Abstract: A screwdriver includes a handle having a longitudinal axis. At the one end of the handle, the screwdriver includes a bit holder extending in the direction of the longitudinal axis or a screwdriver blade extending in the direction of the longitudinal axis. The screwdriver is further includes a drive mechanism in the handle. The drive mechanism causes a bit holder in the handle or the screwdriver blade opposite the handle to rotate. The drive mechanism includes a motor and a freewheel through which the motor can be coupled to the bit holder or the screwdriver blade. The freewheel is designed to relieve the torque when manual torque is introduced into the bit holder or the screwdriver blade through the handle. The drive mechanism further includes a torque limiter for limiting the drive torque of the motor on the bit holder or the blade.

Abstract: A screwdriver includes a handle having a longitudinal axis. At the one end of the handle, the screwdriver includes a bit holder extending in the direction of the longitudinal axis or a screwdriver blade extending in the direction of the longitudinal axis. The screwdriver is further includes a drive mechanism in the handle. The drive mechanism causes a bit holder in the handle or the screwdriver blade opposite the handle to rotate. The drive mechanism includes a motor and a freewheel through which the motor can be coupled to the bit holder or the screwdriver blade. The freewheel is designed to relieve the torque when manual torque is introduced into the bit holder or the screwdriver blade through the handle. The drive mechanism further includes a torque limiter for limiting the drive torque of the motor on the bit holder or the blade.

Abstract: An adjustable length gas spring comprises a casing and a piston which is disposed for displacement in the casing and joined to a piston rod. An externally operable adjusting valve is formed in the piston. Further, the piston is provided with a traction valve, which, upon application of tractive force from outside, cancels any blockage of the piston.

Abstract: An adjustable-height chair column comprises an upright tube and a gas spring that is disposed coaxially in the upright tube. The gas spring comprises a valve for actuation of the gas spring. This valve is embodied for opening upon relief of the casing of the gas spring in relation to the upright tube.

Abstract: An adjustable-length compression spring comprises a casing filled with pressure fluid. A piston rod is sealingly extended through a guide and seal unit which closes the casing, a piston, which is sealingly guided therein, being joined to the piston rod. The piston divides the casing into two sectional casing chambers, which are filled with pressure fluid. For connection to each other of the sectional casing chambers, provision is made for a valve operated by a valve pin. The casing includes a locking mechanism which comprises a first and a second locking element, the first of which being in pushing connection with a first operating element and the second with the valve pin.

Abstract: An adjustable length gas spring comprises a casing and a piston which is disposed for displacement in the casing and joined to a piston rod. An externally operable adjusting valve is formed in the piston. Further, the piston is provided with a traction valve, which, upon application of tractive force from outside, cancels any blockage of the piston.

Abstract: A compression spring comprises a casing in which a piston is arranged for displacement, the piston being mounted on a piston rod. In the casing provision is made for two sectional casing chambers which are filled with pressure fluid, at least one of which being defined by the piston. A first operating valve, in an open position, connects the sectional casing chambers to each other and, in a shut-off position, blocks the compression spring. An additional throttle element ensures that an actuation and over-flow assembly between the sectional casing chambers is completely open only when the throttle element, with the valve pin tripped, is simultaneously moved by corresponding actuation into a position of release. Without any such actuation of the throttle element, there will be only throttled flow between the sectional casing chambers. Any inadvertent extension of the piston rod is thus precluded. This is an especially convenient and intuitive way of backrest adjustment in a seat.

Abstract: The invention comprises an adjustable length gas spring, having a casing which has a central longitudinal axis and is filled with a pressure fluid; a guide and seal unit which closes the casing at a first end thereof; a piston rod which has an outer end and is extended through, and sealed towards, the guide and seal unit out of the first end; a piston which is guided in, and sealed towards, the casing and connected with the piston rod; a first sectional casing chamber which is formed between the piston and the guide and seal unit; a second sectional casing chamber which is defined by the piston and faces away from the first sectional casing chamber; a valve which is disposed in the vicinity of the piston for interconnection of the sectional casing chambers, the valve having a valve pin, which is displaceable along the central longitudinal axis, for actuation of the valve from outside the casing; and at least one spring element, which is disposed between the piston and the first end of the casing, and which en

Abstract: An adjustable-height chair column comprises an upright tube and a gas spring that is disposed coaxially in the upright tube. The gas spring comprises a valve for actuation of the gas spring. This valve is embodied for opening upon relief of the casing of the gas spring in relation to the upright tube.

Abstract: An adjustable-length compression spring comprises a casing filled with pressure fluid. A piston rod is sealingly extended through a guide and seal unit which closes the casing, a piston, which is sealingly guided therein, being joined to the piston rod. The piston divides the casing into two sectional casing chambers, which are filled with pressure fluid. For connection to each other of the sectional casing chambers, provision is made for a valve operated by a valve pin. The casing includes a locking mechanism which comprises a first and a second locking element, the first of which being in pushing connection with a first operating element and the second with the valve pin.

Abstract: A compression spring comprises a casing in which a piston is arranged for displacement, the piston being mounted on a piston rod. In the casing provision is made for two sectional casing chambers which are filled with pressure fluid, at least one of which being defined by the piston. A first operating valve, in an open position, connects the sectional casing chambers to each other and, in a shut-off position, blocks the compression spring. An additional throttle element ensures that an actuation and over-flow assembly between the sectional casing chambers is completely open only when the throttle element, with the valve pin tripped, is simultaneously moved by corresponding actuation into a position of release. Without any such actuation of the throttle element, there will be only throttled flow between the sectional casing chambers. Any inadvertent extension of the piston rod is thus precluded. This is an especially convenient and intuitive way of backrest adjustment in a seat.

Abstract: A governor for air compressors of vehicles, that serves to control additional devices, especially energy-saving devices. From an inlet connection supplied from the compressed air supply, a pilot valve designed as a round slide valve with a small cross section is controlled. The pilot valve monitors the supply of compressed air to a switching piston for a double valve with a large cross section. The double valve is supplied with compressed air from the inlet connection and causes an outlet connection connected with the additional device to be charged with air or cut off from the air. The switching piston is connected with a valve tube of the round slide valve in such fashion that this valve, during switching processes, is moved in a direction opposite to that of regulating piston of the pilot valve, so that a precise switching of the governor that reflects the pressure differential is achieved at the upper and lower pressure limits.