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Publication numberUS3760469 A
Publication typeGrant
Publication dateSep 25, 1973
Filing dateDec 9, 1971
Priority dateDec 9, 1971
Publication numberUS 3760469 A, US 3760469A, US-A-3760469, US3760469 A, US3760469A
InventorsBrown C
Original AssigneeBrown C
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Automated pipe-handling slips
US 3760469 A
Abstract
A power drive is employed to move wedge shaped slip members radially into gripping engagement with a pipe which extends axially through a slip assembly. Friction teeth on the slip members engage the pipe and subsequent axial movement of the pipe pulls the slips against inclined seating surfaces to increase the grip on the pipe. A power drive acting through the slip assembly is also provided for rotating the gripped pipe.
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Description  (OCR text may contain errors)

Umted States Patent 11 1 1111 3,760,469 Brown Sept. 25, 1973 AUTOMATED PIPE-HANDLING SLIPS 1,844,378 2/1932 Campbell 24/249 DP 2,587,893 3/1952 Pridy et 24/263 DH UX [76] c'cem Bmwn, 8490 Katy 3,579,752 5/1971 Brown 24/263 DQ Freeway, Houston 77024 3,670,374 6/1972 Hayes 24/263 DA [22] Filed: Dec. 9, 1971 Primary Examiner-Donald A. Griffin PP 4 206,259 Attorney-Carlos A. Torres et al.

52] u.s. c1 24/263 DQ, 24/263 DK ABSTRA T [51] Int. Cl. Fl6l 7/00 A power drive is employed to move wedge shaped slip [58] Field of Search 24/249 DP, 263 D6, members radially into gripping engagement with a pipe 24/263 D, 263 DA, 263 DK, 263 D0, 263 which extends axially through a slip assembly. Friction DH, 263 DM, 263 KC, 263 CA, 263 KH, 263 teeth on the slip members engage the pipe and subse- KS, 263 DN, 263 DP, 263 DJ, 263 DL quent axial movement of the pipe pulls the slips against inclined seating surfaces to increase the grip on the [56] References Cited pipe. A power drive acting through the slip assembly is UNITED STATES PATENTS also provided for rotating the gripped pipe. l,8l7,467 8/1931 Thompson 24/263 DA UX 38 Claims, 12 Drawing Figures saw 73 I 0 424.1 g /a. J 721 2.7g"; 69

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A TTOENEYS Pmaminsirz wn SHEHBNG I TOR. COAL; A. 7a fiw A T TOENEYS 1 AUTOMATED PIPE-HANDLING SLIPS a, BACKGROUND OF THE INVENTION l. Field of the Invention In its broad aspects, the" present invention relates to means for gripping axially extending members and also to means for both gripping and rotating such members. In the particular application to be described, the pres-. ent invention relates to an automated slip assembly employed for gripping and rotating pipe. The invention may be employed as one or both of the gripping heads in a snubber, a back-up head in a rat-hole or as a rotary drilling apparatus. Other applications and uses of the assembly of the present invention will also suggest themselves to those skilled in the art.

2. Brief description of the Prior Art Prior art devices employed to grip and hold pipe and other cylindrical members are commonly referred to as "slips." Conventional slips are wedge shaped and are designed to be positioned between a conical seat and the pipe to be gripped Friction producing teeth formed along the internal surface of the slips engage the pipe and subsequent axial movement of the pipe with respect to the seat wedges the slips between the pipe and the seat to increase the slips gripping force. It will be appreciated that in slips of this conventional design, radial gripping forces exerted against the pipe are induced only by the axial movement of the pipe itself. If the slips do not take ai'i'initial grip on the pipe, the assembly is inoperative and the pipe will bepermitted to move axially.

Conventional slips are unsatisfactory for use where the pipe is to be rotated by motion imparted through rotation of the slips themselves. The need for such rotation is presented when drill pipe is suspended from the conical seat in a rotary table by means of conventional slips. Rotation of the suspended drill pipe may be required, for example, to preventthe pipe from sticking in the wellbore. If the'suspended pipe resists rotation,

the slips may spin out of the cone seat and release the I pipe. Such slips used as back-ups to stop rotation of a gripped pipe may also spin out of their seats.

SUMMARY or THE INVENTION The automated pipe handling slip assembly of the present invention is equipped with movable slip segments which may be driven radially into gripping engagement with the pipe without the need for any axial movement of the pipe. Wedging surfaces are also included in the assembly so that once axially directed forces in the pipe do occur, increased gripping forces are produced in the slips. In addition, the slip assembly of the present invention is equipped with a power drive to effect rotation of the gripped pipe through the assembly. Provision is also included for clockwise or counterclockwise rotation of the pipe with the resistance to rotation in either direction producing an increasingly greater gripping force. For this purpose, symmetrical camming surfaces are employed between relatively movable members in the assembly.

Positive setting and release of the slips is effected with a cam action employed between relatively movable parts in the slip assembly which move the slip members radially into andout of gripping engagement with the pipe without axial movement of the slips or pipe. Each of the slip members in the assembly includes rollers which bear against cainming surfaces formed on the relatively movable parts. In the preferred form of the assembly, a double taper seat is employed so that increased gripping forces are produced for movement of the pipe in either axial direction.

