US3873288A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Respirator filter construction
Assignee: Draegerwerk AG and Co KGaA
•
Filing: 1972-07-17
•
Granted: 1975-03-25
•
Expires: 1992-07-17
Abstract
Abstract A respirator filter construction comprises a folded filter layer with a ring enclosing its edge which is formed by two ring parts each of which are provided with projections which correspond to the fold line intervals of the filter layer and which interlock to bear tightly with their end faces on respective sides of the folded filter web.
Inventors
- 👤 Karl August Wachter
- 👤 Horst Muller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:28
CPC Classifications
A; A62; A62B; A62B23/00; Y; Y10; Y10S; Y10S55/00; Y10S55/31; Y10S55/35
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
87 words
A respirator filter comprising a folded filter layer and a ring enclosing the periphery of said filter layer, said ring including two outer identical interengageable annular ring parts each ring part having opposed edges with complimentary projections and recesses corresponding to the folds of said filter layer which are correlated and interengaged together over the folds of the filter layer and bear tightly against respective sides of the filter layer, and a cement disposed on said projections and recesses and securing each ring to said filter layer.
Claim 2
Dependent Claim
87 words
A respirator filter comprising a folded filter layer and a ring enclosing the periphery of said filter layer, said ring including two outer identical interengageable annular ring parts each ring part having opposed edges with complimentary projections and recesses corresponding to the folds of said filter layer which are correlated and interengaged together over the folds of the filter layer and bear tightly against respective sides of the filter layer, and a cement disposed on said projections and recesses and securing each ring to said filter layer.
Claim 3
Dependent Claim
32 words
A respirator filter, according to claim 1, wherein at least one of said ring parts includes an outwardly extending flange providing a guide for inserting the filter element into a filter housing.
Claim 4
Independent Claim
87 words
A method for producing a filter element for respirators using two identical ring parts each having opposed edges with interengageable complimentary projections and recesses, comprising folding a filter web to form a plurality of pleats, arranging the folded web between the two oppositely arranged ring parts which have projections and recesses of a number and spacing corresponding to the pleats, coating the projections and recesses of the ring parts with cement and bringing the ring parts together over the foldeD filter web to secure the parts together.
Claim 5
Independent Claim
87 words
A method for producing a filter element for respirators using two identical ring parts each having opposed edges with interengageable complimentary projections and recesses, comprising folding a filter web to form a plurality of pleats, arranging the folded web between the two oppositely arranged ring parts which have projections and recesses of a number and spacing corresponding to the pleats, coating the projections and recesses of the ring parts with cement and bringing the ring parts together over the foldeD filter web to secure the parts together.
Claim 6
Dependent Claim
77 words
A method for producing a filter element for respirators, according to claim 3, wherein the ring parts are provided with spaced projections and recesses which interengage and which correspond in dimension to the pleats of the filter so that they hold the filter in the pleated form and wherein the ring parts are interengaged over the filter web and connected with it in a manner to cause substantially complete contact engagement between said pleats and said projections.
References Cited (Backward Citations)
US3183286A
Cited
US5334166A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |