Cylinder

A cylinder having an output member accommodated in a cylinder hole provided in a housing moveable up and down in the cylinder hole by a pressurized fluid, comprising:

• a first valve chamber provided between a lower wall of the housing and the output member;
• a sheath chamber being a hollowed out portion of the output member so as to be open toward the first valve chamber;
• a valve rod protruding from the lower wall and configured to be inserted into the sheath chamber,
• said valve rod comprising:
• a valve rod passage provided in a length direction of the valve rod;
• a seal section provided on an outer peripheral wall side of the valve rod or an inner peripheral wall side of the sheath chamber;
• and
• a plurality of bypass passages connecting the first valve chamber and the valve rod passage, one bypass passage being spaced from at least one other bypass passage,
• wherein a predetermined pressure loss by the plurality of bypass passages occurs when the valve rod and the sheath chamber move relative to each other.

A cylinder having an output member accommodated in a cylinder hole provided in a housing and moveable up and down in the cylinder hole by a pressurized fluid, comprising:

• a valve rod protruding from a lower wall of the housing;
• a second valve chamber being a hollowed out portion of the output member so as to receive the valve rod,
• said valve rod comprising:
• a first valve rod passage and a second valve rod passage each being open toward the second valve chamber;
• and
• a pair of seal sections being operably associated with the valve rod and the second valve chamber;
• wherein a compressed air flow passage formed between the first valve rod passage and the second valve rod passage is configured so as to have a closed region sealed by the pair of seal sections when the valve rod is in a first position and to have an open region free of sealing by the pair of sealing sections when the valve rod is in a second position,
• wherein compressed air is supplied from one end of the compressed air flow passage and another end of the compressed air flow passage is open to an outside air.