| 摘要 |
<p>PURPOSE:To enable the automatic return of a cam pin in a cam mechanism suitable for rotating a tension arm with a tension regulator of a VTR by providing a return cam for returning the cam pin deviating from a gap or the like in a continuous part between a fixed cam and movable cam to the cam surface. CONSTITUTION:When a drive motor is rotated in one rotation in a popping-up type VTR, a slide chassis 3 slides through a gear train or the like toward the rotary head drum side and a cam pin 26 is moved along a first cam surface 24a of a fixed cam 22 to pivot a tension arm 9 counterclockwise. When the chassis 3 slides further and the cam pin 26 is moved along a second cam surface 24b to a position of a third cam surface 31 of a movable cam 23, the chassis 3 is stopped. Then, when the cam pin 26 is moved from the cam surfaces 24b to 31 and deviated from a gap 32 between both, the chassis 3 is returned so that the cam pin 26 can be returned to the second cam surface 24b by means of a return cam 27.</p> |
