JPH0525112Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a reel support shaft fixing mechanism, and in particular,
The present invention relates to a reel support shaft fixing mechanism suitable for application to a support shaft that supports the reel of a VHS-C (registered trademark) video tape cassette or the like.

[Conventional technology]

In the following description, an example in which the present invention is applied to a support shaft that supports a reel of a VHS-C video tape cassette will be described. FIGS. 6 and 7 are vertical sectional views showing a conventional example of a reel support shaft fixing mechanism together with other components near the reel support shaft of a tape cassette. In both figures, 1 is a casing (cassette half; hereinafter also simply referred to as "half");
2 is a reel support shaft (hereinafter also simply referred to as "support shaft"); 3 is a pin for fixing the support shaft 2 to the half 1; 4 is a reel around which magnetic tape (not shown) is wound; 5 is a reel This is a cylindrical hole bored inside the support shaft 2. The support shaft 2 itself is approximately cylindrical, and its cross-sectional diameter is approximately equal to the inner diameter of the cylindrical hole 4a provided in the center of the reel 4 (that is, there is almost no gap), and the rotation of the reel 4 It is formed with high precision to dimensions that do not interfere with In the example of FIG. 6, this support shaft 2 is connected to the cylindrical hole 5.
A screw thread 5a is formed on the inner wall of the cylindrical hole 5, and a pin 3 having a threaded portion 6 on the side surface is screwed into the thread thread 5a of the cylindrical hole 5, thereby fixing the pin 3. In the example shown in FIG. 7, the pin 3 is press-fitted into the cylindrical hole 5 for fixation.

[Problem that the invention attempts to solve]

In all of the conventional reel support shaft fixing mechanisms as described above, a cylindrical hole 5 is provided inside the support shaft 2.
The support shaft 2 is fixed to the half 1 by screwing or press-fitting the pin 3 there. Therefore, the inner diameter of the cylindrical hole 5 and the kerf depth of the threaded thread 5a must be formed with very high precision. If it is even slightly too large, the fit will become loose and the support shaft 2 cannot be fixed firmly enough to the half 1. On the other hand, if it is too small, the cylindrical hole 5 (and thus the support There was a drawback in that the shaft 2) expanded and prevented the smooth rotation of the reel 4, and furthermore, this caused a serious hindrance to tape running.
Furthermore, even if the inner diameter of the cylindrical hole 5 and the depth of the groove of the threaded thread 5a are formed correctly with very high precision, the above-mentioned defects still occur due to variations in the thickness of the pin 3. There was a problem with this.

[Means for solving problems]

The present invention provides a reel support shaft fixing mechanism in which a hole is drilled at a predetermined location in the housing and a reel support shaft is fixed to the hole. (press-fit part) is formed from the outside of the casing into this shaft part, and the inside diameter is slightly smaller than the diameter of the shaft part, or is formed into a wedge shape with a slight slope, and the part that abuts the casing. The above-mentioned problems have been successfully solved by fixing the support shaft by press-fitting a ring member with a shape that increases the frictional force during connection to a position where it contacts the housing. It is.

〔Example〕

An embodiment of the reel support shaft fixing mechanism of the present invention will be described with reference to FIG. 1 and subsequent figures. 1 to 3 are partially sectional side views of first to third embodiments of the reel support shaft fixing mechanism of the present invention, respectively.
In these figures, the same components as those in the conventional example shown in FIGS. 6 and 7 are given the same reference numerals, and detailed explanation thereof will be omitted. These figures 1 to 3
As shown in the figure, in the reel support shaft fixing mechanism of the present invention, instead of providing a cylindrical hole in the support shaft 12, a hole is bored in the lower part of the support shaft 12 at a predetermined position of the half 1. A shaft portion 13 is formed extending from the shaft portion 11 to the outside of the half 1, and a ring member 14 is press-fitted into the shaft portion 13 from the outside of the half 1, thereby fixing the support shaft 12. A detailed explanation will be given below with reference to each figure.

