Patent ID: 6886730
Filing Date: 2005-05-03
Classification: B25C

Abstract:
1. A combustion-powered driving tool for driving fasteners into a workpiece, comprising: a housing having a first end and a second end opposite the first end; a head section for fixing to the first end of the housing and having a flammable gas channel formed therein; a motor; a battery for supplying an operating voltage; a motor drive controlling section that is supplied with the operating voltage of the battery and controls a voltage applied to the motor; a cylinder; a piston slidably movably disposed inside the cylinder; a combustion chamber frame that moves to contact and separate from the head section and that forms a combustion chamber together with the head section, the cylinder, and the piston when the combustion chamber frame is in contact with the head section; a fan rotatably disposed in the combustion chamber and driven to rotate by the motor; and a sparkplug exposed in the combustion chamber for igniting a mixture of air and flammable gas in the combustion chamber, the flammable gas being supplied into the combustion chamber via the flammable gas channel, wherein explosive combustion caused by firing of the sparkplug moves the piston toward the second end of the housing and a fastener is driven into the workpiece in accordance with the movement of the piston, wherein the motor drive control section applies a first voltage to the motor when the combustion chamber is formed by the combustion chamber frame moving toward and brought into contact with the head section, and a second voltage to the motor, the first voltage being greater than the second voltage.