Abstract: According to an illustrative example of the invention, a gas spring is provided with an emergency exit permitting escape of pressurized gas in the event the gas pressure exceeds a predetermined level or in the event of a dangerously high temperature. The emergency exit includes one or more fluid passages connecting the interior of the gas spring to atmosphere and a cooperating seal member for maintaining the fluid passage or passages closed under normal operating conditions. Upon the occurrence of unduly high pressures or temperatures, a destructible or deformable support for the seal or a fluid passage-bearing member permits relative movement of the seal and the cooperating fluid passage so as to open the fluid passage. As an intermediate step of pressure relief, the structure for mounting the gas spring in its environment of use, e.g. a motor vehicle, may be designed to fail under emergency conditions, e.g., fire, thereby permitting a full extension of the piston rod.

Abstract: According to an illustrative example of the invention, a gas spring is provided with an emergency exit permitting escape of pressurized gas in case of said pressurized gas exceeding a predetermined pressure. The emergency exit is provided by a radial bore through the cylinder. This radial bore is covered under normal conditions by a piston rod seal. This piston rod seal is axially displaceable by said pressurized gas at said predetermined pressure such that the radial bore is opened for escape of pressurized gas.

Abstract: A telescopic spring unit with two telescopic parts capable of being shifted, one in relation to the other, along a telescopic axis, which telescopic spring unit, when in its lengthened state, is lockable by means of a locking unit that is arranged on one of the telescopic parts and is pivotable around a tilting joint into a stop position. First and second pivoting elements are provided on the two telescopic parts, respectively, for pivotally connecting the spring unit to an articulated structural assembly. The pivoting elements of the telescopic part connected to the locking unit is attached to the locking unit, and the tilting joint and the pivoting elements are coordinated with one another in a manner such that, in the lengthened state of the telescopic spring unit, a force that acts on the telescopic spring unit through the two pivoting points in the compressive direction exerts a tilting moment on the locking unit which biases the locking unit around the tilting joint towards the stop position.

Abstract: A pneumatic spring is equipped with a shell tube (12) which is telescopically guided on a pneumatic-spring cylinder (9) and which can snap into different positions. For bolting between the shell tube (12) and the pneumatic-spring cylinder (9), a bolt body (16) is attached to the cylinder bottom (17). In the bolt body (16), a bolt (18) is spring-loaded by a resilient force directed radially outward. In order to bolt the pneumatic-spring cylinder (9) relative to the shell tube (12), the bolt (18) engages in various breaches (19a and 19). Finger pressure required to release the bolting depends on which one of the two relative-shift directions between the pneumatic-spring cylinder (9) and the shell tube (12) is intended. (FIG.

Abstract: In a gas spring the piston rod is guided through one end of a container. Adjacent to this one end two sealings are provided in axial direction one behind the other, namely an axially outer sealing and an axially inner sealing. A liquid chamber is defined between the axially outer sealing and the axially inner sealing. The axially inner sealing comprises a sealing ring of elastomeric material. This sealing ring comprises a radially outer root portion and a radially inner lip portion. The root portion engages an internal circumferential surface of the container tube. The lip portion engages an external circumferential surface of the piston rod. The axial dimension of the root portion is substantially larger than the axial dimension of the lip portion. The sealing ring may be deflected by pressure differences on both sides of the sealing ring such that a fluid exchange is possible between both axial sides of the sealing ring when the pressure difference exceeds a predetermined value.

Abstract: A positioning device is e.g. used for positioning the door of a motor vehicle in an opened position. The positioning device comprises e.g. a cylinder and a piston rod which extends inward and outwards of the cylinder through one end thereof. A flank face is provided at the inner wall surface of the cylinder. The piston rod carries a piston. The piston is provided with a counter-arresting ring which engages the flank face in a predetermined position. When the piston passes across the arresting flank of the cylinder, the counter-arresting ring is moved radially inwards with respect to the axis of the piston rod against elastic resistence. So, an increased resistance occurs against the axial movement of the piston rod with respect to the cylinder. This increased resistance against axial movement positions the door with respect to the body frame of a motor vehicle in a predetermined opened position and avoids that the door is closed unintentionally.