In a modified form of the present invention, the slips are moved radially by rotation of relatively movable parts in the slip assembly and a single powered drive is employed to engage the slips.

The foregoing features and advantages of the present invention as well as others will become more apparent from the following specification, claims and the related drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical elevation in quarter-section illustrating the preferred form of the pipe handling slips of the present invention in released position;

FIG. 2 is a view similar to FIG. 1 illustrating the slips in gripping engagement with a pipe;

FIG. 3 is a horizontal crosssection taken along the line 3-3 of FIG. 1; I

FIG. 4 is a horizontal cross-section taken along the line 4-4 of FIG. 2;

FIG. 5 is a horizontal cross-section taken along the line 5-5 of FIG. 2;

FIG. 6 is a partial horizontal cross-section taken along the line 6-6 of FIG. 1;

FIG. 7 is a vertical section illustrating a modified form of the pipe handling slips of the present invention in released position;

FIG. 8 is a view similar to FIG. 7 illustrating the slips in gripping engagement with a pipe;

FIG. 9 is a partial, reduced scale horizontal crosssection taken along the line 9-9 of FIG. 7;

FIG. 10 is a reduced scale horizontal cross-section 7 taken along the line 10-10 of FIG. 8;

FIG. 11 is a partial horizontal cross-section on an enlarged scale taken along the line 11-11 of FIG. 8; and

FIG. 12 is a partial plan view taken along the line 12-12 on a reduced scale.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred form of the automated pipe handling slip assembly of the present invention is indicated generally at 10 in FIG. 1. An elongate pipe P which is to be gripped and rotated extends concentrically through assembly 10. The assembly includes a fixed circular base plate 11 with cylinders 12 and 13 mounted at diametrically opposed positions along the edge of the plate. The plate 11 may be connected to other equipment (not illustrated) depending upon the intended use for the assembly. A motor 14 is also mounted on the fixed base plate 11 and is employed to rotate gripping components in the slip assembly 10 in a manner to be described. The motor 14 is preferably a hydraulic blies connected with the slip members -18, respectively.

Each of the gripping assemblies carried in the mounting and guide openings -23 is similar and may be understood from a description of the gripping assembly acting with the slip member 18. With reference to FIG. 1, the gripping assembly includes a radially movable seat member 24 which engages and supports the slip 18. The member 24 includes upper and lower oppositely inclined seating surfaces 24a and 24b, respectively which taper radially outwardly from their axial ends toward a common central line. Oppositely tapered upper and lower bearing surfaces 18a and 18b, respectively, engage the seating surfaces 240 and 24b, respectively. The slip member 18 is held in position against the seat member 24 by a headed bolt 25 which extends through the slip and threadedly engages the member 24. A Belville type spring washer 26 is positioned between the head of the bolt 25 and the slip 18 to urge the slip against the seat member 24 and to maintain the bearing surfaces on the slip properly positioned with respect to the seating surfaces on the seat. The innermost radial face of the slip 18 is equipped with a plurality of circumferentially extending, axially spaced friction producing teeth 18d which are employed to grip and hold the pipe P.

The seat member 24 carries rollers 27 and 28 held in position by a shaft 29 which extends axially through the member 24 and is held in position by rollers 30 and 31 attached to the ends of the shaft. Lubricating bores 32 and 33 extend axially and radially through the shaft 29 to convey oil or other lubricant to the rollers 27 and 28. Suitable screw type retaining members 34 and 35 are employed to retain the lubricant in the lubricating bores and to hold the rollers 30 and 31 on the ends of the shaft 29.

Referring jointly to FIGS. 1 and 3, a tubular housing 36 secured to the support structure 19 extends about a camming body C having four cam members 37-40 which in turn are carried externally of the gripping assemblies. The cam members 37-40 are spaced at 90 intervals and are connected at their upper and lower ends to annular webs 41 and 42, respectively, to form the cam body C. With reference to FIGS. 3 and 4, the cam members 37-40 carried in the body C are designed to be rotated relative to the gripping assemblies until the cams engage the rollers carried in each of the seat members thereby moving the gripping members radially inwardly. Each of the cams 37-40 tapers inwardly from each of its sides to a high cam center such as the center 400 on cam 40 so that two symmetrical cam faces, such as 40b and 40c are formed on each cam. Radial forces exerted by the cams against the gripping assemblies are increased as the rollers (corresponding to rollers 27 and 28) advance over the rotating cam surfaces corresponding to surface 40b, toward the high cam center. While the assembly 10 is designed for clockwise rotation of the pipe P, the cams 37-40 function in the same manner with counterclockwise rotation except that the rollers on the seat members bear against the second half of the cam surface corresponding to the surface 40c.

