Patent ID: 7905379

Claim:
A hammer-drive powder-actuated tool comprising: a tubular housing having front and rear open ends opposite to each other in an axis, an inner annular surface, and an inner engaging flange extending inwardly and radially from said inner annular surface and disposed adjacent to said rear open end; a barrel unit inserted movably into said housing through said front open end and having a rear end portion that defines a chamber adapted for accommodating powder load therein; and a firing unit including a firing pin holder disposed fixedly in said housing, and formed with a through hole, a firing pin disposed movably between said rear open end of said housing and said rear end portion of said barrel unit, said firing pin having a firing end portion that extends into said through hole in said firing pin holder, an enlarged head portion opposite to said firing end portion in the axis and disposed adjacent to said rear open end of said housing, an intermediate portion interconnecting integrally said head portion and said firing end portion, and an annular shoulder portion disposed at a junction of said firing end portion and said intermediate portion, said firing pin being operable between a normal position, where said firing end portion is spaced apart from the powder load in said chamber in said rear end portion of said barrel unit, and a firing position, where said firing end portion contacts and ignites the powder load in said chamber in said rear end portion of said barrel unit, an engaging member sleeved on said intermediate portion of said firing pin, and engaged between and abutting against said inner engaging flange of said housing and said firing pin holder so as to stop movement of said firing end portion of said firing pin away from said through hole in said firing pin holder, and a biasing member disposed in said housing and having opposite ends abutting respectively against said head portion of said firing pin and said engaging member for biasing said firing pin to move toward the normal position, thereby enabling said annular shoulder portion of said firing pin to abut against said engaging member.