Patent US3821333A successfully refreshed from Google Patents.
US3821333A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gasket for lens mold from a blend of epdm and ethylene/vinyl acetate copolymer
Assignee: American Optical Corp
•
Filing: 1973-03-21
•
Granted: 1974-06-28
•
Expires: 1993-03-21
Abstract
Abstract A ''''T'''' gasket for lens molds, formed of a mixture of ethylene copolymers such as poly(ethylene-vinyl acetate) and poly(ethylene-propylene-diene) with no plasticizers, additives, or release agents required for its use.
Inventors
- 👤 B Goodwin
- 👤 D Rotenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:31
CPC Classifications
B; B29; B29D; B29D11/00; B29D11/00009; B29D11/00413; B29C; B29C33/00; B29C33/0038; B29D11/0048; B29D11/00528; C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0846; C08L23/0853; C08L23/16; B29L; B29L2031/00; B29L2031/76; B29L2031/7602; Y; Y10; Y10S; Y10S425/00; Y10S425/808; Y10T; Y10T428/00; Y10T428/21; Y10T428/215
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
27 words
A gasket for lens molds according to claim 1 wherein said polymerized material is sufficiently resilient to completely seal the peripheral edge of mounted mold elements therein.
Claim 2
Dependent Claim
32 words
A gasket for lens molds according to claim 1 wherein the quantity of ethylene-vinyl acetate copolymer is about 25-50 weight percent and the quantity of ethylene-propylene-diene interpolymer is about 75-50 weight percent.
Claim 3
Dependent Claim
24 words
A gasket for lens molds according to claim 1 wherein said gasket is molded to the desired shape for use in a lens mold.
Claim 4
Independent Claim
51 words
A method of forming a gasket for a lens mold comprising intimately mixing from 25-75 weight percent a pelletized thermoplastic ethylene/vinyl acetate copolymer with from 75-25 weight percent of a pelletized thermoplaastic ethylene-propylene-diene interpolymer, injection molding said mixture into the desired shape, and then placing the resultant gasket in lens mold.
Claim 5
Dependent Claim
27 words
A method according to claim 5 wherein about 25-50 weight percent of ethylene-vinyl acetate is mixed and molded with about 50-75 weight percent of ethylene-propylene-1,4-hexadiene inter polymer.
Claim 6
Dependent Claim
32 words
A gasket for lens molds according to claim 1 wherein the quantity of ethylene-vinyl acetate is about 37.5 weight percent and the quantity of ethylene-propylene-1, 4-hexadiene interpolymer is about 62.5 weight percent.
Claim 7
Independent Claim
58 words
A method of forming a gasket for a lens mold comprising intimately mixing from 25-50 weight percent of a pelletized thermoplastic ethylene-vinyl acetate copolymer with 75-50 weight percent of a pelletized thermoplastic ethylene-propylene-1, 4-hexadiene interpolymer, injection molding said mixture into the desired shape, curing said mixture, and then placing the resultant gasket in lens mold without further treatment.
Claim 8
Dependent Claim
23 words
Amethod according to claim 5 wherein about 37.5 weight percent of ethylene-vinyl acetate is mixed with about 62.5 weight percent of poly(ethylene-propylene-1, 4-hexadiene).
Claim 9
Dependent Claim
18 words
A gasket for lens molds according to claim 1 wherein the gasket is a T-shaped lens mold gasket.
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) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |