Dual flush cistern mechanism

Claim 1

A dual flush cistern mechanism comprising a substantially vertical stem mounted for substantially vertical movement above a flush valve of said cistern and having a flush valve seal located at its lower end; a float slidably mounted on said stem intermediate the ends thereof; a first lever arm pivotably connected to said stem at a location spaced from a first pivot in said cistern for said first lever arm, and being pivotable by each of a first and a second operating mechanism to raise said stem to open said flush valve; a second lever arm pivotable by said second operating mechanism about a second pivot in said cistern and carrying a latch member releasably engageable with said float in a high operating position, and a projection extending from said stem to limit the travel of said float into a low operating position; wherein said first operating mechanism is operable to raise said stem with said float retained in said high operating position by said latch member to open said flush valve for a first duration; and wherein said second operating mechanism is operable to substantially simultaneously raise said stem to open said flush valve to drain water from said cistern and release said latch member whereby said float drops with the water level in said cistern until said float engages said stem projection to move said stem downwardly and close said flush valve before the expiration of said first duration, said float being buoyantly movable from said low to said high position to re-engage said latch member with said float when said cistern is re-filled with water, and said first and second pivots each having a longitudinal axis which is stationary with respect to said cistern.