| 摘要 |
<p>PURPOSE:To reduce a load of a control motor, and to microminiaturize it, by providing a limiter spring between a head substrate driven by a pinch pressure spring and a limiter plate, and providing a negative spring between the limiter spring and a chassis. CONSTITUTION:A limiter plate 54 is slidingly engaged to guide pins 56a, 56b of a head substrate 20 energized in the forward moving direction by a pinch pressure spring 48, and a limiter spring 58 is provided between them. Also, a negative spring 60 is extended between an arm part 54a of the plate 54 and a chassis 19. Accordingly, force which is applied through the substrate 20 and the limiter plate 54 to a crank pin 50 rotated by a control motor for switching a mode becomes that which is obtained by subtracting the spring pressure of the negative spring 60 from the force of the pinch pressure spring 48, a load of the pin 50 becomes very small in both forward and backward motions, a load of the control motor is also reduced, and a micromotor can be used.</p> |
