Abstract: A piston-cylinder unit, comprising a cylinder which is subdivided by a piston on a piston rod into two working chambers. Between the two working chambers, there is a fluid connection which can be blocked by means of a valve arrangement having at least two individual closing valves arranged in series, each with a valve inflow side and a valve outflow side. The valves open sequentially. In the flow path between the individual valves, there is a throttle arrangement which produces a pressure reduction between the valve outflow side of the first closing valve towards the valve inflow side of the following closing valve. As the opening of the first closing valve increases, the effect of the throttle arrangement decreases; to the same extent, the pressurization increases on the valve inflow side of the following closing valve. The valve arrangement features two flow-through directions and is made so that each can be blocked.

Abstract: A piston/cylinder assembly includes a cylinder and a piston received in the cylinder for axial movement and dividing the cylinder into two working chambers. A first connecting member is affixed to the cylinder and is adapted to connect the cylinder to one of two elements that are movable relative to each other. At least one second connecting member is operatively coupled to the piston, extends through an opening in the cylinder, and is adapted to connect the piston to the other of the two elements. The opening has a length axially of the cylinder that is not less than the length of the stroke of the piston.

Abstract: A detent device for locking first and second elements that are movable relative to one another includes a first subassembly connected to a first element and a second subassembly connected to the second element. A first locking mechanism of the detent device can be controlled at will by use of an actuating mechanism. The first locking mechanism is subordinated to a second locking mechanism that acts independently of the first locking mechanism as soon as a threshold value of the relative speed of the two subassemblies of the detent device is exceeded. The second locking mechanism includes a first locking element and a second locking element, the first locking element being functionally associated with the first subassembly and the second locking element being functionally associated with the second subassembly. The first and the second locking elements form a clutch. In addition, the locking mechanism can also have two states of locking actuation.

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 pressurized gas spring, which exerts an expulsion force on the piston rod entailing a maximum extension velocity of the piston rod, includes braking means effective at a velocity of motion due to external forces above the maximum extension velocity for limiting the velocity of motion to a desired measure.

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: A piston-cylinder unit includes a piston which divides the cylinder into two working chambers, a sealing valve seals a flow path between the two working chambers in the stationary operating condition of the unit. The sealing valve has a valve element consisting of an axially movable radially sealing sealing ring in conjunction with a valve ring, which at its back is supported by a spring-biased member. The slide member and the valve ring form therebetween a flow-off chamber having a flow-off opening that is sized so that unrestricted fluid flow is permitted so as to prevent the formation of a ram pressure in the flow-off chamber. The sealing ring is movable between three axial positions relative to the valve ring. At a center position, the sealing ring seals the flow path against fluid flow. At the two other positions, the sealing ring permits fluid flow in opposite directions.

Abstract: A piston-cylinder unit includes a cylinder having an axis and an inner surface and a piston assembly attached to a piston rod and received in the cylinder for axial movement. The piston assembly includes a piston body, which has a plurality of radially resiliently deformable wall portions at its perimeter, the wall portions being spaced apart circumferentially from each other. Each wall portion has opposite ends that are joined integrally with the piston body and is defined by an opening in the body. Each wall portion engages the inner surface of the cylinder and deforms resiliently radially with respect to the axis of the cylinder to compensate for tolerance variations in the inner surface of the cylinder. The piston assembly may include a piston ring, which is received on the piston body with centering surfaces to restrict its radial movement and which functions to block and unblock a fluid bypass between sections of the cylinder on opposite sides of the piston assembly.

Abstract: A vertically adjustable column, in particular for chairs or tables, includes a pedestal tube having a coaxially arranged lengthwise adjusting element, e.g., a gas spring, and a rotational fixation profile engaging a counterpart profile extending parallel to the longitudinal centerline of the pedestal tube. The rotational fixation profile and the counterpart profile are operatively arranged between the pedestal tube and the lengthwise adjusting element, and one of the profile parts is arranged in series with the lengthwise adjusting element.

Abstract: Vehicle including a body component and an additional body part, particularly a hatch door, which is movably mounted on the body component. The hatch door can be mounted on a power-assisted pivoting axis by means of a pneumatic spring or strut hinged by connection elements to form a pneumatic spring assembly. The vehicle has a component, particularly a trunk compartment cover, which moves simultaneously with an hatch door by means of a connection. The connection is mounted between the component and the pneumatic spring assembly.

Abstract: Fluid strut which consists of a cylinder, the interior of which contains a charge under pressure, and a piston rod connected to a piston located in this interior.

Abstract: A pneumatic strut for use as an opening power assist mechanism for a motor vehicle tailgate has a piston rod extending from a piston contained within a cylinder. The piston separates the cylinder into two work chambers, each containing a gas charge under pressure. A bypass opening is active to connect the work chambers during the initial opening displacement of the tailgate to automatically open the tailgate through a first opening angle range. A second valve can be externally actuated to connect the two work chambers to further selectively open the tailgate into a second opening angle range. To close the tailgate, a third, directionally dependent valve can automatically connect the two work chambers during the closing displacement of the tailgate.

Abstract: A longitudinally adjustable column for chairs, tables or the like, comprising a vertical tube and a longitudinal adjusting element arranged inside the tube. The longitudinal adjusting element has a cylinder with an axially movable piston rod, and is mounted on a base plate which is held in place inside the tube. The base plate is held in place on one side by an inwardly-bent deformation of the vertical tube, and on the other side by at least one supporting surface on the inner wall of the vertical tube. The deformation is formed by bending a face at one end of the tube in the direction of the inner wall of the tube, so that the outer wall of the tube rests against one side of the base plate.

Abstract: Height adjustable object carrier column for use as a chair column of a revolving chair. The head area of the chair is moved back to a rest height and angular orientation with respect to the foot area of the chair upon relief of the chair load. The head area can be adjusted with respect to the foot area, by height adjustment apparatus, to different rest heights. Height adjustment is provided in the form of a hydraulic or a hydropneumatic or a spring-hydraulic or a pneumatic actuator with a cylinder assembly and a piston rod assembly which are coaxial to a telescope axis. The height adjustment apparatus includes internal biasing structure and first arbitrarily adjustable and second automatic blocking devices, whereby following a reduction of the load on the object carrier column, the second blocking device is released, and the height adjustment apparatus is moved toward a specified limit position, and the stop moves the object carrier column into the specified rest angular orientation.

Abstract: A positioning element to position two objects which are movable in relation to one another includes a cylinder in which there is an axially movable piston rod with a piston. The piston sealingly divides the cylinder into two working chambers by a piston ring, each of the working chambers containing blocking medium. The sealing by the piston ring can be bypassed during an insertion stroke of the piston rod. The piston includes a piston base body and a valve element, the valve element being movable along the base body to open and close a flow connection between the working chambers. An external opening force can displace the valve element to open the flow connection and permit an automatic extension stroke of the piston rod. The valve element remains open during the extension stroke on account of the flow of blocking medium through the flow connection. The valve element can be displaced to close the flow connection in response to stopping the extension stroke of the piston rod to position the two objects.

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: Hinge eye for a piston-cylinder unit, or shock absorber, in particular for air springs, comprising a bracket with an opening, a bearing surface for a connection shank which is connected to a base body, and at least one retaining tab. The retaining tab is actively connected to the piston-cylinder unit and forms a locking connection with a groove of the connection shank. The retaining tab(s) and the part of the hinge eye which forms the opening with the bearing surface are realized in one piece.

Abstract: A locking device for selectively securing two movable objects in desired positions relative to each other includes a cylinder and a piston movable within the cylinder and defining first and second working chambers of variable volumes. A fluid exchange connection provided on the piston includes a flow chamber having openings that communicate with the working chambers. A valve body slidably received on the piston in sealed relation is biased by a spring into a position closing the opening from the flow chamber to first working chamber. When the fluid pressure in the second working chamber exceeds a predetermined amount and acts on the valve body, the valve body is moved against the spring bias and opens to allow fluid to flow through the fluid exchange connection. In the open position, a larger area of the valve body is exposed to the pressure in the second chamber.

Abstract: A hydraulic strut for a motor vehicle for providing a movement guiding and dampening function can generally have a cylinder, with a piston disposed in the cylinder to divide the cylinder into at least first and second chamber portions, with a piston rod extending from the piston out of the cylinder. The cylinder can be sealed at both ends, and can preferably be filled with hydraulic fluid. The piston can preferably define a flow connection between the two fluid chambers, and this flow connection can typically have some sort of valve arrangement therein for controlling flow of fluid between the first and second chamber portions.

Abstract: Pneumatic, hydraulic or hydropneumatic adjustment device with a tubular container under pressure, which is divided into two work chambers by a piston fastened to a piston rod, whereby there is a locking device which can be tripped by a tripping tappet which runs lengthwise through the piston rod and extends outward. The tripping tappet is actuated by way of a motor, whereby there is an axially movable tripping element between the drive shaft of the motor and the tripping tappet.