US4844492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two wheeled roller skate
Assignee: Individual
•
Filing: 1988-03-28
•
Granted: 1989-07-04
•
Expires: 2008-03-28
Abstract
Abstract A two wheel roller skate has a roller that has two distinct surfaces consisting of a central part that is a curved surface and matching right and left frusto conical sections that have an angle that equals the degree of arc in the central part measured from the central point of the central part's arc providing greatly improved maneuverability.
Inventors
- 👤 Edward E. Ludwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:17
CPC Classifications
A; A63; A63C; A63C17/00; A63C17/04; A63C17/06; A63C17/061; A63C17/064
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
165 words
A roller skating device comprising in combination a supporting plate for engagement to footwear of a skater and a pair of longitudinally spaced roller wheel assemblies, each wheel assembly comprising a hanger having a roller-supporting forked bracket extending from the plate, resilient mounting means for pivotally securing each hanger to said supporting plate, and a roller rotatably secured to said forked bracket, each roller having a central section with a transversely curved surface and a frusto-conical end section of decreasing diameter extending from each side of said central section, the combined length of said central section and said end sections being substantially greater than the largest diameter of said central section, wherein the angle of taper, as measured from a line extending parallel to the axis of the roller, of each end section is equal to one half of the arc of curvature of said central section and is also equal to the angle of inclination occurring at the outer boundary of said central section.
Claim 2
Dependent Claim
165 words
A roller skating device comprising in combination a supporting plate for engagement to footwear of a skater and a pair of longitudinally spaced roller wheel assemblies, each wheel assembly comprising a hanger having a roller-supporting forked bracket extending from the plate, resilient mounting means for pivotally securing each hanger to said supporting plate, and a roller rotatably secured to said forked bracket, each roller having a central section with a transversely curved surface and a frusto-conical end section of decreasing diameter extending from each side of said central section, the combined length of said central section and said end sections being substantially greater than the largest diameter of said central section, wherein the angle of taper, as measured from a line extending parallel to the axis of the roller, of each end section is equal to one half of the arc of curvature of said central section and is also equal to the angle of inclination occurring at the outer boundary of said central section.
Claim 3
Dependent Claim
36 words
A roller skating device as in claim 1 wherein the arc of curvature is substantially equal to 22 degrees and the frusto-conical sections have an angle of taper of substantially 11 degrees from the central section.
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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) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |