| 摘要 |
An electric hand tool has a mode changing device comprising a clutch device which is engaged and disengaged by an axial movement of a layshaft 10. The clutch device comprises a toothed sleeve 13 having coupling bodies, e.g. balls 18, which, depending on the axial position of the layshaft 10, engage drive bearing 11 that drives a wobble finger 26 which converts rotational movement of the drive bearing 11 into an axial, percussive movement. The toothed sleeve 13 via plug-in gearing 31 comprising external/internal gearing 15, 14 also drives the layshaft 10 when the electric hand tool is in drilling and impact drilling mode. When impact mode only is selected the external/internal gearing 15, 14 is disengaged (see fig 2) and when in impact mode only the balls 18 are accommodated in a constriction, e.g. recess 29, in the layshaft 10. A gear 24 mounted on the layshaft engages a gear 25 fixed to a spindle 23 which drives a tool. Gear 24 may also engage locking means 21 when the percussion only mode is selected. |
