JPH02146166A - Tape cassette and its assembling method - Google Patents

Abstract

PURPOSE:To observe through a tape wound condition by providing a transparent window at an upper half, and housing a reel hub integrally molded with a lower reel flange, and a reel obtained with integrating an upper reel flange consisting of a transparent synthetic resin by means of thermal melting. CONSTITUTION:The reel, whose upper reel flange 43 is formed of the transparent synthetic resin, is housed in a cassette enclosure 2 having a transparent window 10 at one part of an upper half 3. The reel consists of a reel hub 45, which is composed of the synthetic resin having a small frictional coefficient and large wear resistance and integrally molded with a lower reel flange 44, and the upper reel flange 43, which is composed of the transparent synthetic resin and molded, and plural projecting pieces 49 provided on the upper edge surface of the reel hub 45 are penetrated through plural engaging holes 51 provided at the upper reel flange 43, then the reel hub 45 and the upper reel flange 43 are integrated by the thermal melting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape cassette used in, for example, 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. prepares an upper reel flange made of transparent synthetic resin and a reel hub made of synthetic resin with high wear resistance and a small number of friction parts,
The present invention relates to a tape cassette in which the upper reel flange and the reel hub are integrated in a sturdy, inexpensive, and simple assembly process despite these limited materials, and a method for assembling the tape cassette.

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) shows the whole tape cassette with a rectangular planar outline, and (2) shows its casing, which is the upper half of a synthetic resin molded product such as ABS resin. (3) and a lower half (4), and a pay-out reel (20) and a take-up reel (21), which will be described later, are arranged in parallel in the longitudinal direction inside the half. (5) is an opening/closing lid body made of a similar resin molded product pivotally attached to the front side of the case body (2), and this lid body (5) projects inwardly with symmetrical pivots (6a) and (6b). It has left and right side plates (7a) and (7b) to be installed,
It is elastically biased in the closing direction (arrow a indicates the opening direction) as shown in the figure. (8) (8a, 8b) are the left and right sides of the case (2), and the lid body (
5) shows a guide groove extending to both sides, and (9) shows a guide groove formed near the rear of the bottom of the lower half (4), and these guide grooves (8) and (9) are on the VTR body side. This is a guide means when mounting the cassette (1) on the cassette holder, and is used for both X-direction insertion and Y-direction insertion, respectively. In addition, 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 transparent part (10) on the right side of the upper surface of the upper half (3), and the adjacent transparent part (10) For example, a shallow recess (11) with a rectangular outline is formed on the left side, and a name plate (12) is placed in this.
(labels) are 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 (23) (23a) having a hub hole (24) (24a, 24b).

23b), upper flange (22) (22a, 22b)
) and a ratchet wheel-shaped lower flange (25) having, for example, square teeth (26) at a constant pitch around the circumference (25
a, 25b), and tape ('r
) is guided from the feed reel (20) to the inside of the front plate of the lid (5) by guide pins (27a) and (288),
It reaches the take-up reel (21) through the guide pins (27b) and (28b). (33) (33a, 33b) are bell crank-shaped ratchet pieces that engage with the square teeth (26) of the lower flange (25) of each reel, and these ratchet pieces (33) are pivoted by the pin (33'). The ratchet pieces (33) are connected to each other at one end (locking end) when the lid (5) is closed. are engaged with the tooth grooves of the square teeth (26) to prevent rotation of both reels in the tape feeding direction (two clockwise directions for the feeding reel and two counterclockwise directions for the take-up reel). In addition, each ratchet piece (3
3) are each 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 cassette is not in use with the lid (5) closed, and (32) is a tape slack prevention member. (3
4) is a lock lever for locking the lid body, which is pivoted with a pin (35) and locks into the lock hole (I3) of the lid body (5) when the lid is closed.
When the claw piece (36) of the lock lever engages to lock the lid, and the cassette (1) is attached to the holder on the VTR side from the ) and presses a pressing portion (37) at the free end of the lock lever (34) to release the lock lever (34). (38) is a reel holding means which is used as a reel holding and is made of, for example, a substantially cross-shaped plate spring, and each upper flange (22a),
A steel ball (22b) fitted into the center of
39).

