US6497756B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Service life indicator for respirator cartridge
Assignee: North Safety Products LLC
•
Filing: 2000-09-12
•
Granted: 2002-12-24
•
Expires: 2020-09-12
Abstract
Abstract A rotationally adjustable respirator cartridge having a self-contained end of service life indicator adjacent the interior of a sidewall of the cartridge shell and in contact with the filter medium provides a color-changing display field that is visible to the wearer of the respirator through a transparent portion of the sidewall. A display window is defined by an opaque border area that surrounds the sensor display field and obscures a predetermined portion of the downstream end of the indicator to provide a desired margin of safety to the wearer. In order to permit the wearer to rotationally position the color-changing display field in the line of sight through the transparent portion of the respirator facepiece, the cartridge is provided with a rotatable mounting assembly that is continuously rotatable in one direction and that forms a seal with the cartridge shell.
Inventors
- 👤 Len Curado
- 👤 Edna M. deMedeiros
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:41
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01D53/0454; A; A62; A62B; A62B18/00; A62B18/08; A62B18/088; B01D53/0407; B01D53/0415; B01D2253/00; B01D2253/10; B01D2253/102; B01D2257/00; B01D2257/20; B01D2257/204; B01D2257/2045; B01D2257/2047; B01D2259/00; B01D2259/45; B01D2259/4541; B01D53/06; Y; Y10; Y10S; Y10S55/00; Y10S55/33; Y10S55/34; Y10S55/35
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
212 words
A respirator cartridge comprising: a cartridge shell having a sidewall, at least a portion of which sidewall is transparent; a chemical sensor having a color-changing display field, the sensor being securely positioned proximate an interior surface of a transparent portion of the cartridge sidewall, said display field having an upstream end and a downstream end; a display window defined by an opaque border positioned on the transparent portion of the cartridge sidewall, the display window being at least partially aligned with the display field of the sensor, the downstream end of the display field of the sensor extending to the downstream end of the display window formed by the opaque border; a chemical sorbent material contained by said cartridge shell and in touching contact with said sensor; said cartridge further comprising: an outwardly extending mounting collar joined to the cartridge shell, said mounting collar including seal-forming means, a threaded flange member having pawl and seal-forming means received in mating relation with said mounting collar, ratchet means formed in a surface of the cartridge shell to operatively engage the pawl means in the flange member, where said seal-forming means comprise an annular ring and a corresponding annular seat, whereby said flange member is securely joined to said cartridge shell in fluid-tight rotatable relation.
Claim 2
Dependent Claim
212 words
A respirator cartridge comprising: a cartridge shell having a sidewall, at least a portion of which sidewall is transparent; a chemical sensor having a color-changing display field, the sensor being securely positioned proximate an interior surface of a transparent portion of the cartridge sidewall, said display field having an upstream end and a downstream end; a display window defined by an opaque border positioned on the transparent portion of the cartridge sidewall, the display window being at least partially aligned with the display field of the sensor, the downstream end of the display field of the sensor extending to the downstream end of the display window formed by the opaque border; a chemical sorbent material contained by said cartridge shell and in touching contact with said sensor; said cartridge further comprising: an outwardly extending mounting collar joined to the cartridge shell, said mounting collar including seal-forming means, a threaded flange member having pawl and seal-forming means received in mating relation with said mounting collar, ratchet means formed in a surface of the cartridge shell to operatively engage the pawl means in the flange member, where said seal-forming means comprise an annular ring and a corresponding annular seat, whereby said flange member is securely joined to said cartridge shell in fluid-tight rotatable relation.
Claim 3
Dependent Claim
14 words
The cartridge of claim 1 where the sensor is secured in position by adhesive.
Claim 4
Dependent Claim
31 words
The cartridge of claim 1 in which the opaque border defining the display window is an elongated web of opaque material and the display window is an aperture in the web.
Claim 5
Dependent Claim
23 words
The cartridge of claim 3 in which the elongated web extends around at least a portion of the periphery of the cartridge shell.
Claim 6
Dependent Claim
15 words
The cartridge of claim 3 where the elongated web is provided with printed informational fields.
Claim 7
Dependent Claim
36 words
The cartridge of claim 3 where the color of the elongated web proximate the display window contrasts visually with the color of the color-changing field of the sensor after exposure of the sensor to a contaminant.
Claim 8
Dependent Claim
19 words
The cartridge of claim 3 where the elongated web is adhesively bonded to the exterior of the shell sidewall.
Claim 9
Dependent Claim
18 words
The cartridge of claim 1 in which the opaque area is a chemically-resistant coating on the cartridge sidewall.
Claim 10
Dependent Claim
15 words
The cartridge of claim 8 where the exterior surface of the cartridge sidewall is coated.
