Abstract: A load-applying device of a press-forming die includes a rod which includes a first end, a second end, and a flange, a lamination coned disc spring in which a plurality of coned disc springs having a center hole, to which the first end of the rod is inserted, are laminated, a first plate which includes a first through hole to which the first end of the rod is inserted and abuts the lamination coned disc spring, a second plate which includes a second through hole to which the second end of the rod is inserted and abuts the flange; and a gap fixing member which is detachably provided between the first plate and the second plate and fixes a gap between the first plate and the second plate so as to maintain the gap by which the lamination coned disc spring biases the flange to the second plate. The second end and the first plate relatively move in a mutually approaching direction during press-forming, and the lamination coned disc spring is compressed.

Abstract: The invention provides an aerocushion assembly in a power press having a frame. The power press includes a shape assembly; a shaft communicating with the shape assembly; a cushion assembly communicating with at least one of the shaft and the shape assembly, the cushion assembly preventing at least one of off-center loading of the shaft or deflection of the shaft during movement thereof; a snubbing assembly communicating with at least the shaft; and an adjustment assembly communicating with the shaft and adjusts a stroke length.

Abstract: In the die cushion device, a shock absorber device relieves shock between a cushion pad and a support section. The shock absorber device includes a damping section and an elastic section. The damping section generates reaction force in accordance with the relative speed of the cushion pad with respect to the support section. The elastic section generates reaction force in accordance with the relative displacement of the cushion pad with respect to the support section. The controller section controls a servomotor so that a speed difference between the speed of the slide member and the speed of the support section is set to be a predetermined target speed difference value that changes over time.

Abstract: A combination oil/gas spring includes a first hollow casing, a piston capable of fluid-tightly sliding within the casing, a rod connected rigidly with an end portion thereof to a central portion of the piston, a first chamber containing an actuating rod provided inside the casing, a second sealed chamber provided within the same casing on the opposite side of the piston, a mass of hydraulic fluid filling the second sealed chamber, a second hollow casing and a respective second piston provided to slide therewithin, a first conduit connecting the interior of the second sealed chamber with the interior of the second hollow casing, a first valve connected to the first conduit and adapted to selectively open and close it, a second conduit being provided to connect an expansion vessel to the first conduit at a position upstream of the first valve, and a second valve being provided on the second conduit.

Abstract: A pressing machine 1 includes: a bed 6 on which a die-cushion device 10 is provided; and a bolster 51 provided on the bed 6. The bed 6 has an inner space 61 in which a die-cushion pad 13 of the die-cushion device 10 is lifted up and down. A supporting portion 63 penetrating the die-cushion pad 13 in a lifting direction and supporting a lower surface of the bolster 51 via a carrier 52 is provided in the inner space 61. With this arrangement, since the bolster 51 is supported by the supporting portion 63, the bolster 51 can be prevented from being flexed during a press forming operation, whereby a highly accurate press forming operation can be realized. In addition, since the supporting portion 63 penetrates the die-cushion pad 13, unlike conventional arrangements, the die-cushion pad 13 does not need to be divided, whereby a complication of the arrangement can be avoided.

Abstract: A die cushion pad 13 is divided into four small pads 15 and a large pad 16. With this arrangement, a load applied to an action point of each of the small pads 15 can be equalized by the large pad 16, and an overturning moment arising between the action point and a reaction force point that equates the center of the small pad 15 can be canceled, thereby preventing flexure of the small pad 15. Accordingly, since flexure of the cushion pin and the like can be prevented, there is no risk that the cushion pin is frictioned against the penetrating hole of a bolster, and the lifting operation can be smoothly performed, whereby a higher-accuracy pressing forming operation can be realized.

Abstract: A die cushion device is comprised of die cushion modules which are independently movable and unitized. The individual die cushion modules are provided with a cushion pad, a servomotor, a power transmission mechanism, a power conversion mechanism and a guide member. By configuring in this way, the design of the die cushion is facilitated, a drive mechanism of the die cushion becomes compact, and the number of types of parts used is decreased.

Abstract: An elastic member is disposed on a load supporting device such as cushion pins and wear plates, which are placed between at least a workpiece and a die cushion pad and transfer a load applied to the work to the die cushion pad, to support the load. The load supporting device is disposed in two or more on the die cushion pad to realize equalization of the load applied to a die cushion. Thus, use of a conventional large-scale hydraulic circuit is eliminated, and the device can be simplified. Also, the press machine can be produced at a low cost.