As shown in FIG. 3, the reels (20) and (21) described above usually include an upward reel member (40A) having an upper flange (22), a lower flange (25) and a hub (23).
) and the lower reel member (40B) integrally formed with the upper reel member (40A) are molded with synthetic resin, and after molding, the upper reel member (40A
) and a reference surface (23') at 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. Father reel member (40A) and lower reel member (4
0B) are made of different materials, i.e., polyacecool resin is used for the lower reel member, which requires wear resistance and a small coefficient of friction, and acrylic/styrene resin is used for the upper reel member, which requires transparency. It has been difficult to select an adhesive that is compatible with both materials.

As far as the above points are concerned, 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,
To provide a tape cassette with improved tape running, cassette attachment/detachment, etc., and a tape cassette assembly method that allows easy assembly.

The tape cassette of the present invention includes a cassette case 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 small coefficient of friction (high wear resistance), and a transparent window. It consists of an upper reel flange molded with synthetic resin, and the upper end surface of the reel hub has a plurality of protrusions, and the upper reel flange has a plurality of engagement holes, and after passing the protrusions through the engagement holes. , these one reel hub and upper reel flange are integrated by heat melting, and this integrated reel is housed in a cassette case so that the upper reel flange faces the transparent window of the upper half,
It is characterized in that the magnetic tape wound around the lower reel flange can be seen through from outside the upper half.

In addition, the method for assembling the tape cassette according to the present invention includes a cassette case having a transparent window in a part of the upper half, and a synthetic resin having a small coefficient of friction (high wear resistance) that is integrally molded with the lower reel flange. a step of preparing a reel hub 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 and the reel hub into which the protrusion has been inserted is carried out 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. The invention is characterized by comprising the steps of:

The present invention will be described in detail 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 Figures 4 and 5, (41) is the upper flange (4
(42) has 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) into which a reel holder on the apparatus main body is fitted into its hub (45), and a reel holding means attached to the upper surface of the cassette case at the upper end of the hub. It has a spherical top (47) that is pressed directly by the free end of the leaf spring. 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 is to form a reference plane (48) on the upper end surface of the hub (45) that is parallel to the annular lower flange (44) with the apex (47) as the center, as shown in FIG. 5A. For example, a plurality of protrusions (49) are provided integrally with the reference surface (48) so as to protrude from above the reference surface (48). Also, the upper reel member (41)
Also, the reference surface (48) on the lower reel member (42) side
) is similarly formed with a reference surface (50) parallel to the upper flange (43), and the protruding piece (49)
), the engagement holes (51
) to multiple addresses. In this case, the center top of the hub (4
7) and the upper surface of the upper flange (43) are made substantially on the same plane, and the melted and expanded portion of the protrusion (49), which will be described later, is placed on the top (4).
7) and the reference surface (48) on the hub side is formed into a groove in order to be positioned below the upper surface of the upper flange (43), and the reference surface (50) of the upper reel member is fitted into this groove. It is formed into a convex surface. 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 window so that the tape wound around the reel can be seen through the window. Use materials. Possible materials suitable for this purpose include acrylic styrene resin or polycarbonate resin. On the other hand, the hub top (47) is made of a material forming the hub (45).
) is in contact with the leaf spring which is the pressing means on the case side, and it is necessary to improve the slippage when fitting the reel holder into the hub hole (46), so it is abrasion resistant and has a small coefficient of friction. The resin material used is Possible materials suitable for this purpose include polyacetal resin or a mixed resin of polycarbonate resin and fluororesin. In addition, in this configuration, since the reference surface (48) on the hub side serves as a reference for determining the facing distance between the upper and lower flanges, the upper reel member (41) is overlapped with the upper end surface of the hub (45). A small distance d may be formed between the upper surface of the edge (45a) of the hub (45) and the lower surface of the corresponding upper flange (43).

Then, the upper reel member (41) and the lower reel member (42)
First, as shown in FIG. 5A, the upper reel member (4
1) with its reference surfaces (50) and (48) in contact with the upper end surface of the hub of the lower reel member (42), and each protruding piece (
49) are inserted into the corresponding engagement holes (51) and placed (the chain line shows the state before the up-wing member (41) is placed). After that, as shown in FIG. 5B, the engagement hole (51
) The tip (49a) of the protruding piece (49) facing the upper reel member (41) is heated and melted, that is, melted and expanded to be welded to the upper reel member (41).

