US3834553A

US3834553A - Rotary operated coupler locklift mechanism

Info

Publication number: US3834553A
Application number: US00395958A
Authority: US
Inventors: Penti K De
Original assignee: Midland Ross Corp
Current assignee: Midland Ross Corp; National Casting Inc
Priority date: 1973-09-10
Filing date: 1973-09-10
Publication date: 1974-09-10
Anticipated expiration: 1991-09-10
Also published as: BR7407412D0; AU7240674A; GB1437309A; CA1011292A; ZA745273B; AR201965A1

Abstract

A bottom rotary operated railway car coupler for actuation by a bail type uncoupling rod mechanism has a rotor lever with an operating arm portion engageable by the bail of the uncoupling mechanism and contoured to not only clear the car underframe without striking it when the coupler is buffed back to its fully buffed position but to also provide sufficient clearance with the underside of the coupler head to enable rotation of the rotor lever to its full knuckle opened position in all positions of the coupler in service.

Description

United States Patent [191 DePenti [4 Sept. 10, 1974 ROTARY OPERATED COUPLER LOCKLIFT MECHANISM [75] Inventor: Kenneth L. DePenti, Mayfield Heights, Ohio [73] Assignee: Midland-Ross Corporation,

Cleveland, Ohio [22] Filed: Sept. 10, 1973 [21] Appl. No.: 395,958

[52] US. Cl 213/166, 213/146, 213/211 51 Int. Cl. B6lg 3/08 53 Field of Search 213/133,219, 166-170, 213/146, 211

[56] References Cited UNITED STATES PATENTS 3,572,518 3/1971 Wisler 213/166 5/1971 DePenti 213/166 8/1973 Adler ..2l3/l66 Primary ExaminerM. Henson Wood, Jr. Assistant ExaminerGene A. Church Attorney, Agent, or Firm-Henry Kozak [5 7] ABSTRACT A bottom rotary operated railway car coupler for actuation by a bail type uncoupling rod mechanism has a rotor lever with an operating arm portion engageable by the bail of the uncoupling mechanism and contoured to not only clear the car underframe without striking it when the coupler is buffed back to its fully buffed position but to also provide sufficient clearance with the underside of the coupler head to enable rotation of the rotor lever to its full knuckle opened position in all positions of the coupler in service.

8 Claims, 5 Drawing Figures ROTARY OPERATED COUPLER LOCKLIFT MECHANISM BACKGROUND OF THE INVENTION This invention relates in general to bottom rotary operated railway car couplers and, more particularly, to a rotary locklift lever therefor adapted for actuation by a bail type uncoupling rod mechanism.

Conventional rotary dump railway cars which permit the dumping of the Iading of each car by the controlled overturning thereof in a rotary dumping apparatus while the car is still connected in a train are generally equipped with one or more rotary type couplers which are adapted to rotate 180 relative to the car and are uncoupled by an uncoupling mechanism having no physical connection between that portion thereof mounted on the car body and that portion mounted in operative position on the coupler head. Such uncoupling mechanisms conventionally consist of a bail type uncoupling rod assembly which is independently mounted on the end sill of the car for operation from either or both sides thereof and is engageable with an operating arm portion of a rotor lever member of the coupler unlocking mechanism. Actuation of the rotor lever member on the coupler by the bail of the uncoupling rod assembly lifts and unlocks the coupler lock from the coupler knuckle and swings the knuckle to its open position.

Prior rotary uncoupling mechanisms of the above described bai] operated type such as disclosed, for example, in U.S. Pat. Nos. 3,572,518 Wisler and 3,580,400 DePenti, have not proven entirely satisfactory in operation for one reason or another. In some cases the coupler knuckle opening operation not only has been difficult to perform but in certain angled positions of the coupler the coupler could only be lock-set so that a complete opening of the knuckle on actuation by the bail member of the uncoupling rod assembly was impossible. In other instances where the rotary lever member could strike against the striker casting under full bufi, the impact could possibly overcome the coupler lock anti-creep means and place the lock in its lock-set position such as to cause a train separation.

