Seiko Clock Inc.

Seikosha Co., Ltd.

Shigeru Kohata

Takumi Matsuda

Hiroyuki Hashizume

A rotary decoration driving device comprises a case, a first rotary shaft having a first end portion rotatably supported by the case and a second end portion supporting a first decoration for rotation therewith. A second rotary shaft is mounted on the first rotary shaft for rotation therewith and has an end portion supporting a second decoration for rotation therewith. A first gear is mounted on the first rotating shaft for rotation therewith, and a second gear is mounted on the second rotating shaft for rotation therewith. At least one intermediate gear is driven to undergo intermittent rotation. A transmitting device transmits the intermittent rotation of the intermediate gear to the first and second gears. A smoothing device smoothens the intermittent rotation of the intermediate gear to thereby transmit a smooth and continuous rotary motion to the first and second gears.

Rotary decoration driving device

A clock movement includes a circuit board, first and second motors, a minute wheel connected to the first motor by a first gear train and an hour wheel connected to the second motor by a second gear train. The first and second gear trains preferably extend in a first direction, and the first and second motors are respectively disposed on opposite sides of the first and second gear trains and extend in a second direction transverse to the first direction. A first detection device detects when the minute hand is in a predetermined reference position and a second detection device detects when the hour wheel is in a predetermined reference position. The first detection device includes a minute detection sensor mounted on the circuit board and having a first light-emitting device and a first light-receiving device. The second detection device includes an hour detection sensor mounted on the circuit board and having a second light-emitting device and a second light-receiving device. The clock movement has a simple construction and is easy to manufacture, is suited to mass-production and can be manufactured at low cost.

Growing community of inventors

Tokyo, Japan

Shigeru Kohata