Patent Application
20220315069
Railway cars in a train are connected to an adjacent car by a coupler. The coupler is joined to a yoke and the assembly is mounted in a railway car center sill. In “cushioned” railway cars, to prevent damage to the railway cars and the laded goods during operation, and during assembly of the railway car train in the yard, various devices have been installed to absorb loads on the coupler so that impact forces transmitted to the railway car are reduced. These cushioning devices include draft gear, hydraulic (EOCC) units, and “selective cushioning units” as described below.
The coupler extends from the yoke at the end of the railway car and may be subject to “droop,” which occurs when the coupler head deflects downward due to gravity and normal usage. Excessive droop may cause alignment problems when couplers of adjacent cars are connected, as well as other misalignments of various pieces of equipment attached to the coupler.
In an “E-type” yoke, the coupler is attached to the yoke with a draft key, and vertical forces on the draft key may cause the key to crack and deform, which can cause costly repair.
The inventors herein have studied the problems posed by vertical forces on the coupler in a variety of yoke-coupler environments and configurations to develop solutions to these problems, including problems posed by coupler droop.
Thus, an object of the invention is to configure E-Type yokes in a variety of environments to prevent coupler droop. Another object is to provide methods for modifying a yoke to prevent coupler droop.
In one aspect, the invention is a yoke for a railway car, comprising: an open front end adapted to receive a coupler shank, a vertical tail wall opposite the front end, a top wall and a bottom wall opposite the top wall, a first side wall connecting the top wall and the bottom wall, and a second side wall opposite the first side wall, the first and second side walls each having an aligned key slot toward the front end of the yoke adapted to receive a coupler key laterally, the top and bottom wall each having an interior surface adapted to face the coupler shank and defining an interior space in the yoke; and a coupler support extending from the top wall into the interior space of the yoke adapted to contact the coupler shank and prevent downward deflection of the coupler.
In the context of an end of car cushioning (EOCC) unit wherein an E-type yoke engages a hydraulic unit, the coupler support feature of the present invention may provide support from the top wall of the yoke in addition to a support feature on the bottom wall of the yoke supporting the coupler shank from below.
In this aspect, an end-of-car cushioning apparatus according to the invention comprises the yoke as described above, a coupler shank received in the front end of the yoke abutting the vertical rear (or “tail”) wall of the yoke, a coupler support extending from the top wall into the interior space of the yoke adapted to contact the coupler shank and reduce downward deflection of the coupler, and a hydraulic unit positioned behind the vertical rear wall of the yoke, comprising a piston received in a recess of the yoke behind the vertical rear wall of the yoke and a cylinder filled with a fluid and receiving the piston, wherein the fluid is adapted to dissipate forces when the piston moves in the cylinder in response to loads on the coupler.
In other embodiments, a yoke equipped with a coupler support may be configured to accommodate “selective cushioning apparatuses” such as disclosed in U.S. Pat. Nos. 10,308,283, 10,513,275, and in U.S. pending application Ser. No. 16/206,097, filed Nov. 30, 2018, and No. U.S. Ser. No. 16/250,267, filed Jan. 17, 2019, all of which are by the inventors herein and are incorporated herein by reference in their entirety. In some of these apparatuses, a stack of elastomeric units may be positioned inside a specially configured yoke, cushioning buff and draft loads on the coupler, and a stack of elastomeric units may be positioned in the sill behind the yoke to cushion buff loads on the coupler. In combination, these systems may yield cushioning performance as good or better than a hydraulic cushioning unit, without the drawbacks of a hydraulic cylinder.
For example, an end-of-car cushioning apparatus for a railway car according to the invention may comprise: an E-Type yoke adapted to receive a coupler shank, substantially as described above, a coupler follower received in the yoke behind the coupler shank adapted to move inside the yoke in response to draft and buff loads on the coupler, and a first stack of elastomeric units positioned between the coupler follower and the vertical rear wall of the yoke compressed in response to buff and draft loads on the coupler. The yoke is provided with a coupler support protruding from the interior surface of the top wall in front of the coupler follower contacting the coupler shank when the end of the coupler extending from the railway car is subjected to downward forces. In embodiments, the center of gravity of the yoke and coupler combination is positioned inboard of the end of the car, which reduces vertical forces on the draft key.
Coupler support may also be provided on a standard E-Type draft gear configuration. In this aspect, a yoke is provided having an open front end adapted to receive a coupler shank, a vertical tail wall opposite the front end, a top wall and a bottom wall opposite the top wall, a first side wall connecting the top wall and bottom wall, and a second side wall opposite the first side wall. The first and second side walls each have an aligned key slot toward the front end of the yoke adapted to receive a coupler key laterally, and the top and bottom walls each have an interior surface adapted to face the coupler shank defining an interior space in the yoke. A coupler shank is received in the front end of the yoke abutting a coupler follower which is positioned inside the yoke and adapted to move in response to forces on the coupler. A coupler support is provided extending from the top wall into the interior space of the yoke adapted to contact the coupler shank and reduce downward deflection of the front end of the coupler. A frictional draft gear comprising a housing, an elastic element received in the housing, and a piston or friction clutch compressing the elastic element in response to buff and draft loads on the coupler, is provided in the interior space of the yoke.
In embodiments, the apparatus is configured for installation in an EOC-7 or EOC-8 sill pocket and is provided with a coupler support protruding into an interior space of the yoke and engaging the shank to prevent the coupler head from deflecting downward.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
The drawings may not be to scale and features not necessary for an understanding of the invention are not shown.
