JPH0632191B2 - Tape reel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape reel used in, for example, a tape cassette for a video tape recorder, and a synthetic resin tape reel having upper and lower flanges provided at both upper and lower ends of a hub.

[0002]

2. Description of the Related Art A conventional example of a tape reel used in a tape cassette for a video tape recorder will be described with reference to FIGS.

In this conventional example, a hub 1 and a lower flange 2 provided at the lower end of the hub 1 are integrally molded of synthetic resin,
The hub 1 is provided with an inner cylindrical portion 4 whose inside is formed in the reel shaft insertion hole 3 and an outer cylindrical portion 6 whose outer peripheral surface is formed on the tape winding surface 5, and which is made of synthetic resin.
Is welded to the upper end surface 4a of the inner cylindrical portion 4 of the hub 1. Reference numeral 8 denotes a large number of reel claws provided on the inner peripheral surface of the reel shaft insertion hole 3.

By the way, in this type of tape reel, after the upper flange 7 is welded to the hub 1, the clamp piece 9 is
To the hub 1 from the driving opening 10 provided on the upper flange 7.
5, the end 12a of the magnetic tape 12 is locked by the clamp piece 9 in the clamp piece locking groove 11 provided in the outer cylindrical portion 6 from the direction of arrow a in FIG. . Therefore, when welding the upper flange 7 to the hub 1, it is necessary to accurately position the driving opening 10 directly above the clamp piece locking groove 11. Further, as a matter of course, the upper flange 7 needs to be properly welded to the hub 1 in the same axial line state.

Therefore, in this type of tape reel, the upper flange 7 must be welded to the hub 1 in a properly positioned state both in the radial direction and in the circumferential direction.

[0006]

The tape reel shown in the prior application example (Actual Application No. 58-129482) filed earlier by the applicant of the present invention is the ceiling plate at the upper end of the inner cylindrical portion of the hub. Since it is a closed structure, a plurality of dowels are integrally formed and provided on the ceiling plate, and a plurality of dowel holes provided in the upper flange are engaged with the dowels, whereby the upper flange of the hub is Both the radial direction and the circumferential direction can be easily positioned.

However, in the conventional example shown in FIGS. 5 and 6, the upper end of the inner cylindrical portion 4 of the hub 1 is open,
Upper end surface 4a of the inner cylindrical portion 4 having a very small welding area
Has a structure in which the upper flange 7 must be welded to
A plurality of dowels as shown in the above-mentioned prior application cannot be integrally formed and provided on the upper end surface 4a having a very small welding area. In FIG. 6, the outer peripheral surface 13a of the downward circular bulging portion 13 provided in the central portion of the lower surface of the upper flange 7 is press-fitted into the inner peripheral surface 6a of the outer cylindrical portion 6 without rattling, and the hub 1 Although a method of positioning the upper flange 7 in the radial direction with respect to the tape is also conceivable, such a structure causes distortion in the roundness of the tape winding surface 5 which is the outer peripheral surface of the outer cylindrical portion 6, and the tape Wrinkles occur on the magnetic tape 12 wound around the winding surface 5. Therefore, the outer peripheral surface 1
A gap 14 must be provided between 3a and the inner peripheral surface 6a, and the outer cylindrical portion 6 cannot position the upper flange 7.

The present invention makes it possible to perform both radial and circumferential positioning of the upper flange with respect to the hub by utilizing the outer peripheral surface of the inner cylindrical portion of the hub.

[0009]

According to the present invention, in a tape reel as shown in FIGS. 5 and 6, a recess is provided on the outer peripheral surface of the inner cylindrical portion of the hub, and a flat shape is formed on the lower surface of the upper flange. A rib having a C-shape is integrally formed, and a pair of locking portions projecting inward of the rib are provided at the opening end of the rib, and the upper flange is placed on the inner cylindrical portion of the hub. When the ribs are mounted on the end faces, the ribs are fitted to the outer peripheral surface of the inner cylindrical portion and the pair of locking portions are locked in the recesses.

