JPH075590Y2 - Tape cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a tape cassette, and in particular, a tape-shaped recording medium wound around a pair of reels is housed in a casing, and a part of the casing The present invention relates to a tape cassette in which the tape-shaped recording medium is guided by a guide portion provided on the head and is brought into contact with the head for recording and / or reproduction.

[Background technology and its problems]

2. Description of the Related Art In order to perform recording and / or reproduction by a tape recorder, a tape cassette in which a magnetic tape wound around a reel is contained in a casing has been widely used. Conventionally, general-purpose resins, that is, synthetic resins such as AS resin, polystyrene resin, and ABS resin have been used for the casing of such a tape cassette. A tape cassette including a casing formed of such a synthetic resin causes modulation noise due to external vibration generated by a motor of a tape recorder and vibration generated by sliding resistance between a tape and a guide pin in the casing. There was a problem that it would occur.

In order to reduce the modulation noise due to such vibration, it is necessary to use a resin having a large effect of damping the vibration transmitted from the outside, that is, a resin having a large internal loss and a small resonance sharpness, for the cassette casing. preferable. However, on the other hand, the cassette casing is provided with a guide portion integrally with the casing, and in order to prevent the vibration due to the stick slip in the guide portion, a resin having a high rigidity and a high elastic modulus and a low friction coefficient is used. Is preferably used. Therefore, the required properties of the cassette casing differ between the guide portion and the other portions.

In view of such a problem, while molding the cassette casing with a synthetic resin that attenuates external vibration,
Japanese Unexamined Patent Publication (Kokai) No. 59-124073 discloses a tape cassette in which a guide portion is molded separately from a casing by a synthetic resin containing ceramic. With such a configuration, it is possible to provide a tape cassette that can satisfy the physical properties required for each part. However, according to such a configuration, not only the number of parts of the tape cassette increases, but also the number of assembling steps increases, or automation of the assembling is hindered, resulting in an increase in the cost of the tape cassette.

[Purpose of device]

The present invention has been made in view of such problems, and the guide portion does not generate vibration due to stick-slip with the tape-shaped recording medium, and the portion other than the guide portion is externally applied. It is an object of the present invention to provide a tape cassette including a casing adapted to block vibration of the tape cassette.

[Outline of device]

The present invention accommodates a tape-shaped recording medium wound around a pair of reels in a casing, and guides the tape-shaped recording medium by a guide portion provided in a part of the casing. In a tape cassette adapted to record and / or reproduce by contacting each other, the other part of the casing other than the guide part is made of a thermoplastic resin, and the part of the guide part is the same as the thermoplastic resin. A state in which two parts made of different materials are joined by double molding by mixing ceramics into the resin of the system to increase rigidity and elastic modulus and lowering the coefficient of friction. The present invention relates to a tape cassette, which is characterized by being integrally molded by means of double molding. By, it is possible to a portion and another portion of the guide portion and the respective desired properties.

〔Example〕

The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 shows a tape cassette according to an embodiment of the present invention, which has a cassette casing 1. The cassette casing 1 includes a pair of upper and lower halves 2 and 3 formed of synthetic resin, and the reels 4 and 5 are arranged in the halves 2 and 3. Both ends of the magnetic tape 6 are fixed to the reels 4 and 5, respectively, and are housed in the casing 1 while being wound around the reels 4 and 5.

The magnetic tape 6 is hung by a pair of left and right guide rollers 7 on the inside of a front side wall portion having a head insertion opening 8 and a pinch roller insertion opening 9, respectively. Further, for example, the lower half 3 is integrally formed with a guide projection 10 so that the magnetic head inserted from the head insertion port 8 and the magnetic tape 6 are correctly brought into contact with each other. Sliding sheets 11 are provided above and below the pair of reels 4 and 5, respectively, so that the magnetic tape 6 can be stably guided by the protrusions 10. These slippery sheets 11 are provided with circular holes 12 so that the annular projections 13 of the halves 2 and 3 constituting the cassette casing 1 engage with the reels 4 and 5, respectively. ing.

Next, a method of molding the cassette casing 1 of the tape cassette will be described. The upper and lower halves 2 and 3 are both formed by double molding. The guide projections shown by dots in FIG. The front portion including 10 and the other portions are formed of different materials. That is, the guide portion 10 is formed of a resin mixed with a ceramic having high rigidity and elastic modulus and a small friction coefficient so as not to generate vibration due to stick-slip with the magnetic tape 6. On the other hand, the portion other than the guide portion, that is, the portion not dotted in FIG. 1, is molded from a resin having a large internal loss and a small resonance sharpness so as to block external vibration. It has become.

When molding the halves 2 and 3 of the casing 1 as described above, first, as shown in FIG. 2, a common upper mold 16 and a first lower mold 17 are used for molding. These pair of molds
A cavity 18 is formed between the both 16 and 17. Since the cavity 18 communicates with the injection port 19, the thermoplastic resin mixed with the ceramic is injected through the injection port 19 and the guide portion (the dotted portion in FIG. 1) 20 To mold. Here, as the thermoplastic resin, various synthetic resins such as polypropylene, polyoxymethylene, nylon, ABS resin and polystyrene may be used.

