| 摘要 |
The application discloses dispenser pumps, preferably of the moveable-nozzle type, with means for sealing a vent path in the extended position of the pump plunger (2). The pump body (1) includes an internal collar (86) formed at the lower end of a tubular insert (8), through which the vent path passes. This collar has an annular seal portion (9). The plunger (2) has a complementary seal portion (4) which makes a guided and fitting engagement with the pump body collar seal portion (9) when the plunger (2) reaches its extended position relative to the body (1). One or both of the plunger seal portion (4) and the body collar seal portion (9) is formed as an annular taper, so that the seal portions are guided reliably into close engagement with one another without fine manufacturing tolerances being required. Plunger lock-down formations (27,85) may be formed to engage at the bottom of the body insert (8) as mentioned, so that they remain below the top opening of the body and the latter can be provided with a seal (16) at its top opening to act against the plunger stem (22) and keep the interior of the pump mechanism clean. |
