Hook-type coupler

Abstract: A hook-type coupler for attachment to an end of a railway transit vehicle for joining adjacent ends of a pair of railway transit vehicles, wherein the hook-type coupler has a hook member (20') pivotally mounted therein being pivotal between a latch position and an unlatch position, and adapted to engage a second pivotally mounted hook member in a second hook-type coupler of compatible design, and includes an uncoupling cam (50) for forcibly pivoting the hook member (20') to the unlatch position, and a roller (54) rotatably secured to the uncoupling cam (50) to rollably engage a surface of the hook member (20') when the uncoupling cam (50) is activated through a partial rotation thereby pivoting such hook member (20') to the unlatch position without significant sliding frictional engagement between the uncoupling cam (50) and the hook member (20').

Description: FIELD OF THE INVENTION This invention relates generally to what is known in the art as hook-type couplers, as used to mechanically join adjacent disposed ends of a pair of railway passenger transit vehicles, such as electric trolleys and subway cars. More particularly, this invention relates to a unique and improved, uncoupling cam as incorporated within a pneumatically, electrically or hydraulically operated hook-type coupler whereby the uncoupling cam includes a roller at its biasing edge to significantly reduce friction at the interface of the uncoupling cam and hook member, which not only results in a smoother, non-binding camming action to significantly reduce wear of the interacting surfaces of the cam and hook member to prolong their life, but further renders a "grease-less" characteristic to the coupler to thereby eliminate problems resulting from the presence of grease and periodic maintenance. BACKGROUND OF THE INVENTION It is generally well known that most light rail passenger transit vehicles, such as trolleys, subway cars, and the like, are capable of being independently operated as a single passenger transit vehicle and are often operated as a single vehicle, particularly, during times when passenger travel is at a low volume. It is also generally well known that there are times when such transit vehicles are operated as a unit of two, three, or even more such transit vehicles joined together, particularly, during times of high volume passenger travel, such as the morning and evening "rush hours". Accordingly, in order to permit the operation of such multiple car units, such transit vehicles must be provided with a coupling means at their forward and rearward ends for selectively joining and un-joining the transit vehicles together as the needs change. Most railway passenger transit vehicles of the prior art have utilized simple "hook-type" couplers for joining the adjacent ends of one such vehicle to another, which are pneumatically, electrically or hydraulically operated to uncouple the coupler incident to the disjoining of such joined adjacent ends of railway transit vehicles. That is to say, the coupler hooks are normally spring biased to a coupling position, so that when the coupler on one transit vehicle is brought into contact with another, the coupler hooks will automatically engage each other to effect a coupling. The pneumatic, electric or hydraulic control incorporates responsive hardware that merely re-positions the engaged hooks so that the two transit vehicles are not coupled together, thereby permitting either one of the transit vehicles to be driven away from the other. Hook type transit couplers utilize a pivotal hook disposed within a gathering core recessed within a coupler head, and includes a biasing spring to bias the pivotal hook to closed or latch position. Therefore, when a pair of such coupler heads, one each attached to an end of a transit vehicle, are brought into contact, the gathering cores are aligned so that the hook in each gathering core will engage the hook in the other gathering core to physically lock the two coupler heads together. Each gathering core includes an externally operated, rotatable unlatching cam adapted to pivot each hook away from the other hook to an unlatch position for purposes of uncoupling a pair of joined transit vehicles. Because the rotatable uncoupling cam is triangular in form, a considerable degree of friction results between the working edge of the rotatable uncoupling cam and the hook member side surface against which the cam is acting. Because the action is entirely a sliding action, a considerable degree of wear results not only to the active, camming surface of the uncoupling cam, but also to the side surface of the hook member. To minimize such wear and to assure that the cam is freely rotatable, it is common practice to pack sufficient lubricant; i.e., grease, into the gathering core and particularly around the uncoupling cam to lubricate the frictional contacting interface surfaces. Since the outward end of any uncoupled transit vehicle will naturally have an unused coupler, the gathering core in such an unused coupler will be exposed to the elements, including dust, dirt and debris, which will be attracted to and contained within the grease packing