| 摘要 |
PURPOSE:To prevent tapes on the A and B sides of a cassette half from the generation of phase difference and to attain fine reproducing by rotating a metal mold body on the same horizontal surface by a specific angle, replacing the front and back of the metal mold body and then drilling a hollow part on the other side. CONSTITUTION:A hollow part 41 for producing a pin of the cassette half 1 is formed on the metal mold body 2 by a drill 5 at first, the metal mold body 2 is replaced at its front and back by turning the body 2 on the horizontal surface by 180 deg. around the drill 5 set up on a prescribed position and then a hollow part 42 for forming the other pin of the cassette half 1 is formed on the metal mold body 2 by the drill 5. Thus, regarding the inclined angles thetaA, thetaB in the front direction formed by two pins 31, 32 produced by the two hollow parts 41, 42 the relation of thetaA -thetaB is established. Since the tape D is moved without shift from the rotational direction and wound at the movement such as reproducing, fast-forwarding, rewinding and sound recording, the generation of the phase difference on the A and B sides of the cassette half 1 can be suppressed at its minimum.
|
