| 摘要 |
<p>PURPOSE: To press a touch roller against a magnetic tape at a constant pressure by properly moving the touch roller in accordance with a change of a winding diameter of the magnetic tape taken up on a tape reel. CONSTITUTION: An overload sensor 194 is inserted into an outer circumferential part of an overload detecting member. Consequently, an overload generated on a roller arm 214 is detected by the sensor 194 to stop rotating drive of a motor 182 immediately. A moving amt. of the arm 214 is accurately adjusted by a roller arm moving mechanism part 107 with a gear part 201 provided on one side surface part of the arm 214. Thus, the arm 214 is highly accurately moved in accordance with a changing amt. of a winding diameter of the magnetic tape taken up on the supply side reel by the moving mechanism part 107. Then, the moving mechanism part 107 is provided with a contact pressure sensor 193 and a contact pressure detecting member 184 to detect a revolving speed of the motor 182. Then, a contact pressure of the touch roller 219 against the magnetic tape is detected by the moving mechanism 107 to operate the arm 214 to give a constant contact pressure for the roller.</p> |
