Filter with change indicator
US8021618B1 · kind B1 · utility
18Cited by
20References
12Claims
0Family size
Inventor
Key dates
| Filing date | Sep 19, 2006 |
| Grant date | Sep 20, 2011 |
| Priority date | — |
| Expiry date | Jun 11, 2030 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D46/0086
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A filter change indicator is provided and includes a fragrance and auditory emission apparatus adapted to be installed in disposable-type air filters utilized to remove contaminants carried along in the air stream of HVAC systems. The fragrance and auditory emission apparatus functions to emit a shrill tone or whistling noise when the air filter becomes dirty or clogged. The fragrance and auditory emission apparatus also functions as an air freshener or a room deodorizer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.