| 摘要 |
PROBLEM TO BE SOLVED: To provide a crank device which equalizes the turning time required when a turning member moves back and forth. SOLUTION: An antenna driving device comprises a crank device which is constituted of a first and a second crank arms 11, 12, a driving motor 1, and an antenna 2. One end of the first crank arm 11 is fixed to an output shaft 9 of the driving motor 1, while one end of the second crank arm 12 is connected to the other end of the first crank arm 11 by means of a connecting pin 10. A turning end of an arm plate 8 is connected to the other end of the second crank arm 12 by means of a connecting pin 13. A turning center C of the driving motor 1 is positioned on a virtual straight line 30 which passes through the both ends (points A, B) of a moving locus 16 of a connecting part for the arm plate 8 and the second crank arm 12.
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