GB2092537A - Railway car coupler having an improved thrower - Google Patents

Abstract

A railway car coupler is disclosed as having a knuckle thrower 10 with an improved blunted tip 16, as distinguished from the more pointed tip of a conventional AAR Standard thrower for either an E or F-type coupler. The improved tip causes an increase in the moment arm of the knuckle as the knuckle is rotated by the thrower from a closed to an open position. The invention is particularly applicable to an F-type coupler. <IMAGE>

Description

SPECIFICATION Railway car coupler having an improved thrower This invention relates to a railway car coupler.

The invention is particularly well suited for use with railroad car couplers, especially Ftype couplers. Both E and F type couplers employ a thrower which is designed to engage a thrower pad on the knuckle and rotate the knuckle from a normally closed position to a fully open or extended position where the knuckle is free to become interlockingly engaged with the knuckle of an opposing coupler.

The configuration of the tip of the thrower is critical in the function of the thrower to rotate the knuckle easily without becoming hung-up on the knuckle or disengaged from the retaining lug that is provided in the coupler head to maintain the thrower in position.

The thrower can become disengaged from the retaining lug, if it is allowed to rotate to a point where there is inadequate overlap between the lug and adjacent portion of the thrower. Once the restraint of the lug is removed, the thrower is free to move to a position where it can become hung-up on the lug and prevent rotation of the knuckle from an open to a closed position. The tip of the thrower must also be specially shaped so that the tip will not become hung-up against the thrower pad of the knuckle upon completion of its stroke to prevent rotation of the knuckle from an open to a closed position. These are but a few of the problems encountered in the design of a knuckle thrower.

There appears to be no serious problem encountered during the initial actuation and operation of the linkage which is used to rotate the knuckle thrower which, in turn, rotates the knuckle. However during rotation the knuckle meets with stiff resistance forces which disrupt the smooth operation of the thrower and linkage. The invention is defined in the claims and aims to increase the moment arm of the knuckle without adversely affecting the moment arm of the thrower during operation or rotation of the knuckle to overcome this resistance.

Briefly stated, the invention as specifically described and illustrated herein resides in a railroad car coupler that comprises a coupler head and shank, the couper head including (I) a knuckle that is rotatable about an axis and has a thrower pad, and (II) a thrower for engaging the pad and rotating the knuckle from a normally closed position to an open position.The coupler is characterized by a shortened and blunted pad engaging tip on the thrower, compared to the longer, more pointed tip of an AAR standard thrower of an AAR standard F coupler, to increase the moment arm of the knuckle, i.e. the distance between the rotational axis of the knuckle and point of contact of the tip with the pad, by about 1/2 inches at a point about midway of the pathway that the tip travels to rotate the knuckle from a closed to an open position, and thereafter maintain a substantial increase in the moment arm as the knuckle and thrower finish their strokes, without seriously affecting the overlap of the retainer lug with the adjacent portion of the thrower, when the thrower is fully rotated or has completed its stroke.

Thus, the normally shorter moment arm at which the rotating force is applied against the knuckle by the thrower, is considerably lengthened to produce a maximum increase in the ratio of the moment arms of the knuckle and thrower by about 30%, without adversely affecting the longer moment arm of the thrower and, more importantly, without causing disengagement of the thrower from the retainer lug of the coupler head.

The invention will be better understood from the following description given with reference to the accompanying drawing, in which like parts are represented by like reference numerals and in which: Figure 1 is a plan view of a known AAR standard F-type coupler head, in section, with portions removed to show the knuckle and thrower; Figure 2 is a plan view of a thrower that is made in accordance with one embodiment of the invention; and Figure 3 is a plan view of another thrower which is made in accordance with a second embodiment of the invention.

Fig. 1 shows an AAR standard F-type railway car coupler 5 having a coupler head 6 and attached shank 7. A hollowed out chamber 8 is formed within the coupler head 6, and is designed to receive various components of the coupler, such as a knuckle 9 and a knuckle thrower 10 which rotate in horizontal planes about a pair of parallel, vertical pivot pins 11 and 12, when the coupler 5 is in a normally horizontal position.

The coupler head 6 is provided with a retainer lug 1 3 which is designed to overlap an adjacent portion 14 of the thrower 10, when the thrower 10 is in an unrotated rest position where the knuckle 9 is in a normally closed position, as seen in heavy line in Fig.

1, and when the thrower 10 is fully rotated, i.e. completed its stroke to move the knuckle 9 to a normally open position, as seen in dotted line. The lug 1 3 retains the thrower in proper position within the chamber 8 of the coupler head 6.

The knuckle thrower 10 is provided with a knuckle actuating leg that has a distal end or tip 1 6 which is designed to engage an adjacent thrower pad 1 7 that is formed on the knuckle 9 between the pivot pinhole 1 8 and tail 1 9 of the knuckle 9.

