Hand-actuatable pump assembly
US4252507A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 1979 |
| Grant date | Feb 24, 1981 |
| Priority date | — |
| Expiry date | Sep 10, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05B11/1026
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An improved, hand actuatable pump assembly. A stem and piston assembly extend into a valve body. The piston sealingly engages the wall of the valve body and together they define a pressure chamber therebelow. The piston seals a discharge passageway in the stem. As the pump assembly is primed, air in the pressure chamber escapes through the discharge passageway. When the pump is ready for use, the force of hydraulic pressure below the piston opens communication between the pressure chamber and passageway. When the piston nears the end of the stroke, it is mechanically held open to complete dispensing. At all times, a positive seal between the piston and the valve body wall is maintained to prevent passage of the contents of the pressure chamber therebetween, thereby to minimize sticking and clogging of the pump assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.