Abstract: In a fluid spring arrangement for a metal forming die assembly of the gas-operated, piston-cylinder type, the surfaces of the piston and cylinder which are in sliding contact are lubricated by lubricant entrained in the pressurized gas directed into the working chamber of the cylinder. The lubricant is contained in an apertured cartridge within the cylinder through which the gas is constrained to flow. A valve plate cooperates with an apertured wall of the cartridge to entrain lubricant in the gas when the flow of gas is into the cylinder and prevent the entrainment of lubricant when the flow of gas is out of the working chamber of the cylinder.

Abstract: A workpiece transfer mechanism for indexing workpieces through successive stations of a die in a stamping press wherein workpiece gripping finger bars are actuated by a cam mounted on the press ram to reciprocate therewith.

Abstract: Lubricating means for a piston-cylinder unit operated by non-lubricated gas under pressure comprising a passageway in the piston-cylinder unit extending from the surrounding atmosphere to the cylinder chamber on the side of the piston opposite that to which the pressurized gas is directed. A lubricant-impregnated material is located in the passageway so that, as air flows into said chamber in response to movement of the piston in the cylinder, the lubricant is entrained in the air and is carried into the cylinder to lubricate the contacting surfaces of the piston and cylinder. In addition, a lubricant-impregnated wick is arranged within the piston rod and contacts the conventionally used lubricant-impregnated felt ring on the piston to prolong the supply of lubricant to the ring.

Abstract: A method and apparatus for rolling metal ribbon stock into convoluted fin strip for use in heat exchangers is disclosed. The passageways defined by adjacent convolutions may be of zig-zag shape in a direction transversely of the strip by reason of the fact that the form rolls are designed such that the return bent portions connecting successive convolutions are initially formed as two symmetrical half sections separated by a sharp bend line extending transversely along the centerline thereof. After the strip emerges from between the form rolls it is gathered or compressed lengthwise in a conventional manner so that further bending of the convolutions is localized along said sharp straight bend lines.

Abstract: A die arrangement wherein selected dies are attached to their respective supports by fluid springs in the form of piston-cylinder assemblies which are in turn resiliently mounted on the die supports for pivotal movement as a unit.