US3675403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame retardant air filter construction with thermoplastic scrim
Assignee: Johnson and Johnson
•
Filing: 1970-03-10
•
Granted: 1972-07-11
•
Expires: 1990-03-10
Abstract
Abstract The invention provides a scrim material permitting the use of normally combustible tackifiers in filter devices, wherein the scrim is composed of an open-network structure with air pressure drop characteristics not exceeding 0.10 inch/water measured at 500 cfm per square foot of filter medium area.
Inventors
- 👤 Angelo P Ruffo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:55
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/08; B01D39/083; B01D39/086; B01D46/00; B01D2239/00; B01D2239/04; B01D2239/0457; B01D2239/0471; B01D2239/12; B01D2239/1291
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
13 words
The product of claim 1, wherein said scrim comprises an open-network polypropylene structure.
Claim 2
Dependent Claim
15 words
The product of claim 1 wherein said normally combustible hydrocarbon tackifier is a polybutene tackifier.
Claim 3
Dependent Claim
15 words
The product of claim 1, wherein said filter medium comprises a batt of polyester fibers.
Claim 4
Dependent Claim
25 words
The product of claim 1, wherein said scrim is a flexible scrim, said scrim having a tensile strength of 5 to 13 pounds per inch.
References Cited (Backward Citations)
US2758671A
Cited
GB781194A
Cited
US3017239A
Cited
US3201926A
Cited
US3258900A
Cited
US3273321A
Cited
US3400519A
Cited
US3543940A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |