Abstract: An erase prevention device for use in a recording medium casing to selectively inhibit recording on a recording medium contained in the recording medium casing when the casing is placed in a recorder. The device comprises coaxial holes formed in the recording medium casing to provide an injection passage. A slider is guided for sliding movement in the recording medium casing between first and second positions. The slider opens the inspection passage in the first position to inhibit recording and closes the inspection passage in the second position to allow recording. An aperture is formed in the recording medium casing for providing a visible indication of the position of the slider. The slider opens the aperture in the first position and closes the aperture in the second position. With this arrangement, the position of the slider is apparent at a glance to prevent mistake.

Abstract: In a tape cassette having supply and take-up reels on which a tape extending between the reels is wound, a cassette housing containing the reels, leaf springs for urging the reels toward the lower portion of the housing, and headed pins depending from an upper portion of the housing through holes in the leaf springs for mounting the latter; each leaf spring has a surface portion adjacent the respective hole formed with fine convex and concave irregularities and being engaged by the respective headed pin for securely holding the leaf springs against turning and wobbling about the headed pins.