within the gathering core. Such contaminated grease will, of course, adversely affect the operation of the coupler and particularly the rotatable cam, often contributing to wear which the grease is intended to minimize, and even preventing proper operation of the uncoupling cam. Therefore, proper preventative maintenance requires that the gathering cores be periodically wiped and cleaned of old contaminated grease and replaced with fresh clean grease. SUMMARY OF THE INVENTION This invention is predicated upon our conception and development of a new and improved pneumatically, electrically or hydraulically operated hook-type coupler, and particularly a new and improved, uncoupling cam therein which includes a rotatable roller mounted thereto which is disposed at a location to be biased and rotated against the adjacent coupler hook member thereby greatly reducing, if not completely eliminating the sliding frictional forces between the uncoupling cam and coupler hook member. The reduced frictional forces will not only provide a smoother operation to the camming action and prolong the life of the two main wear components (the cam and hook member) and better assure their continued proper operation, but will further eliminate the need for any lubricant, such as grease, to render a "grease-less" characteristic to the coupler. In essence, the subject invention is directed to a hook-type coupler for attachment to an end of a railway transit vehicle for joining adjacent ends of a pair of such railway transit vehicles, which like prior art hook-type couplers includes a coupler head having a gathering core, with a hook member pivotally mounted within the gathering core, and being pivotal between a latch position and an unlatch position, and of course, is adapted to engage a second pivotally mounted hook member in a second hook-type coupler of compatible design, when the gathering cores are brought into contact. The physical structures of each coupler must be compatible to the extent that a protruding end of each pivotal hook member will pass into the gathering core of the other coupler while such hooks members are pivoted to said latch position, and the two hook members spring biased so that they will close on and engage each other to lock the two respective transit vehicles together. To that end, the coupler of this invention, like those of the prior art, must include a biasing means within the gathering core for pivotally biasing the pivotally mounted hook member to the latch position. Like prior art couplers, the coupler of this invention further includes an uncoupling cam within the gathering core for overcoming the biasing means to selectively pivot the hook member to the unlatch position, and an externally operated actuator to selectively rotate the uncoupling cam through an angle sufficient to pivot the hook member to the unlatch position, to thereby uncouple the two hook members and, accordingly, permit uncoupling of the joined transit vehicles. Unlike the prior art, however, the uncoupling cam of this invention is provided with a roller at the edge thereof contacting the hook member to eliminate, or at least greatly minimize, sliding friction at the interfaces between the uncoupling cam and the hook member, which not only provides a smoother operating cam and significantly reduced wear on the uncoupling cam and hook member to greatly increase their life but also eliminates, or at least greatly reduces, the need for a lubricant to render a "grease-less" characteristic to the coupler. OBJECTS OF THE INVENTION Accordingly, it is a primary object of this invention to provide a new and improved uncoupling cam for use in all hook-type couplers for use on railway passenger transit vehicles whereby the uncoupling cam is provided with a roller for contacting and pivoting the coupler hook member to an unlatch position. Another primary object of this invention is to provide a new and improved pneumatically, electrically or hydraulically operated hook-type coupler having a new and improved uncoupling cam therein which eliminates or substantially reduces sliding frictional forces between the cam and coupler hook member. A further object of this invention is to provide a pneumatically, electrically or hydraulically operated hook-type coupler for use on railway passenger transit vehicles which includes an uncoupling cam provided with a roller for rollably contacting and pivoting the coupler hook member to an unlatch position thereby eliminating or reducing sliding frictional forces between the cam and coupler hook member. Still another object of this invention is to provide a pneumatically, electrically or hydraulically operated hook-type coupler for use on railway passenger transit vehicles which includes an uncoupling cam provided with a roller for rollably contacting and pivoting the coupler hook member to an unlatch position thereby significantly reducing wear on the contacting surfaces of the uncoupling cam and coupler hook member. An even further object of this invention is to provide a pneumatically, electrically or hydraulically operated hook-type coupler for use on railway passenger transit vehicles which includes an uncoupling cam provided with a roller for rollably contacting and pivoting the coupler hook member to an unlatch position to thereby render a "grease-less" characteristic to the hook-type coupler. These and other objects and advantages of this invention will become apparent after a full reading of the following detailed description, particularly, when read in conjunction with the attached drawings as described below. