US Patent 7096517 Flushing device for a lavatory

A flushing device includes a cistern, in which at least one pressure chamber is arranged with a supply line for water and a discharge valve. At least part of the flushing water may be pressurised in the pressure chamber and may be discharged for flushing through the discharge valve. At least one pressure cylinder unit is provided, in which the flushing water may be pressurised and discharged for flushing, by means of a spring-loaded pressure piston. The pressure piston is preferably held in a starting position and may be released for a flushing execution. Should two pressure cylinder units be provided, either a partial or a complete flushing operation may be selected.