Abstract: A high-pressure, inert gas cushion assembly for the ram or bolster of a metal stamping press includes a manifold having fluid-flow passages defined therein, along with a plurality of cylinder mounting locations each in communication with at least one of the fluid-flow passages. A plurality of cushion cylinders are located respectively in the cylinder mounting locations. Each cylinder includes a body having an inner wall that defines a bore of diameter D. A piston is located in the bore and includes opposite inner and outer faces, wherein the outer face is oriented outwardly relative to the bore and manifold. A fluid seal is supported on the piston and is slidably engaged with the wall defining the bore. One or more bearings are supported on the piston and slidably engaged with the inner wall that defines the bore. The bearing(s) support the piston slidably in the bore for reciprocal sliding movement between extended and retracted positions.

Abstract: A gas spring comprising a cylinder body filled with compressed gas and an upright rod passing through a rod side end wall member of the cylinder body. By supporting a main shaft unit with the gas spring, the load on a vertical displacement mechanism is reduced. A pair of upper and lower ring-shaped seal members, which seal between the rod end wall member and the rod, are provided inside the rod wall member. Ring-shaped oil filling chambers are formed in between the ring-shaped seal members and between the rod end wall member and the rod. An oil filling mechanism fills the oil filling chambers with lubrication oil.

Abstract: A cushion assembly includes a lower end wall which is at least partially enclosed by a tubular cylindrical outer wall. An upper end wall is also partially enclosed by the outer wall. A tubular cylindrical inner wall extends between recesses in the lower end wall and the upper end wall. A piston is disposed within the inner wall and is movable along the inner wall toward the upper end wall under the influence of gas pressure. The piston is movable along the inner wall toward the lower end wall of the influence of force applied against the piston during operation of a press. A passage is formed between an end portion of the inner wall and the lower end wall to conduct a flow of lubrication liquid and gas to lubricate the piston.

Abstract: A fluid pressure cylinder with pressure intensifying function, has an oil-filled hydraulic pressure cylinder which is filled with oil and tightly sealed. A gas-filled gas spring is charged with gas and tightly sealed. By means of gas spring, oil in oil chamber of hydraulic pressure cylinder is pressurized to a pressure level higher than the gas pressure in gas actuating chamber of gas spring. This results in a strong pushing force being generated via output piston of hydraulic pressure cylinder.

Abstract: Fluid pressure cylinder 1 with pressure intensifying function, consisting of oil-filled hydraulic pressure cylinder 2 which is filled with oil L and tightly sealed and gas-filled gas spring 3 which is charged with gas G and tightly sealed, wherein, by means of gas spring 3, oil L in oil chamber 11 of hydraulic pressure cylinder 2 is pressurized to a pressure level higher than the gas pressure in gas actuating chamber 21 of gas spring 3 and a strong pushing force is generated via output piston 12 of hydraulic pressure cylinder 2.

Abstract: A gas spring includes an outer tube; a base plate; a head plate; an inner tube mounted to extend between the head plate and the base plate; a piston/rod assembly mounted to reciprocate vertically in the inner tube between a retracted, compressed position and an extended, rest position; a valve ring coaxially mounted around the rod to reciprocate between the main piston and head plate; a primary gas chamber; a relief chamber; seals for preventing fluid flow from the primary and relief chambers; a passageway providing communication between the primary gas chamber and relief chamber; and, valve apparatus for controlling fluid flow between the primary and relief chambers. The valve apparatus operates to open and close the fluid flow as a function of the position and direction of travel of the piston/rod assembly.

Abstract: A gas spring includes an outer tube; a base plate; a head plate; an inner tube mounted to extend between the head plate and the base plate; a piston/rod assembly mounted to reciprocate vertically in the inner tube between a retracted, compressed position and an extended, rest position; a valve ring coaxially mounted around the rod to reciprocate between the main piston and head plate; a primary gas chamber; a relief chamber; seals for preventing fluid flow from the primary and relief chambers; a passageway providing communication between the primary gas chamber and relief chamber; and, valve apparatus for controlling fluid flow between the primary and relief chambers. The valve apparatus operates to open and close the fluid flow as a function of the position and direction of travel of the piston/rod assembly.

