JPS5843105Y2 - Tape clamp structure for magnetic tape cartridge hub - Google Patents

Description

[Detailed Description of the Invention] This invention is an improvement to the tape clamp structure for connecting and fixing the end of a magnetic tape to a bubble built into a magnetic tape cartridge.

In a magnetic tape cartridge as shown in FIG. 1, a pair of plastic bubbles 33 are installed inside the main body case, and an end of the magnetic tape 4 (usually the end of the leader tape) is engaged with each of the bubbles 3. I stop and wind it, but this Bab 3
There was a problem with the tape clamp structure.

In other words, the typical conventional tape clamp structure is
Examples include those shown in FIG.

This is done by forcibly pressing the cylindrical clamp bin 9a into the inwardly expanding fitting hole 11 formed in one place on the outer peripheral surface of the bub 3, with the tape end sandwiched between the clamp bin 9a and the fitting hole 11.
This structure utilizes the elastic deformation of the tape to hold the ends of the tape.

When this is done, it is necessary to form the left and right opening edges of the fitting hole 11 into tapered guide surfaces 25 that taper inward in order to allow press-fitting of the clamp bin 9a, and the surface of the clamp bin 9a. In addition to the fact that the curvature is significantly different from that of the outer peripheral surface of the bub, a large gap 26 is created between the opening edge of the fitting hole 11 and the clamp bin 9a.

Therefore, when the magnetic tape 4 is wound around the bubble 3, the magnetic tape 4 covers the entire width of the gap 26 at the beginning of winding.
It penetrates into the tape and causes wrinkles, which spreads and becomes one of the causes of uneven winding between tape layers.

Furthermore, even after clamping, the end 4a of the magnetic tape 4 protrudes onto the outer circumferential surface of the tape 3, increasing tape winding irregularities.

Therefore, as shown in FIG. 9, a three-pronged clamp piece 9b whose surface has the same curvature as the outer circumferential surface of the bubble is conventionally used, and this is force-fitted into the fitting hole 11 of the bubble 3 by sandwiching the tape end. The method is also widely adopted.

However, since the clamp piece 9b is forcibly press-fitted into the fitting hole 11 in this case as well, a gap 26 still occurs at the opening edge 14 of the fitting hole 11.

In addition, as is the case with the clamp bin 9a described above, the clamp piece 9b itself has a particularly large amount of elastic deformation, so it deteriorates and becomes fatigued due to temperature conditions and repeated tape tension, causing damage to the piece 9b. The tape clamping function deteriorates over time, and in the worst case, the magnetic tape 4 may be ejected.

These conventional drawbacks arise not only from the shape of the clamp piece but also from the fact that the clamp piece is elastically deformed and forced into the fitting hole of the knob.

Focusing on this fact, this invention loosely fits the clamp piece into the fitting hole of the hub with the tape end sandwiched between the L
Afterwards, a press-fit pin is forcibly inserted into a through-hole formed in the clamp piece in the fitting hole, and the clamp piece is elastically deformed to clamp the tape end in the fitting hole, thereby eliminating the conventional method. The aim is to eliminate all of the shortcomings of

The details will be explained below based on the drawings.

FIG. 1 illustrates a standard Philips type magnetic tape cartridge.

The main case 1 of this is the upper and lower plastic cases 1a.
, 1b are screwed together in a lid-like manner, and have drive shaft insertion holes 2, 2 on the left and right sides of the center, and polyacecool resin knobs 3, 3 are rotatably mounted on each of these insertion holes 2, 2. It's decorated inside.

Then, both ends (leader tape portions) of the magnetic tape 40 are connected and fixed to each knob 3, 3, and wound, and this magnetic tape 4 is fed out from one supply side hub 3 and placed in the main body case 1.
The tape travels through an erasing head insertion port 5, a recording/reproduction magnetic head insertion port 6, and a pinch roller insertion port T, which are opened in the front surface of the disk, in order, and is wound onto the other winding-side hub 3.

In FIG. 2, the end of the magnetic tape 4 is connected and fixed to the hub 3 via a clamp piece 9 and a press-fit pin 10, and these constituent members are as follows.

In FIGS. 3, 4, and 5, the hub 3 has a fitting hole 11 at one location on its outer peripheral surface.

This fitting hole 11 is recessed across the width direction of the hub 3, the inner bottom surface 12 is concavely curved, and the left and right opposing side surfaces 13, 13 are undercut (concave) in the upper part near the left and right opening edges 14, 14.
It is formed in a vertical plane having 15,15.

Incidentally, the left and right opening edges 14, 14 form rounded surfaces with a radius of approximately 0.2 mm, and the depth h of the fitting hole 11 is approximately 3.2 mm.

Then, the left and right vertical surfaces 13 above the undercut 15
Width W1 of a, 13a is approximately 3.05 mm, undercut 1
The width W2 between the left and right vertical surfaces 13b, 13b inwardly from 5 is about 3.31 m, and it is formed to expand slightly inward.

In FIGS. 2 and 5, the clamp piece 9 is made of polyethylene resin with good elastic deformation, and its surface 16
is formed to have the same curvature as the outer peripheral surface 17 of the hub 3, and the lower surface 18
is in an open state.

Concave grooves 19, 19 are formed in the left and right upper portions in the front-rear direction, and a vertically elongated through hole 20 is transparently provided in the center of the lower part of the grooves 19, 19 in the front-rear direction.

The left and right side surfaces thereof have a vertical surface 21a above the groove 19 and a tapered surface 21b below.

Incidentally, its dimensions are that the vertical height H is approximately 3.0+i+, the left and right maximum width W, that is, between the vertical surfaces 21a, 21a is approximately 3.0 mm, and the short axis d1 of the through hole 20 is approximately 1.2 mm. Long diameter d2
is set to about 1.9.

Further, the longitudinal length of the hub 30 is approximately 3.91 m since the longitudinal width of the hub 30 is 3.95 Im.

In FIG. 2, the press-fitting bottle 10 is made of polyacetal resin and has a solid cylindrical shape with tapered guide surfaces 22, 22 at both ends, which is harder than the clamp piece 9 and less likely to deform.

Incidentally, its dimensions are: length t is approximately 3.7ml, diameter DI at the center is approximately 1.7i+it, diameter D2 at the tip is approximately 1,
Q tnn is set.

When connecting and fixing the end of the magnetic tape 4 to the hub 3 using these components, as shown in FIG. Fits into the fitting hole 11.

As mentioned above, the clamp piece 9 is dimensionally smaller overall than the fitting hole 11, and the lower surface 18 is open, so even if the magnetic tape 4 is interposed in the fitting hole, the clamp piece 9 can be smoothly fitted into the fitting hole. 11.

Next, press fit the pin 10 into the through hole 20 of the clamp piece 9.
Forcibly press in.

Since the tip of the press-fit pin 10 is formed on the tapered guide surface 22, it is smoothly guided and fitted into the through hole 20.

Since the diameter D1 of the press-fitting pin 10 is smaller than the short diameter d1 of the through-hole 20, when the press-fitting pin 10 is forcibly press-fitted into the through-hole 20, the lower half of the clamp beef 9 is elastically deformed within the fitting hole 11. Then, the end of the magnetic tape 4 is sandwiched and crimped onto the inner wall surface of the fitting hole 11, resulting in the state shown in FIGS. 6 and 1.

At this time, the elastic deformation of the lower half of the piece is effectively absorbed by the oval through hole 20 and the left and right grooves 19° 19 on the surface of the piece.

Therefore, the piece surface 16 is maintained flush with the bubble outer peripheral surface 11 and at the same curvature.

In addition, the opening edge 14°1 of the crank piece 9 and the fitting hole 11
4, the vertical surfaces 13a and 21a of both are joined to each other, creating only a predetermined extremely small gap,
Due to the contact between the vertical surfaces 13a and 21a, the press-fit pin 1
Clamp piece 9 is inserted inside fitting hole 11 during press-fitting work of 0.
Insects are prevented from causing misalignment.

In addition, there are undercuts H5, 15 inside the fitting hole 11, and the opening edges 14, 14 of the fitting hole 11 are formed with a slight rounded surface, so that the edge of the magnetic tape 4 fits into the fitting hole. It does not protrude into the outer surface of 11.

Furthermore, since the vertical height H of the clamp piece 9 is set to be slightly smaller than the depth h of the fitting hole 11, the sixth
As shown in the figure, when the clamp piece 9 is pushed into the fitting hole 11 with the pusher 23 and fitted, the actual open lower surface 1 of the piece 9
8 does not contact the concave inner bottom surface 12 of the fitting hole 11.

Therefore, if the press-fitting pin 10 is press-fitted while holding the clamp piece 9 with the pusher 23, the surface 16 of the piece 9
is flush with the knob without protruding from the outer peripheral surface 17,
The open lower surface 18 of the piece 9 is elastically deformed by the press-fitting pin 10 and comes into contact with the concave inner bottom surface 12 of the fitting hole 11.

