JPH0510309Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a tape reel for a magnetic tape cassette used in a video tape recorder (VTR), and in particular includes a three-piece reel body and one guide flange. The present invention relates to a mounting structure for a pivot that constitutes a reel.

[Conventional technology]

Conventional tape reels used in VTR magnetic tape cassettes are generally as shown in Figure 4.
It is composed of three pieces: a reel body 3 in which a reel hub 1 and a lower guide flange 2 are integrally formed, an upper guide flange 4 and a pivot 5, of which the pivot 5 is connected to the through hole 4 of the upper guide flange 4.
a protrusion 5a that protrudes upward from a and is pressed by a reel holding spring fixed to the inner surface of the cassette body;
and a cylindrical base 5b that is fitted into the fitting hole 6 formed in the center of the upper surface of the reel hub 1. The pivot 5 is fitted into the fitting hole 6 of the reel hub 1 when assembling the three pieces. While still fitted, they are placed on a conveyor and transported to each process.

[Problem that the invention attempts to solve]

However, the shape of the pivot and the fitting hole described above makes it difficult to fit the pivot, and if the pivot pops out of the fitting hole due to vibration during conveyor transportation, it must be manually refitted. Workability was poor.

The present invention was developed against the background of the above circumstances, and an object of the present invention is to provide a tape reel for a magnetic tape cassette in which the pivot can be easily fitted into the fitting hole and the fitted state can be maintained even under vibration.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention forms a fitting hole on the upper surface of the reel hub that serves as the winding core of the magnetic tape, and presses a reel holding spring fixed to the inner surface of the cassette body into the fitting hole. In a tape reel of a magnetic tape cassette fitted with a pivot, the inner peripheral surface of the fitting hole is formed into a tapered surface with a tapered bottom, and the outer periphery of the base of the pivot fitted in the fitting hole is formed. The device is characterized in that a tapered surface having the same slope as the fitting hole portion is formed.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

The magnetic tape cassette 10 has a cassette main body 13 consisting of an upper half 11 and a lower half 12, and tape reels 15, 15 for supplying and winding the magnetic tape 14 on the inner surface of the upper half 11. It is pressed and held toward the lower half 12 side by a fixed reel holding spring 16, and the front part of the cassette main body 13 has a magnetic tape that is unwound from both reels 15, 15 and runs on the front surface of the tape guide parts 13a, 13a. A front lid 17 covering the tape 14 is attached so as to be openable and closable.

Each of the tape reels 15, 15 is made of a synthetic resin material and has the same shape.
8 and a lower guide flange 19 that supports the lower edge of the tape 14 are integrally formed;
This is a three-piece reel consisting of an upper guide flange 21 and a pivot 22 provided on the upper part of the reel hub 18. The pivot 22, which is pressed by the reel restraining spring 16, has better wear resistance than the reel body 20 and the upper guide flange 21. Made of superior hard synthetic resin material.

The reel hub 18 has a plurality of engagement ribs 23a.
Inner peripheral wall 18a having a reel hole 23 protruding from
and an outer peripheral wall 18b that becomes the winding core of the magnetic tape 14.
A fitting hole 26 into which the pivot 22 is fitted is formed in a fitting protrusion 25 protruding from the upper surface 24 of the inner circumferential wall 18a, and the reel hub 18
The lower guide flange 19 provided at the lower end of the
A guide edge 19a for guiding the reel shaft of the VTR into the reel hole 23 and an engaging edge 19b loosely fitted into the mounting hole of the cassette body 13 are provided to protrude inwardly and outwardly.

Further, the upper guide flange 21 has a flange portion 21
A through-hole 21c and a fitting recess 27 opening on the lower surface are continuously formed in the center of a protrusion 21b protruding from the lower part of a, and the protrusion 21b on the outer periphery of the fitting recess 27 has
A plurality of welding protrusions 28 are protrudingly provided to be welded to the upper surface 24 of the reel hub 18.