Abstract: A fluid spring assembly. The spring assembly preferably includes a body that slidably supports a piston that is attached to a piston rod. The piston serves to define a fluid chamber within the body that is charged with a pressurized fluid medium. The piston is retained within the body by a rigid retainer member. A biasing member is provided between the retaining member and the piston for resisting the force generated by the fluid medium within the fluid chamber.

Abstract: A sleeve-type gas spring for a turret indexing press has an annular piston operably associated with a punch tool to reciprocate therewith and defining in part an annular gas chamber constructed to receive a gas under pressure. As the punch tool and piston are driven to their extended position by a press ram or some such other power device, the volume of the gas chamber decreases thereby increasing the pressure within the gas chamber such that when the ram is retracted, the pressure of the gas acting on the piston displaces the piston and the punch tool to their retracted positions. The force acting to retract the piston and the punch is dependent on the initial pressure of the gas within the gas chamber and the change in volume of the gas chamber as the punch tool and piston are extended.

Abstract: A gas spring with a first gas chamber communicated with a second gas chamber through a calibrated orifice to control the rate of return of gas from the first chamber to the second chamber to thereby control the rate at which a piston rod of the cylinder returns to its extended position. Desirably, the rate of return of the piston rod to its extended position can be made slow enough to prevent damage to a die stamped part as the gas spring lifts the part from a lower die half. The gas spring composite shell is preferably formed of and contains materials which are highly thermally conductive and define the return passage to prevent the gas spring from becoming overheated and to permit an increased number of cycles to be completed in a given period of time.

Abstract: A plurality of die cylinders adapted to contain gas under pressure are mounted on a manifold. Each cylinder comprising a cylinder body having an axially inner cylinder portion and an axially outer cylinder portion. A piston has an axially inner end portion extending into the inner cylinder portion and an axially outer end portion surrounded by the outer cylinder portion. A seal is provided between the inner end portion of the piston and the inner cylinder portion. There is a removable sealing cartridge between the outer end portion of the piston and the outer cylinder portion. A snap ring removably retains the cartridge on a shoulder between the inner and outer cylinder portions. The piston is capable of full axially outward retraction and separation from the cylinder when the cartridge is removed. The cylinder is free of any obstruction which would interfere with the axially outward retraction and separation of the piston when the cartridge is removed.

Abstract: A self-lubricating cylinder assembly for use in a press operable in an upright orientation and in an inverted orientation. The cylinder assembly contains a working fluid under pressure and lubricating oil. The cylinder assembly includes a cylinder body that has sidewalls that terminate in an opening at a first end and an end wall at a second end. The cylinder assembly further includes an interior wall assembly that connects to the cylinder body and has walls that extend within the cylinder body to the end wall. The wall assembly walls are preferably formed of a cylinder liner in connection with an insert. The cylinder liner has a piston mounted for reciprocal motion therebetween. A variable volume wall assembly space is defined as a space between the piston, the wall assembly walls and the housing end wall. An expansion reservoir is defined as a space between the side walls of the cylinder body, the wall assembly walls and the cylinder body end wall.

Abstract: In a vibration dampening support arrangement for supporting a component on a support structure such that it is removable only in a predetermined direction of removal, a projection extends from the support structure at an angle .alpha. of 12.degree. to 60.degree. with respect to the direction of removal and an elastic element is disposed on the projection in form-locking engagement with the component in the predetermined direction of removal but is unreleasably held in any other direction.

Abstract: A gas spring with an elongate tubular casing having a chamber for containing a gas under pressure therein. The casing has an opening at one end and an annular groove around the outer circumference. A piston rod projects from the casing through the opening and is connected to a piston disposed within the chamber for compressing the gas therein. A mounting sleeve is telescoped over the casing and has exterior threads thereon. The sleeve has an internal annular groove which coincides with the groove in the casing forming a passage between the sleeve and the casing. The sleeve is secured to the casing by a lock ring formed in the passage by injecting a resin into the passage and allowing it to cool and solidify. Holes are formed through the sleeve opening into the passage. Some permit resin to be injected into the passage through the holes and some permit resin to flow from the passage into the holes.

Abstract: A gas cylinder element having a replenishable lubrication means provided in the piston rod guide bushing. The gas cylinder element has an extended life expectancy and reduced manufacturing cost.

Abstract: Disclosed is a spring device which, during use in co-action with a deep-drawing device, is capable of causing the blank-holder pressure to decrease in proportion to the remaining material. The spring device holds substantially constant the blank-holder force per unit of surface area on the non-deformed material and is considered a "degressive" spring wherein the reaction force exerted by the spring decreases as the displacement between the ends of the spring increases.