It is also expected that the central thin portion of the lower surface 18 of the piece 9 will be torn by the press-fitting of the press-fitting pin 10 and will be pressed into contact with the inner bottom surface 12 of the fitting hole 11 as shown in the figure.

Although the illustrated example is as described above, the shapes of the fitting hole 11 and the clamp piece 9 can be freely changed as long as the clamp piece 9 can be fitted into the fitting hole 11 without forcibly deforming the clamp piece 9. Design can be changed.

For example, the left and right opposing side surfaces 13° 13 of the fitting hole 11 may be formed into tapered surfaces that widen inward from the opening edges 14, 14.

In addition, the lower half of the clamp piece 9 is provided with a through hole 20 from the outer periphery so that it can be easily elastically deformed by press-fitting the press-fitting pin 10.
A notch may be formed in advance.

Further, the tapered guide surface 22 may be formed on the through hole 20 side.

As explained above, according to this invention, after the clamp piece 9 is fitted into the fitting hole 11 formed in the buff 3 with the end of the magnetic tape 4 sandwiched therebetween, the clamp piece 9 is press-fitted into the through hole 20 of the piece 9. The pin 10 is press-fitted, and the piece 9 is elastically deformed at this stage, so that the magnetic tape 4 is crimped and clamped on the inner wall surface of the fitting hole 11.

Therefore, unlike the conventional structure in which the clamp piece 9 is force-fitted into the fitting hole 11 while being elastically deformed, the clamp piece 9 is press-fitted into the fitting hole 11.
Since the shape of the piece 9 and the shape of the piece 9 can be set easily, it is possible to prevent gaps or steps from forming between the opening edges 14, 14 of the fitting hole 11 and the piece 9 as much as possible.

Furthermore, it is possible to prevent the edge of the magnetic tape 4 from protruding into the outer periphery of the bubble.

Furthermore, since the surface 16 of the piece 9 can be well maintained to have the same curvature as the outer circumferential surface 11 of the bubble, together with this, it is possible to eliminate uneven winding between the magnetic tape layers wound around the bubble 3.

In addition, the piece 9 that is elastically deformed by the press-fit pin 10 is different from a piece made by a single piece, and since the press-fit pin 10 is interposed, it is possible to reliably prevent the tape clamping function from deteriorating over time, and it can be used for a long period of time. There is no risk that the magnetic tape 4 will be pulled out from the bubble 3 even if it is used for a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a cutaway plan view of a magnetic tape cartridge to which this invention is applied, and Fig. 2 is a perspective view showing the constituent members of this invention, such as a bub, a clamp piece, and a press-fit pin.
Figure 3 is a front view of the bubble, Figure 4 is A-A in Figure 3.
Line sectional view, Figure 5 is a front view comparing the bubble and clamp piece, Figure 6 is a front view of the main part showing the tape clamp structure, Figure 1 is a BB line cross section in Figure 6. It is a diagram. FIG. 8 and FIG. 9 are front views of main parts showing different conventional tape clamp structures, respectively. 3...Bub, 4...Magnetic tape, 9.
... Clamp piece, 10 ... Press fit pin, 11 ... Fitting hole, 12 ... Inner bottom surface of 11, 13 ... ... 11 Left and right opposing surfaces, 14.
...11 opening edge, 15...undercut, 16...9 surface, 17...3
Outer surface of 18...9, bottom surface of 19...
・Concave groove, 20... Through hole, 22...
Tapered guide surface.

Claims (1)

[Scope of utility model registration request] A plastic bub 3 has a fitting hole 11 that expands inward at one location on the outer circumferential surface and is recessed in the front and rear width directions, and the surface 16 is formed to have the same curvature as the outer circumferential surface IT of the bubble 3 and extends in the front and rear direction. It consists of an elastically deformable plastic clamp piece 9 with a through-hole 20 formed therein, and a press-fitting pin 10 having a diameter larger than that of the through-hole 20. After fitting the clamp piece 9 across the ends of the magnetic tape 4, the press-fitting bottle 10 is press-fitted into the through hole 20 via the tapered guide surface 22 formed on either one of the magnetic tape 4. A tape clamp structure for a magnetic tape cartridge bub in which the end portion is crimped and locked between a fitting hole 11 and a clamp piece 9 in a manner that prevents it from coming off.