Abstract: A self contained gas spring interchangeable with a coil spring comprising a cylindrical body having a constant diameter external cylindrical surface, the cylindrical body having open ends and a piston within said cylindrical body and having one end projecting through one of the openings of the cylindrical body. The piston and the cylindrical body have interengaging flanges that limit the outward movement of the piston relative to the cylindrical body. A plug is positioned in the other end of the cylindrical body to close the opening of the cylindrical body. A charging valve is positioned in the plug for charging the interior of the gas spring. The piston has a hollow inner end with an inner surface tapering outwardly and axially toward the plug. The plug has a generally complementary surface such that the piston can move downwardly about a portion of the plug thereby substantially reducing the height of the gas spring.

Abstract: The present invention relates to a pneumatic press counterbalance which holds selected parts of a press in the same relative engagement during the return stroke of a ram as during the power stroke of that ram. The counterbalance includes a base plate adapted for connection to a first part of a press. An elongated cylindrical base tube having an open end is mounted on the base plate and has a center axis substantially perpendicular to the base plate. A resilient unconfined tubular bellows for holding air has a pair of opposed ends. The bellows has an elongated tubular resilient sleeve connecting the open ends and formed integral therewith. One of the open ends of the bellows is sealingly connected to the base tube. A first portion of the tubular sleeve surrounds a portion of the base tube. A second portion of the tubular sleeve is connected to the first portion by a fold in the sleeve and has a part surrounding the first portion. A movable plate is connected to the other end of the bellows.

Abstract: A pneumatic die cushion for use in a power press is the subject matter of this invention. The die cushion includes a pair of spaced substantially parallel plates with resilient bellows for resiliently spacing apart the plates. A plurality of limiter pins are releasably secured to one of said spaced plates. Each of said limiter pins has an end threadedly mounted in one of said plates. Each of said limiter pins is movable relative to the other of said plates. A stop mechanism is mounted on the other end of each limiter pin for limiting movement of the first mentioned plate away from the other plate. A limit sleeve is mounted on each of the limiter pins to control the minimum spacing between the plates. A quick change adaptor plate is fixed to one end of the bellows. The quick change adaptor plate has a pair of opposed ears. A mechanism is provided to releasably secure the ears of the quick change adaptor plate to said one of said plates to secure said one end of the bellows to said one of said plates.

Abstract: A press cushion assembly includes a variable volume chamber which is expanded during operation of the press to an open condition and is contracted during operation of the press to a closed condition. During expansion of the variable volume chamber, a flow of lubricating liquid is conducted to the variable volume chamber from a reservoir. At the same time, a flow of gas is also conducted from the reservoir to the variable volume chamber. Upon closing of the press and contraction of the variable volume chamber, a flow of lubricating fluid and gas is conducted from the variable volume chamber back to the reservoir. The cushion assembly may include a manifold plate in which a plurality of piston and cylinder assemblies are mounted. A reservoir disposed in the manifold plate is connected in fluid communication with the piston and cylinder assemblies by a plurality of passages. Check valves may be provided in the passages so that the lubricating fluid can flow in only one direction.

Abstract: A mechanical, vibration-preventing means to be used on mechanical and hydraulic presses, bar cutters, shearing machines and the like preferably cyclicly working machine tools with a pulse-like pressing process is adapted to absorb the stroke at punching and cutting in plates, bars, and the like articles of metal, plastics or another material by the resilient energy deriving from the deflection of the machine frame instead of being converted into vibrations and noise immediately after break through of the material being converted directly into rotational energy in a flywheel through a roller screw connection. This roller screw connection transforms the translatory movement of the machine tools into rotation.

Abstract: A nitrogen die piston-cylinder unit has a central post threaded at one end into a nitrogen manifold. The piston has an axial bore therethrough. A sleeve closed at one end is telescoped over the free end of the post and is vertically slideable thereon. The upper end of the post has an annular seal thereon in sliding sealed engagement with the bore of the sleeve. A key and keyway formed on the inside of the sleeve and the outside of the post are arranged to interengage when the sleeve is fully telescoped over the post to prevent relative rotation therebetween. The exposed end face of the sleeve is formed with recesses adapted to be engaged by a spanner wrench to enable the unit to be removed from the threaded port of the manifold when the key is engaged with the keyway.

Abstract: There is disclosed a piston-cylinder assembly for use as a die spring wherein one end of the cylinder is connected to the source of nitrogen at high pressure to bias the piston outwardly through the opposite open end of the cylinder. The open end of the cylinder is provided with a high pressure seal and the opposite end of the piston is likewise provided with a high pressure seal. An annular chamber of relatively small cross sectional area is provided between the piston and the cylinder. A valve stem on the piston controls a passageway communicating with the annular chamber. Axial pressure is applied to the seal on the cylinder to produce firm sealing engagement with the piston by pressurizing the annular chamber or by arranging a compression spring between the seal and a shoulder on the cylinder.

