Nozzle assembly for dispensing liquid
US5392989A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 1994 |
| Grant date | Feb 28, 1995 |
| Priority date | — |
| Expiry date | May 24, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05C5/02
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An improved nozzle assembly for dispensing liquid is disclosed. In a first embodiment of the invention, the liquid dispenser comprises a nozzle assembly with an expansive cavity at its dispensing end. When the flow of liquid in the dispenser is halted, a pocket of liquid formed inside the cavity ties the liquid in the nozzle to the liquid in a drop formed at the tip of the nozzle. Thus, when "suck-back" is applied, the drop is pulled into the cavity and up the nozzle, leaving at most a very small and stable amount of liquid inside the cavity. In a second embodiment of the invention, an inner nozzle tube extends beyond the end of an outer nozzle tube, creating an external annular recess which captures and holds a drop of liquid over the end of the nozzle. After suck-back, the drop is pulled up into the nozzle, leaving a small, stable amount of liquid in the annular recess.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.