US1436246A - Pipe slip - Google Patents

Description

E. E. GREVE.

PIPE SLIP. APPLICATION FILED OCT. 11, 1921.

Patented Nov. 21, 1922.

Patented Nov. 21, 1922.

warren stares EDGAR E. GREVE, F BELLEVUE, PENNSYLVANIA.

PIPE SLIP.

Application filed October 11, 1921. Serial No. 506,986.

To all whom it may concern:

Be it known that I, EDGAR E. GREVE, a citizen of the United States, residing at Bellevue in the county of Allegheny and State of lennsylvania, have invented certain new and useful Improvements in Pipe Slips, of which the following is a specification.

This invention relates to pipe slips for use 0 in conjunction with apparatus employed in handling pipe, especially rotary well drilling apparatus.

In drilling operations, particularly those using the rotary system, it is customary to .5 mount, in a ring or spider, pipe engaging slips or wedges, the function of which is to hold the string of pipe in suspension while attaching or detaching different sections to the string which is being lowered or taken :0 out of the drill hole. These slips have, to a certain extent, caused trouble due to the binding effect resulting from the manner in which the back of the slip, or that portion of the slip which is in contact with the spider, fits.

A primary object of the present invention is to so change the shape of the outside or back surface of the slips as to reduce the tendency to bind.

Further objects of the invention are to provide means whereby a series of slips may be united to facilitate handling, but will be loosely connected in such manner as not to interfere with the proper functioning thereof, and to provide handles for each series of slips so connected, and to so.shape the slips as to facilitate the insertion of adjacent series of slips.

My invention may be readily understood by reference to the accompanying drawings in which:

Fig. 1 is a top plan view of a portion of a rotary showing slips, constructed in accordance with my invention supported thereline 11-11 in I . l ig. 2 is a vertical section on of Fig.1;land

l Fig. 3 is a perspective view-of one of the sis. r Y a n the drawings, A indicates the rotatable table of a rotary or otherapparatus, and B- indicates a spideror holder supported therein having aslightly conical -or tapered central opening therein. The wallsof the central opening are generally circular,as shown.

The spider or holder B may be of any preferred type and need not necessarily be used in a rotary, as slips and spiders are also used in other applications.

The several individual slips are designated by the numerals 1, 2, 3, and 4., and 1, 2, 3 and 4'. Slips 1 to 4 inclusive are connected to one series, and slips 1' to 4' inclusive are connected in another series, so that each series may be handled as units, as hereinafter described.

Each individual slip comprises a wedge shaped segmental body having its greatest thickness at the upper end thereof. The inner face a; of each slip is curved so as to be substantially concentric with the center of the opening through the spider or holder, and thereby engage the outside of a pipe passing centrally through the opening. The inner faces of the slips are serrated in a manner well understood, some ofthe slips having vertically extending teeth to hold the pipe against rotation, while most of the slips have horizontal serrations to hold the pipe against longitudinal movement.

Instead of the outside or back surfaces of the slips having a curvature which conforms to the circular walls of the spider, as has heretofore been the practice, the outer surfaces of the individual slips are turned to a radius shorter than the radius of the inside of the bore, as shown in a somewhat exaggerated manner in Fig. 1 of the drawings. With the slips so shaped, a full amount of contact area is obtained between the pipe and the slips, but the initial contact area between the slips and the spider is reduced and the outer faces of the slips do not initially contact with the spider throughout their entire area, as do the slips heretofore made, in which the curvature of the slip and the spider conform. Consequently, as the slips are forced further down into the cone shaped opening by the weight of the suspended pipe, a greater portion of the area of the slipsacrossthe periphery thereof will contact with the spider by reason of the ever diminishing radius of curvature of the cone shaped opening downwardly. With the old form of slip, as herein previously described, in which the center of curvature for theslips and the spider is the same,

any slight downward movement of the slips tends to force the slips inwardly. The periphery of each slip then has a curvature greater than the curvature of the opening, so that only the vertical edges of the slips contact with the walls of the opening in the spider, and these edges have a tendency to bite intothe spider walls, while thesurface of the slips between the edges is naturally forced out of contact with the spider. In other words, the periphery of the old form of slip assumes the position of a chord of a circle relatively to the inside walls of the spider opening, with the exception that it would becurved. With the present form of slip, the slip cannot move to such a position when in operation.

