US3786570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sundial
Assignee: Individual
•
Filing: 1972-07-31
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Granted: 1974-01-22
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Expires: 1992-07-31
Abstract
Abstract An improved sundial comprising a reflective surface member supported in a plane parallel with the earth''s axis and adapted to receive and reflect sun rays; a non-reflective line inscribed along said reflective surface parallel to the axis of the earth''s rotation and adapted to project a shadow; a translucent semicylindrical member projected over said surface and co-axial about said line, the surface of said cylinder carrying a time scale observable from the exterior of the translucent member such that the shadow is highlighted by a bright sunlit outline of reflected sun rays with said shadow indicating the time of day.
Inventors
- 👤 R Davies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:19
CPC Classifications
G; G04; G04B; G04B49/00; G04B49/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
A sundial comprising, in combination: a support member for supporting a mirror-finished planar reflecting surface along an angle equal to the angle of latitude of the earth; a reflecting member having a mirror-finished planar reflecting surface, the reflecting member being supported by the support member with said surface in a first plane parallel to said angle and including a non-reflective line inscribed on said surface along a path in alignment with the earth''s axis of rotation; and a semi-cylindrical member co-axial with said non-reflective line, the semi-cylindrical member being supported by said support member and spanning over the reflecting member to receive sun-ray reflections from the reflecting member.
Claim 2
Dependent Claim
108 words
A sundial comprising, in combination: a support member for supporting a mirror-finished planar reflecting surface along an angle equal to the angle of latitude of the earth; a reflecting member having a mirror-finished planar reflecting surface, the reflecting member being supported by the support member with said surface in a first plane parallel to said angle and including a non-reflective line inscribed on said surface along a path in alignment with the earth''s axis of rotation; and a semi-cylindrical member co-axial with said non-reflective line, the semi-cylindrical member being supported by said support member and spanning over the reflecting member to receive sun-ray reflections from the reflecting member.
Claim 3
Dependent Claim
24 words
The sundial of claim 1 in which the semi-cylindrical member is inscribed with a scale having a plurality of spaced increments to represent time.
Claim 4
Dependent Claim
19 words
The sundial of claim 2 in which the semi-cylindrical member is comprised of a strip of pliable translucent material.
Claim 5
Dependent Claim
57 words
The sundial of claim 1 in which the semi-cylindrical member is comprised of a translucent member in which the shadow from said non-reflective line is highlighted by the reflected sun-rays; and further including first angular-setting means for adjustably setting the angular position of said mirror-finished planar reflecting surface relative to the axis of rotation of the earth.
Claim 6
Dependent Claim
63 words
The sundial of claim 4 in which the support member is in the form of a vertical column member with an arcuate edge; and the first angular-setting means includes a horizontal member carrying a groove with said arcuate edge of the support member positioned within said groove, said vertical column being pivotable about an axis extending through and normal to said non-reflective line.
Claim 7
Dependent Claim
31 words
The sundial of claim 5 in which the first angular-setting means further includes locking means for locking said vertical column in position relative to said horizontal member at a desired angle.
Claim 8
Dependent Claim
61 words
The apparatus of claim 2 further including angular adjustment means for adjusting the relative angular position of said planar surface to a given time on said scale of the semi-cylindrical member to said planar surface, said second angular adjustment means providing for relative angular advancement and retractment of reflections from said planar surface relative to said given time on said scale.
Claim 9
Dependent Claim
98 words
The apparatus of claim 1 in which the semi-cylindrical member is inscribed with a scale having a plurality of spaced increments to represent time; first angular-setting means for adjustably setting the angular position of said mirror-finished reflecting planar surface relative to the axis of rotation of the earth; and second angular adjustment means for adjusting the relative angular position of said planar surface to a given time on said scale of the semi-cylindrical member, said second angular adjustment means providing for advancement and retractment of reflections from said planar surface relative to said given time on said scale.
Claim 10
Dependent Claim
87 words
The apparatus of claim 8 in which the second angular setting means includes an arcuate member supporting said reflecting member, said arcuate member having an axis of rotation co-axial with said non-reflective line, a gear assembly engaged to the arcuate member for rotating the arcuate member about it''s axis of rotation, said gear assembly including a drive gear integral with said reflecting member and a drive gear for driving said driven gear, said drive gear including means for receiving a drivE force to activate said gear assembly.
Claim 11
Dependent Claim
95 words
The apparatus of claim 9 in which the semi-cylindrical member is comprised of a translucent member in which the shadow from said non-reflective line is highlighted by the reflected sun-rays, said semi-cylindrical member being inscribed with a scale having a plurality of spaced increments to represent time; and further including a graphical representation of the equation of time inscribed on the underside of the semi-cylindrical member about a given scalar indication and in alignment with said mirror-reflecting surface such that the outline of said graphical representation is reflected on said surface about said non-reflective line.
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |