateral offset. For this purpose each master unit is pivotally connected to both the bolster 16 and the car body 2, as by having the opposite ends of its piston rod 26 and cylinder 21 clevised for pivotal connection of one to a bracket 27 on or fixed to the front or confronting side of the bolster and the other to a mounting bracket 28 attached to the underframe 14 of the car body 2, the rod here being connected to the bolster bracket and the cylinder to the car body bracket. To compensate for manufacturing tolerances, the connection 29 between each car body bracket 28 and the related master cylinder unit 19 preferably is adjustable so that the bracket within limits can be shifted either longitudinally or laterally of the body. To accommodate the angling of each master unit 19, the tubing 23 connecting it to the related slave unit 20 can be either flexible tubing or in the main rigid, with a section 30 of flexible, preferably armored, hose in its end portion adjoining the master unit.

As opposed to the master units 19, the slave units 20 are disposed or directed laterally of the car and normal or perpendicular to its longitudial centerline. Each slave unit 20 is connected at one end to a bracket 31 fixed to the underframe 14 and at the other to the coupler 1, the preference being to connect its cylinder 24 to the bracket and the rod 32 of its piston 25 to the coupler. Rather than connect them individually to the coupler 1, the slave rods 32 preferably are connected to and act on the coupler through a centering yoke 33 receiving and having arms 34 laterally embracing or straddling and confronting opposite sides either of the shank 4 or, as illustrated, of hearing plates or pads 35 fixed to and providing flat bearing surfaces on the sides of the drawbar 3, which here forms the shanks rearward extension. Disposed laterally of the car body 2, the centering yoke 33 is open longitudinally thereof to pass the drawbar 3 and also opens either upwardly or downwardly, depending on whether, as convenient, it is applied from below or, as illustrated, above to the drawbar. Instead of directly engaging the bearing plates 35 at the sides of the drawbar 3, the yoke arms 34 embracing those sides preferably are lined with pads 36 of Teflon or like Wear-resistant, lubricious material, the inner faces 37 of which are arcuately convex and spaced slightly more than the embraced width of the drawbar to accommodate the relative angling therebetwee'n.

In this first embodiment in which the master and slave units 19 and 20 are all single-acting units, angling of the bolster 16 out of neutral position as the car negotiates curved track, will compress or telescope the master unit at one side and correspondingly expand or elongate the other master unit. Connected on its liquid side to the liquid side of the related slave cylinder 20 by the tubing 23, the compressed master unit will displace liquid to the slave unit and, by expanding or elongating the latter and projecting its piston rod 32, shift the centering yoke 33 toward the opposite side of the car and, therethrough, swing or angle the coupler 1 toward that side. Since the piston rod 32 of the other slave unit 20 is also connected to the yoke 33, it will be compressed or telescoped by the shifting of the yoke by the first unit and positively displace the excess liquid to the related master unit 19. Subsequent turning or swinging of the bolster 16 back to neutral position, as the car reaches straight track, will re verse this action and return the coupler 1 to a position in which it is centered on the car body 2 as well as on the underlying track.

The above-described centering action serves to center an uncoupled coupler on either curved or straight underlying track in position to couple with a mating coupler and in most cases would reflect and not interfere with the angling of the coupler when coupled. However, under special conditions, as on tangents and reverse curves, a coupled coupler must deviate from the track-centered position in which the centering device 18 would hold it. Accordingly, it is necessary that there be some yieldability in the centering device to accommodate such special conditions of the coupler 1, when coupled, without detriment to the centering of the coupler, when uncoupled, on underlying track. In the first embodiment, the

necessary yieldability is obtained conveniently by making the centering yoke 33 I-l-shaped with side webs 38 connecting extensions 39 of the arms 34 embracing or straddling the drawbar 3, the arm extensions 39 being apertured to fit over and slidably receive the piston rods 32 of the slave units 20. The rods 32 have their ends connected between the arm extensions 39 by a connecting rod 40 of smaller diameter screwed or otherwise connected at its ends thereto and slidably mounting a pair of bushings 41. A relief spring 42 mounted on the sleeve 40 and interposed between the bushings 41, is of a strength to yield to and be compressed by the deviational forces acting under special track conditions on a coupled coupler, but not by the lesser forces initiated at the truck to center the coupler. With the relief spring 42 of such strength, the centering yoke 33 will normally be connected for movement in unison with the rods 32 of the slave cylinders 20 and can move axially relative to the rods whenever required to meet deviational conditions.

