JPH0468712B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a tape cassette that is most suitable for application to a recording and reproducing apparatus such as a video tape recorder, and is particularly composed of an upper half and a lower half. A cassette housing in which the stored tape is passed along the front opening, and a front lid having a substantially U-shaped planar shape and a pair of fulcrum pins provided inside the left and right ends, A front cover is rotatably supported on both left and right walls of the cassette casing via the pair of fulcrum pins to cover the front side of the passed tape, and a coil portion is integrally provided approximately at the center. The torsion coil spring is inserted into the outer periphery of at least one fulcrum pin of the front lid by its coil portion, and both ends are respectively latched to the front lid and the cassette casing. This invention relates to a tape cassette that includes a torsion coil spring that biases the lid to rotate in the direction of closing the lid.

BACKGROUND TECHNOLOGY AND PROBLEMS The conventional method for assembling the cassette casing of this type of tape cassette is to insert a torsion coil spring around the outer periphery of one of the fulcrum pins of the front cover.
Place the pair of fulcrum pins on the front lid against the lower edges of the left and right walls of the upper half, fit the upper half together with the front lid onto the lower half, and connect the upper and lower halves together with screws, etc. It was a way to make it happen.

However, in this method, the upper half and the front cover are fitted onto the lower half without mechanically temporarily fixing them in any way, so the upper half and the front cover separate when they are fitted. Therefore, the upper half and the front lid were easily displaced from the lower half in both the front, rear, right and left directions. especially,
In order to impart rotational movement to the front cover in the direction of closing the cassette casing in the assembled state, it is necessary to twist the torsion coil spring to a certain extent to apply so-called initial stress. To do this, when the upper half and front cover are fitted onto the lower half, the rear end of the torsion coil spring is brought into contact with a predetermined abutment part on the lower half side against elasticity. There is a need. However, due to the above-mentioned misalignment, it becomes extremely difficult to bring the rear end of the torsion coil spring into contact with the abutting part, and as a result, assembling the cassette case becomes extremely troublesome. There is. Furthermore, with such a conventional method, it is difficult to introduce an automatic assembly machine to automatically assemble the cassette case.

OBJECTS OF THE INVENTION The present invention seeks to provide a tape cassette capable of correcting the above-mentioned defects.

Summary of the Invention The present invention provides the tape cassette described above.
A pair of recesses into which the pair of fulcrum pins of the front cover are to be fitted are provided on the lower edge of the left and right side walls of the upper half,
A locking protrusion at the front end of the torsion coil spring and a temporary fixing protrusion at the rear end of the torsion coil spring are provided at the front and rear sides of the fulcrum pin inside one end of the front cover, and one of the upper half The side wall of the torsion coil spring is provided with a slit for inserting the rear end of the torsion coil spring, and a temporary fixing protrusion for temporarily fixing the rear end inserted into the slit. With both front and rear ends of the torsion coil spring inserted into the outer periphery of the fulcrum pin being respectively locked to the locking protrusion and temporary fixing protrusion of the front cover, the pair of fulcrum pins of the front cover are The upper half is fitted into the pair of recesses, and in this state, the rear end of the torsion coil spring is inserted into the slit of the upper half against the elastic force, and the rear end is temporarily secured to the upper half. By fitting the upper half onto the lower half, the rear end of the torsion coil spring whose position is regulated within the slit is fixed to the lower half. The tape cassette is constructed so that it can be brought into contact with a predetermined contact part on the half side against elasticity, and the cassette case can be assembled extremely easily and accurately.

Embodiments Hereinafter, embodiments in which the present invention is applied to a tape cassette for a video tape recorder will be described with reference to the drawings.

First, the overall structure of the tape cassette will be explained with reference to FIGS. 1 to 4.

