← Back to Patent Explorer
US3496938A Expired / Lapsed US ⏱️ 0.0 years remaining

Contraceptive membranes and preparation thereof

Assignee: Eisai Co Ltd
•
Filing: 1967-08-17
•
Granted: 1970-02-24
•
Expires: 1987-08-17
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

No abstract record available.

Inventors

  • 👤 Kazumaro Furuse
  • 👤 Noboru Naruse
  • 👤 Kuniyuki Nakamura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 22:19
CPC Classifications
A; A61; A61F; A61F6/00; A61F6/02; A61F6/04

Claims Analysis

Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.

References Cited (Backward Citations)

US2696456A Cited
US2918404A Cited
US3342181A Cited
US3373746A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1973-02-23 1973-08-25 1974-02-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1977-02-23 1977-08-25 1978-02-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1981-02-23 1981-08-25 1982-02-24 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag