Self-starting portable tool with linear motor

An efficient, portable, easy to operate tool employing a linear motor (130) is disclosed that is powered by the gases produced from the internal combustion of a fuel and air mixture. A supply of liquified gas stored under pressure in a cylinder (104) provides the source of power. The linear motor (130) is slidably mounted within a cylinder (104) to move reciprocally downwardly and upwardly through a driving and return stroke. A combustion chamber (120) is formed at the upper end of the cylinder (104). A spark plug (164) powered by a piezo-electric firing device (182) is located within the combustion chamber (30). The combustion chamber (120) features a turbulence generator, such as a fan (122), driven by an electric motor (122) which is continuously in operation when the tool is in use. A main valve mechanism (136) actuated by a set of lifting rods (144A, 144B) that are moved upwardly and downwardly when the tool is moved towards and away from the workpiece, is used to control the opening and closing of the combustion chamber (120) and to control the flow of fresh airthrough the combustion chamber (120). When the combustion chamber (120) is isolated from the atmosphere and the fuel and air are thoroughly mixed, the spark plug (164) is fired to explode the fuel and air mixture and force the linear motor (130) through its driving stroke. The linear motor (130) is returned to its driving position by a spring (148) or air acting against the underside of the linear motor (130). The unique use of the electric fan (122) improves the overall operational efficiency of the tool and the utilization of the liquified combustible gas. -->