Patent ID: 7296635
Filing Date: 2007-11-20
Classification: B25D

Abstract:
1. An electrically powered hammer comprising: a hammering mechanism; a rotatingly driven intermediate shaft including a set of drive teeth; a wobble drive arrangement for reciprocatingly driving the hammering mechanism, which wobble drive arrangement includes a wobble sleeve mounted on the intermediate shaft and the wobble sleeve includes a set of driven teeth; a mode change element selectively engageable, by movement along the intermediate shaft, such that when the mode change element is engaged with the drive teeth and the driven teeth then rotary drive is transmitted from the intermediate shaft to the wobble sleeve; the mode change element is formed integrally with an axial stop surface and the axial stop surface is engageable with a cooperating end stop surface formed integrally with one of the intermediate shaft and the wobble sleeve to limit the movement of the mode change element along the intermediate shaft; the mode change element including an engagement surface; and a mode change actuator including a cooperating engagement surface, and the mode change actuator is user selectable between a first position wherein the mode change element is engaged with both the drive teeth and the driven teeth and a second position wherein the mode change element is not engaged with the drive teeth, and when in the second position the cooprating engagement surface of the mode change actuator engages the engagement surface of the mode change element to prevent friction induced rotation of the wobble drive arrangement.