The valve has a cylindrical, cartridge-like housing in which a piston is slidably disposed. The piston subdivides the housing into an outer chamber, at one housing end, into which oil under pressure is admitted, and an inner chamber from which oil is discharged. Ports formed in the housing open onto the inner chamber and allow the oil to pass therethrough and on into an associated air compressor. The other end of the valve housing defines a control chamber. The piston has a depending, cylindrica...

A tray forming machine comprising an infeed station for accepting a blank of corrugated plastic, and a transfer mechanism which automatically conveys the blank along a plane into a blank receiving station between a tray forming ram and a forming tool frame. The tray forming ram moves downward along a vertical path carrying the blank through the forming tool frame, during which the blank is folded into a generally upright tray configuration by a series of vertically displaced side and end forming...