Patent · US Expired

Positive displacement flow through fluid pump

US4139333A · kind A · utility

12Cited by
8References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 18, 1977
Grant dateFeb 13, 1979
Priority date
Expiry dateMay 18, 1997

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF04B43/0072
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

Abstract

A positive displacement flow through fluid pump especially useful for dispensing exact volumes of photoresist on a silicon wafer uses a bellows for the main pumping component. The bellows is capped at both ends and they include slugs which extend into the interior of the bellows to minimize the static volume. In addition, internal porting is provided in the slugs to effectively wash or purge the convolutions of the bellows which results in continuous cleaning.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.