Patent ID: 7014085

Claim:
An explosively actuated tool, comprising: a casing; a handle being moveable relative to and projecting from a rear end of said casing; a barrel which projects from a front end of said casing and from which a fastener is to be fired by firing of an explosive charge; a firing mechanism actuable by forward displacement of the handle to a firing position; and a safety lock device for inhibiting actuation of the firing mechanism when the barrel is orientated substantially horizontally or downwardly from the horizontal, said lock device comprising a locking ball moveable under gravity in response to the orientation of the barrel, into a locking position in which said ball inhibits actuation of the firing mechanism; wherein said ball is captive in a space defined between a front end of said handle and the rear end of said casing; the front end of said handle comprises a forwardly projecting portion and a chamber adjacent said forwardly projecting portion; said ball assumes the locking position when said ball is located between the forwardly projecting portion and a rear face of the rear end of said casing and prevents further forward displacement of said handle toward the firing position; said ball assumes a releasing position when said ball is located in said chamber without preventing forward displacement of said handle up to the firing position; and the front end of said handle further comprises a leading surface connecting the forwardly projecting portion and the chamber, said leading surface being inclined relative to an axial direction of said barrel sufficiently to cause said ball to roll under gravity from the releasing position to the locking position when said barrel is oriented horizontally.