US2881927A

US2881927A - Railway coupler guard arm

Info

Publication number: US2881927A
Application number: US473882A
Authority: US
Inventors: Furniss Loree Elwyn
Original assignee: Buckeye Steel Castings Co
Current assignee: Buckeye Steel Castings Co
Priority date: 1954-12-08
Filing date: 1954-12-08
Publication date: 1959-04-14
Anticipated expiration: 1976-04-14

Description

April 14, 1959 L. E. FURNISS RAILWAY COUPLER GUARD ARM 2 sheets-sheet 1 Filed Dec. 8. 1954 INVENTOR' LQIPEE ELM/V MEN 5Q APril14,1}959 L. aFLvRNlss' 2,881,927

RAILWAY COUPLER GUARD ARM Filed Dec. 8. 1954 2 Sheets-Shee t 2 INVENTOR United States Patent RAILWAY COUPLER GUARD ARM Loree Elwyn Furniss, Groveport, Ohio, assignor to The Buckeye Steel Castings Company, Columbus, Ohio I A Application December 8, 1954, Serial No. 473,882

4 Claims. (Cl. 213-151) The present invention relates to railway couplers and to improvements in the guard arm portion of the coupler andmore specifically pertains to the provision of a surface on the inner face of the guard arm so as to avoid the development of destructive stresses in the coupler head during some operating conditions.

The guard arm of existing couplers has been so shaped that it is possible for a partly closed knuckle of one coupler to be wedged between the nOse of a closed knuckle on another coupler and the inner face of the guard=arm of the second coupler as the two couplers move toward each other. The wedging action of the partly closed knuckle as it is thrust between the nose of the knuckle of the other coupler and the guard arm thereof acts outwardly on the guard arm and outwardly on the knuckle side of the coupler head producing stresses within the coupler head having the closed knuckle. The extent of such stresses is dependent on the magnitude and direction of two forces one applied at the inside of the guard arm urging it laterally outward and the other force applied to the knuckle side of the coupler head through the closed knuckle urging the knuckle side of the coupler head laterally outward. These forces are developed as a result of the impact of one coupler with the other as two railway vehicles move toward each other or as one vehicle moves towards a standing car or the like. The stresses developed in the coupler head having the closed knuckle as a result of such an impact force have been found to be sufiicient to cause a break in the coupler head extending rearwardly of the contour in the vicinity of the longitudinal center line of the coupler.

A further disadvantage takes place with a prior type of coupler when the knuckle thereof is in a partly closed condition as it moves into impact engagement with an existing coupler having the knuckle thereof in the closed position. One of the two forces developed upon impact engagement of the two couplers is at right angles to the contacting surfaces of the nose portions of the knuckles and the other force is perpendicular to the contacting surfaces between the heel of the partly closed knuckle and the inner side face of the guard arm. These two forces intersect in such a position that there is no resulting force which would tend to bring the couplers into a more generally aligned relationship with respect to each other. A stable condition results and the impact forces are absorbed by the couplers while they remain in angularly related positions. Accordingly the stresses set up as a result of the impact forces are not well distributed throughout the coupler heads.

It is accordingly an object of the present invention to provide improvements in the shape of the guard arm portion of a railway coupler so that a resulting force will be developed when a partly closed knuckle of one coupler moves into engagement with another coupler having the knuckle in the fully closed position with such resulting force acting in a direction to horizontally shift the two couplers so that the stems thereof are moved towards alignment and to provide clearance at the inner face of the guard arm of a coupler so that the heel portions of both knuckles may engage the respective guard arms on more generally transverse surfaces to distribute the stresses within the coupler heads and accordingly reduce the bending stresses in the contour portion of the coupler head to avoid the development of rupturing stresses which have in some instances in the past caused a breaking of the coupler head.

Another object of the invention is to provide improvements in the shape of the inner face of the guard arm of an interlocking coupler so as to reduce the Wedging action when the nose of the knuckle of one coupler engages the nose of the knuckle of another coupler and to provide a more generally transverse abutting surface for the heel portions of the knuckles so that the forces developed during impact engagement of the two couplers will be transferred from the heel portions of the knuckles to the abutment shoulders thereby reducing the bending stresses and at the same time applying the forces to additional portions of both coupler heads.

