| 摘要 |
PURPOSE:To close two pairs of holding arms by one driving source by installing an arm opening/closing member at the top edge of a pulling rod and installing said arm opening/closing member onto a replacement head and forming a fitting part onto one among the arm opening/closing member and each holding arm and forming a guide groove onto the other and forming the guide plane of said guide groove into an inclined plane. CONSTITUTION:An arm opening/closing member 25 is installed onto a replacement hard 11. The relative shift between the guiding inclined planes of the guide grooves 28L and 28R and a fitted part 20 is generated by the shift in one of two axis line CL directions of the arm opening/closing member 25, and the tools T1 and T2 are held by the closing of two pairs of holding arms 23L and 23R. At this time, if one pairs of holding arms 23L and 23R firmly hold the tool T1 and the other pairs of holding arms 23L and 23R form a gap from the tool T2, the arm opening/closing member 25 is shifted towards the other pairs of holding arms 23R and 23R by the force acting onto the above-described guiding inclined plane, and also the tool T2 is firmly held. Further, the force in two axis line CL directions of the arm opening/ closing member 25 in holding is increased and transmitted to the holding arms 23L and 23R by the wedge action of the guiding inclined plane. |
