JPS6323821Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a tape cassette, and particularly to a tape guide roller molded from synthetic resin.

The tape guide roller 1 shown in Fig. 1, which is used in the microcassette (product name) that is currently widely used, is made of synthetic resin like the cassette half 2, etc., but the tape guide roller 1 is particularly low Resin such as polyacetal is used for friction reasons.

However, these resins have a large thermal shrinkage rate,
Thickness shrinkage occurs at the corner portion, that is, at the end peripheral edge 3 of the tape guide roller 1, and even if an attempt is made to provide a relief to prevent the thinness shrinkage, the tape guide roller 1 is too small to be provided. For this reason, the tape guide roller 1 with thinning as shown in FIG.
However, due to the shrinkage of the tape, the tape 5 could not be run correctly, resulting in a decline in performance during recording and playback.

The object of this invention is to provide a tape cassette which eliminates the above-mentioned drawbacks, allows good tape running with a simple structure, and improves performance.

An embodiment of this invention will be described below with reference to the drawings. FIG. 2 shows a cassette half 7 into which a molded tape guide roller 6 is fitted, and the cassette half 7 has mounting bosses 8 at substantially four corners.

As shown in FIG. 3, the tape guide roller 6 is formed to have a height that is 1.4 times or more the width of the tape 5. That is, the guide roller 6 is a mold made to be 1.4 times wider than the width of the tape 5.
It is molded using a low-friction resin such as polyacetal, and the edges 9 at both ends have a=approximately 0.7.
~1.2mm, b = approximately 0.01~0.03mm shrinkage.

However, since the height of the guide roller 6, that is, the width of the surface in contact with the tape 5, is more than 1.4 times the width of the tape, there is less possibility that the stepped part due to shrinkage will reach the contact part of the tape 5. 5 is designed to come into contact with a flat surface.

On the other hand, since the tape guide roller 6 molded in this way is long, the shaft 10 of the cassette half 7 on which the tape guide roller support shaft 10 is erected is
The periphery is annularly recessed as shown in FIG. 4, and the end of the tape guide roller 6 is located in the recess 12, but the tape 5 is not located in the recess 12.

Further, a similar recess 14 is provided in a cassette half 13 that is paired with the cassette half 7, and a tape guide roller 6 is rotatably disposed between the recesses 14.

Note that the stepped portions 15 provided on the side walls of the cassette halves 7, 13 are tape guides.

FIG. 5 shows a section of the cassette half attachment boss 8, and the tape 5 is stretched between the tape guide roller 6 and the tape guide pin 16 so as not to contact the boss 8. ing.

When using a tape guide roller molded in this way, even if there is shrinkage on both ends, there will be no problem with tape running, and performance can be improved based on extremely good tape running. can.

Furthermore, since the tape guide is provided around the tape guide roller, the tape wrapping angle can be increased to approximately 90 degrees, making it possible to fully utilize the tape guide's effectiveness.

The width of the tape guide roller is preferably in the range of 1.4 to 2 times; if it is less than 1.4 times, there will be an adverse effect of thinning, and if it is more than twice the width, the concave portion of the cassette half will become thin, causing problems in terms of strength.

As detailed above, the tape cassette of this invention has a tape guide roller that has a width that is more than 1.4 times the tape width and is molded into a cylindrical shape from a synthetic resin material, and supports the tape guide roller in a rotatable manner. a tape guide roller support shaft, one cassette half having a recess in which one end of the supported tape guide roller is located but no tape is located, and one cassette half in which the other end of the supported tape guide roller is located. However, since the tape is equipped with the other cassette half which has a concave portion where the tape is not located, even if there is a crevice at both ends of the tape guide roller, it will not impede the running of the tape, and the tape will run properly. Good recording and playback can be performed.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional tape guide roller.
Fig. 2 is a cassette half diagram for explaining this invention, Fig. 3 is a sectional view of the tape guide roller portion and the surrounding cassette half showing an embodiment of this invention, and Fig. 4 is a tape guide of the same example. FIG. 5 is a plan view of the roller support shaft portion, and a sectional view of the cassette half attachment boss portion of the same example. 5...Tape, 6...Tape guide roller,
7,13...cassette half, 8...boss, 9...
...Flat shrinkage, 10...Tape guide roller support shaft,
12, 14... recess, 15... tape guide.

Claims (1)

[Scope of claim for utility model registration] A tape guide roller molded into a cylindrical shape from a synthetic resin material and having a width of at least 1.4 times the tape width, and a tape guide roller support shaft that rotatably supports the tape guide roller. and one cassette half having a recess in which one end of the supported tape guide roller is located but no tape is located, and a recess in which the other end of the supported tape guide roller is located but no tape is located. A tape cassette comprising: the other cassette half having;