Abstract: A power actuated tool for driving a fastener such as a pin or nail into a substrate, has a fastener guide mounted at the forward end of a body of the tool for displacement axially inwardly relative to the body when the forward end of the tool is pressed against a substrate whereby to permit firing of the tool. A magazine carried by the tool for containing a plurality of fasteners mounted seriatim on segments of a carrier strip advances the leading end of the carrier strip and the fastener carried thereby into the fastener guide. A locking system for impeding firing of the tool is releasable in response to the presence of a fastener and associated segment of the carrier strip within the fastener guide whereby to permit firing of the tool only when a fastener is present within the fastener guide. The locking system thereby acts to prevent firing of the tool when the magazine is empty of fasteners and which could otherwise lead to damage occurring to the tool.

Abstract: The barrel of a power actuated tool for driving a fastener into a substrate upon detonation of an explosive charge, comprises front (4) and rear (2) barrel sections mounted for telescopic movement to absorb recoil upon firing. The sections are held in assembled relation by a retainer element (14) and are such that assembly and disassembly can occur by manipulation of one barrel section relative to other without the need to remove the retainer element (14).

Abstract: A power actuated tool for driving a fastener into a work surface includes a firing pin for firing an explosive charge to drive the fastener. The firing pin is held in a cocked position against a spring bias by a rotary sear which is displaced rearwardly during cocking by pressing a barrel against the work surface. In the cocked condition, the sear is aligned with a trigger mechanism which can be actuated to pivot the sear and thereby cause release of the firing pin which is then driven by the spring bias to fire the charge.

Abstract: An explosively-actuated fastener setting tool comprises a barrel which can be moved forwardly after firing in order to open a breach for loading of a fresh charge. Forwards movement of the barrel also enables a spring-loaded stop to pivot through a slot in the barrel and engage the head of a firing piston to thereby reset the piston in the barrel. In the normal, breach-closed position of the barrel, the stop is fully retracted from the barrel. The configuration permits increased opening movement of the barrel. Further stops between the barrel and tool body engage in a forward position of the barrel to prevent the rear end of the barrel slot from impacting against the pivotal stop.