A still further object of the invention is to provide improvements in the surface of the inner face of the guard arm of an interlocking coupler so that the heel of a partly closed knuckle moving into engagement with the improved surface will set up a resulting force in cooperation with the engagement of the nose of the partly closed knuckle to develop an unstable condition tending to shift the couplers toward positions where their longitudinal centers are in more general alignment to position the couplers for inter-engagement at a plurality of points or zones whereby the total force of the impact is distributed in both of the coupler heads and applied principally as compressive stresses.

Other objects and features of the invention will be appreciated and become apparent to thOSe skilled in the railway coupler art as the present disclosure proceeds and upon consideration of the accompanying drawings and the following detailed description wherein a railway coupler exhibiting the invention is disclosed.

In the drawings:

Fig. 1 is a plan view of an interlocking coupler embodying the invention.

Fig. 2 is an enlarged fragmentary sectional view of the guard arm side of the coupler taken on the line 2-2 of Fig. 1.

Fig. 3 is an enlarged fragmentary plan view illustrating in greater detail the improved characteristics of the guard arm and guard arm projection.

Fig. 4 is a diagrammatic view illustrating the manner in which a resulting force is developed to provide an unstable condition when two couplers exhibiting the invention move into engagement.

Fig. 5 is a diagrammatic plan view of two couplers embodying the invention showing a condition which follows the relationship depicted in Fig. 4.

Fig. 6 is a view similar to Fig. 4 illustrating the stable condition of two conventional interlocking couplers as they move into engagement.

Referring to the drawings there is shown at 10 a coupler head of the interlocking type which is provided with a knuckle 12 mounted for pivoting movement about a vertically disposed knuckle pin 14. The coupler car ries a guard arm 16 and an aligning wing 17 having a pocket therein is provided at the other side of the knuckle. The major portion of the contour 18 is of the same shape as that of existing interlocking Type F couplers and a shelf 19 extends forwardly of the lower portion of coupler head below the contour 18 in a manner that is known in the art. The nose 21 of the knuckle remains unchanged and the heel portion 22 is of standard construction.

The invention pertains to changes in the inner face of Patented Apr. 14, 1959 ass-1,927

the'guard-arm. 16 in the vicinity of the guard arm projection 23. The inner surface of the guard arm and guard arm projection are formed to have a concave cylindrical surface 26 forwardly of the couplingv line 25 and having a:radius,R--.Which isapproximately equal-to the radius forming the convex cylindrical surface of the heel 22 of they knuckle 12. and is generated about a vertical axis positioned laterally of the-knuckle at such a distance that the.heel of a partly or fully closed knuckle cannot bear against thisconcave surface 26 when the knuckle nose 21 is in contact with the nose of an opposing closed knuckle. In one embodiment the radius R amounts to one and three-quarterinches generated about a vertical axis positioned six and fifteen-sixteenth inches laterally of the center line of the coupler head as indicated at D in Fig; 3; A verticallyextending forward facing shoulder 32. is provided by the cylindrical surface in the area where it.joins; the contour proper and this shoulder is substantially transverse to the longitudinal axis of the coupler head. The juncture between the shoulder 32 and the'contour forms a vertically extending ridge 27. This cylindrical surface 26 extends to the area indicated at 28 where the arcuate surface merges with a substantially straight surface 29 which continues towards the nose portionof the guard arm. The location of the ridge 27 remains unchanged over existing couplers of this type. In oneembodiment the corner 27 is positioned laterally of the 'center line of the coupler head at six and fifty-seven sixty-fourth inches. Thus the center about which the concave surface 26 is generated is positioned a greater distance from the center line of the coupler head than the lateral displacement of the ridge 27. Accordingly the cylindrical surface forms the forward facing shoulder 32 in the-area adjacent the ridge 27. The shape of the inner surface of a corresponding portion of the known Type F coupler is indicated by the phantom line 31 in Fig. 3 and itwill' be observed that the shoulder 32 adjacent the corner 27 is vertical and substantially at right angles to the longitudinal axis of the coupler head 10. While the change in this portion of the contour of the coupler appears to be of a minor character new and advantageous results are'provided as hereinafter described.

