The present disclosure is related to railway car couplers, and more particularly to a railway car coupler and knuckle system and method.
Railcar couplers are disposed at each end of a railway car to enable joining one end of such railway car to an adjacently disposed end of another railway car. The engageable portions of each of these couplers is known in the railway art as a knuckle. For example, railway freight car coupler knuckles are taught in U.S. Pat. Nos. 4,024,958; 4,206,849; 4,605,133; and 5,582,307.
In many cases when a railcar knuckle fails, a replacement knuckle must be carried from the locomotive at least some of the length of the train, which may be up to 25, 50 or even 100 railroad cars in length. The repair of a failed coupler can be labor intensive, can sometimes take place in very inclement weather and can cause train delays.
In accordance with a particular embodiment, a railway car coupler system includes a railcar coupler comprising a coupler head portion extending from a shank portion. The coupler head portion is configured to couple to a first coupler knuckle for coupling the railcar coupler to a second railcar coupler of an adjacent railcar. The coupler head portion comprises a coupler pivot pin hole for receiving a pivot pin for coupling the railcar coupler to the first coupler knuckle. The pivot pin hole has a longitudinal axis. The coupler head portion comprises top and bottom coupler pulling lugs each having a respective coupler pulling lug engagement face. At least one of the coupler pulling lug engagement faces of the top and bottom coupler pulling lugs is angled with respect to the longitudinal axis.
The at least one coupler pulling lug engagement face angled with respect to the longitudinal axis may be angled approximately 30 degrees from the longitudinal axis. The first coupler knuckle may comprise top and bottom knuckle pulling lugs for engaging with the top and bottom coupler pulling lugs, respectively. The top and bottom knuckle pulling lugs may each have a respective knuckle pulling lug engagement face. At least one of the knuckle pulling lug engagement faces of the top and bottom knuckle pulling lugs may be angled with respect to the longitudinal axis.
In accordance with another embodiment, a method includes casting a railcar coupler comprising a coupler head portion extending from a shank portion. The coupler head portion is configured to couple to a first coupler knuckle for coupling the railcar coupler to a second railcar coupler of an adjacent railcar. The coupler head portion comprises a coupler pivot pin hole for receiving a pivot pin for coupling the railcar coupler to the first coupler knuckle. The pivot pin hole has a longitudinal axis. The coupler head portion comprises top and bottom coupler pulling lugs each having a respective coupler pulling lug engagement face. At least one of the coupler pulling lug engagement faces of the top and bottom coupler pulling lugs is angled with respect to the longitudinal axis.
Technical advantages of particular embodiments include angled pulling lugs which facilitate distribution of load on both sets of pulling lugs even if only one makes contact during engagement. This is intended to prevent loading of only one set of pulling lugs in some circumstances. In addition, an increased distance between a pivot pin hole and pivot pin protector better ensures that the pivot pin is not loaded before the pulling lugs. Moreover, a mating geometry between a lock and a knuckle better ensures that the lock will move in place with the knuckle during coupler engagement.
Other technical advantages will be readily apparent to one of ordinary skill in the art from the following figures, descriptions, and claims. Moreover, while specific advantages have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages.
A more complete understanding of embodiments of the invention will be apparent from the detailed description taken in conjunction with the accompanying drawings in which:
Example embodiments and their advantages are best understood by referring to
Coupler head 10 may be configured to receive a knuckle. The knuckle may be received and retained in a pivotal manner with a pivot pin that extends through pivot pin holes 18 of pivot lugs 16. The pin may be protected by pin protectors 20 when it extends through pivot pin holes 18 and a corresponding pin hole in the knuckle. Located behind pivot lugs 16 are top buffing shoulder 22 and bottom buffing shoulder 24. Together, top and bottom buffing shoulders 22 and 24 form a pocket for receiving the knuckle. Buffing shoulders 22 and 24 may receive the transferred load from an interfacing surface of a knuckle when the railway car experiences buff (pushing) motions.