As previously indicated, the shape of the tip 16 of the knuckle thrower 10 is critical to: (I) the smooth operation or rotation of the knuc kle, (II) the prevention of any hang up between the thrower and knuckle, and (lli) the maintenance of the necessary overlap between the retainer lug 13 of the coupler head 6 and adjacent portion 14 of the thrower 10, when the thrower is in a fully rotated position where the knuckle 9 is in an open position.

With particular reference to Fig. 2, there is shown an improved knuckle thrower 10 which is characterized by a tip 16 which is shortened a distance D of about 1/4 inch (6.35 mm) and substantially blunted, as compared to the longer and more pointed tip (shown in dotted line) of a conventional thrower that is presently used with an AAR standard F coupler. The improved knuckle thrower 10 is best described in relation to the X-X and Y-Y construction axes which are normally used in the design and construction of a knuckle thrower.

The overall distance D1 of the farthest point of the improved blunted tip 16 from the Y-Y construction axis is 6-5/8 inches (168 mm) which is about 1/8 inch (3.2 mm) shorter than the corresponding measurement of the existing AAR standard F knuckle thrower.

Moreover, the distance D2 of the closest point of the blunted tip from the X-X construction axis is 27/32 inch (21.4 mm) which is about 1/16 to 1/8 inch (1.6 to 3.2 mm) greater than the corresponding measurement of the existing F knuckle thrower.

The improved blunted tip 16 has a comparatively slight, compound curvature formed by three successive radii R1 of 1/4 inch (6.35 mm), R2 of 1/2 inch (12.7 mm) and R3 of 5/16 inch (7.9 mm). The first radius R1 merges with the adjacent straight side 20 of the blunted tip closest the X-X axis, and has its centrepoint located on a line which is spaced parallel from the construction line defining the distance D1 a distance D3 of 1/2 inch (12.7 mm). The third successive radius R3 merges with the straight side 21 of the blunted tip farthest from the X-X axis, and has its centerpoint located on a line that is spaced parallel to the X-X construction axis a distance D4 of 1-1/32 inches (26.2 mm.

The second radius R2 is located to merge with the first and third radii R1 and R3. Thus, the blunted tip 16 smoothly merges with the two flat sidewalls 20,21 which converge in the direction of the tip 1 6. The thickness T of the blunted tip 16 of the thrower of Fig. 2 is about 3/4 inch (19.05 mm) or about 1/8 inch (3.2 mm) greater than the correspondingly measured thick.l-ess of ,'he more pointe.l @@ of @@@ existing @@@@@@.

The line 22 of Fig. 1 tepresen,s connected tll :O: ' @ @ iiried 'í;p 'I ee ;lJEIGC dt @@@@@@@ @@ @@ AAR standard F @@@@@@@ with @@@ @@@@@ pad 17 of the krluc- kle 9, as a the knuckle rotates from a closed to an open position, the various positions of the thrower pad during rotation of the knuckle being shown in dotted line. Correspondingly line 23 represents the connected points of contact of the improved blunted tip 16 of the thrower pad 17 of the knuckle.It can be appreciated from a comparison of these two lines 22, 23 that the shorter moment arm of the knuckle, i.e. the distance between the rotary axis of the knuckle and point of contact of the blunted tip with the thrower pad 17, is substantially increased, i.e. by about 9/16 inch (14.3 mm), when the blunted tip 16 is about midway along the pathway which it travels in rotating the knuckle from a closed to an open position. It can be seen that this maximum increase in the length of the moment arm of the knuckle gradually decreases as the blunted tip 16 completes its travel along the pathway to a point where the moment arm of the knuckle is still substantially increased, i.e.. by about 13/64 inch (5.16 -mm), when the knuckle is fully opened.The point of contact of the blunted tip with the thrower pad is substantially the same as that of the more pointed end of a conventidnal thrower, when the thrower is in a rest:position where the knuckle is closed. From this point on, the moment arm of the knuckle increases such that the greatest increase in the moment arm of the knuckle occurs at a point where it is believed the knuckle encounters increased resistance to rotation and is effective in substantially increasing the value of the force exerted by the thrower against the knuckle without radially shortening the moment arm of the knuckle to seriously reduce the value of the force directed against the knuckle by the thrower.

With particular reference to Fig. 3, there is shown another embodiment of the invention, wherein the improved blunted tip 16 has the same thickness as that of a conventional thrower used in an AAR standard F coupler, i.e. the flat sidewalls 20,21 converging toward the tip 16 are identically spaced and sloped. The preferred blunted tip 16 of Fig. 3 is shortened a distance D of about 5/16 inch (7.9 mm) in comparison to the pointed tip of bn existing thrower. The corresponding distances D1 and D2 from the Y-Y and X-X axes are 6-41 /64 inches (168.7 mm) and 15/16 inch (23.8 mm). The blunted tip 16 has a curvature which is similarly formed on three successive radii R1 of 3/8 inch (9.5 mm), R2 of 1/2 inch (12.7 mm) and R3 of 3/16 inch (4.76 mm). The first radius R1 merges with the straight side 20 of the blunted tip closest the X-X axis, and has its centerpoint located on a line which is spaced parallel to the line defining the distance D1 a distance D3 of 13/32 inch (10.3 mm). The third radius R3 merges with the straight side 21 of the blunted tip farthest from the X-X axis and has its centrepoint located on a line that is spaced parallel to the X-X axis a distance D4 of 1-7/32 inch (30.96 mm).