The second form of the centering device shown in FIGURE 4 is identical with the first except in its provision for yieldability to meet special or deviational conditions. In this second form the common relief spring 42 of the first has its function performed by a pair of accumulators 43, one connected in the line or tubing 23 between each master unit 19 and its slave unit 20. The centering yoke 33 and the slave piston rods 32 being fixed against relative movement in this form, the ac cumulators 43, to perform their intended function, must in effect be by-passed except under special or deviational conditions and then be adapted to receive the excess liquid occasioned by the deviation in the line at the side to ward which the coupler is swung. Suitably, the accumulators 43 can be of the type having a chamber 44 connected to the liquid line 23 and partly filled with a compressed gas either immiscible with the liquid or, as indicated, separated therefrom by a diaphragm. By predetermining its pressure, the gas may be made to serve as a yieldable relief medium which blocks entry of liquid from the line 23 to the chamber 44 under the forces required to center an uncoupled coupler, but permits such entry under the greater deviational forces. As opposed to the relief spring 42, the centering device employing the accumulators 43 as its relief media, will of course require periodic checking to ensure not only that the gas pressures in the chambers 44 are sufiicientbut also that they are equal under normal conditions, a necessity to avoid biasing of an uncoupled coupler away from center toward a side of lesser pressure.

In the third form shown in FIGUIE 5, the master and slave cylinder units 19 and 20 at one side of the car are dispensed with and the single-acting units at the other side are replaced by double-acting master and slave units 45 and 46, respectively having their corresponding sides connected by a pair of connecting lines or tubes 47. The double-acting master and slave units 45 and 46 have the pistons 22 and 25 and connected piston rods 26 and 32 of a connected master unit 19 and slave unit 20 of the first form. The difference in free cross-sectional area at opposite sides of the piston of each unit is compensated for by connecting thecorresponding sides of the master and slave cylinders and using piston rods of such relative diameter in the two cylinders that the ratios of the free cross-sectional areas of the rod and non-rod sides of the master cylinder to those of the connected sides of the slave cylinder are the same. Deviational movements of a coupled coupler under special track conditions can be accommodated in this double-acting unit form in either of the ways previously described for the single-acting unit form.

The automatic hydraulic centering device 18 is not a universal centering device in the sense that a single set of specifications will apply to its installation on all cars. However, the specifications for a given car are readily calculated. The factors involved in the calculations are indicated in FIGURE 6 in which the coupler 1 and bolster 16 are shown in solid line in the neutral or zero degree angling positions they would occupy on straight track and in dot-and-dash line at maximum angling in the positions they would occupy in centering the head of the coupler on underlying track with the car on a curve of the minimum radius usually found in subway trackage. The factors in determining the specifications for a particular car and the symbols designating them in the figure are as follows:

Maximum angle of bolster on minimum radius track 0 Maximum angle of coupler in centering head on minimum radius track 'y Coupler length from face or coupling line 7 to pivot P for horizontal angling L Longitudinal spacing between coupler pivot P and truck pivot P L Moment arm of master cylinder unit 19 or 45 L Distance of movement of arm L at angle 6 in a direction perpendicular to its central position L Moment arm of slave cylinder unit 20 or 46 L Distance of movement of arm L at angle 7 in a direction perpendicular to its neutral position L Internal free cross-sectional area of master cylinder 21 A Internal free cross-sectional area of slave cylinder Of the above factors, the angles 0 and 'y, the coupler The above ratio being known for a given car and angles of less than 40, such as here involved, having substan tially the ratio of their sines, the moment arms of the master and slave units and the areas of their cylinders in suiting the centering device 18 to a given car, are derived as follows:

Instead of being mounted on a car having a fixed underframe, as in the illustrated embodiment, the coupler with which the centering device 1-8 is to be used, can be mounted in a floating sill of a cushion underframe car, an example of which is shown in my copending application Ser. No. 475,975, filed July 30, 1965, now Patent No. 3,283,916. In such case it usually will be preferred to mount the or each slave cylinder unit 20 or 46 in the floating sill rather than on the fixed underframe. This will require sufiicient flexibility in the liquid line or lines 47 or 23 to accommodate the range of movement of the floating sill relative to the car body but will not otherwise affect the centering unit or the calculation of its specifications for a given installation.

