Abstract: What is disclosed is an improvement in a system for producing a vacuum in which both liquid and gas streams are involved. Specifically, in one aspect the improvement is in a vacuum system for extruding plastic pipe having conventional extrusion apparatus, vacuum tank, mold and vacuum and liquid pumps with a chilled water flow system, the improvement being characterized by an outer housing connected intermediate the effluent water conduit and the liquid pump with a vacuum port connected with a vacuum pump; and an internal sleeve interiorly of the outer housing defining an annular space about the sleeve and directing the combined stream directly into the entrance to the liquid pump so that by inertia the liquid is sucked into the liquid pump whereas the gas is diverted by the vacuum pump to maintain the pressure without flooding the vacuum pump.

Abstract: A method and apparatus for belling a plastic pipe wherein the pipe is heated until a predetermined force can move the pipe onto a mandrel; the magnitude of the force being such that the pipe is heated to a temperature between its memory temperature and its breakdown temperature.

Abstract: A machine, and method, for tumbling objects or parts, generally of plastic material, to remove thin flange-like projections left along mold mating lines and frequently referred to as "flash". An advancing belt-like conveyor has a portion disposed to define an object-supporting surface so upwardly sloped in the direction of conveyor advance, as to cause tumbling and consequent deflashing of a mass of objects supported on said surface. The conveyor is also movable between two positions in which the objects are, respectively, loaded upon and automatically discharged from the conveyor. In the illustrated apparatus these are upper and lower positions. Tumbling occurs in the upper position, and discharge takes place in the lower position, under the influence of the advancing movement of the conveyor. The system includes mechanism for effecting additional cleaning of the objects, while tumbling on the conveyor, by subjecting them to a blast of impact cleaning media.