SPRING-DRIVEN PUMP FOR DISPENSING DISCRETE BURSTS OF LIQUID

摘要

An oral care device (10) with a pump assembly (12) comprising: a plunger assembly (52) comprising a rack assembly (74); a compressible spring (64) configured to exert a forward force on the plunger assembly; and a rack and pinion assembly (72) configured to exert a force on the plunger assembly opposite the forward force, wherein the rack assembly comprises a plurality of rack teeth (74a...74g) and the pinion assembly (76) comprises a plurality of teeth (78) arranged around a portion of the pinion; wherein the plurality of rack teeth comprise an angled front surface (86) and an angled rear surface (87), the front surface of at least some of the plurality of rack teeth comprising a different angle than the rear surface, and further wherein at least some of the plurality of rack teeth comprise a pointed or rounded tip (82).