Makita Corporation

Kenji Kobayashi

Takuya Kusakawa

Shinji Hirabayashi

Tokuo Hirabayashi

Sadaharu Oki

Tadasuke Matsuno

Embodiments of the present invention may include a power tool including a drive motor and a continuously variable transmission mechanism. The continuously variable transmission mechanism may include a sun roller rotated by a drive motor, the sun roller configured to press on a plurality of planetary rollers, a holder radially supporting the plurality of planetary rollers, a shift ring being in internal contact with the plurality of planetary rollers, and a resistance reducing portion disposed at the holder to fill a gap between the two of the planetary rollers.

Power tool

It is an object of the invention to provide a useful technique for reducing vibration of a handgrip and improving the cutting efficiency while achieving weight reduction of a reciprocating power tool. According to the invention, a representative reciprocating power tool is provided to comprise a body, a tool bit, an actuating mechanism, a handgrip. The handgrip and the body can rotate with respect to each other via a pivot in a direction crossing the direction of reciprocating linear motion of the tool bit. An elastic element is disposed between the handgrip and the body and serves to absorb vibration transmitted from the body to the handgrip by elastically receiving the relative rotation of the handgrip and the body. According to the invention, vibration in the handgrip can be reduced and the cutting efficiency can be improved without complicating the construction.

Reciprocating power tool

Power tool with vibration reduction

It is an object of the present invention to provide a useful technique for effectively reducing vibration in a reciprocating power tool with a simple structure. According to the present invention, a representative reciprocating power tool includes a motor, a tool bit, a slider, a motion converting mechanism and a counter weight. The tool bit performs a predetermined operation by reciprocating. The slider reciprocates to drive the tool bit. The motion converting mechanism converts a rotating output of the motor into a reciprocating movement of the slider. The counter weight is provided in the motion converting mechanism. Further, the counter weight reciprocates in a direction opposite to the reciprocating direction of the slider. The phase difference between the reciprocating movement of the slider and the reciprocating movement of the counter weight is set such that a time lag is provided between the instant when the slider reaches a top dead center and the instant when the counter weight reaches a bottom dead center. With such construction, timing for reducing the kinetic energy caused by the reciprocating movement of the slider can be optimized, taking into account a cutting resistance that the tool bit receives from the workpiece during operation.

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Anjo, Japan

Kenji Kobayashi