Abstract: An adjustable installation includes a body and a member carried by the body for adjustment among a plurality of positions by movements substantially in tandem of two spaced-apart locations on the member. A controllable locking gas spring is coupled between the body and the member at one of the locations, and an emergency locking gas spring is coupled between the body and the member at the other of the locations. The emergency locking gas spring normally acts like a non-locking gas spring and is thus in a follower relationship to the controllable locking gas spring but is locked automatically in either of two ways, depending on its design. In some designs, the emergency locking gas spring locks when a force greater than a predetermined force is imposed on it. In other designs, the emergency locking gas spring is locked in response to a signal generated by an acceleration detector upon detection of an acceleration of the installation greater than a predetermined acceleration.

Abstract: An adjustable installation includes a body and a member carried by the body for adjustment among a plurality of positions by movements substantially in tandem of two spaced-apart locations on the member. A controllable locking gas spring is coupled between the body and the member at one of the locations, and an emergency locking gas spring is coupled between the body and the member at the other of the locations. The emergency locking gas spring normally acts like a non-locking gas spring and is thus in a follower relationship to the controllable locking gas spring but is locked automatically in either of two ways, depending on its design. In some designs, the emergency locking gas spring locks when a force greater than a predetermined force is imposed on it. In other designs, the emergency locking gas spring is locked in response to a signal generated by an acceleration detector upon detection of an acceleration of the installation greater than a predetermined acceleration.

Abstract: A gas spring has a single bypass across the piston that is controlled by a valve member of an elastomeric material, which restricts flow through the bypass when the gas spring is compressed (piston rod moving into the cylinder) and produces a pressure differential across the piston that varies inversely with temperature. The increasing force opposing compression of the gas spring due to the pressure differential across the bypass as the temperature of the gas spring, and thus the output force, decreases maintains the handle load more even over a range of temperatures. The elastomeric valve member has very little effect on the normal operation of the gas spring in the extension (rod moving out) mode.

Abstract: An adjustable installation includes a body and a member carried by the body for adjustment among a plurality of positions by movements substantially in tandem of two spaced-apart locations on the member. A controllable locking gas spring is coupled between the body and the member at one of the locations, and an emergency locking gas spring is coupled between the body and the member at the other of the locations. The emergency locking gas spring normally acts like a non-locking gas spring and is thus in a follower relationship to the controllable locking gas spring but is locked automatically in either of two ways, depending on its design. In some designs, the emergency locking gas spring locks when a force greater than a predetermined force is imposed on it. In other designs, the emergency locking gas spring is locked in response to a signal generated by an acceleration detector upon detection of an acceleration of the installation greater than a predetermined acceleration.

Abstract: A piston rod-cylinder assembly, such as a gas spring, includes a cylinder in which a piston rod is axially movable and connecting members on the cylinder and the piston rod for attachment of the assembly in use. The cylinder and an axial portion of the piston rod are covered by a shrink-wrap sleeve for corrosion protection and/or coloration. A lubricant layer is provided between the cylinder and the shrink-wrap sleeve adjacent one or both ends of the cylinder.

Abstract: A gas spring comprises a first bypass with a one-way valve that allows fluid to bypass the piston when the piston moves outward and a second bypass with a temperature-compensating spring-biased one-way valve that allows fluid to bypass the piston when the piston is pushed inward with a force exceeding the total of the force due to the gas pressure of the gas spring and the force required to open the spring-biased valve. Variations due to temperature changes in the force required to retract the gas spring are minimized.

Abstract: A plastic stand pipe designed for application to furniture such as a chair, to replace a metal stand pipe supporting a gas fluid spring which allows a seat to be raised and lowered as desired. The plastic stand pipe is attached to the chair base, and encloses the fluid spring which supports the seat. The inventive design relies on the combination of a novel structural configuration of the stand pipe inner working parts which support the fluid spring cylinder and use of appropriate plastic engineering materials to achieve the result allowing for replacement of the metal stand pipe. The structural configuration features a plurality of ribs formed on the inner wall of a plastic tubular member, such that the ribs contact the fluid spring cylinder and provide circumferential support. The end of each rib is formed with a support projection which is flexible, and the plurality of support projections form a floating support ring allowing for some freedom in the fluid spring movement from side to side at its top end.