The upper web 41 of the cam body C is engaged by the roller 30 along a cam surface 41a formed on the web. The surface 41a is continuous and extends alternately from a radially outer position to a radially inner position. As may be seen in dotted line in FIG. 3, a correspondingly configured camming surface 42a formed in the lower web engages the lower roller 31. The camming surfaces 41a and 42a cooperate with the cam members 37-40 to permit inward radial movement of the four seat members as the cam body C is rotated in a clockwise direction from the position illustrated in FIG. 3. The surfaces 41a and 42a engage the rollers 30 and 31 to return the seat members to their outer radial position as the cam members 37-40 are rotated in a counterclockwise direction from the gripping position illustrated in FIG. 4 to the release position illustrated in FIG. 3. The design of the surfaces 41a and 42:: provide positive retraction of the gripping assemblies for rotation of the cam body C in either direction. As seen in FIG. 1, the cam members 37-40 in the body C are cut from a tubular form and the upper web 41 is secured to the members 37-40 by screws 43 which extend through the upper end of the form. The lower web 42 is welded to the base of the individual cam members 37-45. A brass spacing ring 44 is positioned between the web 41 and a centrally apertured housing top 45. The top 45 is welded to the housing 36 and a plurality of bolts 45a connect the top 45 to the mounting structure 19. A second brass spacing ring 46 is positioned between the web 42 and a holder 46a which acts as a mount for the inside race of a set of ball bearings 47. The rings 44 and 46 are employed to provide a tight fit between separate parts without binding movable components. The inside race of the ball bearings 46 is clamped between the holder 46a and an annular mount member 48 held to the structure 19 by a plurality of bolts such as the bolt 49. A second ball bearing assem bly 50 is positioned between the lower web 42 and the fixed base plate 11. The outside race of the bearings 50 is held in position by a ring clamp 51 which in turn is secured to the plate 11 by a plurality of bolts 52. The inside race of the bearings is clamped between a shoulder in the web 42 and a brass spacing ring 500. A liptype seat 53 extends from the ring clamp 51 to the lower web 42 to provide a sliding seal which shelters the ball bearings 50 from debris.

A gear housing 54 is secured to the base of the base plate by bolts 54a to protect a spur gear 55. The gear 55 is secured to the lower web 42 by means of a plurality of bolts 56. A lip seal 57 and an O-ring seal 58 form a sliding seal with the members 48 and 19, respectively to protect the ball bearings 47 from external materials. As best illustrated in FIG. 5, a drive gear 59 extending from the hydraulic motor 14 connects with the spur gear 55 to impart a rotary motion to the gear and the attached cam body C.

The housing 36 and attached mounting body 19 are rotated relative to the cam body C to cause gripping and release of the pipe P by axial movement of piston rods 61 and 62. The rods are attached to pistons, such as piston 63, which move throughthe cylinders 12 and 13. Piston 63 includes upper and lower end pieces 63a and 63b respectively, a central sleeve 630, a resilient O-ring seal 63d positioned between the sleeve 63c and the rod 61 and a resilient seal 63e carried about the sleeve 630. The pistons provide a continuous sliding seal with the internal wall of the cylinders 12 and 13. The piston 63 is held against a shoulder formed on the rod 61 by a suitable nut 64 threadedly engaged to the end of the rod 61. Packing 65 held in position by an end plate 66 secured to the upper end of the cylinder 12 by bolts 66a maintains a continuous sliding seal with the axially moving rod 61. Upper and lower inlet ports 67 and 68 are connected to fluid lines (not illustrated) which are employed to create a pressure differential acrossthe piston 63 to move the rod 61 in the desired axial direction. It will be appreciated that the rod and piston moving through the cylinder 13 is similar in construction and operation to that moving through the cylinder l2 and is also equipped with suitable fluid lines to provide the desired axial movement of the rod 62. It will also be appreciated that other axial drives, such as a rack and pinion powered through an electric motor or other suitable drive means may be employed.

The upper ends of the rods 61 and 62 are connected to ears 69a .and 69b, respectively, extending radially from a collar 69. Threaded bolts 61a and 62a are employed to hold the collar against suitable shoulders formed on the rods 61 and 62, respectively. Suitable roller bearings 70 extend from the collar 69 into a circumferential groove 71 formed between an annular ring 72 and a cap plate 73. The plate 73 is held in position against the upper end of the ring 72 by a plurality of screws 74. The base of ring 72 is welded to a tubular overbody 75 which extends downwardly over the tubular housing 36.

The lower end of the overbody 75 is equipped with cam rollers 76 and 77 carried at diametrically opposite positions on the body 75. The rollers 76 and 77 are similar in construction, and with reference to FIG. 6 illustrating the roller 77, include a headed shaft 78 supports dual rollers 79a and 79b. The roller 79a is engaged within an inclined cam slot 80 formed in the wall of the housing 36 and the roller 7% is engaged in a cam groove 81 formed in the cam member 40. Referring to FIGS. 1 and 4, the roller 76 is illustrated in position within an inclined cam slot 82 formed in the housing 36 and an inclined cam groove 82a formed in the cam member 38. The housing slots 80 and 82 are similar but incline in different directions. The cam member grooves 81 and 820 are also similar in construction to each other but are oppositely inclined. In addition, the slot 80 is oppositely inclined with respect to the groove 81 and the slot 82 is oppositely inclined with respect to groove 82a.

