JPH0636550Y2 - Magnetic tape cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a magnetic tape cassette using a flanged hub for a tape reel.

2. Description of the Related Art Conventionally, a magnetic tape is wound only on a hub or wound on a flanged hub and stored in a cassette case. Generally, a flanged hub is usually used as a tape reel because a magnetic tape cassette for video requires more accurate winding and protection of the magnetic tape than an audio tape cassette. FIG. 6 is a schematic diagram showing a structure around a tape reel of a magnetic tape cassette based on such a VHS (registered trademark) -standard system. In the figure, 10 is a top plate of the upper half, 12 is a bottom plate of the lower half, and the cassette case is composed of these upper and lower halves. A supply side (right side) tape reel 14 and a winding side (left side) tape reel 16 around which a magnetic tape is wound are housed at predetermined positions in this case. These tape reels 14 and 16 are mounted on the drive shaft insertion window holes 18 and 20 provided on the bottom plate 12 with the central portions of the respective lower faces thereof placed on the plates, and the respective upper faces project from the centers thereof. The center bosses 22 and 24 are pressed by the both ends of a leaf spring 26, the center of which is fixed to the inner surface of the top plate 10. In the case of the standard method, both tape reels 14,
The 16 structures are identical. Therefore, the supply tape reel 14
Is shown in detail in FIG. The tape reel 14 on the supply side has a hub 30 integrally formed with a lower flange 28 having teeth on its outer periphery, and an upper flange 32 combined with the hub 30. For this reason, the center boss 22 is provided at the center of the upper surface of the hub 30, and a plurality of, for example, six caulking bosses 34 are arranged at equal intervals on a circle centered on the boss. Also, the upper flange
A through hole into which the center boss 22 and the caulking boss 34 are respectively fitted is formed in the corresponding portion 32 at a corresponding position. At the time of uniting, as shown in Fig. 8, attach the center boss 22 to the upper flange.
Inserted through the center hole 36 of 32, the caulking boss 34 is the corresponding coupling hole
After being fitted into each of the caulking bosses 38, the head portion 39 of each caulking boss 34 is melted and expanded and caulked, and the flange 32 is fixed to the hub 30. The caulking method is adopted by using a resin having high mechanical strength such as polyacetal (POM) for the hub 30, and a polystyrene (PS), AS
This is because the transparent resin such as is used, and the materials of the both are different. Generally, the mechanical strength of transparent resin is slightly inferior. A tape clamp 42 is used to fix the end of the magnetic tape 40 to the hub 30.

Problems to be Solved by the Invention However, in such a caulking method, each caulking boss 34
It is difficult to reliably match the positional accuracy of the melting jig with. Therefore, if the caulking state is bad, the required height difference is not formed between the tip of the center boss 22 and the tip of the caulking boss 34, and the tape reel 14 may move vertically and horizontally within the clearance within the case. Therefore, when the deck is mounted, as shown in FIG. 6, the tape reel 14 floats up in the direction of the arrow, the tip of the spring 26 extends in the direction of the arrow (lower right), and the protruding caulking boss 34 head 39 May come into contact with.
Therefore, when the hub 30 rotates, the hub 30 is scraped to generate shavings, and uneven rotation occurs, which causes problems such as erroneous recording and erroneous reproduction due to dropout. Also, caulking boss 34
Since the head portion 39 can be seen from the transparent window provided on the upper half upper plate 10, the caulking state can be seen at a glance and the appearance quality is deteriorated.

The present invention has been made by paying attention to such a conventional problem, and by improving the fixing structure of the upper flange to the hub, there is no occurrence of erroneous recording, erroneous reproduction, etc., and the magnetic appearance is excellent. It is an object to provide a tape cassette.

Means for Solving the Problems Means for achieving the above object will be described below with reference to FIGS. 1 and 3 corresponding to the embodiments.

In this magnetic tape cassette, a lower flange 46 is integrally formed, and a hub 48 having a center boss 52 at the center of the upper surface is formed with a center hole 66 through which the center boss 52 is inserted and a plurality of coupling holes 68 around the upper hole. A magnetic tape is wound around a tape reel 44 formed by uniting 50, and the center boss of the tape reel 44 is wound by a spring provided on the inner surface of the upper half 74.
The upper flange 50 is joined to the hub 48 by using a fixing ring 64 having a center hole 62 through which the center boss 52 of the same material as the hub 48 is inserted. The fastening ring 64 is attached to the upper surface of the hub 48 by the upper flange 50.
The upper flange 50 is sandwiched between the hub 48 and the fixing ring 64 by welding through a plurality of coupling holes 68 provided in the.

Operation The above means operates as follows.

