Abstract: A sheet metal tray for retaining corrugated fin strips for heat exchangers has a plurality of upright partitions spaced laterally apart to accommodate the corrugated strips. The tray has an open end wherein the bottom wall of the tray projects beyond the adjacent ends of the partitions and is formed with a plurality of inwardly extending notches adapted to interengage with spaced heat exchanger coolant tubes supported on an assembly fixture.

Abstract: A fluid die spring comprises a cylinder connected at one end to a reservoir of gas at high pressure. A piston in the cylinder has a smaller diameter rod projecting out the other end of the cylinder for engagement with a movable die member. The rod end of the cylinder has a high pressure seal engaging the rod and arranged to prevent leakage of liquid die lubricant into the cylinder.

Abstract: A nitrogen die cylinder is disclosed having an upright post threaded at its lower end into the wall of a manifold containing nitrogen at high pressure. The post has a central vertical passageway extending therethrough and communicating with the manifold. A cylindrical sleeve having a top wall is telescoped over the post. A seal at the upper end of the post engages the bore of the sleeve to form a chamber between the seal and the top wall of the sleeve which, when pressurized, urges the sleeve upwardly on the post. The top wall of the post has a noncircular socket therein which is accessible through an opening in the top wall of the sleeve which is normally closed and sealed by means of a threaded plug.

Abstract: A machine on which metal ribbon stock is corrugated has a toothed feed roll which engages the corrugated strip between successive corrugations to advance the strip lengthwise. Downstream from the feed roll is arranged one or more rotary-driven, toothed, unpacking rolls that are rotatably adjustable relative to the feed roll to stretch the corrugated strip advanced by the feed roll a predetermined amount so that, when the strip is cut to length at a further downstream station, it will have the desired number of corrugations per unit length.

Abstract: A tube cut-off unit is arranged at the downstream end of a tube mill and is powered by a drive unit mechanically driven by the main shaft of the mill which drives the tube forming rolls. The drive unit mechanically rotates a crank which, through a link, reciprocates a slide along the path of travel of the tube. A tube cut-off blade on the slide is cam actuated to sever the tube. Means are provided to insure that the slide is moving at a constant speed and at the same speed as the tube when the tube is being severed.

Abstract: A punch and retainer assembly wherein the punch has a non-circular punching end and a flattened surface at the upper end of its side wall. The punch also has an axially extending, radially inwardly inclined flat surface below the flattened side wall portion. The punch retainer includes a vertically movable latch having cylindrical surfaces adapted to engage the flat inclined surface on the punch and a flat inclined surface on the retainer in wedging relation to retain the punch within the retainer. Means are provided for permitting the punch to be inserted into the retainer only when the flattened surface thereof is aligned parallel with the axis of the latch. A strong leaf spring biases the latch downwardly into engagement with the flat inclined surface on the punch so that the cylindrical surface of the latch engages the flat inclined surface on the punch with line contact that is perpendicular to the vertical axis of the punch.

Abstract: A hydraulic cylinder arrangement of the type wherein the opposite ends of a cylinder are connected selectively to either a pump or sump by a control valve. Each end of the cylinder is provided with a pair of oppositely acting, uni-directional check valves, each connected to a port on the control valve by an individual conduit. The four check valves are so arranged that all the fluid discharged from either end of the cylinder in response to the reciprocation of the piston therein is constrained to flow to sump before it is pressurized and returned to the cylinder.

Abstract: A gas-operated piston cylinder assembly arranged between upper and lower die members of a press. The lower end of the cylinder communicates with a source of high pressure gas and also communicates through a passageway with the upper rod end of the cylinder which is sealed from the surrounding atmosphere. The piston rod has a cross sectional area only slightly smaller than the piston. The passageway between the lower and the upper ends of the cylinder contains a lubricant impregnated member and a by-pass controlled by a check valve which allows gas flowing from the rod end of the cylinder to the lower end thereof to bypass the lubricant impregnated member.

Abstract: A punch and retainer assembly wherein the punch has a non-circular punching end, a flattened surface at the upper end of the side wall thereof and a radially inwardly extending recess directly below the flattened side wall portion. The punch retainer includes a vertically movable latch adapted to engage within the recess on the shank of the punch and retain the punch within the retainer. Means are provided for limiting vertical movement of the latch so that the punch can be inserted into the retainer only when the flattened surface thereof is aligned parallel with the pivot axis of the punch. Spring means are also provided for maintaining the non-circular punching end of the punch in a predetermined circumferential angular relationship relative to the latch.