Abstract: A piston-cylinder unit for use in a die is threaded into a port of a nitrogen manifold. The piston has a seal thereon slideably engaging the cylinder bore and has a rod projecting out one end of the cylinder, the rod being biased by the gas pressure at the threaded end of the cylinder into engagement with a die member reciprocated in response to reciprocation of the ram of the press in which the die is mounted. The portion of the cylinder threaded into the manifold has a bleed passageway therethrough which communicates with the interior of the cylinder below the seal on the rod when the press ram is at bottom dead center position and with the interior of the cylinder above the seal on the piston when the piston rod is fully retracted.

Abstract: A pneumatic spring for use in absorbing an external force by compressing gaseous fluid trapped therein. The pneumatic spring includes internal valves for recharging and for relieving excessive pressure. In one form, the pneumatic spring comprises an outer housing defining an open-ended outer cylinder and an inner cylinder slidingly and sealingly positioned in the outer cylinder. The inner cylinder has a cylindrical side wall and end walls and a rod extends from the inner end wall of the outer cylinder through the inner end wall of the inner cylinder. A piston is fixed on the rod within the inner cylinder, thereby defining a first chamber between the inner end of the outer cylinder and the inner end wall on the inner cylinder and a second chamber between the piston on the rod and the outer end wall of the inner cylinder. The chambers are isolated from one another.

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 new breed of die cylinders operating at 1000-5000 psig. working fluid pressures and adaptable for use individually or by manifolding with punch presses to cushion dies can be operated with maximum rated pressure force against a force which a ram develops in one direction and in the opposite direction with partial pressure force which the die cylinders exert when force balanced. The following is accomplished by loading a piston underside by the same working fluid pressure when the piston bottoms inside a cylinder housing at the end of the ram induced stroke enabling an instant high pressure surge of fluid, be it Nitrogen gas or other working fluid, to enter the piston underside provided with a piston rod and exert a resistance force proportional to the net free area exposed thereto thereby providing force balanced cylinder operation.

Abstract: A shock absorbing device in a press is formed by having a telescopically sliding member fastened to the punch plate of the press and a stopper member fastened to the die plate of the press and placing an oil of high viscosity between the post and the outer cylinder of the telescopically sliding member. This shock absorbing device damps the unloading impact produced when the punch of the press collides with a workpiece and fractures it and, thereby, abates the noise generated from the press, the tool and the workpiece.

Abstract: An impact damper for use, for example, between the stationary and reciprocating parts of a stamping machine to reduce the noise produced at the end of each stamping operation, consists of a two-stage telescopic gas pressure cylinder 10. A base 3 of the cylinder is fixed on the stationary part of the machine and the head 33 of an internal piston 14 is in permanent engagement with the reciprocating part 6. As the part 6 moves downwards, the piston 14 is retracted, but at first an external piston 13 remains stationary. There is therefore a small resistance to movement of the part 6. As the part 6 approaches the end of its downward movement at which noise is generated at the end of a stamping operation, the head 33 engages a ring 34 at the upper end of the external piston 3 so that the external piston also then starts to be retracted.

Abstract: A resilient stop block for gradually loading the ram of a press for scoring easy open can ends to assure an accurately controlled residual and reduce press noise. The resilient stop block replaces the conventional solid stop block and comprises a metallic member having a longitudinal bore and vertically spaced overlying pairs of diametrically opposed angularly oriented segmental slots extending inwardly through the sides of the block into the bore. The resilient stop block is compressable by the overlying solid stop block as the ram approaches the press bed.

Abstract: A hydraulic shock absorber having an outer tube which is closed at one end and open at the other end. An inner tube, having a plurality of metering orifices, and having a closed inner end and an open end, is mounted in the outer tube with its closed end against the closed end of the outer tube. A meter tube, having a plurality of metering openings, is rotatably mounted above the inner tube. The inner tube is retained in its longitudinal operative position by the meter tube, a rotatable retainer member, and a wave washer. A locking pin retains the inner tube against rotation. The inner tube, meter tube, and the rotatable retainer member are all assembled into the outer tube through the open end of the outer tube, and they are retained in the outer tube by a retainer member. A meter tube adjusting ring is rotatably mounted on the outer tube, and it is connected to the meter tube for adjusting the position of the metering holes in the meter tube relative to the metering orifices in the inner tube.

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: The invention relates to a machine for processing metal in sheet or plate form, and especially for bending metal sheets, which includes a machine frame, a table base and a ram vertically displaceable in relation to the table base. An upper tool is mounted on the ram and a lower tool cooperating therewith is disposed on the table base over the U section filled with oil with the sheet therebetween, these two tools bending the metal sheet. One of the tools is supported by a compliant support member for the tool. The compliant support member supporting the tool comprises a plurality of individual elements which are disposed tightly besides each other in the oil in the U section and are independently displaceable in a vertical direction so that, in operation, only those elements are displaced towards the supporting means on which the work sheet rests.

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.

Abstract: A spring unit comprising spring means, a cage for the spring means, and means to control the path of movement of the spring means within the cage having in association therewith means to apply a required pre-load on the spring means within the cage.In preferred embodiments of the caged spring assemblies, the open spaces between the coils of a contained spring are reduced to a dimension less than that of the thickness of the coils themselves. This prevents the coils from winding or screwing and from materially affecting the prescribed pre-load in event of spring breakage.