JPH0463477B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape cassette used, for example, in a VTR (video tape recorder, video tape player), and a method for assembling the tape cassette.

More specifically, the tape wound around the reel hub can be seen through from the outside of the cassette, and the reel hub around which the tape is wound is a tape cassette with anti-wear measures. has prepared an upper reel flange made of transparent synthetic resin and a reel hub made of synthetic resin with high wear resistance and low coefficient of friction, and despite these limited materials, these upper reel flange and reel hub The present invention relates to a tape cassette that is robust, inexpensive, and has a simple assembly process, and a method for assembling the same.

First, in order to facilitate understanding, a tape cassette for a VTR to which the present invention can be applied will be explained using FIGS. 1 to 3.

In FIGS. 1 and 2, 1 indicates the entire tape cassette with a rectangular planar outline, and 2 indicates its casing, which includes an upper half 3 and a lower half made of synthetic resin, such as ABS resin. 4, and in the longitudinal direction inside thereof is a feed reel 20, which will be described later.
and a take-up reel 21 are arranged in parallel. Reference numeral 5 denotes an opening/closing lid body made of a similar resin molded product which is pivotally attached to the front side of the case 2, and this lid body 5 has left and right side plates 7a and 7b with symmetrical pivots 6a and 6b projecting inward. However, it is elastically biased in the closing direction (arrow a indicates the opening direction) as shown in the figure. 8 (8a, 8b) are guide grooves extending from both sides of the upper half 3 to both sides of the lid body 5, with the dividing line between the upper half 3 and the lower half 4 as the border, on the left and right sides of the case body 2; It shows a guide groove formed at a position near the rear of the bottom of the lower half 4,
These guide grooves 8 and 9 are guide means when the cassette 1 is mounted on the cassette holder on the VTR main body side, and are used for both X-direction insertion and Y-direction insertion, respectively. Further, in order to see through the tape winding layer of the feeding reel 20, the cassette 1 of this example is provided with a circular bright portion 10 on the right side of the upper surface of the upper half 3, and a rectangular contour on the adjacent left side. A shallow recess 11 is formed in which a name plate 12 (labels) is attached. 13 is a mask at the center of the transparent part.

On the other hand, the feed reel 20 and the take-up reel 21 each have a hub 2 having hub holes 24, 24a, and 24b.
3 (23a, 23b), upper flange 22 (22a,
22b) and square teeth 2 with a constant pitch around the circumference.
A lower flange 2 in the form of a ratchet wheel with 6
5 (25a, 25b), the tape T is guided from the feed reel 20 to the inside of the front plate of the lid body 5 by guide pins 27a and 28a,
It reaches the take-up reel 21 through guide pins 27b and 28b. Reference numerals 33 (33a, 33b) are bell crank-shaped ratchet pieces that engage with the square teeth 26 of the lower flange 25 of each reel. When the lid body 5 is closed, one end (locking end) of each ratchet piece 33 engages with the tooth groove of the square tooth 26, and the tapes of both reels are interlocked via the respective pivot shafts 6. Rotation in the feeding direction (feeding reel: clockwise, take-up reel: counterclockwise) is prevented. Note that each ratchet piece 33 is biased toward the square tooth 26 via a coiled spring. Further, 30 is a partition plate, 31 is a protection plate for the tape T when the lid 5 is closed and the cassette is not in use, and 32 is a tape slack prevention member. 34 is a lock lever for locking the lid, and pin 35
When the lid is closed, the claw piece 36 of the lock lever engages with the locking square hole 13 of the lid body 5 to lock the lid body, and the cassette 1 is attached to the holder on the VTR side from the X direction or the Y direction. When the lock lever 34 is locked, the release rod on the holder side enters the notch 14 and presses the pressing portion 37 at the free end of the lock lever 34, thereby releasing the lock lever 34. Reference numeral 38 denotes a reel holding means, for example, a substantially cross-shaped plate spring, which is used as a reel holding device, and its arm ends hold down a steel ball 39 fitted into the center of each upper flange 22a, 22b.

The reels 20 and 21 described above are usually made by combining an upper reel member 40A having an upper flange 22 and a lower reel member 40B integrally having a lower flange 25 and a hub 23, respectively, as shown in FIG. Molded with resin, and after molding, the upper reel member 40
The reference surface 22' of A and the reference surface 23' of the upper end of the hub of the lower reel member 40B are joined together.
Conventionally, such reel components have been assembled by applying an adhesive to the surfaces to be joined, that is, in this case, the surface which also serves as a reference surface.

However, in this case, since the abutting surfaces themselves serve as reference surfaces during joining, there is a drawback that it is difficult to maintain parallelism between the upper and lower flanges of the reel when an adhesive is interposed on this surface. Since poor parallelism between the upper and lower flanges causes jitter, etc., this parallelism must be strictly controlled. In addition, if the upper reel member 40A and the lower reel member 40B are made of different materials, that is, polyacetal resin is used for the lower reel member, which requires wear resistance and a small coefficient of friction, and polyacetal resin is used for the upper reel member, which requires transparency. When using acrylic and styrene resins, it is difficult to select an adhesive that is compatible with both materials.

