JPH07130125A - Reel of tape cassette - Google Patents

Abstract

PURPOSE:To prevent the upper part of a hub from shrinking in diameter smaller than the lower part due to winding pressure at the time of winding a magnetic tape. CONSTITUTION:The reel 1 for the tape cassette is composed of the hub 2 and upper and lower flanges 3 and 4 disposed in the upper and lower parts of the hub 2. The hub 2 is composed of an outer cylinder part 2a ad an inner cylinder part 2b disposed on the in side of the outer cylinder part 2a. The upper and lower ends of this inner cylinder part 2b are combined with the upper and lower flanges 3 and 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reel used for supplying or taking up magnetic tape in a tape cassette such as a video tape cassette.

[0002]

2. Description of the Related Art FIG.
The one shown in FIG. 5 is known.

This reel 101 has a cylindrical plastic hub 102, and disk-shaped plastic upper and lower flanges 103 arranged above and below the hub 102.
And 104.

The hub 102 has a three-layer structure including an outer cylinder portion 102a, an inner cylinder portion 102b, and an innermost cylinder portion 102c.

The outer cylinder portion 102a is connected to the inner cylinder portion 102b via first radial ribs 102d ... 102d provided on the inner circumference thereof. In addition, the inner cylindrical portion 102b
Is the second radial ribs 102e ... 1 provided on the inner circumference of the ribs.
It is connected to the innermost tubular portion 102c via 02e.

The hub 102 has the lower flange 1
04 integrally molded with plastic, and the outer cylindrical portion 102
a, the inner tubular portion 102b, the innermost tubular portion 102c, and the lower portions of the first and second ribs 102d ... 102d, 102e ... 102e are integrally joined to the lower flange 104.

102f are provided on the upper ends of the second ribs 102e ... 102e, and the coupling projections 102f ... 102f are inserted into the projection insertion holes 102g provided on the upper flange 103, and these projections are inserted. 102f is protruded from the insertion hole 102g, and the caulked portion 1 is melted by, for example, melting the tip.
By forming 02h ... 102h, the upper flange 103 is integrally coupled to the upper portion of the hub 102.

The magnetic tape 105 is wound around the outer circumference of the outer cylinder portion 102a.

[0009]

In the conventional reel 101, as described above, the lower portion of the outer cylindrical portion 102a around which the magnetic tape 105 is wound has a lower flange 104.
However, since the upper part is in a non-bonded state with the upper flange 103, there are the following problems.

(1) When the outer cylinder portion 102a is a so-called straight cylindrical shape as shown in FIG. 4, when the magnetic tape 105 is wound, the winding pressure of the magnetic tape 105 causes
As shown in FIG. 7, the upper side of the outer cylinder portion 102a is compressed to have a small diameter, so that the magnetic tape 105 is deformed, so-called sleeping is generated on the magnetic tape 105, and
Takes damage.

(2) The problem of the above item (1) is that the outer cylindrical portion 1
02a can be eliminated by previously forming the reverse inclination shape (inverse frusto-conical shape) with the upper side widened as shown in FIGS. 6 to 7. It is difficult to wind the magnetic tape on the hub, and it is difficult to control the tilt angle because the tilt angle changes depending on the winding pressure of the magnetic tape.

The present invention solves the above conventional problems and provides a reel of a tape cassette in which only the upper part of the hub is not reduced in diameter by the winding pressure even when the magnetic tape is wound. It was made for the purpose.

[0013]

SUMMARY OF THE INVENTION The present invention is a reel of a tape cassette having a hub and upper and lower flanges arranged above and below the hub. The inner cylinder portion is arranged inside the outer cylinder portion, and the inner cylinder portion is joined to the upper and lower flanges.

[0014]

Since the outer cylinder of the hub is not connected to the upper and lower flanges, the magnetic tape is wound on the outer circumference of the outer cylinder, so that the winding pressure is applied to the outer cylinder. When the outer cylinder is applied, the diameters of the upper and lower portions of the outer cylinder are reduced substantially evenly.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIGS.

Reference numeral 1 is a reel of the tape cassette of the present invention.

The reel 1 is composed of a cylindrical hub 2 and disc-shaped upper and lower flanges 3 and 4 arranged above and below the hub 2.

The hub 2 includes an outer cylinder portion 2a and the outer cylinder portion 2
It has a three-layer structure of an inner cylindrical portion 2b arranged inside a and an innermost cylindrical portion 2c arranged inside the inner cylindrical portion 2b.

