| 摘要 |
<p>PURPOSE:To accurately rotate the revolving member with a simple constitution and to accommodate the magnetic tape device of this invention itself to the multifunctioning, by constituting the device in such a way that prescribed rotations of the revolving body in accordance with each kind of operating condition are performed by means of the abutment of the cam surface of the revolving body to the revolving body and the cam surface is separated from the revolving body in the reproducing condition. CONSTITUTION:The end face 51 of a tension arm 45 abuts to the 1st-3rd cam surfaces of a sub-cam 142 arranged to the back of a base plate 2 through a hole 55 installed into the base plate 2 in accordance with the operating condition of this device. A band fastener 57a is placed on the tension arm 45 under a rotation-free condition and a band 59 is stretched between the band fastener 57a and another band fastener 57b fixed to the base plate 2 after the band 59 is put around a feed reel base 12. While it is in a stopping mode as shown by the diagram when the rotating angle of the sub-cam 142 is 0 deg., a post 47 is positioned at the opening section of a cassette 20, because the end face 51 of the tension arm 45 contacts with the 1st cam surface and controls the anticlockwise rotation of the tension arm 45.</p> |
