Hitachi Koki Co., Ltd.

Takahiko Shimada

Chikai Yoshimizu

Hiroaki Orikasa

Kazuhiko Funabashi

Atsushi Nakagawa

Eiji Nakayama

Shigeru Shinohara

Kazumi Takeishi

Siyouiti Sakamoto

Masao Kikumoto

A reciprocal-movement power tool includes a movable blade reciprocally movably provided on a main body. A receiving plate that supports an angle iron to be cut is supported on the main body at a position in front of the movable blade. The movable blade is fixed on a front tip of a rod-shaped shuttle screw. The shuttle screw moves back and forth in the axial direction within a tubular screw shaft. The screw shaft is carved with a female screw portion and is rotated through a joint spindle that is deceleratingly rotated upon rotation of the motor through a deceleration means. The shuttle screw has a male screw portion that is threadingly engageable with the female screw portion.

Reciprocal-movement power tool

A DC power source unit includes a main unit that generates DC voltage, and an output cable. The output cable is connected, either integrally or detachably, at one end to the output of the main unit and another end to an adapter plug. The adapter plug is electrically connected to an electrically powered tool, such as an electrical drill. An output voltage switching unit switches the level of voltage supplied by the main unit to the electrically powered tool, to a level that matches the rated voltage of the electrically powered tool that corresponds to the fitting portion of the adapter plug.

DC power source unit

A DC power source unit includes a main unit that generates DC voltage, and an output cable. The output cable has one end connected to the output of the main unit and another end attached to an adapter plug. The adapter plug Is electrically connected to an electrically powered tool, such as an electrical drill. Current flowing in the tool is detected every predetermined interval and accumulated electrical quantity is computed based on the detected current flowing in the tool. Based on the accumulated electrical quantity, the temperature of the tool is predicted. When it is determined that the tool is heated up to a first critical temperature based on the accumulated electrical quantity, an alarm unit is actuated. When it is determined that the tool is further heated up to a second critical temperature, supply of current to the tool is interrupted.

DC power source unit alarming before electrically powered tool is overheated and stopping power supply thereafter

A motor is housed in a main body and a transmission gear of a series of three transmission gears is mounted to a motor shaft. The last of the series of transmission gears is mounted on one end of an elongated and distortable connection rod. A first bevel gear is attached to the other end of the connection rod. A second bevel gear, which in engagement with the first bevel gear, is attached to one end of a spindle. The spindle extends in a direction perpendicular to the direction in which the connection rod extends. A wheel shaped bit is attached to the other end of the spindle. Rotation of the motor is transmitted to the bit via the three transmission gears, the connection rod, the two bevel gears, and the spindle. To cut a workpiece, the rotating bit is repeatedly moved back and forth into the surface of the workpiece. A handle is attached to the main body and extends in a plane which contains an axis of the motor shaft. A secondary handle with a grip is attached to the main body so that the grip is positioned to intersect the plane.

Electric-powered stone cutter

A saber saw assembly includes a vice for clamping an object to be cut and a saber saw having a saw blade to be operated in reciprocating motion. The saber saw is arranged to cut the object with the reciprocating saw blade while the object is clamped by the vice. The vice is in the form of a pipe wrench. The pipe wrench clamps the object when rotated in a clamping direction while releases the object when rotated in a releasing direction opposite to the clamping direction. Accordingly, by using the pipe wrench for the vice, the clamping and releasing operations for the object are simplified to enhance the working efficiency for cutting the object.

Growing community of inventors

Hitachinaka, Japan

Takahiko Shimada