Gripper assembly for downhole tools

A gripper assembly for use with a tool within a passage, said gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of said passage, and a retracted position in which said gripper assembly permits substantially free relative movement between said gripper assembly and said inner surface of said passage, said gripper assembly comprising:

• an elongated mandrel configured to be engaged with respect to said tool;
• a first toe support longitudinally fixed with respect to said mandrel;
• a second toe support longitudinally slidable with respect to said mandrel;
• a flexible elongated toe having a first end pivotally secured with respect to said first toe support and a second end pivotally secured with respect to said second toe support;
• a ramp having an inclined surface extending between an inner radial level and an outer radial level, said inner radial level being radially closer to the surface of said mandrel than said outer radial level, said ramp longitudinally slidingly engaged with said mandrel;
• and
• a roller rotatably secured to a central region of said toe, said roller configured to roll against said ramp;
• wherein longitudinal movement of said ramp causes said roller to roll against said ramp between said inner and outer levels to vary the radial position of said central region of said toe between a radially inner position corresponding to said retracted position of said gripper assembly and a radially outer position corresponding to said actuated position of said gripper assembly.

A gripper assembly for use with a tool within a passage, said gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of said passage, and a retracted position in which said gripper assembly permits substantially free relative movement between said gripper assembly and said inner surface of said passage, said gripper assembly comprising:

• an elongated mandrel configured to be engaged with respect to said tool;
• a first toe support longitudinally fixed with respect to said mandrel;
• a second toe support longitudinally slidable with respect to said mandrel;
• a flexible toe having a first end pivotally secured with respect to said first toe support and a second end pivotally secured with respect to said second toe support;
• a piston longitudinally slidable with respect to said mandrel;
• a ramp on an inner surface of said toe, said ramp sloping from a first end to a second end, said second end being radially closer to the surface of said mandrel than said first end;
• a slider element longitudinally slidable with respect to said mandrel and longitudinally fixed with respect to said piston;
• and
• a roller rotatably fixed with respect to said slider element, said roller configured to roll against said ramp;
• wherein said ramp is oriented such that longitudinal movement of said slider element causes said roller to roll against said ramp to vary the radial position of a central region of said toe between a radially inner position corresponding to said retracted position of said gripper assembly and a radially outer position corresponding to said actuated position of said gripper assembly, said piston and said slider element being movable between first and second longitudinal positions relative to said mandrel, such that when said piston and said slider-element are in said first position said first end of said ramp bears against said roller and said gripper assembly is in said retracted position, and such that when said piston and said slider element are in said second position said second end of said ramp bears against said roller and said gripper assembly is in said actuated position.

A gripper assembly for use with a tool that is configured to be within a passage, said gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of said passage, and a retracted position in which said gripper assembly permits substantially free relative movement between said gripper assembly and said inner surface of said passage, said gripper assembly comprising:

• an elongated mandrel configured to be engaged with respect to said tool;
• a first toe support longitudinally fixed with respect to said mandrel;
• a second toe support longitudinally slidable with respect to said mandrel;
• a flexible elongated toe having a first end pivotally secured with respect to said first toe support and a second end pivotally secured with respect to said second toe support;
• a slider element longitudinally slidable with respect to said mandrel, said slider element being longitudinally slidable between first and second positions;
• and
• one or more elongated toggles having first ends rotatably maintained on said slider element and second ends rotatably maintained on a central region of said toe, said one or more toggles adapted to rotate between a retracted position in which said second ends of said one or more toggles and said central region of said toe are at a radially inner level that defines said retracted position of said gripper assembly, and an actuated position in which said second ends of said one or more toggles and said central region of said toe are at a radially outer level that defines said actuated position of said gripper assembly;
• wherein longitudinal movement of said slider element causes longitudinal movement of said first ends of said one or more toggles and thereby rotates said one or more toggles, wherein when said slider element is in said first position said one or more toggles are in said retracted position, and when said slider element is in said second position said one or more toggles are in said actuated position.

A gripper assembly for anchoring a tool within a passage, said gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of said passage, and a retracted position in which said gripper assembly permits substantially free relative movement between said gripper assembly and said inner surface of said passage, said gripper assembly comprising:

• an elongated mandrel configured to be engaged with respect to said tool;
• a first toe support longitudinally fixed with respect to said mandrel;
• a second toe support longitudinally slidable with respect to said mandrel;
• a flexible elongated toe having a first end pivotally secured with respect to said first toe support and a second end pivotally secured with respect to said second toe support so that said first and second ends of said toe have an at least substantially constant radial position with respect to a longitudinal axis of said mandrel;
• a first interaction surface longitudinally slidable with respect to said mandrel, said first interaction surface being longitudinally slidable between a retraction position and an actuation position;
• and
• a second interaction surface on a central region of said toe, configured to interact with said driver;
• wherein longitudinal movement of said first interaction surface causes interaction between said first and second interaction surfaces substantially without sliding friction therebetween, said interaction varying the radial position of said central region of said toe, wherein when said first interaction surface is in said retraction position said central region of said toe is at a first radial distance from said longitudinal axis of said mandrel and said gripper assembly is in said retracted position, and when said first interaction surface is in said actuation position said central region of said toe is at a second radial distance from said longitudinal axis and said gripper assembly is in said actuated position.

