Abstract: A piston-cylinder unit with a center longitudinal axis, a first end, a cylinder filled with a fluid, a piston arranged so as to be displaceable in the cylinder and which divides the cylinder into a first work space remote of the first end and a second work space close to the first end. A piston rod is arranged at the piston and projects through the first work space and is guided out of the cylinder concentric to the center longitudinal axis at a second end opposite the first end so as to be sealed by a guiding and sealing device, and a sensor device for direct or indirect detection of the internal pressure of the piston-cylinder unit.

Abstract: A spring system has a first pulling part with a first fastening element connected by a tension spring to a second pulling part with a second fastening element. The pulling parts are moveable relative to one another so as to increase or relieve stressing on the tension spring. A damping device damps the movement of the pulling parts in relation to one another. A cylinder is fastened on the first pulling part and a piston 3 is axially displacesably arranged therein, subdividing the interior of the cylinder into a first cylinder chamber and a second cylinder chamber. A piston rod connected to the piston is arranged on the second pulling part. The interior of the cylinder is connected to the surroundings via one or more restrictor openings.

Abstract: A ball joint includes a ball head with a radially extending neck, and a socket housing having a ball socket and a fastening shaft which extends radially with respect to the ball socket. The socket has an insertion opening facing transversely of the fastening shaft, the opening having a periphery provided with a pivot notch opposite the fastening shaft, wherein the pivot notch has a width which is smaller than the diameter of the insertion opening and greater than the diameter of the pivot neck. A securing element engages the ball head and loads it into the socket, the securing element being removable away from the insertion opening to release the ball head from the socket. The neck can pivot into the notch while the ball is engaged by the securing element.

Abstract: A spring system has a first pulling part with a first fastening element connected by a tension spring to a second pulling part with a second fastening element. The pulling parts are moveable relative to one another so as to increase or relieve stressing on the tension spring. A damping device damps the movement of the pulling parts in relation to one another. A cylinder is fastened on the first pulling part and a piston 3 is axially displacesably arranged therein, subdividing the interior of the cylinder into a first cylinder chamber and a second cylinder chamber. A piston rod connected to the piston is arranged on the second pulling part. The interior of the cylinder is connected to the surroundings via one or more restrictor openings.

Abstract: A piston/cylinder unit having a selectively inhibited movement includes a cylinder filled with a hydraulic medium and a piston arranged on a piston rod and dividing the cylinder into working spaces. A flow connection system having a flow connection is arranged between the first and second working spaces. The flow connection system includes an on-off valve having a movable valve element which opens the flow connection as a function of a position of the movable valve element. The flow connection system further includes a load-dependent valve arranged in series with the on-off valve for inhibiting complete flow through the flow connection independently from the on-off valve when a load on the piston/cylinder unit is lower than an inhibiting load.

Abstract: A piston/cylinder unit, in particular a gas spring, includes a valve device for the operational motion of a piston rod. The valve device is activatable by an activation device, the activation device being connected near an actuation device and being connected to a load contact device, which influences the function of the valve device. The load contact device connects the actuation device to the valve device for the purpose of changing the adjustability of the valve device when the gas spring is loaded.

Abstract: A piston/cylinder unit, in particular a gas spring, includes a valve device for the operational motion of a piston rod. The valve device is activatable by an activation device, the activation device being connected near an actuation device and being connected to a load contact device, which influences the function of the valve device. The load contact device connects the actuation device to the valve device for the purpose of changing the adjustability of the valve device when the gas spring is loaded.

Abstract: A piston/cylinder unit having a selectively inhibited movement includes a cylinder filled with a hydraulic medium and a piston arranged on a piston rod and dividing the cylinder into working spaces. A flow connection system having a flow connection is arranged between the first and second working spaces. The flow connection system includes an on-off valve having a movable valve element which opens the flow connection as a function of a position of the movable valve element. The flow connection system further includes a load-dependent valve arranged in series with the on-off valve for inhibiting complete flow through the flow connection independently from the on-off valve when a load on the piston/cylinder unit is lower than an inhibiting load.

Abstract: A longitudinally displaceable column includes a longitudinal adjusting unit which is supported on a base plate of a vertical tube. The adjusting unit has a rod that receives an axial bearing, which is interposed between the rod and the base plate so that the rod is rotatable relative to the base plate. The axial bearing is a sliding bearing that has a sliding member.

Abstract: Adjustable-height column, especially for chairs, includes a guide tube and a pneumatic, selectively blockable piston-cylinder unit for height adjustment located in the guide tube. The piston sealingly subdivides the cylinder into two operational chambers. Beginning at a defined retracted setting of the piston-cylinder unit, the blocking function is compulsorily canceled, in that a fluid flow connection between the two operational spaces is established which overrides the blocking function. An additional spring element is placed in series with the piston-cylinder unit to prevent a sudden collapse of the column.