Abstract: A gas spring comprises a first bypass with a one-way valve that allows fluid to bypass the piston when the piston moves outward, a second bypass with a spring-biassed valve that allows fluid to bypass the piston when the piston is pushed inward with a force exceeding the combined gas-spring and spring-biased valve forces, and a third bypass having a temperature-responsive valve that allows fluid to bypass the piston when the rod is pushed in but only when the temperature of the gas exceeds a selected level.

Abstract: Rattling of the piston against the tube in a gas spring due to transient lateral loads on the piston are inhibited by engagement of the base of the piston ring groove with internal projections of a serrated inner edge of the sealing ring. Assurance against seizure of the sealing ring to the piston and preservation of a minimum width of the face seal between the sealing ring and the ringland to ensure against leakage are provided.

Abstract: A gas spring-assisted counterbalance system for a closure member, e.g., the rear door of a hatchback automobile, includes a mechanical spring connected in series with a gas spring. The system is arranged so that the gas spring reaches its fully retracted position before the door is fully closed, after which the door is closed against the force of the mechanical spring. Longitudinal vibrations or short movements of the system which otherwise would impart undesired short stroke cycles to the gas spring are absorbed by the mechanical spring, thereby enhancing the operating lifetime of the gas spring.

Abstract: A temperature compensated gas spring having a sealed outer casing and a t located within the outer casing. A piston is located within the tube and a rod is attached to the piston extending out of the casing through one end thereof. A primary pressure source is located within the casing and the tube and acts against the piston to urge the rod out of the casing. A secondary pressure source is located within the casing and the tube and acts against the piston to urge the rod into the casing. The primary pressure created by the primary pressure source is greater than the secondary pressure created by the secondary pressure source, and the percent change of the secondary pressure with temperature variation is greater than the percent change of the primary pressure with the same temperature variation.

Abstract: A temperature compensated gas spring mechanism comprises a main gas spring energized by a pressure source that generates primary forces in excess of the selected design forces for the mechanism and a secondary gas spring energized by a second pressure source that generates forces opposed to those of the main gas spring and of magnitudes approximately equal to the excesses of the primary forces over the selected design forces, thereby a compensate to a substantial extent for changes in the primary pressure due to temperature variations.

Abstract: A mechanical locking device for restraining the piston rod of a gas spring n an extended position comprises a lock tube mounted on the piston rod coaxially with the cylinder and adapted to ride telescopingly over the cylinder during normal inward and outward movement of the piston rod. Apparatus is provided on the piston rod whereby the piston rod can be overextended, beyond its normal fully extended position, to permit the lock tube to move out of coaxial alignment with the cylinder; the end of the lock tube thereby abuts the end face of the cylinder and prevents inward movement of the piston rod.

Abstract: A gas spring, having a collapse safety feature operable in the event of psure loss, is provided, for use, for example, as a counterbalance for flaps or vertically adjustable structures. A movable partition is arranged between the piston and the head of the cylinder of the gas spring, and is exposed on one side to a closed gas chamber under pressure, while on the other side the gas volume effecting the extension force of the piston rod is present between the piston and the partition. In event of pressure loss in the gas volume on either side of the piston, the movable partition will meet the piston and act as a safety to prevent abrupt release or lowering of the object for which the gas spring is to serve as a counterbalance.

Abstract: A resilient support column for height-adjustable chairs or the like includes a piston-and-cylinder type pneumatic spring that is installable in and removable from the column by means of a retaining sleeve structure carried by the spring. The retaining sleeve is connected to the column through a threaded connection that permits quick one-step insertion of the combined sleeve-spring unit into the column, while thereafter affording the advantage of threaded adjustment within the column or threaded removal therefrom. A simple mechanical fastener holds the retaining sleeve in place on the pneumatic spring during shipment and/or assembly.

Abstract: A seal between a piston rod and a housing in which the piston reciprocates for preventing the escape of compressed fluid from the housing. A fixed sealing member engages the piston rod adjacent the housing wall, and a floating sealing member engages the piston rod at a location spaced from the fixed sealing member. A liquid is in the space between the sealing members.

Abstract: In the illustrative embodiments of the invention disclosed, the extension rce of a gas spring is controlled as a function of temperature by varying the volume of the working chamber entered by the piston rod, and thus the gas pressure within the working chamber, as a function of temperature.