Patent DE78030C successfully refreshed from Google Patents.
US4003545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Core means having a rubber liner
Assignee: Individual
•
Filing: 1974-09-13
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Granted: 1977-01-18
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Expires: 1994-09-13
Abstract
Abstract A core member used in a moulding flask for making prefabricated concrete products, comprising a hollow tubular member of predetermined size having all outer surfaces intended to be in contact with concrete mixture covered by a thin layer of rubber plate.
Inventors
- 👤 Minoru Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:15
CPC Classifications
B; B28; B28B; B28B21/00; B28B21/86; B28B21/88; B28B7/00; B28B7/28; B28B7/30; Y; Y10; Y10S; Y10S425/00; Y10S425/044
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
175 words
A core device used in a moulding flask for making prefabricated concrete product, said device comprising a hollow tubular member formed from a rigid material and having an outer surface, a thin layer of rubber freely laid over the outer surface of said hollow tubular member, said thin layer of rubber having an outer surface for engaging and retaining concrete mixture poured into said moulding flask, said outer surface of the hollow tubular member being a truncated conical surface diverging toward the upper end of the tubular member, said thin layer of rubber having an inside surface which is a truncated conical surface diverging toward the upper end of the tubular member so as to mate with the outer surface of the hollow tubular member, and further said thin layer being secured at its upper edge portion to the top of the tubular member and having a bent portion protruding above the upper end of the tubular member, extending radially inwardly, and sloping downwardly to the upper edge portion of the thin layer of rubber.
Claim 2
Dependent Claim
175 words
A core device used in a moulding flask for making prefabricated concrete product, said device comprising a hollow tubular member formed from a rigid material and having an outer surface, a thin layer of rubber freely laid over the outer surface of said hollow tubular member, said thin layer of rubber having an outer surface for engaging and retaining concrete mixture poured into said moulding flask, said outer surface of the hollow tubular member being a truncated conical surface diverging toward the upper end of the tubular member, said thin layer of rubber having an inside surface which is a truncated conical surface diverging toward the upper end of the tubular member so as to mate with the outer surface of the hollow tubular member, and further said thin layer being secured at its upper edge portion to the top of the tubular member and having a bent portion protruding above the upper end of the tubular member, extending radially inwardly, and sloping downwardly to the upper edge portion of the thin layer of rubber.
Claim 3
Dependent Claim
114 words
A core device used in a moulding flask for making prefabricated concrete product, said device comprising a hollow tubular member formed from a rigid material and having an outer surface, a thin tubular layer of rubber freely laid over the outer surface of the hollow tubular member, said thin layer of rubber having an outer surface for engaging and retaining concrete mixture poured into said moulding flask, a pair of movable plates attached to the respective opposite ends of the thin layer of rubber, and a pair of jack means attached to the respective pair of plates and the respective opposite ends of the hollow tubular member for elongating the thin layer of rubber.
Claim 4
Dependent Claim
114 words
A core device used in a moulding flask for making prefabricated concrete product, said device comprising a hollow tubular member formed from a rigid material and having an outer surface, a thin tubular layer of rubber freely laid over the outer surface of the hollow tubular member, said thin layer of rubber having an outer surface for engaging and retaining concrete mixture poured into said moulding flask, a pair of movable plates attached to the respective opposite ends of the thin layer of rubber, and a pair of jack means attached to the respective pair of plates and the respective opposite ends of the hollow tubular member for elongating the thin layer of rubber.
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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) | 1980-01-18 | 1980-07-19 | 1981-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-18 | 1984-07-19 | 1985-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-18 | 1988-07-19 | 1989-01-18 | $7700.00 | Window Closed / Lapsed |