| 摘要 |
<p>A pistol grip casing (2) contains the two chucks (6 & 7) which are selectively positionable at their positions of use in front of the casing. A drive motor (31) is selectively connectable to the chuck at its position of use by the engagement of pinions (34 & 35) with whichever of the pinions (10 & 11) is mounted on the respective drive shafts (8 & 9) of the chuck at the position of use. Selection of the chuck (6 & 7) to be at the position of use is achieved by depressing a button (32) at the back of the casing (2) to move a drive shaft (30) of the motor (31) forwardly so that the pinions (34, 35, 10 & 11) disengage and a cog (18) at the other end of the motor drive shaft (30) engages the two cogs (16, 17) for rotating two parallel leadscrews (13, 14). Simultaneous rotation of the leadscrews (13, 14) causes the chucks (6 & 7) to be interchanged at the front of the casing (2). A solenoid (38) holds the button (32) depressed until sensors (39) detect the presence of the new chuck at its forward position in front of the casing (2).</p> |
