US2809856A

US2809856A - Safety clevis

Info

Publication number: US2809856A
Application number: US479879A
Authority: US
Inventors: Emmett L Alexander
Original assignee: GEORGE E FAILING Co
Current assignee: GEORGE E FAILING COMPANY Inc ENID OK 73701 A CORP OF; GEORGE E FAILING Co
Priority date: 1955-01-05
Filing date: 1955-01-05
Publication date: 1957-10-15
Anticipated expiration: 1974-10-15

Description

Oct. 15, 1957 E. L. ALEXANDER SAFETY CLEVIS 2 Sheets-Sheet 1 Filed Jan. 5, 1955 INVENTOR. EmmeffL. A/exande/r MMYMMM ATTORNEYS.

.t qn- V FigrGi-s a-vertical section showing the latch-pin in United States SAFETY CLEVIS Emmett L. Alexander, Enid, kla., assignor to George E. Failing Company, Enid, 0kla., a corporation of Delaware This invention relates to clevises and similar connective devices of the type disclosed in the Caldwell Patent No. 2,232,997, issued February 25, 1941, and has for its principallobject to provide an improved device of this character.

For example, the device of the patent has been-satisfactory but it is diificult to register the latch-lug with the pass therefor, particularly in the larger sizes of clevises and when rapid manipulation of the pin is required. This is because the coil spring of the patented device must be held in compression when the latch lug is being registered with the pass therefor. Also, the spring must be compressed while the lug is projected through the pass to bring the latch-lug into locking position.

Therefore, it is a further object of the invention to provide a structure wherein the pin is free of spring actionuntil the latch-lug has cleared the outer end of the pass, and whereinthe spring action which is required to lock the pin is effected by a camming action upon rotation'of the pin to set the latch lug.

Other, objects of the invention are to provide a structwo which is more streamlined and less likely for accidental release through fouling of the equipment with an obstruction; to provide a pin and knob' structure which facilitates registry of the latch-lug with the pass and to provide a spring arrangement wherein the spring is substantially free of compression whenthe latch-lug is in latching position.

In accomplishing these and other objects of the invention, as hereinafter pointed out, I have provided .improved structure the preferred form of which is illustrated in the accompanying drawings wherein:

Fig. 1 is a perspective view of a clevis of the rope socket type and embodying the features of the present invention, the pin being shown in latched position.

Fig. 2 is a similar view but showing the latch pin moved along the cam toward latching position.

Fig. 3 'is'a similarview showing the pin in retracted position to effect connection of the clevis with a bail of a swivel or the like. g I Fig. 4is -a "fragmentary sid'e elevational view of the clevis from the knob side.

Fig. 5 is a fragmentary section through the pin with the body of the clevis and spring being shown in elevalocking position with the pin of the clevis supporting a bail, the bail being shown in dotted lines and the spring in relaxed condition.

Fig. 7 is a fragmentary section similar to Fig. 6 but showing the pin moved to a position for unlocking the latch-lug and showing the spring in compressed condition.

Referring more in detail to the drawings:

1 designates a clevis constructed in accordance with the present invention and which includes a stirrup 2 having a substantially truncated cone-shaped head 3. Depending from the base of the head on opposite diametrical atent O ice sides thereof are spaced apart

parallel straps

4 and 5. The

straps

4 and 5 are illustrated as being integral with the head and terminating in substantially

circular ears

6 and 7. The head 3 has an inner conical bore 8 in which the splayed end of a cable 9 is anchored by babbitting 10 or the like as in the usual manner of attaching a socket to a cable. The space between the

ears

6 and 7 form a passageway 11 for containing the bail 12 or other device to which the clevis is to be connected.

The

ears

6 and 7 have axially aligned

openings

13 and 14 and rotatably and slidably contained therein is a pin or gate 15 therein that extends across the passageway 11 of the clevis and through a space between the legs 16 of the bail to connect the bail with the clevis.

The pin 15 includes a cylindrical body 17 having a slidable rotating fit within the

openings

13 and 14. The pin 15 has a knob 18 of larger diameter than the outer diameter of the body 17 to form an annular shoulder 19 for contacting the spring 20. The outer side of the knob 18 has an exterior face 21 to fit the palm of the hand. Projecting from one diametrical side of the knob 18 is a lever portion 22 to facilitate turning of the pin 15 within the

openings

13 and 14.

- The spring 20 is mounted on the cylindrical body 17 of the pin between the shoulder 19 of the knob 18 and the outer side face 23 of the ear -6. The cylindrical body 17 of the pin is of suflicient length to accommodate the spring 20 in substantially relaxed position and to project slightly beyond the outer face 24 of the ear 7. The end of the pin opposite the knob 18 has a flat face 25 and extending radially from the side of the pin is a latch-lug 26 that is preferably provided with a rounding end 27 to seat, in one position of the pin, within a correspondingly shaped recess or socket 28 on the inner face side 29 of the ear 6, the recess 28 being located on the side of the opening 13 opposite the head 3 of the clevis. When the pin is retracted and the handle portion 22 of the knob is turned downwardly, as shown in Fig. 3, the latch-lug 26 will enter the recess 28 and the end face 25 of the pin will besubstantially flush with the inner face 29 of the ear 6 thereby providing an open and uninterrupted entrance to the passageway 11.

