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 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: 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.