Abstract: A pneumatically operated nail gun having an arrangement for preventing a cylinder from floating due to impact of a piston against a piston bumper. When the piston is pneumatically moved toward its lower dead center for nail driving, the piston strikes against the piston bumper. The bumper generates a force for urging the cylinder toward top dead center of the piston. A plurality of ribs provided with seat portions protrude radially outwardly from the cylinder and spaced away from each other in a circumferential direction thereof. A lower end of a separator, which interconnects a main housing with an exhaust cover, is positioned above each seat portion of each rib. A metal washer is seated on the seat portions, and a flexible damper ring is mounted on the washer and below the lower end of the separator. Upward force of the cylinder is moderated and dampened by the damper ring.

Abstract: A plunger is shiftable in response to a trigger operation by a user. A valve piston has a valve piston chamber therein for slidably accommodating the plunger and an axial bore into which the plunger is inserted. An air passage connects the valve piston chamber to an atmosphere via a clearance between the plunger and the axial bore of the valve piston. A seal member is provided to seal the clearance between the plunger and the axial bore of the valve piston. And, a relief passage is formed on at least one of the plunger and the axial bore of the valve piston to open the air passage, thereby allowing compressed air to exit from the valve piston chamber to the atmosphere under a condition where the plunger is engaged with the axial bore of the valve piston.

Abstract: A pneumatically powered nail gun having a duster mechanism which is also pneumatically powered with the same pneumatic source. The nail gun includes a main body having a lower end and defines therein a compressed air chamber. A cylinder piston arrangement is disposed in the main body, and the compressed air is selectively applied to the piston for moving a driver blade connected to the piston to drive a nail. The duster mechanism includes a duster nozzle provided at the main body for ejecting a compressed air therethrough. A pressure release valve is disposed at an air passage extending between the duster nozzle and the compressed air chamber for selectively shutting off a fluid communication therebetween. A pressure regulating section is disposed at the air passage for providing a compressed air passing through the duster nozzle at a pressure lower than that in the compressed air chamber.

Abstract: A pneumatically operated nail gun having an arrangement for preventing a cylinder from floating due to impact of a piston against a piston bumper. When the piston is pneumatically moved toward its lower dead center for nail driving, the piston strikes against the piston bumper. The bumper generates a force for urging the cylinder toward top dead center of the piston. A plurality of ribs provided with seat portions protrude radially outwardly from the cylinder and spaced away from each other in a circumferential direction thereof. A lower end of a separator, which interconnects a main housing with an exhaust cover, is positioned above each seat portion of each rib. A metal washer is seated on the seat portions, and a flexible damper ring is mounted on the washer and below the lower end of the separator. Upward force of the cylinder is moderated and dampened by the damper ring.

Abstract: An air plug assembled into a pneumatically operated tool. The air plug is detachably connected to an air coupler which is connected to a compressed air source through a hose. When the air plug is disconnected from the air coupler, one end of the air plug is utilized as an oil supply portion. The air plug is formed with an air passage extending throughout a length of the air plug. The one end of the air plug is formed with an air inlet hole also serving as an oil supply hole for maintenance to the pneumatically operated tool. The oil supply hole has a conical shape increasing its inner diameter toward the one distal end. The conical configuration of the oil supply hole provides a maximum inner diameter at the open end which is not more than twice as large as a diameter of a tip end of a nozzle of a lubricator.

Abstract: A plunger is shiftable in response to a trigger operation by a user. A valve piston has a valve piston chamber therein for slidably accommodating the plunger and an axial bore into which the plunger is inserted. An air passage connects the valve piston chamber to an atmosphere via a clearance between the plunger and the axial bore of the valve piston. A seal member is provided to seal the clearance between the plunger and the axial bore of the valve piston. And, a relief passage is formed on at least one of the plunger and the axial bore of the valve piston to open the air passage, thereby allowing compressed air to exit from the valve piston chamber to the atmosphere under a condition where the plunger is engaged with the axial bore of the valve piston.