In view of the above-mentioned points, the present invention makes it possible to create a reel with high precision using upper and lower reel members made of different materials, allows the state of tape winding to be seen through, and allows for reel driving, tape running, and cassette attachment/detachment. It is an object of the present invention to provide a tape cassette with improved characteristics, and a method of assembling the tape cassette so that the same can be easily assembled.

The tape cassette of the present invention includes a cassette cassette body having a transparent window in a part of the upper half, a reel hub integrally molded with the lower reel flange from a synthetic resin with a low coefficient of friction and high wear resistance, and a transparent synthetic resin. It consists of an upper reel flange molded with resin, a plurality of protrusions are provided on the upper end surface of the reel hub, and a plurality of engagement holes are provided on the upper reel flange, and after the protrusions are passed through the engagement holes, The reel hub and the upper reel flange were integrated by heat melting, and the integrated reel was housed in a cassette case with the upper reel flange facing the transparent window of the upper half, and wound around the lower reel flange. This is characterized in that the magnetic tape can be seen through from outside the upper half.

Further, the method for assembling the tape cassette according to the present invention includes a cassette cassette body having a transparent window in a part of the upper half, and a reel hub integrally molded with a lower reel flange made of synthetic resin having a low coefficient of friction and high wear resistance. and an upper reel flange molded with transparent synthetic resin, and inserting a plurality of protrusions provided on the upper end surface of the reel hub into a plurality of engagement holes provided in the upper reel flange;
The process of integrating the upper reel flange with the protrusion inserted into the reel hub by heat melting, and storing the integrated reel in the cassette case so that the upper reel flange faces the transparent window of the upper half. It is characterized by having a process.

An example of the present invention will be described below with reference to FIGS. 4 and 5. Note that this figure only shows the reel, and the other configurations are the same as those in FIGS. 1 and 2, so detailed explanation thereof will be omitted.

In FIGS. 4 and 5, 41 is an upper reel member having an upper flange 43, and 42 is a lower flange 4.
4 and a hub 45, each of which is formed by molding a desired synthetic resin. The lower reel member 42 has a hub hole 46 in which a reel holder on the apparatus main body side is fitted into the hub 45, and a leaf spring serving as a reel holding means attached to the upper surface of the cassette case is provided at the upper end of the hub. It has a spherical top 47 that is pressed directly at the end. In addition, various means can be considered as means for pressing the reel using a leaf spring, such as pressing a steel ball fitted into the center of the upper flange as shown in FIG. 2, and this example shows one such means. It's just a matter of time.

An example of the present invention includes a hub 4 as shown in FIG. 5A.
A reference surface 48 parallel to the annular lower flange 44 is formed on the upper end surface of the reference surface 48 with the apex 47 as the center, and, for example, projecting pieces 49 for a plurality of pieces are provided integrally with the reference surface 48. . Further, in the upper reel member 41 as well, a reference surface 50 parallel to the upper flange 43 is similarly formed at a portion facing the reference surface 48 on the lower reel member 42 side, and protrusions are formed at positions corresponding to the protrusions 49. A plurality of engagement holes 51 through which the pieces can be inserted are formed. In this case, the top 47 at the center of the hub and the top surface of the upper flange 43 are made substantially on the same plane, and the melted and expanded portion of the protrusion 49 (described later) is positioned below the top 47 and the top surface of the top flange 43 so that the hub side The reference surface 48 of the upper reel member is formed as a concave groove, and the reference surface 50 of the upper reel member is formed as a convex surface that fits into this concave groove. and,
A transparent window is formed in a part of the top plate of the cassette case that houses the reel, and the upper flange 43 of the reel is made of a highly transparent material so that the tape wound around the reel can be seen through the window. . Possible materials suitable for this purpose include acrylic styrene resin or polycarbonate resin. On the other hand, as the material forming the hub 45, the hub top 47
A resin material that is wear-resistant and has a small coefficient of friction is used because it is necessary to make contact with the leaf spring, which is the pressing means on the case side, and to improve slippage when fitting the reel holder into the hub hole 46. use. Materials that meet this purpose include polyacetal resin,
Alternatively, a mixed resin of polycarbonate resin and fluororesin can be considered. In this configuration, since the reference surface 48 on the hub side serves as a reference for determining the facing distance D between the upper and lower flanges, the upper reel member 41
The hub 45 is overlapped with the upper end surface of the hub 45.
The upper flange 4 corresponding to the upper surface of the edge 45a of
It is permissible to form a small distance d between the base plate and the lower surface of the base plate.

