FIELD OF THE INVENTION

The present invention relates generally to a bearing and is more particularly directed to a bearing for a rail car coupling, the bearing has arcuate bearing surfaces and an anchor member for restraining axial movement.

BACKGROUND OF THE INVENTION

A train of rail cars typically includes multiple rail cars coupled to one another via a rail car coupling. Rail car couplings generally include a bearing that connects a first coupling linkage attached to the rear of a leading rail car to a second coupling linkage attached to the front of a trailing rail car. The bearing includes an inner member moveably positioned in an outer member. The inner member may be secured to either of the first coupling linkage or the second coupling linkage. The outer member may be secured to the other of the first coupling linkage or the second coupling linkage.

Prior art bearings have been unable to adapt to various track and rail conditions. For example, prior art bearings have been unable to adequately operate as the train of rail cars travels around a left or right hand turn, when the train of rail cars travels up or down a slope, and when the train travels on a banked track. In addition, the bearing transmits loads between the inner member and the outer member in response to pulling or pushing of adjacent rail cars which can create vertically upward force components that can cause the inner member to dislodge from the outer member.

SUMMARY

According to aspects illustrated herein there is disclosed a bearing that includes an outer member having a base portion and a first concave surface. The base portion has a first convex surface extending from a second axial end thereof. The base portion and the first concave surface cooperate to define a cavity in the outer member. The base portion has a first aperture extending therethrough. The bearing includes an inner member having a second convex surface and is positioned partially in the cavity such that the second convex surface slidingly engages the first concave surface. The inner member has a second aperture extending therethrough. The bearing includes an anchor member defined by a shaft and a head extending radially outward from the shaft. A portion of the shaft extends through the first aperture and is removably secured in the second aperture. The head has a second concave surface that slidingly engages the first convex surface.

The anchor member has operational and safety utility in catastrophic failure situations in which portions (e.g., peripheral components) of the bearing fail, the inner member and the outer member will not separate. During operation, the anchor member holds the bearing together in response to a vertically upward component of loads transmitted through the bearing.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side cross sectional view of a bearing of the present invention;

FIG. 2 is a side cross sectional view of the bearing of FIG. 1 having a self-lubricating liner disposed therein;

FIG. 3 is a side cross sectional view of the bearing of FIG. 1 shown with the inner member tilted relative to a central axis and shown without a sealing member;

FIG. 4 is a side cross sectional view of the bearing of FIG. 1 installed in a rail car coupling; and

FIG. 5 is a top view of the bearing of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1 , a spherical bearing for a rail car coupling is generally designated by the numeral 10. As illustrated in FIG. 4, the bearing 10 is disposed in a rail car coupling assembly 100. As shown in FIG. 4, the bearing 10 is clamped between a first coupling member 80 and a second coupling member 81. The first coupling member 80 is secured to a portion of a leading rail car 300 by fasteners 301. The second coupling member 81 is secured to a portion of a trailing rail car 200 by fasteners 201. The bearing 10, first coupling member 80 and the second coupling member 81 cooperate to pivotally couple the leading rail car 300 and the trailing rail car 200 to one another in a train of rail cars.

As described further herein, the bearing 10 is configured to carry loads and allow misalignment in multiple directions as the train of rail cars travels along a track (not shown) in the directions indicated by the arrow T. The track includes two rails (not shown) spaced equally apart from one another. The two rails each have a load bearing surface that is spaced apart from a foundation by a predetermined height. In one embodiment, the two rails include portions which are spaced apart from the foundation by different heights such as occurs with banked tracks. The rails are laid out in a path that includes left and right hand curves and inclined slopes. The bearing 10 is configured to misalign as the train of rail cars travels through the left and right hand curves, inclined slopes, sections of the track having rails with different heights and combinations thereof.

The bearing 10 has an outer member 12 having a base portion 14 and a first concave surface 16 extending outwardly and upwardly from a first axial end 18 of the base portion 14. The base portion 14 has a first convex surface 20 extending inwardly and downwardly from a second axial end 22 of the base portion 14. The base portion 14 and the first concave surface 16 cooperate to define a cavity 24 in the outer member 12. The base portion 14 has a first aperture 26 extending therethrough. The bearing 10 includes an inner member 28 having a second convex surface 30. The inner member 28 and the outer member 12 are concentric with a central axis A. The inner member 28 is rotatably mounted with respect to the outer member 12 so that the inner member 28 and the outer member 12 are rotatably relative to one another. A portion of the inner member 28 is positioned in the cavity 24 such that the second convex surface 30 slidingly engages the first concave surface 16.