SUMMARY OF THE INVENTION It is an object of the invention therefore to provide a bottom rotary operated car coupler which is adapted for actuation by bail type uncoupling rod mechanism and which will operate easily and be capable of effecting a complete opening of the coupler knuckle in all possible positions of the coupler in service.

Another object of the invention is to provide a bottom rotary operated car coupler as described above and having a rotor lever member the operating arm of which will not strike against the striker casting of the associated car under full buff condition in all possible positions of the coupler in service.

Still another object of the invention is to provide a bottom rotary operated car coupler as described above and which not only is capable of effecting a complete opening of the coupler knuckle in all possible angled positions thereof but the rotor lever operating arm of which at the same time will not strike against the striker casting of the associated car under full buff condition in all possible positions of the coupler in-service.

A further object of the invention is to provide a novel form of rotor lever for a bottom rotary operated car coupler.

Briefly stated, in accordance with one aspect of the invention, the rotor lever member of a bottom rotary operated coupler is provided with an operating arm portion which, in the normal lowered or inoperative rest position of the rotor lever member, extends downwardly from the hub of the rotor lever and has the inner end portion thereof, which in such lowered position is coextensive with the car underframe, offset forwardly of the coupler a sufficient distance to clear the car underframe in all positions of the coupler in service, without striking it or at most just touching it when the coupler is under full buff, thereby avoiding the possibility of the coupler anti-creep means being overcome at such time and the coupler being placed in lock-set condition such as to cause a train separation.

In accordance with a further aspect of the invention, the outer end portion of the rotor lever operating arm is at the same time offset rearwardly of the coupler relative to its inner end portion to thereby provide clearance to enable rotation of the rotor lever to its full knuckle opened position, in all angled positions of the coupler in service, without the rotor lever outer end striking against, or at most just touching, the underside of the coupler head.

Further objects and advantages of the invention will appear from the following detailed description of a species thereof and from the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top plan view of the end of a freight car showing a bail type operating rod assembly, in its normal rest position, for a bottom rotary operated car coupler according to the invention;

FIG. 2 is a side elevation of the car coupler comprising the invention and the associated uncoupling rod mechanism therefor taken on the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary vertical section of the coupler taken on the line 3-3 of FIG. 2 and showing the locklift mechanism thereof comprising the invention in its normal rest position;

FIG. 4 is a fragmentary sectional view taken on the line 44 of FIG. 3 with the coupler shown in its full buff position and the coupler locklift linkage shown in its normal rest position, and

FIG. 5 is a side elevation of the coupler rotor lever member comprising the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, FIG. 1 illustrates a rotary dump car 10 having a bail type uncoupling rod assembly or mechanism 12 to actuate a bottom rotary open ated car coupler l4 constructed according to the invention and mounted on the car for rotational movement relative thereto about that longitudinal axis of the car which coincides with the longitudinal axis of the coupler when in its normal centered position on the car. The uncoupling rod assembly 12 shown comprises a generally U-shaped bail member 16 formed of suitable steel rod and comprised of a coupler engaging central bight portion 18 extending between and interconnecting oposite upwardly extending side arm portions 20 which terminate in outturned aligned bearing end portions 22 that extend parallel to but are offset from the central bight portion 18. The bearing end portions 22 are mounted in brackets 24 for vertical pivotal movement of the bail member 16 in a vertical plane extending longitudinally of the car 10. The brackets 24 are secured to support arms 26 mounted on the center sill 28 of the car underframe.

The bail member 16 is supported on the brackets 24 in a position with its bight portion 18 extending trans versely of the car and, in the normal rest position of the uncoupling rod assembly, passing transversely beneath the shank portion 30 of the coupler 14 which is disposed longitudinally of the center sill 28 of the car and extends into the striker casting 32 mounted on the end of the center sill. A bail extension plate 34 (FIG. 2) is secured, as by weld metal 36, to the transversely extending bight portion 18 of the bail member 16 so as to extend therefrom in a direction approximately normal to the side arm portions of the bail member 16 and toward the head portion 38 of the coupler 14. Upon actuation of the bail member 16 to swing it forwardly toward the coupler 14, the plate 34 engages the operating arm 40 of a rotor lever 42 of the coupler unlocking mechanism to swing the arm 40 in a clockwise direction, as viewed in FIG. 2, and thus rotate the rotor lever 42 so as to actuate the coupler locklift linkage or unlocking mechanism 14.

