Elevator device

Aug. 19, 1947. G. e. mullinix 2,425,753

ELEVATOR DEVICE

Original Filed Dec. 9, 1941

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Patented Aug. 19, 1947

2,425,753

UNITED STATES PATENT OFFICE 2,425,753 ELEVATOR DEVICE

Gird E. Mullinix, San Marino, Calif., assignor to Byron Jackson Co., Vernon, Calif., a corporation of Delaware

Original application December 9,1941, Serial No.

422,224, Divided and this application July 14, 1944, Serial No. 544,998 ---,

Chaims.

This invention relates to well pipe elevators and the like, and is directed particularly to improvements therein which are calculated to reduce the manual effort involved in applying such devices to and removing them from the pipe.

As is well known to those familiar with oil well drilling -.operations, it is necessary to periodically remove the string of -drill pipe from the well to replace a worn drilling bit. The drill -string is separated into sections,-or “stands” of from 60 to 90 feet in length, Which are racked in an upright position in the derrick. A member of the drilling cre-w, usually termed the derrick man, is stationed on a platform high, in the derrick, to unlatch the elevator from the upper end Of each -stand of -pipe as it is disconnected from the drill string and racked in the derrick, and to latch the elevator about each successive stand as the pipe is run back into the well.

The -task of the -derrick man is most arduous when running the string of pipe back -into the well. During this operation, as each successive stand of pipe is connected to the drill- string, the drill string is lowered into the -well while -supported in the elevator, until the upper end of the newly -added stand is just above the rotary table. The weight of the pipe is then· transferred -from the elevator to the pipe slips set in the table, and the elevator is then removed -from the pipe and raised in the derrick to pick up the next -stand. Meanwhile, the derrick man has moved‘the next stand into position to be engaged by the elevator. In order to save as- much time as possible, the driller at the hoist .controls prefers- -not to- decrease the hoisting .speed by an. appreciable amount as· the empty- elevator reaches the -derrick man, thus requiring the derrick man to grasp the elevator as it approaches his level and -draw it toward him and latch it about -the pipe while the elevator is travelling upwardly at a substantial speed. It is thus apparent that split-second timing on the -part of the derrick· man is required. For this -reason, -it is· of utmost importance that the elevator hang from the supporting links in such a position that it can toe- grasped bythaderrick man and latched about the pipe -with a minimum of effort and in the shortest possible· .time. The. instant invention is .directed particularly to this phase of drilling.operations.

Well Pipe.etevators.:now in· use .are of two general classes, namely: .(1:)- thosein which,:the supporting ears.are formed- on diametrically opposite sides: of .a U-shaped body defttting .anopen-si^d pipe·-recess, and to which·. the epen side .of the reeessis etosedhy asdoor orgatepivotally mW(Cl. 294—90) ed on the body on an axis at one side of the-open recess, this type being generally referred to as side-door” elevators; and (2) those comprising two substantially -symmetrical sections each havS ing a supporting ear and meeting -in a diametric plane extending at right angles to the -plane of the supporting ears, and toeing -hingedly connected at the rear side -of the pipe recess and releasabl-y latched together at the -front side, 'This 10 -type: is usually referred to as '“center latch” or “double door” elevators.

It is characteristic of .center latch elevators that as the sections are swung outwardly relative, to each -other about their pivotal axis, the -rear 15 portion of the .elevator moves toward the ’Vertical plane of support extending through -the supporting ears, thus shifting the center of gravity of .the elevator forwardly of .that plane. This creates a tendency for the front side of the .ele'20 vator to tilt downwardly to- .an extent to again dispose the center of .gravity in. the aforesaid .plane of support. -TSMs tilting movement is .an advantage in .one respect for the: following reason. Inasmuch .as the -supporting ears .are each 25 formed on one -of .the .elevator sections, the opening movement .of the section increases .the .distance between the ears-tbps causing the elevator links· -to .assume .downwardly .diverging: positions with respect to each other. The tendency of the 30 uhks to return to their normal .suspended positions tends to close the elevator if the links are both suspended from a single hook, and, even if the finks are separately suspended at laterally spaced points on .a .multiple hook, the closing •35 tendency Is usually .sufficient fp prevent·,the elevator .from- reroaining fully -open unless it- tilts downwardly in front. It w® :be apparent, however,, that whenthe front portion of: the elevator is tilted .-downwardly to .dispose the pivotal axis 40 taanlncSnedcpqsition, the-weight .of theeievator constitutes a force, one component .of .which®xerts a turning moment about the pivotal axis in eiwsition to: the -closing force exerted fey the links.

For the foregoing reasons, it has been customary to allow center latch elevators to.· “break down,” pr tilt downwardly in front, in order to maintain them in open position Wilde being raised: in the derrick to pick up a stand .of pipe;

This practice: has the: .disadvantage,, however; of requiring the derrick .man to tilt' the elevator back to- Upright, or nearly upright, position in order to align the pipe,b.ore&lt;of the: elevator .with the pipe before the. .elevator can. :be. latched ton 55 the pipe.

2,435,753

The instant invention has as its principal object the provision of an elevator, particularly of the center latch type, which will remain in open position without being tilted downwardly in front.

A further object of the invention is to provide an elevator having incorporated therein a releasable latch mechanism acting between the elevator sections to releasably retain the elevator in open position.

A still further object is to provide an elevator having means incorporated therein for exerting a force yieldingly maintaining the elevator in open position, the arrangement being such as to require only slight manual effort to effect the initial closing movement of the elevator sections, and the aforesaid force being rendered inactive upon such initial closing movement.

A still further object is to provide an elevator having a novel spreading latch housed within a recess in the bore of the elevator in a protected location.