Abstract: The present invention relates to gas cylinder springs and, more particularly, to gas cylinder springs which receive gas from a manifold into which the gas cylinders are threaded. The invention specifically relates to a way of automatically and in a nonmechanical manner expel atmospheric pressure from the gas spring. The piston rod of the gas spring is tapered slightly to provide a pocket into which atmospheric pressure can collect and be expelled around the gas spring seals on each stroke of the piston rod.

Abstract: A self-contained gas spring that has low heat generation characteristics and is easy to manufacture and maintain. The spring includes a bearing and seal assembly that is easy to remove from the cylinder body of the spring. The assembly includes an annular bearing for guiding the piston rod, the bearing is press fit within a bearing cap and, an end cap threaded in to the cylinder body. The end cap includes an annular seal surrounding and tightly engaging the piston rod of the gas spring. The end cap engages the bearing cap when the end cap is fully threaded into the cylinder body to retain the bearing cap within the cylinder body. The seal is formed of two materials, one very flexible, the other very rigid. The gas spring also has a unique piston head that has a hexagonal periphery with upwardly angled sides.

Abstract: A gas cylinder for use in die systems for forming lightweight parts. In one form, the cylinder forms a self contained gas spring which is interchangeable with a coil spring that is constructed such that it is not adversely affected by the deleterious effects of oil and other contaminants. The gas cylinder comprises a one-piece cylindrical upper body having a base wall and a peripheral wall and a hollow rod extending upwardly into the cylindrical body such that the upper body completely encircles and encloses the upper end of the rod. The rod has a base having an outer diameter greater than the diameter of the rod. The peripheral wall of the cylinder and the outer diameter of the base have substantially the same diameter such that the cylinder can be positioned in a recess of a press or die in place of a coil spring. The cylindrical body and rod include interengaging portions limiting axially outwardly movement of the cylinder relative to the rod.

Abstract: A filler valve and fitting for a gas spring. The filler valve has a body slidably received in a cavity in a housing and movable between a first sealed position for retaining gas within a gas chamber in the spring and a second position for bleeding gas from the chamber to relieve pressure within the chamber. For charging the chamber with gas, a core valve is carried by the body. Preferably, the housing has an exterior configuration and size of a standard flow-through type coupling having a pair of exteriorly threaded portions separated by a central portion with parallel flats constructed and arranged for engagement by a tool to install and remove the housing. The body has opposed effective areas with the effective area adjacent an inlet in the housing being greater than the effective area adjacent the outlet for enabling gas within the chamber to be compressed to a pressure much greater than the supply line pressure.

Abstract: An apparatus to cushion movement of a member in a machine includes a piston which divides a cylinder into upper and lower variable volume chambers. A body of lubricating liquid is held in a chamber in the piston. Lubricating liquid is conducted from the chamber in the piston to an annular space between upper and lower seals on a head portion of the piston. During reciprocation of the piston, the lubricating liquid engages the inner side surface of the cylinder. In addition, the lubricating liquid conducts heat away from the cylinder. Fluid pressure is applied against upper side surface of the body of lubricating liquid in the piston chamber by gas pressure conducted from a chamber of the cylinder. During assembly of the apparatus, the piston is inserted part way into the cylinder and a space between seals on the piston is partially filled with lubricating liquid. The piston, with the lubricating liquid between the seals, is fully inserted into the cylinder.

Abstract: A self contained gas spring comprising a cylindrical housing having a closed end, an open end and a cylindrical bore. A cylindrical sleeve extends into the bore of the housing. The sleeve has at least a portion thereof forming an internal cylindrical surface. A piston rod extends through an opening in the sleeve and has a piston contacting the cylindrical surface. A portion of the sleeve defines a first space between the sleeve and the bore of the housing. The first space communicates with a second space between the piston end of the piston rod and the closed end of the housing. A charging valve is provided in the closed end of said housing for charging the space at the piston end of said piston rod and the space between the sleeve and the housing with gas under pressure. A third axial space is provided between the cylindrical surface on the sleeve and the piston rod above the piston and is isolated from the first space and second space.

Abstract: A high pressure die cylinder and manifold system including a plurality of die cylinders mounted on a manifold. Each die cylinder includes a cylinder body in which a piston rod and a piston is positioned for limited relative movement with respect to the cylinder body. A cup shaped piston sealing ring is mounted on the cylinder body for engagement with the piston rod and a cup shaped sealing ring is mounted on the piston for engagement with the cylinder body. A lubricant metering ring is mounted on the piston intermediate the sealing rings and the piston has a lubricant chamber that communicates with circumferentially spaced openings in the lubricant metering ring for delivering lubricant to the exterior of the sealing ring.

Abstract: A gas spring assembly includes a cylindrical tube, a piston slidable within the tube and defining a gas pressure chamber, a rod extending from the piston through one end of the tube, and a seal assembly including an axially compressible, consumable seal for preventing escape of gas between the rod and the tube. A stop formed in the inner wall of the tube is adapted to engage the piston to limit the extension of the rod to a constant, maximum value, regardless of axial compression and consumption of the seal. The seal assembly is disposed between the stop and one end of the tube, opposite the piston, and includes gas passageway allowing pressurized gas to act on one end of the seal assembly to thereby bias the seal assembly toward one end of the tube.

Abstract: An apparatus and method for use in cushioning movement of a member in a press includes a cushion assembly having a piston and cylinder which are movable relative to each other against the influence of fluid pressure to cushion movement of the member. A flexible diaphragm retains a body of lubricant between an inner side of the diaphragm and the piston. The body of lubricant lubricates a seal between the piston and the cylinder. Fluid pressure is applied against the outer side of the diaphragm to oppose movement of the piston during operation of the press from the open condition to the closed condition. The piston is movable relative to the cylinder, under the influence of the fluid pressure applied against the outer side of the diaphragm and transmitted to the piston, during operation of the press from the closed condition to the open condition. The piston and diaphragm are spaced apart with the body of lubricant filling the space between the piston and diaphragm.

Abstract: A self contained gas spring which is interchangeable with a coil spring that is constructed such that it is not adversely affected by the deleterious effects of oil and other contaminants. The gas spring comprises a one-piece cylindrical upper body having a base wall and a peripheral wall and a rod extending upwardly into the cylindrical body such that the upper body completely encircles and encloses the upper end of the rod. The rod has a base and the outer diameter of the peripheral wall of the cylinder and the outer diameter of the base have substantially the same diameter such that the cylinder can be positioned in a recess of a press or die in place of a coil spring. The cylindrical body and rod include interengaging portions limiting axially outwardly movement of the cylinder relative to the rod.

Abstract: A self contained gas spring comprising a housing having a closed end and an open end, and a cylindrical bore. A cylindrical sleeve is inserted into the bore of the housing. The sleeve has at least a portion thereof forming an internal cylindrical surface. A piston rod has a piston within the cylindrical surface. The sleeve defines a space between the sleeve and the bore of the housing. This space communicates with the space of said cylindrical surface at the piston end of the piston rod. A charging valve is provided in the closed end of said housing for charging the space at the piston end of said piston rod and the space between the sleeve and the housing with gas under pressure. Preferably, the die cylinder includes sufficient volumetric space such that the pressures in the self contained gas spring do not increase substantially during the movement of the piston within the cylinder.

Abstract: A closed type cylinder unit, instead of the open-to-atmosphere type cylinder unit of conventional equipment forms part of the die cushion apparatus. Based on the principle that the die cushion capability by the closed type cylinder unit is determined by the differential pressure between the lower chamber pressure and the upper chamber pressure, the differential pressure is controlled in such manner that the lower chamber and the upper chamber communicate with each other through a check valve, which is opened when the differential pressure exceeds a preset differential pressure value. As the upper and lower chambers communicate through a shut-off valve, which hinders the excessive increase of the upper chamber pressure when the piston goes up. Further, the form of the check valve is changed for conveniently changing and adjusting the die cushion apparatus during press fabrication.

Abstract: A compressed gas and a liquid are contained in a cylinder. A liquid chamber containing the liquid and a gas chamber containing the gas are divided by a metallic bellows. The liquid chamber is situated on the side of an open end of the cylinder. A rod is inserted in the cylinder. A sealing assembly is provided at the open end of the cylinder. The sealing assembly has a bearing member at only one portion of the cylinder with respect to the axial direction thereof. A space extends throughout the circumference between the outer peripheral surface of the inner end of the rod and the inner peripheral surface of the cylinder. A seal device for sealing the liquid in the liquid chamber includes a seal ring intimately in contact with the outer peripheral surface of the rod and an elastomer ring provided on the outer peripheral surface side of the seal ring and capable of elastic deformation in the radial direction of the rod. The rod can swing within the range of an angle .theta.

