Tamper deterring unlocking restricter for down locking pump dispensers
US4538748A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 1983 |
| Grant date | Sep 3, 1985 |
| Priority date | — |
| Expiry date | Feb 16, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05B11/106
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The plunger of the pump has a radially extending lug near its upper end which can be inserted down into a notch in the stationary pump collar when the plunger is fully depressed, so that when the plunger is then rotated in a clockwise direction relative to the collar, the lug is brought under an overhanging ledge on the collar to releasably lock the plunger in its fully depressed position. In order to deter unlocking, the lug of the plunger and the interior wall of the collar are provided with mutually interengageable structures that permit the lug to be rotated substantially without significant resistance into a final or fully locked up position against a shoulder beneath the ledge but to be held in such fully locked up position against unlocking movement unless substantial, counterclockwise-directed force is applied. Interengaging ramp surfaces on the collar and the lug slide against one another during movement of the lug into its locked up position, while abrupt, blocking surfaces thereafter oppose one another to prevent unlocking rotation unless significant force is applied to override the blocking action. The underside of the retaining ledge of the collar is also provided with…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.