First, as shown in FIG. 1, a cassette housing 3 composed of upper and lower halves 1 and 2, a front lid 4, and a rear lid 5 are each molded from synthetic resin. Then, the magnetic tape 8 is wound around a pair of left and right reels 6 and 7.
are housed in the upper and lower halves 1 and 2, and these upper and lower halves 1 and 2 are fitted into each other from above and below and connected together with a plurality of screws to form a cassette housing 3.
is configured. A front opening 10 is provided on the front surface of the cassette housing 3 over the entire length in the left and right direction, and a pair of openings 10 are formed integrally within the cassette housing 3 at positions near both left and right ends of the front opening 10. A magnetic tape 8 is guided by a tape guide 11 and passed along a front opening 10 as shown in FIGS. 2 and 4. Further, a recess 12 is formed in the cassette housing 3 on the rear side of the front opening 10 inside the pair of tape guides 11.
2 is partitioned off from the housing side of both reels 6 and 7 in the cassette casing 3 by a partition wall 13 integrally molded inside the cassette casing 3 and having a substantially U-shaped planar shape. . Note that both the top and bottom of this recess 12 are open.

Next, the front cover 4 has a substantially U-shaped planar shape as shown in FIG. 1, and a pair of fulcrum pins 15 are integrally molded on the inside of both left and right ends 4a so as to be coaxial with each other. . As shown in FIGS. 2 to 4, the front cover 4 is attached to the left and right side walls of the cassette housing 3 by its pair of fulcrum pins 15 in order to cover the front side of the magnetic tape 8 that is being passed along the front opening 10. 3
The front cover 4 is attached to the cassette case by being inserted into a pair of pin insertion holes 16 that are provided on the front end side of the cassette case 16 on the same axis. It is attached to body 3.

Next, as shown in FIG. 1, the rear lid 5 has an upper lid 17 integrally molded along its upper edge, and a pair of fulcrum pins are provided at approximately the center of the left and right edges of the rear lid 5 in the vertical direction. 18 are integrally molded with each other on the same axis. As shown in FIGS. 2 and 4, the rear cover 5 is disposed in a recess 12 parallel to the front cover 4 to cover the rear side of the magnetic tape 8 that is passed along the front opening 10. . In addition, this rear lid 5
As shown in FIGS. 1 and 4, the pair of fulcrum pins 18 are inserted into the pair of pin insertion holes 20 of a pair of protrusions 19 that are integrally molded near the left and right ends 4a on the rear surface of the front cover 4. The rear cover 5 is attached to the front cover 4 by being inserted from the inside so that it can rotate up and down about both fulcrum pins 18. Note that the upper lid 17 has a recess 1 as shown in FIGS. 2 and 4.
It is arranged to cover the upper surface of 2.

Next, as shown in FIGS. 1 and 2, the left and right end portions 13a of the partition wall 13 are opposed in parallel from the left and right directions, and the opposing surfaces of the left and right end portions 13a have a gentle S-shape. A pair of bent guide grooves 21 are provided. Further, the upper ends 21a of both guide grooves 21 are open upward. A pair of protrusions 22 are integrally molded on the rear surface of both left and right edges of the rear cover 5 below both fulcrum pins 18, and a pair of protrusions 22 are integrally molded on the outside of both protrusions 22 so as to be coaxial with each other. A guided pin 23 is loosely fitted into both guide grooves 21. Further, as shown in FIGS. 2 and 3, one end 4a of the front cover 4 and one side wall 3 of the cassette housing 3 are connected to the outer periphery of one fulcrum pin 15.
A torsion coil spring 25 is wound between the torsion coil spring 25 and the coil part 25a provided approximately at the center thereof, and the front end 25b of the torsion coil spring 25 is connected to one end 4a of the front cover 4. It is pressed against a spring locking protrusion 26 that is integrally formed at a position in front of the fulcrum pin 15 inside the fulcrum pin 15 . Further, as shown in FIGS. 1 and 3, one side wall 4 of the cassette housing 3 is connected to the rear side of one fulcrum pin 15 around which a torsion coil spring 25 is wound.
A lock lever 28 is attached to a to be rotatable in the front-back direction. This lock lever 28 is molded from synthetic resin, and its upper end 28
A fulcrum pin 29 is integrally molded near the front lower part of a, a lock pawl 30 is integrally molded at the front end, and an unlocking protrusion 31 is integrally molded at the lower end. The lock lever 28 is inserted by its fulcrum pin 29 into a pin insertion hole 32 provided in the side wall 4a, and is attached so as to be rotatable in the front and rear directions about the fulcrum pin 29. As shown in FIG.
is pressed onto the upper end 28a of. Therefore, the torsion coil spring 25 rotates the front cover 4 in the direction of closing the lid, which is the direction of arrow a in FIG. It is rotationally energized. and the third
As shown by the solid line in the figure, the lock claw 3 of the lock lever 28 is attached to a lock protrusion 33 that is integrally molded inside one end 4a of the front cover 4 at a position rearward of the fulcrum pin 15.
0 is engaged from below to lock the front lid 4 in the closed position.