Extending from a lower portion of coupler head 10 adjacent bottom buffing shoulder 24 is bottom pulling lug 26. Extending from a top surface of coupler head 10 adjacent top buffing shoulder 22 is top pulling lug 28. At least a portion of top pulling lug 28 may be generally aligned with a portion of bottom pulling lug 26.
When a knuckle is assembled with coupler head 10, pulling lugs 26 and 28 may engage corresponding pulling lug surfaces of the knuckle. This engagement may allow pulling lugs 26 and 28 to receive a transfer draft load from a corresponding knuckle of a mating coupler on an adjacent railcar.
The knuckle (and its identical counterpart on an adjacent coupler) may operate by contacting the guard arm of an adjacent coupler. In a joining operation, the knuckle of coupler head 10 and the opposing knuckle may each pivot inward to a degree sufficient to lock the two knuckles in place behind each other so that coupler head 10 is properly joined with the adjacent coupler. A lock member slidably disposed within each coupler head 12 may be activated by the engagement to slide downward within the coupler head 10 and lock the knuckle in place to thereby join the two railway couplers together.
For example, if during railcar coupling only one set of pulling lugs makes contact (e.g., top coupler pulling lug 128 with top knuckle pulling lug 152 or bottom coupler pulling lug 126 with bottom knuckle pulling lug 154), then one pulling lug will ride up such that load is distributed on the other set of pulling lugs that did not originally make contact with each other. Thus, if the respective bottom pulling lugs are loaded first, their angled configuration will ensure that both sets of pulling lugs will load.
The engagement faces of top coupler pulling lug 128 and top knuckle pulling lug 152 may include gap distances 131 and 133 between them at initial assembly. In particular embodiments, the coupler and knuckle and their respective pulling lugs may be configured such that gap distances 131 and 133 are approximately 1/16″ or less. Such a small distance reduces the chance for shock loading as a result of the small distance of travel of the pulling lugs. Gap distances 131 and 133 may be different in particular embodiments. In particular embodiments, gap distance 131 may be approximately 0.0612″, and gap distance 133 may be approximately 0.0294″.
Couplers and knuckles of particular embodiments may be manufactured through a casting process with steel or other alloy. Typically one or more cores are used in the manufacturing process in order to form various cavities in the coupler and knuckle. The cores are typically made of resin or otherwise hardened sand. Specifically, the coupler and/or knuckle may each be produced in a mold cavity within a casting box between cope and drag sections. Sand, such as green sand, is used to define the interior boundary walls of the mold cavity. The mold cavity may be formed using a pattern and may include a gating system for allowing molten alloy to enter the mold cavity. The mold cavities define the exterior surfaces of the coupler and knuckle. The cores used to form cavities are placed at appropriate locations within the mold cavity. Once the coupler and/or knuckle is cast, the sand or resin cores may be removed leaving the cavities. The coupler and knuckle may each undergo a metal finishing process that includes finishing the surfaces of the coupler and knuckle.
In particular embodiments, slotted pivot pin hole 260 may be elongated as illustrated. Slotted pivot pin hole 260 may provide advantages when using a conventional coupler and a knuckle with angled pulling lugs of particular embodiments. For example, slotted pivot pin hole 260 may minimize additional load that might be placed on a pivot pin when angled pulling lugs of particular embodiments are used with a conventional coupler.
As described, technical advantages of particular embodiments include angled pulling lugs which faciliate distribution of load on both sets of pulling lugs even if only one makes contact during engagement. This prevents loading of only one set of pulling lugs in some circumstances. In addition, an increased distance between a slotted pivot pin hole and pivot pin protector better ensures that the pivot pin is not loaded before the pulling lugs. In particular embodiments, a mating geometry between a lock and a knuckle better ensures that the lock will move in place with the knuckle during coupler engagement.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
The present application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/793,859, filed Mar. 15, 2013 and incorporated by reference herein.
Filing Document | Filing Date | Country | Kind |
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PCT/US2014/026375 | 3/13/2014 | WO | 00 |
Number | Date | Country | |
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61793859 | Mar 2013 | US |