The bail operating mechanism is generally shown at 46 and comprises an operating rod 48 formed of suitable steel rod and extending more or less transversely of the car 10. The operating rod 48 is rotatably supported adjacent its outboard end for rotation about its axis in a U-shaped bearing portion 50 of a support bearing bracket 52 secured to the corner cap 54 of the car underframe. Rod 48 is held in place within the U- shaped bearing portion 50 of bracket 52 by cotter pin 56. The outer end of the operating rod is bent downwardly to form a handle 58 for manual actuation of the bail operating mechanism 46. The rod 48 terminates at its inner end in a hook end 60 which is hooked into an eye portion 62 formed at the outer end of the adjacent outturned bearing end portion 22 of the bail member 16. Upward swing movement of the handle 58 away from the end of the car 10 rotates the operating rod 48 which, in turn, through the hook 60 and eye 62 connection, effects rotation of the bail member 16 in its bearing brackets 24, causing its bight portion 18 to swing upwardly and forwardly in an arc-like path, as indicated by the dot-dash line 64 in FIG. 2, so that the plate 34 thereon engages the operating arm 40 of and rotates the rotor lever 42 of the coupler unlocking mechanism.

Secured to one of the side arms 20 of bail member 16 is a plate bracket 66 to which a tension coil spring 68 is attached at one end. The spring 68 is connected at its other end to a bracket 70 mounted on the center sill 28. This spring loading of the bail member 16 is provided to not'only assure the automatic return thereof to its normal rest position, shown in solidlines in FIG. 2, after the operation of the uncoupling rod assembly 12 to effect the opening of the coupler knuckle 72 or to place the coupler in its lock-set position has been completed, but to also assure that the bail member remains in its normal rest position when the car is turned over during rotary dumping operations. It will be seen from FIG. 2 that the operating arm 40 of the rotor lever member 42 when in its normal rest position is entirely clear of the bail member 16 so that there is no interference between these parts upon rotation of the coupler 14 about its horizontal longitudinal axis during rotary dumping of the car.

The particular coupler 14 illustrated is that commercially known as an A.A.R. (Association of American Railroads) Type F Interlocking coupler comprising the head portion 38 and the shank portion 30 extending therefrom. The coupler is mounted on the end of the car 10 with its shank portion 30 disposed longitudinally of and extending into the car center sill 28 and with its head portion 38 located outwardly beyond the end of the center sill. The coupler head 38 is provided on its upper side with the customary horn portion 39 having a rearwardly facing vertical buffing surface 39 which defines the coupler horn line H (FIG. 2) and abuts against the striker casting 32 of the car underframe to limit the inward buffing movement of the coupler and determine its full buff position. The coupler also has a knuckle 72 swingably mounted on the coupler head portion 38 by a pivot pin 74. At its underside, the coupler head 38 is provided with a pair of downwardly extending

vertical walls

76 and 78 depending from its bottom wall and spaced apart laterally of the coupler to form therebetween a passageway or chamber 80 (FIGS. 3 and 4) for the accommodation therein of the leg 82 of a conventional coupler lock 84 along with the locklift assembly linkage 44, the passageway 80 communicating with the lock receiving cavity or hole 86 in the bottom wall 88 of the coupler head 38. The locklift assembly linkage 44 comprises the usual toggle 90 pivotally connected at its lower end by rivet 92 to the outer end of the locklift lever arm portion 94 of the rotor lever 42. The upper end of the toggle 90 is pivotally connected to the lower end of the lock leg 82 by means of a trunnion 96 on the toggle which is entered into and rides in an upwardly and rearwardly inclined slot 98 in the lower end of the lock leg 82. The rotor lever member 42 is rotatably mounted on the coupler head 38 on a pivot pin 100 for rotation in a vertical plane parallel to the longitudinal center line of the coupler and within the passageway 80 between the spaced