According to the tape cassette constructed as described above, when the cassette is not in use, the front lid 4 is locked in the closed state by the lock lever 28 as shown by the solid line in FIG. In this lid closed state, the magnetic tape 8 passing along the front opening 10 is covered by the front lid 4 and the rear lid 5 from the front and back, as shown by the solid line in FIG. It is a so-called completely sealed tape cassette.

Next, when the tape cassette is installed in the video tape recorder, the lock release member 35 is pressed against the lock release projection 31 of the lock lever 28, as shown by the imaginary line in FIG. The front cover 4 is rotated in the direction of arrow b', which is the unlocking direction, against the rotational force, and the front cover 4 is unlocked, and the front cover 4 is pushed up by the cover opening member 36, and the front cover 4 is The torsion coil spring 25 resists the direction of the arrow a', which is the lid opening direction.
The front opening 10 is opened by rotating 90 degrees. The front cover 4 is then rotated about 90 degrees in the direction of arrow a' from the closed position shown by solid lines in FIG. 4 to the open position shown by phantom lines about both fulcrum pins 15. Therefore, since both fulcrum pins 18 of the rear cover 5 are also rotated in the same direction and at the same angle, the rear cover 5 and the front cover 4 also rotate at the same angle.
The lid is rotated from a closed position shown by a solid line to an open position shown by a phantom line in the figure. At this time, by rotating both fulcrum pins 18 in the direction of arrow a', both guided pins 23 are guided by both guide grooves 21 and moved in the direction of arrow c, and both guide grooves 21 Due to the guiding action of the rear cover 5, the rear cover 5 is rotated about both fulcrum pins 18 with respect to the front cover 4 in the direction of the arrow d, which is the direction of separating the front cover 4 to the rear, and the rear cover 5 is opened in the direction of the arrow a'. It's going to be covered. Also, when the lid is closed,
In the reverse operation when the lid is opened, the front lid 4 is rotated in the direction of arrow a in FIG. 4, and the rear lid 5 is rotated in the direction of arrow d' with respect to the front lid 4. The guided pin 23 also moves in the direction of the arrow c' within the guide groove 21, and is moved back to the lower end of the guide groove 21 shown by the solid line in FIG.

Next, as shown in FIGS. 5A to 7, the cassette housing 3 is
The assembly structure and assembly method will be explained.

First, Figures 5A to 5C show the front cover 4 on the upper half 1.
In these figures, the upper half 1 and the front lid 4 are shown upside down. Further, it is assumed that the rear lid 5 is already rotatably attached to the inside of the front lid 4.

Next, as shown in FIG. 5A, the pair of recesses 41 into which the pair of fulcrum pins 16 of the front cover 4 are to be fitted are located at the lower edges 1b (facing upward in the figure) of the left and right side walls 1a of the upper half 1. It is provided. Then, the torsion coil spring 25 is inserted into the outer periphery of one of the fulcrum pins 15 of the front lid 4 by its coil portion 25a, its front end 25b is locked with the spring locking projection 26, and the rear end 25c is It is locked to a locking protrusion 33 which also serves as a spring temporary fixing protrusion.