[0010]

According to the present invention, the outer peripheral surface of the inner cylindrical portion of the hub can be utilized to accurately and reliably position the upper flange with respect to the hub in both the radial direction and the circumferential direction. No distortion occurs in the roundness of the tape winding surface, which is the outer peripheral surface of the outer cylindrical portion.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tape reel used in a tape cassette for a video tape recorder according to the present invention will be described below with reference to FIGS. It should be noted that the same structural parts as those of the conventional example described with reference to FIGS.

First, according to the present invention, as described above, the clamp piece locking groove is provided at a position facing the clamp piece locking groove 11 on the outer peripheral surface 4b of the inner cylindrical portion 4 of the hub 1 formed of synthetic resin. A recess 16 having a wider width in the circumferential direction than 11 is provided. On the other hand, as described above, the rib 17 having a substantially C-shaped plane is integrally formed along the peripheral portion of the lower surface of the circular bulge 13 at the center of the upper flange 7 made of synthetic resin. There is. Further, a pair of locking portions 18 projecting to the inside of the rib 17 are provided at the opening end of the rib 17, and the pair of locking portions 18 are used for driving the clamp piece as shown by a chain line in FIG. The openings 10 are arranged at equal intervals on both sides in the circumferential direction with respect to the opening 10.

According to the present invention, as shown in FIGS. 3 and 4, when the upper flange 7 is placed on the upper end surface 4a of the inner cylindrical portion 4 of the hub 1 by the circular bulging portion 13 at the center thereof, as shown in FIG. As shown in FIG. 2, the rib 17 is fitted to the outer peripheral surface 4b of the inner cylindrical portion 4 without rattling, and
As shown in FIG. 5, the pair of locking portions 18 are locked to both end surfaces 16a of the recess 16 in the circumferential direction without rattling. As a result, the upper flange 7 is correctly positioned in both the radial direction and the circumferential direction with respect to the hub 1, the upper flange 7 is accurately positioned in the same axial state with respect to the hub 1, and the clamp piece is driven. The opening 10 for use is accurately positioned right above the clamp piece locking groove 11.

According to the present invention, as described above, the outer peripheral surface 4b of the inner cylindrical portion 4 of the hub 1 is utilized to position both the radial direction and the circumferential direction of the upper flange 7 with respect to the hub 1. 1, the outer peripheral surface 13a of the circular bulging portion 13 of the upper flange 7 and the inner peripheral surface 6 of the outer cylindrical portion 6 of the hub 1 as shown in FIG.
Since the gap 14 can be provided between the tape and a, as in the conventional example, the circularity of the tape winding surface 5, which is the outer peripheral surface thereof, is not distorted at all.

In the state of positioning as described above,
As shown in FIG. 1, the welding horn 20 is pressed against a plurality of locations around the circular bulging portion 13 of the upper flange 7, and the upper flange 7 is attached to the upper end surface 4a of the inner cylindrical portion 4 of the hub 1 as in the conventional example. Similarly, welding (ultrasonic welding) is performed.

In the embodiment of the present invention, FIGS.
As shown in FIG. 2, a plurality of reinforcing ribs 21 that connect the outer peripheral surface 4b of the inner cylindrical portion 4 of the hub 1 and the inner peripheral surface 6a of the outer cylindrical portion 6 are integrally formed and provided. The rib 17 of the upper flange 7 is provided with a plurality of slits 22 that are fitted to the plurality of reinforcing ribs 21. The upper flange 7 for the hub 1 is engaged with the reinforcing ribs 21 and the slits 22. The circumferential positioning force of is further increased.

Further, in the embodiment of the present invention, FIGS.
As shown in FIG. 3, an annular step portion 23 is provided on the inner peripheral edge of the upper end surface 4 a of the inner cylindrical portion 4 of the hub 1, and an outer peripheral edge 24 a of a metal plate 24 made of a stainless steel disc or the like is horizontally arranged in the annular step portion 23. , The upper flange 7 is welded to the upper end surface 4a of the inner cylindrical portion 4 as described above, and the circular bulge portion 13 of the upper flange 7 presses the metal plate 24 from above to form a hub. It is stuck to 1. A circular opening 25 is provided in the center of the circular bulging portion 13.

