US6375725B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
End-of-service indicator including porous waveguide for respirator cartridge
Assignee: INSTUTE DE RECHERCHE EN SANTE ET SECURITE DU TRAVAIL DU QUEBEC
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Filing: 1999-03-26
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Granted: 2002-04-23
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Expires: 2019-03-26
Abstract
Abstract An end-of-service indicator for use with a respirator cartridge, the end-of-service indicator having an optical waveguide having two extremities, one of the extremities being connected to a light source, the other of the extremities being connected to a detector which measures the intensity of light guided and transmitted by the fiber. An alarm is connected to the detector and is triggered when the intensity of light measured by the detector is below a predetermined level. An important aspect of the end-of-service indicator is that at least a portion of the optical fiber is porous. In use, the end-of-service indicator is placed inside a respirator cartridge having a gas/vapor sorbent, so that when the respirator cartridge is used in a toxic environment, the gas/vapor sorbent and the porous glass gradually become saturated. This porous glass will absorb the gas/vapor in the same fashion as the sorbent used in the respirator cartridge, thereby lowering the guiding and transmission properties of the optical fiber which loses the necessary conditions to guide light.
Inventors
- 👤 Pierre Bernard
- 👤 Serge Caron
- 👤 Marco St-Pierre
- 👤 Jaime Lara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:36
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/75; G01N21/77; G01N21/7703; G01N2021/7706; G01N2021/7726; G01N2021/7769; G01N2021/7776; Y; Y10; Y10S; Y10S55/00; Y10S55/34
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
127 words
An end-of-service indicator for a respirator cartridge having a gas/vapor sorbent, said end-of-service indicator comprising: a waveguide having two extremities, one of said extremities being connected to a light source, the other of said extremities being connected to a detector, said detector measuring the intensity of light transmitted by said waveguide; and an alarm operatively connected to said detector, said alarm being triggered when the intensity of light measured by said detector is below a predetermined level; wherein at least a portion of said waveguide contains holes; whereby, in use, when said end-of-service indicator is used in a toxic environment, said portion of said waveguide that contains holes gradually becomes saturated through adsorption, thereby lowering the guiding and transmission properties of said waveguide and triggering the alarm.
Claim 2
Dependent Claim
127 words
An end-of-service indicator for a respirator cartridge having a gas/vapor sorbent, said end-of-service indicator comprising: a waveguide having two extremities, one of said extremities being connected to a light source, the other of said extremities being connected to a detector, said detector measuring the intensity of light transmitted by said waveguide; and an alarm operatively connected to said detector, said alarm being triggered when the intensity of light measured by said detector is below a predetermined level; wherein at least a portion of said waveguide contains holes; whereby, in use, when said end-of-service indicator is used in a toxic environment, said portion of said waveguide that contains holes gradually becomes saturated through adsorption, thereby lowering the guiding and transmission properties of said waveguide and triggering the alarm.
Claim 3
Dependent Claim
15 words
An end-of-service indicator according to claim 1 , wherein said waveguide is an optical fibre.
Claim 4
Dependent Claim
32 words
An end-of-service indicator according to claim 2 , wherein said fibre has a cladding and a core and said at least one portion of said waveguide that contains holes is said cladding.
Claim 5
Dependent Claim
35 words
An end-of-service indicator according to claim 2 , wherein said fibre has a cladding and a core and said at least one portion of said waveguide that contains holes has said cladding and said core.
Claim 6
Dependent Claim
17 words
An end-of-service indicator according to claim 3 , wherein said optical fibre further includes a polymer coating.
Claim 7
Dependent Claim
24 words
An end-of-service indicator according to claim 2 , wherein said at least one portion of said waveguide that contains holes has a predetermined length.
Claim 8
Dependent Claim
14 words
An end-of-service indicator according to claim 2 , wherein said optical fibre is straight.