Next, in this state, when the front cover 4 is inserted into the upper half 1 from the direction of the arrow e as shown in FIG.
After sliding on the top, they are simultaneously fitted into the recess 41 as shown in FIG. 5C. The process of inserting the front cover 4 into the upper half 1 from the direction of the arrow e and fitting the fulcrum pins 15 into the recesses 41 can be carried out extremely easily using an automatic assembly machine.

Next, as shown in Fig. 5C and Fig. 6, the upper half 1
On the outer surface of one of the side walls 1a, at a position rearward from the recess 41, there is integrally provided a temporary fixing protrusion 42 having a substantially wedge shape as shown in FIG.

Therefore, after fitting both fulcrum pins 15 into both recesses 41 as shown in FIG. 5B, the rear end portion 25c of the torsion coil spring 25 is moved in the direction of arrow f against its elasticity, as shown in FIG. 5C. Push it in. Then, the torsion coil spring 25 is slightly twisted against its elasticity (spring force), and the rear end 25c near the coil portion 25a is placed under the temporary fixing protrusion 42 as shown by the imaginary line in FIG. 5C. It is pushed in and temporarily secured as shown in FIG. Note that the process of pushing the rear end portion 25c of the torsion coil spring 25 in the direction of the arrow f and locking it to the temporary fixing protrusion 42 can be performed extremely easily by an automatic assembly machine.

With the above steps, the front lid 4 is temporarily fixed to the upper half 1,
Thereafter, even if the upper half 1 and the front cover 4 are oriented in the normal vertical direction as shown in FIG. 5D, the front cover 4 will not fall off below the upper half 1. That is, in the temporarily fixed state shown in FIG. 5C, the front cover 4 is attached to the torsion coil spring 2.
The upper end 4b of the front side of the front cover 4 is bent almost rearward into an L-shape,
The upper end portion 4b is brought into contact with the front end portion 1c of the left and right side walls 1a of the upper half 1, and rotation of the front cover 4 in the direction of arrow a is restricted, and the front cover 4 is held (temporarily) on the upper half 1. be stopped).

On the other hand, as shown in FIGS. 6 and 7, the outer surface of one side wall 1a of the upper half 1 has a temporary fixing protrusion 42, and the rear side has a roughly U-shaped cross section that is open in two directions, forward and downward. A U-shaped wall 43 is integrally formed with the rear end 2 of the torsion coil spring 25.
5c is pushed in the direction of arrow f as shown by the imaginary line in FIG. 5C and is locked to the temporary fixing protrusion 42, the rear end portion 25c is attached to the U-shaped wall 43 as shown in FIGS. 7 and 6. Slit 4 provided inside the
It is inserted within 4. And thereafter, the rear end portion 25c
is regulated within the slit 44 in the left-right direction with respect to the side wall 1a of the upper half 1 (indicated by the arrow g in FIG. 7).
direction) is prevented from moving. At this time, since a pair of inclined guide surfaces 45 that spread downward are provided on both left and right edges of the lower end of the slit 44,
When inserting the rear end 25c into the slit 44, the rear end 25c is guided by both inclined guide surfaces 45 and inserted smoothly into the slit 44.

Next, after temporarily fixing the front cover 4 to the upper half 1 as described above, the upper half 1 and the front cover 4 are lowered from above the lower half 2 in the direction of arrow k to fit together, as shown in FIG. 5D. 3 is assembled, and the rear end 25c of the torsion coil spring 25 is placed on the upper end 28a of the lock lever 28, which is the contact part on the lower half 2 side. The contact is made extremely easily and accurately against the elasticity (spring force) of the spring 25. Note that when fitting the upper half 1 onto the lower half 2, the front cover 4 is attached as shown in FIG. 5D.
torsionally rotate it at a predetermined angle in the direction of arrow a' against the coil spring 25, and then rotate both guided pins 23 of the rear cover 5.
are aligned with the upper ends 21a of both guide grooves 21 of the lower half 2, and as the upper half 1 is fitted onto the lower half 2, both guided pins 23 are aligned with the upper ends 21a of both guide grooves 21 of the lower half 2.
It is inserted into the interior from its upper end 21a.