Abstract: A height-adjustable column has a stationary tube that receives a height-changing mechanism, such as a pneumatic spring having a cylinder and a rod that are axially movable with respect to one another. A transmitting mechanism includes a movable member that is operatively associated with the rod and is movable in a direction opposite to the direction of movement of the cylinder upon extension of the pneumatic spring when the pneumatic spring is in a predetermined lift zone.

Abstract: The invention relates to a height-adjustable support device, in particular for the seat (12) of a chair (10), having a base (14) and an upright tube (16) disposed on the base vertically along a center axis (11) thereof, in which a height-adjustment element (18), preferably a gas spring, is arranged so as to be rotatably and/or vertically displaceably guided by a guide surface (34c) disposed concentrically to the center axis and so as to be supported on a support (28) in the lower end section of the upright tube (16). The guide surface (34c) and the support (28) are integrally-formed with the upright tube (16) itself, and the upright tube (16) and the base (14) are made in one-piece of a plastic material.

Abstract: According to an illustrative example of the invention, a chair column comprises a lockable gas spring for height adjustment of the chair column. The gas spring is inserted into a stand tube of the chair column. The piston rod extends downwards and is rotatably fastened to a bottom part of the stand tube. The cylinder of the gas spring extends upwards out of the upper end of the stand tube. At the upper end of the cylinder there is provided in axial alignment with the axis of the cylinder a valve pin. A pushing member acts onto the valve pin. The pushing member is connected with a Bowden cable. One end of the Bowden cable core is fastened to a guide sleeve of the pushing member. The tube member of the Bowden cable acts onto the pushing member. The other end of the Bowden cable is connected to a releasing lever by which the valve can be opened. When the valve is opened, the working chambers located on both sides of a piston are interconnected so that height adjustment of the gas spring is possible.

Abstract: According to an illustrative example of the invention, a chair column comprises a base tube with a support plate. A gas spring is accommodated within the base tube. The piston rod of the gas spring is supported on the base tube by a ball bearing. The cylinder of the gas spring is guided at the upper end of the base tube by a guiding sleeve. The guiding sleeve is telescopical with respect to the base tube in response to outward and inward movement of the cylinder with respect to the base tube such that a full satisfactory guiding function is maintained between the cylinder and the base tube, even when the cylinder is in its uppermost position.

Abstract: A chair column comprises a stand tube. A support bush is inserted into the upper end portion of the stand tube. A gas spring cylinder extends axially through the receiver bush. The piston rod is directed downward and is connected with a bottom of the stand tube. The gas spring cylinder is guided through two axially spaced bearing bushes. The bearing bushes are radially supported by the receiver bush through a radially prestressed transmission ring or a plurality of circumferentially distributed buffers. The radial prestress is transmitted to the contact face between the bearing bushes and the gas spring cylinder.

Abstract: For a steplessly adjustable vertical movement device for chairs, tables or the like articles, which comprises a blockable gas spring which is arranged in a telescopic unit consisting of a telescopic tube and a guide tube and is connected by means of self-locking taper connections on the one hand with the chair seat or a similar article of adjustable height and on the other hand with a foot part, a simple replacement of the gas spring is to be provided, while security against unintended unscrewing of the gas spring is guaranteed. The gas spring should here be as simple as possible in construction, permit easy assembly and dismantlement and be arranged as freely as possible from bending stresses in the telescopic unit.

Abstract: A positioning device is used for the positioning of a chair seat as to its inclination, or for positioning a back-rest member of a chair. The positioning device is constructed such as usual hydropneumatic springs which can be locked by closing a passage connected to working chambers on both sides of a piston. The working chambers are filled with an operating liquid. In order to adapt the biasing force of such a positioning device, one of the working chambers is conneced with a force-measuring device, which force measuring device is provided within the force transmission path of the respective chair column. The force measuring device comprises a measuring space filled with operating liquid, and this operating liquid is in liquid connection with one of the working chambers.

Abstract: A continuously adjustable levelling column for chairs comprises a guide tube having a lower end and an upper end. A telescopic tube is guided within the guide tube and has a tapered upper end portion extending beyond the upper end of the guide tube. A gas spring is accommodated within the telescopic tube. This gas spring is axially fixed within the telescopic tube. The upper end of a container of the gas spring abuts through a distance piece a support face at the upper end of the tapered portion of the telescopic tube. A piston rod passing through the lower end of the gas spring is axially fixed with respect to the lower end of the guide tube. A locking control pin extends through the upper end of the gas spring and is engageable through a transmission pin by a control handle.