| 摘要 |
A gas-operated piston cylinder assembly arranged between upper and lower die members of a press. The lower end of the cylinder communicates with a source of high pressure gas and also communicates through a passageway with the upper rod end of the cylinder which is sealed from the surrounding atmosphere. The piston rod has a cross sectional area only slightly smaller than the piston. The passageway between the lower and the upper ends of the cylinder contains a lubricant impregnated member and a by-pass controlled by a check valve which allows gas flowing from the rod end of the cylinder to the lower end thereof to bypass the lubricant impregnated member. |