side walls

76,78. The pivot pin 100 spans the passageway 80 and is suitably fastened in place to the

side walls

76,78 as by a cotter pin 101. Clockwise rotation of the rotor lever 42 about its pivot pin 100, as viewed in FIG. 4, operates to swing the rotor lever locklift arm 94 upwardly, thereby forcing toggle 90 upwardly to first disengage it from the conventional anti-creep shoulder on the tail of the knuckle 72 and then raise the lock 84 to cause it to pivot the usual knuckle thrower (not shown) located within the hollow interior of the coupler head 38 so as to effect the opening of the knuckle 72, all in the well known manner.

To assure proper and facile operation of the coupler l4 and its uncoupling mechanism 12 under all conditions normally encountered in service, and particularly the full opening of the coupler knuckle 72, the rotor lever member 42 is provided, in accordance with he invention, with an operating arm 40 of a particular contour or configuration, as shown in FIGS. 2, 4 and S. The operating arm 40 and locklift lever arm 94 of the rotor lever member 42 extend transversely to one another from the hub portion 102 thereof which has a slotshaped opening or aperture 104 for the reception of the pivot pin 100 on which the rotor lever pivots on the coupler head 38 about the pivot point P. In the normal rest position of the rotor lever member 42, as shown in FIGS. 2 and 4, the operating arm 40 thereof extends vertically downward from the hub portion 102.

For the purposes of the invention, that inner end portion 106 of the total longitudinal'extent of the rearwardly facing operating surface 108 of the operating arm 40 against which the plate 34 on the bail member 16 strikes and along which it rides during the actuation of the uncoupling mechanism 12, and which inner end portion 106, in the normal rest position of the rotor lever member, is coextensive with and opposed to the front face 110 of the striker casting 32, is located a sufficient distance forwardly of the coupler relative to its horn line H to clear, i.e., not strike against, or at most just touch, the striker casting front face 1 during the full buff of the coupler. This clearance is indicated at 112 in FIG. 4, which shows the coupler 14 in its full buff position. To this end, the inner end portion 106 of the operating surface 108 of operating arm 40 is located, in the case of the particular rotor 42 shown when in its normal rest or inoperative position on a standard Type F coupler 14, in a vertical plane disposed normal to the longitudinal center line of the car 10 and spaced a distance of approximately 1 15/ 16 inches rearwardly of the pivot point P of the rotor 42, as shown in FIG. 5. This particular spacing of the operating surface portion 106 of arm 40 from the pivot point P of the rotor 42 is effective to provide the desired clearance 112 from the striker casting front face 110 in the case of standard A.A.R. Type F coupler such as illustrated. This clearance is present not only when the coupler is in its normal elevational position on the car but also as well when the coupler is in its limiting downward angled position thereon such as sometimes occurs when the vertical pivot points of F type couplers on coupled cars are at different heights, as when as empty car is coupled to a heavily loaded car or when the coupled cars are moved over a vertical curved track. The clearance thus provided in accordance with the invention between the operating arm '40 of rotor 42 and the striker casting face 110 during full buff of the coupler 14 therefore avoids the dangerous possibility of the rotor 42 bouncing back off the striker casting, were it to impact thereagainst during severe buffing operations, and so actuating the coupler locklift linkage 44 to disengage the anti-creep means of the coupler and place the lock 84 in its lockset position. This then would result in opening of the coupler knuckle 72 and separation of the train upon subsequent application of a pulling force to the coupler.

