JPH0441506Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] For example, in a video tape cartridge as shown in the attached drawing, tape reels 3, 3 on which tape 2 is wound on the left and right sides inside the main body case 1 are rotatable. A reel presser plate spring 7 is supported on the inner surface of the upper wall 9 of the main body case 1, and the plate spring 7 presses the center of rotation of each tape reel 3 downward.

The present invention is a tape cartridge equipped with this type of reel presser leaf spring 7, in which the shape of the leaf spring 7 is uniquely improved.

[Conventional technology]

As a typical conventional reel presser plate spring 7,
For example, a stainless steel plate is cut out into a horizontally elongated rhombus shape, the wide supporting portion 7a at the center of the left and right sides is supported and fixed to the case upper wall 9, and the first arm portions 7b, 7b are extended downward from the left and right sides of the supporting portion 7a. It comes out in succession.
The rotation center of each tape reel 3, 3 is elastically biased downward at the free end side of the first arm portions 7b, 7b.

In such a conventional reel presser plate spring 7, regardless of whether its overall shape is diamond-shaped, U-shaped, or V-shaped, the effective span of the first arm portion 7b is long to ensure a predetermined initial spring pressure. To press the tape reel 3 downward without wobbling even when not in use (in a state where the tape reel 3 is received and supported by the bottom wall of the main body case 1). In particular, when the tape cartridge is mounted on a deck and the drive shaft on the deck side engages with the hub portion 5 of each tape reel 3 to push up the entire tape reel 3,
The plate springs 7 press down each tape reel 3 with a larger pressing force to improve the stability of tape running.

[Problem to be solved by the invention] However, since the conventional reel presser plate spring 7 has a shape in which the spring constant is constant over the entire length of the first arm portion 7b, looking at its deflection-load characteristics, Becomes a straight line. Therefore, if an attempt is made to ensure a necessary and sufficient load in the use state, the load (initial spring pressure) in the non-use state also tends to increase.

Therefore, even when the case is not in use, a strong reaction force from the reel presser plate spring 7 acts on the case top wall 9, and the corresponding portion of the case top wall 9 is always pressed upward. As a result, if the tape cartridge is left in a high-temperature atmosphere for a long time, the portion of the upper wall 9 of the case, which is a resin molded product, corresponding to the leaf spring support portion 7a will swell upward as shown in FIG. Not only does this seriously impair the appearance, but it also causes functional problems such as fluctuations in spring pressure. In an even more extreme case, as shown in FIG.
A gap g is created on the back side between b and there is a problem such as dust entering into the main body case 1 through the gap g.

These conventional problems can be solved by making the top wall 9 of the case thinner by making the tape cartridge smaller.
In an embodiment in which a large transparent window 12 is formed on the case top wall 9 to visually check the amount of tape wound on the tape reel 3, and the support portion 7a of the leaf spring 7 is supported and fixed at the center of the case top wall 9, It tends to appear.

Originally, the above-mentioned problems could be solved by reducing the elastic force of the leaf spring 7 against the tape reel 3, that is, the spring constant, as much as possible. However, when the leaf spring 7 has a constant spring constant, there are restrictions in securing the desired elastic force to the tape reel 3 during use, and the spring constant of the leaf spring 7 cannot be reduced below a certain value. However, this has become a problem in the conventional case.

[Purpose of invention]

The present invention was proposed in order to eliminate such conventional problems, and by reducing the elastic force of the reel presser plate spring 7 when it is not in use, the case upper wall 9 can be easily maintained even if left in a high-temperature atmosphere for a long time. The purpose is to prevent deformation from occurring.

Furthermore, the purpose is to ensure the necessary and sufficient elastic force of the leaf spring 7 against the tape reel 3 during use, thereby ensuring stable rotation of the tape reel 3 and, ultimately, stability of tape running.

[Means for solving problems]

In the present invention, as shown in FIGS. 4 and 5, a reel presser plate spring 7 is attached to the inner surface of the upper wall 9 of the main body case 1.
is supported and fixed, and the tape reel 3 mounted in the main body case 1 is pressed downward by the free end of the first arm 7b extending downwardly from the support part 7a of the leaf spring 7. A tape cartridge is a prerequisite.