The assembly 10 as illustrated in FIGS. 1-6 is designed for right-hand rotation and the slots 80 and 82 form a cooperating pair for engaging the rollers 76 and 77 to produce rotational movement of the cam body C with axial movement of the rollers 76 and 77. As will be seen, axial movement of the rollers 76 and 77 rotates the housing 36 and cam body C in opposite directions relative to each other to either engage or release the gripping members. The cam grooves in cam members 37-40 have a greater angle of inclination than that of the slots in housing 36 so that axial movement of the rollers 76 and 77 causes the cam body C to rotate faster than the housing 36. In addition, a relatively large axial movement of rollers 76 and 77 is required to produce a relatively small rotational movement of the cam members 37-40 thereby providing a mechanical advantage in the linear to rotary motion conversion. Slots 80' and 82' spaced at 180 intervals form a second slot pair in the housing 36. A second set of cam grooves 81' and 82a is formed in cam members 39 and 37, respectively to form a second groove pair. Slot 80 and groove 81 are designed to receive roller 77, and slot 82' and groove 82a are adapted to receive roller 76 for rotation of the pipe P in a counterclockwise direction.

OPERATION OF THE SLIP ASSEMBLY With components of the assembly 10 in-the relative positions illustrated in FIG. 1, the pipe P is passed through the center ofthe assembly as illustrated. The gripping assemblies are engaged against the pipe P by applying fluid pressure through the upper ports (such as the port 67) in the cylinders 12 and 13 causing the pistons and attached rods 61 and 62 to be moved linearly downwardly through the cylinders. This downward motion is transmitted from the connecting rods to the collar 69, through the bearings to the overbody 75. As the overbody moves downwardly, the roller 77 bears downwardly against the slot 80 and groove 81 and the roller 76 bears downwardly against the slot 82 and groove 82a causing the housing 36 to rotate in a counterclockwise direction as viewed in FIG. 3) and the cam members 37-40 to rotate in a clockwise direction. Clockwise rotation of the cam body C with respect to the housing 36 and mounting structure 19 moves the cam members 37-40 from the position illustrated in FIG. 3 to that illustrated in FIG. 4 where the gripping assemblies are forced into tight gripping connection with the pipe P. With the pipe gripped, the motor 14 may be energized causing rotation of the drive gear 59 which in turn rotates the spur gear 55 and the attached camming body C. As the motor causes rotation of the camming body C in a clockwise direction (as viewed in FIG. 3), the wedging engagement between the cam members 37-40 imparts rotary motion to the gripping assemblies which in turn cause rotation of the pipe P. Thus, rotation of the camming body C causes rotation of the support structure 19 and housing 36 after the gripping assemblies are locked against the pipe P. As the overbody is rotated through the collar 69, the roller bearings 70 and ball bearings 50 permit free rotation of the overbody 75, cam body C and mounting structure 19 with respect to the fixed base plate-11, hydraulic motor 14 and cylinders 12 and 13. It will be appreciated that resistance to rotation by the pipe P tends to force the slip rollers (such as rollers 27 and 28) closer to the high center (such as the center 40a) of the camming surfaces on the cam body C which in turn increases the radially directed gripping forces exerted against the pipe P. Resistance to clockwise rotation of the pipe P also tends to move the rollers 76 and 77 downwardly through slots 80 and 82 formed in the housing 36 to further increase the gripping force exerted by the slips against the pipe P.

When the'pipe is to be released, the motor 14 is deenergized and the pistons in the cylinders 12 and 13 are driven upwardly by exerting fluid pressure through the lower ports (such as port 68 in the cylinder 12). Upward movement of the piston rods 61 and 62 raises the overbody 75 which in turn raises the rollers 76 and 77 through the housing slots and cam grooves to rotate the cam body C back to the position illustrated in FIG. 3. As explained previously, camming surfaces 41a and 42a engage the rollers 30 and 31, respectively, during this reverse rotation to positively withdraw the gripping assemblies from engagement with the pipe.

If the pipe is to be rotated in a counterclockwise direction, the roller 76 is engaged with the slot 82' and groove 82a and the roller 77 is engaged with the slot 80 and grooves 81 Subsequent downward movement of the rollers 76 and 77 through the slots and grooves causes the cam body C to rotate in a counterclockwise direction with respect to the sport structure 19 and cam body C. Corresponding operation of the assembly for counterclockwise rotation of the pipe P is analogous to that described for clockwise rotation.

MODIFIED ASSEMBLY A modified form of the invention is indicated generally at 110 in FIGS. 7 and 8. The assembly 110 is adapted to grip and rotate a pipe P which extends through the center of the assembly. A primary distinction between the assembly 110 and the previously described assembly 10 is that assembly 110 effects radial gripping and release movement of the slips by rotary movement alone.