Further in accordance with the invention and as shown in FIGS. 2, 4 and 5, the outer end portion 114 of the rotor operating arm 40 is offset, relative to the inner end portion 106 of its operating surface 108, in a direction away from the locklift arm 94'of the rotor 42 and rearwardly of the coupler 14 in the normal rest position of the rotor. For thepurposes of the invention, the distance the outer end 114 of arm 40 is thus offset is sufficient to permit the rotor 42 to be rotated and the lock 84 to be lifted the required amount, in all possible coupler positions encountered in service, to effect the full opening of the coupler knuckle 72 before the forwardly facing surface 116 of the outer end 114 of the rotor operating arm 40 strikes against or at most just touches the coupler safety support shelf 118 (FIG. 4) immediately forward of the lock passageway 80 in the coupler. head 38 to limit further rotation of the rotor 42. This limiting rotative position of the rotor 42 and its operating arm 40 is shown in dot-dash lines in FIGS. 2 and 4. In the particular case shown of a rotor 42 rotatably mounted on a standard Type F coupler 14 for rotation about the conventional rotor pivot point P, the flat front face 116 of the offset outer end portion 114 of the rotor operating arm 40 has its outermost end point 120 located, when the rotor is in its normal rest position, a distance of at least around I l5/l6 inches rearwardly of the coupler from the vertical plane or center line A normal to the longitudinal axis of the car 10 that passes through the pivot point P of the rotor and around 7 13/16 inches downwardly from such pivot point P. From this outermost end point 120, the front face 116 of the outer end portion 114 of arm 40 slopes upwardly and rearwardly, away from the plane A and from the other arm 94 at a slight angle of at least 5 or thereabouts so as to thereby extend approximately parallel to that portion of the horizontal underside 122 of the coupler shelf 118 with which it is coextensive in the limiting upward pivoted position of the rotor 42, as shown in FIG. 4. The offsetting of the forwardly facing outer end surface 116 of the rotor operating arm 40 in the above described manner thus assures against any interference, in any position of the coupler on the car, between the underside 122 of the coupler shelf 118 and the rotor operating arm 40, during the rotation of the rotor 42 to effect the opening of the coupler knuckle 72, such as would prevent rotation of the rotor through the required arc (85 in the particular case illustrated) to effect the full opening of the knuckle.

As shown in FIGS. 4 and 5, the inner end operating surface portion 106 of the rotor operating arm 40 is joined to the outer end operating surface portion 124 thereof by a reverse curved connecting surface section 126 of comparatively large radius curvature, over and past which curved section 126 the plate 34 on the bail member 16 will ride freely and smoothly during the operation of the uncoupling mechanism. Smooth opera tion of the uncoupling mechanism 12 is thus assured at all times. Also, as will be evident from FIG. 4, the reverse curved connecting surface section 126 of the rotor arm operating surface 108 is suitably contoured, as in the particular manner shown in FIG. 5, so as to clear and not strike against the rounded bottom end corner 128 of the striker casting 32 during the buffing of the coupler 14 back to its full buff position such as might likewise cause, as described hereinabove, the rotor 42 to rebound and lift the coupler lock 84 to its lockset position with consequent possible train separation. To this end, the concave curved inward portion 130 of the reverse curved connecting surface section 126 is curved on a radius of around 1 inch centered so that the straight inner end portion 106 of the operating surface 108 tangentially joins with this concave curved surface portion 130. In the same manner, the forwardly facing outer end surface 116 of the rotor operating arm 40 is tangentially joined with a concave curved inward connecting surface section 132 curved on'a radius of around 1 H16 inches centered at a point located around 6 9/16 inches vertically down from the horizontal center line B of the pivot point P of the rotor.

It should be understood that the application of the invention, involving the use of bail type uncoupling rod mechanism 12, to an A.A.R. standard F type coupler such as shown requires a modification in the contour of the bottom edges of the lock

chamber side walls

76,78

of the coupler head 38 in order to provide the necessary clearance for the horizontal bight portion 18 of the bail member 16 during its upward swing movement by the bail operating mechanism 46 to fully open the coupler knuckle 72. To this end, the portions of the lock

chamber side walls

76,78 of such standard F type couplers which project downwardly from the coupler head 38 between the front or buffing wall 134 thereof and the pivot pin 100 for the rotor 42 must be made of shorter vertical extent or cut back from their conventional contour so as to locate their bottom edges at the necessary higher elevation, such as shown at 136 in FIG. 4, to provide the aforesaid required clearance for the bight portion 18 of the bail member 16 during its operative swing movement and not obstruct or interfere therewith in any way in all possible positions of the coupler on the car in service.

