Koki Holdings Co., Ltd.

Kengo Tamura

Junichi Toukairin

Shota Takeuchi

Yoshihiro Komuro

Takuhiro Murakami

Masaru Hirano

In a working device, a cover added outside an enclosure portion is used to utilize vibration of the working device during an operation thereof to cool the enclosure portion. The working device has: a motor; a speed reduction mechanism for decelerating rotation of the motor; a striking mechanism; an enclosure portion (main body housing, hammer case) accommodating them; and a cover covering at least a portion of an outer surface of the enclosure portion. An airflow passage is formed between an outer surface of the hammer case and the cover and is configured so as to allow inflow and outflow of outside air. The cover is held so as to be slightly movable by sandwiching an elastic member in an axial line direction and, by the cover being moving forward and backward during its operation, air goes into or comes out of the airflow passage to cool the hammer case.

Working device

An impact tool includes a hammer that is rotated by a motor and energized toward a front side from a spindle by a cam mechanism and a spring, and an anvil that is struck by the hammer. The hammer includes a main body part, and claw parts extending forward from the main body part, and tapered surfaces are formed such that an inner diameter side end of each of the claw parts of the main body part is located on the front side relative to an outer diameter side end of the claw part. The tapered surfaces are formed, on an outer peripheral side of a front facing surface of the hammer, in such a shape that the tapered surfaces recede as separating in a radial direction from a rotation axis.

Impact tool

An electric tool to restrain stress concentration is provided. The electric tool includes a housing (), a motor (), an anvil (), and an impact mechanism (). The motor is accommodated in the housing and rotatable. The anvil supported by the housing and rotatable about an axis (A). The impact mechanism is configured to convert a rotational force generated by the motor into a rotational impact force about the axis, and to apply the rotational impact force to the anvil. The anvil includes a base portion (), an end bit attachment portion (), and a connecting portion (). The base portion is rotatably supported by the housing. An end bit is attachable to the end bit attachment portion. The end bit attachment portion has a flat surface portion. The connecting portion integrally connects together the base portion and the end bit attachment portion. The connecting portion has a diameter gradually reduced in a direction from the base portion toward the end bit attachment portion. The connecting portion is formed with a recessed portion (A,B,). The connecting portion has an outer peripheral surface portion where the recessed portion is formed. The recessed portion is recessed, in an axial direction from the end bit attachment portion toward the base portion, from a point where the recessed portion is connected to the outer peripheral surface portion in a cross-section taken along a plane parallel to the flat surface portion and passing through the recessed portion.

Power tool

Provided is a rotary tool with a compact tip tool holding portion (). The rotary tool is provided with a sleeve () attached to an output shaft () to switch a tip tool () between a fixed state and a detachable state. The output shaft () has a through hole () formed therein radially penetrating from the inside to the outside of a mounting hole thereof. The through hole () has a steel ball () provided therein such that at least a part of the steel ball () overlaps at least a part of a case (). The sleeve () defines a first position in the outward direction of the steel ball (), while the case () regulates a second position on the radially outer side of the first position.

Rotary tool

Provided is an electric device capable of suppressing vibration of a battery pack. Included are: a first housingaccommodating a load portion that consumes electric power; a second housinghaving one end portion connected to the first housingand another end portion to which a battery packis connectable; and an elastic memberinterposed between the first housing and the second housing. The first housing includes a first restricting portionpositioned away from the elastic member, and the second housing includes a second restricting portionpositioned away from the elastic member and engageable with the first restricting portion. In a case where the second housing is urged to be separated from the first housing, the elastic member is deformed and the first restricting portion and the second restricting portion are engaged with each other to prevent separation.

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Hitachinaka, Japan

Kengo Tamura