This fitting recess 27 is fitted into the fitting protrusion 25 of the reel hub 18 when the upper guide flange 21 is assembled to the reel main body 20. is formed into a tapered surface that widens toward the opening side, and the fitting protrusion 25 is also formed into a trapezoid with an outer circumferential surface 25a that is a tapered surface having the same slope as the outer circumferential surface 25a.
The upper guide flange 21 can be assembled and aligned quickly and easily.

Further, the pivot 22 is connected to the upper guide flange 2.
A projection 22a protruding upward from the through hole 21c of No. 1
and an inverted trapezoidal base 22b that is fitted into the fitting hole 26 of the reel hub 18, and the fitting hole 26 has an inner circumferential surface 26a formed into a tapered surface that narrows at the bottom. together with the base 22b of the pivot 22.
The outer circumferential surface 22c is also formed into an inverted trapezoid with a tapered surface having the same slope.

As described above, in this embodiment, the inner circumferential surface 26a of the fitting hole 26 of the reel hub 18, and the outer circumferential surface 22c of the base 22b of the pivot 22 fitted into the hole 26.
and have tapered surfaces, the pivot 22 can be assembled and aligned quickly and easily, and the reel body 2 with the pivot 22 fitted can be quickly and easily assembled.
Even if the pivot 22 comes off from the fitting hole 26 due to vibration when conveying the pivot 22 on the conveyor, it can be returned to its original position naturally due to the tapered shape of both circumferential surfaces 22c and 26a. Therefore, workability is not impaired.

FIG. 3 shows another embodiment of the present invention, in which the pivot 29 has a base 29b protruding from a protrusion 29a.
, the upper cylindrical part 29c and the lower inverted trapezoidal part 29d.
The outer circumferential surface 29e of the inverted trapezoidal portion 29d is formed by
It is formed into a tapered surface having the same slope as the inner circumferential surface 26a of the fitting hole portion 26, and this embodiment also produces the same effects as the above embodiment.

As described above, according to both of the above embodiments, the fitting to the upper surface of the reel main body is guided by the tapered surface, and the ease of assembling the pivot is improved.
Since the upper guide flange can be easily fitted to the upper surface of the reel body by the guide of the tapered surface, the workability of assembling the three pieces can be further improved.

[Effect of idea]

As explained above, the tape reel of this invention has
The inner circumferential surface of the fitting hole on the top surface of the reel hub is formed into a tapered surface with a tapered bottom, and the outer periphery of the base of the pivot to be fitted into the fitting hole is formed with a tapered surface having the same slope as the fitting hole. Because of this shape, the pivot can be quickly and easily assembled and aligned by guiding on both circumferential surfaces, and when the reel body with the pivot fitted is transported on a belt conveyor, etc., the pivot can be positioned in the fitting hole. Even if it starts to come off due to vibration, it will return to its original position naturally without any manual effort, allowing for smooth work.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, in which FIG. 1 is a cross-sectional front view of a tape reel, and FIG.
The figure is a partially cutaway plan view of a magnetic tape cassette for a VTR, FIG. 3 is an enlarged sectional view of the main part of a tape reel showing another embodiment, and FIG. 4 is a sectional front view of a conventional tape reel. DESCRIPTION OF SYMBOLS 10... Magnetic tape cassette, 13... Cassette body, 14... Magnetic tape, 15... Tape reel, 18... Reel hub, 20... Reel body, 21... Upper guide flange, 22... Pivot, 22a... ...Protrusion, 22b...Base, 22c...
...outer circumferential surface, 25...fitting protrusion, 25a...outer circumferential surface, 26...fitting hole, 26a...inner circumferential surface, 27
...Fitting recess, 27a...Inner peripheral surface, 28...Protrusion for welding.

Claims (1)

[Scope of utility model registration request] A tape of a magnetic tape cassette in which a fitting hole is formed on the upper surface of a reel hub that serves as a winding core of the magnetic tape, and a pivot that is pressed by a reel holding spring fixed to the inner surface of the cassette body is fitted into the fitting hole. In the reel, the inner circumferential surface of the fitting hole is formed into a tapered surface with a tapered bottom, and the outer periphery of the base of the pivot to be fitted into the fitting hole is formed with a tapered surface having the same slope as the fitting hole. A tape reel for a magnetic tape cassette, characterized in that it has a magnetic tape cassette.