Makita Corporation

Fuji Electric Co., Ltd.

Okada Electric Co, Ltd.

Toshio Matsumoto

Hideki Watanabe

Akihito Hara

Tatsuki Mori

Masahiko Sako

Kazuma Oshima

Masatoshi Sugiura

Takahide Kawakami

Toshiyasu Kasuya

Masami Furuta

Takanori Kanou

Takao Iwatsuki

Hideiki Niwa

Hideki Watanable

A lighting device includes a mount adapted to be attached to a power tool. A flexible support extends from the mount and permits the lighting device to be oriented in any desired direction. A fluorescent lamp is mounted on the flexible support opposite to the mount. An electric circuit serves to light the fluorescent lamp and includes an inverter circuit.

Lighting devices for power tools

The cord guard 1 having a cylindrical hollow passage 5 into which a cord 3 can be inserted and a flange portion 11 at one end which is retained by a cord guard retainer 9 in a half housing 7. The cord guard 1 further having a tapering wall portion 13 the wall thickness of which is gradually reduced from the flange portion 11 toward the free end, a constant wall portion 15 extending in series from the tapering wall portion 13 further toward the free end with its wall thickness constant, and a thicker wall ring flange 17 provided along the periphery of the free end of the constant wall portion 15. The wall thickness and the length of the constant wall portion 15 are determined such that the constant wall portion 15 is provided with a bending strength low enough that it is flexed smoothly together with the cord 3 when a load approximately equal to the weight of the cord 3 is applied as a bending load.

Cord guard

A battery charging system is disclosed for charging two different types of battery packs, a known three terminal type including batteries and a thermostat switch, and a newer four terminal type further including a thermistor for sensing battery temperature. A charging control circuit stops charging current to the battery pack when a contact of the thermostat switch is open or when the thermistor detects a temperature above a predetermined temperature. If either the thermostat switch or the thermistor fail to properly operate, charging current to the battery pack is stopped securely to avoid damaging batteries.

Battery charger detecting full charge of batteries using a thermostat

A battery charger includes a circuit for detecting battery voltage (V1) appeared when a predetermined time (T1) has elapsed after starting a charging operation. The determination as to whether the battery has been fully charged is performed after the battery voltage has reached the sum of a predetermined potential difference (dVS) and the battery voltage (V1).

Battery charger which accounts for initial surge in battery voltage and

A battery charger includes a circuit for monitoring a battery voltage during supply of a charging current to a battery, and a circuit for stopping the supply of the charging current when the battery voltage is decreased by a predetermined value after the battery voltage has reached its maximum value. A first predetermined value is adopted as the predetermined value when an increasing tendency of the battery voltage is detected after a predetermined time has elapsed from starting of the charging operation. A second predetermined value is adopted as the predetermined value until the increase tendency of the battery voltage is monitored after the predetermined time has elapsed from starting of the charging operation. The absolute value of the first predetermined value is determined to be smaller than that of the second predetermined value. The predetermined time is determined to be longer than the period of duration of temporary abrupt variation in the battery voltage which may be produced at the beginning of the charging operation of the over-discharged battery.

Battery charger with improved change stopping capability

A battery charger includes a transformer having a primary coil and a secondary coil, a switch for duty control of a current flowing through the primary coil of the transformer, a detector for detecting a value of a current flowing through the secondary coil of the transformer, and a secondary controller for receiving the detected value from the detector and for outputting a charge control signal. The pulse of the charge control signal is modulated in accordance with the detected value by the detector. The battery charger further includes a light emitter controlled by the charge control signal for flickering, a phototransistor turning on and off according to the flickering of the light emitter, and a primary controller for converting the ratio of the time during on of the phototransistor to the time during off of the phototransistor into an analog value, and for outputting to the switch a pulse signal which is modulated to have a duty cycle corresponding to the analog value so as to control a duty cycle of the switch.

Growing community of inventors

Anjo, Japan

Toshio Matsumoto