Patent Application
20140318412
Most conventional freight railroad cars include a car body and two spaced apart trucks. The car body or car body underframe includes two spaced apart center plates which respectively rest on and are rotatably or swivelly received by bolster bowls of the two trucks. The trucks rollingly support the car body along railroad tracks. Each truck includes two side frames and a bolster which supports the bolster bowl of that truck and which extends laterally between and is supported by the two spaced apart side frames. Each side frame defines a center opening and pedestal jaw openings on each side of the center opening. Each end of each bolster is supported by a spring group positioned in the center opening of the side frame and supported by the lower portion of the side frame which defines the center opening. Each truck also includes two axles which support the side frames, and four wheels and four roller bearing assemblies respectively mounted on the ends of the axles. The truck further includes four bearing adapters respectively positioned on each roller bearing assembly in the respective pedestal jaw opening and four bearing adapter pads respectively positioned on each bearing adapter. Each bearing adapter pad: (a) reduces the wear of the bearing adapter and the pedestal roof (i.e., the wall of the side frame which defines the top of the pedestal jaw opening) by reducing metal to metal contact between these components; and (b) decouples the axle and the wheels from the side frame to improve steering of the truck.
U.S. Pat. No. 7,387,074 discloses a bearing adapter and bearing adapter pad. The bearing adapter is configured to fit on top of the bearing assembly and the bearing adapter pad is configured to fit on top of the bearing adapter. The bearing adapter pad includes a body and four legs which respectively extend downwardly from opposite longitudinal edges of the body. The legs are spaced laterally at each longitudinal edge of the body such that the legs are received in openings between the laterally spaced shoulders of the bearing adapter. This bearing adapter pad is made from an elastomer such as polyurethane and is being commercially sold by Amsted Rail.
One problem with this elastomer bearing adapter pad is that it is non-conductive and thus is unable to provide electrical continuity or conductivity between the side frame and the bearing adapter (and thus between the car body and the tracks). Such electrical continuity or conductivity is needed to provide a ground for the car body which eliminates or reduces the buildup of static electricity on the car body. Such electrical continuity or conductivity is also needed to provide the ability for the car body or components thereof (such as electric solenoids for doors on bottom dump freight railroad cars) to obtain electrical power or electrical signals from the railroad tracks or rails. In other words, this electric continuity or conductivity is needed to provide electric power or electric signals transmitted from the tracks to one or more components of the car body. Such electrical continuity or conductivity is further needed to provide electrical continuity or conductivity between railroad cars to trigger railroad crossing signals.
Accordingly, Amsted Rail has manufactured this elastomer bearing adapter pad with copper plugs which extend through the body of the bearing adapter pad and which provide metal to metal conductive contact and thus electrical conductivity or electrical continuity between the pedestal roof and the bearing adapter. However, over time, these copper plugs tend to break off or wear down or off and then become less effective and possibly not effective at all in providing electrical continuity or conductivity between the side frame and the bearing adapter (and thus between the car body and the tracks).
Accordingly, there is a need to solve this problem.
The present disclosure provides a railroad car bearing adapter pad which solves the above problem. The railroad car bearing adapter pad of various embodiments of the present disclosure generally includes a body having one or more compressible resilient wear resistant conductive plugs which provide electrical conductivity and continuity between the side frame and the bearing adapter (and thus between the car body and the tracks). The bearing adapter pad of the present disclosure overcomes the above problem by providing a railroad car bearing adapter pad which ensures better electrical conductivity and continuity than known bearing adapter pads.
More specifically, the bearing adapter pad of various embodiments of the present disclosure includes one or a plurality of spaced apart compressible resilient wear resistant conductive plugs positioned in the top section of the body of the bearing adapter pad. Each of the conductive plugs transversely extends slightly above and slightly below the planes of the top and bottom surfaces, respectively, of the top section of the body of the bearing adapter pad to facilitate the electric conductivity or continuity between the side frame and the bearing adapter (and thus between the car body and the tracks through the center plate, the bolster bowl, the bolster bowl liner, the bolster, the side frame, the bearing adapter pad, the bearing adapter, the bearing assembly, the axle, and the wheel). In various embodiments, the conductive plugs are each made from a resilient material which enables them to continue to provide electric conductivity and continuity even when they are compressed or deformed. In various embodiments, the conductive plugs are also wear resistant.
Other objects, features, and advantages of the present disclosure will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts.
Referring now to the drawings and particularly to
More specifically, in this example illustration, the side frame 18 includes two downwardly extending pedestal jaws including a first pedestal jaw 22 and a second pedestal jaw (not shown) on the opposite side of the center opening 24 of the side frame 18. The pedestal jaw 22 includes an inside wall 26, a top wall or pedestal roof 28, and an outside wall 30 which generally define the pedestal jaw opening 33. The pedestal jaw 22 also includes an inner thrust lug 30 (not shown in
In this example illustration, the bearing adapter 50 generally includes a body 52, a plurality of legs 54, 56, 58, and 60 (not shown) extending downwardly from the body 52, and a plurality of raised edge supports 64, 66, 68, and 70 extending upwardly from the body 52. The body 52 of the bearing adapter 50 includes a substantially rectangular top section 72 which has a substantially flat top surface. The top section 72 and the raised edge supports 64, 66, 68, and 70 form a receiving surface and pocket for bearing adapter pad 100. The body 52 and the legs 54, 56, 58, and 60 (not shown) of the bearing adapter 50 include lower walls that define an arcuate opening 82 configured to receive or sit on the bearing assembly (not shown). In this example illustration, the bearing adapter 50 is a unitary cast steel structure, although it can be formed in other manners. It should be appreciated that the bearing adapter pad of the present disclosure can be implemented with differently configured bearing adapters.
In this illustrated embodiment, the bearing adapter pad 100 (as best seen in
As further illustrated in
Since each conductive plug 130, 132, 134, and 136 is identical in this illustrated example, conductive plug 130 is used as an example to further describe the conductive plugs. In this example embodiment, conductive plug 130 generally includes a central portion 140 and top and bottom engagers 142 and 144 which transversely extend from opposing sides of the central portion 140, and which are configured to engage the top wall 28 of the side frame 18 that defines the pedestal jaw opening 32 and the top surface of the top section 72 of the body 52 of the bearing adapter 50. More specifically, the plug 130 has a thickness (i.e., height) which is greater than the thickness (i.e., height) of the top section 112 of the bearing adapter pad 100. When the conductive plug is positioned centrally in and attached to the top section 112 as best shown in
In this illustrated embodiment, the conductive plug 130 and specifically the central portion 140 include an outwardly extending mounting flange or lip 148. The mounting flange 148 facilitates the attachment, forming coupling, or mating of the conductive plug to the top section 112 of the body 102 of the bearing adapter pad 100. In an alternative embodiment, the structure could be reversed such that the conductive plug includes one or more attachment slots or mounting slots sized to receive a mounting flange formed or extending from the central portion of the body of the bearing adapter pad into the mounting slot(s). The mounting flange 148 facilitates a secure and fixed mechanical engagement between the conductive plug 130 and the top section 112 of the body 102 of the bearing adapter pad 100. The present disclosure contemplates that the conductive plug may have more than one flanges or lips and that other suitable mechanical connections may be employed to better engage the top section of the body of the bearing adapter pad.
In this illustrated embodiment, the central portion of the conductive plug also defines an inner aperture 150 which extends transversely through the central portion. This aperture 150 is sized to receive a pin or support in the mold which maintains the relative position of the conductive plugs during the molding of the load-bearing portion and the rest of the bearing adapter pad 50 around the conductive plugs. The aperture also facilitates spring action of the conductive plugs. Specifically, if the conductive plug is compressed or deformed, the material of the plug will tend to move or stretch into the space of the aperture. This, in part, allows for the spring-like action of the conductive plugs.
In various embodiments of the present disclosure, the conductive plugs of the bearing adapter pad of the present disclosure are made from a urethane to resist cold flow and to be sufficiently compressible or resilient. In various embodiments of the present disclosure, the conductive plugs include conductive particles such as carbon black particles which make these plugs conductive. In various embodiments of the present disclosure, the urethane conductive plugs are unfilled except with the conductive particles because urethane has a greater memory characteristic which provides sufficient resiliency to the plugs and enables them to function in a spring-like manner. This is substantially different than the previous known copper plugs which tend to break or crush because they have no relative resiliency. In various embodiments of the present disclosure, the conductive plugs are injection molded. It should be appreciated that the conductive plugs could alternatively be partially filled with strengthening material such as glass particles or strands to add a desired amount of strength to the plugs; however, such additional strength would reduce the memory effect of the compressible resilient conductive plugs.
In various embodiments of the present disclosure, the conductive plugs are made from a urethane filled with approximately 20% to 25% of carbon black particles. This material is commercially available from numerous sources such as RTP, Advance Polymer Compounding (APC), Noveon, Bayer, GE Plastics, and Dow Chemical. It should be appreciated that the conductive plugs can be made from a carbon black filled urethane in the range of approximately 10% to 50%, and that other ranges are possible. The plugs with the carbon black conductive particles serve to assure electrical conductivity between the upper and lower surfaces of the conductive plug to electrically connect the side frame with the bearing adapter which in turn provides the car body with a grounding mechanism to avoid the build-up of static electricity in the car body and to provide the ability to receive signals from the railroad tracks.
In one embodiment, the top section and legs of the bearing adapter pad 100 are formed from a cast or injection molded polymer or elastomer such as a cast elastomer of a durometer hardness between 90A and 58D. In one embodiment, the top section and legs of the bearing adapter pad of the present disclosure are made by injection molding or otherwise suitably forming the conductive plugs and then injection molding the top section and legs around and between the conductive plugs. More specifically, the conductive plugs can be injection molded cylindrical plugs placed in an injection mold in a spaced-apart symmetrical relation and the top section is injection molded around the conductive plugs under suitable pressure and heat to form the bearing adapter pad as a monolithic structure. The top section and the conductive plugs are thus fused together to form a one-piece bearing adapter pad. The flange or lip or other mounting member also provides a mechanical lock, engagement or coupling between the conductive plugs and the top section of the bearing adapter pad.
In another embodiment, the top section and legs of the bearing adapter pad are formed from a cast or injection molded polymer or elastomer and the plugs are press fit into the top section of the bearing adapter pad. In one such embodiment, the plugs do not include the mounting flanges, the top section is formed without the plugs, holes are drilled or punched in the top section, and the plugs are press fit into the holes.
It should be appreciated that the present disclosure relates to: (a) the bearing adapter pad by itself; (b) the bearing adapter pad in combination with a bearing adapter; (c) the bearing adapter pad in combination with a bearing adapter and a side frame; (d) the bearing adapter pad in combination with a side frame; (d) the bearing adapter pad in combination with a bearing adapter and a side frame; (e) a railroad car truck including the bearing adapter pad among the other components; and (f) a railroad car including the bearing adapter pad among the other components.
It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, and it is understood that this application is to be limited only by the scope of the claims.