The inner member 28 has a second aperture 27 extending therethrough. The bearing

10 includes an anchor member 34 defined by a shaft 36 and a head 38 extending radially outward (from the central axis A in the direction indicated by the arrows Q) from a first end 36 A of the shaft. A second end 36B of the shaft 36 extends through the first aperture 26 and is removably secured in the second aperture 27, for example by a threaded connection 27T. The head 38 has a second concave surface 40 facing the second end 36B of the shaft 36. The bearing 10 supports downward and reverse pullout loads along the central axis A and tilted axis A' as shown in FIG. 3. In particular, the second concave surface 40 slidingly engages the first convex surface 20 to restrain axial movement of the inner member 28 relative to the outer member 12 along the central vertical axis A or the tilted axis A'. During operation, the anchor member 34 holds the bearing 10 together in response to a vertically upward component of loads transmitted through the bearing 10 (e.g., between the inner member 28 and the outer member 12).

As shown in FIG. 1, the base portion 14 defines an axial facing first abutment surface 42 extending between the first concave surface 16 and the first aperture 26. The inner member 28 defines second abutment surface 28A extending between the second convex surface 30 and the second aperture 27. The first abutment surface 42 and the second abutment surface 28A engage one another when an angular range (e.g., angle H, as shown in FIG. 3) of misalignment (indicated by the arrows G) of the inner member 28 relative to the outer member 12 is at a maximum. As shown in FIG. 3, the angle H depicts a misalignment of the inner member 28 relative to the outer member 12 so that the inner member 28 tilts relative to the vertical axis A, as indicated by the tilted axis A'. In one embodiment, the misalignment indicated by the arrows G is oriented in a plane that is coincident with a direction of travel T of the train of rail cars. Such misalignment in the form of axial tilting of the inner member 28 relative to the outer member 12 occurs, for example, as the train of rail cars travels up or down an inclined slope. When the train of rail cars travels up or down the inclined slope, the bearing 10 allows a front to back misalignment of the first coupling linkage with respect to the second coupling linkage by allowing the inner member to pivot or tilt relative to the outer member in the plane coincident with the direction of travel T.

The bearing 10 is also configured to traversely misalign in one or more planes traverse to the plane that is coincident with the direction of travel T, for example

perpendicular to the direction of travel. Such traverse misalignment of the inner member 28 relative to the outer member 12 occurs, for example, as the train of rail cars travels over banked portions of the track where each of the rails has a different height.

In addition, the bearing 10 is configured for rotational misalignment of the outer member 12 relative to the inner member 28 in the direction indicated by the arrow V, as illustrated in FIG. 5. Such rotational misalignment occurs, for example, when the train of rail cars travels through a left or right hand curve.

The bearing 10 is configured to accommodate the misalignment indicated by the arrows G that is oriented in the plane that is coincident with the direction of travel T of the train of rail cars, the traverse misalignment and the rotational misalignment, concurrently.

In one embodiment, the maximum magnitude of the angle H is 7 degrees in any direction from the central axis A (as shown in FIG. 3) to the tilted axis A'. The first convex surface 20, the first concave surface 16, the second convex surface 30 and the second concave surface 40 have a common radius of curvature R originating from a common point P of rotation, as shown in FIG. 1. While the angle H is described as being 7 degrees, the present invention is not limited in this regard as any angle may be employed including but not limited to less than 7 degrees (e.g., 4, 5, 6 or less degrees) or greater than 7 degrees (e.g., 8, 9, 10, 11, 12 or more degrees).

As illustrated in FIG.1 , the second abutment surface 28A tapers axially away from a flat bottom portion 28B at an angle K to provide a full line of engagement along the second abutment surface 28A and the first abutment surface 42, when the angular range of misalignment is at the maximum as illustrated in FIG. 3. In addition, the taper of the abutment surface 28A allows for a greater angular range of misalignment than an inner member with an entirely flat bottom. In one embodiment, the angle K is about equal to the angle H.

Referring to FIGS. 1 and 3, the head 38 has a peripheral edge 38E, shown, for example, as a tapered circumference around the head 38. A cover 44 is removably positioned on the outer member 12 proximate the second axial end 22 of the base portion 14, for example, by threadable engagement. The head 38 is positioned between the cover 44 and the first convex surface 20. The outer member 12 has a third abutment surface 44D defined by a radially inward facing portion of the cover 44. The peripheral edge 38E engages the third abutment surface 44D when an angular range of misalignment of the inner member 28 relative to the outer member 12 is at a maximum. The peripheral edge 38E is tapered at an angle Kl relative to the central axis A to provide a full line of engagement along the third abutment surface 44D and the peripheral edge 38E, when the angular range of misalignment is at the maximum as illustrated in FIG. 3. In addition, the taper angle Kl of the peripheral edge 38A allows for a greater angular range of misalignment of the head 38 than a head with a peripheral edge without a taper. In one embodiment, the angle Kl is about equal to the angle H. In one embodiment, the head 38 has a third convex outer surface 60 configured to maintain a clearance G4 between the third convex surface 60 and an inward facing surface 44F of the cover 44 when the anchor member 34 moves from a central position to a maximum angular displacement, as shown in FIG. 3.

