GB1215368A - Siphon valve - Google Patents

Abstract

1,215,368. Siphonic cisterns. AQUAIR CORP. Ltd. 19 April, 1968, No. 18743/68. Heading E1C. A "self-correcting" siphon valve for a cistern comprises primary, 22, secondary, 24, and tertiary, 26, siphons with a primary air opening 58 in the primary siphon which can be connected to atmosphere to initiate a flush, by releasing air compressed in the primary siphon, a secondary air inlet 66 to break the siphon, and a delay device to prevent air entering the inlet 66 until the water level in the cistern has dropped some way below the level of the inlet 66. This device may 'be a reservoir 70 between the primary and secondary siphons with a small outlet 74, the level in reservoir 70 falling slower than in the cistern. Alternatively, (Fig. 16, not shown) an air inlet duct is routed through a valve connected to the air release button 64, which has a time delay device associated therewith to delay opening of said valve until a predetermined time after the flush has begun. The position of the bottom of the tertiary siphon 26 causes a water trap to be formed at 42. The valve is moulded from a plastics material, and a de-odourising device (Figs. 17, 18, not shown) may be attached to the secondary siphon, with one or two waterspraying devices employed .to suck air from the outlet leg of the secondary siphon. The inlet to the tertiary siphon may be stepped into the wall of the secondary siphon to reduce flow into the tertiary siphon (Fig. 14, not shown), or a deflector 43 may be used.