The utility of the

guard arm surfaces

26, 29 and 32 of a coupler embodying the present invention will be more apparent upon consideration of Figs. 4 and 5. The couplers shown in Fig. 4 represent a condition which is developed upon contact as two couplers move into engagement when the coupler on the right has its knuckle in the fully closed position and when the knuckle on the coupler at the left is in a partially closed position. The nose of the partially closed knuckle engages the nose of the fully closed knuckle. The heel of the partially closed knuckle engages the ridge 27 of the guard arm of the coupler on. the right. The coupler stem 11 of one coupler is thereby angularly displaced with respect to the stem 11 of the other coupler and a line 36 extending between the two butt bearing surfaces of the coupler stems represents the direction at which'the impact force is applied to the two couplers. Theline 36 is angularly displaced from the longitudinal center line of both couplers. The nose of the partly closed knuckle engages the nose of the coupler carrying the fully closed knuckle at a point or area indicated at 37. The heel portion of the partly closed knuckle engages the ridge of the guard arm of the coupler at the right in Fig. 4 in a zone of the knuckle indicated at 38. The force line 41 is at right angles to the contacting surfaces of the nose portions. The force line 42 is perpendicular to the contacting surfaces at 38. These lines 41 and 42 intersect at 43. This point of intersection is displaced laterally of the line 36. Accordingly a resulting force is developed to move the couplers towards a more aligned relationship than that shown in Fi'gr4 and to move the partially closed knuckle towards a ,closed position. Thus an unstable condition of the couplersexis'ts;

The resultingforceis in such a directionasto shift the couplers towards the aligned condition and the partly closed knuckle swings slightly to a more closed position and the two couplers then assume the relationship shown in Fig. 5. The heel portion 22 of the knuckle carried by the coupler on the right then engages the guard arm of the coupler at the left in thezoneindicated at 46 in Fig. 5. The heel portion 22 of the knuckle carried by the coupler at the left engages'the guard arm 16 of the coupleron the right in. thesame area. Thus the heel por-. tions engage the more "generally transverse abutment surfaces orshoulders 32.0f the respective guard arms and the impact force is thus applied to the guardarms of'both couplers. It willbe observed froma consideration of Fig. 5 that space is provided between the heel portion of each knuckle and the improved contour of each guard arms so as to permit the heel portion of each knuckle to engage theiabutment-surfacesror shoulders 32. Accordingly there is very little wedging actionsuchashaszoci curred in the past'to .set up: bendingstresses urging the: guard arm of one coupler outwardlyandthus: causing: failure of the couplerthead. The improved guardarm' shape permitting the conditionshowninFig; 5 tobe; attained provides forthe distribution: of thexstressesfover greater portions ofboth couplers. lt hasbeenifoundi that couplers providedwith the improved guard'armcone tour surface will absorb approximately." three times: greater'impact forces or'about 1,360,000 pounds*without1: rupture-of the coupler head in thecontour area l8i-ofrthe' coupler.

The disadvantageous stable condition of two'couplers of i a prior'design engaging under similar conditions'isdiae grammatically illustrated in Fig. 6. The coupler shown at the left has its'knuckle in the partly closed position while the knuckle ofthe coupler on the'right'is. in thefully closed position. The nose of the partly closed knuckle engages the nose of the other knuckle in the area indicated at 51. The heel portionof the partly closed: knuckle engages the guard arm of the coupleratthe right; in an area indicated at 53. When both couplers are'in; the angular relationship depicted'in Fig. 6'the1impact' force acts along the line 36 which extends between'the' butt bearing surfaces of 'the'coupler stems. Oneline of force 52 extends perpendicularly from thecontacting surfaces at 51 and the other line of 'forcesfizextends'at right angles from the contacting surfaces at 53. These forces intersect at a point 54which lies substantiallyon .theline: 36. Line 36 passes near the pivot'pointof the partlya': closed knuckle. In view of the fact that there; isconsiderable friction between the bearing parts .of Jthepartly closed knuckle no resultant unbalanced momentexiststto: rotate the couplers from the position shown in Fig; 6' hence a stable condition exists. Thus the two opposing: couplers of a prior type move into engagement with'eaclr other without the development of aresultant force for moving the partly closed knuckle to a more closed position. The partly closed knuckle remains in a position to be wedged between thenose of the closed knuckle and l the guard arm tending to bend the guard arm outwardly and tending to shift the knuckle side ofthe couplerout wardly as a result of the wedging. action on-thenose thereof. Accordingly one of the couplers'is required to absorb the impact force in such a manner that rupturehas occurred in the arearepresented approximately by the line 57.

The removal of a relatively small portion ofmetalwithin the guard arm contour provides the'advantage of developing a resulting'force as hereinbefore described in connection with Figs. 4 and 5 to swing' the two couplers laterally as a result of an unstable condition that is developed to provide for the heel portion'of-both knuckles of opposed couplers to come into engagement with the guard arms and more. generally transversesurfacesthereona With acouplersuch" asshown -in Fig. 1' and withxtwm such couplers arriving in the"- condition; shownninuFigl 5 L 1 .5 substantially all danger of breakage or failure in the vicinity of the line 57 of Fig. 6 is eliminated for normal operation of the railway vehicles. It is to be noted that the altered guard arm contour does not change the normal operation of the coupler.

