Patent ID: 6695195
Filing Date: 2004-02-24
Classification: B25C

Abstract:
A combustion-powered tool for driving an item into a work piece, the combustion-powered tool comprising:a housing having an upper end, a lower end, an inner surface, and an outer surface; a push lever that is supported at the lower end of the housing; a combustion chamber wall disposed within the housing, the combustion chamber wall having an inner surface, an outer surface, an upper end, and a lower end, the inner surface of the combustion chamber wall substantially defining a combustion chamber, the outer surface of the combustion chamber wall being in confrontation with the inner surface of the housing and separated from the inner surface of the housing by a space, the combustion chamber wall having an inlet in the upper end and an outlet in the lower end, the combustion chamber wall moving vertically within the housing in a ganged manner with the push lever between an open position wherein the inlet and the outlet are opened and a sealed position wherein the inlet and the outlet are closed; a cylinder disposed below and in fluid communication with the combustion chamber; a piston that is disposed in the cylinder and that partially defines the combustion chamber with the combustion chamber wall, the piston being capable of vertical movement guided by the cylinder; an item setting unit that is disposed at the lower end of the housing and that sets the item in a position below the piston; a gas injection unit that injects combustible gas into the combustion chamber; a drive start unit that ignites and explodes the combustible gas injected into the combustion chamber, the piston being driven downward in the cylinder by resultant expansion of gas in the combustion chamber and driving the item set in the item setting unit downward; and a blocking member that blocks air from flowing between the upper end of the housing and the lower end of the combustion chamber wall through the space between the inner surface of the housing and outer surface of the combustion chamber.