The manner in which the foregoing and other objects are attained will be apparent from the foregoing detailed description of a preferred embodiment of the invention, reference being had to the accompanying drawings wherein:

Fig. 1 is a top plan view of an elevator embodying the invention, the rear portion of the elevator being broken away on substantially the line I—I of Fig. 3 to illustrate details of a preferred form of yieldable spreading means;

Fig. 2 is a view similar to Fig. 1, but showing the elevator in closed position;

Fig. 3 is a vertical view taken on line III—HI of Fig. 1, showing the yieldable spreading means in elevation.

Referring to the drawing, I have shown my novel spreading latch as applied to a well-known type of elevator such as is used for handling external upset drill pipe—that is, pipe having a tapered upset at the base of the tool joint. The elevator comprises generally a pair of sections 10 and i ί pivotally interconnected at the rear side by a hinge pin 12, and having a latch 12a for detachably securing the forward sides of the sections together about a pipe. Semi-circular bores 13 and 14 are formed in the inner walls of the respective sections and cooperate to form a circular pipe recess when the sections are closed. As most clearly shown in Fig. 3, a downwardly tapered seat 15 is formed in the bore, and conforms to the tapered upset on the pipe to support the pipe in the elevator. Each section is provided with a pair of outwardly projecting upper and lower ears 16 and 17 defining link recesses in which the lower eyes of elevator links are received and releasably confined by detachable link retainer blocks 18. A pair of handles 19 project outwardly from the forward sides of the sections and a handle 20 is formed at the rear side of one section, to aid in the manual manipulation of the elevator. For a more complete description of the detailed construction of the elevator, reference is made to U. S. Letters Patent No. 2,067,663 to Herbert E. Grau, dated January 12, 1937.

It will be observed with particular reference to Fig. 3 that the bore of the elevator body is enlarged between the upper bores 13 and 14 and the lower centering rib 21, providing recesses 22 and 23 in the respective elevator sections 19 and 11, one of which recesses forms a convenient place for mounting a spring detent 24. The detent comprises a flat, elongated bow spring, the free end of which is rounded over at 25 to provide a cam surface 26. The opposite end of the spring is turned outwardly at 27 and engages a slot 28 formed in a retainer plate 29 welded or otherwise secured to the wall of the recess 22 in the elevator section 10. The outer wall of the retainer plate is grooved lengthwise thereof from the slot 28 to the remote end of the plate, to receive the spring 24 and retain it firmly in place.

As shown most clearly in Fig. 3, the hinge pin 12, which pivotally connects the two body sections together, extends through upper and lower hinge lugs 30 and 31 on the body section 10 and a central hinge lug 32 on the body section It. A cam projection 33 is formed on the central hinge lug 32 in the horizontal plane of the spring 24, and is provided with a forward, steeply pitched cam surface 34 (Fig. 2) and a rear cam surface 35 of relatively flat pitch. A relatively wide clearance is provided at 36 (Fig. 1) between the hinge lug 32 and the adjacent wall of the body section 10, to receive the projection 33 when the body sections are closed.

It will be observed that the outward flexing of the spring detent 24 is limited by engagement thereof with the wall of the recess 22, and it will be noted in particular, with reference to Fig. 2, that a slight clearance is provided between the curved-over end 25 of the detent and the wall of the hinge lug 32. Thus the only frictional engagement between the detent and the hinge lug is during the time the detent engages the cam projection 33. In this manner, frictional wear on the detent and hinge lug is reduced to a minimum, and the detent is wholly inactive once it has been disengaged from the projection and hence it offers no resistance to closing of the elevator after the initial closing movement has been effected.

The operation of the spring detent will be apparent from the foregoing description. When removing the elevator from the pipe, the sections are spread apart as far as is permitted by the usual opening stops (not shown) on the body sections. This opening movement is slightly more than sufficient to cause the cam projection 33 to pass to the right of the curved end 25 of the spring, to the position shown in Fig. 1. In passing the spring end, the flat cam surface 35 on the projection engages the curved cam surface 26 on the spring and flexes the spring outwardly. Because of the relatively flat wedge angle of the cam surface 35, the flexing of the spring offers no substantial resistance to opening movement of the elevator sections. However, when the steeply pitched cam surface 34 on the opposite side of the projection engages the spring end, the force required to flex the spring inwardly is considerably greater. By suitably shaping the cam surface 34 and by the selection of a spring of proper strength, the resistance offered thereby may be such as to only slightly exceed the closing force exerted on the elevator by the links. Hence, upon application of slight manual pressure on the elevator handles 19 in a closing direction, the spring may be flexed inwardly to allow the projection 33 to pass it. After the projection has passed the spring, the closing of the elevator is effected without interference by the spring.

From the foregoing description of a preferred embodiment of the invention, it will be apparent that relatively simple but highly effective means have been provided for insuring that the elevator is maintained in open position without being tilted downwardly in front, thus enabling the derrick man to quickly and easily apply it to the pipe by simply drawing it toward him, without

2,425,753 having to tilt it into alignment with the pipe. The provision of means for releasably maintaining the elevator sections in open position not only insures proper alignment of the elevator with the pipe, but also prevents inadvertent closing of the elevator due to vibration or swaying as it ascends or descends in the derrick.

It will be apparent to those skilled in the art that the novel spreading means may assume various forms, and it is to be understood that the form shown and described herein is solely for illustrative purposes. Hence the invention is not limited to the precise form shown herein, but is of the full scope of the appended claims.

This application is a division of the copending application of Gird E. Mullinix and Allen E. Hambly, Serial No. 422,224, filed December 9,1941, now matured into Patent No. 2,354,217, issued July 25, 1944.