JPS633032Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape cartridge, and more particularly to a magnetic tape cartridge incorporating a reel rotation stopper.

For example, in magnetic tape cartridges for VTRs, in order to prevent the magnetic tape from sagging when the magnetic tape cartridge is not in use, a rotation stopper is installed inside the cartridge case to stop the rotation of the reel on which the magnetic tape is wound. It is installed in

As shown in FIG. 41, this conventional rotation stopper is provided on the rear wall 202 side of the lower case 201 of the cartridge case, and has one release pin insertion hole 203 and one claw member for rotation. lever 20
4, two claw members 205, and two coil springs 206. The release pin insertion hole 203 is formed approximately at the center of the lower case 201 near the rear wall 202, and is a dedicated hole into which a release pin (not shown) is inserted. The lever 204 for rotating the claw member includes a tongue piece 207 that closes the upper opening of the release pin insertion hole 203, a cylindrical part 208 connected to the root of the tongue piece 207, and a tongue piece 207 from the cylindrical part 208.
Two pressing portions 209 erected at almost right angles to the
It is made up of. This lever for rotating the claw piece member 2
04 is rotatably mounted on two jetties 210 extending from the rear wall 202 toward the release pin insertion hole 203. The claw piece member 205 is attached to the lower case 20
1, a tubular body portion 212 rotatably fitted onto a shaft 211 protruding from the shaft 211, and a lever 20 for rotating the claw member.
an arm portion 213 that comes into contact with the pressing portion 209 of No. 4;
It consists of a claw piece 215 extending toward the reel 214 side. A coil spring 206 is attached to the upper end of the shaft 211.
is fitted, one end of which is locked to a locking pin 216 protruding from the lower case 201, and the other end is locked to a claw piece 215 of the claw piece member 205. Due to the elasticity of the coil spring 206, the claw piece 2 of the claw piece member 205
15 is biased toward the reel 214, and the tongue piece 207 is biased toward the release pin insertion hole 203. A large number of tooth grooves 218 are formed on the outer periphery of the flange 217 of the reel 214, and the claw pieces 215
When the tip of the reel 21 fits into the tooth groove 218, the reel 21
4 rotation is stopped.

When this magnetic tape cartridge is installed in a recording and reproducing device, the two reference pins bored in the front side of the lower case 201 of the magnetic tape cartridge are moved as the magnetic tape cartridge is lowered relative to the recording and reproducing device. A reference pin (not shown) provided in the recording/reproducing device is inserted into the insertion hole 219 to position the magnetic tape cartridge. On the other hand, a rotation stop release pin provided in the recording/reproducing apparatus is inserted into the release pin insertion hole 203, and the tongue piece 207 is pushed up against the elasticity of the coil spring 206 due to the insertion. As a result, the pressing portion 209 of the claw member rotation lever 204 is pushed down toward the rear wall 202, and accordingly, the claw member 205 rotates around the shaft 211, and the claw member 205 rotates around the shaft 211.
5 moves away from the tooth groove 218 of the reel 214, and the rotation stop of the reel 214 is released.

However, in the conventional magnetic tape cartridge, the release pin insertion hole 203 is provided separately from the reference pin insertion hole 219, so a space is required for each opening in the lower case 201, which is an obstacle to miniaturization of the magnetic tape cartridge. It was becoming. Further, in the conventional rotation stop device, each part has a complicated shape and structure, and the mold design and assembly work for the parts is complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic tape cartridge that overcomes the drawbacks of the prior art, is suitable for downsizing, and is capable of reliably releasing the reel from rotation.

In order to achieve this objective, the present invention forms a substantially dogleg-shaped bent part between the rotation support part and the claw part of the rotation stopper, and also forms a bent part in the cartridge case. The tip of the reference pin, which is inserted into the cartridge case through the reference pin insertion hole, comes into contact with the bent portion, thereby causing the claw portion of the rotation stopper member to contact the reel. The feature is that it is configured to release the engagement with the tooth groove.

Next, embodiments of the present invention will be described in detail with reference to figures. A cartridge case is composed of a lower case 1 and an upper case 2, and a rotating lid 3 is rotatably supported on the front side of the cartridge case. Both lids 3 are molded from synthetic resin.

Approximately in the center of the lower case 1 are the figures 4 and 6.
As shown in the figure, two drive shaft insertion holes 4 are bored at a predetermined interval. A pair of reels 6 for winding the magnetic tape 5 are arranged above the drive shaft insertion hole 4, respectively. On the outer periphery of the reel 6, there are front inner walls 7A, 7B and a rear inner wall 8 with a slight gap between them.
A, 8B, 8C are provided, and these inner walls 7, 8
is formed integrally with the lower case 1. Front inner wall 7
A and 7B are connected to each other, and the front wall 9
It is also connected to A, 9B, and 9C. In FIG. 4, the rear inner walls 8A and 8C at the left and right ends are connected to the side wall 10 and the rear wall 11 of the lower case 1, and the rear inner wall 8B at the center is connected to the rear wall 11, respectively. The rear inner wall 8B in the center is higher than the rear wall 11, and after joining the lower case 1 and the upper case 2, the rear inner wall 8B
The upper end of the upper case 2 extends close to the inner surface of the upper case 2.