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional plan view of a pair of spaced prior art coupler heads with both hook members in the latch position as necessary to be coupled together. Figure 2 is another schematic cross-sectional plan view of a pair of prior art coupler heads identical to Figure 1, but instead showing the couplers in the joined together condition. Figure 3 is again another schematic cross-sectional plan view of a pair of prior art coupler heads like Figures 1 and 2, but instead shows the uncoupling cam in the activated position with the hook members unjointed to permit uncoupling of the two coupler heads. Figure 4 is a side view of an uncoupling cam in accordance with a presently preferred embodiment of this invention. Figure 5 is a partial cross-sectional plan view of a pair of coupler heads each including a roller equipped uncoupling cam as illustrated in Figure 4. DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Prior to proceeding with a detailed description of the subject invention, it is noted that for the sake of clarity, identical components which have identical functions have been identified with identical reference numerals throughout the several views of the attached drawings. Reference to Figures 1-3 will illustrate in cross-section, a pair of prior art electrically operated hook-type couplers for attachment to an end of a railway transit vehicle for joining together adjacent ends of a pair of such railway transit vehicles. Such prior art couplers normally comprise a coupler head, generally designated 10, having a shank portion 12 for connecting the coupler head 10 to a frame member (not shown) of a transit vehicle (not shown). The coupler head 10 includes a gathering core 14, which in essence comprises a cavity in a flat, forward face 16 of the coupler head 10. A hook member 20 is pivotally mounted for partial rotation on pivot pin 22 within gathering core 14, and is suitably disposed to one side of gathering core 14 so that the exposed portion of a comparable hook member 20A, from another compatible coupler head 10A, can be inserted into the gathering core 14 to engage hook member 20. In a like manner and at the same time, the exposed portion of hook member 20 will be inserted within gathering core 14A so that hook members 20 and 20A engage each other to effect the desired coupling, as shown in Figure 2. In contrast to Figures 1 and 2, Figure 3 illustrates the same components, wherein the uncoupling cam 32 has been activated by a partial rotation thereof to pivot hook members 20 and 20A outwardly and away from each other to the unlatch position. As can be seen by contrasting Figures 1 and 2 with Figure 3, hook member 20, as pivotally mounted on pin 22, is pivotal between a latch position as illustrated in Figures 1 and 2, and an unlatch position as illustrated in Figure 3. A biasing means 24, such as a composite multiple leaf spring as shown, is also secured within gathering core 14 for purposes of biasing hook member 20 to the latch position as illustrated in Figures 1 and 2, whereby flat surface 26 of hook member 20 is biased against an elongated, flat, side surface 34 on uncoupling cam 32. As noted above, also mounted within gathering core 14 is uncoupling cam 32, which is partially rotatable for forcibly pivoting the hook member 20 to the unlatch position as illustrated in Figure 3, thereby overcoming the biasing action of biasing means 24 and moving hook member 20 to the unlatch position where it will not and cannot be latched to an adjacent hook member 20A. As can be seen in Figure 3, the uncoupling cam 32 biases each of the hook members 20 and 20A away from each other to an extent that they no longer engage each other, thereby permitting the transit vehicles to be separated. Also included is a pneumatically, electrically or hydraulically operated actuator (not shown), which functions to externally operate the uncoupling cam 32; i.e., partially rotating cam 32, to selectively pivot hook member 20 to the unlatch position as shown in Figure 3, permitting the hook members 20 and 20A to become unlatched, thereby effecting an uncoupling of the joined coupler heads 10 and 10A, as well as permitting an uncoupling of the transit vehicles (not shown) to which the couplers are attached. Actuators (not shown) for partially rotating uncoupling cam 32 are well known to those familiar with the subject art and need not be described here, suffice it to note that such actuators (not shown) are not normally disposed within the gathering core 14, but are normally attached to the outer surface of the coupler head 10, and are linked to partially rotate pin 52 to which uncoupling cam 32 is rigidly attached. An example of such an actuator is disclosed and described in U.S. Patent No. 