It is desirable that the individual slips be relatively small and loosely connected so I that several of them can be handled as a unit. As shown, I prefer to form two units which are substantially semi-circular. For connecting the slips, the intermediate units 2 and 3 and 2 and 3 are provided with a projecting lug or tongue 5 at one side thereof and a pocket or socket 6 at the other side, as shown in Fig. 3. In each of the tongues 5 are elongated openings 7, and passing through the body of the slips into the pockets are bolt receiving holes 8. A bolt or pin 9 passed through the holes 8 and the slots or elongated openings 7 in the tongues 5 serves to connect the adjacent slips. Slips 1 and 1' are provided with tongues 5, but it is unnecessary to form a pocket therein. The

tongues 5 on the slips 1 and 1' extend into the pocket on slip 2 and 2' respectively, and a similar pin or bolt 9 connects them. Slips 4 and 4 are provided with a pocket 6 to receive the tongue 5 on slips 3 and 3 respectively, but slips 4 and 4 need not be provided with the tongues thereon. The elon gated opening 7 in the tongues 5 in the sockets 6 allow for sufficient relative movement of the individual slips when being forced to pipe gripping position.

he upper edges of slips 1, 1 and 4t and 4 are beveled, as indicated at 10, so as to facilitate the entrance of either unit after the other has been inserted in the spider. Slips 1 and 40f one unit and slips 1 and 4 of the other unit have handles 11 babbitted or otherwisesecured thereto. These handles are preferably made of wire cable or rope. i

In use in a rotary, the slips are inserted into the spider after the pipe has been elevated for the purpose of attaching or detaching another section of pipe to the string. As the lifting and holding means at the top of the string is released, or the string lowered a slight distance, the wedge sha ed slips will be urged down into the spider, moving them together and inwardly gripping the pipe. The tongue and socket connection between the individual slips permits this relative movement thereof. By reason of the slips not conforming to the ment of the slips without departing from the invention and within the scope and contemplation of the appended claims.

I claim: 1. The coinbination with a spider having an opening therethrough, of pipe engaging slips which set into the opening, each of said slips having a pipe engaging face and a spider engaging face, the splder engaging face being designed to contact with the walls of the opening in the spider and being so shaped that its area of contact with the spider will increase across its periphery as the slip is lowered into the spider.

2. The combination with a. spider having an opening therethrough, the walls of which are circular, of a series of pipe engaging slips, each of said slips, having a pipe engaging face and a spider engaging surface, the spider engaging face having a curved area, the curvature of which differs from the curvature of the opening in the spider.

3. The combination with a spider having a circular opening therethrough, of a series of pipe slips adapted to be inserted therein, said slips having pipe engaging faces and spider engaging faces, the spider engaging faces being adapted to engage the walls of the circular opening in the spider and having a curvature struck from a radius shorter than the radius of the opening.

4. The combination with a spider having an opening therethrough, of slips adapted to be inserted in the openings, tongue and socket connections for joining a plurality of slips into units, and a handle for each unit.

5. The combination with a spider having an opening therethrough, of slips adapted to be inserted in the opening, tongue and socket connections for joining a plurality of slips into units, the end slips in each unit having beveled edges thereon to facilitate the insertion of other units to be placed adjacent thereto, and a handle for each unit.

6. The combination with a spider having an opening therethrough, of slips adapted to be inserted into the opening, said slips being provided with tongue and socket connections for joining a plurality of slips into units, said tongue and socket connection bein so arranged as to permit of a limited refit-ive movement of the individual slips in the unit. 9

7. A pipe slip construction for use in conmeans being so arranged as to permit of the nection wlth a spider comprising a plurality lateral relative movement of the individual of slips having pipe engaging inner faces slips in the unit. 10 and spider engaging outer faces, lateral In testimony whereof I aflix my signa- 5 faces on the slips, and cooperating connectture.

ing means on said lateral faces for joininga plurality of slips into units,- said connecting EDGAR E. GREVE.

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