When the tape reel constructed as in this embodiment is assembled in a tape cassette for a video tape recorder, it is attached to the upper half 32 of the tape cassette 31 as shown by the chain line in FIG. A semi-spherical convex portion 34a integrally provided on the central lower surface of a synthetic resin reel retainer 34 that is pressed downward by a compression coil spring 33 is provided in the central opening 25 of the upper flange 7 with a metal plate 24. It comes to be pressed on the central upper surface of. By the pressing of the reel retainer 34, the lower flange 2 is moved to the lower half 3
5, the lower half 35 is provided with an annular convex portion 36 for mounting on the reel stand, which is pressed onto the reel shaft 5 and is integrally formed on the lower surface of the lower flange 2 at the outer periphery of the reel shaft insertion hole 3. It is fitted into the insertion hole 37.

When the tape cassette is used, the reel shaft (not shown) of the reel base inserted into the reel base insertion hole 37 from below is inserted into the reel shaft insertion hole 3 and engaged therewith. At the same time, the entire tape reel is rotationally driven by the reel stand while being lifted against the compression coil spring 33 by the reel stand.
Since the convex portion 34a of the synthetic resin reel retainer 34 can be pressed against the central upper surface of the metal plate 24 having high abrasion resistance, the abrasion of the metal plate 24 due to the rotation of the tape reel can be prevented. The tape reel has high durability and reliability.

That is, in the conventional tape reel shown in FIG. 6, the convex portion 34a of the reel retainer 34 is pressed against the central upper surface of the circular bulging portion 13 formed integrally with the upper flange 7. Since the synthetic resins come into contact with each other, the central upper surface of the circular bulging portion 13 is likely to be quickly worn away by the rotation of the tape reel.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various effective modifications can be made based on the technical idea of the present invention.

The present invention is not limited to tape reels used in tape cassettes for video tape recorders, but can be applied to various reels for winding various tapes and films.

[0023]

According to the present invention, the roundness of the tape winding surface, which is the outer peripheral surface of the outer cylindrical portion of the hub, is not distorted.
The upper flange can be accurately and reliably positioned with respect to the hub in both the radial direction and the circumferential direction.

[0024]

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of a tape reel according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the main part shown in FIG.

3 is a vertical cross-sectional view of the entire tape reel shown in FIG.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is an exploded perspective view of a conventional tape reel.

6 is a vertical cross-sectional view of the entire tape reel shown in FIG.

[Explanation of symbols]

 1 Hub 2 Lower Flange 3 Reel Shaft Insertion Hole 4 Inner Cylindrical Part 4a Upper End Surface of Inner Cylindrical Part 4b Outer Surface of Inner Cylindrical Part 5 Tape Winding Surface 6 Outer Cylindrical Part 7 Upper Flange 16 Recess 17 Rib 18 Locking Part

Claims (1)

[Claims] 1. A hub and a lower flange provided at the lower end of the hub are integrally molded with a synthetic resin, and the hub has an inner cylindrical portion whose inside is formed in a reel shaft insertion hole and an outer peripheral surface of which is a tape winding surface. A tape cassette in which an outer cylindrical portion formed on the inner cylindrical portion of the hub is welded to an upper end surface of the inner cylindrical portion of the hub by forming a recess on the outer peripheral surface of the inner cylindrical portion of the hub. A rib having a substantially C-shape is integrally formed on the lower surface of the upper flange, and a pair of locking portions projecting inward of the rib is provided at the opening end of the rib. When the rib is mounted on the upper end surface of the inner cylindrical portion of the hub, the rib is fitted on the outer peripheral surface of the inner cylindrical portion and the pair of locking portions are locked in the recess. Tape reel.