Patent US4026575A successfully refreshed from Google Patents.
US4026575A
Expired / Lapsed
US
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Plastic ski
Assignee: SMS Siemag AG
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Filing: 1975-12-08
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Granted: 1977-05-31
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Expires: 1995-12-08
Abstract
Abstract Plastic ski of compound structure consisting of a running surface with steel edges, a lower strap, an upper strap, and a cover layer, the upper and the lower straps being connected to each other by an injected core of plastic foam.
Inventors
- 👤 Peter Rudolf Hartwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:37
CPC Classifications
A; A63; A63C; A63C5/00; A63C5/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
106 words
Plastic ski of compound structure, consisting of a running surface with steel edges, a carrying lower strap, a carrying upper strap and a cover layer, whereby the upper and lower straps are connected by plastic foam which is injected into the core, characterized by the fact that the core (5) has at least three sections over its length and at least two different densities of plastic foam and the center section of the core (5) has a lower density than the two end sections, and that the individual sections of the core (5) are connected with each other by an obstruction (12) made of fiber glass.
Claim 2
Dependent Claim
106 words
Plastic ski of compound structure, consisting of a running surface with steel edges, a carrying lower strap, a carrying upper strap and a cover layer, whereby the upper and lower straps are connected by plastic foam which is injected into the core, characterized by the fact that the core (5) has at least three sections over its length and at least two different densities of plastic foam and the center section of the core (5) has a lower density than the two end sections, and that the individual sections of the core (5) are connected with each other by an obstruction (12) made of fiber glass.
Claim 3
Dependent Claim
30 words
Plastic ski as recited in claim 1, characterized by the fact that the density of the core (5) in the end sections is approximately twice that of the center section.
Claim 4
Dependent Claim
50 words
Plastice ski as recited in claim 1, characterized by the fact that the density of core (5) in the center section is in the range from 0.3 to 0.65 grams per cubic centimeter and in the end sections is in the range from 0.8 to 1.1 grams per cubic centimeter.
Claim 5
Dependent Claim
34 words
Plastic ski as recited in claim 1, characterized by the fact that the center section of the core is made from polyurethane-duromer-hard foam and the end sections are made from an elastic polyurethane-integral foam.
References Cited (Backward Citations)
US2213903A
Cited
US2995379A
Cited
US3493240A
Cited
US3498626A
Cited
US3503621A
Cited
US3771805A
Cited
US3733380A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |