Patent · US Expired

Air filters

US4498915A · kind A · utility

63Cited by
1References
3Claims
0Family size

Inventor

Key dates

Filing dateMar 12, 1980
Grant dateFeb 12, 1985
Priority date
Expiry dateMar 12, 2000

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB01D2275/201
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A generally tubular pleated paper filter element is constructed in the form of a frustrum of a cone having an aspect ratio (the ratio of element length to base diameter) in the range 1.5 to 2.5 and an included angle in the range 2 to 5 degrees.

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