An articulated coupling arrangement

Abstract: An articulated coupling arrangement for connecting adjacent ends of a pair of railway cars a female member (1) defines a recess (4). A male member (3) adapted to be inserted in the recess carries an articulated coupling (39) having portions (28) projecting on either side to be received within recesses (7) defined in the female member (1) the projecting portions (28) comprise portions of a shaft (2) which is releasably connected to the articulated coupling (39) thus facilitating maintenance of the coupling.

Description: THIS INVENTION relates to an articulated coupling arrangement used to connect adjacent ends of a pair of railway cars together in a semi-permanent manner. It is known for standard couplers to be used to connect adjacent ends of railway cars together. It is recognised that such couplers will be required to serve a number of functions. For example, standard couplers are used to facilitate connecting and inter-connecting individual cars to and from, respectively, a train while enabling such individual cars to negotiate the curved and hilly portions of the track. In the railway industry it has been recognised that a number of advantages can be achieved by the inter-connection of a number of railway cars to form a semi-permanent unit. This has been particularly the situation where such cars are designed for use in what is referred to as "piggy-back" service. Semi-permanent units may be used when cargo to be transported is either brought to or removed from, respectively, predetermined central locations. This cargo is frequently in the form of containers which can be transferred to and from a road vehicle, such as an articulated lorry or truck, or large containers which are used to ship cargo in ocean-going vessels. The individual cars which have been connected together in this semi-permanent manner may be known as a "Five-Pack" or a "Ten-Pack" unit, depending upon the number of cars present. Except at the outer most ends of each such unit, the use of standard couplers discussed above is not required. Because of their dedicated service, the separation of the cars of these units will occur only when maintenance must be carried out on an individual coupler component or on other critical components on a railway car forming part of the unit, which requires that car to be removed from the unit on a temporary basis. With the extensive use of such semi-permanent coupling arrangements it has been found that it is of critical importance for the components of the two interconnecting couplers to be such that there is substantially no play or slack in the coupler. This no-play or slack-free requirement enables the detrimental effects of impact forces, such as those encountered during normal or shunting operation of the train, to be reduced to an acceptable level. In this manner the damage incurred by the cargo and/or the railway equipment can be held to an absolute minimum. This is important in view of the ever increasing loads carried by railway cars and trains. US-A-5042393 discloses an articulated coupling arrangement for connecting adjacent ends of a pair of railway cars, the articulated coupling comprising a female member defining a recess and a male member adapted to be inserted in the recess, means being provided to connect the male member and the female member, the male member carrying an articulated coupling having portions projecting on either side of the articulated coupling, the projecting portions being received and retained within co-operating recesses provided in the female member. EP-A-456 222 shows an articulated coupling having a shaft member of such a design that certain requirements are not met. The drawbacks are obviated by a design as set forth in claim 1. The present invention seeks to provide an improved coupling of a semi-permanent nature which is substantially slack-free. This purpose is achieved by means of the features of claim 1. In accordance with the invention the projecting portions comprise portions of a shaft which is releasably connected to the articulated coupling. The shaft, in preferred embodiments, is retained within the co-operating recesses in a totally slack-free manner, but the preferred coupling is such that it may be dis-assembled in a straightforward manner when it is desired to separate the railway cars. Preferably the articulated coupling carried by the male connection member comprises a ball received within a part spherical cavity defined by the projecting portion, the ball defining a bore which receives the central portion of the shaft. Parts of the shaft project on each side of the ball and are received in the recesses defined by the female member. The movement of the ball relative to the male connection member provides the necessary freedom of movement between the two parts of the articulated coupling. This enables the rest of the coupling to be made in a "tight" and "play-free" manner. Preferably means are provided to secure the shaft to the ball. This ensures a rigid connection between the shaft and the ball at all times. For example, the central portion of the shaft may be tapered and the bore may be correspondingly tapered, so that the central portion of the shaft is a tight fit within the bore. In a preferred embodiment the central portion of the shaft and the bore are provided with co-operating means to prevent rotation of the shaft relative to the ball, the cooperating means comprising a projection and a recess adapted to receive the projection. In one embodiment the shaft may be provided with a projection, such as a key partly received in a recess formed in the shaft, the key thus having a part which projects radially from the shaft, the radially extending part of the key being received within a key-way or recess provided for that purpose in the wall of the bore. Alternatively the wall of the bore may define an inwardly directed rib or projection, and a channel or recess to receive that rib or projection may be provided in the central portion of the shaft. Conveniently clamping means are provided, mounted on the parts of the shaft which project from either side of the bore in the ball, the clamping means engaging either side of the ball to prevent axial movement of the shaft relative to the ball. The clamping means may be secured to the shaft in any convenient way, but preferably each clamping means comprise a clamping element having a face adapted to engage the ball and having a portion defining an inclined face to be inserted into a recess defining a correspondingly inclined face, means being provided to urge the clamping element into a clamping position with the inclined face on the clamping element abutting the inclined face on the recess. It is to be understood that as the clamping element is put into position, the inclined face formed on the clamping element engages the inclined face in the recess, thus urging the clamping member laterally into the clamping position. Preferably wedging means are provided adapted to retain the projecting portions of the shaft in position in the recesses provided to receive and retain those projecting portions of the shaft. Each wedging means may comprise a wedge element having an inclined face adapted to engage a flat face defined on the shaft to clamp the shaft in position. Preferably the shaft is provided with terminal extensions, each defining a flat face and a threaded bore in the free end thereof to facilitate positioning of the shaft during assembly of the coupling. The invention also provides for use with an articulated coupling as described above, the shaft comprising a central portion engageable in a bore in the ball of the coupling, the central portion carrying means for preventing rotation of the ball relative to the central portion, the central portion being disposed between two extending end portions each presenting a substantially flat face for engagement with a wedge member and each having means to cooperate with clamping means to clamp the shaft against axial movement relative to the ball. In using embodiments of the invention, the shaft, which is a part of the coupling that is susceptible to damage and to wear may readily be removed and replaced. In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE 1 is an exploded view of a semi-permanent articulated coupling in accordance with the invention, FIGURE 2 is a side elevational view with part shown in section and part shown in phantom of a removable shaft member of a bearing assembly portion of the coupling, FIGURE 3 is a vertical sectional view of a ball portion of the bearing assembly, FIGURE 4 is a side elevational view of the ball portion of the bearing assembly, FIGURE 5 is a top plan view of a clamping element, FIGURE 6 is a vertical sectional view of the clamping element of Figure 5, FIGURE 7 is an end elevational view of the clamping element of Figures 5 and 6, and FIGURE 8 is a partial sectional view taken on the line A-A of Figure 2 illustrating part of the shaft member. Referring to the drawings a semi-permanent coupling comprises a female connection member 1 which defines a recess, the recess defining portions adapted to receive the opposed ends of a substantially horizontal shaft 2 and also defining a portion to receive a male connection member 3, the male connection member 3 carrying an articulated coupling which engages the shaft 2. The female connection member 1 which may be an appropriate casting, is adapted to be connected at one end (the rear end) to a railway car. The other end (the front end) of the casting defines a recess 4 which is open to the front of the casting and to the top of the casting. Each side wall of the recess 4 is further recessed with supplementary lateral recesses 5,5' which are open to the two lateral sides of the female connection member 1. The recesses 5,5' are mirror images, and thus only the recess 5 will be described. The recess 5 comprises an initial vertical portion between two parallel walls, the wall 6 facing towards the front and an opposed wall (not visible in the figure) facing towards the rear of the connection member 1. The opposed wall is foreshortened to define a forwardly extending part cylindrical extension 7 of the recess 5 adapted to receive part of the shaft 2 as will be described hereinafter. The supplementary lateral recess 5 has a base 8 provided with a centrally located downwardly extending threaded bore 9. A cover member 10 is provided which can be mounted on top of the recess 3 to close off the recess 3 and the supplementary lateral recesses 5,5', the cover 10 being provided with apertures 11,12 through which bolts (not shown) can pass to engage threaded bores 13,14 provided on the female member 1. Each supplementary lateral recess 5,5' is adapted to receive a wedge assembly 15,15' adapted to engage the shaft 2 as will be described below. The wedge assemblies are identical and thus only the wedge assembly 15 will be described. The wedge assembly 15 comprises a wedge element 16 having a substantially vertical rear face 17 and an inclined front face 18. A vertical bore 19 passes through the wedge element. A bolt 20 is provided having a head 21 at its upper end. The bolt passes through a resilient element 22 which may comprise a spring or a Belville washer, through the bore 19 provided in the wedge element 16 and through a tubular spacer element 23, the threaded lower end 24 of the bolt then engaging the threaded bore 9 provided in the base 8 of the recess 5. The bolt 20 may be tightened thus forcing the wedge elements 16 downwardly with a resilient force. The removable shaft member is symmetrically about its mid point, thus, in the