JPH0519901Y2 - - 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), etc., and in particular has a pivot member and an upper guide flange at the upper part of the central tube. Regarding the structure for assembling.

[Conventional technology]

Tape reels for magnetic tape cassettes used in VTRs and the like are of the so-called two-piece type, consisting of an upper guide flange and a lower guide flange having a pivot portion integrally formed in the upper center of a central tube. On the other hand, the entire upper guide flange and lower guide flange of the tape reel are usually molded from synthetic resin, but since there is no need to take wear resistance into consideration that much, synthetic resin with particularly excellent wear resistance is not used. Therefore, even if the pivot portion is damaged by wear or the like due to rotation of the tape reel, there is no guarantee.

Therefore, a so-called three-piece type is known, in which a pivot member made of a different material with high wear resistance is separately molded from the lower guide flange, and the pivot member is fitted into the center of the upper part of the central cylinder of the lower guide flange. It is being That is, as shown in FIG. 7, this type of tape reel 1 consists of three pieces: an upper guide flange 2, a lower guide flange 3, and a pivot member 4. The lower guide flange 3 has a tape deck drive shaft ( (not shown) engages, a reel hub 6 for tape winding disposed concentrically with the central cylinder 5 on the outside of the cylinder 5, and a plurality of reel hubs 6 connecting the central cylinder 5 and the reel hubs 6. A connecting rib 7 is integrally molded with the lower guide flange 3, and a fitting part 8 for fitting the pivot member 4 into the center of the upper part of the central cylinder 5, and a fitting part 8 of the upper guide flange 2 on the outside of the fitting part 8 are formed integrally with the lower guide flange 3. An annular fitting groove 9 into which an annular engaging protrusion 2a formed on the lower surface is fitted is formed. Further, the diameter of the reel hub 6 and the length of the connecting rib 7 are changed for long-time and short-time use.

The pivot member 4 is assembled by fitting its lower part into a fitting part 8 formed at the center of the upper surface of the central cylinder 5, and the upper guide flange 2 is assembled by fitting the lower part into a fitting part 8 formed at the center of the upper surface of the central cylinder 5. The edge 2a is fitted into the fitting groove 9 of the central cylinder 5, and the welding protrusion 2b protruding from the outer peripheral side of the engaging protrusion 2a is ultrasonically welded to the upper surface of the central cylinder 5, and assembled. A tape reel 1 is manufactured.

[Problem that the invention attempts to solve]

However, in the above-described structure, the tips of the lower outer edge of the pivot member 4, the opening edge of the fitting part 8, the lower edge of the engaging protrusion 2a of the upper guide flange 2, and the opening edge of the fitting groove 9 are Since the tape reel 1 is formed at a substantially right angle, alignment during fitting is troublesome, and a slight positional deviation makes assembly impossible, resulting in poor workability in assembling the tape reel 1.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tape reel for a magnetic tape cassette in which an upper guide flange and a pivot member can be easily assembled to a lower guide flange.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention has a fitting portion that fits the pivot member into the upper part of the central cylinder of the tape reel, and a fitting portion that fits the engaging protrusion formed on the lower surface of the upper guide flange. In the tape reel of the magnetic tape cassette in which a mating groove is formed, at least one of the lower outer edge of the pivot member and the opening edge of the fitting part, and the lower edge of the engaging protrusion of the upper guide flange and the fitting part. The groove is characterized in that a guide slope portion is formed on at least one of the opening edges of the groove.

[Effect]

Therefore, when assembling the upper guide flange and the pivot member to the lower guide flange, both parts can be guided to a predetermined position in the central cylinder of the lower guide flange by the respective guide slopes, and the assembly and centering of these parts can be easily performed. Alignment can be performed quickly and easily, and tape reel assembly work efficiency is improved.

〔Example〕

Hereinafter, a first embodiment of the present invention will be described based on FIGS. 1 and 2.

The magnetic tape cassette 20 rotatably houses two tape reels 25, 25 for supplying and winding a magnetic tape 24 in a cassette body 23 consisting of an upper half 21 and a lower half 22. A magnetic tape 24 is wound around the front surface of the cassette main body 23, and a front cover 23a is attached to the front portion of the cassette body 23 so as to be openable and closable.

The tape reel 25 has a through hole 26a in the center.
an upper guide flange 26 having
7. Reel hub 28 disposed concentrically with the central cylinder 27 and outside the cylinder 27; central cylinder 27 and reel hub 2;
A lower guide flange 30 integrally formed with a plurality of connecting ribs 29 connecting the upper half 21 and the tape reel 25 protrudes upward from the through hole 26a.
A plate-shaped reel suppressing spring 31 interposed between
It is composed of three pieces including a pivot member 32 which is pressed at the tip of the pivot member 32. An annular peripheral wall 33 is erected at the upper part of the central cylinder 27 of the lower guide flange 30, and the inside of the peripheral wall 33 is connected to a pivot member 32.
A fitting groove 35 for attaching the upper guide flange 26 is formed on the outer peripheral side of the peripheral wall 33.

The upper guide flange 26 has a circular stepped portion 26b projecting downwardly formed in the center thereof, and a through groove 26a through which the shaft portion of the pivot member 32 is inserted is bored in the center of the stepped portion 26b. A welding protrusion 26c for fixing the flange 26 to the upper part of the central cylinder 27 of the lower guide flange 30 is protrudingly provided on the outer peripheral part of the lower surface of the step part 26b, and a welding protrusion 26c for fixing the flange 26 to the upper part of the central cylinder 27 of the lower guide flange 30 is provided inside the protrusion 26c. An annular engaging protrusion 36 that fits into the fitting groove 35 is formed higher than the welding protrusion 26c.