However, at this time, as shown in FIGS. 6 and 7, the outer side of one side wall 2a of the lower half 2 has a substantially U-shaped cross section that is open in three directions: forward, upward, and downward. A U-shaped wall 47 is integrally molded, and a pair of recesses 48 are formed inside the upper edge of the U-shaped wall 47.
is provided. The lock lever 28 has a slit 49 provided inside the U-shaped wall 47.
The right and left ends of the fulcrum pin 29 are inserted into the recesses 48 and locked. When the upper half 1 is fitted onto the lower half 2, the U-shaped wall 43 of the upper half 1 is fitted onto the U-shaped wall 47 of the lower half 2 as shown in FIG.
The upper end 28a of the lock lever 28 is relatively inserted into the slit 44 of the upper half 1 from below,
The rear end 25c of the torsion coil spring 25, whose position is restricted within the slit 44, comes into contact with the upper end 28a of the lock lever 28 against elasticity.

Therefore, the abutting action of the rear end 25c of the torsion coil spring 25 on the upper end 28a of the lock lever 28 can be performed within the slit 44 of the upper half 1 that restricts the position of the rear end 25c. , the rear end 25c abuts against the upper end 28a of the lock lever 28 very simply and accurately against elasticity. Incidentally, as shown in FIG. 7, the widths L ₁ and L 2 in the left and right directions of the slits 44 and 49 of the upper and lower halves 1 and ₂ are approximately equal, and the width in the left and right direction of the upper end portion 28a of the lock lever 28 is approximately the same.
_L3 is also formed to have dimensions as close as possible to these _L1 and _L2 .

Furthermore, when assembling the cassette case 3 as described above, the front cover 4 is fitted onto the lower half 2 together with the upper half 1 while being temporarily fixed to the upper half 1. At times, it is difficult to separate the upper half 1 and the front lid 4 into pieces. As a result, it is difficult for the upper half 1 and the front cover 4 to be unexpectedly misaligned with respect to the lower half 2 both in the front, back, left and right directions, and they can be fitted together extremely easily and accurately. It should be noted that the process of fitting the upper half 1 together with the front cover 4 onto the lower half 2 in this way can be carried out extremely easily by an automatic assembly machine.

After fitting the upper and lower halves 1 and 2 and the front cover 4 as described above, the upper and lower halves 1 and 2 are fastened together with a plurality of screws and joined together to form the cassette housing 3. The assembly is completed, but as described above, the rear end 25c of the torsion coil spring 25 is brought into contact with the upper end 28a of the lock lever 28 against elasticity, so that the torsion coil spring 25
is twisted into a predetermined state, and the torsion coil spring 25
is given an initial stress in a predetermined state. As a result, the front cover 4 and the lock lever 28 are urged to rotate in the directions of arrows a and b in FIG. 3, respectively, by a predetermined force.

Furthermore, by fitting the upper and lower halves 1 and 2 from above and below, as shown in FIG.
Both recesses 41 provided at the lower end edge 1b are closed by the upper end edges 2b of both side walls 2a of the lower half 2, and both recesses provided at the upper end edge of the U-shaped wall 47 of the lower half 2. 48 is closed at the lower end edge of the U-shaped wall 43 of the upper half 1. Therefore, both fulcrum pins 15 of the front cover 4 and the fulcrum pin 2 of the lock lever 28
The left and right end portions of 9 are rotatably supported between both side walls 1a and 2a of the upper and lower halves 1 and 2, respectively, while being sandwiched from above and below. Incidentally, the process of screwing the upper and lower halves 1 and 2 can be carried out extremely easily using an automatic assembly machine.

In the embodiment described above, the rear end 25c of the torsion coil spring 25 is connected to the lock lever in order to use one torsion coil spring 25 as the two rotation urging means for the front cover 4 and the lock lever 28. 28, the contact portion on the lower half 2 side in the present invention is not necessarily limited to the upper end portion 28a of the lock lever 28, but may be provided on the side of the lower half 2. The contact portion may have any structure and shape.

Application Example Although one embodiment of the present invention has been described above, the present invention can be applied to tape cassettes for various recording and reproducing devices other than video tape recorders and various other information processing devices.

