| 摘要 |
<p>PURPOSE:To obtain a control device which can set a tape tension in a wide range in a limited space by engaging a first elastic member with a tension arm at all times and a second elastic member with the tension arm when necessary. CONSTITUTION:When a high tape tension is to be set, a voltage is impressed to a plunger 8, so that a movable part 8a is moved in a direction M. A pre- pressing member 10 expands a tension spring 12 having a spring load and a spring constant set at low values and a tension spring 13 having a spring load set high and a spring constant set low. Accordingly, a relatively large rotary force is impressed to a tension arm 2. On the other hand, when a low tape tension is required, a voltage is not applied to the plunger 8 and the pre-pressing member 10 is drawn in an opposite direction to the direction M. The pre- pressing member 10 is moved until a stopper pin 11 butts against one end of a guide groove 10a. In consequence, an urging force of the tension spring 13 is not impressed to the tension arm 2, but merely a weak urging force of the tension spring 12 gives a relatively small rotary force to the tension arm 2.</p> |
