Patent US4155358A successfully refreshed from Google Patents.
US4155358A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Respirator
Assignee: 3M Co
•
Filing: 1976-12-13
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Granted: 1979-05-22
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Expires: 1996-12-13
Abstract
Abstract A disposable valveless chemical cartridge respirator for filtration of vinyl chloride monomer having an end of service life indicator is disclosed.
Inventors
- 👤 Jerome W. McAllister
- 👤 James A. Ord, Jr.
- 👤 Leon W. Anders
- 👤 Gunter A. Kohler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:02
CPC Classifications
A; A62; A62B; A62B18/00; A62B18/08; A62B18/088; Y; Y10; Y10T; Y10T436/00; Y10T436/19; Y10T436/196666
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
168 words
A disposable valveless chemical cartridge respirator for filtration of vinyl chloride monomer comprising a body including a facepiece having means for peripherally sealing contact with at least that portion of a human head which includes the nose and mouth, associated fastening means for holding said respirator in position on the head, a cartridge on said body having an air entrance and an air exit communicating with the interior of said respirator and containing therewithin filter media comprising activated carbon and an end of service life indicator said cartridge having a volume of about 220 cc. for said indicator and said filter media, said indicator being disposed across the path of air intake at the entrance of said cartridge, said filter media and indicator being adapted for adsorption thereon of a vinyl chloride monomer contaminant upon inhalation therethrough, said indicator including means upon exposure to a predetermined amount of vinyl chloride monomer undergoing a dramatic and distinct color change to indicate the end of service life of said respirator.
Claim 2
Dependent Claim
168 words
A disposable valveless chemical cartridge respirator for filtration of vinyl chloride monomer comprising a body including a facepiece having means for peripherally sealing contact with at least that portion of a human head which includes the nose and mouth, associated fastening means for holding said respirator in position on the head, a cartridge on said body having an air entrance and an air exit communicating with the interior of said respirator and containing therewithin filter media comprising activated carbon and an end of service life indicator said cartridge having a volume of about 220 cc. for said indicator and said filter media, said indicator being disposed across the path of air intake at the entrance of said cartridge, said filter media and indicator being adapted for adsorption thereon of a vinyl chloride monomer contaminant upon inhalation therethrough, said indicator including means upon exposure to a predetermined amount of vinyl chloride monomer undergoing a dramatic and distinct color change to indicate the end of service life of said respirator.
Claim 3
Dependent Claim
39 words
A disposable valveless chemical cartridge respirator according to claim 1 wherein said indicator comprises activated alumina granules in a size range of 8 to 14 mesh coated with potassium permanganate, said color change being from pink to light cream.
Claim 4
Dependent Claim
79 words
A disposable valveless chemical cartridge respirator according to claim 1 wherein said indicator comprises activated alumina granules having a first color enhancing coat of manganese dioxide overcoated with a second color coat of potassium permanganate, said color coat of said indicator upon exposure to a predetermined amount of vinyl chloride monomer being reduced to manganese dioxide such that there is a slow, continuous color change from purple to brown to indicate the end of service life of said respirator.
Claim 5
Dependent Claim
30 words
A disposable valveless chemical cartridge respirator according to claim 3 wherein said filter media and indicator are contained in a cartridge integrally formed as a part of the respirator body.
Claim 6
Dependent Claim
71 words
A disposable valveless chemical cartridge respirator according to claim 4 containing about 190 cc. of activated carbon and about 30 cc. of indicator granules, said respirator upon exposure to an atmosphere containing 10 parts per million of vinyl chloride gas having a breakthrough time to one part per million of vinyl chloride gas of about 295 minutes and an end of service life indicator color change time of about 256 minutes.
Claim 7
Dependent Claim
26 words
A disposable valveless chemical cartridge respirator according to claim 4 wherein said indicator granules are disposed in a layer located at the entrance of said cartridge.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-21 | 1982-11-20 | 1983-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-21 | 1986-11-20 | 1987-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-21 | 1990-11-20 | 1991-05-22 | $7700.00 | Window Closed / Lapsed |