In the first embodiment shown in FIG. 1, the diameter of the shaft portion 13 is made to be approximately the same as the inner diameter of the hole 11, and the inner diameter of the ring member 14 is slightly smaller (or slightly sloped) than the diameter of the shaft portion 13. It is shaped like a wedge. Therefore, the shaft part 13 formed at the lower part of the support shaft 12 is made to protrude from the inside of the half 1 through the hole 11, and the ring member 14 is press-fitted into the protruding part until it comes into contact with the housing. This makes it possible to secure the support shaft 12 to the half 1 sufficiently firmly without easily falling off. As shown in the figure, if tapered surfaces 11a and 14a having the same slope are formed at the lower part of the hole 11 and the upper part of the ring member 14, respectively, the two will be more firmly connected.

Next, second and third embodiments of the reel support shaft fixing mechanism of the present invention will be described with reference to FIGS. 2 and 3. First, the above-mentioned first
The difference from the embodiment is that a cap-shaped member 15 is used as the ring member 14. This can suppress expansion of the ring member 15 due to press fitting compared to a general ring member without a lid, so that the bonding force after fixing becomes stronger. On the other hand, the difference between the third embodiment shown in FIG. 3 and the first embodiment is that an uneven portion 13a is provided on the side surface of the shaft portion 13. By making the uneven portion 13a bite into the inside of the ring member 14, the bonding force between the two is further strengthened. Note that a protrusion, a concave shape, or a convex portion may be formed instead of the concavo-convex portion 13a.

Further, the tapered surface 14a of the ring member 14 is also provided with an uneven portion as shown in FIG. may be formed. With this configuration, the tapered surface 1 on the hole 11 side of the half 1
The frictional force against 1a increases, further strengthening the bonding force between the two.

5A to 5C are plan views showing the shapes of the shaft portion 13 and the ring member 14 (or 15).
That is, although the cross-sectional shape is generally round as shown in Figure A, it may be square or triangular as shown in Figures B and C.

In the above explanation, an example was explained in which the reel support shaft fixing mechanism of the present invention is applied to a support shaft that supports the reel of a VHS-C video tape cassette, but the reel support shaft fixing mechanism of the present invention is not limited to this, and can be applied to any type Of course, it may also be applied to fixing the support shaft.

〔effect〕

Since the reel support shaft fixing mechanism of the present invention is configured as described above, the support shaft can be securely attached and fixed to the half (casing), and there is no fear that the support shaft will expand during installation. Therefore, the expansion of the support shaft hinders the smooth rotation of the reel,
Furthermore, the problem of the conventional example, which causes a serious hindrance to tape running, can be reliably resolved.
Furthermore, the technology disclosed in, for example, Japanese Utility Model Application Publication No. 59-42581 is a method for manufacturing a caulking ring (ring member 1 of the present invention).
4) into the thin shaft portion (corresponding to the shaft portion 13), the lower end surface of the thin shaft is press-deformed and caulked, which is a troublesome work. The operation is simple because it is press-fitted at the same time. Furthermore, after press-fitting, the frictional force increases due to the shape of the concave and convex portions formed in the contact area of the casing, so it does not loosen easily and the bond between the two becomes even stronger, which is an excellent practical effect. It is something.

[Brief explanation of the drawing]

1 to 3 are partially sectional side views of the first to third embodiments of the reel support shaft fixing mechanism of the present invention, and FIGS. 4A to 4C are tapered surface shapes of the ring member used in the present invention. 5A to 5C are plan views showing each embodiment of the shaft portion and the ring member, and FIGS. 6 and 7 show a conventional example of the reel support shaft fixing mechanism. FIG. 3 is a longitudinal cross-sectional view showing the vicinity of the reel support shaft of the cassette together with other constituent parts. 1...Casing (cassette half), 11...hole,
11a, 14a...Tapered surface, 12...Support shaft, 13...Shaft portion, 14...Ring member,
15... Cap-shaped ring member.

Claims (1)

[Scope of utility model registration request] In a reel support shaft fixing mechanism in which a hole is bored in a predetermined location of a housing and a support shaft of a reel is fixed in the hole, a shaft portion is formed at a lower part of the support shaft to protrude outside the housing from the hole, The shaft part is formed from the outside of the casing into a wedge shape with an inner diameter slightly smaller than the diameter of the shaft part or slightly inclined, and a part that contacts the casing to increase the frictional force when coupled. A reel support shaft fixing mechanism, characterized in that the support shaft is fixed by press-fitting a ring member provided with a smoothing shape to a position where it contacts the housing.