Abstract: An oilless reciprocating compressor for use in a refrigerated controlled atmosphere has an uncooled, fully sealed crankcase. A bypass tubing connects the interior of the crankcase with the inlet of the cylinders, so that blow-by is returned from the crankcase to the inlet of the cylinder for recirculation. In consequence no blow-by gas escapes into the controlled atmosphere. The device includes standard pistons, and has an improved cylinder head seal utilizing o-rings.

Abstract: A cylinder and piston construction for a compressor or vacuum pump has a cylinder defined by co-axial cylinder and guideway sleeves. The guideway sleeve is larger in diameter than the cylinder sleeve and the cylinder sleeve extends axially into the guideway sleeve. A piston has a cylindrical base which is guided via skirt bearings in the guideway and a head which extends from the base into the compression chamber defined by the cylinder sleeve and has a piston ring which forms a sliding seal with the cylinder sleeve. An annular cavity is defined between the piston head and the piston base into which the cylinder sleeve extends so that the top skirt bearing is positioned closer to the top of the piston head and further away from the bottom skirt bearing so as to steadily guide the piston head in the cylinder sleeve, thereby reducing wear and increasing the life of the pump.

Abstract: An oilless reciprocating air compressor that is mountable on the inside wall of a cargo container. The compressor has a high strength cast metal crank case and a lighter motor housing attached thereto. A special bracket is provided that attaches to both the crank case and the motor housing to support the motor shaft in a horizontal plane and the opposed cylinders of the compressor in a vertical plane adjacent to the wall. Because this compressor mounted inside the container cooling fans and the like are not required, thus lightening the compressor and allowing for a compact unit that can be safely secured to the cargo container wall.