What is claimed is:

1. A bottom operating railway car coupler for mounting on a car underframe for rotation about the longitu' dinal axis of the coupler and for movement longitudinally of the car to a buffed rearward position thereon, said coupler comprising a head provided with a horn portion having a vertical buffing face defining a vertical horn line and engageable with the said car underframe to limit inward buff movement and determine the full buff position of the coupler, a knuckle pivoted on said coupler head, and knuckle unlocking and opening means on said coupler comprising a rotor mounted on said coupler head for rotational movement in a vertical plane from a lowered rest position to a raised operative position to open the said knuckle, said rotor having a hub portion and an operating arm portion extending downwardly therefrom in the said rest position of the rotor and into the path of swing movement of a bail member of an associated uncoupling rod assembly mounted on the car, the outer end portion of said rotor operating arm being offset rearwardly of the coupler relative to the inner end portion thereof a sufficient distance to enable rotation of said rotor to its full knuckle opened position without the said outer end portion striking against the underside of the coupler head.

2. A bottom operating railway car coupler as specified in claim 1 wherein the inner end portion of the length of the rearwardly facing operating surface of said rotor arm engageable by said bail member and co extensive with the said car underframe in the said rest position of the rotor is located forwardly of the coupler a sufficient distance to clear the said car underframe without striking it when the rotor is buffed to its said full buff position.

3. A bottom operated railway car coupler as specified in claim 2 wherein the said inner end portion of the rearwardly facing operating surface of said rotor comprises a straight inner section extending approximately vertically in the said rest position of the rotor and spaced a distance of approximately 1 l/l6 inches rearwardly of the coupler from the pivot point of the rotor thereon, said straight inner section of the said a radius of at least approximately I inch centered at a point located approximately 5 5/l6 inches from the horizontal center line through the pivot point of the rotor.

4. A bottom operated railway car coupler as specified in claim 2 wherein the forwardly facing surface of the said offset outer end portion of said rotor operating arm extends, in the said rest position of the rotor, upwardly and rearwardly of the coupler at a slight angle to the vertical from a point located at least approximately 1 15/ l 6 inches rearwardly of the pivot point of the rotor on the coupler.

5. A bottom operated railway car coupler as specified in claim 3 wherein the forwardly facing surface of the said offset outer end portion of said rotor operating arm extends, in the said rest position of the rotor, upwardly and rearwardly of the coupler at an angle of around 5 to the vertical from a point located at least approximately 1 15/16 inches rearwardly of the pivot point of the rotor on the coupler.

6. A rotor lever for a bottom operated car coupler comprising a hub portion having a pivot pin opening therethrough for pivotal mounting of the rotor lever on a horizontal pivot pin on the coupler for rotation about a hub pivot point defined by the intersection of horizontal and vertical hub center lines, and an operating arm and a locklift arm extending from said hub portion transversely to one another, said locklift arm having a pivot pin opening centered at the intersection of horizontal and vertical offset center lines respectively offset from the said horizontal and vertical hub center lines, said operating arm extending from said hub at the same side of the said hub horizontal center line as the said locklift arm pivot pin opening and having an operating surface facing away from and located on the opposite side of said vertical hub center line from said locklift arm, the inner end portion of said operating surface extending from said hub in a direction generally longitudinally of and ofiset from the said vertical hub center line a sufficient distance to clear the associated striker casting of the car on which the coupler is mounted, when the coupler is in its full buff position thereon, said operating arm having an offset outer end portion offset to the opposite side thereof from said vertical hub center line, the front surface of said offset outer end portion facing the said vertical hub center line being offset therefrom a sufficient distance to clear the underside of the said coupler when the rotor is rotated to its full knuckle opened position on the coupler,

7. A rotor lever as specified in claim 6 wherein the said inner end operating surface portion tangentially joins at its outer end with a slightly concavely curved connecting surface section, and the said front surface of the said offset outer end portion of the operating arm said front surface of the said offset outer end portion of the operating arm extends inwardly thereof at a rotor operating surface tangentially joining outwardly 0 slight angle away from the said vertical hub center line.

