Abstract: A delay return gas spring including a piston at least partially received in a cylinder for reciprocation between extended and compressed positions over a cycle including a compression stroke and a return stroke. A seal disposed between the cylinder and the piston separates a primary chamber on one side of the seal from a secondary chamber on another side of the seal during a portion of the cycle. A passage communicates with the secondary chamber and with the primary chamber. The seal is relatively movable between an open position permitting free flow of gas through the passage to a closed position at least partially restricting gas flow through the passage so as to permit gas in the secondary chamber to be compressed in response to movement of the piston toward its extended position, thereby reducing a net return force on the piston and decreasing a velocity of the piston.

Abstract: A gas spring for providing a smooth and generally gradual load distribution between interrelated parts of a press has a casing defining at least in part a gas chamber. A housing is received at least in part in the casing. The housing has a through bore sized for receipt of the piston rod therein for reciprocation between extended and retracted positions. A piston retainer is attached for conjoint movement with the piston rod. An end of the housing flexes between a compressed position when the piston retainer abuts the housing as the piston rod moves toward its extended position and an uncompressed position when the piston retainer moves toward its retracted position and out of engagement with the housing.

Abstract: In at least one embodiment, a gas spring includes a casing having an inner surface defining in part a gas chamber, a piston rod and a seal. The piston rod is received at least partially in the casing for reciprocation along an axis between extended and retracted positions. The piston rod has an internal cavity defining a hollow space, a stop and a rod guide disposed adjacent to the inner surface of the casing to guide the reciprocation of the piston rod at least in part. The seal generally is provided between the piston rod and the casing to prevent gas leakage from the gas chamber.

Abstract: A hydraulically-operated press-driven tool actuation system includes a press-driven hydraulic power device and/or a hydraulically-powered tool actuator. In the tool actuator, at least two pistons are carried by a housing, and at least one return device is carried by the housing laterally inboard of the pistons. In the power device, a pump includes a piston disposed in a pump cylinder for pressurizing hydraulic fluid therein. An accumulator is in fluid communication with the pump cylinder, and includes a piston disposed in an accumulator cylinder that houses hydraulic fluid on one side of the piston. A body supports the pump and accumulator thereon and is in fluid communication between the pump and accumulator cylinders. The body includes a pressure relief valve downstream of the pump cylinder and upstream of the accumulator cylinder, and a check valve downstream of the accumulator cylinder and upstream of the pump cylinder.

Abstract: A pressure indicating device includes a case including a gas passage, and a movable indicator carried by the case. The indicator has an end in fluid communication with the gas passage and an indicator end projectable out of a portion of the case when pressure in the gas passage is at least a predetermined minimum pressure. A spring may retract the indicator when pressure in the gas passage is below the predetermined minimum pressure.

Abstract: A gas spring with a piston rod assembly received for movement between retracted and extended positions in a casing defining a main gas chamber. The piston rod assembly when in its extended position cooperates with a portion of its retainer and the casing to at least in part provide a secondary gas chamber separate from the main gas chamber and having gas trapped therein at a higher pressure than that of gas in the main gas chamber to reduce the force required to initially move the piston rod assembly from its fully extended position toward its retracted position.

Abstract: A reaction device for forming equipment includes a housing having a mount adapted to be connected to a forming die and a casing carried by the mount. A lift rod is disposed at least partially on the housing for movement relative to the house between extended and retracted positions. The lift rod has a first end disposed in the housing, a second end and a passage extending through the lift rod between its ends. An adapter is connected to the lift rod within the passage and is adapted to be coupled to a lift bar of the forming equipment. A biasing member is disposed between the lift rod and the housing to yieldably bias the lift rod to its extended position.

Abstract: A tool to install a retaining ring into a groove in a cylinder has a handle lever which carries an adjustable gripper constructed to engage the cylinder and a compressing lever constructed to engage a portion of the retaining ring with the compressing lever pivotally and slidably connected to the handle lever permitting relative movement between the two levers. The connection between the handle lever and the compressing lever permits them to be separated and joined together in a fashion that facilitates engaging and compressing the retaining ring for insertion into the cylinder.

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 spring having a main gas chamber, a secondary gas chamber and sealing surfaces which, during a portion of the stroke of the piston rod, define a gas tight seal between them to provide two separate gas chambers each providing a force acting on the piston rod in opposed directions to each other to reduce the net force on the piston rod. When the piston rod is near its fully extended position the sealing surfaces provide the gas tight seal and the net force on the piston rod is minimal and in the direction to move the piston rod to its fully extended position. Thus, until the cooperating surfaces are displaced to terminate the gas tight seal, only a slight force is required to initially move the piston rod from its fully extended position. This greatly reduces the impulse or impact force imparted to a press ram upon initial actuation of the fully extended piston rod. A second seal assembly may also be provided which controls the rate at which the piston rod assembly returns to its fully extended position.

Abstract: For a hydraulically actuated device a hydraulic power cylinder with an actuator slidably received for reciprocation within the cylinder and a piston slidably received for reciprocation within a sleeve of the actuator and defining a gas chamber on one side of the piston and a hydraulic fluid chamber on the other side of the piston so that the maximum pressure in the hydraulic fluid chamber is limited as a function of the force of compressed gas in the gas chamber acting on the piston. In this way, the maximum system pressure is a function of and substantially corresponds to the pressure of the compressed gas within the gas chamber and acting on the piston. Desirably, the pressure of the compressed gas in the gas chamber can be readily changed to change the maximum hydraulic fluid pressure.

