Abstract: An improved guide member assembly in a cassette for guiding the travel of web-like data carrying material includes a support base provided on the cassette, a supporting shaft mounted on the support base, guide means rotatably mounted on the supporting shaft having a peripheral data carrying material guiding surface and fluid lubricant disposed between the supporting shaft and guide means. A device is provided for reliably preventing any of such fluid lubricant from accumulating on and adhering to the data carrying material guiding surface of the guide means.

Abstract: A magnetic disc cartridge is composed of a pair of upper and lower case members so as to form a hard case to accommodate a magnetic disc therein. An aperture for access of a read-write head to the magnetic disc extends in a radial direction, which aperture is selectively covered by a shutter. The case has a groove on the peripheral edge thereof to receive a shutter actuation pin. The groove extends across the adjoining surfaces of the two case members. A groove portion defined by the lower case member is more enlarged than the remaining groove portion defined by the upper case member so that the shutter actuation pin does not catch in the step between the two groove portions.

Abstract: A magnetic disk cartridge used for memory means for a computer, which comprises a hard case composed of a cover member and a bottom member, and a magnetic disk having a central hole in which a pivot shaft of disk drive means is inserted. An anti-abrasion chip having a polygon shape including a triangle is attached to the inside of the cover member so as to receive the free tip of the pivot shaft of the disk drive means in contact therewith while the magnetic disk is rotated within the hard case. The shape of the anti-abrasion chip is a regular triangle, a right-angled triangle, an isosceles triangle, a square, a rectangle, a trapezoid or the like. A producing method for a magnetic disk cartridge is also disclosed. The anti-abrasion chip having a polygon shape including a triangle is made by cutting an anti-abrasion sheet attached to a base sheet without causing a disuse portion thereof.

Abstract: A disk cartridge comprises a hard casing in which a magnetic disk is rotatably contained, wherein a wear-resistance material is provided at at least a part of a contacting area between a hub of the magnetic disk and the hard casing.

Abstract: A disk cartridge having a hard casing in which a magnetic disk with a hub is rotatably received. A stepped portion is formed at a peripheral edge portion of a contacting surface of the hub which is in contact with a supporter on a driving unit to support rotation of the hub, thereby increasing flatness in the contacting surface.

Abstract: A magnetic disc cartridge is composed of a pair of upper and lower case members superimposed one upon the other so as to form a hard case to accommodate a magnetic disc therein. An aperture for access of a read-write head to the magnetic disc extends in a radial direction, which aperture is selectively covered by a shutter. The case has a groove on the peripheral edge thereof to receive a shutter actuation pin. The groove extends across the adjoining surfaces of the two case members and is formed by a wall member extending integrally from one of the two case members towards the other so as to hide a joining line between the two case members.

Abstract: A disk cartridge comprises upper and lower hard casings whose inner surfaces are respectively attached with lining sheets and the upper and lower hard casings receives a magnetic disk in a rotatable manner. Elastic pieces are respectively provided on the inner surfaces of the upper and lower hard casings at opposing positions and each of the elastic members is interposed between a lining sheet and the upper and lower hard casings.

Abstract: A disk cartridge comprises a hard casing which receives a magnetic disk with a hub in a rotatable manner and the lower surface of a circular recess of the hub is slightly raised from its outer peripheral portion toward the central opening of the hub in which the driving pin of a driving unit is fitted.

Abstract: A magnetic tape cassette comprises at least one reference hole formed in either of upper and lower casings so as not to prevent the running of a magnetic tape, at least one reference boss formed in the other one of the casings in alignment with the reference hole to be closely fitted thereto, and guide supporting members for holding guide members positioned at a given distance from the reference hole and the reference boss.