US3773590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming ribbed battery separators
Assignee: Exxon Mobil Corp
•
Filing: 1971-07-16
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Granted: 1973-11-20
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Expires: 1991-07-16
Abstract
Abstract Ribs are formed on a nonwoven mat to produce a battery separator. The ribs are formed by extruding a foamed polymer onto the nonwoven mat by extruding the foamed polymer through a multihole die as the nonwoven mat follows an arc passing over a mat backup plate. After the ribs have been extruded and the foamed polymer is still soft, the nonwoven mat with the extruded ribs may be passed through a fixed gap such as a pair of calender rolls to produce a battery separator of uniform thickness.
Inventors
- 👤 W Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:03
CPC Classifications
H; H01; H01M; H01M50/00; H01M50/40; H01M50/489; H01M50/491; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
15 words
A method according to claim 1 wherein said nonwoven mat is made of polypropylene fibers.
Claim 2
Dependent Claim
12 words
A method according to claim 2 wherein said molten polyolefin is polypropylene.
Claim 3
Dependent Claim
21 words
A method according to claim 1 wherein said nonwoven mat is first passed through a pair of fixed gap calender rolls.
Claim 4
Dependent Claim
16 words
A method according to claim 1 wherein said fixed gap is a pair of calender rolls.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |