Abstract: A support column with a vertical tube has a coaxially installed gas spring including a cylinder divided by a piston into first and second working chambers. A piston rod passes through the second working chamber in a sealed manner to the outside, where it is attached to a bottom support piece of the vertical tube. The cylinder projects out of the vertical tube and is guided with freedom to slide back and forth in a guide sleeve installed in the end of the vertical tube opposite the bottom support piece. A connection between the first and second working chambers can be blocked by a manually actuatable valve. A second valve between the chambers, which is closed when the gas spring is under load, can be switched to the open position after the load on the gas spring has been absent for a certain period of time.

Abstract: A vertically adjustable item of furniture with a vertical pipe, a supporting base arranged at a first end of the vertical pipe, a guide bush fastened to a second end of the vertical pipe opposite to the supporting base, a cylinder which is arranged coaxially in the vertical pipe a piston which divides the cylinder into a first work chamber and a second work chamber, a piston rod fastened by its first end to the piston extends through the second work chamber and a connection between the first work chamber and the second work chamber which can be blocked by a valve actuatable by an actuating device. The valve is controllable electromagnetically. The furniture item comprises a sensor or switch which generates a signal causing the valve to close when the piston reaches a position in the cylinder near the valve.

Abstract: A vertically adjustable item of furniture with a vertical pipe, a supporting base arranged at a first end of the vertical pipe, a guide bush fastened to a second end of the vertical pipe opposite to the supporting base, a cylinder which is arranged coaxially in the vertical pipe a piston which divides the cylinder into a first work chamber and a second work chamber, a piston rod fastened by its first end to the piston extends through the second work chamber and a connection between the first work chamber and the second work chamber which can be blocked by a valve actuatable by an actuating device. The valve is controllable electromagnetically. The furniture item comprises a sensor or switch which generates a signal causing the valve to close when the piston reaches a position in the cylinder near the valve.

Abstract: A support column with a vertical tube has a coaxially installed gas spring including a cylinder divided by a piston into first and second working chambers. A piston rod passes through the second working chamber in a sealed manner to the outside, where it is attached to a bottom support piece of the vertical tube. The cylinder projects out of the vertical tube and is guided with freedom to slide back and forth in a guide sleeve installed in the end of the vertical tube opposite the bottom support piece. A connection between the first and second working chambers can be blocked by a manually actuatable valve. A second valve between the chambers, which is closed when the gas spring is under load, can be switched to the open position after the load on the gas spring has been absent for a certain period of time.