JPS593421Y2 - tape cassette - Google Patents

Description

[Detailed description of the invention] The present invention places a tape guide between a pair of upper and lower tape guide attachment parts that are integrally provided on the upper and lower cassette halves, and inserts a pair of upper and lower screws into the pair of upper and lower tape guide attachment parts. The present invention relates to a tape cassette in which the tape guide is screwed to the upper and lower cassette halves by screwing them from above and below into a pair of upper and lower screw holes provided at both upper and lower ends of the tape guide.

FIG. 1 shows an example of a conventional tape cassette for this type of VTR. For example, three cylindrical tape guides 3 made of metal such as stainless steel are arranged on both the left and right sides of the front opening 5 of the tape cassette 1. Upper and lower cassette half 1
They are screwed to a and lb respectively.

That is, the upper and lower cassette halves 1a and lb of the tape cassette 1
A pair of tape guide mounting portions 7 and 8 are each integrally provided in the , and as shown in FIG. Upper and lower cassette halves 1a, 1b by 10
Tightening is fixed from above and below.

As shown in FIG. 2, screw holes 12 having the same diameter are provided at both ends of the tape guide 3, and each screw hole 12 is provided with a tapped screw.

Then, as shown in FIG. 2, the screw 1 is inserted into the screw hole 12.
When screwing the tape guide 3 to the tape guide attachment parts 7 and 8 of the upper and lower cassette halves 1a and lb by screwing in the screw holes 12, the screws 10 that are screwed into these screw holes 12 are usually tightened within the effective length. (The length of the portion where the screw 10 and the screw hole 12 substantially engage with each other:
(corresponding to 1 in FIG. 2) are equal to each other, the engagement forces of the pair of upper and lower screws 10 to the screw holes 12 are equal to each other.

By the way, in a tape cassette for a VTR, a front cover 14 is attached to the upper cassette half 1a and is rotatable about a hinge part 15 and has an L-shaped cross section.
Normally, this front cover 14 closes the front opening 5 of the tape cassette 1 as shown by the solid line in FIG. The lid can be opened as shown in the imaginary line.

In this open state, the front cover 14 is no longer rotated counterclockwise in FIG. 2.

Such a tape cassette for a VTR is assembled using the following procedure.

That is, first, attach one side of the tape guide 3 to the upper cassette half 1.
It is fixed to the tape guide attachment part 7 of a with a set screw 10, and then the hinge part 15 of the front cover 14 is attached to the upper cassette half 1a side.

Then, a supply reel and a take-up reel (not shown) to which one end of the tape is fixed are attached to, for example, the lower cassette half 1.
Finally, the upper and lower cassette halves 1a and 1b are assembled and the other end of the tape guide 3 is attached to the tape guide mounting portion 8 of the lower cassette half 1b with the set screw 10.
Fasten with screws.

In this case, the tape between the supply reel and the take-up reel is guided by three tape guides 3 and arranged so as to be swiped along the front opening 5 of the tape cassette 1.

Although the tape cassette 1 is assembled as described above,
After the front cover 14 is attached to the upper cassette half 1a side of the tape cassette 1, even if the front cover 14 is opened, the upper part of the set screw 10 on the upper cassette half 1a side will not remain as shown by the imaginary line in FIG. It is always covered by this front lid 14.

Therefore, if a defect in the tape or the like is found after completing the assembly of the tape cassette 1, open the front cover 14 slightly, loosen the set screws 10 on the lower cassette half 1b side, and remove the tape. The cassette 1 must be separately disassembled into upper and lower cassette halves 1a and lb.

At that time, screw holes 1 provided at both ends of the tape guide 3
Since the engagement forces of the pair of upper and lower set screws 10 on the lower cassette half 1b side are equal, there is a risk that the set screw 10 on the upper cassette half 1a side will loosen due to the screw return torque when the set screw 10 on the lower cassette half 1b side is loosened. Most likely.

If the set screw 10 on the upper cassette half 1a side becomes loose, remove the set screw 10 on the upper cassette half 1a side.
However, as mentioned above, if the front cover 14 is attached to the upper cassette half 1a during the assembly process of the tape cassette 1, the front cover 14 will not tighten as shown in FIG. Since the upper part of the screw 10 is covered, it is not possible to insert a screwdriver or the like into the head of the screw 10 and retighten the screw 10.

Therefore, in such a case, after disassembling the tape cassette 1 into upper and lower cassette halves 1a and 1b separately, remove the front cover 14 from the upper cassette half 1a, and then tighten the set screws 10 on the upper cassette half 1a side. This has to be repaired, and the work efficiency in the process of assembling the tape cassette 1 is greatly reduced.

The present invention was devised to solve the above-mentioned inconveniences, and in the tape cassette mentioned at the beginning,
Either the upper and lower pair of screw holes and the upper and lower set screws are tightened to have different effective diameters, or the upper and lower set screws are tightened to the upper and lower pair of screw holes so that the effective length is different. The present invention relates to a tape cassette characterized in that the tape cassettes are different from each other.

With this configuration, only the stop screw on one side can be easily removed without unexpectedly loosening the stop screw on the other side.

Therefore, there is no possibility that work efficiency will be hindered in the tape cassette assembly process.

An embodiment of a tape cassette for a VTR to which the present invention is applied will be described below with reference to FIGS. 3 and 4.

Note that parts common to those in FIG. 2 are designated by common reference numerals, and their explanations will be omitted.

