Abstract: A method and apparatus for quenching a gas stream in the production of vinyl chloride monomer includes the use of a knock back condenser and a plurality of column fractional distillation trays disposed within the quench column, and a liquid stream of 1,2-dichloroethane, vinyl chloride, and hydrogen chloride may be removed from the bottom column fractional distillation tray.

Abstract: An investment casting process utilizes a temporary mold which is formed by pouring a liquid over a positive pattern, and cooling the liquid until it solidifies. The positive pattern is removed, and a temporary pattern is formed by pouring another liquid into the cavity of the temporary mold, and cooling the second liquid until it solidifies. The temporary mold may then be melted or dissolved to leave a temporary pattern, which may be coated with a ceramic slurry to form a ceramic shell. The temporary pattern may then be melted or dissolved in order to remove the temporary pattern from the ceramic shell. The ceramic shell may be filled with molten metal which is allowed to solidify to form the final cast piece.

Abstract: An air filtering apparatus and filter mounting device for sealing a filter within an air filtering apparatus, utilizes at least one cam surface to force a filter to compress a gasket to provide an effective seal between the air filter and its associated air outlet.

Abstract: A nailing system, condylar anchor, and method for treating fractures of a bone include an intramedullary nail, whose lower end passes through a condylar anchor in a sliding and mating relationship, whereby the patient may exert weight upon the bone and relative movement between the intramedullary nail and condylar anchor is permitted.

Abstract: An upflow/downflow high efficiency furnace includes a means for mounting a secondary heat exchanger by use of a hinge member, which permits the furnace to be installed in either an upflow or downflow mode of operation, without any modification to the furnace as manufactured.

Abstract: A method and apparatus for verifying the position of a lesion in a patient's body compares the location of the lesion in CT slices with the position of the lesion in ultrasound images taken while the patient lays on the treatment table of a linear accelerator.

Abstract: A method and apparatus for cementing a casing string utilizes a port collar which may be hydraulically opened and mechanically closed, and permits the passage of downhole tools through the port collar, without opening the port collar.

Abstract: A football helmet motion restrictor is provided which can be adjusted to vary its size, and does not reduce the size of the neck opening of the shoulder pads to which the motion restrictor is mounted.

Abstract: A vessel occluder for providing permanent occlusion of a vessel in a person utilizes a flexible closure member attached to at least one metallic radially expandable, generally tubular shaped stent, the flexible closure member having a generally tubular shaped cross-sectional configuration.

Abstract: A backwash valve for use in a sucker-rod actuated fluid pump, may be selectively actuated to permit both the standing and traveling ball valves to be unseated at the same time permit the pump to be backwashed and/or the production tubing string drained.

Abstract: A tissue compensation system and method for making a tissue compensator utilizes a plurality of elongate rods, one end of which contact the treatment surface on the patient, and the other end of which contact and deform a flexible membrane containing a quantity of a material substantially equivalent to tissue of the patient.

Abstract: An aortic graft, and method and apparatus for repairing an abdominal aortic aneurysm includes a tubular graft which is intraluminally delivered through the aorta and secured to the aorta by the expansion and deformation of a thin-walled tubular member.

Abstract: A pilot pressure switch for a furnace detects the fluid pressure within the pilot line for a pilot flame, and upon the fluid pressure in the pilot line exceeding a predetermined value, an electrical signal from a thermostat may be passed to a furnace blower control to operate the furnace main blower and furnace vent blower.

Abstract: An offshore support structure utilizes a central support structure having four substantially parallel tubular legs, and three outrigger support structures associated with the base of the central support structure.

Abstract: A metal-to-metal sealing method and apparatus for use on oil and/or gas wells, utilizes an upper seal member and a lower seal member, wherein the energizing of the seal members is staged to cause the lower seal member to become sealingly engaged. before the upper seal member becomes sealingly engaged. The seal members may have two seals of different construction; one seal is an interference type seal, and the other seal is a wedge type seal.

Abstract: A bilateral intra-aortic bypass graft and method and apparatus for repairing an abdominal aortic aneurysm includes two tubular grafts which are intraluminally delivered to the aorta and secured to the aorta by the expansion and deformation of two expandable and deformable tubular members.

Abstract: Apparatus for supporting a vertical member in an offshore environment, utilize support members which are secured to the vertical member by a doubler plate which is guided into an abutting relationship with the vertical member.

Abstract: A non-contact method and apparatus for measuring dimensional variables of a threaded exterior surface of a length of pipe utilizes at least one laser generated parallel scanning light beam transmitter and at least one receiver which is disposed on a frame which moves with respect to the longitudinal axis of the pipe, to measure the amount of the scanning beam width which is blocked by the threaded exterior surface at a plurality of sequential locations along the longitudinal axis of the pipe, and the measured amounts are stored as a function of the sequential locations to produce a profile of the threaded exterior surface and to determine from the profile a desired dimensional variable of the threaded exterior surface.

Abstract: A method and apparatus for performing stereotactic surgery upon a target within a skull establishes a first, predetermined geometric relationship between a skull mount fixture mounted on the skull and a scanning table surface upon which the skull is supported; and that geometric relationship is duplicated by a displacement bar mounted upon the skull mount fixture.