Combustion-powered nail gun

A combustion-powered tool for driving a fastener into a workpiece, comprising:

• a combustion chamber selectively opened to atmosphere and closed to be hermetically sealed, fuel being introduced into the hermetically sealed combustion chamber;
• a fan rotatably disposed inside the combustion chamber for mixing the fuel with air to fill the combustion chamber with a fuel/air mixture;
• a spark plug exposed to the combustion chamber for igniting the fuel/air mixture within the hermetically sealed combustion chamber, wherein inner pressure of the combustion chamber increases when the fuel/air mixture is ignited within the hermetically sealed combustion chamber;
• a driver blade that is moved in accordance with the increase in the inner pressure of the combustion chamber, the fastener being driven into the workpiece caused by the increase in the inner pressure of the combustion chamber;
• a first switch that produces a first signal when a condition in which the combustion chamber is hermetically sealed is detected;
• a second switch that produces a second signal when manipulated by an operator;
• a third switch that is selectively turned ON and OFF;
• a battery connected to the fan and the spark plug;
• and
• a control unit that controls the spark plug to ignite the fuel/air mixture when both the first switch and the second switch are operated while the third switch is turned ON.