FIG. 3 shows a first embodiment of the present invention, in which screw holes 1B and 19 having different inner diameters are provided at both ends of a tape guide 20 of a tape cassette 17, respectively. .

Of both ends of the tape guide 20, the end with the larger inner diameter is attached to the tape guide attachment part 7 of the upper cassette half 17a with a tapping screw 21, and the end with the smaller inner diameter is attached to the tape guide of the lower cassette half 17b. It is attached to the attachment part 8 with tapping screws 22.

Note that the effective thread length of the above-mentioned tapping screw 22 (L in Fig. 3)
1) are configured equally to each other.

Further, this tape guide 20 is made of synthetic resin in order to significantly reduce the cost of device parts.

When the tape guide 20 is installed as described above, there is a difference in the inner diameter of the screw holes 1B and 19, and the upper cassette half 17
The effective diameter of the screw hole 18 and the tapping screw 21 on the side a is larger than the effective diameter of the screw hole 19 and the tapping screw 22 on the lower cassette half 17b side. The screw return torque required to loosen the tapping screw 22 is relatively smaller than the screw return torque required to loosen the tapping screw 21 on the upper cassette half 17a side.

Therefore, even if the tapping screws 22 on the lower cassette No. 717b side are loosened after the tape cassette 17 is assembled, the tapping screws 21 on the upper cassette No. 1-No. 1-717a side will not loosen.

Therefore, there is no need to re-tighten the end of the tape guide 20 that has been tightened once on the upper cassette half 717a side, and only the self-tapping screw 22 on the lower cassette half 17b side can be tightened. It can be loosened and removed.

Therefore, in the process of assembling the tape cassette 17, even if it has to be disassembled into the upper and lower cassette halves 17a and 17b separately, the process can be carried out efficiently without causing any major hindrance to work efficiency.

Furthermore, since the tape guide 20 is made of synthetic resin, the cost of this component can be significantly reduced.

FIG. 4 shows a second embodiment of the present invention.

In this example, screw holes 26 and 27 having the same inner diameter are provided at both ends of the tape guide 24 made of synthetic resin, and a hollowed recess 29 is formed in one of the screw holes 27. ing.

Of both ends of the tape guide 24, the end where the screw hole 26 is provided is attached to the tape guide attachment part 7 of the upper cassette half 17a, and the end where the screw hole 27 is provided is attached to the bottom. Tapping screws 31.3 having the same dimensions are attached to the tape guide mounting portion 8 of the cassette half 17b.
It is fixed with screws 2.

In this case, the effective length L2 for tightening the screw holes 26 and the tapping screws 31 on the upper cassette half 17a side is longer than the effective length L3 for tightening the screw holes 27 and the tapping screws 32 on the lower cassette half 17b side. long.

Therefore, the screw return torque required to loosen the tapping screw 32 is the tapping screw 31 on the upper cassette half 17a side.
This is smaller than the screw return torque required to loosen the
Even if the tapping screw 32 is loosened, the tapping screw 31 will not be loosened.

Therefore, according to the tape cassette 17 of this example, it is possible to easily loosen and remove only the tapping screw 32 on the side of the lower cassette half 17b.

Although the present invention has been described above with reference to embodiments, the present invention is not limited to these embodiments and can be modified in various ways. The structure may be such that there is a substantial difference in the resultant force.

As described above, the present invention makes the effective diameters of the screw hole and the set screw different, or makes the effective length of the set screw different when tightening the set screw to the screw hole. By creating a difference in engagement force, the structure creates a difference in the screw return torque at both ends of the tape guide, so it is easy to tighten only one set screw without loosening the other set screw. can be removed.

Therefore, even if it is necessary to separately disassemble the tape cassette into upper and lower cassette halves after the assembly of the tape cassette is completed, this disassembly can be done without adversely affecting other parts. There is no possibility of any major hindrance to work efficiency in the assembly process.

[Brief explanation of the drawing]

1 and 2 show a conventional tape cassette for a VTR, in which FIG. 1 is a perspective view of the tape cassette, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. The figure is a sectional view similar to Figure 2 showing the first embodiment in which the present invention is applied to a tape cassette for a VTR, and Figure 4 is a sectional view similar to Figure 2 showing the first embodiment in which the present invention is applied to a tape cassette for a VTR.
A second example showing a second embodiment applied to a tape cassette for
It is a sectional view similar to the figure. In addition, in the symbols used in the drawings, 17...
...Tape cassette, 18.19...screw hole,
20...Tape guide, 21.22...
・Tapping screw, 24...Tape guide, 26
．． 27... Screw hole, 31.32... Tapping screw, 7, 8... Tape guide mounting part,
17a, 17b... Upper and lower cassette halves.

Claims (1)

[Scope of utility model registration request] A tape guide is arranged between a pair of upper and lower tape guide attachment parts that are integrally provided on the upper and lower cassette halves, and a pair of upper and lower screws are passed through the pair of upper and lower tape guide attachment parts, respectively, to attach the tape guide to both upper and lower ends. In the tape cassette, the tape guide is fixed to the upper and lower cassette halves with screws by screwing from above and below into a pair of upper and lower screw holes provided in the upper and lower parts. The invention is characterized in that the effective diameters of the screws are made to be different when tightening the screws with the screws, or the effective lengths of the pair of screws when the screws are tightened to the pair of upper and lower screw holes are made to be different from each other. tape cassette.