with a concavely curved connecting section curved on

Claims

1. A bottom operating railway car coupler for mounting on a car underframe for rotation about the longitudinal axis of the coupler and for movement longitudinally of the car to a buffed rearward position thereon, said coupler comprising a head provided with a horn portion having a vertical buffing face defining a vertical horn line and engageable with the said car underframe to limit inward buff movement and determine the full buff position of the coupler, a knuckle pivoted on said coupler head, and knuckle unlocking and opening means on said coupler comprising a rotor mounted on said coupler head for rotational movement in a vertical plane from a lowered rest position to a raised operative position to open the said knuckle, said rotor having a hub portion and an operating arm portion extending downwardly therefrom in the said rest position of the rotor and into the path of swing movement of a bail member of an associated uncoupling rod assembly mounted on the car, the outer end portion of said rotor operating arm being offset rearwardly of the coupler relative to the inner end portion thereof a sufficient distance to enable rotation of said rotor to its full knuckle opened position without the said outer end portion striking against the underside of The coupler head.

2. A bottom operating railway car coupler as specified in claim 1 wherein the inner end portion of the length of the rearwardly facing operating surface of said rotor arm engageable by said bail member and coextensive with the said car underframe in the said rest position of the rotor is located forwardly of the coupler a sufficient distance to clear the said car underframe without striking it when the rotor is buffed to its said full buff position.

3. A bottom operated railway car coupler as specified in claim 2 wherein the said inner end portion of the rearwardly facing operating surface of said rotor comprises a straight inner section extending approximately vertically in the said rest position of the rotor and spaced a distance of approximately 1 15/16 inches rearwardly of the coupler from the pivot point of the rotor thereon, said straight inner section of the said rotor operating surface tangentially joining outwardly with a concavely curved connecting section curved on a radius of at least approximately 1 inch centered at a point located approximately 5 5/16 inches from the horizontal center line through the pivot point of the rotor.

4. A bottom operated railway car coupler as specified in claim 2 wherein the forwardly facing surface of the said offset outer end portion of said rotor operating arm extends, in the said rest position of the rotor, upwardly and rearwardly of the coupler at a slight angle to the vertical from a point located at least approximately 1 15/16 inches rearwardly of the pivot point of the rotor on the coupler.

5. A bottom operated railway car coupler as specified in claim 3 wherein the forwardly facing surface of the said offset outer end portion of said rotor operating arm extends, in the said rest position of the rotor, upwardly and rearwardly of the coupler at an angle of around 5* to the vertical from a point located at least approximately 1 15/16 inches rearwardly of the pivot point of the rotor on the coupler.

6. A rotor lever for a bottom operated car coupler comprising a hub portion having a pivot pin opening therethrough for pivotal mounting of the rotor lever on a horizontal pivot pin on the coupler for rotation about a hub pivot point defined by the intersection of horizontal and vertical hub center lines, and an operating arm and a locklift arm extending from said hub portion transversely to one another, said locklift arm having a pivot pin opening centered at the intersection of horizontal and vertical offset center lines respectively offset from the said horizontal and vertical hub center lines, said operating arm extending from said hub at the same side of the said hub horizontal center line as the said locklift arm pivot pin opening and having an operating surface facing away from and located on the opposite side of said vertical hub center line from said locklift arm, the inner end portion of said operating surface extending from said hub in a direction generally longitudinally of and offset from the said vertical hub center line a sufficient distance to clear the associated striker casting of the car on which the coupler is mounted, when the coupler is in its full buff position thereon, said operating arm having an offset outer end portion offset to the opposite side thereof from said vertical hub center line, the front surface of said offset outer end portion facing the said vertical hub center line being offset therefrom a sufficient distance to clear the underside of the said coupler when the rotor is rotated to its full knuckle opened position on the coupler.

7. A rotor lever as specified in claim 6 wherein the said inner end operating surface portion tangentially joins at its outer end with a slightly concavely curved connecting surface section, and the said front surface of the said offset outer end portion of the operating arm tangentially joins at its inner end with a slightly concavely curved connecting surface section.

8. A rotor lever as specified in Claim 6 wherein the said front surface of the said offset outer end portion of the operating arm extends inwardly thereof at a slight angle away from the said vertical hub center line.