US2797895A

US2797895A - Rotary table master bushings

Info

Publication number: US2797895A
Application number: US379990A
Authority: US
Inventors: Willy H Spiri
Original assignee: Abegg and Reinhold Co
Current assignee: Abegg and Reinhold Co
Priority date: 1953-09-14
Filing date: 1953-09-14
Publication date: 1957-07-02
Anticipated expiration: 1974-07-02

Description

Jill 2, 1957 w. H. SPIRI 2,797,895

ROTARY TABLE MASTER BUSHINGS Filed Sept. 14, 1953 INVEN TOR.

mm H. 5mm,

)f gzw ATTORNEY.

This invention relates to improved master bushing assemblies for use in well drilling rotary tables.

In drilling a well, it is customary to provide within the rotary table a master bushing assembly which is adapted to selectively serve as either a support for a number of pipe gripping slips, or a rotary driving member for a kelly bushing. The present invention is concerned with a bushing for serving these functions, and which is of a general type comprising an outer main bushing body, and one or more inner slip sections positionable within the outer body and forming a downwardly tapering bowl for receiving the usual pipe supporting slips. A bushing assembly of this type is shown in copending application Ser. No. 371,857, filed July 24, 1953, now Patent No. 2,763,468, on Well Drilling Master Bushing Assemblies by Walter A. Abegg, and owned by the assignee of the present invention.

The general object of the present invention is to provide means for preventing accidental or unwanted movement of the slip bowl sections relative to the outer bushing body in a bushing assembly of the above type. More specifically, the bushing may be constructed to positively prevent or limit either rotary or upward movement of the bowl sections, and preferably both. As will be understood, it is desirable to prevent rotation of the bowl sections relative to the bushing body in order to assure effective transmission of rotary movement from the table to a contained pipe. Further, it is desirable to prevent upward movement of the bowl sections, in order to retain them against such movement upon elevation of the contained pipe and slips.

I prefer to so form the movement limiting means as to be easily releasable when desired, to thus permit ready removal of the slip bowl sections from the outer bushing body. For this purpose, I may employ a latch or holding element which is movable relative to both the main body of the device and its inner slip bowl sections between active and released positions. This element may be movably carried by the bushing body and be engageable with a positioning shoulder or shoulders on the bowl sections. In the preferred form of the invention, the latch element is movable into an arcuate groove formed in the wall of one or more of the slip bowl sections, and acts to limit bowl movement by engagement with the walls of the groove. For most effective bowl control, two bowl sections are employed, and are individually retained against movement relative to the bushing body by two separate latch elements carried at diametrically opposite locations on the body.

The above and other features and objects of the present invention will be better understood from the following detailed description of the typical embodiment illustrated in the accompanying drawing, in which:

Fig. 1 is a plan view of a master bushing assembly shown positioned within a well drilling rotary table;

Fig. 2 is a section taken on line 22 of Fig. 1;

Fig. 3 is an enlarged vertical sectional view of the bowl locking mechanism of the invention; and

lice

Figs. 4 and 5 are fragmentary horizontal sections taken on lines 4-4 and 55 of Fig. 3.

In Figs. 1 and 2, I have shown at 10 the central portion of a well drilling rotary table, containing a vertically extending opening within which is received a master bushing assembly generally indicated at 11. The upper portion 12 of the bushing receiving opening in the rotary table is square in horizontal section, while the lower portion 13 is vertically cylindrical and of reduced horizontal dimension.

The bushing assembly itself includes an outer one piece rigid essentially annular body section 14, and a pair of complementary inner slip bowl sections 15. In use, the inner slip bowl sections 15 are adapted to receive a pair of conventional slips 16 for gripping and supporting a pipe 17 within the rotary table. At a pair of diametrically opposite locations outer body 14 of the bushing carries a pair of locking units 18 adapted to prevent or limit both upward and rotary movement of the sections relative to body 14.

Body 14 is shaped externally substantially in correspondence with the rotary table opening within which it is received. Thus, body 14 has an upper externally essentially square portion 19 received within square portion 12 of the rotary table opening, and has a lower essentially cylindrical portion 20 engaging cylindrical portion 13 of the table. The upper square portion 19 of body 14 may be cut off at an angle at its corners 21, as shown. Extending between its upper square and lower cylindrical portions, table 10 has an annular horizontal shoulder 22 engaging a shoulder 23 on body 14 to positively support the body within the table. The body shoulder 23 is essentially annular and faces downwardly and is interrupted only at the locations of locking units 18.