Abstract: A gas spring comprising a cylindrical body having a base wall and an integral side wall with an open upper end defining a bore. The bore includes a lower cylindrical portion and an upper cylindrical portion of greater diameter than the lower cylindrical portion defining a shoulder. A piston of constant diameter is positioned in the bore and has a radial flange on its lower end with a wear bearing contacting the lower portion of the bore. An annular retainer is positioned on the shoulder and is adapted to be engaged by the flange on the piston. An annular end cap is threaded in the upper cylindrical portion of the bore and maintains the retainer against the shoulder. An annular lock nut is threaded in the upper portion of the bore and locks the end caps in position. Circumferentially spaced radial openings are provided adjacent the periphery of the lock nut for venting gas during disassembly if any gas remains. A charging valve and a rupture plug including pressure relief disc are provided in the base wall.

Abstract: The present invention relates to an arrangement for a gas spring (1). This comprises a cylinder (2) with a piston (3) capable of being displaced axially therein, which marks the boundary of an inner space (4) of the cylinder (2) filled with a compressible gas-oil mixture. The space (4) varies in volume in accordance with a force (F) acting upon a piston rod connected to the piston. The invention is characterized in that the inner space is so arranged as to communicate via an openable and closable valve (13) with a closed space (10). The arrangement includes a control device (12) for actuating the valve (13), which control device is so arranged as to close the valve (13) once the piston (3) has moved past a predetermined axial position in the cylinder (2), and as to open it at a predetermined time after the moment of closing.

Abstract: A single action cylinder is used with a machine. The machine has a first part and a second part having reciprocating motion relative to each other. The single action cylinder affects the reciprocation between the first and second parts. The cylinder includes a base adapted for attachment to one of said parts. The cylinder includes a plurality of open ended longitudinally extendable resilient actuators stacked one above the other. A first actuator of said actuators has one end connected to the base. Each of the actuators is interconnected to an adjacent actuator to allow a fluid to flow between the actuators. A second actuator of the actuators has one end connected to an apparatus for attaching the second actuator to the other of the parts. An elongated guide is connected to one of the actuators to limit movement of that actuator in a direction transverse to the length of the guide.

Abstract: A pneumatic-hydraulic booster type driving device for the cushion-knockout mechanism associated with the slide of a press-machine serves to stably hold down a work plate such as a printed board and the like while performing a cushion operation at the time of a pressing stroke and serves to knock out the work plate after the pressing stroke in the press-machine. In the driving device, a pneumatic-hydraulic booster is connected through a pressure oil supply and discharge means to a hydraulic actuation chamber of a cushion cylinder provided in the slide of the press-machine, and the pressure oil supply and discharge means comprises a valve chamber within a valve casing and a knockout actuator which is fixedly secured to the valve casing so as to perform the valve opening operation of the valve unit.

Abstract: A plate bending machine for performing precise bending operations includes a machine pedestal having two opposite side sections, a guide member provided at each side section of the machine pedestal, and a vertically movable guide post supported by the guide members. A lower bending tool is supported by the machine pedestal and an upper table has two side sections, each supported by the guide posts. An upper bending tool is supported by the upper table and is adapted to move vertically with the upper table to operate in cooperation with the lower bending tool. An eccentric shaft is supported in a freely rotatable manner on the machine pedestal and has an eccentric section with which the guide post is engaged at its lower section, wherein there is play between the guidepost and the eccentric section. A play removing device is mounted on the machine pedestal, for removing the play between the guide post and the eccentric section.

Abstract: A power press used for metal working is provided with a cushioning system. During the operation of a press, abrupt changes in the velocity of certain moving parts of the press may damage or cause rapid wear to parts. The present invention utilizes pneumatic bellows actuators. A hydraulic snubber and snubber-intensifier having closed systems are in combination with a pneumatic bellows actuated die cushion. The snubber has a piston within a cylinder assembly. During the upward stroke of the ram of the press, the movable plate of the die cushion is held back by the piston so as to prevent a damaging impact on the movable die parts and workpiece supported by an air cushion. Fluid is allowed to flow from the top of the piston through a flow valve to return to a reservoir within the die cushion or to the bottom of the cylinder.

