US3391800A - Transition type couplers for railway vehicles - Google Patents

Description

July 1968 OM PRAKASH TANTIA 3,

TRANSITION TYPE COUPLERS FOR RAILWAY VEHICLES Filed March 1, 1966 2 Sheets-Sheet 1 Inventor 0M PHAKASH TANTIA A Home y y 9, 1968 OM PRAKASH TANTIA 3,39

TRANSITION TYPE COUPLERS FOR RAILWAY VEHICLES Filed March 1, 1966 2 Sheets-Sheet 2 Inventor 0M PRAKASH TANTIA A Home y United States Patent 3,391,800 TRANSITION TYPE COUPLERS FGR RAILWAY VEHICLES Om Prakash T antia, 4 Sarat Chatterjee Ave., Calcutta 29, India Filed Mar. 1, 1966, Ser. No. 530,992 13 Claims. (Cl. 213-112) ABSTRACT OF THE DISCLOSURE Transition type couplers using a clevis and screw coupler wherein the clevis has formed near the free end of the clevis shank a ledge or ridge which extends around the shank substantially along the bearing surface of the bow shackle with the said shank, and has a shoulder formed on at the opposite end of the shank and part of the bearing surface on the shank between the said shoulder and said ledge is recessed.

Prior art Certain railway systems have still in use draw bar hook type of couplings with side buffers. With the advancement of railroad engineering, it has been found that automatic centre buffer couplers are more satisfactory for purposes of coupling two railway vehicles. Due to increase in horsepower of locomotives, it has also become possible to haul larger trains which necessitates greater draw bar pull to be exerted on the railway vehicle couplings.

Transition type couplers are used where the existing rail vehicles having the draw bar hooks are to be coupled to newly introduced centre buffer couplers. The object of the transition coupler therefore is to permit vehicles with centre bufier couplers to be coupled to each other and also to permit coupling of the same with vehicles having draw bar hooks.

In the known centre buffer couplers, there is provided a clevis pivotally mounted in a jaw on the said coupler and this coupler is rendered transition type by the provision of a screw coupling. The term screw coupling is used to designate a coupling comprising a bow shackle which engages the clevis and a second shackle which engages the draw bar hook, both shackles being connected by a threaded spindle. The clevis provides the required bridge at the knuckle head of the centre buffer coupler and holds the bow shackle in a centrally located position whereby the draw bar forces pass through the centre line of the said coupler. In the locked position, a profile on the clevis mates with a depression on the knuckle head. This ensures that once the clevis and the knuckle head are locked in position, there is practically no relative vertical movement between the two.

The difiiculty arises when due to improper locking of the knuckle head with the clevis, the knuckle head which is pivotally mounted opens out and the bow shackle slips off the clevis. The second shackle being engaged by the draw hook can easily slip off resulting in loss of the screw coupling. To prevent the bow shackle from slipping off, lugs were welded on the clevis after the bow shackle was slipped on. In the clevis with these lugs the bow shackle could not slip ofiF. However, it has been found that in the yards, the line staff do not lock the clevis properly but leave the clevis loose in relation to the knuckle head. They only couple the screw coupling to the draw hook of the other vehicle. Under these conditions, when the train is pulled, the forces exerted by the shackle against the welded lugs tend to damage these lugs which lugs in many cases give way, thus causing the screw coupling to slip ofl.

3,391,800 Patented July 9, 1968 Objects of the invention The principal object of this invention is to so modify the clevis that the aforesaid disadvantages are eliminated. It is another object of this invention to so modify the clevis that without impairing its strength, its weight is reduced.

The invention According to this invention in a transition type coupler employing a clevis and screw coupler, near the free end of the clevis shank is formed a ledge or ridge which extends around the shank substantially along the bearing surface of the bow shackle with the said shank, while at the opposite end of the said shank is formed a shoulder and a part of the bearing surface on the shank between the said shoulder and said ledge is recessed.

According to another feature of this invention the ridge terminates at each of its ends in a nose and the noses thus formed provide in conjuction with the said shoulder, diagonal constrictions for the bow shackle in engagement with the clevis shank, in a position, when the clevis is not in engagement with the knuckle of the coupler and the said clevis is pulled with the shackle,

Further the inner face of the ledge is inclined such that when the knuckle is engaging the clevis, the shackle has the necessary free play in the said recess of the shank, but when the knuckle is not engaging the clevis, and is pulled by the shackle, then by virtue of the incline in the ridge, the noses of the said ridge come into engagement with the bow shackle and in cooperation with the shoulder prevent the clevis from adopting a position substantially different from that when the said clevis was held by the said knuckle.

According to another embodiment the head at the end of the clevis shank is provided on its cooperating surface with a ridge or the like having a contour which cooperates with the knuckle and pushes or kicks it into locked position so that by rotating the clevis, locking is not only facilitated but automatically effected and the bow shackle can adopt a position suitable for engagement with the draw hook when the clevis is locked in position. The advantage of this modification is that when the clevis is rotated it must get locked before the bow shackle is ready for engagement with the draw bar hook.

