JPH0127191Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention is based on a tape cartridge that has a hub around which tape is wound on the left and right sides of the inside of the main body case, and a separate sheet is interposed between the end face of the hub, the tape edge, and the inner wall surface of the main case. The main objective is to improve the windability of the tape around the hub and to reduce frictional noise by making distinctive improvements to the combination of surface shapes and surfaces. For example, FIGS. 1 and 2 illustrate a standard specification Phillips tape cartridge to which the present invention is applied, and its main body case 1 has upper and lower cases 1a and 1b screwed together with lids mating together. It has vertically penetrating drive shaft insertion holes 2, 2 on the left and right sides of the central portion. The inside of the main body case 1 has a pair of hubs 4, 4 on the left and right sides around which the tape 3 is wound, and each hub 4 is located above each drive shaft insertion hole 2 and rotates freely. The tape 3 is unwound from one hub 4, passes through an erasing head insertion window 5 on the front of the case, a magnetic head insertion window 6, and a pinch roller insertion window 7 in order, and is wound onto the other hub 4. Upper and lower case 1
A transparent window 8 is formed at the center of each of the hubs a and 1b, and the amount of tape 3 wrapped around each hub 4 can be visually confirmed through the transparent window 8. And main case 1
Two upper and lower separate sheets 10, 10 are interposed inside the hubs 4, 4, and the upper and lower edges of the tape 3 wound around the hubs are interposed, and the separate sheets 10 ensure smooth rotation of each hub 4. This is to ensure smooth running of the tape 3. Each separate sheet 10 has a rectangular punch hole 11 in the center thereof corresponding to the transparent window 8, and circular through holes 12, 12 corresponding to the drive shaft insertion holes 2, 2 on the left and right sides thereof.
It has a basic shape with each hole. Originally, this type of separate sheet 10 slidably contacts the hub end face and tape edge to ensure smooth rotation of the hub 4 and smooth running of the tape 3, and elastically presses the hub end face and tape edge to keep the tape 3 against the hub 4. This is to prevent irregular winding, that is, to improve the winding performance, thereby ensuring stability in tape running. Therefore, firstly, the material must be low friction and wear-resistant, and secondly, the sheet surface that comes into sliding contact with the hub 4 and tape 3 must have a surface configuration that is effective for abrasion resistance and particularly for reducing friction noise. Thirdly, it is required that the overall shape is such that the holding function of the hub 4 and the tape 3 is sufficiently exerted. In order to meet such demands, conventionally, the entire shape of the separate sheet 10 is curled into a convex shape as shown in FIG.
It is generally adopted that the vertical movement of the hub 4 and the tape 3 is elastically suppressed by a to improve the winding property. However, although it depends on the sheet material in this overall shape, since the front and rear span S in contact with the inner wall of the case is large, the pressing force against the hub 4 and tape 3 is weak to begin with, and after repeated use, it becomes flat. , the presser function is reduced early and the winding performance is poor. Therefore, the present applicant first proposed that the overall shape of the separate sheet 10 is as shown in FIGS. The hub 4 and the tape 3 are elastically sandwiched between the protrusions 13 and the convexly curved sheet surface 10a between the two protrusions 13, 13, with the protrusions 13 in contact with the inner wall surface of the case. (1987-)
No. 147535). In this case, the holding function of the hub 4 and tape 3 by the separate sheet 10 could be ensured for a long period of time, and the winding performance could be improved.
However, if this presser function is increased, the sheet surface 10a may wear out early depending on the material of the separate sheet 10, and even if both abrasion resistance is ensured, the rubbing noise will be high when the tape is running, especially when the tape is rapidly fed. Too much. Even if the separate sheet 10 is embossed with fine irregularities to reduce the rubbing area, it has little effect on reducing the rubbing noise, and the sheet surface 1
It was also found that there was a need to improve the surface morphology of Oa. Focusing on this fact, this invention further develops and improves the conventional separate sheet, maintains the holding function of the hub 4 and tape 3 by the separate sheet 10, and improves the neatness of winding the tape 3 around the hub 4. The purpose is to ensure that the surface of the sheet is protected from wear and to reduce frictional noise. That is, the present invention has the above-mentioned through holes 12, 1 on the left and right sides.
2, two protrusions 13, 13 running in the left-right direction are formed in front and rear positions sandwiching these through holes 12, 12 so as to protrude toward the sheet back surface 10b side, and between both protrusions 13, 13. The interval l is set larger than the diameter d of the through hole 12 and narrower than the outer diameter D of the hub 4.
