| 摘要 |
PURPOSE:To make the titled device small-sized without using a large device, by transmitting a motion of an upper holder as a rotary motion to a punch holder, and varying the extent of projection of a punch. CONSTITUTION:Balls 19a, 19b incorporated in hook holes 18a, 18b of a punch holder 15 advance, drawing a spiral locus along a guide groove 28a between saw teeth formed on both guides 20, 27. Accordingly, the holder 15 is turnes, a projecting part provided on the holder 15 is inserted into a recess part formed by a through-hole 24, and a stage part 23 press-contacts with a projecting part 16. Accordingly, a punch 13 projects from a casing 29 and performs working to a work 12. When a ram is raised, the balls 19a, 19b advance by one frame portion along the guide groove 28a, and the holder 15 is turned by that portion. When the ram is lowered, the balls 19a, 19b advance by one frame portion along the guide groove 28a, the holder 15 is turned, the projecting part 16 is fitted into a recess part of the guide 20, and when the ram has reached the bottom dead center, the punch 13 is fitted into the casing 29, and since there is no extent of projection for working the work 12, no working is performed. |
