摘要 |
A liquid dispensing device for use in the flush cistern of a water closet comprises a reservoir (13) for the liquid formulation which is fed from an inverted container (5) maintaining a constant liquid level (47) in the reservoir (13) at the mouth (37) of the container. A displacement body in the form of a piston (9), which may be magnetic, moves in a bore (56) to dispense liquid through opening (25). The piston (9) is moved by a float (11) which moves up and down as the level of water L in the cistern rises and falls on flushing. The float is coupled to the piston (9) magnetically. In another embodiment a direct mechanical coupling is used. Liquid seeps past piston (9) when in the lowered position, and is raised to overflow outlet (25) when the cistern fills. In another embodiment, liquid is dispensed on a downward stroke of the piston. The fit of piston (9) in the bore allows liquid to seep slowly past the piston to replenish the bore. |