Abstract: A substantially constant force actuator that is applicable to centralizers, anchors and tractors for use in wells and is applicable to lifting devices such as jacks and load supporting devices. One or more sets of linkage arms are angularly movable by the force of one or more force transmitting members from a minimum angle with the force transmitting members at maximum spacing to a maximum angle with the force transmitting members at minimum spacing to impart a substantially constant force to an object or surface, with the direction of the force being substantially perpendicular to the direction of relative linear movement of the force transmitting members. With the linkage arms at their minimum angles, movement control elements on at least one of the force transmitting members react with guide surfaces of the linkage arms to achieve angular linkage movement and to develop a substantially constant force during angular linkage movement.

Abstract: A linkage apparatus for selectively gripping and releasing the inside walls of a conduit, the apparatus comprising: a first arm; a bi-directional gripping cam rotatably attached to the arm; and an extension and locking device adapted to selectively radially extend the arm from a tool housing to an inside wall of a conduit and adapted to selectively lock the arm in an extended position.

Abstract: A substantially constant force actuator that is applicable to centralizers, anchors and tractors for use in wells and is applicable to lifting devices such as jacks and load supporting devices. One or more sets of linkage arms are angularly movable by the force of one or more force transmitting members from a minimum angle with the force transmitting members at maximum spacing to a maximum angle with the force transmitting members at minimum spacing to impart a substantially constant force to an object or surface, with the direction of the force being substantially perpendicular to the direction of relative linear movement of the force transmitting members. With the linkage arms at their minimum angles, movement control elements on at least one of the force transmitting members react with guide surfaces of the linkage arms to achieve angular linkage movement and to develop a substantially constant force during angular linkage movement.

Abstract: A linkage apparatus for selectively gripping and releasing the inside walls of a conduit, the apparatus comprising: a first arm; a bi-directional gripping cam rotatably attached to the arm; and an extension and locking device adapted to selectively radially extend the arm from a tool housing to an inside wall of a conduit and adapted to selectively lock the arm in an extended position.

Abstract: A connector latch includes a housing body having an internal cavity, a grippable member slidably coupled to the housing body, and a hydraulic mechanism on the housing body for delaying sliding of the housing body relative to the grippable member when an external force is applied to the housing body.

Abstract: A down-hole tool includes a first and second portion that are moveable relative to one another, but are electrically coupled together. A rigid tube formed into a helical coil extends between the first and second portions. The helical coil is expandable and compressible in response to movement between the first and second portions. A conductor is positioned within the helically wound tube and is adapted to pass electrical signals between the first and second portions.