JPS6349903Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is a tape cassette that is most suitable for application to, for example, a tape cassette for a video tape recorder.

BACKGROUND TECHNOLOGY AND PROBLEMS Conventionally, tape cassettes for video tape recorders include a cassette housing composed of an upper half and a lower half, a pair of reels rotatably housed within the cassette housing, and both reels. The tape is wound and stored on a reel, and the approximately central portion in the longitudinal direction is fixed to the inner surface of the upper half, and the central portions of the reels are elastically attached to the lower half at both ends in the longitudinal direction. There is a tape cassette consisting of a leaf spring that is designed to press against the tape.

By the way, when this type of tape cassette is installed in a video tape recorder, both of the reels are pushed up by the reel stand against the spring force of the leaf spring and are lifted off the inner surface of the lower half. In each case, a fairly strong pressing force is applied to both ends of the leaf spring. On the other hand, both ends of the leaf spring must properly press the center portions of both reels in the axial direction. Therefore, the substantially central portion of the leaf spring must be firmly fixed to the upper half to prevent the leaf spring from being accidentally twisted or falling off from the upper half due to the above-mentioned pressing force. In particular, since the cassette case is small and both reels are placed extremely close to each other, a leaf spring is fixed to the upper half between the two reels, near the straight line connecting the centers of the reels. In cases where it is difficult to secure sufficient space for the flat spring, the flat spring is bent into a V-shape, and the leaf spring is fixed to the upper half at the bending point. A letter-shaped leaf spring is easily twisted, and the leaf spring must be more firmly fixed to the upper half.

Conventionally, however, two dowels are integrally molded into the upper half of the leaf spring and are spaced apart from each other in the width direction perpendicular to the longitudinal direction of the leaf spring. In many cases, the lower ends of two dowels are welded to each other, and the leaf spring is fixed to the upper half at two points. However, in such a structure using two dowels, the dowel welding operation must be performed twice, resulting in a large number of assembly steps and a problem in productivity. In addition, two small holes must be provided approximately in the center of the leaf spring to be inserted into the two dowels.
In particular, when applied to a V-shaped leaf spring where the central part cannot be sufficiently wide, the two small holes are placed close to each other, resulting in the strength of the central part of the leaf spring. is extremely low, and the leaf spring is easily broken in the center, making it extremely unreliable. However, with a structure in which the leaf spring is fixed to the upper half using one dowel at one point, the attachment strength of the leaf spring to the upper half is insufficient, and the leaf spring is easily twisted or fallen off unexpectedly. I have the problem you mentioned.

In addition, conventionally, a dowel was used as a reference for positioning the approximately central part of the leaf spring, but if the dowel is melted too much, the approximately central part of the leaf spring tends to be misaligned with respect to the upper half when the dowel is welded. It was. and,
If the approximate center of the leaf spring is misaligned, the balance between the pressing force on the pair of reels by both ends of the leaf spring will be disrupted, making it impossible to rotate the pair of reels stably in a well-balanced manner, resulting in unstable tape running. There was a problem.

Purpose of the invention The present invention aims to provide a tape cassette that can solve the above-mentioned problems.

Summary of the invention The present invention provides a hole at approximately the center in the longitudinal direction of the leaf spring, and a positioning notch at one side of the approximately center, which is integrally formed on the lower surface of the upper half. Insert the dowel into the hole and engage the notch with a guide post longer than the dove provided on the lower surface of the upper half to position approximately the center of the leaf spring in the upper half. By welding the lower ends of the dowels, the approximately central portion of the leaf spring is fixed to the upper half, and a pair of upper and lower clamping surfaces are provided approximately at the central portion of the leaf spring and at the periphery of the dowel between the two halves. The plate spring is clamped and fixed from above and below with the upper half, and can be fixed very easily and firmly with the approximately central part of the leaf spring positioned extremely accurately on the upper half.

Embodiment An embodiment in which the present invention is applied to a small tape cassette for a video tape recorder will be described below with reference to the drawings.

First, FIGS. 1 and 2 show the entire tape cassette, and the cassette housing 1 is composed of an upper half 2 and a lower half 3, both of which are integrally molded from synthetic resin. Upper half 2 and lower half 3
are fitted from above and below, and are screwed together at five points, for example, at the four corners and approximately at the center, using set screws 4a to 4e. A pair of left and right reels 5 and 6 are rotatably housed in the cassette housing 1, and the magnetic tape 7 is attached to these reels 5, 6.
6 and are respectively wrapped and stored. A rotatable front cover 9 is attached to the front opening 8 of the cassette housing 1, and the magnetic tape 7 is guided by a pair of tape guides 10 and 11 to the front opening 8 along the inside of the front cover 9. It was passed while crossing 8.

