Makita Corporation

Other

Fuji Electric Co., Ltd.

Okada Electric Co, Ltd.

Masatoshi Sugiura

Kazuyuki Sakakibara

Youichi Kato

Yutaka Matsunaga

Toshio Matsumoto

Masami Furuta

Hideki Watanabe

Kazuyoshi Horikawa

Tomoo Muramatsu

Yoshiharu Shimizu

Takao Iwatsuki

Hideiki Niwa

Masahiko Sakoh

Masahiko Sakou

A battery pack () has a double casing structure, including an inner case () disposed inside an outer case (). The inner case () includes a radiator plate () that is in contact with the side walls of battery cells () disposed within the battery pack (). A forked air passage () extends from an air inlet () and is defined between the inner case () and the outer case () and along the outer surface of the radiator plate () until reaching a pair of air outlets ().

Battery packs having improved heat radiation

A battery pack ( ) has a double casing structure, including an inner case ( ) disposed inside an outer case ( ). The inner case ( ) includes a radiator plate ( ) that is in contact with the side walls of battery cells ( ) disposed within the battery pack ( ). A forked air passage ( ) extends from an air inlet ( ) and is defined between the inner case ( ) and the outer case ( ) and along the outer surface of the radiator plate ( ) until reaching a pair of air outlets ( ).

Battery pack with improved heat radiation and sealing

A charging system includes an electric power tool (,) and a charger (,) having internal rechargeable batteries (,) and a controller (,) for monitoring the charge/discharge level of the batteries (,). The electric power tool (,) additionally includes a pair of charge terminals (,) for carrying current to charge the batteries (,), a temperature terminal (,) for outputting to the charger (,) data on the temperature of the batteries, and a data terminal (,) for outputting to the charger data on the battery charge/discharge level from the controller (,). The charger (,) includes a pair of charge terminals (,), a temperature terminal (,), and a data terminal (,) that are electrically connected to the corresponding tool terminals when the tool (,) is set on the charger for a charge. The charging system indicates the remaining charge level on an indicator unit (,) based on the received data on the battery charge/discharge level and changes the amount of the charging current based on the data on the battery charge/discharge level and the battery temperature data received from the tool (,).

Power tool charging system having a charge level indicator and charge control functions

A protection arrangement for a battery charger of the type used to charge battery packs used for electromotive tools. A self-holding protector is arranged in the neighborhood of an inserting hole of the battery charger for receiving a storage battery pack 50 to be charged. This self-holding protector element includes two elements electrically connected in parallel. One of these two elements is a bimetal which opens when it heats or flows too much current. The other of the two elements is a positive characteristic thermistor (PCT) which generates heat when a current flows through it. When a battery pack being charged becomes over-charged and heats, the bimetal element of the protector opens, and charging current stops flowing. When the bimetal element opens, electric current flows through the PCT. This current causes the PCT to heat and maintain the bimetal element in its open condition. When the battery pack being charged short-circuits, and a large current flows through it, the bimetal element opens and charging current is interrupted in the same way.

Battery charger for battery packs

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.

Battery charger with charging current controller

Growing community of inventors

Anjo, Japan

Masatoshi Sugiura