Protective device
US5793449A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 8, 1995 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Nov 8, 2015 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F9/067
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The invention relates to a protective device of the type having a body (1) and a filtering unit (10) supported by said body and acting as a visor, said filtering unit being electrically shiftable between at least two light transmitting conditions and comprising, for this purpose, one or more LC cells. The filtering unit (10) is made wholly or at least to a major extent of polymer material and is designed as a panoramic visor which is darkenable over its entire area. Said one or more LC cells are in the form of a foil and extend over the entire area of the panoramic visor. The invention is of special interest for welding helmets with automatically controlled darkening.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.