Abstract: An improved molded plastic elbow and a related mold assembly and manufacturing method are provided, wherein the elbow defines an internal flow path having a smoothly radiused inside turn. The elbow is formed by injecting plastic material into a tubular mold cavity formed by closed mold members in cooperation with a pair of slidably retractable core units of circular cross section and having distal ends in mating, angularly set end-to-end contact to form the internal flow path having a turn formed along the length thereof. Each core unit comprises an outer core pin to form an outer portion of the flow path and including a ramped track for slide-fit mounting of an inner slide segment which forms an inner portion of the flow path and further includes a curved inside edge to form a portion of the smoothly radiused inside turn.

Abstract: An improved molded plastic elbow and a related mold assembly and manufacturing method are provided, wherein the elbow defines an internal flow path having a smoothly radiused inside turn. The elbow is formed by injecting plastic material into a tubular mold cavity formed by closed mold members in cooperation with a pair of slidably retractable core units of circular cross section and having distal ends in mating, angularly set end-to-end contact to form the internal flow path having a turn formed along the length thereof. Each core unit comprises an outer core pin to form an outer portion of the flow path and including a ramped track for slide-fit mounting of an inner slide segment which forms an inner portion of the flow path and further includes a curved inside edge to form a portion of the smoothly radiused inside turn.

Abstract: An improved molded plastic elbow and a related mold assembly and manufacturing method are provided, wherein the elbow defines an internal flow path having a smoothly radiused inside turn. The elbow is formed by injecting plastic material into a tubular mold cavity formed by closed mold members in cooperation with a pair of slidably retractable core units of circular cross section and having distal ends in mating, angularly set end-to-end contact to form the internal flow path having a turn formed along the length thereof. Each core unit comprises an outer core pin to form an outer portion of the flow path and including a ramped track for slide-fit mounting of an inner slide segment which forms an inner portion of the flow path and further includes a curved inside edge to form a portion of the smoothly radiused inside turn.

Abstract: An improved molded plastic elbow and a related mold assembly and manufacturing method are provided, wherein the elbow defines an internal flow path having a smoothly radiused inside turn. The elbow is formed by injecting plastic material into a tubular mold cavity formed by closed mold members in cooperation with a pair of slidably retractable core units of circular cross section and having distal ends in mating, angularly set end-to-end contact to form the internal flow path having a turn formed along the length thereof. Each core unit comprises an outer core pin to form an outer portion of the flow path and including a ramped track for slide-fit mounting of an inner slide segment which forms an inner portion of the flow path and further includes a curved inside edge to form a portion of the smoothly radiused inside turn.

Abstract: An improved dual seal pipe coupling is provided of the type having matingly interfitting male and female pipe fittings formed on adjacent ends of a pair of conduit members, wherein at least one of a pair of seal rings is vented at low pressure to prevent pressure build-up and potential seal ring distortion or damage upon initial assembly of the pipe fittings. The seal rings are seated respectively within a pair of axially spaced-apart recessed grooves formed on one of the pipe fittings for slidably and sealingly engaging the other one of the pipe fittings upon assembly therewith. A bypass vent is formed in at least one of the seal ring grooves, to include a shallow recessed channel underlying the associated seal ring and leading axially to a smoothly curved and generally arch-shaped relief port formed in an outboard side wall of the seal ring groove.

Abstract: A device for extracting energy from sea waves by the motion of a submerged cylinder held normal to the direction of motion of the waves by tie members at each end of the cylinder. The tie members at their other respective ends are moored to the sea bed. Changes in the load on the tie members are arranged to turn in one direction a drum drivably connected to a vane pump. A spring, or a counterweight acting on a cam-shaped pulley, is arranged to apply a biasing load to the drum in the other direction so as to produce an oscillatory movement of the drum from changes in load on the tie members and drive the pump. A hydraulic motor connected to an electric generator is driven by the pump.The drum may be situated at the moorings on the sea bed, or at the cylinder.