In that case, the reel presser leaf spring 7 is not limited to a rhombic shape in plan view, but may be U-shaped or V-shaped, or two leaf springs 7 are placed on the left and right sides of the inner surface of the case upper wall 9. , 7's proximal support parts 7a, 7a
Each first arm portion 7 supports individually and extends in a cantilevered manner.
The present invention also deals with a tape cartridge in which the left and right tape reels 3, 3 are independently pushed down and biased by the free ends 7e, 7e of b, 7b.

In addition, in the present invention, as shown in FIGS. 1 and 2 a and b, a second arm 7c is cut and raised at a predetermined upward angle θ at a suitable intermediate portion of the first arm 7b, When the second arm part 7c is not in use, the upper end part 7d of the second arm part 7c is close to the case upper wall 9 in a non-contact state as shown by the solid line in FIG.
It is required that the upper end portion 7d is received and supported by the upper wall 9 of the case during use when it is bent and deformed.

Here, it is preferable that the second arm portion 7c is cut upward toward the support portion 7a as shown in the illustrated example, but the present invention is not limited thereto.
From the middle front and back edges of the first arm 7b to the second arm 7c
It may be formed by cutting.

[Effect]

Now, as shown in FIG. 1 and FIG. 2a, the reel presser plate spring 7 is supported on the upper case 1a, and the free end 7e when no load is applied to the first arm 7b and the second arm 7c. The free height is l (mm), and the upper end 7d of the second arm 7c is close to the case upper wall 9 in the assembled state in which the tape reel 3 is stored in the main case 1 as shown in FIG. Let the amount of upward deflection of the free end 7e be l ₁ (mm), and let the amount of deflection of the free end 7e during use when the upper end 7d is in elastic contact with the case upper wall 9 be l ₂ (mm). do.
Further, the spring constant of the first arm 7b is k ₁ (g/mm), the spring constant of the second arm 7c is k ₂ (g/mm), and the spring constant of the conventional plate spring 7 is k ₃ (g/mm). g/mm).

Thus, if the elastic force of the plate spring 7 of the present invention when in use is the same as that of the conventional example, these load-deflection diagrams will be as shown in FIG. Deflection amount of spring 7
During the transition from l ₁ ) to use (deflection amount l ₂ of leaf spring 7), the spring constant increases from k ₁ to k ₁ +k ₂ , resulting in a polygonal shape. In contrast, in the conventional example, the spring constant
Since k ₃ is constant, it becomes a straight line. The vertical axis in FIG. 3 represents the load f(x) [g] and g(x) [g] acting on the leaf spring 7 of the present invention and the conventional leaf spring 7, and the horizontal axis represents the amount of deflection x (mm ) is shown.

As is clear from FIG. 3, in the case of the present invention, the load acting on the leaf spring 7 when not in use can be reduced compared to the conventional example. More specifically, as shown in Figure 3, from α(g) to β
(g). Therefore, in the present invention, the elastic force of the leaf spring 7 when in use is maintained the same as that of the conventional example, and the elastic force of the leaf spring 7 when not in use is maintained.
The reaction force against the upper wall 9 can be reduced as much as possible.

[Effect of idea]

Therefore, according to the present invention having the above configuration, the reaction force applied from the reel presser plate spring 7 to the upper wall 9 of the main body case 1 when not in use can be reduced as much as possible compared to the conventional example. Therefore, it is possible to reliably eliminate problems such as swelling of the main body case 1 even if it is left in a high-temperature atmosphere for a long time. Furthermore, during use, the elastic force of the leaf spring 7 against the tape reel 3 can be ensured as desired, comparable to the conventional example, so that stable rotation of the tape reel 3 and stability of tape running can be achieved.

〔Example〕

The drawing shows a video tape cartridge, which is an example of a tape cartridge to which the present invention is directed.

To explain the overall structure of this device, as shown in FIGS. 4 and 5, the main body case 1 of this device is formed by screwing together upper and lower plastic cases 1a and 1b such that their lids fit together. A pair of tape reels 3, 3 on which the tape 2 is wound are rotatably housed inside the main body case 1 on the left and right sides. The tape 2 is fed out from one tape reel 3 to the front of the case and wound onto the other tape reel 3.

