| 摘要 |
A pistol grip drill ( 1 ) has two control triggers ( 3 and 9 ) on its hand grip ( 4 ). One trigger ( 3 ) controls power to a motor in a casing ( 2 ) of the drill and the other trigger ( 9 ) initiates a sequence which interchanges the positions of two chucks ( 20, 21 ). The chucks ( 20, 21 ) are mounted on a forward extension ( 8 ) of the casing ( 2 ). The extension ( 8 ) has two degrees of freedom. It is firstly capable of rotating through ninety degrees about the axis of a pivot ( 14 ) to bring the unused chuck to the driving position in front of the casing ( 2 ). The second degree of freedom allows the extension to be then rotated about the driving axis of a drill drive shaft ( 5 ) so that the displaced chuck is moved from an upwardly-pointing position to a downwardly position directly in front of the pistol grip. The interchanging of the chucks ( 20, 21 ) can be controlled by the hand of the user holding the hand grip ( 4 ). |
