Hitachi Koki Co., Ltd.

Koki Holdings Co., Ltd.

Hideki Yamada

Yoshiki Aoki

Shinichirou Satou

Tsukasa Suzuura

Masanori Okada

Shinichi Kakefuda

Rui Akiba

Hideyuki Hashimoto

Yuta Noguchi

Takahiro Ookubo

Satoshi Abe

Provided is an electric tool with which work efficiency can be improved. A controller of an electric tool can execute: a first control, whereby during a non-operating state after a motor has started up and before a tip tool is set to be in an operating state, the motor is driven at a slow idling rotation speed, and when the tip tool is set to be in the operating state, the motor is driven at a normal rotation speed which is higher than the slow idling rotation speed; and a second control, whereby in a case where a trigger switch has been turned off in a state where the motor is being driven at the normal rotation speed and the trigger switch is thereafter turned on again under a prescribed condition, the motor is driven at the normal rotation speed regardless of the state of the tip tool.

Electric tool

An impact tool includes a casing () supporting a tip tool (), a piston () provided in the casing (), an electric motor () provided in the casing (), a motion converting mechanism () provided in the casing (), and a vibration reducing mechanism () provided in the casing (). The vibration reducing mechanism () has a supporting member, which is swingable with using a fixing position (J) as a supporting point and a weight () attached to a free end side of the supporting member. In a plane including a center line (C), the gravity center (H) of the weight () and the gravity center (G) of the casing () are disposed at mutually different locations, and the fixing position (J) is disposed on the side of the gravity center (G) relative to the center line (C).

Impact tool

Portable electric hammer drill

A spring clutch mechanism for transmitting a driving force of a driving part to a driven part, including a first part, a second part, and a spring disposed between the first part and the second part. The first part is connected to the driven part. The second part is connected to the driving part and is rotatable relative to the first part coaxially therewith. The first part has a first end provided with a frusto-conical portion having a first tapered surface, and the second part has a second end formed with a recess provided with a second tapered surface in contact with the first tapered surface. the first part and the second part are aligned linearly and coaxially in a state that the first end is inserted into the second end maintaining contact of the first tapered surface with the second tapered surface.

Spring clutch mechanism in screw driver

A screw driver capable of avoiding co-rotation of an end bit and a motor in case of sharp shooting the end bit with a groove in a head of a screw. A co-rotation preventing mechanism is engageable with an end bit mounting portion when the end bit mounting portion is at a frontward position to prevent the end bit mounting portion from being rotated in the forward direction and to allow the end bit mounting portion to rotate in the reverse direction. The preventing mechanism is disengageable from the end bit mounting portion when the end bit mounting portion is at the rearward position to allow the end bit mounting portion to rotate in both forward and reverse directions.

Screw driver

Growing community of inventors

Hitachinaka, Japan

Hideki Yamada