Abstract: 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.

Abstract: A compressed air exhaust arrangement in a pneumatic fastener driving tool. An exhaust port is formed in an upper portion of a main body, and a cover member is fixed onto the upper portion. An annular muffler member is disposed between the cover member and an upper surface of the main body to surround the exhaust port. The cover member has a lower surface formed with a plurality of cranked grooves for providing a plurality of air vent passages relative to an upper surface of the muffler member. The air vent passage allows the compressed air from the exhaust port to pass therethrough toward an atmosphere. Before freeze of the muffler member, most of the compressed air discharged through the exhaust port directly passes through the muffler member. After freeze of the muffler member, the compressed air passes through the air vent passage.

Abstract: A pneumatic nailing machine having a driving depth adjusting mechanism disposed near a trigger. A push lever is vertically movably supported around a nose portion and extends near the trigger. The push lever is divided into an upper section and a lower section, the dividing portion being near the trigger. A cam shaft having first and second cam lobes are rotatably provided near the trigger. A lowermost end of the upper section is in slide contact with the first cam lobe, and an uppermost end of the lower section is in slide contact with the second cam lobe. The cam shaft together with the cam lobes, and the upper and lower sections are concurrently movably supported by a guide plate supported by a main body. By rotating the cam shaft in one direction, a distance between the lowermost and uppermost ends is increased to expand entire length of the push lever.

Abstract: A pneumatic nailing machine having a, driving depth controlling mechanism. The pneumatic nailing machine includes a push lever having a lower end in pressure contact with a workpiece and another end in association with a trigger. Vertical moving length of the push lever relative to a nose will change the driving depth. An eccentric body is rotatably supported on the main body. The eccentric body is positioned above the upper tip of the push lever and the upper position of the upper tip of the push lever is regulated by the eccentric body. If the eccentric body is angularly rotated to a first angular position, the push lever can be moved to its highest position for providing a minimum distance between the lower tip of the push lever and a lower tip of the nose to provide the maximum driving depth. If the eccentric body is angularly rotated to a second angular position, the distance between these tips become maximum to provide a minimum driving depth.

Abstract: A sharpshooting nail gun capable of driving a nail into an intended spot. The nail gun includes a bit guide having an injection groove through which a nail and a drive bit pass. A contact arm is movably supported to the bit guide. The contact arm has a lower tapered end portion abuttable against a wall or attachment member, and an upper portion engageable with a trigger. When the contact arm is biased toward the wall, the upper portion is disengaged from the trigger for allowing the trigger to be manipulatable. The lower portion of the contact arm protrudes from a lower end of the bit guide, and is provided with an injection bore extending in alignment with the injection groove.