In order to facilitate the rotation of the clevis a vertical rod is secured thereto which helps in the rotational movement of the clevis when the bow shackle is in suspended position.

Instead of having a ridge for kicking the knuckle, it is also possible to so shape the contour of the head of the clevis that the entire head acts to kick or force the knuckle into locking position.

According to a further embodiment, the bearing surface of the shank of the clevis is so shaped that it holds the bow shackle to constrict its angular movement, whereby the bow shackle is prevented from being free to adopt any other position which is normal to the clevis shank. For this purpose it is preferred to provide a shoulder on the clevis corresponding to the shoulder at the end of the clevis shank to bear on either side of the bow shackle, when the bow shackle is engaged by the clevis.

According to a further embodiment a projection is provided on the front portion of the clevis shank, the function of which is to prevent the screw coupling from being hooked on to the draw hook when the clevis is in the fully opened or idle position by either the screw coupling being lifted in a clockwise direction in this position or by rotating the same in reverse direction over about 270.

According to a further feature, the ridge which extends .all around or substantially encircles the clevis has been modified. At the nose the said ridge has been extended so that the nose position extends more below the clevis shank than the shoulder. In other words the outer end of the nose portion is made father away from the centre line of the clevis shank than the shoulder portion.

Describin gthe funcion of the above embodiment when the clevis is brought into the use and is about parallel with the track, the screw coupling is prevented from be ing lifted for coupling on to the draw hook and this is done by increasing the height of the ridge which in this position is disposed at the lower side of the clevis shank.

Other features of the invention will be clear from the drawings and the description therefor.

The invention will now be more fully described with reference to the accompanying drawings in which:

FIG. 1 is a side view of one clevis embodiment of the invention.

FIG. 2 is a cross-section of FIG. 1 taken along the line A'A'.

FIG. 3 is a perspective view of the clevis of FIG. 1.

FIG. 4 is a plan view of a transition coupler of the invention with the clevis of FIG. 1.

Referring to the drawings A shows the shank of the clevis, B its endwhich is to be pivoted to the jaw of the centre buffer coupler C by a pin D passing through the pin hole E.

According to this invention, near the free end of the clevis shank is formed a ridge R which extends around the shank A substantially along the bearing surface defined by the contact of the bow shackle F while in engagement with the said shank. At the end of the shank opposite the ridge R is formed a shoulder S such that the bearing surface between the said shoulder and said ridge is recessed as more clearly seen by reference to FIG. 1 of the drawings and marked T. This recessed portion as will be seen from FIG. 1 is only in the upper bearing surface defined by the contact of the bow shackle with the shank. The section of the shank is so made that the loop of the bow shackle is generally bearing against this recessed surface.

The ridge may extend, all around the shank of the clevis but at any rate it must extend to substantially encircle the clevis, whereby at each end where the ridge terminates a nose N is formed. This nose functions in coopration with the shoulder S and it provides diagonal constrictions for the bow shackle. This will be apparent from FIG. 1 in which the position of the bow shackle while engaging the clevis shank is illustrated. This position shown in dotted lines is assumed by the bow shackle when the clevis is not in engagement with the knuckle of the coupler and the clevis is pulled with the shackle.

The ridge may conveniently extend right along the girth of the shank.

According to another feature the inner face R of the ridge is inclined such that when the knuckle is engaging the clevis, the shackle has the necessary play along the recessed portion of the shank, but when the knuckle is not engaging the clevis and is pulled by the shackle then by virtue of the inclined face of the ridge the two noses M of the said ridge comes into immediate engagement with the arms of the bow shackle and in cooperation with the shoulder S prevent the clevis from adopting a position different from that when the clevis was held by the knuckle.

According to another feature of this invention, the free end of the shank A has a female contour marked U which is complementary to a male contour V on the knuckle.

According to another feature an are shaped lug L is provided on the clevis around the pin hole E to engage a female depression in the coupler head, said lug having an arc subtending an angle of over 120 whereby when the bow shackle is to be initially slipped over the clevis theclevis is turned through about 90 and after the shackle rests in position against the ridge, the said clevis is turned back in a position where the lug engages the depression in the coupler.

From FIG. 4 it will be seen that the clevis is engaged by a pin between the jaws of the centre buffer coupler marked P and in the working position the said clevis is held and locked by the knuckle head'K, the bow shackle engaging the clevis and the second shackle engaging the draw bar hook W of a vehicle not having a transition coupling.

In the improved design the dimensions of the pin and of the clevis in relation to the shackle are such that the shackle can he slipped on from the said end. The arc shaped lug also does not prevent the shackle from being slipped on. The clevis can then be assembled into the existing coupler and the pin pushed through. Due to the provision of the ridge the shackle is prevent from slipping off. In the event of the lock between the knuckle and the clevis opening out, the shackle of the screw coupling resting against the noses and the shoulder when pulled will cause sideways forces on the ridge R which will prevent the clevis from moving very much out of its alignment which would otherwise occur by the opening out of the knuckle. Thus, it will be seen that by the provision of this ridge R not only has the slipping off of the shackle been prevented but also the misalignment of the shackle and its displacement from the central position when draw forces are exerted has also been minimised and thus the traction forces continue to act almost centrally.

