1. Field of the Invention
The present invention relates to railroad couplers, and more particularly to an improved knuckle thrower having improved resistance to handling load forces.
2. Brief Description of the Related Art
Railroad vehicles are generally connected together with couplers. Railroad couplers are typically constructed to railroad standards so that couplers used on railroad cars may be coupled together, even if produced by different manufacturers. Common are American Association of Railroads (“AAR”) Standard E and F type railroad car couplers, and, in particular, the knuckles used in these couplers. 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 are known in the railway art as a knuckle.
The coupling assembly for a railroad vehicle typically involves a knuckle that is pivotally mounted on the coupler, usually on spaced-apart pivot lugs at the head of the coupler and on the side opposite the guard arm side. A pivot pin extends through a pair of pivot bores respectively provided in the coupler pivot lugs and attaches the knuckle by securing the pin through the pin hole of the knuckle. The knuckle may pivot between positions while remaining installed on the coupler. A coupler typically has a cavity in the coupler head that includes a floor wall section with a pivot pin hole to receive a trunnion of a knuckle thrower. A knuckle thrower has two oppositely extending legs used to pivot the knuckle as a result of the tilting movement of a lock. The knuckle thrower is usually a cast or forged component, and is irregularly shaped. The coupler head includes a lock-receiving chamber. A lock is disposed in the chamber. The lock generally includes a lock body and a lock leg depending therefrom. The lock also has a lock set seat which rests on top of the thrower.
A lock lift is also part of the arrangement used to regulate the operation of the knuckle. A lock lift is installed at the lower portion of the coupler head cavity, and is used to regulate the position of the lock. The lock lift has a jaw or hook that is supported on a trunnion of the coupler head. The lock lift also includes a linked toggle pivotally connected to a connector or lever. The lock lift hook preferably also is connected to the lever so the hook is mounted at one pivot location on the lever and the toggle is mounted at another pivot location on the lever. The lock lift toggle opposite its lever connected end carries a trunnion thereon. The lock lift trunnion is received in a slot of the lock leg. The knuckle thrower is pivotally supported on the coupler head usually with the trunnion of the thrower seated in a bore of the coupler head. The thrower is movable with the knuckle to their locked positions. The lock moves relative to the knuckle thrower. The lock is generally movable upwardly in the lock chamber to lock set and thrown positions that correspond with the positions of the knuckle, and the lock is dropped by gravity to its locked position when the knuckle is swung to its locked position.
A knuckle thrower constructed to handle stresses imparted thereon by components of a coupling assembly when the coupling assembly is operated or engaged to regulate the position of a knuckle. The thrower has a stress relief mechanism. According to some preferred embodiments, a stress relief zone or area is configured with one or more features for improving the stress handling of the thrower when engaging another coupling assembly component or handling load forces.
According to preferred embodiments, the thrower is constructed for use in a standard coupler assembly, where a lock, lock lift, knuckle and coupler head are arranged with the thrower to regulate the knuckle operation between locked, lock set and unlocked (or thrown) positions.
According to preferred embodiments, a stress relief zone is provided between the knuckle actuating leg and the leg lock seat. According to some embodiments, the stress relief area includes a relief feature, such as an inwardly directed recess. According to some preferred embodiments, the inwardly directed recess is a radial segment formed in a wall of the thrower, which in accordance with a preferred embodiment, is provided in the front wall. According to some embodiments, the stress relief feature may include a supporting member, such as, for example, a hub or rib provided in a stress relief area. The thrower may be constructed with one or more additional ribs, such as, an adjacent rib provided along an upper or lower thrower surface. According to some preferred embodiments, the stress relief zone preferably may include one or more cavities provided in an upper or lower wall of the thrower.
According to some embodiments, the thrower may include one or more of the stress relief features, for example, a combination of one or more recesses, cavities and ribs, and preferred embodiments may include a recess in the front, a cavity in an upper or lower wall, and a hub or rib also in an upper or lower wall. According to some preferred embodiments, stress relief features are disposed in a cooperative relationship. The stress relief features may cooperate to handle or distribute forceloads received on the leg lock seat and knuckle actuating leg.