Claim 11
Independent Claim
168 words
A method of assembling a replaceable respirator cartridge comprising the following steps: providing a cartridge shell having an outwardly extending mounting collar and a sidewall, at least a portion of which sidewall is transparent; securely positioning a chemical sensor having a color-changing display field proximate an interior surface of a transparent portion of the cartridge sidewall, said display field having an upstream end and a downstream end; positioning a display window defined by an opaque border on the transparent portion of the cartridge sidewall, the display window being at least partially aligned with the display field of the sensor and a segment of the opaque border obscuring a portion of the downstream end of the sensor; filling the cartridge with a chemical sorbent material to contact a surface of the sensor opposite the display field; providing a mounting assembly having seal-forming means and one-way rotational means; and joining the mounting assembly to the collar, whereby said cartridge can be continuously sealingly rotated when mounted to a respirator mask.
Claim 12
Independent Claim
168 words
A method of assembling a replaceable respirator cartridge comprising the following steps: providing a cartridge shell having an outwardly extending mounting collar and a sidewall, at least a portion of which sidewall is transparent; securely positioning a chemical sensor having a color-changing display field proximate an interior surface of a transparent portion of the cartridge sidewall, said display field having an upstream end and a downstream end; positioning a display window defined by an opaque border on the transparent portion of the cartridge sidewall, the display window being at least partially aligned with the display field of the sensor and a segment of the opaque border obscuring a portion of the downstream end of the sensor; filling the cartridge with a chemical sorbent material to contact a surface of the sensor opposite the display field; providing a mounting assembly having seal-forming means and one-way rotational means; and joining the mounting assembly to the collar, whereby said cartridge can be continuously sealingly rotated when mounted to a respirator mask.
Claim 13
Dependent Claim
19 words
The method of claim 10 the chemical sensor is secured in position to the interior surface of the sidewall.
Claim 14
Dependent Claim
15 words
The method of claim 11 where the chemical sensor is secured in position by adhesive.
Claim 15
Dependent Claim
17 words
The method of claim 11 where the chemical sensor is secured in position by a mechanical fastener.
Claim 16
Dependent Claim
28 words
The method of claim 10 where the chemical sensor is formed from a plurality of superposed polymeric sheets that are sealed around their edges to form a packet.
Claim 17
Dependent Claim
20 words
The method of claim 14 where one of the exterior sidewalls of the sensor packet is gas and vapor permeable.
Claim 18
Dependent Claim
21 words
The method of claim 15 in which the permeable sidewall of the sensor packet is positioned away from the cartridge sidewall.
Claim 19
Dependent Claim
35 words
The method of claim 10 where the display window is formed in an elongated web of opaque material and the method further comprises securing the elongated web to the exterior surface of the cartridge sidewall.
Claim 20
Dependent Claim
19 words
The method of claim 17 which includes the step of adhesively bonding the elongated web to the cartridge sidewall.
Claim 21
Dependent Claim
24 words
The method of claim 17 that includes encircling the cartridge sidewall with the elongated web, whereby the sorbent material inside the cartridge is obscured.
Claim 22
Dependent Claim
20 words
The method of claim 10 where the display window is formed by applying an opaque coating to the cartridge sidewall.
Claim 23
Dependent Claim
19 words
The method of claim 20 where the opaque coating is applied to the exterior surface of the cartridge sidewall.
Claim 24
Dependent Claim
21 words
The method of claim 21 where the sensor is securely positioned proximate the cartridge sidewall after application of the opaque coating.
Claim 25
Dependent Claim
27 words
The method of claim 10 where the color of the opaque area defining the display window provides a visual contrast to the color-changing field of the sensor.
Claim 26
Dependent Claim
47 words
The method of claim 10 which includes the further steps of providing the mounting collar and the mounting assembly with elements that cooperate to form a rotatable seal and moving the elements into engagement to form a rotatable seal when the assembly is joined to the collar.
Claim 27
Dependent Claim
40 words
The method of claim 24 where the rotatable seal is formed by a projecting annular rim and a corresponding seat in the form of a resilient groove, and the seal is assembled by pressing the projecting rim into the seat.
Claim 28
Dependent Claim
56 words
The method of claim 10 where the one-way rotational means is comprised of a circular array of ratchet teeth formed in a surface of the shell adjacent the mounting collar and at least one pawl formed in the mounting assembly, whereby the pawl engages the ratchet teeth when the mounting assembly is joined to the collar.
References Cited (Backward Citations)
US1537519A
Cited
US2621753A
Cited
US3161491A
Cited
US3171729B1
Cited
US3171729A
Cited
US3966440A
Cited
US4133656A
Cited
US4155358A
Cited
US4154586A
Cited
US4324558A
Cited
US4326514A
Cited
US4428907A
Cited
US4530706A
Cited
US4572725A
Cited
US4543112A
Cited
US4684380A
Cited
US5638970A
Cited
US4999034A
Cited
US5110003A
Cited
US5099970A
Cited
US5297544A
Cited
US5634426A
Cited
US5720328A
Cited
US6055983A
Cited
US5969588A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-12-23 | 2006-06-24 | 2006-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-12-23 | 2010-06-24 | 2010-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-12-23 | 2014-06-24 | 2014-12-24 | $7700.00 | Window Closed / Lapsed |