JPH04356779A - Tape cassette - Google Patents

Abstract

PURPOSE:To prevent abrasion of a tape due to contact of an end surface of a sliding sheet with a side surface of the tape wound around a reel hub and dirt due to magnetic powder from progressing respectively. CONSTITUTION:The sheets 7 and 8 arranged as sliding bodies above and below the reel hubs 4 and 5 in a tape cassette are formed to have their side surface shapes in the vertical direction to a line combined between individual centers of the reel hubs 4 and 5 to be curved in approximately circular-arcuate in the direction of positioning the reel hubs 4 and 5 inside a circular arc, while only both end parts of the curved individual sheets 7 and 8 are curved in the direction opposite to the direction of the curve.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette in which a pair of left and right reel hubs are provided with sheets having a slippery function above and below the reel hubs.

0002

[Prior Art] Tape cassettes used in cassette-type tape players, VTRs, and other recording and reproducing devices, such as audio cassettes and video cassettes that store magnetic tape, use reels with flanges. In comparison, so-called disordered tape winding, such as stepped winding, random winding, and umbrella winding of the tape-shaped recording medium wound around the reel hub, is more likely to occur. Therefore, conventionally, a pair of sheets as sliding bodies are arranged above and below a pair of left and right reel hubs that are rotatably held in a housing consisting of an upper half and a lower half. A pair of protrusions are provided, and the protrusions elastically sandwich the reel hub and the tape-shaped recording medium wound around the reel hub from above and below, thereby preventing the tape from becoming irregularly wound.

FIG. 4 is a cross-sectional view showing how the reel hub and sheet are stored in the tape cassette. Reel shafts 51a and 52a are provided in the upper half 51 and lower half 52, respectively, which form the cassette housing. A reel hub 53 is engaged with and held by the shafts 51a and 52a, and a magnetic tape T is wound around the outer periphery of the reel hub 53. Seats 54 and 55 are disposed between the reel hub 53 and the upper half 51 and lower half 52, respectively, and the seats 54 and 55 in the prior art have approximately arc shapes when viewed from the side as shown in the figure. Two protrusions 54a are curved to sandwich the reel hub 53 and the magnetic tape T, and are formed in parallel inside the arc.
, 55a are made to protrude, and these protrusions 54a, 55
The sheets 54 and 55 are arranged so as to come into contact with the reel hub 53 and the magnetic tape, and these sheets 54 and 55 determine the tape running position and the reel hub, thereby preventing the tape from winding irregularly.

0004

[Problem to be solved by the invention] Such a sheet 54
, 55 is curved into a substantially arcuate shape in order to obtain elasticity during clamping, and also to curve the ridges 54a, 55a.
However, on the other hand, the tips of the substantially arc-shaped ends 54b and 55b come into contact with the side surface of the wound magnetic tape T. There is a problem in that fine powder peels off from the magnetic layer of the magnetic tape T and adheres to the ends 54b and 55b of the sheets 54 and 55, accelerating wear of the magnetic tape T, and also because the sheets 54 and 55 are transparent. In the case of a tape cassette that can be viewed through the window of the cassette housing, there is a problem in that the appearance of the tape deteriorates due to the adhesion of magnetic powder on the sheets 54 and 55.

[0005]

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and provides a pair of left and right reel hubs rotatably held in a housing consisting of an upper half and a lower half. In a tape cassette in which sheets as a body are arranged, each sheet has a side surface shape perpendicular to a line connecting the centers of a pair of reel hubs that is curved into a substantially arc shape in a direction in which the reel hubs are located inside the arc. At the same time, only both curved end portions of each sheet are curved in opposite directions so that the tips of the both end portions do not come into contact with the tape-shaped recording medium wound around the pair of reel hubs. It is something.

[0006]

[Operation] By bending the end of the sheet, which is curved into a generally circular arc with the reel hub and tape inside, in the opposite direction to the curved direction of the arc, the sheet end surface will come into contact with the side surface of the wound tape. This prevents accelerated wear and damage to the tape.

[0007]

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. 1(a) and 1(b) are a plan view and a side view of a sheet applied to the tape cassette of this embodiment, FIG. 2 is an exploded perspective view showing the structure of the tape cassette, and FIG. 3 is a tape showing the stored state of the sheet. FIG. 3 is a partial cross-sectional view of the cassette. In these figures, 1 indicates the tape cassette as a whole, 2
, 3 are upper and lower halves forming a tape cassette housing; 4 and 5 are reel hubs rotatably supported within the tape cassette housing; 6 are magnetic tapes wound around the reel hubs 4 and 5; 7 and 8 are magnetic tapes wound around the reel hubs 4 and 5; A sheet with a slippery effect is shown.

