Abstract: An actuator and control algorithm which provide an operator with the ability to intuitively and responsively maneuver heavy work-pieces with ease and precision. The structure of the apparatus may provide a hoist with a compliant sensing system to measure the weight of the payload. The compliant sensing system may result in smaller dead-bands than are realizable with traditional force sensing methods. At the command of the user, the control algorithm may switch between two distinct operational modes: float mode and manual mode. In float mode, the hoist actively counterbalances the weight of the load, allowing it to feel substantially weightless in the operator's hands. The operator can apply forces directly to the payload to accelerate it in the desired vertical direction. Because of the small dead-band realized with compliant sensing, the payload may be highly responsive to the operators force inputs. As a result, the payload may be intuitively maneuvered at very high speeds, as well as very low speeds.

Abstract: An actuator and control algorithm which provide an operator with the ability to intuitively and responsively maneuver heavy work-pieces with ease and precision. The structure of the apparatus may provide a hoist with a compliant sensing system to measure the weight of the payload. The compliant sensing system may result in smaller dead-bands than are realizable with traditional force sensing methods. At the command of the user, the control algorithm may switch between two distinct operational modes: float mode and manual mode. In float mode, the hoist actively counterbalances the weight of the load, allowing it to feel substantially weightless in the operator's hands. The operator can apply forces directly to the payload to accelerate it in the desired vertical direction. Because of the small dead-band realized with compliant sensing, the payload may be highly responsive to the operators force inputs. As a result, the payload may be intuitively maneuvered at very high speeds, as well as very low speeds.

Abstract: A method and apparatus for anchoring a tool within a cased borehole wherein at least one piston connected with respect to the tool includes an associated anchor shoe. The anchor shoe has a penetration means, such as a plurality of wheels having a sharp outer periphery, for engagement with the cased borehole. A packer having a rigid component, such as a plurality of concentric rings, is connected with respect to the tool, opposite the piston. The packer may also have a sealing member for creating a sealed engagement between the tool and the cased borehole. When the piston is extended, the anchor shoe contacts the cased borehole and centers the tool with respect to the cased borehole. When the piston is extended, the packer also engages the cased borehole and maintains the position of the tool as well as creating a sealed connection between the tool and the cased borehole.

Abstract: An apparatus and method are disclosed for actively cooling instrumentation, in particular electronic circuits, in especially, high temperature environment. This apparatus has a tank containing a cooling agent, a heat exchanger to transfer heat from the instrumentation to the cooling agent, a compressor and a tank to hold cooling agent removed from the first tank. In this operation, the cooling agent tank is located in close proximity to the instrumentation. As the instruments generate heat, the heat is transferred through the heat exchanger to the cooling agent. The cooling agent boils and vaporizes from the heat and is pumped out of the tank by a compressor. As the cooling agent vaporizes and is pumped out of the tank, heat contained in the cooling agent is transferred out of the tank as well. The rate at which the vapor is pumped out of the tank controls the temperature of the cooling agent in the tank.

Abstract: An apparatus is disclosed for perforating, testing and resealing casing in an earth formation borehole. The apparatus is moveable through the casing. The apparatus can also be mounted on a wireline, on tubing or on both. A perforating device is mounted in the apparatus for producing a perforation in the casing. The perforating device contains a flexible drilling shaft that enables the drilling of perforations in the casing of lengths greater than the diameter of the borehole. The apparatus will usually contain components for hydraulic testing and sampling from the formation behind the casing. Also mounted in the apparatus is a device for plugging and resealing the perforation with a solid plug.