Nohmi Bosai Ltd.

Eiji Hirooka

Mikio Mochizuki

Makoto Yasukawa

Keiichi Takahashi

Nobuyuki Ichikawa

Kenji Takeyoshi

Yasuo Ariga

A fire alarming system includes a plurality of terminal devices including fire sensors, transmitters, manual boxes, and/or other devices to be controlled; and a receiving device to which the plurality of terminal devices are connected. A great number of terminal devices with a manual box are connected to the receiving device. When a plurality of manual boxes are activated at the same time, the terminal devices corresponding to the activated manual boxes can be called at the same time without encountering a collision among returning-back signals transmitted from these terminal devices. That is, when a plurality of manual boxes are activated at the same time, the signal of only one of the plurality of activated manual boxes can arrive at the receiving device.

Fire alarming system

A fire alarming system includes a plurality of terminal devices including fire sensors, transmitters, manual boxs, and/or other devices to be controlled; and a receiving device to which the plurality of terminal devices are connected. A great number of terminal devices with a manual box are connected to the receiving device. When a plurality of manual boxs are activated at the same time, the terminal devices corresponding to the activated manual boxs can be called at the same time without encountering a collision among returning-back signals transmitted from these terminal devices. That is, when a plurality of manual boxs are activated at the same time, the signal of only one of the plurality of activated manual boxs can arrive at the receiving device.

A fire detector capable of readily and accurately adjusting the sensitivity there of and of not erroneously outputting any fire signal is provided with a first-stage amplifying circuit having an output adjusting variable resistor and a fire discriminating section having a reference voltage adjusting variable resistor. As a result, it is possible to adjust the amplified output to a predetermined value by the switching level of the fire discriminating section to a predetermined value by the reference voltage adjusting variable resistor.

Fire detector

A fire detector capable of readily and accurately adjusting the sensitivity thereof and of not erroneously outputting any fire signal is provided with a first-stage amplifying circuit having an output adjusting variable resistor and a fire discriminating section having a reference voltage adjusting variable resistor. As a result, it is possible to adjust the amplified output to a predetermined value by the switching level of the fire discriminating section to a predetermined value by the reference voltage adjusting variable resistor.

A photoelectric type fire detector has: a detector body; a printed circuit board disposed on the upper side of the detector body; conductive connecting members provided on the lower side of the detector body; terminal screws for simultaneously fixing the printed circuit board and the conductive connecting members to the detector body; an optic base directly placed on the upper side of the printed circuit board and having a labyrinth formed on the upper side thereof; hooks for fixing the optic base to the upper side of the printed circuit board; a light-emitting element and a light-receiving element arranged in a pair for detecting smoke; a bug screen provided on the outer periphery of the labyrinth of the optic base; an optic base cover covering the upper side of the optic base; and a protective cover covering the printed circuit board, the optic base, the bug screen and the optic base cover. The protective cover has a plurality of smoke inlet windows and is provided with hooks on the lower end thereof, the hooks engaging the detector body to fix the protective cover to the upper side of the detector body. The invention is also applicable to a heat-photoelectric type fire detector in which a heat sensing element connected to the printed circuit board is combined with the photoelectric fire detecting function. The heat sensing element is securely fixed by a protective cover of the device.

Growing community of inventors

Tokyo, Japan

Eiji Hirooka