The sheet surface 10a is mirror-finished so that the 10-point average roughness Rz is 1.0 μm or less,
As a result, both protrusions 13, 13 come into contact with the inner wall surface of the case,
It is characterized in that the convexly curved sheet surface 10a side comes into elastic contact with the hub 4 and the tape 3. Examples of the material for the separate sheet 10 include polybutylene terephthalate, polyethylene terephthalate, and polytetrafluoroethylene resin mixed with a conductive material such as graphite powder or carbon to prevent static electricity. Among these, separate sheets made of polytetrafluoroethylene resin have low friction properties and have been widely used for a long time, but their abrasion resistance is insufficient, and the sliding surface with the hub and tape edge wears into powder. The abrasion powder adheres to the tape and has an adverse effect. Moreover, it is weak and easily torn, and the sheet lacks shape retention. Furthermore, since polytetrafluoroethylene resin has poor film forming properties, it has to be cut into a sheet form from a block molded product and then subjected to shaping processing, resulting in poor moldability. On the other hand, although separate sheets made of polyethylene terephthalate are stronger than separate sheets made of tetrafluorinated polyethylene resin, they have poor slipperiness due to their large coefficient of friction, and when biaxially stretched sheets are used, they cannot be shaped easily. Processability is extremely poor, and if an unstretched sheet is used, the heat resistance is poor, so problems remain in terms of shape retention, durability, dimensional stability, etc. of the shaped separate sheet. In this regard, separate sheets made of polybutylene terephthalate are extremely strong and hard to tear, and have a friction coefficient of about 0.18~
As low as 0.3, good slipperiness and wear resistance can be ensured.
It is especially desirable because it has extremely good heat resistance, so it has excellent shape retention properties and dimensional stability, and because it has good film forming properties, it can be used without being stretched, and it has excellent processability and formability. I can say that. The separate sheet 10 according to the present invention is produced by heating and pressing a sheet material with a mirror roll to form a sheet surface 1
Mirror processing is performed on 0a. The surface roughness of the sheet surface 10a is desirably 1.0 μm or less, preferably 0.5 μm or less in ten-point average roughness Rz according to the measurement method of JIS BO610. Next, to explain the overall shape of the separate sheet 10 according to the present invention in more detail, as shown in FIGS. 3 and 4, the separate sheet 10 has a generally horizontally elongated shape, with the transparent window in the center part. 8
A rectangular punch hole 11 corresponding to the drive shaft insertion hole 11, and circular through holes 12, 12 corresponding to the drive shaft insertion holes 2, 2 on the left and right sides thereof.
are perforated in each case, and the main body case 1 is installed at the front and back of the central part.
It has positioning notches 17 and 18 that engage with side pins 15 and 16. In this separate sheet 10, the through holes 1 are arranged around the through holes 12.
Two parallel protrusions 1 extending in the left-right direction with an interval 1 larger than the diameter d of the hub 2 and narrower than the outer diameter D of the hub 4.
3 and 13 are plastically processed under heating to form the back surface 10 of the sheet.
A protrusion is formed on the b side. Further, the space between the protrusions 13, 13 is formed in a convex shape toward the sheet surface 10a, and the sheet surface 10a is rolled with a mirror roll to give it a mirror finish. This separate sheet 10 is assembled so that the protrusions 13, 13 are in contact with the inner wall surface of the case, and the sheet surface 10a is in contact with the end surface of the hub 4 and the tape edge. And the tape 3 is held elastically. The illustrated separate sheet 10 is also formed with a convex curve on the sheet surface 10a side between the front edge 10c and the protrusion 13 and between the rear edge 10d and the protrusion 13, so that the sheet surface 10a is Although the entire surface is mirror-finished, the convexly curved shape may be formed only between the protrusions 13, 13. In addition, each protrusion 1
3 may have a ridge-like cross-sectional shape as shown in FIG. Any material may be used as long as the sheet surface 10a between them functions to come into elastic contact with the hub end face or the tape edge. According to the tape cartridge of the present invention incorporating the separate sheet 10 configured as described above, the hub 4 and the tape 3 are elastically sandwiched between the separate sheets 10, 10 within the main body case 1, so that the hub 4 and the tape 3 can move up and down. This was suppressed as much as possible, and the tape 3 was wound on the hub 4 in an orderly manner. In order to evaluate the uniform winding effect of this invention, the maximum unevenness t at the edge portion of the rolled layer 3a of the tape 3 wound around the hub 4 was measured using a surface roughness meter as shown in FIG. In the case of the separate sheet according to the present invention having the shape shown in Fig. 3, t = 55 μm, whereas in the case of the separate sheet shown in Fig. 7 without the protrusions 13, t = 200 μm, and the protrusions 13 It was found that the protruding process was extremely effective in improving the winding properties. Nevertheless, the separate sheet 1 of the present invention
0 hub 4 and sheet surface 1 in contact with tape 3
Since the surface 0b is mirror-finished and has a smooth surface, the sliding resistance between the end face of the hub 4 and the tape edge is extremely small, and the rubbing noise during tape running can be significantly reduced. That is, the relationship between the surface roughness of the separate sheet 10 and the rubbing noise during tape running is as shown in the following table. Here, the surface roughness is expressed using the measurement method according to JIS B0610, where Rmax is the maximum height, Ra is the center line average roughness,
Rz indicates the 10-point average roughness. In addition, the tape running sound level dB was measured 10 cm away from the tape cartridge.

[Table] As is clear from this table, even with the separate sheet 10 made of polytetrafluoroethylene resin, which has excellent low friction properties, the surface roughness of the sheet surface 10a that directly contacts the hub 4 and tape 3 is sufficiently mirror-like. It can be seen that if the tape is not treated, the rubbing noise, that is, the level of the tape running sound is high, and the surface roughness is important for reducing the running sound level, especially when the tape is fast forwarded. In other words, the 10-point average roughness of polybutylene terephthalate separate sheet 10
If a certain quality of Rz of 0.72 μm or less is ensured, the running sound level during tape fast forwarding can be tolerated.
I found out that it is possible to reduce the noise level to 50dB or less. It was also confirmed that if the ten-point average roughness Rz of the sheet surface 10a was 0.5 μm or less, the sheet was still perfect regardless of the material. However, even if the ten-point average roughness Rz is 0.3 μm or less, it is assumed that there will not be much effect in reducing the tape running sound level. As explained above, the separate sheet 10 according to the present invention has two protrusions 13, 13 extending in the left-right direction formed in front and rear positions sandwiching the left and right through holes 12, 12 so as to protrude toward the sheet back surface 10b. At the same time, the interval l between both protrusions 13, 13 is set larger than the diameter d of the through hole 12 and narrower than the outer diameter D of the hub 4, and the space between both protrusions 13, 13 is curved convexly toward the seat surface 10a side. Since the separate sheet 10
The tape 3 reliably comes into elastic contact with the hub 4 and the tape 3 to suppress their vertical movement, and the tape 3 can be wound around the hub 4 in an orderly manner. After that, hub 4
Since the sheet surface 10a in contact with the tape 3 is mirror-finished so that the ten-point average roughness Rz is 1.0 μm or less, the sliding resistance between the end face of the hub 4 and the tape edge is extremely small, and the rotation of the hub 4 and the tape 3 runs smoothly,
This has the advantage that the running sound level during tape running can be dramatically reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing an embodiment of a separate sheet according to the present invention, FIG. 2 is a sectional view taken along the line -- in FIG. 1, FIG. 3 is a plan view of the separate sheet, and FIG. FIG. 5 is an enlarged side view of the separate sheet and a front view showing a state in which the tape is wound around the hub. FIG. 6 is a side view showing another embodiment of the separate sheet according to the present invention. 7th
The figure is a perspective view showing the overall shape of a conventional separate sheet. 1... Main body case, 2... Drive shaft insertion hole, 3...
...Tape, 4...Hub, 10...Separate sheet, 10a...Surface of separate sheet, 10b
... Back side of separate sheet, 12 ... Through hole, 1
3...Protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] A hub 4 wrapped with tape 3 on the left and right sides of the inside of the main body case 1 is positioned over each of the left and right drive shaft insertion holes 2 and is rotatably installed, and the inner wall surface of the main body case 1 and the hub In the tape cartridge, a separate sheet 10 having a through hole 12 corresponding to the drive shaft insertion hole 2 is interposed between the tape cartridge 4 and the drive shaft insertion hole 2. The protrusions 13 and 13 are formed to protrude toward the seat back surface 10b, and the distance l between the protrusions 13 and 13 is larger than the diameter d of the through hole 12 and larger than the outer diameter D of the hub 4. The surface of the sheet surface 10a has a 10-point average roughness Rz.
It has been mirror-finished to have a thickness of 1.0 μm or less, and both protrusions 13 are in contact with the inner wall of the case, and the convexly curved sheet surface 10a side is in elastic contact with the hub 4 and tape 3. Features a tape cartridge.