Abstract: In a combustion-powered fastener driving tool employing a fuel cell having an internal fuel metering valve with an axially reciprocating delivery stem, an actuator is provided for causing the dispensing of a desired dose of fuel from the fuel cell prior to each combustion event, the actuator including at least one actuator element configured for exerting an axial force on the stem, releasing the dose of fuel, and a fuel conduit associated with the element and being in fluid communication with the stem for transmitting the fuel for delivery to a combustion engine.

Abstract: A fuel cell for use with a combustion tool for delivery of a predetermined amount of fuel with each stem actuation is provided and includes a housing defining an open end enclosed by a closure. A main valve stem has an outlet, disposed in operational relationship to the open end and reciprocating relative to the housing at least between a closed position wherein the stem is relatively extended, and an open position wherein the stem is relatively retracted. A fuel metering valve is located within the housing, associated with the main valve stem, including a fuel metering chamber disposed in close proximity to the closure and configured so that when the stem is in the open position, only a measured amount of fuel is dispensed through the outlet. In a preferred embodiment, the fuel cell housing includes a separate fuel container, and the fuel metering valve includes a valve body having a second end opposite the fuel metering chamber located within the container.

Abstract: In a powered tool for dimpling a drywall panel and driving a drywall nail through such panel, into a substrate, a dimpler mounted to a nosepiece of the tool so as to be axially movable over a limited range has an annular portion disposed axially beyond the nosepiece. The tool includes a piston and a driving blade joined to the piston and arranged for driving a drywall nail through the nosepiece and the annular portion, for engaging the annular portion near a distal end of the driving blade, and for driving the dimpler outwardly when the piston is impelled from a retracted position toward an advanced position. The annular portion has a frusto-conical bore. The driving blade has a frusto-conical tip fitting thereinto. A workpiece-contacting shoe is adjustable between a right-angled position relative to the drywall panel and an acute-angled position.