The assembly 110 includes a relatively fixed outer housing 111 formed from a centrally apertured base plate 1110, a tubular housing section 11117 and a centrally apertured top plate 111c. The various housing components are held together by suitable bolts 111d. A central tubular camming section 112 is welded to the base plate 111a and extends axially upwardly through the assembly 110. Hydraulic motors 113 and 114 are mounted to the assembly 110 from the housing plate l11c by screws 115. The motors 113 and 114 are similar and are of a conventional design. If desired, the function of the hydraulic motors may be provided with other suitable powering means. With specific reference to the motor 113, a drive shaft 115 extending from the motor is secured to a small drive gear 116. A key 117 prevents relative rotation between the shaft 115 and the gear 116. The smooth cylindrical base of the gear 116 is set within a brass bushing and the cylindrical upper end of the gear is mounted in a needle bearing assembly 119. Teeth 116a extending from the central body of the gear 116 engage teeth 120a (FIG. 10) on a ring gear 120. The ring gear 120 is connected to the outer rim of a centrally apertured circular plate 121 by screws 122. The plate 121 connects to a slip mounting structure 123 by screws 124 extending from the plate through a spacing ring 125 and into the structure 123.

Referring jointly to FIGS. 7, 9 and 11, four gripping assemblies 126-129 are respectively mounted for radial movement through openings 130-133 formed in the mounting structure 123. The gripping assemblies 126-129 are similar and will be described with specific reference to the assembly 126 which includes a wedge shaped slip segment 134 carried by an inclined tongue and groove connection in a seat segment 135. The tongue and groove are wedge shaped to permit sliding movement between the seat and slip members while preventing separation of the two components. The radially inner face of the slip 134 carries dies 136 equipped with friction producing faces. The dies are maintained in position against a lower shoulder 136 formed adjacent the base of the slip member 135 and a retaining bolt 138 threadedly engaged to the slip member 135 at the top of each of the dies. The dies 136 are preferably tapered and are received in a tapered slot formed in the slips 134 so that removal and placement of the dies requires removal of the bolt 138 and axial sliding of the dies through the receiving bores. A

resilient leaf spring 139 mounted to the slip seat member by a bolt 140 engages the slip 134 and resiliently maintains the slip at the upper axial position in the opening 130.

Each of the seat members is equipped with an axially extending shaft 140 which supports upper and lower rollers 141 and 142, respectively. The shaft 140 carries smaller rollers 143 and 144 at its upper and lower ends respectively, and snap rings 145 and 146 hold the rollers and shaft in position on the seat member 135.

The internal walls of the tubular cam body 112 are provided with four symmetrical camming surfaces 147-150. The cam surfaces extend radially outwardly from two innermost positions represented for example at 1470 and 147b (FIG. 9) to a central, radially outermost position 147C. As will be seen, rotation of the camming body 112 relative to the gripping assemblies 126-129 moves the assemblies into gripping engagement with the pipe P. Upper and lower cam plates 151 and 152 are rigidly connected to the upper and lower ends of the cam body 112. The upper cam plate is equipped with a camming surface 153 and the lower plate is equipped with a similar camming surface 154. The surfaces 153 and 154 engage the small rollers corresponding to the rollers 143 and 144 and function to move the gripping assemblies to their radially outer position when the cam body 112 and attached cam plates 151 and 152 are rotated relative to the mounting structure 123.

The circular plate 121 is mounted within a large brass ring 155 set within the housing top lllc. The ring 155 mounts the plate 121 for rotation with respect to the housing 111. An indexing plate 156 is bolted to the plate 121 by screws 157. The plate 156 is equipped with a recess 158 having ends 1580 and 158b. When the large seat rollers (such as rollers 141 and 142) are opposite the radially outermost cam positions (such as 147), the assembly is in neutral and the recess end 1580 engages the head of an indexing bolt 159 which is set in the housing top 1116. The bolt 159 is positioned for clockwise rotation of the plate 121 and attached mounting structure 123 relative to the cam body 112. Where counterclockwise rotation is to be employed, the bolt 159 is set in a threaded hole 160. When the shoulder 158b engages the bolt 159 in the latter position, the assembly is again in neutral.

OPERATION OF THE MODIFIED ASSEMBLY With the components in the position illustrated in FIG. 7, the motors 113, 114 are energized to impart a rotary movement to the ring gear 120. This movement is transmitted to the plate 121 and the attached mounting structure 123. Rotation of the mounting structure 123 relative to the cam body 112 advances the large seat rollers (such as rollers 141 and 142) along the cam surfaces 147-150 which in turn moves the gripping assemblies 126-129 radially inwardly into gripping engagement with the pipe P. Once the pipe P has been gripped, the wedging engagement prevents further rotation of the cam body and the motors 113 and 114 stall. With the slips engaging the pipe P, forces tending to rotate the pipe P in a counterclockwise direction (as viewed in FIG. 9) cause the larger rollers carried in the seat members to attempt to advance up the cam surfaces which in turn increases the slips gripping engagement with the pipe. The assembling functions in an analogous way to provide a back up for clockwise rotation of the pipe P. It will be appreciated that the grip exerted by the assembly 110 in sufficient to resist pipe rotation in either direction but functions to increase the gripping force where the rotation tends to advance the large seat rollers toward the high centers of the cam surfaces.

With the gripping assemblies engaging the pipe as illustrated in FIG. 8, subsequent downward axial movement of the pipe P tends to wedge the slip members between the pipe and the inclined bearing surfaces formed on the seating members to further increase the gripping force exerted against the pipe. The leaf springs 139 retains the slips at their upper axial position so that clearance exists below the slips when they initially engage the pipe P. Subsequent down forces produce a slight downward movement of the slips relative to the seat members to produce a wedging action which increases the grip on the pipe. When the pipe is to be released, the motors are reversed to bring the gripping assemblies and cam surfaces 147-150 back into the respective positions illustrated in FIG. 9. The indexing mechanism associated with the plate 156 ensures complete retraction of the slips and movement of the large seat rollers into the positions illustrated in FIG. 9.

It will be appreciated that while only a single tapered surface has been illustrated for the modified assembly 110, the slip and seat arrangement may be modified to provide dual tapered seating and bearing surfaces which would provide increased gripping for axial movement of the pipe in either direction.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and vari ous changes in the size, shape and materials as well as in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. An automated apparatus for handling an axially extending cylindrical member comprising:

a. friction means for engaging and gripping said member;

b. mounting means for mounting said friction means for linear radial movement with respect to said member while holding said friction means fixed axially with respect to said member;

0. powered drive means for moving said friction means radially through said mounting means into gripping engagement with said member; and

d. axial wedging means included with said mounting means for increasing the radially directed gripping force between said friction means and said cylindrical member as the axially directed forces in said member increase.

2. An apparatus as defined in claim 1 further including rotating means for rotating said friction means and mounting means whereby said cylindrical member is rotated when gripped by said friction means.

3. An apparatus as defined in claim 2 further including rotary wedging means connected with said drive means for increasing the radially directed gripping force between said friction means and said cylindrical member as the forces opposing rotation of said member increase.

4. An apparatus as defined in claim 1 wherein:

a. said axial wedging means include radially movable seat means having seating surfaces which are axially inclined with respect to the axis of said cylindrical member; and

b. said friction means include slip means having inclined bearing surfaces adapted to engage and slide against said inclined seating surfaces whereby axial movement of said slip means with respect to said seat means moves said slip means radially to increase theradially directed gripping forces exerted against said cylindrical member.

5. An apparatus as defined in claim 4 further including rotating means for rotating said friction means and mounting means whereby said cylindrical member is rotated when gripped by said friction means.

6. An apparatus as defined in claim 5 further including rotary wedging means connected with said drive means for increasing the radially directed gripping force between said friction means and said cylindrical member as the forces opposing rotation of said member increase.

7. An apparatus as defined in claim 4 wherein said powered drive means includes camming means disposed radially externally of said radially movable seating surfaces for moving said seat means and slip means radially inwardly as said camming means is rotated relative to said slip means.

8. An apparatus as defined in claim 7 further including roller means connected with said seat means and adapted to roll against said camming means for moving said seat means and slip means radially inwardly as said camming means is rotated relative to said slip means.

9. An apparatus as defined in claim 7 further includ ing rotating means for rotating said friction means and mounting means whereby said cylindrical member is rotated when gripped by said friction means.

10. An apparatus as defined in claim 9 further including rotary wedging means connected with said drive means for increasing the radially directed gripping force between said friction means and said cylindrical member as the forces opposing rotation of said member increase.

11. An apparatus as defined in claim 7 wherein said camming means includes cam surfaces carried on a cam body which is rotated by a powered rotating means whereby rotation of said cam body moves said cam surfaces relative to said slip means to move said friction means into gripping engagement with said cylindrical member.

12. An apparatus as defined in claim 11 further including roller means connected with said seat means and adapted to roll against said camming means for moving said seat means and slip means radially inwardly as said camming means is rotated relative to said slip means.

13. An apparatus as defined in claim 11 wherein said cam surfaces include a plurality of circumferentially spaced cam areas formed on the internal wall of a tubular body each of which areas is developed radially from said point toward the central axis of said apparatus along the circumferential development of said area whereby said slip means are in a radially retracted position when said seat means engage said point and are moved radially inwardly as said area is rotated with respect to said point.

14. An apparatus as defined in claim 13 wherein said cam areas are symmetrical about said point whereby rotation of said areas in either direction relative to said slip means moves said slip means toward a radially inner position.

15. An apparatus as defined in claim 14 wherein said powered rotating means includes a motor for rotating said tubular body.

16. An apparatus as defined in claim 15 wherein said motor is reversible.

17. An apparatus as defined in claim 11 further including means for retracting said friction means radially through said mounting means out of engagement with said member.

18. An apparatus as defined in claim 11 further including wedging means connected with said drive means for increasing the radially directed gripping force between said friction means and said cylindrical member as said cylindrical member is urged rotatably with respect to said mounting means.