An erroneous erasure prevention piece 13 is integrally formed on the bottom surface of the lower case 1 so as to face the inside of the chamber 12B defined by the rear inner wall 8B and the rear wall 11 at the center. As shown in FIG. 7, the root portion of the accidental erasure prevention piece 13 is slightly thinner and can be easily separated from the lower case 1. When the erroneous erasure prevention piece 13 is folded up, it is separated from the lower case 1 and housed in the chamber 12B, so that the magnetic tape 5 is not damaged by the erroneous erasure prevention piece 13 separated from the lower case 1.
The rotation of the reel 6 is not hindered.

Inside the chamber 12A defined by the rear inner wall 8A, the side wall 10, and the rear wall 11 on the left side, a boss portion 14A for tightening screws and a pivot shaft 15A protrude, and a slightly elongated reference pin insertion hole 16A is provided. An arc-shaped guide groove 17A is formed on the upper surface of the lower case 1 and is opened toward the lower surface of the lower case 1 and is centered on the pivot shaft 15A. On the other hand, a boss portion 14B and a pivot shaft 15B are protrudingly provided in a chamber 12B defined by the rear inner wall 8C, the side wall 10, and the rear wall 11 on the right side, and a circular reference pin insertion hole 1
6B, and an arcuate guide groove 17B is formed, and these are arranged at positions symmetrical to the left boss portion 14A, pivot 15A, reference pin insertion hole 16A, and guide groove 17A.

A rotation stopper member 18B is rotatably fitted to the pivot 15B. The rotation stopper 18B is molded from synthetic resin with a small coefficient of friction, and includes a sleeve 19B that fits around the pivot shaft 15B, a receiving portion 20B extending in one direction from the outer periphery of the sleeve 19B, and the receiving portion 2.
It is composed of a claw portion 21B provided at the tip of the 0B. The lower end of the claw portion 21B protrudes slightly from the lower ends of the sleeve 19B and the receiving portion 20B, so that when the rotation stopper 18B is fitted to the pivot shaft 15B, the lower end of the claw portion 21B enters into the guide groove 17B. . With the rotation stopper 18B pivotally attached to the pivot 15B, the reference pin insertion hole 1 of the receiving portion 20B
A bent portion 22B having a dogleg shape in plan view is provided at a portion facing 6B. Further, an inclined portion 23B having an inclination angle of approximately 30 to 60 degrees is formed inside the lower end of the receiving portion 20B.

A rotation stopper member 18 pivotally attached to the left pivot shaft 15A
As shown in FIG. 10, A is symmetrical to the right-side rotation stop member 18B described above.
Similarly, the sleeve 19A, the receiving portion 20A, and the claw portion 21A
The receiving portion 20A has a bent portion 22 at its middle portion.
A is provided, and an inclined portion 23A is formed at the lower end.

A spring member 24B made of a coil spring is loosely fitted onto the pivot shaft 15B from above the rotation stopper 18B. As shown in FIG. 8, this spring member 24B has an annular portion 25 formed by multiple windings in the middle.
Both ends extending from the annular portion 25 are bent in the same direction as the height direction of the annular portion 25 to form elastic contact ends 26A and 26B. Spring member 24
With the elastic contact ends 26A and 26B slightly pressed against each other against the elasticity of
B is inserted into the gap between the side wall 10 and the receiving portion 20B, and then the elastic contact ends 26A and 26B are released. Then, due to the restoring force of the spring member 24B, the elastic contact end 26A is elastically engaged with the outer surface of the receiving portion 20B, and the elastic contact end 26B is elastically engaged with the inner surface of the side wall 10. is elastically biased toward the reel 6 side. With this structure, the spring member 24 can be easily mounted and supported.

The reel 6 has a hub 27 as shown in FIG.
It consists of a lower flange 28 and an upper flange 29 integrally projecting from each other. Lower flange 2
Reference numeral 8 is made of opaque synthetic resin, and a large number of tooth grooves 30 are formed at predetermined intervals around the entire circumference.

