Abstract: This invention relates to a tape protecting cover of a video tape cartridge, especially to a shaft having a groove the shaft being formed integrally with the tape protecting cover. A first and second molds 12 and 14 divided by the parting line 20 have dents 16 and 18 respectively to form a space when both molds are joined. The dent 16 of the first mold 12 is provided with a rectangular pin 22 for forming a groove so that its one end surface 22a may abut to the end wall surface 16a of the dent 16. The front side 22b of the rectangular pin 22 extends so as to extrude to the dent 18 of the mold 14, and is constructed to form an inclined surface 22c between the end surface 22a of the rectangular pin 22 and itself. The end wall surface 18a of the dent 18 of the second metallic mold 14 is formed to have a same inclined angle .theta. as the rectangular pin so as to abut to the inclined surface 22c of the rectangular pin 22 when both metallic molds are joined.

Abstract: A mold for stepwise molding by two or more injection shots of different materials or colors comprises fixed and movable mold halves and a slide core which combinedly form a first cavity and, with the slide core moved down, a second cavity for the shots to form a molded article of unitary structure, such as a housing section of an audio cassette tape with a see-through window. Ribs are formed on the slide core along its peripheries, and a land projection is formed on the inner side of the fixed mold half to be in contact with the molding surface of the slide core recessed with respect to the ribs. The inner peripheral wall faces of the ribs and the peripheral wall faces of the land projection of the fixed mold half are spaced apart to remain out of contact during mold clamping.

Abstract: In a case for holding a magnetic tape cassette comprising a lid and an inner enclosure formed of a planar bottom wall portion having a pair of spool stops projecting inwardly from its inner side and edge walls formed along the periphery of the bottom portion excepting a part of it and extending perpendicularly to that portion, one of the edge walls being formed with a thumb recess, the inner enclosure is made by a mold with a gate inlet so that the bottom portion has a gate mark on its outer side at a point where that portion meets the edge wall formed with the thumb recess, at a right angle to it, and underneath the recess. The planar bottom portion and peripheral edge walls are molded together in one piece. The gate mark is located at the point on an extension of a line intersecting the midpoint of a straight line that connects the two spool stops, on the outer side of the planar bottom portion, and extending at right angles to the straight line.

Abstract: A magnetic tape cassette comprises upper and lower casings to be assembled together and tape reels held in the assembled casings wherein the lower casing is provided with first reference holes at positions corresponding to reference pins formed in a magnetic tape cassette deck, to be fitted into the pins and second reference holes are formed in the upper casing so as to have the same center axis as that of the first reference holes, dimensions of all structural elements of the upper and lower casings being determined on the basis of both the reference holes.

Abstract: A hub of a tape cassette comprising a generally circular outer ring portion (6), an inner ring portion (8) concentric with the outer portion and a generally annular rib (10) connecting the outer and inner ring portions, wherein said annular rib is formed so that its wall thickness increases continuously from a position (A) adjacent to a gate portion (G) for injection molding towards a portion (B) most apart from the gate portion, along the circumferential direction.

Abstract: A magnetic tape cassette provided with a separating sheet interposed between a magnetic recording tape and a half casing. The separating sheet is provided with first protrusions projecting toward the tape and second protrusions projecting toward the half casing.

Abstract: A protective sheet for a cassette holding a magnetic recording tape comprises a transparent base which is coated with a hardened surface layer formed by bonding hard fine particles with a binder.

Abstract: A lubricant sheet for a magnetic tape cassette characterized in that at least one side of a base incorporating an antistatic agent is provided with a release type silicone coating. This lubricant sheet combines the transparency derived from the use of the clear base and coating materials with the low friction characteristic and the antistatic property to suit the application as such for transparent tape cassette cases.

Abstract: A magnetic tape cassette comprises an upper half casing and a lower half casing provided with a screw holder having a threaded hole at the corner of the lower half casing for connecting said upper half casing, wherein the thickness of the wall of the screw holder facing inside the casing is reduced and at least one rib having a level flush with the fitting surface of the lower half casing is formed at the inside portion of the screw holder.

Abstract: A case for holding a magnetic tape cassette has flat locking projections or tabs upright from the inner wall surface thereof to engage the hubs of the magnetic tape cassette and thereby lock the hubs unrotatably. The locking tabs are formed with a step each in the upper part. The step of each said tab is parallel or inclined to the place of the inner wall surface.

Abstract: A tape cassette including a pair of plates having a pair of bent portions each for holding magnetic tape and reel hubs on which the magnetic tape is wound. A plurality of cut portion are formed in each of the bent portions for defining portions facing the reel hubs, such portions projecting toward the reel hubs so as to be in contact with the reel hubs.

Abstract: A magnetic tape cassette including a pressure pad which consists of a pad piece and a leaf spring holding the piece in place, characterized in that the leaf spring is formed, in one piece, of a pad-piece-holding portion supporting the back side of said pad piece, two wing portions and Y-shaped portions extending from the upper and lower edge sections of the both ends of said pad-piece-holding portion and joining said both wing portions is provided. The present pressure pad is capable of exerting a uniform pressure to a magnetic tape against a magnetic recording and reproducing head of a magnetic tape cassette recorder when said cassette is put in position of the recorder and the recorder is placed in the recording or reproducing mode.

Abstract: An improved magnetic tape cassette and separation sheet therefor. The separation sheet, positioned between an inner wall and the tape reels of a cassette, is formed with at least one dome-like protrusion. A plurality of such protrusions are preferably utilized spaced throughout the sheet, each of a diameter R and height H sized to provide an R/H ratio of between about 100 and 10. The separation sheet may be formed with a protrusion shaped to fit into a window in an inner case wall, the window-fitting protrusion extending from a side of said separation sheet opposite from that containing said dome-like protrusions.

Abstract: A tape cassette comprises a supporting arm extending over a magnetic shielding plate, a movable body supported by the supporting arm to be movable forward and backward and a resilient material disposed between the movable body and the supporting arm whereby a head can be inserted along the magnetic shielding plate to improve magnetic shielding effect and magnetic recording and reproducing characteristics.

Abstract: A magnetic tape cassette in which a cassette housing has half cases with aligned, confronting projections on innder surfaces thereof on which a cylindrical guide roll with an axial bore therethrough is supported, has an annular, axially projecting rib on either the guide rolls or the projections so as to prevent any burrs which may be on the guide roll around the axial bore therethrough from coming into contact with the projections, thereby preventing noise which might otherwise be caused by the burrs.