Device for improving the deactivation response of an electropneumatic percussive tool

摘要

The method involves increasing the pressure between the fly piston (14) and exciter piston (12) when the drill is lifted away from the ground in order to reduce the knock-on effect of the fly piston. Independent claim describes excavating machine such as a drilling hammer which has a valve mechanism (30) which can be activated when the machine is lifted from the substrate so that the pressure in the impact mechanism (10) acting between the fly and exciter piston is increased.