Abstract: A vertically oriented cylinder has a punch retainer firmly secured to its lower end. The piston within the cylinder has several legs which extend downwardly through and below the retainer. A stripper plate secured to the lower ends of the legs of the piston is biased downwardly by the fluid pressure in the cylinder chamber above the piston which is connected to a fluid pressure source.

Abstract: A stock lifter for progressive dies in the form of a fixedly mounted fluid cylinder designed to be charged with gas at a desired pressure. A piston within the cylinder has a piston rod projecting upwardly from within the cylinder so that its upper end is adapted to lift the stock when the downward pressure on the stock is relieved so that the piston is at all times biased upwardly. The cross sectional area of the lower side of the piston is substantially greater than the upper side of the piston and the portions of the cylinder above and below the piston are in free communication.

Abstract: A punch retainer is formed with a bore in its upper portion for releasably securing a punch therein. The lower portion of the punch retainer is formed as a cylinder for a vertically movable stripper piston. The portion of the cylinder above the piston is connected to a source of gas under pressure so as to bias the piston downwardly. The punch extends downwardly in sealed relation through a central bore in the piston and terminates slightly above the lower end of the piston when the piston is in its lowermost position.

Abstract: A gear rack pivotally mounted on the ram of a metal working press extends downwardly at an angle to the vertical in driving relation with a laterally offset drive gear on a device for transferring workpieces to successive stations in the press.

Abstract: A unitary punch and die assembly wherein the stripper spring for the punch comprises a fluid cylinder which communicates with a gas reservoir formed integrally with the punch and die holder and which is adapted to be charged with gas to a predetermined pressure so as to obtain a desired stripping force on the punch. The hold down sleeve on the punch is preferably also actuated by a fluid spring to obtain a preselected clamping force on the stock being punched.

Abstract: A corrugated thin metal strip is advanced through a cut-off mechanism having a movable upper blade and a lower stationary blade. A curtain of air is directed downwardly against the tip of the corrugated strip to momentarily arrest its movement with a return bend between a pair of adjacent convolutions of the strip centered over the stationary blade. The upper blade descends and shears the strip transversely along a return bend.

Abstract: A punch and retainer assembly wherein the punch has a flattened surface at the upper end of the side wall thereof and a radially inwardly extending recess directly below the flattened side wall portion. The punch retainer includes a vertically movable latch adapted to engage within the recess on the shank of the punch and retain the punch within the retainer block. Means are provided for limiting vertical movement of the latch so that the punch can be inserted into the retainer only when the flattened surface thereof is aligned parallel with the pivot axis of the latch.

Abstract: A flexible boot surrounds a piston rod and is sealed at one end to the free end portion of the piston rod and at its other end to the rod end of the associated cylinder. The head end of the cylinder is connected to a source of gas under pressure and the interior of the boot communicates freely with the interior of the cylinder at the rod end thereof. A check valve is provided for relieving the pressure in the boot when it reaches a predetermined value.

Abstract: A stamping press having a workpiece transfer mechanism connected thereto. The transfer mechanism includes a reciprocating carriage having a rigid cross arm thereon extending transverse to the path of travel of the carriage. A pair of laterally spaced, parallel finger bars extend lengthwise of the path of travel of the carriage and have one end thereof fixedly mounted on and supported on the opposite ends of the cross arm such as to reciprocate with the carriage. The other ends of the finger bars are slideably supported adjacent the die in the press. The finger bars have fingers thereon which are movable preferably in a vertical plane between work-engaging and work-releasing positions. In one embodiment the fingers are fixedly mounted on the finger bars and the finger bars are rotated to actuate the fingers in a vertical plane between work-engaging and work-releasing position. In another embodiment the fingers are raised and lowered in a vertical plane parallel to the axis of each finger bar.

Abstract: A chain drive for a workpiece transfer mechanism wherein a pair of coaxial rollers mounted on a chain extending around a pair of spaced sprockets engage the slotted legs of a yoke depending from a carriage. The carriage is reciprocated as the rollers travel around the endless path of the chain. At each sprocket guide tracks are provided which are engaged by the rollers on the chain to guide the rollers in an arcuate path around the sprockets.

Abstract: In a gas-operated cylinder, the surfaces of the cylinder and piston that are in sliding contact are lubricated by an oil-impregnated wick disposed in an annular chamber at the rod end of the cylinder. The wick extends through radially inwardly extending openings in the chamber to contact the piston rod and also through axial openings in the chamber to contact the back side of the piston when the latter moves to the rod end of the cylinder.