The second radius R2 merges with the first and third radii R1 and R3. The line joining points of contact between the blunted tip 1 6 of Fig. 3 and the thrower pad 1 7 as the knuckle rotates is charted on Fig. 1 as line 24. As seen, there is an initial increase of about 9/64 inch (3.6 mm) over the thrower of Fig. 2, but just beyond 5" of rotation the advantage achieved is slightly less, i.e. 7/16 inch (11.1 mm) compared to 9/16 inch (14.3 mm) measured at the same angle of 25 of rotation and 5/64 inch (1.98 mm) compared to 1 3/64 inch (5. 1 6 mm) measured at the final angle of 60 of rotation or upon complete rotation of the knuckle to a fully open position.The maximum increase at about 25" rotation is about 1/2 inch (12.7 mm) plus or minus 1/16 inch (1.6 mm).

In both cases, the composite curvature of the improved blunted tip merges smoothly with the straight sidewalls 20,21 of the thrower, which sidewalls are free of projections and indentations. In some cases, a short flat surface can be used in combination with the three radii, but in all cases at least three radii are used to form the blunted tip.

As best seen in Fig. 2, the variance in the overlap between the retainer lug 1 3 and adjacent portions 14 and 1 4a of a conventional F thrower and the improved throwers of Figs. 2 and 3, when the throwers are fully rotated, is only about 1/16 to 5/64 of an inch (1.6 to 1.98 mm) which is insufficient to cause any serious problem of the thrower becoming disengaged from the lug.

Thus, there has been provided a highly improved thrower which has a specially configured tip for increasing the moment arm of the knuckle, as the knuckle is rotated from a closed to an open position.

Claims (11)

1. A railroad car coupler comprising a coupler head and shank, the coupler head including a knuckle which is rotatable about an axis and which has a thrower pad and a thrower having a tip between a pair of substantially flat converging sidewalls for engaging the pad and rotating the knuckle from a normally closed position to an open position; the coupler being characterized by a padengaging tip on the thrower between the pair of flat converging sidewalls which is shorter and blunter compared to the longer, more pointed tip of the thrower in a conventional AAR standard F-type coupler, whereby the distance between the knuckle axis and point of contact of the tip with the pad is increased by about one-half inch (about 1 2.7 mm) at the midway region of the pathway that the thrower tip travels to rotate the knuckle from a closed to an open position.

2. The railroad car coupler of claim 1, wherein the blunted tip is shortened by at least one quarter of an inch (6.35 mm).

3. The railroad car coupler of claim 1, wherein the blunted tip has a composite curvature which is formed by at least three radii.

4. The railroad car coupler of claim 3, wherein the second or intermediate radius of the three radii, is greater than the other two radii and wherein the first and third radii smoothly merge with the flat converging sidewalls.

5. The railroad car coupler of claim 4, wherein the overall distance (D) of the farthest point of the blunted tip from the Y-Y construction axis of the thrower is six and fiveeights inches (168 mm).

6. The railroad car coupler of claim 5, wherein the first of the three successive radii, closest the X-X construction axis of the thower, is about one-quarter to three-eights of an inch (6.35 to 9.5 mm) from a centrepoint that is located on a line which is parallel spaced about six and one-eighth inches (155.6 mm) from the Y-Y construction axis, and the third of the three successive radii is three-sixteenths to five-sixteenths inches (4.76 to 7.9 mm) from a centerpoint located on a line which is parallel spaced about one and seven-thirty seconds inches (28 mm) from the X-X construction axis.

7. The railroad car coupler of claim 6, wherein the second, intermediate radius is about one-half inch (12.7 mm).

8. The railroad car coupler of claim 7, wherein the distance of the closest point of the tip of the X-X construction axis is at least twenty-seven/thirty-seconds of an inch (21.4 mm).

9. The railroad car coupler of claims 1 or 8, wherein the increased destance, defined in claim 1, increases substantially steadily from at least a zero difference when the knuckle is in a normally closed position.

1 0. The railroad car coupler of claim 9, wherein the increased distance is at least about one-quarter of an inch (6.35 mm) measured from points located from midway to the end of the pathway which the tip travels in the opening of a closed knuckle.

11. A railroad car coupler substantially as hereinbefore described with reference to Fig.

1 as modified by Fig. 2 or Fig. 1 as modified by Fig. 3 of the accompanying drawings.