US3682068A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light envelope
Assignee: Polaroid Corp
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Filing: 1969-06-11
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Granted: 1972-08-08
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Expires: 1989-06-11
Abstract
Abstract An opaque envelope for utilization in a photographic camera, said envelope comprising a light-transmitting chamber which excludes extraneous light, and which is fabricated of an ethylene-propylene-diene rubber.
Inventors
- 👤 Frank M Stieger
- 👤 Polaroid Corp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:27
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/02; G03B17/04; G03B11/00; G03B11/04; G03B11/046
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
198 words
A molded opaque light path envelope for use in a folding camera, said envelope having: a main body section of generally frustro-pyramidal shape including openings at opposite ends and in a wall thereof; and a secondary section in the shape of a tapered tube open at one end and joined at its other end to said wall of said main body section surrounding said opening therein; and attachment means secured to said sections around said openings at said ends thereof for attaching said envelope to said camera at said openings; said main body section having a wall thickness of less than 30 mils; said secondary section having a wall thickness of less than 20 mils.; said envelope comprising a vulcanized, photographically inert terpolymer of 35 to 80 mole percent ethylene, 5 to 64 mole percent propylene, and 1 to 15 mole percent diene and sufficient carbon black to render said terpolymer opaque; said carbon black containing terpolymer possessing, over a temperature range of -20* to 200* F., a Shore A durometer hardness of 40 to 80, the capability of repeated elongations of more than 100 percent without flexural cracking, negligible tensile set and good abrasion and tear resistance.
Claim 2
Dependent Claim
198 words
A molded opaque light path envelope for use in a folding camera, said envelope having: a main body section of generally frustro-pyramidal shape including openings at opposite ends and in a wall thereof; and a secondary section in the shape of a tapered tube open at one end and joined at its other end to said wall of said main body section surrounding said opening therein; and attachment means secured to said sections around said openings at said ends thereof for attaching said envelope to said camera at said openings; said main body section having a wall thickness of less than 30 mils; said secondary section having a wall thickness of less than 20 mils.; said envelope comprising a vulcanized, photographically inert terpolymer of 35 to 80 mole percent ethylene, 5 to 64 mole percent propylene, and 1 to 15 mole percent diene and sufficient carbon black to render said terpolymer opaque; said carbon black containing terpolymer possessing, over a temperature range of -20* to 200* F., a Shore A durometer hardness of 40 to 80, the capability of repeated elongations of more than 100 percent without flexural cracking, negligible tensile set and good abrasion and tear resistance.
Claim 3
Dependent Claim
19 words
An envelope as defined in claim 1 wherein said carbon black level is more than 70 percent by weight.
Claim 4
Dependent Claim
15 words
An envelope as defined in claim 1 wherein the vulcanization of said terpolymer is non-sulfurous.
Claim 5
Dependent Claim
20 words
An envelope as defined in claim 1 wherein said diene comprises a non-conjugated diene having at least six carbon atoms.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |