Well tool anchoring apparatus

Claim 2

Means for anchoring a well tool in a well bore including a slip element having oppositely disposed head portions joined together by a central connecting portion, each head portion having a toothed outer peripheral surface and an inclined inner surface, each head portion further having a retractor surface that is inclined at an angle that is substantially greater than the angle of inclination of said inner surface but less than 90*.

Claim 3

The anchoring means of claim 1 wherein each head portion is wider than said connecting portion to provide said retractor surface to the side thereof.

Claim 4

The anchoring means of claim 2 wherein said slip element further includes a recess extending inwardly of said connection portion, said recess being arranged and adapted to receive a slip element retaining member.

Claim 5

The anchoring means of claim 1 wherein said angle of inclination of said retractor surface is about 60* and the angle of inclination of said inner surface is about 20*.

Claim 6

Apparatus for anchoring a well tool against longitudinal movement in a well bore, comprising: slip and expander means movable longitudinally relative to each other to cause lateral movement of said slip means, said slip and expander means having companion inclined expander surfaces to cause lateral outward movement and companion inclined retractor surfaces to cause lateral inward movement, said retractor surfaces being inclined at an angle that is substantially greater than the angle of inclination of said expander surfaces but less than 90*.

Claim 7

Apparatus for anchoring a well tool against longitudinal movement in a well bore, comprising: slip and expander means movable longitudinally relative to each other to cause lateral movement of said slip means, said slip and expander means having companion inclined expander surfaces to cause lateral outward movement and companion inclined retractor surfaces to cause lateral inward movement, said retractor surfaces being inclined at an angle that is substantially greater than the angle of inclination of said expander surfaces but less than 90*.

Claim 8

The apparatus of claim 5 wherein said slip means has a head portion that is generally wedge shaped in such a manner that the expander surface thereof faces inwardly and the retractor surface thereof faces outwardly, said expander means having oppositely facing companion surfaces.

Claim 9

The apparatus of claim 5 wherein said slip means has a head portion that is generally wedge shaped in such a manner as to provide a rearwardly facing expander surface and forwardly facing retractor surfaces to either side thereof, said expander means having oppositely facing companion surfaces.

Claim 10

The apparatus of claim 7 wherein said expander means comprises a generally tubular body having a recess therein that is defined in part by said inclined expander surface, said body having retractor dogs to either side of said expander surface with wall portions providing inwardly facing retractor surfaces.

Claim 11

Apparatus for anchoring a well tool against longitudinal movement in a well bore, comprising: upper and lower expander means movable relatively toward each other and away from each other; normally retracted slip means disposed between and engaging said upper and lower expander means and adapted to be shifted outwardly in response to movement of said expander means toward each other and to be shifted inwardly in response to movement of said expander means away from each other; each slip means including an upper head portion coacting with said upper expander means and a lower head portion coacting with said lower expander means, said head portions being joined together by a connecting portion to provide a unitary construction; each head portion having an inner inclined surface and outer inclined surfaces, said inner inclined surface being slidably engaged by a companion outer surface on a respective expander means, said outer inclined surfaces being adapted to coact with companion inner surfaces on a respective expander means to cause retraction of said slip means; the angle of inclination with respect to vertical of said outer inclined surfaces being greater than the angle of inclination of said inner inclined surface.

Claim 12

Apparatus for anchoring a well tool against longitudinal movement in a well bore, comprising: upper and lower expander means movable relatively toward each other and away from each other; normally retracted slip means disposed between and engaging said upper and lower expander means and adapted to be shifted outwardly in response to movement of said expander means toward each other and to be shifted inwardly in response to movement of said expander means away from each other; each slip means including an upper head portion coacting with said upper expander means and a lower head portion coacting with said lower expander means, said head portions being joined together by a connecting portion to provide a unitary construction; each head portion having an inner inclined surface and outer inclined surfaces, said inner inclined surface being slidably engaged by a companion outer surface on a respective expander means, said outer inclined surfaces being adapted to coact with companion inner surfaces on a respective expander means to cause retraction of said slip means; the angle of inclination with respect to vertical of said outer inclined surfaces being greater than the angle of inclination of said inner inclined surface.

Claim 13

The apparatus of claim 9 wherein said head portions are wider than said connecting portion to provide transverse sections to either side thereof, said transverse sections being defined in part by said outer inclined surfaces.

Claim 14

The apparatus of claim 10 wherein each expander means is tubular in form and has external recesses shaped and adapted tO receive respective ones of said head portions, each recess being defined in part by said companion outer surface; each expander means having circumferentially projecting dog portions located to either side of said recess and being defined in part by said companion inner surfaces.

Claim 15

The apparatus of claim 11 wherein said inner surfaces are inclined at an angle of about 20* and said outer surfaces are inclined at an angle of about 60*.