Well slip assembly

Claim 2

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection attaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, and a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said second connection including means forming a generally axially extending guideway in said slip bowl structure which converges progressively toward said axis as it advances axially, and interfitting means carried by said one slip structure and projecting into and movable along said guideway, said guideway having a first portion extending at essentially a uniform angle to said axis, and having an end portion curving progressively away from the axis.

Claim 3

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection attaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, and a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said second connection including means forming a generally axially extending guideway in said slip bowl structure which converges toward said axis, and interfitting means carried by said one slip structure and projecting into and retained within and movable along said guideway, said interfitting means comprising a lug projecting generally radially outwardly from said one slip structure into said guideway, and a pin extending through and retained by said lug, said guideway having two opposite side walls containing two undercut grooves, and guidably receiving opoosite ends of said pin.

Claim 4

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection attaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, and a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said second connection including means forming a generally axially extending guideway in said slip bowl structure which converges toward said axis, and interfitting means carried by said one slip structure and projecting into and retained within and movable along said guideway, said interfitting means comprising a lug projecting generally radially outwardly from said one slip structure into said guideway, and a pin extending through and retained by said lug, said guideway having two opposite side walls containing two undercut grooves, and guidably receiving opoosite ends of said pin.

Claim 5

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection aTtaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, and a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said second connection including means forming a guideway in said bowl structure, and two lugs projecting from said one slip structure and from an adjacent second slip structure into said guideway and both guided for movement therealong, said lugs being free for limited movement relative to one another within said guideway.

Claim 6

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection aTtaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, and a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said second connection including means forming a guideway in said bowl structure, and two lugs projecting from said one slip structure and from an adjacent second slip structure into said guideway and both guided for movement therealong, said lugs being free for limited movement relative to one another within said guideway.

Claim 7

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection attaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, and a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said first connection comprising a swinging arm attached to said bowl structure for swinging movement, two adjacent lugs formed on said one slip structure and on an adjacent second slip structure, and means connecting said lugs essentially pivotally to said arm for actuation thereby but allowing limited relative adjusting movement of the two slip structures.

Claim 8

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection attaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, and a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said first connection comprising a swinging arm attached to said bowl structure for swinging movement, two adjacent lugs formed on said one slip structure and on an adjacent second slip structure, and means connecting said lugs essentially pivotally to said arm for actuation thereby but allowing limited relative adjusting movement of the two slip structures.

Claim 9

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection attaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said structures having engaging tapering camming surfaces, said first connection including an arm mounted to said bowl structure for swinging movement relative thereto and connected essentially pivotally to said one slip structure and to an adjacent second slip structure to actuate them essentially in unison but enabling limited relative movement of the two slip structures, said second connection including means forming a guideway in said bowl structure recessed outwardly beyond said tapering surfaces and following essentially the taper thereof, and lugs on said one slip structure and said second slip structure projecting into and movably guided by said guideway and free for limited relative movement, and powered means for actuating said swinging arm to move said one slip structure and said second slip structure generally axially.

Claim 10

A slip assembly for gripping a tubular well string, extending along an axis, comprising a slip bowl structure, a plurality of slip structures engaging said bowl structure in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof, a first connection attaching one of said slip structures to said bowl structure movably at a first location for generally axial relative movement between an active string gripping position and a retracted position, a second connection attaching the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location and in a relation positively controlling its orientation during shifting movement by the movable attachment of the slip structure to the bowl at said two spaced locations, said structures having engaging tapering camming surfaces, said first connection including an arm mounted to said bowl structure for swinging movement relative thereto and connected essentially pivotally to said one slip structure and to an adjacent second slip structure to actuate them essentially in unison but enabling limited relative movement of the two slip structures, said second connection including means forming a guideway in said bowl structure recessed outwardly beyond said tapering surfaces and following essentially the taper thereof, and lugs on said one slip structure and said second slip structure projecting into and movably guided by said guideway and free for limited relative movement, and powered means for actuating said swinging arm to move said one slip structure and said second slip structure generally axially.

Claim 11

A slip assembly as recited in claim 5, including means forming a second pair of said first and second connections essentially diametrically opposite said first pair of connections for movably mounting a second pair of said slip structures while allowing limited relative movement thereof, said second pair of connections including a secOnd of said swinging arms and a second guideway; there being linkage operatively connecting said two swinging arms together for pivotal movement in opposite directions to actuate their respective slip structures essentially in unison.

Claim 12

A slip assembly as recited in claim 6, in which each of said second connections includes a pin in one of said guideways extending through apertures in said lugs of two associated slip structures with some looseness and having opposite ends guidably received within two parallel undercut guide grooves formed in two opposite side walls of the guideway.

Claim 13

A slip assembly as recited in claim 7, in which said guideways have ends which curve progressively away from said axis and open essentially radially outwardly away from the axis.

Claim 14

A slip assembly for gripping a tubular well string, extending along an axis; comprising a slip bowl structure, a plurality of slip structures; said bowl structure and said slip structures having tapering surfaces engaging in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof; an arm mounted for swinging movement relative to said bowl structure and connected to a first portion of one of said slip structures at a first location in a relation causing said portion, upon swinging movement of the arm, to move between an active string gripping position and a retracted position; a connection attaching a second portion of the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location; said connection including a guide structure carried by said bowl structure, and co-acting means carried by said one slip structure and interfitting with said guide structure for guided movement generally axially therealong; said guide structure having a first portion directing said co-acting means along a path disposed at essentially a uniform angularity with respect to said axis, and having a second portion therebeyond directing said co-acting means along a path which curves progressively away from said axis at an increasing angularity with respect thereto.

Claim 15

A slip assembly for gripping a tubular well string, extending along an axis; comprising a slip bowl structure, a plurality of slip structures; said bowl structure and said slip structures having tapering surfaces engaging in a camming relation acting to cam the slip structures radially inwardly upon axial movement thereof; an arm mounted for swinging movement relative to said bowl structure and connected to a first portion of one of said slip structures at a first location in a relation causing said portion, upon swinging movement of the arm, to move between an active string gripping position and a retracted position; a connection attaching a second portion of the same slip structure to said bowl structure movably at a second location spaced generally axially from said first location; said connection including a guide structure carried by said bowl structure, and co-acting means carried by said one slip structure and interfitting with said guide structure for guided movement generally axially therealong; said guide structure having a first portion directing said co-acting means along a path disposed at essentially a uniform angularity with respect to said axis, and having a second portion therebeyond directing said co-acting means along a path which curves progressively away from said axis at an increasing angularity with respect thereto.

Claim 16

A slip assembly as recited in claim 9, including powered means for actuating said slip structures generally axially between active string gripping positions and retracted positions.

Claim 17

A slip assembly as recited in claim 10, in which said powered means comprise a fluid actuated piston and cylinder assembly.

Claim 18

A slip assembly as recited in claim 9, in which said guide structure is a guideway formed in said slip bowl structure and recessed radially outwardly thereinto beyond said camming surfaces, said coacting means including a guide unit carried by said one slip structure and projecting outwardly therefrom past the diameter of said camming surfaces and into said guideway and guided thereby for movement along the guideway first at said uniform angularity to the axis and then at said increasing angularity.

Claim 19

A slip assembly as recited in claim 9, including means attaching a second of said slip structures to said one slip structure at both of said first and second locations for movement with said one slip structure between said positions but allowing limited relative adjusting movement of the two slip structures.