A leaf spring 13 is housed in the space between the lower surface of the upper half 2 and the upper surfaces of both reels 5 and 6 within the cassette housing 1. This leaf spring 13 has a planar shape bent into a substantially V-shape, and is fixed to the upper half 2 at a bending point, which is a substantially central portion 13a in the longitudinal direction, as will be described later. Both ends 13b and 13c in the longitudinal direction of this leaf spring 13
is elastically pressed onto small protrusions 5a, 6a integrally formed on the center portions of the upper surfaces of both reels 5, 6, thereby pressing both reels 5, 6 toward the lower half 3 side. Note that the leaf spring 13 is made of a metal spring such as a stainless steel plate or a phosphor bronze plate.

By the way, the bottom surface 1 of the almost central part of the cassette housing 1
A is provided with a light emitting element insertion hole 14 as shown in FIG. There is. When this tape cassette is attached to a video tape recorder, the third
As shown in the figure, a light emitting element 16 such as a small lamp is inserted into the light emitting element insertion hole 14, and a pair of light receiving elements (not shown) are positioned facing each other outside both light detection windows 15. When the tape end is reached during recording or reproduction of the magnetic tape 7 by a video tape recorder, the light emitted from the light emitting element 16 passes through the transparent leader tape and passes through the light detection window 15 on either side. The light is received by the light receiving element and the end of the tape is detected. Note that the running of the magnetic tape 7 is automatically stopped based on this tape end detection, and this tape cassette has a structure compatible with a tape end detection device of a video tape recorder.

As shown in FIGS. 3 to 5, the inside of the light emitting element insertion hole 14 is closed with a closing body 17 to prevent dust from accidentally entering the cassette housing 1 from the light emitting element insertion hole 14. ing. This obstruction 1
7 is made of, for example, a transparent synthetic resin, and has a substantially U-shaped cross section. This closing body 17 is vertically installed and installed between the upper and lower halves 2 and 3 around the light emitting element insertion hole 14.

That is, the inner surfaces 2a and 3a of the upper and lower halves 2 and 3 are provided with partition walls [cassette housing 1
Walls 18 and 19 that partition the interior between the reels 5 and 6 and the front opening 8 are integrally formed, and a pair of left and right ribs 20 and 21 are provided on the rear sides of these partition walls 18 and 19. They are integrally molded and provided vertically so that they are butted against each other from above and below. Further, on the inner surfaces 2a and 3a of the upper and lower halves 2 and 3, there are screws 4e for screwing approximately the center of the cassette housing 1.
Cylindrical bosses 22 and 23 for fixing with screws are integrally molded so as to butt against each other from above and below. They are arranged at intervals behind the partition wall 18.

The U-shaped closure body 17 as described above is
It stands vertically around the light emitting element insertion hole 14 and is assembled between the upper and lower halves 2 and 3, and in this case, the closing body 17 is attached to the pair of left and right front edges 17 forming the U-shape.
a into the inside of the pair of left and right ribs 20, 21, and the partition walls 18, 19 and the bosses 22, 2
3 and positioned at 3 points.
The set screw 4e is a self-tapping screw, which is screwed into a self-tapping hole 25 provided in the boss 22 from an insertion hole 24 provided at the top of the boss 23, and is inserted into the closure body. Since the upper and lower halves 2 and 3 are fixed by pulling each other at a position near the upper and lower halves 17, the closing body 17 is firmly fixed between the upper and lower halves 2 and 3.

Next, a structure for fixing the substantially central portion 13a of the leaf spring 13 will be explained with reference to FIGS. 3 to 5.

First, one dowel 27 is integrally formed on the inner surface 2a of the upper half 2 at a position directly above the light emitting element insertion hole 14. On the other hand, approximately the center part 1 of the leaf spring 13
3a has one small hole 2 inserted into the dowel 27.
8 is provided.

First, the substantially central portion 13a of the leaf spring 13 is
It is inserted into the dowel 27 through the small hole 28, and the dowel 27
By welding the lower end 27a of the upper half 2
is fixed at one point. At this time, as shown in FIG. 4, the front edge 30 of the approximately central portion 13a of the leaf spring 13 is brought into contact with the rear end surface 20a of both ribs 20 of the upper half 2, and the rear end of the approximately central portion 13a A semicircular notch 32 provided on the end edge 31 is engaged with the outer periphery of the boss 22, which is a guide post longer than the dowel 28 integrally molded on the lower surface of the upper half 2, so that the leaf spring 13 The parallelism with respect to the straight line connecting the centers of both the reels 5 and 6 is determined.

Next, after fixing the leaf spring 13 to the upper and lower halves 2 and 3 at one point as described above, the upper half 2 is fitted onto the lower half 3, and the five set screws 4 are inserted as described above.
When the upper and lower halves 2 and 3 are screwed together at points a to 4e, as shown in FIG. The leaf spring 13 is clamped from above and below by a pair of upper and lower clamping surfaces, and the approximately central portion 13a of the leaf spring 13 is extremely firmly fixed.

That is, the clamping surface 33 on the upper half 2 side is made up of the inner surface 2a itself, and the clamping surface 33 on the lower half 3 side is made up of the inner surface 2a itself.
4 is constituted by the upper end surface of the closure body 17, and the substantially central part 13a of the leaf spring 13 and the peripheral part of the dowel 27 are clamped from above and below by a pair of upper and lower clamping surfaces 33 and 34. It is fixed extremely firmly. Therefore, although the substantially central portion 13a of the leaf spring 13 is fixed to the upper half 2 at one point with one dowel 27, the upper and lower halves 2 and 3 are fixed with set screws 4a to 4e. At the time of completion, the substantially central portion 13a of the leaf spring 13 is connected to the upper and lower halves 2,
It is very firmly fixed between 3. As a result, the leaf spring 13 has a substantially V-shape as described above, and due to the pushing repulsion of the reels 5 and 6 by the opposite ends 13b and 13c, a prying force is applied to the substantially central portion 13a of the leaf spring 13. Although this is likely to occur, it is strongly prevented from twisting and falling off from the dowel 27.

In the embodiments described above, the closure body 17 is molded separately from the upper and lower halves 2 and 3 and is incorporated between the upper and lower halves 2 and 3. However, the closure body 17 may be integrally molded with the lower half 3. If provided as such, the lower clamping surface 34 will be provided on the lower half 3 itself.

Application Examples The present invention is not limited to tape cassettes for video tape recorders, but can be applied to tape cassettes for various other recording/reproducing devices and information processing devices.

Effects of the Invention As mentioned above, the present invention allows the approximately central portion of the leaf spring to be extremely easily fixed to the upper half by welding one dowel, and the approximately central portion of the leaf spring to be sandwiched between the upper and lower halves from above and below. Because it can be fixed extremely firmly, it is possible to reliably prevent the leaf spring from twisting, rattling, or falling off inside the cassette housing, and there is no reduction in the strength of the leaf spring itself. There is no inconvenience such as the central part of the leaf spring breaking unexpectedly, and reliability is significantly improved.

Moreover, when fixing the approximately central portion of the leaf spring to the upper half, the positioning notch provided on one side of the approximately central portion of the leaf spring is engaged with the guide post provided on the upper half for positioning. Approximately the center of the leaf spring can be positioned and fixed to the upper half very precisely. Therefore, the pair of reels can be pressed accurately in a well-balanced manner at both ends of the leaf spring, and the pair of reels can be stably rotated in a well-balanced manner, thereby stabilizing the running of the tape. Moreover, a positioning structure in which a notch provided on one side of the approximately central portion of the leaf spring is laterally engaged with the guide post is, for example, a positioning hole provided approximately in the central portion of the leaf spring that is provided in the upper half. Assembling the leaf spring is easier than a structure in which the leaf spring is inserted into a positioning pin.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a small tape cassette for a video tape recorder, in which FIG. 1 is an overall plan view, FIG. 2 is a side view thereof, and FIG. FIG. 4 is an enlarged sectional view taken along the - line arrow in the figure, FIG. 4 is a sectional view taken along the - line arrow of FIG. 3, and FIG. 5 is an exploded perspective view of the main parts. In addition, in the symbols used in the drawings, 1...Cassette housing, 2...Upper half, 3...Lower half,
4a, 4b, 4c, 4d, 4e...stop screws, 5,
6... Reel, 7... Magnetic tape, 13a... Leaf spring, 13a... Substantially central portion of leaf spring, 13b,
13c...Both ends of the leaf spring, 22...Boss serving as a guide post, 27...Dowel, 27a...Lower end of dowel, 28...Small hole, 32...Positioning notch,
33, 34... are the clamping surfaces.

Claims (1)

[Scope of utility model registration request] A cassette housing consisting of an upper half and a lower half, a pair of reels rotatably housed within the cassette housing, a tape wound and housed around both reels, and a tape approximately at the center in the longitudinal direction. A tape cassette comprising: a leaf spring fixed to the inner surface of the upper half, and a leaf spring configured to elastically press the center portions of the reels toward the lower half at both ends in the longitudinal direction; A hole is provided at approximately the center in the longitudinal direction of the leaf spring, and a positioning notch is provided at one side of the approximately center portion, and a dowel integrally formed on the lower surface of the upper half is inserted into the hole; engaging the notch with a guide post longer than the dowel provided on the lower surface of the upper half to position approximately the center of the leaf spring on the upper half;
In this state, by welding the lower end of the dowel, the approximately central part of the leaf spring is fixed to the upper half,
A tape cassette, characterized in that a peripheral portion of the dowel at a substantially central portion of the leaf spring is clamped from above and below by a pair of upper and lower clamping surfaces provided between the two halves.