Located within the ear 7 in aligned registry with the recess 28 is a groove or pass 30 arranged radially of the opening 14 and of sufficient size and shape to permit movement of the latch-lug 26 therethrough when the pin is projected across the space between the

ears

6 and 7 for closing the entrance and whereby the latch-lug is caused to move beyond the outer face 24 of the ear7 from which position the pin is adapted to be moved to the face 24 and which follows the curvature of the opening 14, as shown in Figs. 1, 3 and 4. With this arrangement the bottom 34 of the recess or socket 31 is substantially in plane with the outer face 24 and the entrance to the socket is at the top or highest lift portion 35 of the cam track 33. The opposite side face 36 of the recess 31 projects outwardly beyond the terminal portion of the cam track to provide a stop for the latchlug 26 when the latch-lug reaches the recess or socket 31. The face 37 of the boss on the side opposite the cam track 33 is not important but may slope downwardly to merge with the outer face 24. It is thus obvious that the recess or socket 31 has a different position than the corresponding recess in the device of the above mentioned patent in that, the bottom face 34 of the recess is located approximately in the plane of the outer face 24 so that when the inner face of the latch-lug 26 is engaging' the 'face 34, the spring 23 is not compressed or at the most to a very limited extent. When the pin is rotated in the direction of the arrow the spring is compressed and a resilient action stored therein because the latchlug rides up the inclineof the cam track. This stored up action in the spring causes the latch-lug to snap into the socket when the latch-lug rides off the end of the cam track, but since the bottom of the recess corresponds in planular relation with the start of the cam track the action in thespring is expended or substantially released when the latch-lug is'in the socket. Therefore it is only necessary to compress the spring a distance correspond ing to the lift of the cam track and this compression need not be more than that required to snap the latchdug into the socket and'to'retain the latch-lug from accidentally shifting out of locked position. Consequently the "spring 20 of the present invention has an effective length corresponding to. the lift or rise of the cam track. The spring 20 preferably comprises a disk formed of spring material and shaped to provide a con-cavo-convex body or dome portion 38 having an axial opening 39 to freely pass the pin 17 therethrough. The peripheral portion 41'of the spring terminates in a plurality of outwardly curving fingers 40 that are formed by radially slitting the periphery of the disk. When the spring is positioned on the pin with the pin passing through the opening 39, the fingers '40 bear against the outer face 23 of the ear 6. The spring remains in relaxed condition until the head of the pin is drawn into engagement therewith by the cam track and is compressed only as the latch-lug 'is caused to ride'up the cam track. The compression in the spring is confined principally to the finger portions thereof which flexand flatten against the face 23. This provides suflicientjspring' action to shift the latch-lug into engagement with the recess 31 when the latch-lug slides off the high-end of the cam track. It is obvious that during the entire sliding movement of the pin axially through the

openings

13 and 14 it is entirely free from the effects of the spring and that the spring comes into play only during turning movement of the pin. Therefore, the pin being free of the spring it is easily manipulated to register the latch-lug thereon with the pass 30. Also, the pin is shifted to cause the latch-lug to pass through the pass without making it necessary to overcome any resistance by the spring. I

I In using the clevis constructed and assembled as described and assuming that the clevis is fixed to the cable 9 of the tackle of a drilling string, and assuming that the pin is in retracted position, the end face 25 thereof in plane with the inner face of the ear 6 and the latchlug in the recess 28, the bail or link of the swivel of the drilling string is passed into the stirrup. After the bail is in position in the stirrup as shown in dotted lines in Fig. 6, the operator presses against the knob 18 to pass the pin between the legs of the bail and into a position where the latch lug is registered with the entrance to the pass 30 and passes therethrough before the head of the pin engages the spring. When the latch-lug is on the euterside of the ear 7 the handle portion 18 of the pm 1s turned in a clockwise direction, as indicated by the arrow in Fig. 3, to turn the pin 15 in the

openings

13 and 14 and cause the latch-lug to ride upwardly along the inclined cam track 33 to effect compression of the spring for providing the spring action necessary to retract the pin and bring the latch-lug into locking relation with the notch or socket 31.

To release the bail from the clevis, pressure is again applied against the knob 18 of the pin to effect sufficient compression of the spring 20 so that the latch-lug 26 passes out of the recess 31 and to permit turning of the pin in an anti-clockwise direction. When the latch-lug has reached the start of the cam track, the spring is unloaded and the pin is easily retracted through the pass 30, across the passageway 11 between the ears of the clevis, and the latch-lug is seated in the recess 28. The end face of the pin is then clear of the bail 12 and the clevis is readily withdrawn from the bail.

While I particularly illustrated the invention as being carried out in the form of a rope socket it is obvious that the invention may be carried out in other types of clevis, without departing from the spirit of the invention.

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

A safety clevis including a stirrup and a pin, said stirrup having spaced apart strap portions, each provided with an opening, said opening in one strap portion being axially aligned with the opening of the other strap portion and forming annular bearing faces for slidably and reciprocably engaging the pin, one of said strap portions having a groove extending inwardly from the annular face portion thereof extending through an outer face of said strap portion, a cam on said one strap portion and rising from said outer face to terminate in a recess at the opposite diametrical side of the groove, said recess having a bottom in plane with said face of the strap portion and said strap portion having a stop face projecting outwardly beyond the terminal portion of the cam and on the opposite side of said recess, said pin having a radial lug on one end to pass through said groove and a knob on the other end of the pin at the outer side of said other strap portion, a spring element on the pin between said knob and said other strap portion and adapted to be compressed therebetween, said pin being of such length that when the spring is relaxed the lug projects from said face of the said one strap portion and in position to engage the rise of the cam when the pin is rotated for compressing the spring element between the knob and said other strap portion to bring the lug into engagement with said stop and where the spring element retracts the lug into the said recess responsive to the stored up action in said spring element and to lock the pin and to leave the spring element relaxed when the lug reaches the bottom of the recess.

References Cited'in the file of this patent UNITED STATES PATENTS 437,388 Wooster Sept. 30, 1890 2,232,997 Caldwell Feb. 25, 1941 2,311,592 Hapanowicz Feb. 16, 1943 FOREIGN PATENTS 573,519 GICat'BIitain---- ----a- Nov. 23, 1945