| 摘要 |
PROBLEM TO BE SOLVED: To selectively drive to ascend and descend matrix-like arranged, air cylinder-driven pins with a reasonable air supply and discharge system. SOLUTION: There are provided with a first air passage 10 connected to air cylinders 2 for driving pins 1 in each row, a second air passage 11 connected to air cylinders 2 for driving pins 1 in each column, and a third air passage 12 connected to all the cylinders 2. Switching valves 13 to 15 are provided for the passages 10 to 12, respectively. The passages 10 and 12 are allowed to communicate with an upper pressure chamber 6 and a lower pressure chamber 7, respectively. Each cylinder 2 is arranged in such a manner that the chamber 7 is not allowed to communicate with the passage 12 when a piston rod 4 is in the lowest point. Further, the rod 4 has a constriction at an upper part of a piston 5, and further a communicating passage 8 allowing the chamber 7 to communicate with the circumference of the constriction is formed inside the rod 4. It is also arranged that the passage 11 is opened onto each cylinder 3 at the position of the constriction when the rod 4 is at the lowest point. |
