Abstract: Bone cement is removed from a bone cavity, such as the intramedullary canal, during a prosthetic revision. The bond cement is pre-molded by a thermal chisel which includes a shaft for extending into the bone cavity, a plasticizer chisel on a working end of the shaft, and a heat element carried by the shaft for heating the chisel to a temperature within a range of temperatures sufficient to plasticize the bone cement. This deforms and weakens the bone cement upon direct non-impact type contact between the heated tip of the chisel and the cement. The cement is removed by pre-molding it with the heated working end of the thermal chisel, preferably by molding a distally located circumferential furrow in the bone cement and then molding circumferentially spaced apart longitudinal furrows from the circumferential groove to the proximal end of the bone cement.

Abstract: Disclosed is an endoprosthesis device and method of installing the same immovably in a medullary canal under a constant predetermined uniformly distributed pressure. The rigid prosthesis stem is typically embraced by an elastomeric element designed for continuous pressurization into compressed resilient anchorage with the medullary canal surface. The tubular elastomeric element can be pressurized in various ways such as by a captive gas, or by a fluent material until this material takes a set, or by a combination of pressurized gas and settable fluent material. When a captive pressurized gas is used, along or with a settable material, it provides a major portion of the elastic energy anchoring the prosthesis immovably in place; and when a settable pressurizing medium is used, the elastic energy is stored in the compressed thick elastomer. The constant elastic energy fosters bone growth to augment prosthesis anchorage.

Abstract: An endoprosthesis is immovably anchored in a medullary canal under a constant predetermined uniformly distributed pressure. The rigid prosthesis stem is typically embraced by an elastomeric element designed for continuous pressurization into compressed resilient anchorage with the medullary canal surface. The tubular elastomeric element can be pressurized in various ways such as by a captive gas, or by a fluent material until this material takes a set, or by a combination of pressurized gas and settable fluent material. When a captive pressurized gas is used, alone or with a settable fluent material, it provides a major portion of the elastic energy anchoring the prosthesis immovably in place; and when a settable pressurizing medium is used, the elastic energy is stored in the compressed thick elastomer. The constant elastic energy fosters bone growth to augment prosthesis anchorage. Permanent anchorage is achieved virtually instantly following alignment and pressurization of the prosthesis.

Abstract: Bone cement is removed from a bone cavity, such as the intramedullary canal, during a prosthetic revision. The bone cement is pre-molded by a thermal chisel which includes a shaft for extending into the bone cavity, a plasticizer chisel on a working end of the shaft, and a heat element carried by the shaft for heating the chisel to a temperature within a range of temperatures sufficient to plasticize the bone cement. This deforms and weakens the bone cement upon direct non-impact type contact between the heated tip of the chisel and the cement. The cement is removed by pre-molding it with the heated working end of the thermal chisel, preferably by molding a distally located circumferential furrow in the bone cement and then molding circumferentially spaced apart longitudinal furrows from the circumferential groove to the proximal end of the bone cement.

Abstract: A magnetically operated fail-safe cutoff valve of general application and particularly suitable for down hole fluid well applications is provided having a simple highly reliable valve for equalizing the pressure across the main cutoff valve while closed thereby permitting the same to be opened. All operating components can be either removably installed internally of a tubing string or as a portion of the string itself. In either case, typical wire line operations can be conducted through and past the lower end of the cutoff valve since the flow path of each of the illustrative embodiments provides an unobstructed linear flow path therethrough when the valve is open. The pressure equalizing valve includes multiple flow passages and is controlled by a shrouded annular armature operable independently of a tubular armature controlling the main cutoff valve. The two armatures may be located in either common or separate flux circuits.

Abstract: An armature position monitor for determining the position of an armature within a solenoid and any device controlled thereby. By way of example, the monitor is useful to indicate the position of a solenoid controlled valve such as a sub-surface safety cutoff valve by detecting and utilizing a signal generated in a solenoid actuator for the armature upon the movement thereof toward or away from its extended position to control the power supplied to the solenoid.

Abstract: Validator-controlled apparatus responsive to the inspection and validation of a plaque as genuine cooperating with a timer to control the power supply to and operation of a plurality of electrical components for one or consecutive predetermined periods. In an illustrative application of the apparatus, the validator inspects and authenticates a coded plaque of paper currency or a coded card as a prerequisite to the control and use of a room for a measured period of time equipped with one or more electrical components. One of the controlled components is a lock for the room door or barrier which re-locks after entrance of the patron or patrons and remains locked from its exterior but is manually releasable from the interior at any time. The apparatus includes provision for disabling the plaque validator and the door lock during the decrement of an existing predetermined time period.

Abstract: A tandem solenoid fail-safe sub-surface safety cut-off valve for fluid wells controllable from the surface and suitable for installation at substantially greater depths than prior constructions. The valve assembly may be installable and retrievable either via wire line or tubing techniques and utilizes tandem electromagnetic means to operate either a flapper or a ball cut-off valve. The solenoid coils embrace a landing nipple portion of the tubing string or the tubing string itself and hold either type of cut-off valve open against spring pressure only so long as the coils are energized thereby providing surface control of the safety cut-off valve normally and assurance of closing of this valve by energy stored in spring means in the event of power failure through accident or some catastrophe as well as automatic closure if flow velocity increases beyond a predetermined safe value.

Abstract: A fail-safe sub-surface safety cut-off valve for fluid wells controllable from the surface and suitable for installation at substantially greater depths than prior constructions. The valve assembly is installable and retrievable via wire line technique and utilizes an electromagnetic means to operate either a flapper or a ball cut-off valve. The operating solenoid coil embraces a landing nipple portion of the tubing string and is outside the production flow. This solenoid supplies the power to open either type of cut-off valve and holds the latter open only so long as the solenoid is energized thereby providing surface control of the safety cut-off valve normally and assurance of closing of this valve in the event of power failure through accident or some catastrophe as well as automatic closure if flow velocity increases beyond a predetermined safe value.

Abstract: A fail-safe sub-surface safety cut-off valve for fluid wells controllable from the surface and suitable for installation at substantially greater depths than prior constructions. The valve assembly is installable and retrievable via wire line technique and utilizes an electromagnetic means to operate either a flapper or a ball cut-off valve. The operating solenoid coil embraces a landing nipple portion of the tubing string and is outside the production flow. This solenoid supplies the power to open either type of cut-off valve and holds the latter open only so long as the solenoid is energized thereby providing surface control of the safety cut-off valve normally and assurance of closing of this valve in the event of power failure through accident or some catastrophe as well as automatic closure if flow velocity increases beyond a predetermined safe value.