Air filters
US4268290A · kind A · utility
51Cited by
3References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 31, 1979 |
| Grant date | May 19, 1981 |
| Priority date | — |
| Expiry date | May 31, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2279/60
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A pleated paper filter element has the configuration of the frustrum of a cone with the pleats extending lengthwise of the sloping wall of the cone and has pleat separation dimples embossed into the paper from which the element is made, the height of said dimples being graduated lengthwise of the element so as to provide controlled pleat separation over at least most of the length of the element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.