Effects of the Invention The present invention is configured such that the front cover is temporarily attached to the upper half and then fitted onto the lower half as described above, so that the front cover and the upper half are separated into pieces when they are fitted together. This makes it possible to fit the upper half onto the lower half very easily and precisely without causing any misalignment with the front lid.

Moreover, in particular, with the front cover temporarily attached to the upper half, the rear end of the torsion coil spring is inserted into the slit provided in the upper half to regulate its position.
When fitting the upper half onto the lower half, the rear end of the torsion coil spring is regulated in position within the slit, and then the torsion coil spring is placed on a predetermined abutment part provided on the lower half side to resist elasticity. Since the structure is configured such that the contact is brought into contact with each other, the contact can be performed extremely easily and accurately.

Therefore, according to the present invention, it is possible to assemble the cassette case extremely easily and accurately, and also,
There is a great advantage that an automatic assembly machine can be easily introduced and the automatic assembly of the cassette case can be easily performed.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a tape cassette for a video tape recorder, in which FIG. 1 is an exploded perspective view of the whole, FIG. 2 is a plan view of the same fully assembled state, and FIG. Figure 2-
FIG. 4 is an enlarged partially cutaway side view taken along the line shown in FIG. 2, and FIGS. 5A to 5
Figure D is the third figure explaining how to assemble the cassette case.
FIG. 6 is an exploded perspective view of essential parts, and FIG. 7 is an enlarged sectional view taken along the line of FIG. 3. In addition, in the symbols used in the drawings, 1...upper half, 1a...both side walls of the upper half, 1b...lower edge of the upper half, 2...lower half, 2a...both side walls of the lower half, 2b... ...Top edge of lower half, 3...
...Cassette housing, 4...Front lid, 6, 7...Reel, 8...Magnetic tape, 10...Front opening, 1
5, 29... Fulcrum pin, 25... Torsion coil spring, 25a... Coil portion of torsion coil spring, 25
b...front end of the torsion coil spring, 25c...rear end of the torsion coil spring, 26...spring locking protrusion,
28... Lock lever, 28a... Upper end of lock lever, 33... Locking protrusion (spring temporary fixing protrusion), 41, 48... Recess, 42... Temporary fixing protrusion, 44, 49... Slit .

Claims (1)

[Claims] 1. A cassette casing consisting of an upper and lower half, in which the stored tape is passed along the front opening, and a planar shape that is approximately U-shaped, and a pair of fulcrum pins inside the left and right ends. a front lid rotatably supported on both left and right walls of the cassette casing via the pair of fulcrum pins to cover the front side of the passed tape; It is a torsion coil spring having a coil part integrally provided in the center thereof, and the coil part is inserted into the outer periphery of at least one fulcrum pin of the front cover, and both ends are connected to the front cover and the cassette. In the tape cassette, the tape cassette is comprised of torsion coil springs that are respectively locked to a housing and rotate and bias the front lid in the closing direction, and a pair of recesses into which the pair of fulcrum pins of the front lid are fitted. are provided on the lower edge of the left and right side walls of the upper half, and the locking protrusion of the front end of the torsion coil spring and the rear end of the torsion coil spring are provided at the front and rear sides of the fulcrum pin inside one end of the front lid. A slit for inserting the rear end of the torsion coil spring into one side wall of the upper half, and a temporary fixing protrusion for temporarily securing the rear end inserted into the slit. A locking projection is provided, and both front and rear ends of the torsion coil spring inserted into the outer periphery of the fulcrum pin by the coil portion are respectively locked to a locking projection and a temporary locking projection of the front cover. In this state, the pair of fulcrum pins of the front cover are fitted into the pair of recesses of the upper half, and in this state, the rear end of the torsion coil spring is inserted into the slit of the upper half against elastic force. The rear end of the upper half is fitted onto the lower half, and the position is regulated within the slit by fitting the upper half onto the lower half. A tape cassette characterized in that the rear end portion of the torsion coil spring can be brought into contact with a predetermined contact portion on the lower half side against elasticity.