While the invention has been described with reference to a particular type of interlocking coupler it will be appreciated that the guard arm of other couplers may be similarly shaped and other modifications and changes may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

What I claim and desire to secure by Letters Patent is:

1. In a railway coupler, a coupler head having a contour thereon, a guard arm projecting forwardly beyond a rear portion of said contour and at one side of the coupler head, a concave surface forming a portion of the inner face of said guard arm generated about a vertical axis spaced laterally of the longitudinal center of the coupler head at a distance of approximately six and fifteen-sixteenth inches, said concave surface merging with a more generally straight surface in proceeding towards a nose portion of the guard arm, said concave surface joining said contour in a vertically extending ridge positioned laterally of the center line of the coupler head a distance of approximately six and fifty-seven sixty-fourth inches and forming an abutment surface laterally of said ridge generally transverse of the longitudinal axis of the coupler head.

2. In a railway coupler, a coupler head having a contour thereon, a knuckle mounted on the coupler head for swinging movements about a vertical axis and being in a closed position, a guard arm on the coupler head extending forwardly of the contour, a nose on said knuckle, a convex heel surface on said knuckle, a vertically extending ridge on said guard arm positioned forwardly of the coupling line, a concave surface forming an inner face of said guard arm forwardly of said ridge generated about a vertical axis positioned laterally of the center line of the coupler head a distance greater than the lateral displacement of said ridge from said center line, said concave surface extending to said ridge providing a forward facing shoulder adjacent said ridge substantially at right angles to said center line, the radius about which said concave surface is formed being not less than that of said convex heel surface whereby the heel of an opposed partly open knuckle engages only said forward facing shoulder in the vicinity of said ridge when the nose of the partly open knuckle is in engagement with the nose of said closed knuckle and the remainder of the convex heel of the opposed partly open knuckle cannot bear against said concave surface when the nose of the partly open knuckle is in engagement with the nose of said closed knuckle.

3. In a railway coupler, a coupler head having a contour thereon, a knuckle mounted on the coupler head for swinging movements about a vertical axis and being in a closed position, a guard arm on the coupler head extending forwardly of the contour, a nose on said knuckle, a convex heel surface on said knuckle, a vertically extending ridge on said guard arm positioned forwardly of the coupling line, a concave cylindrical surface forming an inner face of said guard arm generated about a vertical axis positioned laterally of the center line of the coupler head a distance greater than the spacing of said ridge from said center line, said concave surface extending to said ridge providing a forward facing shoulder outwardly of said ridge generally at right angles to said center line, the radius about which said concave surface is developed being approximately equal to but not less than that of the convex heel surface of the knuckle of an opposed coupler whereby the heel of the opposed knuckle in a partly open position engages only said forward facing shoulder when the nose of the partly open knuckle is in engagement with the nose of said closed knuckle with the remainder of the convex heel of the opposed partly open knuckle spaced from said concave surface when the nose of the partly open knuckle is in engagement with the nose of said closed knuckle.

4. Two railway couplers comprising, a first and a second coupler head each having a contour thereon, a knuckle mounted on each coupler head for swinging movements about a vertical axis, a nose on each knuckle, a guard arm on the second coupler head extending forwardly of the contour thereof, a convex heel surface on the knuckle carried by the first coupler head, the knuckle on the first coupler head being in a partly open position and the knuckle of the second coupler head being in a fully closed position as the two couplers move towards each other, a vertically extending ridge on the guard arm of the second coupler head positioned forwardly of the coupling line, a concave surface forming an inner face of said guard arm generated about a vertical axis positioned laterally of the center line of the second coupler head a distance greater than the lateral spacing of said ridge from said center line, said concave surface extending to said ridge providing a forward facing shoulder in the vicinity of said ridge substantially at right angles to the center line of the second coupler head, the radius about which said concave surface is developed being not less than that of said convex heel surface so that said heel engages said forward facing shoulder when the nose of the knuckle on the first coupler is in engagement with the nose on the knuckle on the second coupler head whereby the remainder of said convex heel surface cannot bear against said concave surface when the nose of the partly open knuckle is in engagement with the nose of said closed knuckle.

References Cited in the file of this patent FOREIGN PATENTS 734,454 Great Britain May 11, 1953