GB1094054A - Automatic washing apparatus for flush lavatories - Google Patents

Abstract

1, 094, 054. Automatic flushing of lavatories. TATEISI ELECTRONICS CO. May 5, 1965 [ May 12, 1964], No. 18892/65. Heading G1N. An automatic flushing apparatus for lavatories comprises capacitive detector plates 5 (Fig. 1) connected to an oscillator in a detector circuit 6 the operating condition of which changes in the presence of a user and thereby a control circuit is operated to energize an electromagnetic valve in a water supply pipe 2 when a person vacates the using position. When a user approaches the urinal bowl 1 a signal (a) (Fig. 3) is produced by the detector circuit 6 and a signal (b) from a NOT circuit transistor 7 is inverted from level 1 to level O. When a user vacates the using position signal (a) from the detector ceases and the NOT circuit commences to charge a capacitor 9 of a differentiating circuit C9, R10 and a trigger signal (c) is produced at the output of the differentiating circuit. The signal (c) is stretched to a predetermined width and amplified in an amplifier 11 the output of which energizes a relay 12 which delivers a signal (d) to open an electromagnetic valve 13 and flush the urinal bowl. The open period of the valve is dependent on the width of signal (d). If the detector signal (a) in the presence of a person is at level O instead of 1, the NOT circuit can be omitted. In an alternative embodiment Figs. 2, 4 (not shown) a time delay is introduced to permit the user to be well clear of the urinal before flushing commences.