A nail gun having a contact arm normally biased in a direction away from a workpiece by compression springs. A free end of the contact arm is brought into abutment with a workpiece and a trigger is pulled for driving a nail thereinto. In the trigger pulling operation, an inner end of the contact arm is engaged with a trigger arm which is biased by a plunger spring through a plunger. Because the contact arm is held on the workpiece, the plunger is moved to provide ON state against biasing force of the plunger spring. Immediately after the nail driving, a nail gun body is moved in a direction away from the workpiece relative to the contact arm. This causes disengagement of the trigger arm from the inner end, to relatively move the nail gun body toward the workpiece by the biasing force of the compression springs. This means relative movement of the contact arm in the direction away from the workpiece. If the trigger is released, the trigger arm is again brought into engagement with the inner end, because the trigger arm is normally urged toward the inner end by a trigger arm spring.

A nail gun has a free end 19a and central potion of a trigger arm 19 positioned within a trigger 11, on an upper end 12a of a safety portion 12 and at a plunger 17, respectively. When the trigger 11 is pivoted on its pivot end 16, pivoting movement of the trigger 11 moves a pivot end 18 of the trigger arm 19 to press the central portion of the trigger arm 19 into contact with the plunger 17 and, with the plunger 17 serving as a fulcrum, to press the free end 19a downward against the upper end 12a of the safety portion 12. If downward movement of the safety portion 12 is obstructed when the trigger 11 is pivoted, the upper end 12a contacted by the free end 19a of the trigger arm 19 serves as a fulcrum around which the trigger arm 19 pivots with movement of the trigger 11, whereupon the central portion of the trigger arm 19 presses the plunger 17 inward so that an activation switch 10 activates a blade 7 to eject a nail through a nose piece 5.

A nail gun has a free end 19a and central potion of a trigger arm 19 positioned within a trigger 11, on an upper end 12a of a safety portion 12 and at a plunger 17, respectively. When the trigger 11 is pivoted on its pivot end 16, pivoting movement of the trigger 11 moves a pivot end 18 of the trigger arm 19 to press the central portion of the trigger arm 19 into contact with the plunger 17 and, with the plunger 17 serving as a fulcrum, to press the free end 19a downward against the upper end 12a of the safety portion 12. If downward movement of the safety portion 12 is obstructed when the trigger 11 is pivoted, the upper end 12a contacted by the free end 19a of the trigger arm 19 serves as a fulcrum around which the trigger arm 19 pivots with movement of the trigger 11, whereupon the central portion of the trigger arm 19 presses the plunger 17 inward so that an activation switch 10 activates a blade 7 to eject a nail through a nose piece 5.

An adjustable angle magazine provides the operator of a nail gun the ability to adjust the position of a housing of the magazine, which stores nails to be driven, relative to a nose casting of the nail gun. This repositioning enables an operator to employ a variety of nails, collated at a variety of angles, within the nail gun.

The present invention provides a head valve assembly for a pneumatic fastener including a piston assembly reciprocated within a cylinder assembly for driving a fastener and a housing having an end cap for at least partially enclosing the head valve assembly. The head valve assembly includes a valve piston for causing supply pressure to be ported to the piston assembly for moving the piston assembly within the cylinder assembly from a non-actuated position to an actuated position for driving the fastener. Further, an inner cap is disposed within the end cap around the valve piston. The inner cap includes an inlet port for porting pressure to the valve piston. In addition, a main seal is coupled to the valve piston for sealing the cylinder assembly from supply pressure while pressure is ported to the valve piston by the inner cap for holding the piston assembly in the non-actuated position. The main seal seals pressure ported to the valve piston by the inner cap from supply pressure ported to the piston assembly.