A fixing ring 64 made of the same material as the hub 48 and having a center hole 62 through which the center boss 52 is inserted is used.
When the upper flange 50 is sandwiched between the hub 48 and the fixing ring 64 by welding through the plurality of coupling holes 68 provided on the upper flange 50 on the upper surface of the upper flange 50, the fixing ring 64 is connected to the hub 48.
Since the upper flange 50 is connected to the upper surface of the hub 48 by welding through all the connecting holes 68 provided therein, the upper flange 50 can be firmly fixed to the hub 48. At this time, only the center boss 52 projects from the upper surface of the tape reel 44, and the plurality of coupling holes 68 around the center boss 52 are all covered with the fixing ring 64. Moreover, the fixing ring 64 can be easily positioned after welding, and the upper surface and the center boss
Since it is easy to form a required height difference with the tip of 52, it is possible to prevent the tape reel pressing spring from coming into contact therewith. In addition, if the positioning after the welding to the fixing ring 64 is easy, naturally the performance is improved and the productivity is also improved.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a tape reel in a magnetic tape cassette according to the VHS-C system to which the present invention is applied, in which (a) is a sectional view taken along the line AA in FIG. 2 and (b) is an enlarged portion thereof. It is a figure. FIG. 2 is a plan view of the tape reel. In the figure, reference numeral 44 is a supply-side tape reel, in which a disc-shaped upper flange 50 is combined with a column-shaped hub 48 integrally formed with a disc-shaped lower flange 46. Therefore, a center boss 52 is provided at the center of the upper surface of the hub 48, and a plurality of, for example, four detent bosses 54 are arranged at equal intervals on a circle centered on the boss 52. Furthermore, on the outside thereof there is a edging protrusion 56 in the form of a circle. In addition, the upper flange 50 is a circular protrusion
A central portion 58 substantially corresponding to the inside of 56 projects downward to form a trapezoidal recess 60 on the upper surface, and through holes through which the center boss 52 and the rotation stop boss 54 are fitted are drilled at corresponding positions. I am doing it. An upper flange 50 for such a hub 48
A fixing ring 64 made of the same material as the hub 48 and having a center hole 62 through which the center boss 52 is inserted is used for the combination. The fixing ring 64 has upper and lower surfaces made parallel to each other, and both ends of the outer peripheral surface are chamfered to eliminate the directionality of the front and back surfaces.
At the time of uniting, the center portion 58 of the upper flange 50 is first fitted into the edging circular protrusion 56 of the hub 48 and placed thereon, the center boss 52 is inserted into the center hole 66 thereof, and the rotation preventing bosses 54 corresponding to the coupling holes 68 are fitted respectively. To do. Next, the fixing ring 64 is fitted into the recess 60 of the upper flange 50 and placed, and the center boss 52 is inserted into the center hole 62.
Insert again. Then, the lower part of the fixing ring 64 is welded to the upper part of the rotation-stopping boss 54 by using ultrasonic waves or heat. As a result, the fixing ring 64 is coupled to the upper surface of the hub 48 via the detent boss 54 in the coupling hole 68 of the upper flange 50,
The upper flange 50 is sandwiched between the hub 48 and the fixing ring 64.
The upper portion of the detent boss 54 has a central portion protruding in a mountain shape to form a welded portion 69, and there is a space around the welded escape portion 70 into which molten resin enters.

In this way, the fixing ring 64 having the center hole 62 through which the center boss 52 is inserted and made of the same material as the hub 48 is used, and the fixing ring 64 is provided on the upper surface of the hub 48 with a plurality of coupling holes of the upper flange 50.
When the upper flange 50 is sandwiched between the hub 48 and the fixing ring 64 by welding via the 68, the fixing ring 64 holds the upper flange 50 between the hub 48 and all the connecting holes provided there. The upper flange 50 can be firmly fixed to the hub 48 because the upper flange 50 is connected to the upper surface of the hub 48 by welding via 68. At this time, only the center boss 52 projects from the upper surface of the tape reel 44, and a plurality of coupling holes around the center boss 52 are provided.
All 68 are covered by the fixing ring 64. Therefore, when the fixing ring 64 is colored, this portion can be seen through a transparent window provided on the upper half plate of the upper half, so that the appearance is particularly improved and the appearance quality is improved. Further, when the fixing ring 64 has a flat upper surface, positioning is particularly easy after welding, and it is easy to form a required height difference between the upper surface and the tip of the center boss 52. Therefore, if the upper surface of the fixing ring 64 is determined to be lower than the upper surface of the upper flange 50, the tape reel pressing spring can be prevented from coming into contact therewith.
Therefore, shaving and uneven rotation do not occur, and erroneous recording and erroneous reproduction due to dropout and the like caused by them do not occur.
In addition, if the positioning after the welding to the fixing ring 64 is easy, naturally the performance is improved and the productivity is also improved.

FIG. 3 shows the external appearance of the completed assembly of the magnetic tape cassette according to the VHS-C method using the tape reel 44. The cassette case 72 is composed of upper and lower halves 74 and 76, and a magnetic tape is wound inside the cassette case 72, and a supply side tape reel 44 in which a center boss 52 is pressed by a spring provided on the inner surface of the upper half 74 is provided. It is stored. The case 72 also houses a take-up tape reel 78 which is paired with the supply tape reel 44, but a part of the lower flange thereof projects from the case 72 to the outside. Further, the entire opening of the case 72 is covered with a guard panel 80 that can be opened and closed. The guard panel 80 is locked when not in use and is in a closed state as shown in the figure, but when in use, when the cassette is mounted on the deck, the operation projection 82 is pushed to be unlocked and opened. Then, since the magnetic tape stretched on the front side of the front opening is exposed, the loading becomes possible. The amount of tape wound around the supply-side tape reel 44 can be seen from the transparent window 84 provided on the right side of the upper surface plate of the upper half 74.

FIG. 4 is an enlarged partial sectional view showing a modified example of a similar tape reel to which the present invention is applied. In this modification, the welding escape portion 88 (88) in which molten resin enters the upper and lower surfaces of the fixing ring 86.
a, 88b) There is a recess. For this reason, the sticking ring
It is sufficient to eliminate the directionality of the front and back sides of 86 and form the welded portion 92 by protruding the upper portion of the rotation-stop boss 90 in a mountain shape, but a welded escape portion can be further provided around it. The other structure is the same as that of the previous embodiment.

FIG. 5 is an enlarged partial sectional view showing another modified example of a similar tape reel to which the present invention is applied. In this modification, a detent boss 100 that fits into the coupling hole 98 of the upper flange 96 is projected downward from the lower surface of the fixing ring 94. For this reason, the detent boss 100 protrudes downward in the shape of a mountain at the center of the lower part, and
02 is formed, and a welding escape portion 104 is provided around it.
The other structure is the same as that of the previous embodiment.

Effect of the Invention According to the present invention described above, since the fixing ring is used, it is possible to obtain a product excellent in performance and appearance quality by eliminating erroneous recording, erroneous reproduction and the like. Also, productivity is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a tape reel in a magnetic tape cassette according to the VHS (registered trademark) -C system to which the present invention is applied, and FIG. 1 (a) is a sectional view taken along the line A--A of FIG.
The figure is an enlarged partial view thereof. FIG. 2 is a plan view of the tape reel. FIG. 3 is an external perspective view of the magnetic tape cassette. FIG. 4 is an enlarged partial sectional view showing a modified example of the tape reel, and FIG. 5 is a similar view showing another modified example. FIG. 6 is a schematic view showing the structure around a tape reel of a conventional VHS-standard magnetic tape cassette, FIG. 7 is a perspective view showing the supply-side tape reel in detail, and FIG. 8 is an enlarged partial sectional view thereof. Is. 44 …… Supply tape reel, 46 …… Lower flange, 48, 10
6 …… Hub, 50, 96 …… Upper flange, 52 …… Center boss, 54, 90, 100 …… Non-rotating boss, 58 …… Center part, 6
2, 66 …… Center hole, 64,86,94 …… Fixing ring, 68,98
...... Coupling holes, 69, 92, 102 …… Welded parts, 70, 88, 104 ……
Welding escape area, 72 …… Case, 74,76 …… Upper and lower halves, 78
…… Take-up tape reel, 80 …… Guard panel, 84 ……
Transparent window

Claims (4)

[Scope of utility model registration request] 1. A tape comprising a hub having a center boss at the center of its upper surface, which is integrally formed with a lower flange, and a center hole into which the center boss is inserted, and an upper flange having a plurality of coupling holes formed around the center hole. Wrap the magnetic tape around the reel,
In a magnetic tape cassette that is housed in a case by pressing the center boss of the tape reel with a spring provided on the inner surface of the upper half, using a fixing ring made of the same material as the hub and having a center hole through which the center boss is inserted. A magnetic tape cassette characterized in that the fixing ring is welded to the upper surface of the hub through a plurality of coupling holes provided in the upper flange, and the upper flange is sandwiched between the hub and the fixing ring. 2. A utility model registration according to claim 1, characterized in that a detent boss that fits into the coupling hole of the upper flange is protruded from the upper surface of the hub or the lower surface of the fixing ring and is welded. Magnetic tape cassette. 3. The magnetic tape cassette according to claim 1, wherein the upper surface of the fixing ring is located lower than the upper surface of the upper flange after the fixing ring is welded to the upper surface of the hub. 4. The magnetic tape cassette according to claim 1, wherein the fixing ring is colored.