following description, only one end of the shaft will be described in detail, but it is to be appreciated that the other end of the shaft is effectively a mirror-image of the end that is described. The shaft 2 has a central portion 24 of substantially cylindrical form, of a predetermined length which is preferably between 19.30 cms (7.60 inches) and 19.81 cms (7.80 inches). The diameter of the centre portion 24 adjacent one end is slightly less than the diameter adjacent the other end, so that there is a predetermined taper on the outer surface of the centre portion 24. A recess 26 (see Figure 2) is provided in the outer surface of the cylindrical portion 24, the recess 26 extending axially of the shaft and being adapted to receive a key (not shown) which projects radially from the recess 26. An end portion 28 of the shaft extends outwardly from one end of the centre portion 26, having a length of at least about 11.43 cms (4.50 inches) but preferably not greater than 16.07 cms (6.33 inches). It is preferred that this end portion has a diameter of between about 11.099 cms (4.370 inches) and about 11.112 cms (4.375 inches). There is a substantially flat face 29 formed along at least part of the end portion 28, the face 29 being dimensioned to be engaged by the flat face 18 of a wedge element 16 of a wedge assembly 15 as described above. The length of the flat face 29 is preferably between about 11.17 cms (4.40 inches) and about 11.68 cms (4.60 inches). Provided on the end portion 28 are two recesses 30,31 which are axially aligned. The recess 30 is located closest to the central portion 24 of the shaft 2 and comprises a threaded bore (see Figure 8). The second recess 31 is of oval form, the axis of the oval being aligned with the axis of the shaft, the wall 32 defining the end of the recess 31 remote from the central portion 24 of the shaft being inclined (see Figure 8). Projecting axially from the end portion 28 is an extension portion 33 of a less diameter than the diameter of the end portion 28. The extension portion 33 has, adjacent its free end, a flat face portion 34. An axially extending threaded bore 35 is provided in the end face 36 of the extension portion 33. The male connection member 3 has an end 37 adapted to be connected to a railway car. A projecting portion 38 of the male connection member 3 extends towards the female connection member 1, the projection 38 defining a part spherical cavity, open on both sides of the projection, the cavity containing a ball 39 which is mounted for limited rotation. The ball 39 is provided with a diametrically extending, slightly tapering bore 40 dimensioned to receive the central portion 24 of the shaft 2. As can be seen most clearly from Figure 3, the ball 39 has a part spherical exterior 41 adapted to be received within the part spherical recess defined by the projection 38. As can be seen most clearly from Figure 4 the through-bore 40 of the ball 39 is provided with a radially outwardly extending key-way 42, the key-way being adapted to receive the key mounted in the recess 26 provided in the central portion 24 of the shaft 2. Effectively the key, which projects radially outwardly of the recess 26, provides a radial extension on the central portion 24, the extension being adapted to be received within the key-way 42 defined by the ball 39. Because the taper present on the central portion 24 corresponds with the taper of the bore 40, and because the key engaging the recess 26 engages the key-way 42, the shaft and the ball may be secured together. It is to be noted that the ball 39 defines a substantially flat face 43 which substantially surrounds each open end of the through-bore 40. Each face 43 is thus substantially annular, but is intersected by the key-way 42. Two clamping assemblies 44,44' are provided adapted to co-operate with the shaft 2 in order to retain the shaft 2 firmly in position relative to the ball 39. The clamping assemblies are identical, but of mirror-image configuration. The clamping assembly 44 will be described. The clamping assembly 44 comprises an elongate clamping element 45, a bolt 46 and two washers 47 which may comprise Belville washers. The clamping element 45 is of elongate form having a central portion 46 which defines a substantially centrally located oval aperture 47, the axis of the oval aperture being substantially parallel with the axis of the elongate portion 46. The upper surface 50 of the elongate portion 46 is substantially planar. The lower surface of the elongate portion 46, at one end, is arched or recessed 51 so that the under-surface of the element 45 may snugly engage the cylindrical exterior of the end portion 28 of the shaft 2. The right-hand end of the clamping element 45, as shown in Figures 5 and 6, is provided with an abutment face 52 which, as can be seen from Figure 7, is arcuate in elevation. The abutment face 52 is adapted to abut and engage part of the flat face 43 surrounding the end of the through-bore 40 provided in the ball 39. At the other end of the central elongate portion 46 of the clamping member 45 is a downwardly extending projection 53, the terminal face 54 of which is inclined inwardly in a tapering manner. The angle of inclination is the same as the angle of inclination of the wall 32 of the recess 31 in the shaft 2. The projection 53 is dimensioned to be inserted into the recess 31 formed in the end portion 28 of the shaft, with the inclined wall 54 of the projection 53 engaging the tapering wall 32 of the recess 31. The bolt 46 is adapted to pass through the washers 47, and through the oval bore 47 provided in the clamping element 45, the threaded end of the bolt 46 being adapted to be received within the threaded bore 30. It is to be appreciated that once the clamping element 45 has been mounted in position in this way, success of tightening