Abstract: The invention relates to an arrangement for a gas spring. The arrangement comprises a cylinder (1). At its one end, this is delimited by a fixed end wall (2), and at its other end there is a first guide (3) sealed against the inner wall of the cylinder (1) and against a piston rod (4) capable of axial movement within the cylinder (1). The piston rod (4) has a second guide (8) mounted in such a way as to be capable of sliding against the inner wall. An annular piston (9) sealed against the inner wall and against the piston rod (4) is mounted on the piston rod (4) between the guides (3; 8) in such a way that it is free to slide. This divides the inner space of the cylinder (1) into a first and a second part space (12; 13). In an initial position, in which the gas spring is unaffected, there is present in the first part space (12) a pressure which is greater than the pressure present in the second part space (13).

Abstract: The invention relates to a degressive gas spring. This has two cylinder-piston units (1, 2), one of which is selected as a working spring (1) and the other as a slave spring (2), the cylinders (1a; 2b) and the ends of the piston rods (1b; 2b) of which are mutually operatively connected so that compression of the working spring (1) also brings about simultaneous compression of the slave spring (2). The piston rod (1b; 2b) of each spring unit (1; 2) is mounted in an end wall (1c; 2c) in such a way as to be capable of sliding and supports a piston (1h; 2h). The axial position of this in the cylinder (1a; 2a) determines the volume of an enclosed, gas-filled space (1i; 2i) inside the unit. The piston (1h; 2h) in each spring unit (1; 2) is sealed against the cylinder wall (1a; 2a). The piston (1h; 2h) and/or the end wall (1c; 2c) has a recess which forms an annual chamber (1j; 2j). The piston rod (2b) in the slave spring unit (2) has a smaller diameter than that in the working spring unit (1).

Abstract: A gas spring apparatus includes first and second cylinders each closed at both ends by end walls, first and second pistons each capable of axial displacement being disposed inside a fluid-filled inner space of the cylinders, the first piston dividing the first cylinder into two sub-spaces, the second piston dividing the second cylinder into two cylindrical chamber, first and second piston rods each of, which is connected to the corresponding piston, being mounted in a sliding and sealing fashion in one end wall, and a plurality of valves selectively communicating among two sub-spaces and two cylindrical chambers to decrease pressure inside one of the sub-spaces so as to cause the first piston to be locked for a predetermined period of time, and to cause the first and second pistons to move upwards and back to an initial position of each of the first and second pistons after a predetermined delay. The valves are openable and closable which are controlled by a control device.

Abstract: The invention consists on the one hand of a cylinder (2) closed at its ends by means of end walls (4, 5) and on the other hand of an enclosed space (10). With a piston (3) capable of axial displacement, the cylinder (2) is divided into two sub-spaces (6, 7). The space (10) communicates with the aforementioned first sub-space (6) via a first openable and closable valve (11a). The second sub-space (7) communicates with the aforementioned first sub-space (6) via a second openable and closable valve (13a). A control device (12) actuates the openable and closeable valves (11a, 13a), so that the second valve (13a) is opened when a force (F) acting upon the end of the piston rod (8) has forced the piston (3) in a direction towards the first end wall (4) and into a predetermined position. The second valve (13a) is closed again once pressure equilibrium has been achieved between the sub-spaces (6, 7).