Abstract: A pusher piston shifts a nail by a predetermined distance along an eject hole before a driver blade drives the nail. In this case, the predetermined shifting distance of the pusher piston satisfies a requirement that the tip of the nail protrudes out of the eject hole while the nail itself is not removed off a band member. Thus, the nail is surely held by the band member even when the nail is positioned at the pushed-out position where the tip of the nail protrudes out of the eject hole.

Abstract: A repetitive striking type pneumatically operated nail gun for repeatedly striking, by a drive bit, a head of a nail for sinking the nail into a workpiece. The drive bit is connected to a piston reciprocally movably disposed in a cylinder. A return chamber is provided around the cylinder and in communication therewith. A head valve chamber is provided at a position above a head valve disposed above the cylinder. A drive air is provided for selectively applying compressed air to the head valve chamber or into the cylinder. A repetitive valve chamber is provided for providing selective communication with the return valve, the head valve chamber and a trigger valve. A cylinder guide is provided which prevents the cylinder from being moved in its axial direction in a case where the pressure within the return chamber becomes higher than that in the drive air chamber. A partition segment is provided to the cylinder guide for separating the return chamber from the drive air chamber.

Abstract: A percussion tool comprises a cylinder 3 communicated to a pressure accumulating chamber 16 storing pressurized air therein, and a piston 4 slidable in the cylinder 3 when pressurized air is introduced into the cylinder 3 from the pressure accumulating chamber 16 and pressure of the introduced air is applied on the piston 4. A circular groove 6 is recessed on a peripheral surface of the piston 4, the peripheral surface adjacently facing to an inside wall of the cylinder 3. A piston ring 10 is accommodated in the circular groove 6, so as to provide a hermetical sealing between the piston 4 and the cylinder 3. And, a ring bumper 11 made of resilient member is provided in the circular groove 6 adjacent to the piston ring 10 in a sliding direction of the piston 4.

Abstract: A percussion tool comprises a cylinder 6 provided in a percussion tool body 1, and a piston 8 accommodated in the cylinder 6 and slidable in an axial direction of the cylinder pressure of pressurized air. A nail guide 10, provided at a front end of the percussion tool body 1, is formed into a hollow cylindrical shape capable of loading a nail 12 therein. A retaining region 15 is formed on an inner wall of the nail guide 10. A permanent magnet 19 is disposed in the retaining region 15 for magnetically holding a shaft of the nail 12 loaded in the nail guide 10. A stepdown region 14 is formed on the inner wall of the nail guide 10 inwardly than the retaining region 15 in an axial direction of the nail guide 10, so that the loaded nail 12 is aligned in parallel with a nail hitting direction. A slant surface 16 smoothly connects the stepdown region 4 to the retaining region 15.

Abstract: A pneumatically operated nail gun having a safety device which prevents a trigger lever from being accidentally manipulated. The gun has a nail guide movably disposed over a bit guide. A movable segment having a pipe-shaped portion and an arm portion formed integrally therewith is provided. The pipe-shaped portion is disposed movably in the nail guide, and the arm portion is movable in a slit of the nail guide. The arm portion is coupled to the safety arm whose end portion is engageable with the trigger lever. A spring is provided to urge the safety arm in a direction to maintain engagement between the end portion and the trigger lever. When the nail inserted in the nail guide is depressed onto the workpiece, the pipe-shaped portion moves against the biasing force of the spring, so that the end portion of the safety arm disengages from the trigger lever, whereupon the trigger lever can be operated.

Abstract: A combustion gas powered fastener driving tool includes inlet and outlet openings through which the combustion gases are discharged from a combustion chamber. These openings are located above the uppermost driving position (top dead center) of a slidable piston, so that an air and fuel mixture is fully trapped in the combustion chamber until after it is combusted. Since an outflow of the unburnt air and fuel mixture is completely prevented, the rate of fuel consumption of the fastener driving tool is high and there is no danger of accidental explosion of unburned fuel even when the fastener driving tool is used in a badly ventilated working place or site. An electric fan for forcing fresh air into the combustion chamber is disposed outside the cylinder and isolated from high temperatures. The fan is durable in structure and reliable in operation.