Hochiki Corporation

Hiroshi Sawa

Yukio Yamauchi

Naoki Kosugi

Hiroyuki Kitta

Shinichi Aizawa

Hironobu Kawai

A thin-type photoelectric smoke detector which is less susceptible to the effect of disturbance light noise, contamination of a smoke detecting unit, etc., and which ensures high sensitivity for the optical detection characteristic of the smoke detecting section. In the photoelectric smoke detector of the type in which infrared light is irradiated into a flat smoke detecting chamber and the scattered light of the irradiated infrared light due to smoke entering into the smoke detecting chamber is detected by a light-sensing element, there are provided optical members for expanding the visual field of the light-sensing element to a flat visual field corresponding to the cross-sectional shape of the smoke detecting chamber.

Photoelectric smoke detector with expanded visual field

A temperature detecting device having rapid temperature sensing characteristics and with a fully protected temperature sensitive element. A transistor pellet potted in a resin casing having at least one thin wall is mounted in a metal protective tube in thermal contact provided through a small amount of filler material of high thermal conductivity. A heat collector is disposed around the protective metal tube in close thermal contact therewith. The edges of the heat collector are held in position against ribs formed on an insulating casing by engaging members of a protective ring which fit into corresponding notches formed in the upper portion of the ribs. Protrusions formed on the protective member prevent its rotation and removal hence making the device essentially tamperproof.

Temperature detecting device

A fire detector comprising a socket and a detector head with an electric circuit therein. The socket is provided with couplings for voluntarily defining the structure of an engaging portion thereof to designate a detector head to be coupled and each engaging portion of the detector heads have a specific structure to engage with the engaging portion defined by the couplings. Hence, no detector head other than the designated detector head can be coupled to the socket plate.

Growing community of inventors

Yokohama, Japan

Hiroshi Sawa