Next, the upper die 16 is placed on the turntable (not shown)
Rotate it by 0 degrees and move the upper mold 16 to the second position as shown in FIG.
It is fitted with the lower mold 21 of. At this time, the upper mold 16 is left with the guide portion 20 still attached. Then upper mold 16
A cavity 22 is formed between the second lower mold 21 and the second lower mold 21, and the cavity 22 communicates with an injection port 23 formed in the lower mold 21. Therefore, a resin for molding a portion other than the portion 20 of the guide portion is injected through the injection port 23. That is, a thermoplastic resin such as polypropylene, polyoxymethylene, nylon, ABS resin, polystyrene is injected. In this case, a resin of the same quality as the resin for molding the guide portion 20 is used correspondingly. This is to obtain the bonding strength between the guide portion 20 and the other portions.

Thus, in the tape cassette according to the present embodiment,
The portion 20 of the guide portion of the cassette casing 1 is made of a thermoplastic resin containing ceramic, the other portion is made of a usual thermoplastic resin, and both are integrally joined by double molding. There is. Therefore, the portion of the guide portion 20 has higher rigidity and elastic modulus than other portions, the portion of the guide portion 20 has a higher resonance sharpness than other portions, and its specific gravity is also higher than that of other portions. Become. Therefore, the rigidity and elastic modulus of the guide portion 20, that is, the portion shown by dots in FIG. 1 is higher than that of the other portions, and the friction coefficient with the magnetic tape 6 is low, so that the guide It is possible to prevent the occurrence of vibration due to stick slip between the portion 10 and the magnetic tape 6. Further, since the portion other than the guide portion 20 is molded from a normal synthetic resin, it is possible to damp external vibrations and thereby prevent generation of modulation noise.

Next, a molding method according to the modified example will be described with reference to FIGS. In this modified example, molding is performed by a mold having a slide core. That is, as shown in FIG. 4, the die is composed of an upper die 26 and a lower die 27, and a sliding hole 28 is formed in the lower die 27.
The slide core 29 is slidably held. And in the beginning, slide core 29
Is raised and its upper surface is brought into close contact with the lower surface of the upper mold 26. In this state, a resin material having a small resonance sharpness is injected into the cavity 30 formed between the upper and lower molds 26 and 27 from the horizontal injection port 31, and the portion other than the guide portion (dotted points in FIG. 1 are marked. Mold part 32).

After this, as shown in FIG. 5, the slide core 29 is lowered with respect to the lower die 27 to form a cavity 35 between the slide core 29 and the upper die 26. Then, a hard material having a high elastic modulus and a high resonance sharpness is injected into the cavity 35 from the injection port 33 on the upper side to mold the portion 34 of the guide portion. After that, the upper and lower molds 26 and 27 are separated from each other and opened as shown in FIG. 6, so that the cassette halves 2 and 3 held on the lower mold 27 can be taken out.

[Effect of device]

As described above, according to the present invention, the other parts of the casing other than the guide part are made of a thermoplastic resin, and the guide part part is mixed with a ceramic in a resin of the same type as the thermoplastic resin to improve rigidity and elastic modulus. It is made of a thermoplastic resin having a high coefficient of friction and a low coefficient of friction, and two parts made of different materials are integrally molded by double molding in a state of being connected to each other.

Therefore, according to the present invention, the guide portion for guiding the tape-shaped recording medium and the other portions can be made of materials having desired physical properties. In particular, the guide portion made of a thermoplastic resin in which ceramic is mixed to increase the rigidity and elastic modulus and to reduce the friction coefficient can prevent vibration due to stick-slip with the tape-shaped recording medium. Moreover, the modulation noise can be effectively and surely reduced by the other portion made of the usual thermoplastic resin. Moreover, since the guide part and the other part are integrally formed by double molding, the number of assembling steps does not increase, and the automatic assembling is possible, and the cost increase of the tape cassette can be suppressed. Become. Further, since the guide portion and the other portion are made of the same type of thermoplastic resin and the resin in which the ceramic is mixed is used on the guide portion side, the bonding strength between them is sufficiently high.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a tape cassette according to an embodiment of the present invention, FIG. 2 is a vertical sectional view showing a die for molding a casing of the tape cassette, and FIG. Fig. 4 is a vertical cross-sectional view of a mold according to a modified example, Fig. 5 is a vertical cross-sectional view of the mold with the slide core lowered, The figure is a vertical cross-sectional view of the same mold in an opened state. In the reference numerals used in the drawings, 1 ... cassette casing 2 ... half (top) 3 ... half (bottom) 4,5 ... reel 6 ... magnetic tape 10 ... guide projection 16 ... upper mold 17 …… First lower mold 20 …… Guide part 21 …… Second lower mold 26 …… Upper mold 27 …… Lower mold 29 …… Slide core 32 …… Other than guide part 34 …… Guide It is a part of the department.

Continuation of the front page (56) References JP-A-59-124072 (JP, A) JP-A-59-48135 (JP, A) Actual development 57-201325 (JP, U) JP-B-49-26578 (JP) , B1) JP-B 2-58710 (JP, B2) JP-B 60-29335 (JP, B2) JP-B 51-30766 (JP, B2) JP-B 4-49189 (JP, B2) JP 63-38469 (JP, Y2)

Claims (1)

[Scope of utility model registration request] 1. A head which accommodates a tape-shaped recording medium wound around a pair of reels in a casing and guides the tape-shaped recording medium by a guide portion provided in a part of the casing. In a tape cassette adapted to perform recording and / or reproduction by contacting with the other part, the other part of the casing other than the guide part is made of a thermoplastic resin, and the part of the guide part is made of the thermoplastic resin. A state in which ceramics are mixed in homogenous resin to increase rigidity and elastic modulus and to reduce friction coefficient, and the two parts made of different materials are joined together by double molding. A tape cassette characterized by being integrally molded with.