The lower outer edge of the pivot member 32 that fits when the tape reel 25 is assembled, the upper edge of the inner peripheral side of the peripheral wall 33 that becomes the opening edge of the fitting part 34, and the lower part of the engaging protrusion 36 of the upper guide flange 26. The inner periphery of the edge and the upper edge of the outer periphery of the peripheral wall 33, which is the opening edge of the fitting groove 35, are provided with guide slope portions 32a and 33, respectively.
a, 33b, and 36a are formed.

When assembling the pivot member 32 to the central cylinder 27, both the guide slope portions 33a, 32a are
guides the pivot member 32 to the fitting portion 34, and when assembling the upper guide flange 36, both guide slope portions 36a, 33b guide the upper guide flange 26 to the fitting groove 35, and the pivot member 32
Also, the assembly and alignment of the upper guide flange 26 can be performed quickly and easily.

FIG. 3 shows a second embodiment of the present invention, in which the central cylinder 2
A fitting part 34 and a fitting groove 35 formed on the upper surface of 7
No guide slope is formed on the peripheral wall 33 that forms both opening edges, but on the inner periphery of the lower outer edge of the pivot member 32 and the lower edge of the engaging protrusion 36 of the upper guide flange 26,
Guide slope portions 32a, 3 similar to the first embodiment
6a, respectively.

FIG. 4 shows a third embodiment of the present invention.
Contrary to the embodiment, the lower outer edge of the pivot member 32 and the engaging protrusion 36 of the upper guide flange 26 are not provided with a guide slope portion, but the fitting portion 34 and the fitting groove 3 are formed.
On both upper edges of the inner and outer peripheries of the peripheral wall 33, which are the opening edges of 5,
Guide slope portions 33a, 3 similar to the first embodiment
3b, respectively.

FIG. 5 shows a fourth embodiment of the present invention, in which the fitting part 3
Guide slopes 33a and 36a are formed on the inner circumferential side edge of the peripheral wall 33, which serves as the opening edge of No. 4, and on the inner circumference of the lower edge of the engaging protrusion 36 of the upper guide flange 26, respectively.

FIG. 6 shows a fifth embodiment of the present invention, in which the fitting groove 3
Guide slope portions 33b, 3 are provided at the outer peripheral side upper edge of the peripheral wall 33 and the lower outer edge of the pivot member 32, which are the opening edges of the pivot member 32.
2a, respectively.

In each of the embodiments shown in FIGS. 3 to 6 above,
Since the guide slope portion is provided only on one of the pivot member 32 and the fitting portion 34, and the engaging protrusion 36 and the fitting groove 35, these embodiments can also achieve sufficient effects.

As shown in each of the above embodiments, the present invention has a feature that, when the pivot member and upper guide flange are assembled from above onto the central tube of the lower guide flange, the respective guide slopes can guide the pivot member and the upper guide flange to a predetermined position on the central tube, making it possible to quickly and easily assemble and align each component and improving the efficiency of tape reel assembly.

[Effects of the invention] As explained above, the present invention provides a tape reel for a magnetic tape cassette in which a pivot and an upper guide flange are fixed to the upper part of the central cylinder of the lower guide flange. A guide slope is provided on at least one of the opening edges of the fitting portion to be fitted, and at least one of the lower edge of the engagement protrusion of the upper guide flange and the opening edge of the fitting groove into which the engagement protrusion is fitted. Since the pivot member and the upper guide flange can be guided to predetermined positions in the center cylinder of the lower guide flange, assembly and alignment can be performed quickly and easily, and the tape reel assembly work efficiency can be improved.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a sectional view of a main part of a tape reel, FIG. 2 is a partially cutaway plan view of a magnetic tape cassette, and FIG. FIG. 4 is a cross-sectional view of the main part of a tape reel showing the second embodiment of the present invention. FIG. 5 is a cross-sectional view of the main part of the tape reel showing the third embodiment of the invention. A cross-sectional view of the main parts of the tape reel shown in Fig. 6.
The figure is a sectional view of a main part of a tape reel showing a fifth embodiment of the present invention, and FIG. 7 is a sectional view of a main part of a tape reel showing a conventional example. 20... Magnetic tape cassette, 25... Tape reel, 26... Upper guide flange, 27...
Central tube, 28... Reel hub, 30... Lower guide flange, 32... Pivot member, 33... Peripheral wall, 34... Fitting portion, 35... Fitting groove, 36...
Engagement protrusion, 32a, 33a, 33b, 36a...
Guide slope section.

Claims (1)

[Scope of utility model registration request] In a tape reel of a magnetic tape cassette, a fitting part for fitting a pivot member in the upper part of a central cylinder of the tape reel and a fitting groove for fitting an engaging protrusion formed on the lower surface of an upper guide flange are formed. ,
A guide slope portion is provided on at least one of the lower outer edge of the pivot member and the opening edge of the fitting portion, and at least one of the lower edge of the engaging protrusion of the upper guide flange and the opening edge of the fitting groove. A tape reel of a magnetic tape cassette characterized in that each of the tape reels is formed of a magnetic tape cassette.