Makita Electric Works, Ltd.

Makita Corporation

Takashi Yamazaki

Fusao Fushiya

Mikio Saito

Katsumi Tozawa

Mitsuyoshi Shibata

Yoshio Sugiyama

Katsuyasu Ito

Zenichi Oda

Matsuo Ohashi

A lock washer (,) presses balls (,) and pins (,) against a clutch cam (,) with protrusions (,) formed on its front face. A rear end (,) of a spring holder (,) abuts on the inner edge of the front face of the lock washer (,) while the half of the front end surface of each pin (,) abuts on the rear face of the outer edge of the lock washer (,). Furthermore, the compression spring (,) also abuts on the lock washer (,) with its outer edge approximately aligned with the outer edge of the lock washer (,). Therefore, if a large load is instantaneously applied to a spindle (,) at the end of screw tightening, the outer edge of the lock washer (,) deforms forward. This in turn causes the balls (,) to ride over the protrusions (,) of the clutch face, thus allowing a slight rotation of the internal gear (,). This clutch operation lessens the impact that occurs at the end of screw tightening, serving to protect the tool mechanism and to reduce the shock to the operator's hand.

Clutch mechanism for use in a power-driven tool

An impact tool includes a body, a barrel mounted on the body and a cylinder disposed within the barrel and reciprocally moved by a drive mechanism. A communication groove is formed between the cylinder and the barrel and communicates with the outside. The cylinder includes a plurality of communication holes formed in a radial direction and spaced from each other in a longitudinal direction. A striker is reciprocally movable within the cylinder, and an air chamber is formed between the striker and the cylinder. The striker is positioned at a first position when the tool bit is not pressed on a work. The striker at the first position permits communication between the air chamber and the communication groove through any one of the communication holes so as to be prevented from idle impact. Further, the striker is movable to a second position rearward of the first position through the pressing operation of the tool bit on the work. The striker at a position rearwardly of the second position prevents communication between the air chamber and the communication groove so as to permit normal impact operation by the tool bit.

Impact tool

Portable electric hammer drill

A portable reciprocating saw includes a tool housing, an electric motor enclosed in the tool housing and having an output shaft, an elongated slider for supporting a saw blade, and motion converting means mounted in the tool housing for converting the rotation from the electric motor into a reciprocating motion of the slider in longitudinal direction. The motion converting means includes a bevel gear meshing with the ouptut shaft of the electric motor and rotatable about an axis inclined to a plane transverse to the longitudinal direction of the slider, a slider block mounted on the slider and having a guide groove formed on a lower surface thereof in a direction transverse to the longitudinal direction of the slider, and an eccentric pin mounted on the bevel gear at a position eccentric from the center of the bevel gear and loosely fitted in the guide groove of the slider block. With this arrangement, during operation of the electric motor, the slider performs a composite orbital motion including a reciprocating motion in longitudinal direction and a pivotal motion about a pivot axis extending transverse to the longitudinal direction.

Portable reciprocating saw

Lawn mower

A portable, cordless battery-powered tool with a relatively small overall length is provided. A handle section forms the rearmost part of the tool. An electric motor is located below a spindle and forwardly of the handle section. The motor has a rotatable shaft located in parallel with the spindle. The handle section is provided with a switch trigger which is substantially aligned with the central axis of the spindle at its top.

Portable battery-powered tool

Growing community of inventors

Anjo, Japan

Takashi Yamazaki