Then, the upper reel member 41 and the lower reel member 42
First, as shown in FIG. 5A, the upper reel member 41 is brought into contact with its reference surfaces 50 and 48 against the upper end surface of the hub of the lower reel member 42, and each protrusion 49 is engaged with the corresponding one. It is placed so as to be inserted into the hole 51 (the chain line shows the state before the upper reel member 41 is placed). Thereafter, as shown in FIG. 5B, the tip 49a of the protruding piece 49 facing the engagement hole 51 is heated and melted, that is, melted and expanded to be welded to the upper reel member 41.
When the upper reel member 41 and the lower reel member 42 are integrated, the reference surfaces 50 and 4 of both members 41 and 42
Since there is no need to interpose an adhesive to the reference surface 50 formed on both members 41 and 42,
and 48 are maintained accurately so that the reference surfaces 50 and 48 can be used to assemble reels of accurate dimensions. In particular, the parallelism between the upper and lower flanges 43 and 44 can be achieved extremely accurately. Furthermore, even when the reel members 41 and 42 are connected to each other, it is only necessary to melt the protruding piece 49 formed on the member 42 on one side, so there are no restrictions in selecting a resin material suitable for the function of each reel member 41 and 42. You can create a good reel without suffering any damage. Next, the tape T is wound around the reel, and the reel flange 4 is then wrapped around the reel.
The desired tape cassette is assembled by storing it in the cassette case 2 shown in FIGS. 1 and 2 so that the tape cassette 3 faces the transparent window of the upper half 3.

According to the present invention, both the upper and lower reel members 41 and 4
2 is a resin material suitable for each function, that is, a resin material with good transparency and a resin material with high abrasion resistance and a small coefficient of wear, but it is easy to create a reel with good parallelism of both upper and lower flanges 43 and 44. can be made. And the upper flange 4 of the reel
Since the tape 3 is made of a highly transparent resin material, the state in which the tape is wound can be seen from outside the cassette. In addition, since the reel hub 45 and the lower reel flange 44, which are integral with each other, are made of a resin material with a small coefficient of friction and high wear resistance, attachment to and detachment from the reel holder can be performed extremely smoothly, and the lower reel flange 44 and the magnetic tape to be wound, and between the lower reel flange 44 and the cassette case 2, the contact friction is small and wear is less likely to occur, so that the reel rotational drive and tape running can be improved.

When assembling the reel, the upper reel member 41 is placed on the upper end surface of the hub of the lower reel member 42 by inserting each projection 49 into the corresponding engagement hole 51, so that the upper flange 43 and the hub 45 are Positioning is performed, and the bonding position between the two can be made constant. Even if the upper flange 43 and the hub 45 are subjected to high-frequency vibrations during subsequent welding, the upper flange 43 and the hub 45 will not rotate and become misaligned.Furthermore, even if the upper flange 43 and the hub 45 are subjected to external pressure after assembling the reel, the upper flange 43 relative to the hub 45 will not rotate. Since the relative rotation of the reel and tape cassette can be prevented, the reliability of the reel and the tape cassette can be improved.

Further, since the tip of the protruding piece 49 is located lower than the top 47 at the center of the hub and the upper surface of the upper flange 43, the reel is housed in the cassette case, and the top 47 at the center of the hub is held down by the reel holding means. Even when the reel is pressed, there is no risk that the tip will come into contact with the reel holding means, so good rotation of the reel can be achieved at the same time.

In the above example, the case where the present invention was applied to a tape cassette for a VTR was described, but it can also be applied to other tape cassettes.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a tape cassette for a VTR according to the present invention, FIG. 2 is a cross-sectional view thereof,
Figure 3 is a sectional view showing the assembled state of a conventional reel;
FIG. 4 is a sectional view showing an example of the reel according to the present invention, and FIGS. 5A and 5B are sectional views of the main parts, respectively, showing an assembled state. 41 is an upper reel member, 42 is a lower reel member, 4
3 is an upper flange, 44 is a lower flange, 45 is a hub, 48 and 50 are reference surfaces, 49 is a projecting piece, and 51 is an engagement hole.

Claims (1)

[Scope of Claims] 1. A cassette cassette body having a transparent window in a part of the upper half, a reel hub integrally molded with the lower reel flange from a synthetic resin with a low coefficient of friction and high wear resistance, and a transparent synthetic resin. The reel hub has a plurality of protrusions on the upper end surface, the upper reel flange has a plurality of engagement holes, and the protrusions pass through the engagement holes. These are integrated by heat melting, and the integrated reel is housed in the cassette case so that the upper reel flange faces the transparent window of the upper half, and is wound around the lower reel flange. A tape cassette characterized in that the magnetic tape can be seen from outside the upper half. 2. A cassette case with a transparent window in a part of the upper half, a reel hub integrally molded with the lower reel flange from a synthetic resin with a low coefficient of friction and high wear resistance, and a top half molded with a transparent synthetic resin. a reel flange, and inserting a plurality of projections provided on the upper end surface of the reel hub into a plurality of engagement holes provided in the upper reel flange; and an upper reel flange into which the projections are inserted. assembly of a tape cassette, which comprises the steps of: integrating the reel hub and reel hub by heat melting; and storing the integrated reel in the cassette case so that the reel flange faces the transparent window of the upper half. Method.