Further improvement is that the female profile now provided at the end of the clevis mates exactly with the male profile of the knuckle. The advantage gained by this is derived from the fact that this end of the clevis having already been made dimensionally large there is mating across considerable lengths of exact profiles between the clevis with its counterpart on the knuckle.

A further improvement found in the clevis according to this invention is that the section at face X is kept to a minimum as compared to the original clevis, thereby reducing considerably the weight of the casting. In so doing, the recessed portion not only helps to reduce the size and the weight of the clevis but also permits the screw coupling to be shortened :by an equivalent length as compared to the existing screw coupling. Here again the reduction in weight of the screw coupling is also caused.

The total minimum angle of the arc shaped lug is so devised that even if the lock of the knucklehead with the clevis opens out and the shackle displaces the clevis to the maximum extent possible, a considerable portion of the arc of the male lugs continue to mate with its counterpart in the couplerhead casting. This ensures that even in the open position of the knucklehead, the pin of the clevis is not unduly strained since the mating lugs continue to provide sufficient support to the clevis preventing angular displacement in the plane of the vertical axis of the pin.

I claim:

1. In and for transition type coupler employing .a clevis and screw coupler, a clevis characterized by that near the free end of the clevis shank is formed a ledge or ridge which extends around the shank substantially along the bearing surface of the bow shackle with the said shank, while at the opposite end of the said shank is formed a shoulder and that a part of the bearing surface on the shank between the said shoulder and said ledge is recessed, said ridge terminating at each of its ends in a nose and the noses thus formed providing in conjunction with the said shoulder, diagonal constrictions for the bow shackle in engagement with the clevis shank in position, when the clevis is not in engagement with the knuckle of the coupler and the said clevis is pulled with the shackle.

2. In and for a transition type coupler a clevis as claimed in claim 1 in which the inner face of the ledge is inclined such that when the knuckle is engaging the clevis, the shackle has the necessary free play in the said recess of the shank, but when the knuckle is not engaging the clevis, and is pulled by the shackle, then by virtue of the incline in the ridge the noses of the said ridge come into engagement with the bow shackle and in cooperation with the shoulder prevent the clevis from adopting a position substantially different from that when the said clevis was held by the said knuckle.

3. A transition type coupler employing a clevis of the type claimed in claim 2 in which the shackle opening in relation to the clevis is such that it can he slipped on the clevis only from that end of the clevis which is pivotally connected but not through the free end.

4. A transition type coupler as claimed in claim 3 in which the free end of the clevis has a female engaging contour complementary to the male engaging contour on the knuckle.

5. A transition type coupler as claimed in claim 2 in which an are shaped lug is provided on the clevis around its pin hole to engage a female depression in the coupler head, said lug having an arc subtending an angle of over 120, and being of dimensions as to permit the bow shackle to slip over to the shank.

6. A clevis as claimed in claim 1 in which the ridge or ledge extends all around the shank of the said clevis.

7. A transition type coupler as claimed in claim 1 characterized in the head at the end of the clevis shank is provided on its cooperating surface with a ridge or the like having a contour which cooperates with the knuckle and pushes or kicks it into locked position so that by rotating the clevis, locking is not only facilitated but automatically effected and the bow shackle can adopt a position suitable for engagement with the draw hook when the clevis is locked in position.

8. A coupler as claimed in claim 7 in which in order to facilitate the rotation of the clevis a vertical rod is secured thereto which helps in the rotational movement of the clevis when the bow shackle is in suspended position.

9. A coupler as claimed in claim 7 in which instead of having a ridge for kicking the knuckle, it is also possible to so shape the contour of the head of the clevis that the entire head acts to kick or force the knuckle into locking position.

10. A transition type coupler as claimed in claim 1 wherein the bearing surface of the shank of the clevis is so shaped that it holds the bow shackle to constrict its angular movement whereby the bow shackle is prevented from being free to adopt any other position which is normal to the clevis shank.

11. A coupler as claimed in claim 10 in which a shoulder is provided on the clevis corresponding to the shoulder at the end of the clevis shank to bear on either side of the bow shackle, when the bow shackle is engaged by the clevis.

12. A coupler as claimed in claim 10 in which a projection is provided on the front portion of the clevis shank which prevents the screw coupling from being hooked on to the draw hook when the clevis is in the fully opened or idle position by either the screw coupling being lifted in a clockwise direction in this position or by rotating the same in reverse direction over about 270.

13. A coupler as claimed in claim 12 in which the ridge is so modified that at the nose the said ridge has been extended so that the nose position extends more below the clevis shank than the shoulder whereby the nose portion is made farther away from the centre line of the clevis shank than the shoulder portion.

References Cited UNITED STATES PATENTS 1,599,038 9/1926 Bush 213-1l2 1,927,268 9/1933 Kinne 213-112 2,973,872 3/1961 Cope 213-112 DRAYTON E. HOFFMAN, Primary Examiner.

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