| 摘要 |
The drain plunger preferably is of one-piece preferably plastic construction, with an upstanding, preferably vertical, rigid upper handle, the lower end of which is connected integrally to a depending multi-pleated, flexible, resilient bellows having an elastic memory. The bellows includes a small diameter upper end and downwardly diverging, frusto-conical sidewalls, the latter incorporating generally horizontally extending generally vertically stacked pleats and an open lower end terminating in a sealing rim of greater diameter than the top of the bellows. The bellows defines a central space. The rim is generally planar and preferably cyclindrical, curving in its relaxed state downwardly and inwardly from its outer margin to its inner margin, the latter curving upwarding during compression of the bellows against a surface and curving downwardly during urging upwardly of the handle after compression of the bellows rim against a surface to increase the sealing force of the plunger and its suction relative to that surface. Preferably, the pleats exhibit progressively increasing flexibility from the top to the bottom pleat and rim. The handle of the plunger can be formed of high density polyethylene plastic and the bellows can be formed of progressively varying proportion of low density polyethylene plastic and ethylene-vinyl acetate copolymer.
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