It is an object of the invention to provide a thrower for a coupling system that has improved stress handling and resistance to failure and breakage.
It is a further object of the invention to accomplish the above objects, providing an improved knuckle thrower which also meets or exceeds AAR standards for knuckle throwers.
Referring to
As illustrated in
Referring to
The knuckle thrower 10 includes a lower trunnion 13 and an upper pivot structure or trunnion 14. The lower trunnion 13 is supported within a lower thrower bore provided on the coupler head 100, while the upper trunnion 14 is supported on an upper trunnion bearing surface of the coupler 100. The trunnions 13,14 freely rotate on the coupler head 100 permitting the knuckle thrower 10 to pivot about the center lines of the trunnions 13,14. The knuckle thrower 10 is cooperatively engaged with the lock 105. As shown in
The thrower 10 is shown in accordance with a preferred embodiment having a stress relief feature. According to some preferred embodiments, the stress relief feature includes a stress relief area or zone 60 provided in proximity to the location where the knuckle actuating leg 11 and the leg lock seat 12 join. According to some embodiments, the stress relief area 60 includes a relief feature, such as, for example, a recess 50. Preferably, the recess 50 is provided in a perimeter wall or surface of the thrower 11, such as, for example, the front surface 52. As illustrated in the drawing figures, the knuckle actuating leg 11 joins with the leg lock seat 12 at a joining location. In accordance with a preferred embodiment, the stress relief means is provided at the joining location. According to the embodiment illustrated, the knuckle actuating leg 11 has a first end 11a and a shoulder 11b at the other end thereof where the leg lock seat 12 joins with the knuckle actuating leg 11. A relief zone 60 is provided along the front 52 of the thrower 10. One preferred embodiment illustrates the relief zone 60 provided between the shoulder 11b and the leg lock seat 12. The recess 50 or a portion thereof may extend into the shoulder 11b and/or the leg lock seat 12. According to a preferred embodiment, the relief zone 60 is provided with an inwardly disposed recess 50. The recess 50 is illustrated in a preferred configuration formed as a radial segment in the front face 52 of the thrower 10, with the radial segment forming a portion 51 of the thrower front face 52 (
According to some preferred embodiments, the maximum wall thickness of the thrower preferably is from between about 0.25 inches and 1.25 inches. According to a preferred embodiment, the maximum thickness of a wall forming the thrower 10, including the thickness of the front face 52 (between the top surface 11c and lower surface 11e) preferably has a maximum thickness of about 1.25 inches. According to some preferred embodiments, where the maximum thickness is about 1.25 inches, the cavity 55 preferably is located below the hub 16 or a portion thereof to provide an area of reduced thickness in the body 11c so that the hub wall and reduced body thickness preferably are within the maximum thickness of 1.25 inches. Each of the upper pivot structure or trunnion 14 and lower trunnion 13 is shown raised relative to the respective thrower top surface and thrower bottom surface. For example, the hub 16 is raised from the upper surface and may support the upper trunnion or pivot structure. In the embodiment illustrated, the cavity 55 is provided in the surface opposite of the hub 16. The raised hub 16 and cavity 55 preferably define a wall segment of the thrower wall having a wall thickness. According to preferred embodiments, the thrower, including the wall segment may be constructed to have the wall thicknesses, as described herein. According to one preferred embodiment, the maximum wall thickness of the thrower walls may be less than about 1.25 inches. According to preferred embodiments, the thrower wall thickness may extend between the top and bottom surfaces, inclusive of structure raised therefrom, such as, for example, the upper trunnion 14 and lower trunnion 13. In the embodiment illustrated, the cavity 55 and raised portion, such as, for example, the hub 16 and upper trunnion or pivot structure 14, are disposed in a cooperative relationship to maintain a desired wall thickness for the thrower 10. According to a preferred embodiment, the wall thickness may be constructed having a maximum thickness which is defined based on an equivalent spherical diameter. According to a preferred embodiment, the thickness may be defined as the diameter of a sphere that would occupy the thrower 10. For example, where the maximum thickness is 1.25 inches, then a sphere having a diameter of 1.25 inches would be the maximum that would fit within the volume taken up by the thrower 10 (including the thrower surfaces). According to a preferred embodiment, where the maximum thickness of the thrower 10 is 1.25 inches, then a sphere having a diameter larger than 1.25 inches would be outside of the volume taken up by the thrower 10. Conversely, spheres having diameters less than 1.25 inches would fit within the volume of the thrower 10, and, according to preferred embodiments, the thrower 10 may have a minimum wall thickness. For example, the minimum wall thickness may be specified to be no less than about 0.25 inches, where a sphere having a diameter of at least 0.25 inches is the minimum. For example, according to a preferred embodiment, the thrower 10 is constructed with a wall thickness that would permit a sphere of 0.25 inches to fit within the volume of the thrower 10. According to some embodiments, the maximum equivalent spherical diameter may be up to five times the minimum equivalent spherical diameter. According to some preferred embodiments, the range for the sphere diameter for spheres that fit within the thrower volume is from about 0.25 to about 1.25 inches.
