Abstract: An intramedullary nail for the fixation of bone fractures is formed of two slidably engaging elongate members. One of the members includes an articulated channel which serves to bend the other member to form an expanding end region within the bone cavity to achieve fixation therein.

Abstract: A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator.

Abstract: An extractor for pulling individual tubes from a tube sheet in a heat exchanger. The extractor includes a pair of serrated, drive wheels or drivers mounted in a housing on parallel rotating shafts. The tube drivers have inclined teeth which project into opposite sides of a passageway along which a tube is drawn. The spacing between the drivers is adjustable to accommodate different sized tubes, and the drivers are spring biased towards each other, to provide a constant gripping force on a tube within the passageway. The drivers are respectively rotated by two hydraulic motors, with the hydraulic power supply connected in series, thereby providing substantially synchronous rotation of the drivers.

Abstract: A tillage implement comprising a plurality of coulters or discs is provided with disc cleaning means to prevent the accumulation of dirt and debris between adjacent coulters or discs. The disc cleaning means can comprise a rotatable belt mounted between adjacent coulters or discs and drive means operable to cause rotation of the belt. The drive means may comprise a drive gear secured to a power source. As the belt rotates, it removes soil from between adjacent coulters or discs.

Abstract: A check valve particularly useful for water well applications. The valve components are positioned at the low pressure, downstream side of a flexible poppet. A flexible guide, shaped generally as an inverted top hat, snaps into place in an annular groove and responds to longitudinally directed forces from the water flow and a biasing spring to forcibly retain the guide in the groove. A stem affixed to the poppet slides within an aperture of the guide and restricts the poppet to generally longitudinal motion.

Abstract: The present invention relates to a lever assembly which is coupled by a cable to operate a remote mechanism, such as a vehicle parking brake. The lever assembly comprises a lever pivotally mounted to a support member. A locking pawl pivotally mounted to the lever is adapted to engage one of a plurality of ratchet teeth on the support member for maintaining the lever in a selected pivoted position relative to the support member. The one end of the cable is coupled to the handle such that pivoting of the lever results in movement of the cable and operation of the remote mechanism. In accordance with the present invention, an adjusting device is provided for maintaining the cable within a predetermined tension range when the lever is in the non-operating position.

Abstract: A plastic pulsation bag for automobile gasoline filters and a method of making the same is disclosed. The bag comprises two opposing flexible membranes peripherally sealed together along their opposing sides. At least one of the opposing sides is recessed so that a pocket is formed by the sealed membranes for enclosing a gas which is preferably heavier than air. In a preferred method, a first step in forming the bag is to slopingly insert the membranes into an open-top chamber containing a body of gas, such that the recessed opposing sides pass obliquely through the upper surface of the gas and face away from the chamber. The membranes are then agitated within the chamber to release trapped air adjacent thereto, oriented in an opposing relationship, mounted upon opposing sealing dies, and then sealed together about their peripheries. Pulsation bags made in accordance with this invention are useful in preventing "water hammer" in certain large vehicle fuel systems.

Abstract: A diffusion pump capable of separating impurities from its pump fluid during operation is disclosed. Skimming drains are provided in the pump's boiler for periodically skimming the evaporative surface of the working fluid. This eliminates nearly all contaminants of higher molecular weight than the pump fluid. In the foreline of the pump, a series of peripheral gutters are provided for trapping, separating and draining off condensates. The gutters facilitate the removal of impurities of lower molecular weight than that of the pump fluid. Means are also provided for further removing trace quantities of residual volatile impurities which tend to backstream up the diffusion pump barrel. The highly purified pump fluid allows for a more vigorously working evaporative surface, thereby increasing the throughput of the diffusion pump. Together with the elimination of volatile impurities from the pump barrel, this facilitates the attainment of significantly higher ultimate chamber vacuum.

Abstract: A high pressure multi-purpose seal for use with pressure vessels and other equipment requiring demountable access fittings withstands pressures thousands of times above atmospheric pressure at both cryogenic and elevated temperatures. The cryogenic high pressure seal comprises a stack of indium, brass and fluorocarbon plastic sealing rings disposed about an access opening in the pressure vessel. A gland nut type closure is tightened against the seal stack which compresses it and causes the indium rings to extrude and seal against the closure and pressure vessel walls. The seal exhibits negligible leakage and provides exceptional pressurization and depressurization cycle life at both high pressures and cryogenic temperatures. The instant invention also comprehends a high pressure seal suitable for use at elevated temperatures (370.degree. to 400.degree. Celsius or 700.degree. to 750.degree. Farenheit).

Abstract: A diffusion pump capable of separating impurities from its pump fluid during operation is disclosed. Skimming drains are provided in the pump's boiler for periodically skimming the evaporative surface of the working fluid. This eliminates nearly all contaminants of higher molecular weight than the pump fluid. In the foreline of the pump, a series of peripheral gutters are provided for trapping, separating and draining off condensates. The gutters facilitate the removal of impurities of lower molecular weight than that of the pump fluid. Means are also provided for further removing trace quantities of residual volatile impurities which tend to backstream up the diffusion pump barrel. The highly purified pump fluid allows for a more vigorously working evaporative surface, thereby increasing the throughput of the diffusion pump. Together with the elimination of volatile impurities from the pump barrel, this facilitates the attainment of significantly higher ultimate chamber vacuum.

Abstract: A magnetic clutch or drag brake for a rotary shaft which is particularly adapted for use as a web or sheet tensioning control is disclosed. The device includes a first clutch element providing a selectively variable torque which is independent of shaft rotation or slip speed and a second clutch having an independently selectively variable torque which is dependent upon slip speed. The two clutch elements are associated in one housing between input and output shafts such that their clutching or braking action is cumulatively applied to the output shaft to provide an infinitely variable output from zero to maximum shaft speeds. The first clutch element utilizes the principal or magnetic hysteresis of a driven disc of high hysteresis-loss material while the second clutch element utilizes the principle of magnetic eddy current variations caused by an adjustable flux gate which varies the magnetic coupling between a driven and fixed member.

Abstract: Apparatus for furnishing weld material to a surface for welding thereto along a predetermined welding path, comprising an elongate guide (such as a tube) having a contacting surface (typically internal) substantially uniform in cross section and defining a longitudinal guide path (as by a slot opening) corresponding to the welding path, means for maintaining the guide in a position with the guide path adjacent to the surface to be welded and in registry with the welding path, weld material supply means in controlled contact with the guide (as inside the tube) and comprising an elongate flexible member having a contacting surface with its cross section (typically external) shaped to fit slidably in a predetermined position alongside the contacting surface of the guide (as inside the tube), a longitudinal opening through the elongate flexible member, and an elongate piece of flexible weld material (such as a wire) slidably positioned in and protruding from the opening, means for moving the weld material supplyi