A gripper assembly for use with a tool within a passage, said gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of said passage, and a retracted position in which said gripper assembly permits substantially free relative movement between said gripper assembly and said inner surface of said passage, said gripper assembly comprising:

• an elongated mandrel configured to be engaged with respect to said tool;
• a first toe support longitudinally fixed with respect to said mandrel;
• a second toe support longitudinally slidable with respect to said mandrel;
• a flexible elongated toe having a first end pivotally secured with respect to said first toe support and a second end pivotally secured with respect to said second toe support, said toe having a recess in a radial inner surface of a central region of said toe, said recess being partially defined by first and second sidewalls of said toe, said first sidewall having a first hole configured to receive an end of an axle, said second sidewall having a second hole configured to receive an end of an axle, said first sidewall including a first hollow inner region having a first portion configured to at least partially surround an end of an axle received within said first hole, said first hollow region having a first opening to the exterior of said toe, said first opening configured to be in fluid communication with the exterior of said tool when said gripper assembly is engaged with said tool;
• a ramp having an inclined surface extending between-an inner radial level and an outer radial level, said inner radial level being radially closer to the surface of said mandrel than said outer radial level, said ramp longitudinally slidingly engaged with said mandrel;
• an axle extending across said recess and having first and second ends positioned within said first and second holes, respectively, said axle being rotatable;
• a roller having a center hole through which said axle extends, said axle and said roller configured to rotate together, said roller positioned at least partially within said recess and configured to roll against said ramp;
• and
• a first pressure compensation piston within said first hollow region of said first sidewall, said first piston fluidly separating said first portion of said first hollow region from said first opening, said first piston configured to move within said first hollow region so that the pressure within said first portion is equalized with the pressure on the exterior of said tool when said gripper assembly is engaged with said tool;
• wherein longitudinal movement of said ramp causes said roller to roll against said ramp between said inner and outer levels to vary the radial position of said central region of said toe between a radially inner position corresponding to said retracted position of said gripper assembly and a radially outer position corresponding to said actuated position of said gripper assembly.

A gripper assembly for use with a tool within a passage, said gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of said passage, and a retracted position in which said gripper assembly permits substantially free relative movement between said gripper assembly and said inner surface of said passage, said gripper assembly comprising:

• an elongated mandrel configured to be engaged with respect to said tool;
• a first toe support longitudinally fixed with respect to said mandrel;
• a second toe support longitudinally slidable with respect to said mandrel;
• a flexible elongated toe having a first end pivotally secured with respect to said first toe support and a second end pivotally secured with respect to said second toe support;
• a ramp having an inclined surface extending between an inner radial level and an outer radial level, said inner radial level being radially closer to the surface of said mandrel than said outer radial level, said ramp longitudinally slidingly engaged with said mandrel;
• an axle having ends received within portions of said toe, said ends of said axle being at least partially surrounded by fluid regions;
• one or more pressure compensation pistons in said toe configured to move to equalize pressure in said fluid regions with the pressure on the exterior of said tool when said gripper assembly is engaged with said tool;
• and
• a roller secured on said axle so that said axle and said roller rotate together about an axis passing generally through a central region of said toe, said roller configured to roll against said ramp;
• wherein longitudinal movement of said ramp causes said roller to roll against said ramp between said inner and outer levels to vary the radial position of said central region of said toe between a radially inner position corresponding to said retracted position of said gripper assembly and a radially outer position corresponding to said actuated position of said gripper assembly.

A gripper assembly for anchoring a tool within a passage, said gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of said passage, and a retracted position in which said gripper assembly permits substantially free relative movement between said gripper assembly and said inner surface of said passage, said gripper assembly comprising:

• an elongated mandrel configured to be engaged with respect to said tool;
• an elongated toe having ends pivotably secured to elements of said gripper assembly;
• a driver longitudinally slidable with respect to said mandrel, said driver being longitudinally slidable between a retraction position and an actuation position;
• and
• a driver interaction element on a central region of said toe, configured to interact with said driver;
• wherein longitudinal movement of said driver causes interaction between said driver and said driver interaction element substantially without sliding friction therebetween, said interaction varying the radial position of said central region of said toe, wherein when said driver is in said retraction position said central region of said toe is at a first radial distance from said longitudinal axis of said mandrel and said gripper assembly is in said retracted position, and when said driver is in said actuation position said central region of said toe is at a second radial distance from said longitudinal axis and said gripper assembly is in said actuated position, said second radial distance being greater than said first radial distance.