5,499,728, assigned to the assignee of this invention, which can be either electrically or manually operated. Accordingly, U.S. Patent No. 5,499,728 is incorporated herein by reference. With regard to the prior art uncoupling cam 32 as illustrated, and again contrasting Figures 1 and 2 with Figure 3, the action of uncoupling cam 32 can be seen. Specifically, in the latch position (Figure 1), no rotating force is applied to uncoupling cam 32 so that flat surface 26 on hook member 20 is biased against an elongated, flat, side surface 34 on cam 32. For uncoupling, cam 32 is used to pivot hook member 20 to the unlatch position (Figure 3). Cam 32 must be rotated counter-clockwise so that uncoupling cam 32 will force the hook member 20 outwardly, against the biasing action of spring means 24 until curved surface 36 on uncoupling cam 32 engages flat surface 26 on hook member 20. As shown in Figure 3, when both hook members 20 and 20A are pivoted to the unlatch position, they no longer engage each other and, accordingly, the coupler heads 10 and 10A are no longer joined together, which thereby permits one transit vehicle to be driven away from the other. When the coupler heads 10 and 10A are withdrawn from each other so that the two transit vehicles (not shown) are no longer joined together, the actuator (not shown) can be deactivated, permitting biasing means 24 to pivotally bias hook member 20 back to the latch position. If for some reason cam 32 becomes stuck in the rotational position where hook member 20 is pivoted to the unlatch position, it can be seen in Figure 3 that any effort to again join together a pair of coupler heads 10 and 10A will cause hook member 20A to contact flat surface 38 on cam 32, thereby forcing rotation of cam 32 as necessary to disengage hook member 20 from the unlatch position, allowing it to return to the latch position by the force of biasing means 24. While flat surface 38 on uncoupling cam 32 does not otherwise function in the camming. action of uncoupling cam 32, the flatness and angle thereof with regard to the other surfaces 34 and 36 is critical only to the extent that it must not interfere with movement of hook member 20A when the two hook members 20 and 20A are closed together as shown in Figure 2. As should be apparent from Figure 2, any outward extension thereof could prevent the hook member 20 or 20A from fully engaging the other hook member 20 or 20A, to prevent a proper engagement of the two hook members. The crux of this invention resides in the inventive uncoupling cam 50 as illustrated in Figures 4 and 5. Reference to Figure 4 will illustrate a side view of the inventive uncoupling cam 50 in accordance with a presently preferred embodiment of this invention, while reference to Figure 5 illustrates in partial cross-section, a pair of couplers 10', each having a gathering core 14' with abutting forward faces 16'. Each gathering core 14' contains a pivotal hook member 20' pivotally attached to a pin 22' with each biased toward the latch position by a biasing means such as a multiple leaf spring 24'. Each gathering core 14' includes an uncoupling cam 50 of this invention (only one of which is shown in cross-section), which is rigidly attached to pivot pin 52', and as can be seen, uncoupling cam 50 is substantially the same as prior art uncoupling cam 32 except for the fact that it includes roller 54 transversely disposed at the intersection of surfaces 34' and 36', such that each of surfaces 34' and 36' is generally tangent with a cylindrical side of roller 54. Accordingly, roller 54, in essence, replaces the sharp angled intersection of surfaces 34 and 36 of the prior art uncoupling cam 32. As can be seen in Figure 4, the inventive uncoupling cam 50 does include a pivot bushing 64 pivot pin 52' as well as surfaces 34', 36' and 38' which in essence function like pivot pin 52 and surfaces 34, 36 and 38 on prior art uncoupling cam 32. While not a part of this invention, Figure 5 also shows a lever arm 56 within each gathering core 14' which is rigidly attached to cam 50, so that an actuator (not shown) acting through lever arm 56 will partially rotate uncoupling cam 50 to the unlatch position as illustrated in Figure 5. As previously noted in discussing the prior art, the actuator (not shown) and the interconnecting lever arm 56 may or may not be positioned within gathering core 14 or 14', and most commonly, both are disposed on the outer surface of coupler head 10, as shown in the above-referenced patent. Having described in detail a presently preferred embodiment of this invention, it should be apparent that other embodiments could be utilized and modifications incorporated without departing from the scope of the invention. For example, it should be quite apparent that the uncoupling cam 50 could take different forms depending on the design and configuration of the specific coupler to which it is incorporated. An irregular, circular form typical of most cams could be developed. In addition, the coupler head and gathering core as described in the above specification could take any one of a number of differing designs including designs which may completely eliminate a gathering core.

