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US 4,731,767 AGranted
Timepiece having a star display
AssigneeCitizen Watch Co., Ltd.
InventorHideo Uehara
Life of this patent
Estimating the term…
Abstract
A wristwatch with a star map disk rotatably mounted in a caser and a gear train for rotating the star map disk at a speed of one revolution per one sidereal day. A star map is provided on the star map disk. The star map includes bright and constellation figures in a part of the celestial sphere which are selected from visible stars. The dial of the wristwatch has an opening for defining a range of the star map which is visible when observing.
Claims14
A timepiece comprising:
- a case;
- an hour hand operatively associated with hour wheel means, said hour wheel means being rotatably mounted in said case and including an hour wheel pinion;
- a minute hand disposed coaxially with said hour hand and operatively associated with said hour wheel means;
- a star map disk rotatably mounted in said case below said hands and disposed coaxially with said hour wheel means, said star map disk having a diameter substantially equal to the rotational diameter of said minute hand and said star map disk including a star map disk wheel operatively associated with said star map disk;
- gear train means for transmitting rotation of said hour wheel means to said star map disk to rotate said star map disk one revolution per one sidereal day, said gear train means including a regulating wheel means having
- a regulating wheel shaft rotatably mounted in said case,
- a regulating wheel gear mounted on said regulating wheel shaft and engaged with said hour wheel pinion,
- a regulating wheel pinion mounted on said regulating wheel shaft and engaged with said star map disk wheel, and friction engaging means for allowing said regulating wheel gear and
- said regulating wheel pinion to slip so as to allow said star map disk to be set without rotating said hands;
- a first star map provided on said star map disk, said first star map including stars of constellations in a part of the celestial sphere which are selected from stars visible at an observation point on the earth;
- and
- celestial defining means provided on said first star map for defining a range in said first star map which is visible at an observation point on the earth.
9 more elements
A timepiece comprising:
- a case;
- an hour hand operatively associated with an hour wheel means, said hour wheel means being rotatably mounted in said case and including an hour wheel gear and an hour wheel pinion;
- a minute hand operatively associated with said hour wheel means;
- a star map disk rotatably mounted in said case below said hands and disposed coaxially with said hour wheel means, said star map disk having a diameter substantially equal to the rotational diameter of said minute hand and including a star map disk wheel operatively associated with said star map disk;
- gear train means for transmitting rotation of said hour wheel means to said star map disk to rotate said star map disk one revolution per one sidereal day, said gear train means including a regulating wheel means having
- a regulating wheel shaft rotatably mounted in said case,
- a regulating wheel gear mounted on said regulating wheel shaft and engaged with hour wheel pinion,
- a regulating wheel pinion mounted on said regulating wheel shaft and engaged with said star map disk wheel,
- a regulating wheel boss operatively associated with said regulating wheel gear and regulating wheel pinion, and
- a friction engaging means operatively associated with said regulating wheel boss for allowing said regulating wheel gear and said regulating wheel pinion to slip so as to allow said star map disk to be set without rotating said hands;
- an intermediate correcting wheel means rotatably mounted in said case, said intermediated correcting wheel being operatively associated with said gear train means for rotating said regulating wheel means and said star map disk;
- a first star map provided on said star map disk, said star map including stars of constellations in a part of the celestial sphere which are selected from stars visible at an observation point on the earth;
- and
- celestial defining means provided on said first star map for defining a range in said first star map which is visible at an observation point on the earth.
11 more elements
Dependencies are inferred from the claim text.