Liquid dispenser with means for automatically purging air therefrom during liquid loading
US4082121A · kind A · utility
35Cited by
1References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1976 |
| Grant date | Apr 4, 1978 |
| Priority date | — |
| Expiry date | Aug 25, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01L3/0234
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A hand-held liquid dispenser of the type using a piston and piston cylinder for precise dispensing of desired volumes of liquid, including an improvement that automatically eliminates any air from the piston cylinder when an operator normally fills the piston cylinder with the desired liquid. A second piston of larger diameter than the first is disposed to draw fluid through the piston chamber at a much faster rate during a first short segment of an intake stroke than would the first piston, thereby to exhaust all dead air from the cylinder and fill it entirely with liquid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.