Protective breathing mask with compressed air supply for breathing
US3935861A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 1, 1974 |
| Grant date | Feb 3, 1976 |
| Priority date | — |
| Expiry date | Jul 1, 1994 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA62B18/02
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A protective breathing mask comprises a face encircling mask body which is connected to a compressed gas line for the supply of compressed gas thereto. The mask includes an encircling rim portion which defines an air seal cavity and it is provided with a passage in the body or separated from the body which is connected to the compressed gas line for supplying gas into the seal cavity. The rim includes an inner lip which engages over the face of the wearer and the gas which is circulated to the cavity escapes between the lip and the face into the mask interior. The gas conduit advantageously includes a lung demand inlet valve which opens into the front or into one side of the mask and which has a by pass passage through a throttle to the seal cavity. The seal cavity is advantageously defined by an outwardly formed annular bead or by an annular tubular member which may for example have openings around its periphery for directing the compressed gas from the cavity into the mask interior.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.