Pump dispenser for fluent products featuring a reciprocable plunger and diaphragm seal

摘要

A pump dispenser for fluent products is disclosed as inluding a container for housing the fluent product, dispensing outlet means on the container, a follower piston closing the lower end of the container below the product, and means for varying the volume within such dispenser. The volume varying means comprises a plunger adapted to be reciprocated within the dispenser to alternately decrease the volume therewithin and, following such decrease, return to its original position thereby increasing the volume within the dispenser. The plunger further comprises a peripheral skirt having predetermined outer lateral dimensions at its lower distal end, and an enlarged attachment head on such lower distal end. The attachment head has predetermined outer lateral dimensions which are larger than the outer lateral dimensions of such lower distal end therey effectively forming a reentrant portion on the plunger above the enlarged head. A flexible thin-walled diaphragm adapted to isolate and seal the volume reducing means from the fluent product is connected about its outer periphery to the dispenser. The diaphragm further has a central portion substantially conforming to the enlarged attachment head and reentrant portion of the plunger thereby effectively locking the diaphragm to the plunger and its attachment head. The attached diaphragm is thereby adapted to provide a substantially frictionless seal between the reciprocable plunger and the fluent product. The unique structure and combination of the plunger and flexible diaphragm of the subject pump dispenser provides for ease of manufacturing and handling of such pump dispenser subassembly.