Abstract: A gas spring has a casing defining a chamber constructed to be filled with a gas under pressure, a piston rod received in the chamber for reciprocation between extended and retracted positions and having a free end projecting beyond the casing, a gas fill passage formed in the casing and through which pressurized gas is admitted into the chamber and a filler valve disposed in the fill passage to selectively permit the flow of gas through the fill passage. The filler valve has a body with a passage formed therethrough, a valve seat defined in the passage between opposed ends of the body and a poppet received in the passage and engageable with the valve seat to selectively permit gas flow through the filler valve and hence through the fill passage of the gas spring casing. The filler valve body preferably has mechanical threads formed in its exterior and constructed to be mated with complementary threads in the gas fill passage to firmly and releasably hold the filler valve within the fill passage.

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 tool to remove a retaining ring at least partially received in a groove of a cylinder has a handle lever constructed to engage the open end of the cylinder and a claw lever having a hooked end or claw constructed to be received at least partially underneath the retaining ring with the claw lever pivotally connected to the handle lever permitting relative movement between the two levers. The pivotal connection between the handle lever and claw lever permits them to be separated and joined together in a scissor-like fashion to facilitate engaging the claw with the retaining ring. When engaged with the retaining ring, the tool is pivoted about the cylinder to displace the claw and thereby displace the retaining ring inwardly and upwardly of the groove to remove it from the cylinder. The tool permits easy and non-destructive removal of the retaining ring and requires relatively low force and a relatively low level of skill to remove the retaining ring from the cylinder.

Abstract: A gas spring with a sealing and bearing assembly received within a casing of the gas spring adjacent to a rod slidably received through the assembly for axial reciprocation. The assembly has an annular retaining ring received within the casing, an annular bearing with a throughbore through which the rod reciprocates carried by the retaining ring, an annular retainer carried by the retaining ring downstream of the bearing, and a sealing member received within the retaining ring adjacent to the retainer and in firm engagement with the rod and retaining ring to provide a gas-tight seal between the rod and the retaining ring to prevent the escape of gas from the gas spring. The retainer preferably has a dovetail flange extending therefrom and the sealing ring has a complementarily shaped recess molded or press-fit onto the flange to attach the sealing ring to the retainer. The retainer is preferably firmly clamped to the retaining ring by rolling its upper edge over the retainer.

Abstract: A tool to remove a retaining ring at least partially received in a groove of a cylinder has a handle lever constructed to engage the open end of the cylinder and a claw lever having a hooked end or claw constructed to be received at least partially underneath the retaining ring with the claw lever pivotally connected to the handle lever permitting relative movement between the two levers. The pivotal connection between the handle lever and claw lever permits them to be separated and joined together in a scissor-like fashion to facilitate engaging the claw with the retaining ring. When engaged with the retaining ring, the tool is pivoted about the cylinder to displace the claw and thereby displace the retaining ring inwardly and upwardly of the groove to remove it from the cylinder. The tool permits easy and non-destructive removal of the retaining ring and requires relatively low force and a relatively low level of skill to safely remove the retaining ring from the cylinder.

Abstract: A gas spring with a filler block assembly defining the rear sealing wall of the gas chamber of the gas spring. The filler block assembly has an end cap with an internally threaded through passageway for filling the chamber with compressed gas. An externally threaded screw plug is threaded into the cap passageway and has an enlarged head portion with a conical sealing surface. An O-ring encircles the screw plug and is wedge-captured sealably between its sealing surface and a radial sealing surface on the cap front face. The screw plug and passageway threads are constructed and arranged to provide a gas chamber filling leakage path therebetween such that the gas spring chamber can be charged with pressurized nitrogen gas admitted into the rear end of the cap filling passageway with the screw plug and O-ring already installed in the cap in final operable position to function as a one-way check valve for admitting the pressurized gas to the spring chamber and to prevent egress of the gas therefrom.

Abstract: An array of a plurality of module blocks with a common through-passageway with a combined fluid coupling and mechanical connector fitting received in the passageway between each pair of adjacent blocks. The fitting has a swivel body rotatably retained by a flexible retaining wire on a main body with two static-type O-rings. The main body has external straight threads on one end and a hex head protrusion adjacent the other end. A fluid conducting through-passageway in the main body has an enlarged cylindrical counterbore open at the hex end and with a circular internal groove therein. A tangentially intersecting wire-insertion radial opening leads from an external surface of the hex head into this groove. The swivel body has external straight male threads at one end, a cylindrical shank at the other end and a fluid conducting through-passageway communicating at one end with the main body passageway and having a hex socket in the other passageway end.

Abstract: A hydraulic actuator for a hydraulically driven device has a hydraulic cylinder, a first piston slidably received for reciprocation within the cylinder and defining a hydraulic fluid chamber with the cylinder, a second piston slidably received for reciprocation within a cavity in an actuator rod connected to the first piston and defining a gas chamber on one side of the second piston and an accumulator chamber on the other side of the second piston. A passage formed in the first piston communicates the hydraulic chamber with the accumulator chamber and a pressure relief valve selectively permits hydraulic fluid flow through the passage from the hydraulic chamber to the accumulator chamber to limit the maximum pressure of the hydraulic fluid within the hydraulic chamber and the hydraulically driven device. Preferably, during normal operation of the actuator and the hydraulically driven device the pressure of the hydraulic fluid is less than that required to open the pressure relief valve.

Abstract: A gas spring that momentarily dwells in its retracted position after the retraction force is removed. The gas spring has a casing, a first piston received within the casing, a piston rod protruding from the casing and connected to the first piston, and a second piston received within the casing. A compressible gas is received within the casing between the second piston and the other end of the casing. A hydraulic fluid is received within the casing between the first and second pistons and between the first piston and the one end of the casing. A delay valve and a check valve carried by the first piston controllably transfer hydraulic fluid between the two fluid chambers, the delay valve causing the first piston and rod to dwell in the retracted position by delaying the free transfer of fluid between chambers.