19. An apparatus as defined in claim 1 wherein said powered drive means includes camming means rotatably movable with respect to said friction means for moving said friction means radially as said camming means is rotated with respect to said friction means.

20. An apparatus as defined in claim 1 further including wedging means connected with said drive means for increasing the radially directed gripping force between said friction means and said cylindrical member as said cylindrical member is urged rotatably with respect to said mounting means.

21. Automated pipe handling slips comprising:

a. a plurality of gripping means having tapered bearing surfaces on their radially outer ends and friction producing pipe engaging means on their radially inner ends;

b. bearing means having tapered bearing surfaces adapted to engage said bearing surfaces on said gripping means; and

c. powered drive means for linearly driving both said gripping means and said bearing means radially into gripping engagement with a pipe whereby axial movement of said pipe, when engaged by said pipe engaging means, wedges said gripping means between said pipe and said bearing means to increase the gripping force exerted by said slips on said pipe, said powered drive means including means for positively driving said gripping means radially away from said pipe.

22. Automated pipe handling slips as defined in claim 21 further including rotating means for rotating said gripping means and said bearing means whereby said pipe may be rotated when gripped by said pipe engaging means.

23. Automated pipe handling slips as defined in claim 22 further including rotary wedging means for increasing the gripping force exerted against said pipe as the forces resisting rotation of said pipe increase.

24. An automated apparatus for handling an axially extending cylindrical member comprising:

a. friction means for engaging and gripping said member;

b. mounting means for mounting said friction means for radial movement with respect to said member while holding said friction means fixed axially with respect to said member;

c. powered drive means for moving said friction means radially through said mounting means into gripping engagement with said member;

d. axial wedging means included with said mounting means for increasing the radially directed gripping force between said friction means and said cylindrical member as the axially directed forces in said member increase;

e. radially movable seat means included with said axial wedging means, said seat means having oppositely tapered upper and lower seating surfaces which are axially inclined with respect to the axis of said cylindrical member; and

f. slip means included with said friction means, said slip means having oppositely inclined upper and lower bearing surfaces adapted to engage and slide against said upper and lower seating surfaces whereby upward or downward axial movement of said slip means with respect to said seat means moves said slip means radially to increase the radially directed gripping forces exerted against said cylindrical member.

25. An apparatus as described in claim 24 further including rotating means for rotating said friction means and mounting means whereby said cylindrical member is rotated when gripped by said friction means.

26. An apparatus as defined in claim 25 further including rotatary wedging means connected with said drive means for increasing the radially directed gripping force between said friction means and said cylindrical member as the forces opposing rotation of said member increase.

27. An automated apparatus for handling an axially extending cylindrical member comprising:

a. friction means for engaging and gripping said member;

b. mounting means for mounting said friction means for radial movement with respect to said member while holding said friction means fixed axially with respect to said member;

c. powered drive means for moving said friction means radially through said mounting means into gripping engagement with said member;

d. axial wedging means included with said mounting means for increasing the radially directed gripping force between said friction means and said cylindrical member as the axially directed forces in said member increase;

e. radially movable seat means included with said axial wedging means, said seat means having seating surfaces which are axially inclined with respect to the axis of said cylindrical member; slip means included with said friction means, said slip means having inclined bearing surfaces adapted to engage and slide against said inclined seating surfaces whereby axial movement of said slip means with respect to said seat means moves said slip means radially to increase the radially directed gripping forces exerted against said cylindrical member;

g. camming means included with said powered drive means, said camming means disposed radially externally of said radially movable seating surfaces for moving said seat means and slip means radially inwardly as said camming means is rotated relative to said slip means;

h. a cam body means included with said camming means;

i. motion converting means connected with said cam body means for converting linear motion to rotary motion; and

j. linear motion producing means in said power drive means connected to said motion converting means for driving said converting means linearly to rotate said cam body means relative to said friction means.

28. An apparatus as defined in claim 27 further including rotating means for rotating said friction means and mounting means whereby said cylindrical member is rotated continuously after being gripped by said friction means.

29. An apparatus as defined in claim 28 wherein:

a. said cam body means includes upper and lower, horizontally disposed camming plates connected to axially extending camming members;

b. said cam body means is connected with motion converting means having oppositely inclined engagement means carried by a tubular body means and said camming members and adapted to engage a linear drive assembly in said linear motion producing means whereby axial motion of said linear drive assembly rotates said tubular body means and said cam body means in opposite directions; and

c. said linear drive assembly includes fluid driven piston means.

30. An apparatus as defined in claim 29 wherein:

a. said tubular body means includes a first pair of diametrically opposed, oppositely inclined slot means formed through the wall of said tubular body means and said camming members include a first pair of diametrically opposed, oppositely inclined groove means to form said inclined engagement means;

b. said linear drive assembly includes a tubularouter body carrying roller members adapted to roll in said first pairs of inclined slot and groove means; and

c. said fluid driven piston means include fluid driven piston and cylinder means having axially movable connecting rod means engaging said tubular outer body whereby linear movement of said pistons and outer body is transmitted through said roller members to said inclined engagement means for rotating said camming body relative to said friction producing means.

