Patent ID: 6196330
Filing Date: 2001-03-06
Classification: B25D

Abstract:
A manually operable drilling tool (1) comprising a housing (2), a chuck (6) fitted on said housing and having an axis of rotation (A), a tool bit (7) secured in said chuck for rotation about the axis of rotation, an electro-pneumatic first striking mechanism (16) positioned in said housing (2) and arranged to periodically transfer axially directed impacts to said tool bit (7) via a free piston, a selectively operable spring-biased means, second striking mechanism (20) located within said housing and arranged to transfer axially directed impacts to said tool bit (7), said second striking mechanism spaced axially from said first striking mechanism and formed of a separate arrangement of parts from said first striking mechanism and having an impact energy and an impact frequency different from an impact energy and an impact frequency of said first striking mechanism, and said first and second striking mechanisms being operable together or separately.