US4741689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection mold for an optical disk
Assignee: Daicel Corp
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Filing: 1986-10-30
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Granted: 1988-05-03
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Expires: 2006-10-30
Abstract
Abstract An injection mold for injection molding a plastic substrate for high-density information recording medium. An annular sliding member is axially slidably supported in the circumference of a disk-shaped cavity of a mold half. The annular sliding member is biased toward the surface of a disk-shaped cavity provided in another mold half so as to form the molding cavity and maintain contact with said surface during molding of said plastic substrate.
Inventors
- 👤 Yoshio Onizawa
- 👤 Yasushi Hiramatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:28
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/26; B29C45/263; B29C45/2608; B29C2045/2648; B29C2045/2657; B29C45/0025; Y; Y10; Y10S; Y10S425/00; Y10S425/808; Y10S425/812
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
162 words
An injection mold for injection molding a plastic substrate for a high-density information recording medium, comprising: (a) first and second half molds each having a disk-shaped cavity, said cavity of said first half mold facing said cavity of said second half mold, said half molds being movable relative to each other so as to form a disk-shaped molding cavity therebetween; (b) a means for injecting molten plastic into said disk-shaped molding cavity; (c) an annular sliding member axially slidably supported around the outer circumference of said disk-shaped cavity of said first half mold; (d) biasing means in said first half mold for biasing said annular sliding member toward the disk-shaped cavity surface of said second half mold; and (e) an annular outer ring and a stamper attached to said second half mold, said annular outer ring and said stamper maintaining a constant clearance with a portion of said annular sliding member to provide a gas vent when said molding cavity is formed.
Claim 2
Dependent Claim
162 words
An injection mold for injection molding a plastic substrate for a high-density information recording medium, comprising: (a) first and second half molds each having a disk-shaped cavity, said cavity of said first half mold facing said cavity of said second half mold, said half molds being movable relative to each other so as to form a disk-shaped molding cavity therebetween; (b) a means for injecting molten plastic into said disk-shaped molding cavity; (c) an annular sliding member axially slidably supported around the outer circumference of said disk-shaped cavity of said first half mold; (d) biasing means in said first half mold for biasing said annular sliding member toward the disk-shaped cavity surface of said second half mold; and (e) an annular outer ring and a stamper attached to said second half mold, said annular outer ring and said stamper maintaining a constant clearance with a portion of said annular sliding member to provide a gas vent when said molding cavity is formed.
Claim 3
Dependent Claim
12 words
The injection mold of claim 1 wherein said biasing means comprises springs.
Claim 4
Dependent Claim
14 words
The injection mold of claim 1 wherein said biasing means comprises a hydraulic mechanism.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-03 | 1991-11-02 | 1992-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-03 | 1995-11-02 | 1996-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-03 | 1999-11-02 | 2000-05-03 | $7700.00 | Window Closed / Lapsed |