JPH0351832Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape cassette such as a compact cassette, and more particularly to a magnetic tape cassette suitable for use at high temperatures.

Magnetic tape cassettes (hereinafter simply referred to as cassettes) such as compact cassettes and micro cassettes are convenient to carry, so they are often carried and used in various places, and they are also used at extremely high temperatures. Not a few. For example, a compact cassette placed inside a car for use in a car stereo may be exposed to high temperatures of about 50 to 60°C when the car is parked outdoors on a sunny day.

Generally, a roller for guiding the magnetic tape is provided inside the above-mentioned cassette, and this roller is usually rotatably supported by a metal rotation support shaft supported by the cassette half. There is. It is desirable for this type of roller to rotate smoothly in order to improve the running properties of the magnetic tape. Therefore, in conventional cassettes, lubrication such as silicone grease is generally applied between the rotation support shaft and the roller. drug was injected.

However, as mentioned above, it has been recognized that when the cassette is used and stored at high temperatures, this lubricant evaporates and gradually decreases. Naturally, if this lubricant decreases, the lubricating effect is lost, which adversely affects the tape running performance, and also causes unpleasant noises (roller squeal) when the roller rotates.

Considering the evaporation and reduction of lubricant as mentioned above,
It has been considered to inject a large amount of lubricant in advance, but if too much lubricant is injected, the lubricant may overflow outside the rollers and stain the magnetic tape while the cassette is in use. Additionally, aircraft grease, which does not evaporate or reduce in large quantities even when exposed to high temperatures, is used as the lubricant in some video cassettes.
Such aircraft grease is expensive, and it is not a good idea to use such aircraft grease for compact cassettes and the like, where price competition is particularly intense.

The present invention was developed in view of the above circumstances, and aims to provide a cassette at a low cost in which the lubricant on the roller rotation support shaft does not evaporate or decrease even when used and stored at high temperatures. This is the purpose.

In the cassette of the present invention, the rotational support shaft of the roller that guides the magnetic tape as described above is formed by a hollow cylindrical member having a through hole in at least a part of the peripheral wall, and the rotational support shaft of the hollow cylinder is formed in the hollow part of the rotational support shaft of the hollow cylinder. It is characterized by the fact that it is injected with lubricant.

The lubricant injected into the hollow part oozes out little by little from the through hole in the peripheral wall, adheres to the inner peripheral surface of the rotating roller, spreads between the inner peripheral surface of the roller and the rotating support shaft, and spreads around the roller. rotate smoothly. The upper and lower ends of the hollow rotary support shaft, into which lubricant is injected, are fitted into the rotary support shaft fixing portion of the cassette half, so that both ends of the rotary support shaft hollow portion are sealed. The lubricant will not evaporate or decrease at high temperatures.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a portion of a cassette according to one embodiment of the present invention. The cassette of this embodiment is a compact cassette, and a rotary support shaft 3 is installed on the side of the opening 2 of the cassette half 1, and a roller 4 is rotatably inserted into the rotary support shaft 3. Although not shown in FIG. 1, a similar roller is provided on the other side of the cassette half 1. A magnetic tape (not shown) whose ends are wound around two hubs is hung by these rollers, changes direction, and is stretched inside the opening 2. After the rollers 4, magnetic tape, etc. are assembled into the cassette half 1 as described above, the cassette half 1 is combined with the mating cassette half 10 to form a compact cassette.
At this time, the upper end of the rotation support shaft 3 in the drawing is fitted into the bearing hole 11 of the mating cassette half 10. Therefore, within the completed cassette, the rotary support shaft 3 is firmly fixed, and the roller 4 is supported by the rotary support shaft 3 and rotates to smoothly run the magnetic tape.

FIG. 2 shows an enlarged view of the rotation support shaft 3 described above. As shown in FIG. It is rolled up, and a hollow part 3a is formed in the center. Also, the seams 3b on both sides of the metal plates are not completely abutted, and for a while.
is formed. A lubricant 5 such as silicone grease is injected into the hollow portion 3a. This lubricant is injected using, for example, a syringe-like injector.

The lubricant 5 oozes out little by little from between the seams 3b, adheres to the inner peripheral surface of the rotating roller 4, and is spread over the entire outer peripheral surface of the rotating support shaft 3. In this way, a lubricating film is formed between the outer circumferential surface of the rotation support shaft 3 and the inner circumferential surface of the roller 4, so that the roller 4 rotates smoothly and good tape running performance is obtained. Further, as shown in FIG. 1, the lower end in the figure of the rotary support shaft 3 into which the lubricant 5 is injected is installed in the bearing hole 6 of the cassette half 1, and the upper end is also connected to the mating shaft 3 as described above. Since it is fitted into the bearing hole 11 of the side cassette half 10, the hollow portion 3a of the rotary support shaft 3 is sealed from above and below. And between the seams 3b, lubricant 5
It is sufficient that the lubricant 5 has a width that allows the lubricant to ooze out little by little, so the lubricant 5 injected into the hollow portion 3a becomes extremely difficult to come into contact with the external atmosphere. Therefore, even if the cassette is used or stored at high temperatures, the lubricant 5 in the rotary support shaft 3 will not evaporate or decrease. Note that the rotation support shaft 3 as described above can be manufactured at approximately the same cost as a conventional rotation support shaft made of rod-shaped metal.

In the above embodiment, a spring pin-shaped rotation support shaft 3 made of a single rectangular metal plate rolled into a hollow cylindrical shape is used, but the rotation support shaft is not limited to this shape. Any cylindrical member may be used as long as it has a hollow part into which the lubricant is injected and a hole through which the lubricant oozes out.For example, as shown in FIG. 3, the joint 20b of the metal plate 20a is formed in a wave shape rotation support shaft 20, or the fourth
As shown in the figure, a rotation support shaft 30 having one or more through holes 30b provided in the peripheral wall of a cylindrical member 30a may be used.

As explained in detail above, the cassette of the present invention is
The lubricant for roller lubrication does not evaporate or decrease even when used and stored at high temperatures, so there is no need to use special and expensive lubricants, and the unique rotating support shaft of this invention Since the cassette of the present invention can be manufactured at a cost comparable to that of a conventional rotary support shaft, it can be said that the cassette of the present invention is inexpensive but can sufficiently withstand use at high temperatures. Furthermore, in the cassette of the present invention, the lubricant is injected and held in the hollow part of the rotary support shaft, so if a groove is provided in the peripheral wall of the rotary support shaft and the lubricant is injected and held there. Compared to this, it is possible to inject and hold more lubricant and maintain good tape running performance for a longer period of time.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is an enlarged perspective view of a part of the embodiment shown in FIG. 1, and FIG. 3 is a perspective view showing another embodiment of the present invention.
FIG. 4 is a perspective view showing still another embodiment of the present invention. 3, 20, 30...Rotation support shaft, 4...Roller, 5...Lubricant, 3a...Hollow part, 3b, 20
b... seam, 30b... through hole.

Claims (1)

[Scope of utility model registration request] A magnetic tape characterized in that a rotation support shaft of a roller that guides the magnetic tape is made of a hollow cylindrical member having a through hole in at least a part of the peripheral wall, and a lubricant is injected into the hollow part of the rotation support shaft. Cassette.