As illustrated in FIG. 1, the shaft 36 is adjustably secured in the first aperture 27 at a predetermined torque to create a predetermined friction force between the anchor member 34 and the outer member 12 and between the inner member 28 and the outer member 12 . For example, the shaft 36 is threaded into a female threaded portion 27T of the first aperture 27. In one embodiment, the first aperture 27 has a female threaded bore 27 of a diameter D2 and transitions at a shoulder 27B, to a smaller threaded bore 27 A having a diameter Dl. In one embodiment, the second end 36B of the shaft 36 abuts the shoulder 27B. In one embodiment, a locking device, for example a set screw 56 is removably threaded into the smaller threaded bore 27 A and is torqued and seated against the second end 36B of the shaft 36, for locking the anchor member 34 in a predetermined position.

As shown in FIGS. 1 and 3, the inner member 28 has a groove 48 formed

circumferentially around the inner member between a radially outer surface 28R and the first convex surface 30. A retaining clip 50 is disposed in the groove 48. Another groove 52 is formed in a radially outer surface 12R of the outer member 12. An annular seal 55 has one end positioned in the retaining clip 50 and another end thereof positioned in the groove 52. The seal 55 is an accordion type and made from an elastomeric material that stretches and contracts in response to movement of the inner member 28 relative to the outer member 12.

Referring to FIG. 2, a first lubricious liner 70 is disposed between the first concave surface 16 of the outer member 12 and the second convex surface 30 of the inner member 28. In one embodiment, a second lubricious liner 72 is disposed between the first convex surface 20 of the base portion 14 and the second concave portion 40 of the head 38 of the anchor member 34. In one embodiment, the first and second lubricious liners 70 and 72 are manufactured from self-lubricated materials and liners, such as but not limited to

polytetrafluoroethylene (PTFE) materials (e.g., Uniflon-E manufactured by Uniflon

Fluoromasters of Brazil) and liner systems with resins including, phenolic resins, polymid resins and polymid resins in conjunction with fiber weaves, fabrics or matrix materials, including but not limited to polyester, meta-aramids (e.g., NOMEX), PTFE and glass. In one embodiment, the self-lubricated material and liners are a homogeneous entity or are a molded nearly homogenous system without a weave, fabric or matrix and are manufactured from one or more acrylates.

In one embodiment, the first lubricious liner 70 is secured to the first concave surface 16. In one embodiment, the first lubricious liner 70 is secured to the second convex surface 30. In one embodiment, the first lubricious liner 70 is floating between the second convex surface 30 and the first concave surface 16.

In one embodiment, the second lubricious liner 72 is secured to the first convex surface 20. In one embodiment, the second lubricious liner 70 is secured to the second concave portion 40. In one embodiment, the second lubricious liner 70 is floating between the s second concave portion 40 and the first convex surface 20.

While the first and second lubricious liners 70 and 72 have been shown and described, the present invention is not limited in this regard as in one embodiment the first and second lubricious liners 70, 72 are not used and instead a lubricant such as grease may be disposed between the first concave surface 16 of the outer member 12 and the second convex surface 30 of the inner member 28; and/or between the first convex surface 20 of the base portion 14 and the second concave portion 40 of the head 38 of the anchor member 34.

Referring to FIGS. 1-3, the inner member 28 has a plurality (only two shown in the cross sectional view of FIGS. 1-3 and four shown in FIG. 5) of threaded bores 75 extending into an axially outward facing surface 28X of the inner member 28 for receiving threaded fasteners (75F shown in FIG. 4) therein for securing the inner member 28 to a portion of a rail car coupling as described herein with reference to FIG. 4. The outer member 12 has a plurality (only two shown in the cross sectional view) of threaded bores 76 extending into an axially outward facing surface 12X of the outer member 12 for receiving threaded fasteners (76F shown in FIG. 4) therein for securing the inner member to a portion of a rail car coupling, as described herein with reference to FIG. 4.

As illustrated in FIG. 4, the bearing 10 is disposed in a rail car coupling assembly 100. The bearing 10 is clamped between a first coupling member 80 and a second coupling member 81. The first coupling member 80 is secured to the axially outward facing surface 28X of the inner member 28 with suitable fasteners 75F threaded into the threaded bores 75. A mounting cap 82 is used as centering device during assembly of the rail car coupling assembly 100. The mounting cap 82 is temporally secured to the axially outward facing surface 28X of the inner member 28 with a suitable fastener threaded into the smaller threaded bore 27 A and later removed after assembly. The second coupling member 81 is secured to the axially outward facing surface 12X of the outer member 12 with suitable fasteners 76F threaded into the treaded bores 76.

While the present disclosure has been described with reference to various exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.