Patent ID: 7814871

Claim:
A portable powered device, comprising: a housing; a main combustion chamber within the housing for combustion of a mixture of a fuel and a combustion-supporting gas, the combustion chamber being defined by the housing and by a baffle plate; a priming piston in the housing on a side of the baffle plate opposite the main combustion chamber to compress the mixture of a fuel and a combustion-supporting gas to a pressure in excess of ambient atmospheric pressure prior to combustion; a subsidiary combustion chamber within the housing for combustion of a second mixture of a fuel and a combustion-supporting gas, the subsidiary combustion chamber being defined by the priming piston; a work piston, extending from the baffle plate, which performs the work required of the device; the work piston and the priming piston being separately movable in response, directly or indirectly, to combustion of the mixture of the fuel and combustion-supporting gas in the main combustion chamber and the subsidiary combustion chamber; and whereby energy released by combustion of the fuel and the combustion-supporting gas in the subsidiary combustion chamber is used to compress a mixture of the fuel and combustion-supporting gas in the main combustion chamber to ready the device for displacement of the work piston.