Each tape reel 3 has a central hub part 5 and a lower flange 6a integrally molded from plastic, and a separate upper flange 6b molded from transparent plastic material which is integrally joined to the upper surface of the hub part 5 by ultrasonic welding. Become.

A reel presser plate spring 7 is supported at the center of the inner surface of the upper wall 9 of the main body case 1, that is, the inner wall surface of the upper case 1a.

The reel presser plate spring 7 is made of a stainless steel plate and is formed into a substantially rhombic shape that is elongated from side to side.
It has first arm portions 7b, 7b extending from both the left and right ends and tilting downward toward the free end. As shown in FIGS. 2a and 2b, a second arm 7c is provided at the front and rear center portions of each first arm 7b in the middle in the left-right direction, and is oriented upward by a certain angle θ toward the supporting portion 7a. This second arm portion 7 is cut and raised.
The upper end 7d of c is horizontally bent.

The support part 7a is caulked and fixed to the case upper wall 9, and as shown in FIG. The protrusions 11, 11 provided thereon are brought into elastic contact with each other, thereby constantly pressing down and biasing each tape reel 3, 3. At this time, the second arm portion 7c
When not in use, the upper end 7d is close to the inner surface of the case upper wall 9 in a non-contact manner, as shown by the solid line in FIG. When the tape cartridge is loaded onto a deck and used, the tape reels 3, 3 are pushed up, and the first arms 7b, 7b are bent and deformed in a substantially horizontal manner, and the second arms 7c, 7c are pushed against the case upper wall 9. The first and second arm portions 7b and 7c work together to press down and bias each tape reel 3.

The case upper wall 9 has transparent windows 12, 12 on the left and right sides of the central portion, and the amount of tape wound on each of the left and right tape reels 3, 3 can be visually confirmed from the outside through the transparent windows 12, 12. That is, each transparent window 12 is formed by providing a window 13 in the upper wall 9 of the case, and integrally fixing a transparent plate 14 made of transparent plastic that closes the window 13 to the inner surface of the upper wall 9 of the case.
Thus, the reel presser plate spring 7 has the first arm portion 7b,
Only the free ends 7e and 7e of 7b are left and right transparent windows 1
I am facing the 2nd and 12th.

[Brief explanation of the drawing]

Fig. 1 is an enlarged longitudinal cross-sectional side view of the main parts to explain the deflection state when the reel presser plate spring is assembled;
Figure a is a side view of the reel presser plate spring in its free state, and Figure 2b is its plan view. FIG. 3 is a graph showing the relationship between the load and the amount of deflection of the reel presser plate spring. FIG. 4 is an external perspective view of a tape cartridge to which the present invention is directed, and FIG. 5 is a front view in longitudinal section of the tape cartridge. FIGS. 6 and 7 show a conventional tape cartridge, with FIG. 6 being a longitudinal sectional front view and FIG. 7 being a rear view illustrating a defective state. DESCRIPTION OF SYMBOLS 1... Main body case, 2... Tape, 3... Tape reel, 7... Reel presser plate spring, 7a... Support part, 7b... First arm part, 7c... Second arm part, 7
d... Upper end of the second arm, 7e... Free end of the first arm, 9... Upper wall of the main case.

Claims (1)

[Claims for Utility Model Registration] A support portion 7a supported on the inner surface of the upper wall 9 of the main body case 1, and a first arm portion extending integrally from the support portion 7a so as to be inclined downward toward the distal end side. In a tape cartridge having a reel presser plate spring 7 having a reel presser plate spring 7b, the tape reel 3 housed in the main body case 1 is pressed downward at the free end side of the first arm portion 7b. A second arm portion 7c is formed by cutting and raising the second arm portion 7c upward at the middle portion of the first arm portion 7b of the spring 7, and when not in use, the upper end portion 7d of the second arm portion 7c does not contact the inner surface of the upper wall 9. When the first arm 7b is bent and deformed, the second
A tape cartridge characterized in that an upper end portion 7d of the arm portion 7c is received and supported by the inner surface of the upper wall 9.