31. An apparatus as defined in claim 30 further including roller means connected with said seat means and adapted to roll against said cam body means for moving said seat means and slip means radially inwardly and outwardly as said camming means is rotated relatively to said slip means.

32. An apparatus as defined in claim 31 wherein:

a. said rotating means includes an hydraulic motor;

and

b. the engagement between said connecting rod means and said tubular outer body permits continuous rotation of said outer body with respect to said connecting rod means.

33. An apparatus as defined in claim 32 wherein:

a. said seat means include oppositely tapered upper and lower seating surfaces; and

b. said slip means include oppositely inclined upper and lower bearing surfaces adapted to engage and slide against said upper or lower seating surfaces respectively whereby upward or downward axial' movement of said slip means with respect to said seat means moves said slip means radially to increase the radially directed forces exerted against said cylindrical member.

34. An apparatus as defined in claim 33 wherein said slip and seat means include four equally spaced slip and seat means sets adapted to move radially to converge on said cylindrical member at substantially the same axial location.

35. An apparatus as defined in claim 34 further includng second pairs of diametrically opposed oppositely inclined slot means and groove means circumferentially spaced from said first pairs of slot and groove means and oppositely inclined with respect thereto whereby said roller members may be mounted in said first pair of slot and groove means for increasing the gripping force of said friction means with clockwise rotation of said powered rotating means and may be mounted in said second pair of slot and groove means for increasing the gripping force of said friction means with counterclockwise rotation of said powered rotating means.

36. An automated apparatus for handling an axially extending cylindrical member comprising:

a. friction means for engaging and gripping said member;

b. mounting means for mounting said friction means for radial movement with respect to said member while holding said friction means fixed axially with respect to said member;

c. powered drive means for moving said friction means radially through said mounting means into gripping engagement with said member;

d. axial wedging means included with said mounting means for increasing the radially directed gripping force between said friction means and said cylindrical member as the axially directed forces in said member increase; and

e. means for retracting said friction means radially through said mounting means out of engagement with said member.

37. An apparatus as defined in claim 36 further including indexing means for automatically returning said friction means to their outermost radial positions following release of said member.

38. An apparatus as defined in claim 36 further including indexing means for automatically returning said friction means to their outermost radial position following release of said member.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,760 62 I x V Dated SeQtembeI' 25 1973 Inventorts) (Ii C61 0 C. Brown I I I It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, Line 63: change "ripping" to -gripping--.

Column 6, lih'e 22: after "direction" insert Column 9 line M7: after "for" insert -linear-;

Si gnedand vsealed this 5th day of March 1974 (SEAL) Att'est: EDWARD M.FLETCHEHR,JR.' C M H L D Attestltng oflflceyr Commissioner of Patents USCOMM-DC 60376-P69 #1 us. eovzmmsm' vnm'rme OFFICE: 1909 o-sss-su, {7

F ORM PO-1050 (10-69)

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4269277 *Jul 2, 1979May 26, 1981Brown Oil Tools, Inc.Power slip assembly
US4576254 *Feb 6, 1984Mar 18, 1986Otis Engineering CorporationHydraulically actuated slip assembly
US4756538 *Mar 25, 1986Jul 12, 1988The Science and Technic Department of Dagang Petroleum AdministrationDevice for clamping drill pipe and the like in mouse hole pipe
US5027926 *Feb 26, 1990Jul 2, 1991Otis Engineering CorporationSlip assembly
US5456325 *Apr 19, 1994Oct 10, 1995Southwest Research InstituteMethod and apparatus for driving a probe into the earth
US6199641 *Sep 21, 1998Mar 13, 2001Tesco CorporationPipe gripping device
US6948904Jun 7, 2002Sep 27, 2005Jack BunnHydraulically actuated casing slip lifter with hinged wrap arm assembly
US7293618Mar 12, 2004Nov 13, 2007National-Oilwell, L.P.Power slip for drillpipe
US7395855Apr 1, 2003Jul 8, 2008Coupler Developments LimitedRadially moving slips
US20050199397 *Mar 12, 2004Sep 15, 2005Belik Jaroslav V.Power slip for drillpipe
EP1577487A1 *Mar 11, 2005Sep 21, 2005National Oilwell, Inc.Power slip for drill pipe
WO2003087528A1 *Apr 1, 2003Oct 23, 2003Ayling Laurence JohnImproved slips
Classifications
U.S. Classification81/57.18, 81/57.21, 279/4.6
International ClassificationE21B19/16, E21B19/00, E21B19/07
Cooperative ClassificationE21B19/16, E21B19/07
European ClassificationE21B19/16, E21B19/07
Legal Events
DateCodeEventDescription
Apr 5, 1982ASAssignment
Owner name: HUGHES TOOL COMPANY A CORP. OF DE
Free format text: MERGER;ASSIGNOR:BROWN OIL TOOLS, INC. A TX CORP.;REEL/FRAME:003967/0348
Effective date: 19811214