The bowl engaging portion of body 14 has a pair of inner

cylindrical surfaces

24 and 24a, the upper of which is of a diameter somewhat greater than the lower, and between which is formed an annularxnpwardly facing horizontal shoulder 25 for engaging a corresponding shoulder on the slip bowl sections to support those sections in the body. The two bowl sections 15 are horizontally semi-circular and have semi-cylindrical outer

surfaces engaging surfaces

24 and 24a in body 14. The surfaces within bowl sections 15 form together a downwardly tapering or converging recess 26 for receiving the conventional slips 16.

Above bowl sections 15, the vertical opening through body 14 has an upper non-circular portion 27 for receiving and driving a conventional kelly bushing. In accordance with the usual practice of forming the kelly bushing to be externally essentially square, this upper portion 27 of the body opening may be correspondingly essentially square, and for that purpose may have corner portions 28 projecting radially outwardly from four evenly spaced locations about the body opening, to receive the four corners respectively of a kelly bushing. If desired, these corner portions 28 of the upper non-circular part of the body opening may be somewhat enlarged at their exact corners 29, as shown.

Each of the lock units 18 includes a lock element 35) which is mounted within a horizontally extending opening 31 in body 14 for horizontal movement between the full line and broken line positions of Fig. 4. The two elements 30 are positioned at diametrically opposite locations and have inner slightly tapering portions 32 which are movable into and out of arcuate outwardly and upwardly opening recesses 33 in the upper end portions of the outer walls of slip bowl sections 15. These recesses 33 form together an essentially annular recess, which is interrupted at a number of evenly circularly spaced locations by portions 34 of the slip bowl sections extending out to the full diameter of the sections. As will be understood, the inner portions 32 'of lock elements 30, when in their full line Fig. 4 positions, are'engageable by pertions or shoulders 34 of the slip bowl sections to positively limit rotary movement of the bowl sections within body 14. 'Also, engagement of lock element portions 32 with bottom walls 35 of recesses 33 acts to prevent upward withdrawal of the bowl sections from body 14.

' Lock elements 32 are actuable horizontally between their active and released positions by means of a pair of operating members 36, which are mounted for rotation about vertical axes by reception of their cylindrical portions 37 within vertical bores 38 in the body. A pair of retaining screws 137, threadedly and removably connected into body 14, engage upper annular surfaces 138 of cylindrical portions 37 of the members 36, to releasably retain members 36 against upward withdrawal, while permitting rotation of these members. Members 36'have lower cylindrical portions 39 which are positioned eccentrically with respect to the axes of rotation of members 36, and are movably received within laterally elongated openings 40 in lock elements 30. As will be appreciated, rotation of one of the members 36 about its vertical axis acts to swing the lower portion 39 of that member eccentrically in a manner moving one of the lock elements 30 between its full line and broken line positions of Fig. 4. Preferably, 180 swinging movement of member 36 acts to move the portions 39 thereof between its two active and released positions.

Each of the members 36 has at its upper end a portion 42 of a non-circular (typically square) section, about which is received a tubular sleeve 43 which is internally of corresponding non-circular configuration, so that the sleeve is movable vertically relative to member 36, but is adapted to turn member 36 about its axis. Sleeve 43 carries a diametrically extending handle element 44, by which the sleeve is movable vertically between the elevated broken line position of Fig. 3, in which the handle is rotatable, and the lowered full line position. Such vertical movement is limited at the illustrated full line and broken line positions by engagement of a pin 45, fixed to and extending transversely through sleeve 43, with the ends of a vertically extending recess 46 formed in the side of member 36. In the lowered full line position of each handle, the ends of handle element44 are receivable within a recess 47 in the upper surface of body 14. This recess. is so shaped as to receive the handle element in either of two rotary positions relatively ofi'set 180, but not in intermediate positions, to thereby positively lock the handle and member 36 in either the active position or retracted position of element 30.

In using the illustrated master bushing assembly, the various parts will normally be positioned as shown in the figures, with elements 30 projecting into recesses 33 in bowl sections 15, to lock the bowl sections against upward withdrawal from body 14 and to limit rotation of the bowl sections within the body. Rotary movement may. thus be transmitted from body 14 tobowl sections 15 for rotating pipe 17 by means of the rotary table. At the same time, the retention of bowl sections 15 against upward withdrawal prevents their upwardmovementwith slips 16 when the slips are being removed from the bowl to. release the grip on pipet17.

When the table is being used to turn a drill string by action against a kelly, the slips 16 are removed from bowl sections 15, and the square portion of a kelly bushing is received within the uppernon-circular portion 27 of master. bushing body 14. If the occasion arises for passing a drilling bit or other enlarged element through the master bushing, handles 44 are elevated to their broken line positions of Fig. 3, following which they are rotated to release lock elements 32 and permitupward withdrawal of bowl sections 15, thus enlarging' the opening within the bushing assembly for passing the bit or other member. For facilitating such removal of bowl sections 15, eachof .thesesections may'have a pair of passages 48; extending. through its. side :-:wall,':' and ;.into

which a hook or other tool may be inserted to lift the section out of-the bushing body. A pair of similar diametrically opposite openings 49 may be formed in body 14 of the bushing assembly.