As shown in FIG. 2, a tape cassette 1
The housing is formed by integrating upper and lower halves 2 and 3, which are molded from synthetic resin such as polystyrene, with screws 16. Reel shafts 2a and 3a projecting in a ring shape are provided on the inner surfaces of the upper and lower halves 2 and 3, and the reel shafts 2
Reel hubs 4, 5 with magnetic tape 6 wound around a, 3a
The reel hubs 4 and 5 are engaged with each other to be rotatably supported, and seats 7 and 8 are interposed in the gaps between the reel hubs 4 and 5 and the upper and lower halves 2 and 3, respectively. A pair of left and right tape guide rollers 9, 10 and tape guide pins 11, 12 are provided as guide members for the magnetic tape 6, and a magnetic shield plate 13, usually made of a permalloy plate or the like, is provided at the front center of the tape cassette housing. A leaf spring 15 fitted into the magnetic shield plate 13 and having a tape pad 14 made of felt or the like attached thereto is supported on the front part of the magnetic shield plate 13. In addition, reel insertion holes 2b and 3b formed in the center of the upper and lower halves 2 and 3
There are rectangular windows 2c and 3c around the area for checking the amount of tape.
For example, it is molded from transparent resin by two-color molding. Further, on the inner surfaces of the upper and lower halves 2 and 3, pins 3d1 and 3d2 (the pins 2d1 and 2d2 of the upper half 2 are not shown) are provided as positioning members for the sheets 7 and 8.

The sheets 7 and 8 stored in this tape cassette 1 are formed into transparent films having a thickness of, for example, about 38 μm, and as shown in FIG. Holes 7a, 8a are formed corresponding to the shafts 2a, 3a, and the reel shafts 2a, 3a are inserted therethrough. Furthermore, notches 7b and 8b are formed corresponding to and engaging with the pins 2d1 and 3d1. Furthermore, the hole 7a
, 8a, and two protrusions 7c in a state substantially parallel to the line connecting the centers of 8a.
, 8c are formed, and the sheets 7, 8 are generally provided with protrusions 7c, 8 as shown in the side view of FIG. 1(b).
It is curved into a substantially arc shape with c being the inner side of the arc, but only the ends 7d and 8d are slightly curved in the opposite direction to the curve direction of the arc.

The storage state of the reel hubs 4, 5 and sheets 7, 8 in the tape cassette of this embodiment is as shown in FIG.
, 8 are interposed between the reel hubs 4, 5 and the upper and lower halves 2, 3, and sandwich the reel hubs 4, 5 and the magnetic tape 6. In particular, by sandwiching them on the inside of the arc shape, a good By obtaining elastic force and having the protrusions 7c, 8c properly contact the reel hubs 4, 5 and the magnetic tape 6, the magnetic tape 6 and the reel hubs 4, 5 can be effectively positioned during running, and the sheet 7, 8, the reel hubs 4, 5, and the magnetic tape 6 are mainly contacted by the protrusions 7c, 8.
Since this is done by line contact at the top of the reel hubs 4 and 5, loss torque during rotation of the reel hubs 4 and 5 does not increase due to the influence of the sheets 7 and 8, and there is almost no sliding noise.

Furthermore, the ends 7d, 8 of the sheets 7, 8
Only d goes towards the upper and lower halves 2 and 3, respectively.
In other words, since it is curved in the direction away from the magnetic tape 6, the tip portions 7d1, 8 of the ends 7d, 8d
d1 does not come into contact with the magnetic tape 6, and the end 7d
, 8d only smoothly contact the curved surfaces 7d2, 8d2, so that the tip portions 7d1, 8d of the ends 7d, 8d
8d1 prevents the magnetic tape 6 from being severely worn and almost no magnetic powder falls off. Therefore, the accelerated wear of the magnetic tape 6 is eliminated, and the appearance is not spoiled due to magnetic powder adhering to the sheets 7 and 8, which is visible through the windows 2c and 3c.

The shape of the slippery sheet in the tape cassette of the present invention is not limited to the shape shown in FIG. 1, but can be changed as appropriate depending on the shape and form of the tape cassette to which it is applied.

[0013]

Effects of the Invention As explained above, in the tape cassette of the present invention, the end of the sheet having a slippery action does not come into contact with the tape at its tip, so the tape cassette can be operated without accelerating wear of the tape. This has the effect that the tape and reel hub can be positioned, and the sheet itself is hardly contaminated with magnetic powder, etc., and the appearance of the tape cassette is prevented from deteriorating.

[Brief explanation of drawings]

FIG. 1 is a plan view and a side view of a sheet in one embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the structure of the tape cassette of this embodiment.

FIG. 3 is a partial sectional view showing a state in which the sheet and reel hub of the tape cassette of this embodiment are stored.

FIG. 4 is a partial sectional view showing a state in which the sheet and reel hub of the tape cassette in the prior art are stored.

[Explanation of symbols]

1 Tape cassette 2 Upper half 3 Lower half 4,5 Reel hub 6 Magnetic tape 7, 8 sheets 7c, 8c Convex strip 7d, 8d End 7d1, 8d1 Tip part

Claims (1)

[Claims] 1. A tape cassette in which sheets as sliding bodies are disposed above and below a pair of left and right reel hubs that are rotatably held in a housing consisting of an upper half and a lower half, wherein each of the sheets The side surface shape in the direction perpendicular to the line connecting each center of the reel hub is curved into a substantially arc shape in the direction in which the reel hub is located inside the arc, and only the curved end portions of each sheet are in the opposite direction. A tape cassette characterized by being curved.