Patent attributes
An oral care appliance (10) having a pump assembly (14) for delivering discrete bursts or shots of liquid. The pump assembly includes a pump housing (36) and an inlet/outlet assembly (38) at a forward end of the housing, including one-way valves (80, 82) in the inlet and outlet openings. A plunger sleeve (44) is positioned within the housing with a central opening (48) in a fluid-tight relationship with the inlet and outlet assembly. A plunger (52) includes a center portion (56), positioned in the central opening of the plunger sleeve in a fluid-tight relationship therewith. The plunger sleeve includes an outer member (54) between the plunger sleeve and the internal surface of the housing. A compressible spring (64) is positioned between a forward end of the outer member of the plunger and the rear end of the housing. A drive mechanism (72) moves the plunger rearwardly, resulting in the plunger sleeve filling with liquid by vacuum action from a reservoir (26) in the appliance, and then releases the plunger, allowing the spring to move the plunger quickly forward, forcing liquid in the plunger sleeve out through the fluid outlet in a direct burst.
