| 摘要 |
<p>There is described in this disclosure, an improved air replenishing and idling system for a reciprocating hammer type tool having an outer housing and reciprocal drive means which comprises an elongated barrel mounted within that housing. The barrel includes an axially disposed, air passageway means. Slideably positioned within the barrel is a piston member which includes a closed end portion and a hollow, tubular forward portion having first and second air passageways. The piston is reciprocally moved within the barrel by the drive means. Slideably positioned within the hollow tubular portion of the piston is an impact ram. In the operational mode, the ram, tubular portion of the piston member, and barrel cooperate to seal or expose the first and second air passageways and provide a communicative path to the "outside" air through the barrel air passageway means whereby the ram is urged axially towards and away from the tool bit through the pressure differentials created. Further, in the idling mode, the first and second air passageways and the barrel passageway means insure that the ram is inactive when the tool bit is removed or when the tool is lifted from the work surface.</p> |