From the above, detailed description it will be apparent that there has been provided an improved automatic coupler centering device which can be applied to any car having automatic couplers and, when so applied, will elfec tively center the head of an uncoupled coupler on underlying track in position to couple with a mating coupler and, without disengagement from the coupler, permit the deviational movements of a coupled coupler required to meet special track conditions. It should be understood that the described and disclosed embodiments are merely exemplary of the invention and that all modifications are intended to be included that do not depart from the spirit of the invention.

Having described my invention, I claim:

1. In a railway car having a coupler swingable horizontally about a pivot and a truck angleable horizontally about a pivot spaced rearwardly from the coupler pivot, an automatic coupler centering device comprising liquidconnected master and slave hydraulic means respectively connected to said truck away from the truck pivot for response to horizontal angling thereof and acting on said coupler forwardly of the coupler pivot for centering a head of said coupler when uncoupled on underlying track by horizontally swinging said coupler in response to said horizontal angling, and yieldable means disposed between said coupler and truck and operative When said coupler is coupled for enabling said coupled coupler to swing horizontally independently of horizontal angling of said truc 2. In a railway car according to claim 1 wherein the centering device includes means connected to the coupler forwardly of the pivot thereof and normally movable horizontally substantially therewith, and yieldable means for enabling said coupler when coupled to swing horizontally independently of horizontal angling of said truck, the slave means are connected to and act on the coupler through said connected means, and said yieldable means are in the connection of the slave means to said connected means.

3. In a railway car according to claim 2 wherein the yieldable means are relief spring means acting between said connected means and said slave means.

4. In a railway car according to claim 2 wherein the yieldable means are accumulator means in the liquid connection between said master and slave means.

*5. In a railway car according to claim 4 wherein the accumulator means are maintained under a gaseous pressure sufficient to render them inoperative except when the coupler is coupled.

6. In a railway car according to claim 1 wherein the master and slave means are each cylinder means, and the master cylinder means are pivotally connected to both the body and the truck.

7. In a railway car according to claim 6 wherein the master and slave cylinder means are disposed respectively longitudinally and laterally of the car body.

8. In a railway car according to claim 7 wherein each slave cylinder means has a cylinder fixed to a part of an underframe of the car body and a piston connected through the connected means to the coupler.

9. In a railway car according to claim 8 wherein the connected means is a yoke embracing sides of the coupler.

10. In a railway car according to claim 9 wherein the yoke has arms embracing the sides of the coupler, and the arms are lined with wear-resistant lubricious pads having arcuately convex faces confronting the coupler sides.

11. A coupler centering device for a coupler swingably mounted on a frame of a railway car having a wheeled truck traveling on track, said device comprising fluid pressure responsive means disposed between said coupler and frame for swinging said coupler when uncoupled laterally relative to the longitudinal center line of said car, fluid motor means, means providing fluid communication between said fluid motor means and said fluid pressure responsive means, said fluid motor means being disposed between said truck and frame to sense the curvature of said track as said truck turns thereon relative to said longitudinal center line and to generate a fluid pressure change in said fluid motor means which corresponds to the angular position of said truck relative to said longitudinal center line so that said fluid pressure responsive means responds thereto and swings said coupler when uncoupled to a position in which a head of said coupler is substantially centered with respect to the underlying track, and yieldable means disposed between said coupler and truck and operative when said coupler is coupled for enabling said coupled coupler to swing laterally relative to said longitudinal center line independently of said relative angular position of said truck.

References Cited UNITED STATES PATENTS 2,841,293 7/1958 Spencer 213-43 3,217,897 11/1965 Peterson 213-43 3,249,240 5/ 1966 Empson 213-43 3,255,891 6/1966 Cope 213-19 DRAYTON E. HOFFMAN, Primary Examiner US. 01. X.R. 213 19, 2 0

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