Hitachi Koki Co., Ltd.

Toshifumi Kubota

Tsunehisa Terayama

Shinki Ohtsu

Takuji Torii

Mitsuhiro Sunaoshi

Yo Kawakami

Hiromu Utsumi

Teruo Suzuki

Yoshinori Ishizawa

Akira Uno

Mitsuo Ogura

Tsukasa Suzuura

Mitsuyuki Ishikawa

Yoshimitsu Kawasaki

Seki Moriguchi

Yasuyuki Hirano

A motor and a power transmitting mechanism are accommodated and supported in a two-piece housing unit separable into first and second housings. An air tank is defined by an outer surface of the second housing and an inside surface of a third housing provided on a recessed outer surface of the second housing.

Portable compressor

An air compression system for supplying a compressed air into a pneumatically operated tool. The system includes an air compressor and air accumulator connected to the compressor and having a first accumulator and a second accumulators separate therefrom. A relief valve is connected between the first and second accumulators for allowing the compressed air to flow from the first accumulator to the second accumulator when a pressure of the compressed air accumulated in the first accumulator increases to a predetermined pressure. A check valve is provided between the first and second accumulators and in parallel to the relief valve for allowing the compressed air to flow from the second accumulator to the first accumulator. The accumulator is connected to the pneumatically operated too. If the tool requires small amount of compressed air for operation, the compressed air supply into the first accumulator is only necessary to reduce recharging period.

Air compression system having two separate compressed air accumulators

A combustion gas powered tool includes a member defining a part of cylindrical combustion chamber having an axis. A piston is movable in a direction along the axis of the combustion chamber. The piston defines the combustion chamber in conjunction with the member. A mixture of air and fuel is generated in the combustion chamber. The air-fuel mixture in the combustion chamber is burned to drive the piston. An orifice grille extends in the combustion chamber, and is parallel to the axis of the combustion chamber.

Combustion gas powered tool

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.

Combustion gas powered fastener driving tool

An automatic nailing apparatus includes a housing having a piston driving system for driving a piston, a percussion rod having a concave at only the tip thereof, a nosepiece having a round channel being provided with a pair of nail head guide rails, and a nail magazine for supplying interconnected nails. The forefront nail of the interconnected nails can be nailed in a direction normal to a workpiece because a point of application on nailing exists on the center axis of the forefront nail.

Automatic nailing apparatus with improved percussion rod and nosepiece

In a mowing machine having an engine for driving a rotary blade via a centrifugal clutch, a shaft and a reduction gear assembly, the outer diameter of the shaft is selected such that the torsional natural vibration frequency of the rotational system extending from the engine to the rotary blade is less than one third of a rotational frequency above which the centrifugal clutch starts transmitting the engine output torque to the shaft. As a result, the torsional natural vibration frequency of the rotational system does not equal the rotational frequency or the half or one third of the rotational frequency of the engine so that undesirable resonance phenomenon will not occur.

Growing community of inventors

Katsuta, Japan

Toshifumi Kubota