According to some embodiments, the thrower 10 may be constructed from Grade E steel or ductile iron, and according to some preferred embodiments, the thrower 10 may be constructed from an austempered metal, such as, for example, austempered steel, austempered alloy steel, as well as other austempered metals, and austempered metal alloys. According to a preferred embodiment, the thrower 10 is constructed from austempered ductile iron. The ductile iron from which the thrower 10 is formed, may include austempered ductile iron that comprises ductile iron alloyed with one or more metals selected from the group consisting of nickel, molybdenum, manganese, copper and mixtures thereof. According to preferred embodiments, the metal, such as, for example, according to a preferred embodiment, ductile iron used to produce the thrower 10, may be treated by a treatment process, and preferably a process to strengthen the material, and to provide a suitable microstructure in the formed thrower 10. According to preferred embodiments, the treatment process preferably involves an austenitizing process, by which the formed thrower 10 is an austempered material, and more preferably, austempered ductile iron (ADI). For example, the forming of the thrower 10 may involve applying a suitable austenitizing process to a formed ductile iron thrower, (e.g., a casting or other method of forming the thrower 10). One preferred method involves heating the thrower casting (or other produced thrower, if not produced from a casting) in a heat extraction composition, such as, for example, a molten salt bath, to austenitizing temperature and holding the bath at an austenitizing temperature so as to dissolve carbon in austenite, followed by quenching (which preferably is rapidly done) to avoid pearlite formation, and holding the thrower at an austempering temperature in the molten salt bath. The isothermal transformation to ausferrite preferably takes place to provide an austempered ductile iron thrower 10. According to alternate embodiments, austempered ductile iron (ADI) may include ductile iron alloyed with one or more metals, such as, for example, nickel, molybdenum, manganese, copper and mixtures thereof.
Referring to
These and other advantages may be realized with the present invention. While the invention has been described with reference to specific embodiments, the description is illustrative and is not to be construed as limiting the scope of the invention. For example, although the standard type-E coupler or portion thereof has been shown in the drawings for illustrative purposes, the inventive knuckle lock lift may be used in conjunction with other couplers, such as, for example, type-F couplers. In addition, the thrower preferably is constructed from a suitable material, which, for example, may be Grade E steel, and which, according to preferred embodiments may be austempered metal, and more preferably, austempered ductile iron (ADI). The thrower may be formed by any process, including molding, casting, forging or other process. The knuckle thrower also may be constructed having radiused edges along its perimeter. The dimensions and thicknesses of the knuckle thrower preferably are such that the knuckle throwers according to the invention, such as the knuckle thrower 10 shown and described herein, may be used in standard coupling assemblies with other standard components, such as, for example, knuckles, locks and lock lifts. The improved thrower 10 preferably is interchangeable with prior throwers, and knuckle throwers according to the invention may meet or exceed AAR standards for knuckle throwers. Various modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention described herein and as defined by the appended claims. It is intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.