| 摘要 |
PURPOSE:To locate a head body at a different angle by fixing an engaging stoppage member in which two strings of engaging stoppage projections are formed, on a peripheral face of the head body, and making a location member opposed to the engaging stoppage member movable forward and backward, by having any one of the engaging stoppage projections engaged for stop through the rotation of the head body. CONSTITUTION:An engaging stoppage member 30 being fixed on a peripheral face of a head body 13, two strings of engaging stoppage projections 32a, 32b are formed thereon. Opposed to the engaging stoppage member 30, a location member 39 in which an engaging stoppage groove 40 is formed is arranged in a way it can move forward and backward. The head body 18 is revolved through the pressure of a first and a second hydraulic cylinders 42a, 42b, for either of the engaging stoppage projections 32a, 32b to be opposed to the groove 40 of the location member 39. The, the location member 39 being advanced, either the projection 32a or the projection 32b is put into the groove 40 and is located for fixation. In this way, it is possible to fix each main shaft 26a..., 26b... of the head body 18 at a position diversed at the predetermined space, the process of plural holes approached each other can thus be performed effectively. |
