US3815592A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Closed circuit breathing apparatus
Assignee: MSA Safety Inc
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Filing: 1973-05-07
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Granted: 1974-06-11
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Expires: 1993-05-07
Abstract
Abstract A plurality of chambers containing oxygen-generating and carbon dioxide-removing chemical have outlets connected with the inhalation tube of a breathing apparatus facepiece, and inlets connected by individual conduits to separate outlets in normally closed valve means provided with an inlet connected with the exhalation tube of the facepiece. Timing means operate the valve means to first connect the exhalation tube with only one of said conduits and then at regular intervals thereafter to connect it additionally with each of the remaining conduits in succession until it is connected with all of them simultaneously, thereby periodically reducing the rising breathing resistance of the apparatus.
Inventors
- 👤 C Staub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:58
CPC Classifications
A; A62; A62B; A62B7/00; A62B7/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
139 words
Breathing apparatus comprising a facepiece, an inhalation tube and an exhalation tube connected to the facepiece, a plurality of chambers containing oxygen-generating and carbon dioxide-removing chemical and having inlets and outlets, means connecting said outlets with the inhalation tube, a separate conduit connected to each of said inlets, valve means having separate outlets connected to said conduits and having an inlet, means connecting the exhalation tube with the valve inlet, said valve means being operable to place the exhalation tube in communication with said conduits, and timing means for operating said valve means to first connect the exhalation tube with only one of said conduits and then at regular intervals thereafter to connect it additionally with each of the remaining conduits in succession until it is connected with all of them simultaneously, whereby rising breathing resistance is reduced periodically.
Claim 2
Dependent Claim
139 words
Breathing apparatus comprising a facepiece, an inhalation tube and an exhalation tube connected to the facepiece, a plurality of chambers containing oxygen-generating and carbon dioxide-removing chemical and having inlets and outlets, means connecting said outlets with the inhalation tube, a separate conduit connected to each of said inlets, valve means having separate outlets connected to said conduits and having an inlet, means connecting the exhalation tube with the valve inlet, said valve means being operable to place the exhalation tube in communication with said conduits, and timing means for operating said valve means to first connect the exhalation tube with only one of said conduits and then at regular intervals thereafter to connect it additionally with each of the remaining conduits in succession until it is connected with all of them simultaneously, whereby rising breathing resistance is reduced periodically.
Claim 3
Dependent Claim
52 words
Breathing apparatus according to claim 1, including a housing containing said chambers in a row and having a wall provided with said chamber inlets, the housing having therein an open space between another wall and said chamber outlets, and said other wall being provided with an outlet connected with said inhalation tube.
Claim 4
Dependent Claim
37 words
Breathing apparatus according to claim 1, in which said connecting means include a first breathing bag between said chamber outlets and the inhalation tube, and a second breathing bag between the exhalation tube and said valve inlet.
Claim 5
Dependent Claim
66 words
Breathing apparatus according to claim 1, including a housing containing said chambers and having a wall provided with said chamber inlets, the housing having therein an open space between another wall and said chamber outlets, and said connecting means including a first breathing bag connecting said housing wall outlet with the inhalation tube, and a second breathing bag connecting the exhalation tube with said valve inlet.
Claim 6
Dependent Claim
113 words
Breathing apparatus according to claim 1, in which said valve means includes a case provided with a cylindrical inner surface, the case having said valve inlet in one end and having said valve outlets in its side wall and spaced circumferentially thereof, a hollow cylindrical closure member rotatably mounted in said case in engagement with said surface and having an inlet in one end registering with said case inlet, the side wall of said closure member being provided with an arcuate slot positioned to register with said case outlets as the closure member is rotated in the case, and means operatively connecting said timing means to said closure member to rotate the latter.
Claim 7
Dependent Claim
62 words
Breathing apparatus according to claim 1, including a housing containing said chambers, there being two rows of said chambers spaced apart with said chamber outlets opening into the space between said rows, a wall of the housing being provided with an outlet connecting said space with the inhalation tube, and two other walls of the housing being provided with said chamber inlets.
Claim 8
Dependent Claim
44 words
Breathing apparatus according to claim 6, in which one row of chambers is disposed above the other row, and said valve means is adapted to connect the exhalation tube with the upper row of chambers before connecting it with the lower row of chambers.
Claim 9
Dependent Claim
74 words
Breathing apparatus according to claim 6, in which one row of chambers is disposed above the other row, said valve means is adapted to connect the exhalation tube with the upper row of chambers before connecting it with the lower row of chamBers, and said connecting means include a first breathing bag connecting said housing wall outlet to the inhalation tube, and a second breathing bag connecting the exhalation tube with said valve inlet.
Claim 10
Dependent Claim
23 words
Breathing apparatus according to claim 1, including beds of carbon dioxide-removing material disposed between said chemical in said chambers and said inhalation tube.
References Cited (Backward Citations)
US3390676A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |