Adjustable-length gas spring

An adjustable-length gas spring, comprising

• a casing (1) which has a central longitudinal axis (2) and is filled with a liquid pressure fluid;
• a guide and seal unit (10) which closes the casing (1) at a first end;
• a piston rod (8) for sealed guidance through the guide and seal unit (10) out of the first end of the casing (1);
• a piston (9) for sealed guidance in the casing (1), the piston (9) being joined to the piston rod (8);
• a first divisional interior chamber (7b) which is formed between the piston (9) and the guide and seal unit (10);
• a second divisional interior chamber (7a) which is defined by the piston (9) and turned away from the first divisional interior chamber (7b);
• an adjusting valve (37) which is disposed in the piston (9) and interconnects the first and second divisional interior chamber (7a, 7b), having
• a valve control pin (20) which is displaceable in a direction of the central longitudinal axis (2),
• a valve tray (21) which is mounted on the valve control pin (20),
• a first sealing seat (24), and
• a first sealing contact surface which cooperates with the first sealing seat (24),
• the first sealing seat (24) and the first sealing contact surface being liftable off each other by means of the valve control pin (20);
• a traction valve (38), which is disposed on the piston (9), for interconnection of the first and second divisional interior chamber (7a, 7b) when tractive force acts between the piston rod (8) and the casing (1), the traction valve (38) having
• a second sealing seat (32), and
• a second sealing contact surface that cooperates with the second sealing seat (32),
• the second sealing seat (32) and the second sealing contact surface, upon increase of pressure in the first divisional interior chamber (7b), being liftable off each other while the traction valve (38) opens;
• and
• the adjusting valve (37) and the traction valve (38) having a joint sliding bush (26) which is guided for displacement on the valve control pin (20) in the direction of the central longitudinal axis (2) and bears either the first or second sealing contact surface or the first or second sealing seat (24, 32),
• wherein the adjusting valve (37), when shut off, has a surface F37 which is in connection with the first divisional interior chamber (7b);
• wherein the traction valve (38), when shut off, has a surface F38 which is in connection with the first divisional interior chamber (7b);
• and
• wherein F38>F37 applies.

An adjustable-length gas spring, comprising

• a casing (1) which has a central longitudinal axis (2) and is filled with a liquid pressure fluid;
• a guide and seal unit (10) which closes the casing (1) at a first end;
• a piston rod (8) for sealed guidance through the guide and seal unit (10) out of the first end of the casing (1);
• a piston (9) for sealed guidance in the casing (1), the piston (9) being joined to the piston rod (8);
• a first divisional interior chamber (7b) which is formed between the piston (9) and the guide and seal unit (10);
• a second divisional interior chamber (7a) which is defined by the piston (9) and turned away from the first divisional interior chamber (7b);
• an adjusting valve (37) which is disposed in the piston (9) and interconnects the first and second divisional interior chamber (7a, 7b), having
• a valve control pin (20) which is displaceable in a direction of the central longitudinal axis (2),
• a valve tray (21) which is mounted on the valve control pin (20),
• a first sealing seat (24), and
• a first sealing contact surface which cooperates with the first sealing seat (24),
• the first sealing seat (24) and the first sealing contact surface being liftable off each other by means of the valve control pin (20);
• a traction valve (38), which is disposed on the piston (9), for interconnection of the first and second divisional interior chamber (7a, 7b) when tractive force acts between the piston rod (8) and the casing (1), the traction valve (38) having
• a second sealing seat (32), and
• a second sealing contact surface that cooperates with the second sealing seat (32),
• the second sealing seat (32) and the second sealing contact surface, upon increase of pressure in the first divisional interior chamber (7b), being liftable off each other while the traction valve (38) opens;
• and
• the adjusting valve (37) and the traction valve (38) having a joint sliding bush (26) which is guided for displacement on the valve control pin (20) in the direction of the central longitudinal axis (2) and bears either the first or second sealing contact surface or the first or second sealing seat (24, 32), wherein the sliding bush (26) supports a valve disk (29) on which the first sealing contact surface and the second sealing contact surface are formed.

An adjustable-length gas spring, comprising

• a casing (1) which has a central longitudinal axis (2) and is filled with a liquid pressure fluid;
• a guide and seal unit (10) which closes the casing (1) at a first end;
• a piston rod (8) for sealed guidance through the guide and seal unit (10) out of the first end of the casing (1);
• a piston (9) for sealed guidance in the casing (1), the piston (9) being joined to the piston rod (8);
• a first divisional interior chamber (7b) which is formed between the piston (9) and the guide and seal unit (10);
• a second divisional interior chamber (7a) which is defined by the piston (9) and turned away from the first divisional interior chamber (7b);
• an adjusting valve (37) which is disposed in the piston (9) and interconnects the first and second divisional interior chamber (7a, 7b), having
• a valve control pin (20) which is displaceable in a direction of the central longitudinal axis (2),
• a valve tray (21) which is mounted on the valve control pin (20),
• a first sealing seat (24), and
• a first sealing contact surface which cooperates with the first sealing seat (24),
• the first sealing seat (24) and the first sealing contact surface being liftable off each other by means of the valve control pin (20);
• a traction valve (38), which is disposed on the piston (9), for interconnection of the first and second divisional interior chamber (7a, 7b) when tractive force acts between the piston rod (8) and the casing (1), the traction valve (38) having
• a second sealing seat (32), and
• a second sealing contact surface that cooperates with the second sealing seat (32),
• the second sealing seat (32) and the second sealing contact surface, upon increase of pressure in the first divisional interior chamber (7b), being liftable off each other while the traction valve (38) opens;
• and
• the adjusting valve (37) and the traction valve (38) having a joint sliding bush (26) which is guided for displacement on the valve control pin (20) in the direction of the central longitudinal axis (2) and bears either the first or second sealing contact surface or the first or second sealing seat (24, 32),
• wherein the first sealing seat (24) has the shape of a circular ring and a diameter D24;
• and wherein the second sealing seat (32) has the shape of a circular ring and a diameter D32;
• and wherein D32>D24 applies.