of the bolt 46 will cause the projection 53 to become inserted more deeply in the recess 31, the inclined face 54 on the projection 53 thus sliding over the inclined side wall 32 of the recess 31, thus causing the clamping element to move towards the right into a clamping condition. When both clamping elements 45 of the two clamping assemblies 44,44' are in teh clamping condition, they firmly engage both sides of the ball 39, thus preventing axial movement of the shaft 2 relative to the ball 39. In assembling the coupling from the components described above, initially the projection 38 on the male member 3 is inserted into the recess 3, from the front. The shaft 2 is then moved horizontally, through the open side of the recess 4, and is moved into position until the tapering central portion 24 of the shaft 2 is snugly received within the bore 40 of the ball 39, with the key mounted in the recess 26 engaging the key-way 42. The clamping assemblies 44,44' are then placed in position and the bolts are tightened, so that the shaft 2 is fast with the ball 39. The end portions 28 of the shaft are then moved into the part cylindrical recess extensions 7 and the wedge assemblies 15 are located in position, with the bolts 21 passing through the Belville washers 22, and through the bore 19 present in the wedge member 16, passing through the spacer 23 and engaging the threaded bore 9 formed in the base 8 of the recess 5. The inclined front face 18 of the wedge element 16 engaging the flat face 29 provided on the end portion 28. The bolt 21 is then tightened, on each side of the assembly, so that each wedge 16 is firmly biassed against the flat face 29, urging the shaft firmly into the recess extension 7, so that the shaft is held in place in a slack-free manner. The flat faces 34 and the threaded bores 35 provided on the end portions 33 of the shaft facilitate rotation of the shaft and positioning of the shaft when the shaft is connected to the ball. The end portions of the shaft are accessible through the open sides of the recesses 4,4' of the female member 1. The ball may thus be appropriately positioned and the shaft may be appropriately positioned to facilitate the connection of the clamping assemblies 44,44' to the shaft and to facilitate the assembly of the wedging assemblies 15,15'. The horizontal shaft 2 is thus securely fixed to the female member, and cannot move in any direction. The cover 10 may then be located in position. The male member may move relative to the female member with a freedom of movement defined by the movement of the ball 39 within the recess defined by the projection 38 on the male coupling member 3. It is to be noted that the coupling, as described above, has a removable shaft member, since the shaft may readily be removed by reversing the procedural steps described above for assembling the coupling. A preferred embodiment of the invention is able to withstand a substantial force and provides a coupling in which there is no play, the coupling thus being substantially slack-free. While the invention has been described with reference to an embodiment in which a projection is provided on the central part of the shaft to provide a key-way in the ball, in an alternative embodiment to the invention the key-way in the ball may be provided with a projection adapted to be received within a key-way provided in the central part of the shaft.

Claims: An articulated coupling arrangement for connecting adjacent predetermined ends of a pair of railway cars in a substantially semi-permanent manner, the coupling comprising a female member (1) defining a recess (4), a male member (3) adapted to be inserted in the recess and carrying an articulated ball (39), and a removable shaft member (2) centrally engaged in the ball and having projecting end portions (28) received and retained within cooperating lateral recesses (5) provided in the female member (1), characterized in that the removable shaft member (2) comprises: a) a central portion (24), which has a slightly larger diameter at one of its ends than at the other so as to be slightly tapering, the ball (39) having a bore (40) with a corresponding diameter and taper for receiving the central portion; b) a key, which is disposed on the central portion (24) substantially parallel to the longitudinal axis of the shaft member (2) and cooperates with a key-way (42) in the ball (39) for preventing rotation of the latter relative to the shaft member; c) end portions (28) each with a diameter substantially equal to the diameter of an arcuate portion (7) in the side wall at the recess (4); d) a substantially flat face (29) formed along at least a part of each end portion (28) and being engageable by a substantially flat face (18) of a wedge element (16) thereby enabling securement of the male member (3) to the female member (1); and e) a clamping element (45), which is mounted on each end portion (28) and engages the side of the ball (39) to prevent axial movement of the shaft member (2) relative to the ball. A coupling arrangement according to claim 1, characterized in that each clamping element (45) has en abutment face (52) adapted to engage the ball (39) and has a downwardly extending projection (53), which has an inclined face (54) and is to be inserted in a recess (31) in the shaft end portion (18) defining a correspondingly inclined wall (32), means (46) being provided to urge the clamping element (45) into a clamping position with the inclined face (54) on the clamping element abutting the inclined wall (32) in the recess (31).

Inventors: DAUGHERTY DAVID W, HAWRYSZKOW MICHAEL GREGORY, KANJO WAJIH, DAUGHERTY, DAVID W., HAWRYSZKOW, MICHAEL GREGORY, KANJO, WAJIH
Applicants: WESTINGHOUSE AIR BRAKE CO, WESTINGHOUSE AIR BRAKE COMPANY
Application year: 1993
Main classification: B61G5
IPC codes: F16C3, B61G5