| 摘要 |
1484659 Percussive drills ROBERT BOSCH GmbH 11 Sept 1975 [16 Oct 1974] 37448/75 Heading B4C A percussive hand tool comprises a motor 2 a striker 23, a driving member 24 which moves the striker through an air cushion and is driven by a cam follower 20 from a cam 17 having a continuous track arranged for rotation by the motor. The percussive action can be stopped by actuation of a bayonet type member 33 which allows the tool holder to move out of the way of the striker. In modifications a conical clutch may be provided to connect the drive cam to its shaft or release it therefrom to prevent percussive action or a dog clutch arrangement may be provided on the cylinder containing the drive pistons. |