When integrating the up-wing member (41) and the down-wing member (42), the reference plane (50) of both members (41) and (42)
) and (48), the reference planes (50) and (48) formed on both members (41) and (42) are maintained accurately, and the reference plane ( 50) and (48) to assemble a reel with accurate dimensions. In particular, the parallelism between the upper and lower flanges (43) and (44) can be achieved extremely accurately.

Furthermore, even when connecting the reel members (41) and (42), it is only necessary to melt the projection (49) formed on the member (42) on one side, so each reel member (41) and (42) need only be melted.
42) It is possible to create a good reel without being restricted in selecting a resin material suitable for the function. Next, tape (T) is wound around the reel, and the reel flange (
43) is placed in the cassette case (2) shown in FIGS. 1 and 2 so as to face the transparent window of the upper half (3), thereby assembling the desired tape cassette.

According to the present invention, both the upper and lower reel members (41) and (42)
) are selected for their respective functions, that is, a resin material with good transparency and a resin material with high wear resistance and a small coefficient of wear, but both the upper and lower flanges (43) and (4
4) A reel with good parallelism can be easily made.

Since the upper flange (43) of the reel is made of a highly transparent resin material, the tape winding state can be seen from outside the cassette. Also, glue hubs (4
5) and the lower reel flange (44) are made of a resin material with a low coefficient of friction and high wear resistance, so that attachment to and detachment from the reel holder can be performed extremely smoothly, and the lower reel flange (44) and Since the contact friction between the magnetic tapes to be wound and between the lower reel flange (44) and the cassette case (2) is small and wear is less likely to occur, the rotational drive of the reel and the running of the tape 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 wing member (42) by inserting each projection (49) into the corresponding engagement hole (51). , the upper flange (43) and the hub (45) are positioned,
The bonding position of both can be made constant. Even if subjected to high frequency vibration during subsequent welding, -F Furalane (43
) and the hub (45) do not rotate and cause positional deviation, and furthermore, even if external pressure is applied after the reel is assembled, the upper flange (43) is prevented from rotating relative to the hub (45). Therefore, the reliability of the reel and, by extension, the tape cassette can be improved.

In addition, since the tip of the protruding piece (49) is located lower than the top of the hub center top (47) and the top surface of the upper flange (43), the reel is housed inside the cassette case, and the hub center top (47) ) is pressed by the reel presser, there is no risk that the tip will come into contact with the reel presser, so good reel rotation can be achieved at the same time.

Although the case where the present invention is applied to a tape cassette for a VTR has been described above, 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, FIG. 3 is a cross-sectional view showing an assembled state of a conventional reel, and FIG. 4 is a perspective view showing an example of a tape cassette for a VTR according to the present invention. FIGS. 5A and 5B are cross-sectional views of essential parts showing an assembled state, respectively. (41) is the upper reel member, (42) is the lower reel member, (
43) is the upper flange, (44) is the lower flange, (45)
is a hub, (48) and (50) are reference surfaces, (49) is a protrusion, and (51) is an engagement hole.

Claims (1)

[Claims] 1. A cassette case having a transparent window in a part of the upper half;
It consists of a reel hub that is integrally molded with a lower reel flange from synthetic resin that has a low coefficient of friction and high wear resistance, and an upper reel flange that is molded from transparent synthetic resin.The upper end surface of the reel hub has multiple protrusions. The upper reel flange is provided with a plurality of engagement holes, the protrusion is passed through the engagement hole and these are integrated by heat melting, and the integrated reel is connected to the upper reel flange. A tape cassette, characterized in that the tape cassette is housed in the cassette case so as to face the transparent window of the upper half, so that the magnetic tape wound around the lower reel flange can be seen from outside the upper half. 2. A cassette case having a transparent window in a part of the upper half;
A reel hub is made of a synthetic resin with a low coefficient of friction and high wear resistance and is integrally molded with a lower reel flange, and an upper reel flange is made of a transparent synthetic resin and is provided on the upper end surface of the reel hub. A step of inserting a plurality of protrusions into a plurality of engagement holes provided in the upper reel flange, a step of integrating the upper reel flange into which the protrusions are inserted and the reel hub by heat melting, A method for assembling a tape cassette comprising the step of storing the reel in the cassette case so that the upper reel flange faces the transparent window of the upper half.