Hitachi, Ltd.

Fumiyasu Ookido

Setsuo Arita

Shigeru Izumi

Satoshi Suzuki

Atomi Noguchi

Fumio Murata

Shunsuke Utena

A safety control safeguard system includes sensors disposed in a quadruple array. First, second, third and fourth signal processing channels provided in parallel each include signal processing means for receiving output signals from the associated sensors for producing a trip signal. First and second actuating means operable independent of each other are provided for actuating an apparatus to be controlled. A first switch means operatively connected to the first, second, third and fourth processing channels for activating the first actuating means in response to reception of the trip signal produced by the signal processing channels and second switch means operatively connected to the first, second, third and fourth processing channels for activating the second actuating means in response to reception of the trip signal produced by the signal processing channels. The first and second switching means are operable independent of each other and constitute a 2-out-of-4 logic circuit in cooperation with the first and second actuating means.

Growing community of inventors

Hitachi, Japan

Fumiyasu Ookido