| 摘要 |
<p>An electrically operable liquid soap dispenser responsive to the presence of a user dispenses a measured amount of soap on demand. It has a spout (10) with a fluid conduit (36) therein connecting a soap reservoir (54) and a nozzle (38, 184). A pump (14) draws soap from the reservoir during an upstroke of its plunger (88) and depending on the embodiment, ejects a measured amount of soap during a subsequent plunger downstroke or upstroke. At least one check valve (74, 92, 226) regulates the flow of soap from the reservoir to an orifice (52) at the nozzle. The soap path from the reservoir to the nozzle is kept full of soap so that a single cycle of the pump is sufficient to eject the desired amount of soap. The orifice is sized and shaped so as to prevent dripping while maintaining soap at the nozzle ready to be ejected. A light beam emitter (30, 172) and detector (32, 176) control operation of the pump.</p> |