Claims: A hook-type coupler for joining adjacent ends of a pair of railway transit vehicles, said hook-type coupler comprising: (a) a coupler head (10'); (b) a hook member (20') pivotally mounted to said coupler head (10'), said hook member (20') being pivotal between a latch position and an unlatch position, said hook member (20') engageable with a second hook member (20A') pivotally mounted to a second coupler head (10A') of a second hook-type coupler when said coupler head (10') is mated with said second coupler head (10A') of said second hook-type coupler, and both of said pivotally mounted hook members (20' and 20A') are pivoted to said latch position; (c) a biasing means (24') attached to said coupler head (10') for pivotally biasing said hook member (20') to said latch position; (d) an uncoupling cam (50) rotatably attached to said coupler head (10') for forcibly pivoting said hook member (20') to said unlatch position; and characterized by : (e) a roller (54) rotatably secured to said uncoupling cam (50) for rollably engaging a surface of said hook member (20') when said uncoupling cam (50) is partially rotated thereby pivoting said hook member (20') to said unlatch position with a minimum of sliding frictional engagement between said uncoupling cam (50) and said hook member (20'). A hook-type coupler, according to claim 1, wherein said uncoupling cam (50) is a solid body secured to a pivot pin (52') and is at least partially rotatable on said pivot pin (52') to effect said forcible pivoting of said hook member (20') to said unlatch position. A hook-type coupler, according to claim 2, wherein said roller (54) is rollable on an axis of rotation parallel to an axis of rotation of said pivot pin (52'). A hook-type coupler, according to claim 1, wherein said uncoupling cam (50) is a solid body having a uniform polygonal cross-section with at least two oblique side surfaces (34' and 36') tangent to said roller (54). A hook-type coupler, according to claim 3, wherein said solid body of said uncoupling cam (50) has a uniform generally triangular cross-section with at least two oblique side surfaces (34' and 36') tangent to said roller (54). A hook-type coupler, according to claim 3, wherein said solid body of said uncoupling cam (50) has a uniform triangular cross-section with two oblique side surfaces (34' and 36') tangent to said roller (54) such that a first (34') of said oblique side surfaces will abut against said hook member (20') when said hook member (20') is in said latch position, and a second (36') of said oblique side surfaces will abut against said hook member (20') when said hook member (20') is in said unlatch position. A hook-type coupler, according to claim 1, including a gathering core (14') formed within said coupler head (10') wherein: (a) said hook member (20') is pivotally mounted; (b) said biasing means (24') is attached; and (c) said uncoupling cam (50) is rotatably attached. A hook-type coupler, according to claim 7, wherein said uncoupling cam (50) is a solid body secured to a pivot pin (52') and is at least partially rotatable on said pivot pin (52') to effect said forcible pivoting of said hook member (20') to said unlatch position. A hook-type coupler, according to claim 8, wherein said roller (54) is rollable on an axis of rotation parallel to an axis of rotation of said pivot pin (52'). A hook-type coupler, according to claim 7, wherein said uncoupling cam (50) is a solid body having a uniform polygonal cross-section with at least two oblique side surfaces (34' and 36') tangent to said roller (54). A hook-type coupler, according to claim 9, wherein said solid body of said uncoupling cam (50) has a uniform generally triangular cross-section with at least two oblique side surfaces (34' and 36') tangent to said roller (54). A hook-type coupler, according to claim 9, wherein said solid body of said uncoupling cam (50) has a uniform triangular cross-section with two oblique side surfaces (34' and 36') tangent to said roller (54) such that a first (34') of said oblique side surfaces will abut against said hook member (20') when said hook member (20') is in said latch position, and a second (36') of said oblique side surfaces will abut against said hook member (20') when said hook member (20') is in said unlatch position.

Inventors: GRAU CURTIS A, RUMSEY STEVEN C, GRAU, CURTIS A., RUMSEY, STEVEN C.
Applicants: WESTINGHOUSE AIR BRAKE CO, WESTINGHOUSE AIR BRAKE COMPANY
Application year: 1998
Main classification: B61G3
IPC codes: B61G3