Abstract: A pneumatic shock absorber used primarily as a die spring includes a piston formed with a base and an upstanding cylindrical body provided with an internal fluid reservoir. An outer housing is mounted on the base and extends about the cylindrical body. An inner housing is axially telescopically mounted for sliding movements within the outer housing. A flexible sleeve is enclosed at one end by a sealing cap and is sealingly connected at its outer end to the exterior of the piston body forming a fluid chamber therein which communicates with the fluid reservoir of the piston. An opening is formed in the piston body to fill the reservoir and chamber with a high pressure fluid which places the inner housing in an expanded position by the end cap pressing against an end wall of the inner housing upon axial expansion of the sleeve. Rolled end flanges formed on the housings engage each other to stop the movement of the inner housing at the expanded position.

Abstract: A gas spring with a piston rod slidably received in a cylinder which defines a chamber in which a gas is compressed when the rod is forced into the cylinder. The gas spring can be operated with either an external source of gas or as a precharged and self-contained unit by changing first and second valves assemblies either of which can be installed in the same cavity in the cylinder. If desired, a check valve can control the bleeding of gas under pressure in the cylinder back to the entrance of the cavity containing one of the valve assemblies through which the cylinder is filled with gas.

Abstract: The present invention relates to a pneumatic press counterbalance and cushion construction. The press counterbalance holds certain parts of a press in the same relative engagement during the return stroke of a ram of the press as during the power stroke of that ram. The counterbalance includes a fixed plate adapted for connection to a part of the press. A pneumatic bellows has one end connected to the fixed plate. A movable plate is connected to the opposite end of the pneumatic bellows. A connector rod is connected to the movable plate and to another part of the press which part is movable relative to the part to which the fixed plate is connected. The pneumatic cushion includes a resilient bellows having one end connected to the fixed plate. A bellows connector is connected to the other end of the bellows. A second bellows has one end connected to the bellows and the other end connected to the movable plate.

Abstract: A self-lubricating die cylinder assembly is provided containing a cylinder, piston, expansion reservoir and working chamber. A lubricating oil recirculation means is provided to transport oil between the working chamber and the expansion reservoir during each of the piston strokes. A flow restrictor is provided to create a pressure differential between the two chambers during movement of the piston thus creating a jet mixture of compressible working fluid and lubricating oil spraying onto the walls of the cylinder.

Abstract: A die cushion construction for use in a press is the subject matter of the present invention. The instant die cushion construction includes a fixed plate connected to the press. A resilient cushion actuator has one end sealingly connected to the fixed plate. The resilient cushion actuator has an opposite end sealingly connected to a movable plate. The movable plate is adapted for connection to a portion of a die mounted in the press. A resilient snubber actuator has one end fixed relative to the fixed plate. The snubber actuator has an opposite movable end connected to the movable plate for affecting the rate of movement of the movable plate and a portion of the die. The snubber actuator is connected to means for allowing fluid to flow into the snubber actuator when the movable plate moves toward the snubber actuator.

Abstract: An improved snubber apparatus for an air cushion within a forming press is provided. A floating piston is mounted within the air cushion and defines a snubbing chamber. As the air cushion returns to its top stroke position after yieldably deforming to cushion a member within the forming press, a movable piston within the air cushion contacts the floating piston, forcing it to move in the direction reducing the volume of the snubbing chamber. A check valve is provided between a cushion chamber and the snubbing chamber which maintains the pressure in the snubbing chamber at a minimum equivalent to the pressure in the cushion chamber. As the volume of the snubbing chamber is reduced, the air trapped within is rapidly compressed to a value snubbing the motion of the air cushion. The snubber valve is provided communicating with the snubbing chamber and maintained in a closed position by the air pressure within the cushion chamber.

Abstract: For use in a system comprising a source of pressurized fluid and a plurality of lines extending to a plurality of gas springs, a gas spring comprising a cylindrical body with a bore, a piston rod positioned in the body and having an end projecting beyond one end of the body, a base closing the other end of the body, the cylindrical body and piston rod interengaging one another to limit relative outward movement of the piston rod with respect to the body. The gas spring includes a radial inlet through the wall of the cylindrical body into the base. A one-way valve is positioned in the base within the inlet and an axial inlet pressure passage extends from the outlet end of the valve to the interior of the cylinder. A radial bore is provided in the base and communicates at one end through an axial pressure relief passage to the interior of the cylinder.