초록 ▼

A speed-increasing mechanism and a clutch mechanism are provided between a speed-reduction gear train and planetary gear trains, to realize a small-torque and high-speed rotation during a light load condition and a large-torque and low-speed rotation during a heavy load condition. A motor is actuate

A speed-increasing mechanism and a clutch mechanism are provided between a speed-reduction gear train and planetary gear trains, to realize a small-torque and high-speed rotation during a light load condition and a large-torque and low-speed rotation during a heavy load condition. A motor is actuated by a relay. An auxiliary motor switch, closing a contact of the relay, is provided at a motor housing to facilitate an operation of a shear wrench during a work where a bolt is fastened upward from below.

대표청구항 ▼

[ What is claimed is:] [1.] A cordless shear wrench comprising:a motor driven by a battery;a speed-reduction gear train and a plurality of planetary gear trains reducing the rotational speed of said motor;socket means for rotating and fastening a bolt with an associated nut by a torque transmitted b

[ What is claimed is:] [1.] A cordless shear wrench comprising:a motor driven by a battery;a speed-reduction gear train and a plurality of planetary gear trains reducing the rotational speed of said motor;socket means for rotating and fastening a bolt with an associated nut by a torque transmitted by said speed-reduction gear train and said plurality of planetary gear trains;a speed-increasing gear mechanism disposed in a gear arrangement connecting said motor and said socket means, said speed-increasing gear mechanism having an input member and an output ember connected via a one-way clutch; anda clutch mechanism provided to allow a slip at a predetermined portion in said speed-increasing gear mechanism when a load exceeds a predetermined value, thereby transmitting no torque to said output member from said input member through said speed-increasing mechanism.