Patent ID: 6431746
Filing Date: 2002-08-13
Classification: G04C

Abstract:
A mechanical timepiece comprising:a power source comprised of a mainspring for undergoing rewinding movement to generate a rational force; a front train wheel for undergoing rotation in accordance with a rotational force generated during rewinding movement of the mainspring; an escapement/speed-control device for controlling rotation of the front train wheel, the escapement/speed-control device having a balance with a hairspring for undergoing alternatively repeating rotational movement in left and right directions; an escape wheel and pinion for undergoing rotation in accordance with rotation of the front train wheel; a pallet fork for controlling rotation of the escape wheel and pinion in accordance with rotational movement of the balance; a switch mechanism for outputting an ON signal when a rotation angle of the balance reaches a predetermined threshold angle or greater, and for outputting an OFF signal when the rotation angle of the balance does not exceed the predetermined threshold angle; and a rotation angle control mechanism for suppressing rotation of the balance when the switch mechanism outputs an ON signal.