Directions and orientations herein refer to the normal orientation of a railway car in use. Thus, unless the context clearly requires otherwise, the “front” of a coupler is in a direction away from the body of the car and “rear” is in a direction from the front end of the coupler toward the car body. Likewise, the “longitudinal” axis or direction is parallel to the rails and in the direction of movement of the railway car on the track in either direction. The “transverse” or “lateral” axis or direction is in a horizontal plane perpendicular to the longitudinal axis. The term “inboard” means toward the center of the car, and may mean inboard in a longitudinal direction, a lateral direction, or both. Similarly, “outboard” means away from the center of the car. “Vertical” is the up-and-down direction and the “vertical plane” is perpendicular to the longitudinal axis. “Horizontal” is a plane parallel to the surface the train travels on. “Up” and “upward” mean toward the sky and “down” and “downward” mean toward the ground.
As used herein, the term “about” associated with a numerical value is understood to indicate a margin of +/−20% of the value. In embodiments, “about” indicates a range of +/−10% of the stated numerical value. In still other embodiments, “about” indicates a range of +/−5% around the stated numerical value. When used to modify a range of values, “about” indicates +/−20%, +/−10% or +/−5% of the range.
“Droop” is downward deflection of the coupler head with respect to a horizontal orientation.
“Elastomer” and “elastomeric” refer to polymeric materials having elastic properties so that they exert a restoring force when compressed. Examples of such materials include, without limitation, thermoplastic elastomer (TPE), natural and synthetic rubbers such as: neoprene, isoprene, butadiene, styrene-butadiene rubber (SBR), polyurethanes, and derivatives. Thermoplastic copolyesters used in some conventional draft gear may be used in the stacks of elastomeric units according to the invention.
“Travel” refers to a distance traveled by the coupler when the cushioning elements are fully compressed. “Travel” generally refers to the full possible extent of such movement, e.g., when the elastomeric pads in a stack of elastomeric units are compressed and the metal plates of adjacent elastomeric units contact one another. Travel may be draft travel or buff travel, permitted by the draft gear, by the one or more stacks of elastomeric units or by a hydraulic unit, as the case may be.
A person having ordinary skill in the art has a general knowledge of standards and procedures established by the Association of American Railroads (“AAR”) and the published AAR standards cited herein are incorporated by reference as background. Reference herein to AAR standards refers to standards in effect on the filing date of this application. In non-limiting embodiments, the selective cushioning apparatus fits between front and rear stops of an “EOC-7” pocket of about 38¾ inches described in AAR standard S-181. In other embodiments, the cushioning unit fits between front and rear stops of an “EOC-8” pocket, having a pocket length of about 48¾ inches described in AAR standard S-181. In other embodiments, the cushioning device may be adapted to fit other AAR standard or non-standard pocket dimensions depending on the application.
As used herein the term “E-Type” refers to a yoke connected to a coupler by a coupler key (also called a “draft key”) inserted laterally and does not necessarily refer to a standard-dimension yoke. A yoke utilized with a selective cushioning unit according to the invention will typically be longer than a standard E-Type yoke used with a hydraulic unit, but the configuration would be recognizable as “E-Type” to a person having ordinary skill in the art and would be interoperable with railway car components configured for use with a conventional E-Type yoke. In some embodiments, the selective cushioning apparatus fits into a standard sill pocket for a hydraulic unit.
A cushioning unit according to one embodiment of the invention is depicted in the perspective view of
In the cutaway detail view of
In the embodiment shown in
In embodiments, one or more stacks 14 of elastomeric units may be provided behind the yoke to absorb buff loads on the coupler. As in the aforesaid patents and co-pending applications by the inventors herein, these “buff” stack(s) of elastomeric units may comprise a set of rigid metal plates, each metal plate having at least one elastomeric pad thereon, adapted so that each metal plate of the elastomeric units contacts an adjacent metal plate at full compression of the stack. Preferably, full compression of first stack 17 and second stack 14 permits buff travel in a range of about 6 to 18 inches. In embodiments, where the apparatus is adapted to fit into an EOC 7 pocket, at full compression of the first stack and the second stack, the apparatus permits buff travel in a range of about 7 to about 8 inches. In another embodiment, where the apparatus is adapted to fit into an EOC-8 pocket, a longer second stack is provided, which provides buff travel in a range of about 9 to about 10 inches. Thus, in embodiments, the selective cushioning apparatus is retrofit for a pocket designed for an EOC-7 or EOC-8 end of car arrangement, replacing a draft gear or hydraulic unit.
A first or “draft” stack of elastomeric units 32 may be provided in area 120 in front of tail wall 11 of yoke 12 behind coupler follower 13. Each elastomeric unit 32 comprises a metal plate and at least one elastomeric pad, and at full travel, metal-to-metal contact is made between adjacent metal plates to control the amount of travel and prevent over-compression of the elastomeric pads. Lateral guide 33 may be provided to assist in the alignment of elastomeric units 32 in yoke 12. In the embodiment shown, coupler follower 13 is also provided with a notch to avoid lateral guide 33.
The description of the foregoing preferred embodiments is not to be considered as limiting the invention, which is defined according to the appended claims. The person of ordinary skill in the art, relying on the foregoing disclosure, may practice variants of the embodiments described without departing from the scope of the invention claimed. A feature or dependent claim limitation described in connection with one embodiment or independent claim may be adapted for use with another embodiment or independent claim, without departing from the scope of the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/027645 | 4/10/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16445364 | Jun 2019 | US |
| Child | 17619805 | US |
