Patent · US Expired

Water filter device

US4025438A · kind A · utility

25Cited by
10References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 10, 1975
Grant dateMay 24, 1977
Priority date
Expiry dateFeb 10, 1995

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB01D35/043
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

In accordance with the invention there is provided a water filter and water filter cartridge having an upper water filtering layer containing charcoal particles, a lower filtering layer having a submicron pore size and an intermediate filtering layer having a pore size greater than that of the lower layer but less than the particle size of the charcoal in the upper layer.

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