The outer cylinder portion 2a has a first portion provided on the inner periphery thereof.
2d are connected to the inner cylindrical portion 2b via radial ribs 2d.

The inner cylindrical portion 2b has innermost cylindrical portions 2c via second radial ribs 2e ... 2e provided on the inner circumference thereof.
Are linked to.

The second ribs 2e ... 2e provided on the inner circumference of the inner cylindrical portion 2b have coupling protrusions 2f ... 2f at the upper and lower ends.

Then, the coupling protrusions 2f ...
It is inserted into the projection insertion holes 3a and 4a provided in the lower flanges 3 and 4, and the coupling projections 2f ...
By protruding the tip of 2f and melting the tip,
By forming the crimped portion (large diameter portion) 2g ... 2g,
The upper and lower flanges 3 and 4 are integrally connected to the upper and lower portions of the second ribs 2e ... 2e.

A tape clamp (not shown) is provided on the outer peripheral surface of the outer cylinder portion 2a, and the leader tape at the tip of the magnetic tape 8 is locked by the tape clamp.

A driven rib is provided on the inner circumference of the innermost cylinder 2c, and a reel drive shaft (reel base) of a tape drive (tape recorder) is provided on the inner circumference of the innermost cylinder 2c. When is inserted, the drive ribs provided on the outer circumference of the reel drive shaft engage with the driven ribs provided on the inner circumference of the innermost tubular portion 2c so that the rotation of the reel drive shaft is transmitted to the reel. It has become.

The reel 1 of the tape cassette according to the embodiment has the above-described structure, and the upper and lower outer cylindrical portions 2a of the hub 2 around which the magnetic tape 8 is wound are the upper and lower flanges 3, 3.
4 is in a non-bonded state.

Therefore, by winding the magnetic tape 8 around the outer tubular portion 2a of the hub 2, even when a wrapping pressure is applied to the outer tubular portion 2a of the hub 2, the outer tubular portion 2a of the hub 2 is pressed from above. The diameter is reduced substantially evenly toward the lower part.

In the embodiment shown in the drawings, the upper and lower ends of the second ribs 2e ... 2e provided on the inner circumference of the inner cylindrical portion 2b are connected to the upper and lower flanges 3 and 4, respectively. Tube 2b
The upper and lower ends thereof may be joined to the upper and lower flanges 3, 4.

Further, the upper and lower ends of the innermost cylindrical portion 2c may be connected to the upper and lower flanges 3, 4.

Further, the outer cylinder portion 2a and the inner cylinder portion 2b of the hub 2 may be formed as separate bodies and fitted to each other.

[0030]

As described above, the reel of the tape cassette according to the present invention is provided on the outer cylinder portion around which the magnetic tape is wound,
Since the lower portion is not connected to the upper and lower flanges and the outer cylinder portion is reduced in diameter substantially uniformly from the upper portion to the lower portion by the winding pressure of the magnetic tape, the following effects are obtained.

(1) It is possible to reliably prevent the occurrence of damage to the magnetic tape, such as the pushing of the magnetic tape caused by the fact that the upper portion of the hub has a smaller diameter than the lower portion due to the winding pressure of the magnetic tape. .

(2) Even if the outer cylinder portion is formed into a straight cylindrical shape without causing the upper portion of the outer cylinder portion to be spread in advance and formed into a reverse slanted shape (reverse frustoconical shape), the occurrence of sleeping and the like is ensured. Can be prevented.

[Brief description of drawings]

FIG. 1 is an exploded cross-sectional view of a reel of the present invention.

FIG. 2 is a sectional view of the reel of the present invention.

FIG. 3 is a cross-sectional view showing a state in which a magnetic tape is wound around the reel of the present invention.

FIG. 4 is a cross-sectional view of a conventional reel.

FIG. 5 is a cross-sectional view showing a state in which a magnetic tape is wound around a conventional reel.

FIG. 6 is a sectional view of another conventional reel.

FIG. 7 is a cross-sectional view showing a state in which a magnetic tape is wound around another conventional reel.

[Explanation of symbols]

 1 ... Reel 2 ... Hub 2a ... Outer cylinder part 2b ... Inner cylinder part 3, 4 ... Upper and lower flanges

Claims (1)

[Claims] 1. A hub, and upper and lower flanges arranged on the upper and lower parts of the hub, wherein the hub has an outer cylinder part and an inner cylinder part arranged inside the outer cylinder part. A reel of a tape cassette, wherein the reel is provided with the inner cylinder portion coupled to the upper and lower flanges.