| 摘要 |
PURPOSE:To attain not to generate a damage, an accuracy failure, etc. of a tape sliding surface of a lead groove and a lead end face of a fixed cylinder, and also to form the fixed cylinder by an inexpensive metallic mold, by forming the outside peripheral surface of the fixed cylinder less than a semi-cylinder, and also providing it as a separate body from a bearing mechanism for a rotary cylinder. CONSTITUTION:The outside peripheral surface of a fixed cylinder 3A is formed less than a semi-cylinder. That is to say, it is formed less than 180 deg. centering around a vertical axis. Therefore, as for a metallic mold for forming the outside peripheral surface having a lead groove 5, it will suffice that it is mold-released in a radial direction 7 of the fixed cylinder, and a work for a sink on the outside peripheral surface of the fixed cylinder for reducing an abrasion against a tape-shaped recording medium, a prevention of buckling of the tape-shaped recording medium, and a formation of the fixed cylinder having a clearance for a lead end face for preventing an abrasion of the lead end face can be executed. Also, since a bearing mechanism 4A of a rotary cylinder and the fixed cylinder 3A are provided as separate bodies, the respective forming metallic molds become simple and inexpensive, and also the metallic mold can be worked easily.
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