I claim:

1. A well-drilling master bushing assembly comprising an outer rigid body adapted to be received and supported in a rotary table recess and containing an opening extending vertically therethrough, said body having an upper externally non-circular portion to be received and supported in and rotatably driven by an upper non-circular portion of said rotary table recess, said body having a lower portion of externally reduced dimension extending downwardly into a lower portion of said rotary table recess, said upper non-circular portion of the body extending laterally beyond said lower portion, and a plurality of slip bowl segments supported in a lower portion of said body opening and having downwardly converging inner slip engaging surfaces, means for supporting said slip bowl segments in said'body, said outer body comprising a onepiece rigid member which is circularly continuous entirely about said opening so that lateral expanding forces exerted against the. body are taken directly by it without transmission to the rotary table, said slip bowl segments being completely removable upwardly from said outer body to pass a drill bit through the body, the material of said body forming a non-circular upper portion of said opening adapted to receive and directly engage and rotatably'drive a mating non-circular portion of a kelly bushing, said slip bowl segments being positioned low enough in the body to allow reception of said non-circular portionof the kelly bushing in said upper non-circular portion ofjthe body opening in direct rotary driving engagement with the body at that location without removal of the slip bowl segments from the body, a lock element, means movably mounting said lock element to said body at a location laterally, opposite one of said slip bowl segments and for movement relative to the body between activeand released positions, a shoulder on said one segment movable along a path in a. predetermined direction upon predetermined displacement of the slip bowl segment, said lock element in said active'position being located in said path .of movement of said shoulder and thereby acting to hold said one segment against said predetermined displacement, said lock element in released position being out of said path to release the segment for said displacement, said shoulder facing at least partially in said direction, said means movably mounting the lock element including means holding the lock element against movement in said direction relaive to the body in said active position, a movable actuating member supported in'and extending upwardly through said upper non-circular portion of the body and extending upwardly beyondsaid slip bowl segments and horizontally opposite said upper non-circular portion of said opening,-an operating connection between said actuating member and said locking element for actuating said lockingvelement between said active and released positions in accordance with movements of the actuating member, a handle mounted for movement relative to the body at the upper end .of said actuating member and manually operable from the upper end of said body, and a connection between said handle and said actuating member forv actuating the member and lock element in accordance with movements of the handle.

2. A well-drilling master bushing assembly as recited in. claim 1, including means mounting said handle for manual rotation toactuate said lock element and for axial movement relative to said body between an upper position and a lower position, there being a shoulder on said-body positioned in the rotary path of the handle in said lower position of the handle but not in said upper position andjthereby acting to retain the handle against rotation foractuating the locking element in said lower position.

3. A well-drilling master bushing assembly as recited in claim 1, in which there are two of said handles, two actuating members, and two locking elements carried by the body, for engaging two of said slip bowl segments respectively.

4. A Well-drilling master bushing assembly as recited in claim 1, in which said locking element and said shoulder on said one segment are engageable to releasably retain the segment against upward movement relative to said body.

5. A well-drilling master bushing assembly as recited in claim 1, in which said locking element and said shoulder on said one segment are engageable to releasably retain the segment against upward movement relative to said body, said one segment having an additional shoulder engageable by said lock element to prevent rotary movement of said one segment relative to the body.

6. A well-drilling master bushing assembly as recited in claim 1, in which said lock element is movable horizontally relative to said body between a locked position and a released position, said actuating member and handle being mounted to said body for rotary movement about essentially an upwardly extending axis, said member hav- 6 ing a portion at its lower end positioned eccentrically with respect to said axis and received within a recess in said lock element to actuate it between said locked and released positions in accordance with rotary movement of said member and handle.

References Cited in the file of this patent UNITED STATES PATENTS 277,398 Wise May 8, 1883 1,506,583 Hoffman Aug. 26, 1924 1,507,325 Reynolds Sept. 2, 1924 1,513,388 Greve Oct. 28, 1924 1,679,955 Bartholomew Aug. 7, 1928 1,771,391 Black July 29, 1930 2,008,774 Spalding July 23, 1935 2,030,318 Pranger et al. Feb. 11, 1936 2,115,279 Pennington Apr. 26, 1938 2,182,793 Davidson Dec. 12, 1939 2,282,617 Spalding May 12, 1942 2,422,383 Young June 17, 1947 Pearce Nov. 20, 1951