| 摘要 |
The actuating lever of the dispenser has a rigid valve flap integral therewith which covers the spout outlet to close the same when the actuating lever is in its normal, undepressed position but which then lifts off the outlet to open the same when the lever is depressed in a pumping stroke. One embodiment employs a reciprocable pumping piston at one end of the dispenser body and a free-floating take-up piston at the opposite end of the body which responds to the evacuationof material within the pump chamber to take up the space otherwise occupied by the evacuated product. Another embodiment utilizes a pumping piston which starts at the lower end of the dispenser body and is progressively drawn up toward the opposite end during successive pumping strokes by a rod connected to the actuating lever. |
