JPH0521753Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a tape cassette containing a reel wound with tape.

BACKGROUND ART Conventionally, this type of tape cassette has been constructed as shown in FIG. In FIG. 2, 1 is a half, and reels 3 and 4 on which a magnetic tape 2 for recording and reproducing video signals is wound are accommodated therein.
The outer periphery of the flange portion of the reel 3 is provided with a tooth portion 5 that meshes with a gear provided in a device to which the tape cassette is mounted and which records and reproduces signals.

A boss is provided on the outside of the half 1 coaxially with the reel 3 in order to accurately regulate the relative position of the tooth portion 5 and the gear of the device described above. FIG. 3 is a sectional view of a main part showing the structure of this part, and a metal shaft 7 is fixed to the half 1 by a boss 6. Here, the boss 6 has a machine screw shape. When this tape cassette is attached to a device, the boss 6 fits into a recessed hole 8 provided in the device, so that the gear 9 provided in the device and the teeth 5 of the reel 3 can mesh accurately. .

As shown in Fig. 4, another conventional method is
A metal shaft 7 integrally provided with a boss 6 has also been fixed to the half 1 by press-fitting a press-fitting part 10 in the middle thereof into the half 1. The press-fitting part 10 is formed with so-called cross-cut knurling by plastic deformation to prevent the shaft 7 from falling off from the half 1 or rotating relative to the half 1.

Problems to be Solved by the Invention In such a conventional configuration, the metal of the shaft 7 and boss 6 shown in FIG. 3 must be machined, which is expensive.
In addition, in the configuration shown in FIG. 4, the shaft 7 and the boss 6 are integrated, which is rational, but it is inevitably expensive because the metal is forged and cut. There was a problem that the outer diameter of the half 1 was difficult to maintain accuracy due to its cross-knurling process, making it difficult to maintain a constant press-fitting force for the half 1.

This invention solves these problems,
It is an object of the present invention to provide a tape cassette having a structure of a shaft and a boss that is cheaper and easier to achieve accuracy.

Means for Solving the Problem In order to solve this problem, the present invention has a shaft for pivoting the reel inside the half that accommodates the reel wound with tape, and a shaft coaxially with the shaft on the outside of the half. The main body is equipped with a boss for positioning with respect to a recording/reproducing device to which the main body is mounted, and the half, shaft, and boss are integrally molded.

Effect: This configuration allows shafts and bosses to be manufactured at a significantly lower cost without any loss of conventional functionality. Scraping of the boss due to fitting with the recessed hole can be prevented, and for example, by providing at least two through holes in the half near the boss, the coaxiality of the shaft and the boss can be easily inspected. becomes.

Embodiment FIG. 1 is a sectional view of a main part of a tape cassette according to an embodiment of the present invention, and hereinafter, parts corresponding to those of the conventional example will be explained using the same numbers.

In FIG. 1, the half 1 has a shaft 7 that pivots a reel 3 on which a tape is wound, and a shaft 7 that fits into a recessed hole provided in a device that records and plays signals to which this tape cassette is attached. A boss 6 for positioning is integrally molded.

Since the recessed hole of the above-mentioned equipment is usually made of metal, the boss 6 is made of ordinary polystyrene resin or
If it is made of ABS resin, the boss 6 will fit into the recessed hole.
There is a risk that the outer periphery of the Therefore, in this embodiment, as the material for molding these bosses and the like, styrene resin or similar ABS resin, which is mixed with a lubricant to improve the lubricity of the surface of the molded product, is used. As a lubricant to be mixed, silicon is the most suitable in terms of effectiveness and economy, and its mixing ratio with respect to the base material is preferably 0.5 to 2%. This is because if the mixing ratio is less than 0.5%, the effect of improving lubricity is poor, and if it exceeds 2%, moldability will be impaired. The lubricant may be other than silicone, for example, powder of tetrafluoroethylene, and in that case, the appropriate mixing ratio will be different from the above value.

In this way, when the shaft 7 and the boss 6 are integrally molded on both the inside and outside surfaces of the half 1, the shaft 7 is formed in the mold on the core side,
Since the boss 6 is molded using a mold on the cavity side, it is necessary to measure the coaxiality of the boss 6 with respect to the axis 7. In order to make this measurement possible, in this embodiment, through holes 11 and 12 were further provided in the vicinity of the shaft 7 and boss 6 of the half 1. Since it is a through hole, it can be used as a measurement reference from either the inside or outside of the half 1, and since there are two through holes, the shaft 7 and boss 6 can be The relative positions can be measured respectively, and therefore the relative positions of the shaft 7 and the boss 6 can be measured indirectly via the through holes 11 and 12.

Note that a hollow hole 13 was provided in the boss 6 to prevent sink marks during molding.

Effects of the Invention As described above, according to the present invention, it is possible to obtain an inexpensive tape cassette with a simple structure without impairing the conventional functions.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of a tape cassette according to an embodiment of the present invention, FIG. 2 is a perspective view of a conventional tape cassette, FIG. 3 is a cross-sectional view of a main part thereof, and FIG. FIG. 3 is a sectional view of a main part showing an example. 1...half, 3...reel, 6...boss, 7
...Shaft, 11, 12...Through hole.

Claims (1)

[Claims for Utility Model Registration] 1. A shaft for pivotally supporting the reel inside a half that accommodates a reel wound with tape, and a main body mounted coaxially with the shaft on the outside of the half for recording and reproducing. 1. A tape cassette comprising a boss for positioning with respect to a device to be used, and wherein the half, shaft, and boss are integrally molded. 2. The tape cassette according to claim 1, which is molded from styrene resin or ABS resin mixed with a lubricant such as silicone. 3. The tape cassette according to claim 1, wherein at least two through holes are provided in the half near the shaft.