Abstract: A tape cartridge housing a tape for recording information signals has a cover plate and a pull-in inlet portion. The cover plate is rotatably supported by an opening/closure mechanism and rotated in association with movement of the opening/closure mechanism. The opening/closure mechanism, in turn, is rotatably supported by a main cartridge portion having on its front side a recess into which is intruded a tape pull-out mechanism adapted to pull out the tape. The opening/closure mechanism is adapted to open or close the recess, and the free end of the cover plate has an engagement protrusion. When the engagement protrusion is disengaged from a rotation guide groove provided on the main cartridge portion, the engagement protrusion is pull-in guided by the pull-in inlet portion into engagement with the rotation guide groove.

Abstract: A tape cassette includes tape reels and a cassette main body formed of an upper shell and a lower shell. In such a tape cassette, a tape reel position restricting portion serving as a reinforcing member for the lower shell is provided on the lower shell at a position outside an outer periphery of the lower flange. The tape reel position restricting portion includes a high rib; an intermediate rib being lower than the high rib within a range not to obstruct passing of a tape end detecting light beam, and being positioned in a tape end detecting light path; and a low rib being lower than the intermediate rib, and being positioned in a tape path region. The intermediate rib and the low rib are preferably disposed outside the high rib.

Abstract: In a reel lock mechanism for a tape cassette in which a ratchet opening spring can be easily attached to reel lock ratchets, the ratchet opening spring (14) includes two coil portions (14a, 14b) mounted on shaft portions (20d, 20d) of a pair of reel lock ratchets (12, 13) and a pair of ratchet opening arms (14d, 14e) for spring-biasing ratchet portions (20c, 20c) toward ratchet wheels (8, 8) on the tape reels (2a, 3a). The pair of reel lock ratchets (12, 13) include a ratchet-side stopper (20f) and a reel lock body (11) includes a body-side stopper (11e) which can be engaged with the ratchet-side stopper (20f). When the ratchet-side stopper (20f) and the body-side stopper (11e) are engaged with each other, the ratchet opening spring (14) generates a spring force to bias the pair of reel lock ratchets (12, 13) under such spring force.

Abstract: A tape cassette with a pivotal lid having a tape wound on reels inside a cassette made up of upper and lower shells and light holes in the sides of the cassette for detecting the ends of the tape using light beams is made easy to assemble by dustproofing ribs for preventing dust and the like from entering through the light holes each being split into two dustproofing rib parts, one of these parts being provided on the pivotal lid and the other being provided on the lower shell. The dustproofing rib parts are so disposed that with the pivotal lid in an open position the upper shell can be assembled to the lower shell easily in one straight-line movement without its direction being changed. Facing surfaces of the two dustproofing rib parts constituting each dustproofing rib are sloping or stepped to effectively prevent dust from passing between the dustproofing rib parts.

Abstract: A tape cassette having a lid attached to its front surface portion so as to become openable and closable, the lid being composed of a front lid and a back lid and in which cam bosses provided on respective side portions of the back lid are guided along cam grooves formed on a cassette housing of the tape cassette to thereby open and close the lid when the lid is opened and closed. The tape cassette comprises a retaining member formed on the cassette housing in the vicinity of an upper end portion of the cam groove, wherein when the back lid is opened, the cam boss is brought in contact with the retaining member at the position in which an upper portion of the cam boss is projected from at least a lower surface of the retaining member, thereby preventing the cam boss from being disengaged from the cam groove.

Abstract: A tape cassette includes an erasure preventing plug comprising a circular head portion, a first leg portion, a second leg portion having a diameter less than the first leg portion, and a locking projection. A lower surface of the circular head portion where it joins the first leg portion is angled. The outer diameter of the first leg portion where it connects with the lower angled surface of the circular head portion is determined so as to be generally equal to an inner diameter of a coil spring used for biasing the erasure preventing plug when the erasure preventing plug and the coil spring are mounted in a cassette casing when the coil spring is compressed so as to be in contact with the angled lower surface of the circular head portion.

Abstract: A tape cassette includes a case body consisting of an upper half case and a lower half case, a pair of hubs contained in the case body and holding a magnetic tape thereon, and a locking member placed in a recess formed in the inner surface of the lower half case so as to be brought into engagement with the respective circumferences of the hubs to lock the hubs and to be disengaged from the respective circumferences of the hubs to unlock the hubs. The locking member having a tail portion having a surface consisting of convex, curved working surfaces, and the unlocking pin of a recording/reproducing apparatus engaging either of the convex, curved working surfaces to shift the locking member to the unlocked position when the tape cassette is inserted in the recording/reproducing apparatus.

Abstract: A superconductor comprises two superconducting wires butt-jointed, a superconducting doubling wire electrically and mechanically connecting the superconducting wires, and a stabilizer attached to the superconductors and the doubling wire to extend therealong, the superconductors, the doubling wire and the stabilizer together forming a superconductor of a constant cross-sectional area. A manufacturing process is also disclosed.