Claim 9
Dependent Claim
18 words
An end-of-service indicator according to claim 2 , wherein at least one portion of said fibre is cork-screwed.
Claim 10
Dependent Claim
51 words
An end-of-service indicator according to claim 2 , wherein: said light source is a LED; said detector includes a light sensor, having an output which is operatively connected to an amplifier, said amplifier being operatively connected to a voltage-frequency converter; and said alarm is a visual alarm consisting of a LED.
Claim 11
Dependent Claim
14 words
An end-of-service indicator according to claim 3 , wherein said optical fibre is straight.
Claim 12
Dependent Claim
14 words
An end-of-service indicator according to claim 4 , wherein said optical fibre is straight.
Claim 13
Dependent Claim
14 words
An end-of-service indicator according to claim 5 , wherein said optical fibre is straight.
Claim 14
Dependent Claim
14 words
An end-of-service indicator according to claim 6 , wherein said optical fibre is straight.
Claim 15
Dependent Claim
16 words
An end-of-service indicator according to claim 3 , wherein a portion of said fibre is cork-screwed.
Claim 16
Dependent Claim
16 words
An end-of-service indicator according to claim 4 , wherein a portion of said fibre is cork-screwed.
Claim 17
Dependent Claim
16 words
An end-of-service indicator according to claim 5 , wherein a portion of said fibre is cork-screwed.
Claim 18
Dependent Claim
16 words
An end-of-service indicator according to claim 6 , wherein a portion of said fibre is cork-screwed.
Claim 19
Dependent Claim
51 words
An end-of-service indicator according to claim 3 , wherein: said light source is a LED; said detector includes a light sensor having an output which is operatively connected to an amplifier, said amplifier being operatively connected to a voltage-frequency converter; and said alarm is a visual alarm consisting of a LED.
Claim 20
Dependent Claim
51 words
An end-of-service indicator according to claim 4 , wherein: said light source is a LED; said detector includes a light sensor having an output which is operatively connected to an amplifier, said amplifier being operatively connected to a voltage-frequency converter; and said alarm is a visual alarm consisting of a LED.
Claim 21
Dependent Claim
51 words
An end-of-service indicator according to claim 5 , wherein: said light source is a LED; said detector includes a light sensor having an output which is operatively connected to an amplifier, said amplifier being operatively connected to a voltage-frequency converter; and said alarm is a visual alarm consisting of a LED.
Claim 22
Dependent Claim
51 words
An end-of-service indicator according to claim 6 , wherein: said light source is a LED; said detector includes a light sensor having an output which is operatively connected to an amplifier, said amplifier being operatively connected to a voltage-frequency converter; and said alarm is a visual alarm consisting of a LED.
Claim 23
Dependent Claim
18 words
An end-of-service indicator according to claim 9 , wherein said optical fibre is treated with a hydrophobic coating.
Claim 24
Dependent Claim
18 words
An end-of-service indicator according to claim 18 , wherein said optical fibre is treated with a hydrophobic coating.
Claim 25
Dependent Claim
18 words
An end-of-service indicator according to claim 19 , wherein said optical fibre is treated with a hydrophobic coating.
Claim 26
Dependent Claim
18 words
An end-of-service indicator according to claim 20 , wherein said optical fibre is treated with a hydrophobic coating.
Claim 27
Dependent Claim
18 words
An end-of-service indicator according to claim 21 , wherein said optical fibre is treated with a hydrophobic coating.
Claim 28
Dependent Claim
20 words
An end-of-service indicator according to claim 1 , wherein said holes include a plurality of interconnected micro-pores having a skeleton.
Claim 29
Dependent Claim
17 words
An end-of-service indicator according to claim 27 , wherein said skeleton is a skeleton of silica glass.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-04-22 | 2005-10-22 | 2006-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-04-22 | 2009-10-22 | 2010-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-04-22 | 2013-10-22 | 2014-04-23 | $7700.00 | Window Closed / Lapsed |