12 and 14 on the outer periphery of the hub 27.
As shown in the figure, a concave tape fixing piece fitting portion 31 that opens toward the outer peripheral surface of the hub 27 is formed. At the bottom of this tape fixing piece fitting part 31, there is a
More than one tape clamping part 32 is provided in a protruding manner, and locking protrusions 33 are formed on both sides, respectively. On the other hand, the magnetic tape 5 is attached to this tape fixing piece fitting portion 31.
The tape fixing piece 34 (see FIG. 14) that is fitted through the end of the tape clamping part 3
The portion facing 2 has a flat lower end surface 35, and elastic protrusions 36 with some flexibility are provided on both sides of the lower end surface 35. Therefore, if the tape fixing piece 34 is pushed into the tape fixing piece holding part 31 through the end of the magnetic tape 5, the elastic protrusions 3 on both sides
The tape fixing pieces 6 pass over the respective locking protrusions 33 while being pressed and deformed inwardly, and the tape fixing pieces 34 fit into the tape fixing piece fitting parts 31. Once the tape fixing piece 34 is fitted in this way, the stopper action of the locking protrusion 33 causes the tape fixing piece 34 to
4 will not come off from the tape-fixed piece clamping part 31. Then, the magnetic tape 5 is inserted between the tape holding part 32 and the lower end surface 35 of the tape fixing piece 34 by pushing in the tape fixing piece 34, and between the elastic protrusion 36.
The end of the magnetic tape 5 is fixed to the hub 27 by being firmly clamped between the elastic protrusion 36 and the locking protrusion 33 by the elastic force of the magnetic tape 5 .

As shown in FIGS. 11 and 12, the hub 2
A welding protrusion 37 for fixing the upper flange 29 to the hub 27 and a central protrusion 38 of the reel 6 are provided on the upper part of the reel 7 . On the other hand, the upper flange 29 made of transparent synthetic resin has these welding protrusions 3.
7 and a protrusion insertion hole 39 into which the central protrusion 38 is inserted (see FIG. 11). After inserting the welding protrusion 37 and the center protrusion 38 into the protrusion insertion hole 39, the upper end of the welding protrusion 37 is thermally melted to form the upper flange 29.
is fixed to the hub 27. The central protrusion 38 passes through the protrusion insertion hole 39 and projects from the upper flange 29.

As shown in FIG. 13, a drive shaft insertion recess 40 into which a drive shaft of a recording/reproducing device is inserted is formed on the lower side of the hub 27, and a drive shaft insertion recess 40 is formed on the circumferential surface of the drive shaft insertion recess 40 for a drive force transmission engagement. A plurality of stop ridges 41 are provided at predetermined intervals. Lower reel 6 to case 1
2, the drive shaft insertion recess 40 is placed above the drive shaft insertion hole 4 of the lower case 1, as shown in FIG.

Next, stopping and releasing the rotation of the reel 6 will be explained. As mentioned above, move reel 6 to upper case 1.
The rotation stopper member 18 and the spring member 24 are respectively fitted to the pivot shaft 15, and the claws 21 of the rotation stopper 18 are fitted into the outer tooth grooves of the reel 6 by using the elasticity of the spring member 24. 30, the reel 6 is stopped from rotating.
is above the reference pin insertion hole 16. This state is shown in FIGS. 4, 9, and 15, respectively.

When the magnetic tape cartridge is inserted into the recording and reproducing device and lowered, the tip of the reference pin 42 (see FIGS. 9 and 16) protruding from the recording and reproducing device passes through the reference pin insertion hole 16. , abuts against the lower end of the receiving portion 20 of the rotation stopper member 18. Receiving part 2
Since the inclined part 23 is provided at the lower end of 0,
By pushing up the reference pin 42, the receiving portion 20 is pushed away against the elasticity of the spring member 24, and thereby the rotation stopper 18 rotates about the pivot 15 toward the rear wall 11 of the lower case 1. . Along with this rotation, the claw portion 21 moves toward the outer peripheral tooth groove 30 of the reel 6.
The rotation of the reel 6 is released (see FIG. 16).

By providing the bent portion 22 in the portion of the receiving portion 20 that faces the reference pin insertion hole 16, the rotation stopper 18 can be smoothly and reliably engaged with the reference pin 42.

Further, by fitting the reference pins 42 into the reference pin insertion holes 16A and 16B of the lower case 1, the magnetic tape cartridge is installed at a predetermined position (reference position) of the recording/reproducing apparatus. At this time, due to the elasticity of the spring member 24, the left and right rotation stopper members 18
Since the pins A and 18B are brought into elastic contact with the outer periphery of each reference pin 42, the positioning of the magnetic tape cartridge becomes more reliable.

When taking out the magnetic tape cartridge from the recording/reproducing apparatus, the reference pin 42 is inserted into the reference pin insertion hole 1.
6, the rotation stopper member 18 is rotated toward the reel 6 by the restoring force of the spring member 24, and the claw portion 21 again fits into the outer tooth groove 30 of the reel 6, thereby stopping the rotation of the reel 6. .

In this embodiment, the receiving portion 20 of the rotation stopping member 18 is provided with a bent portion 22 having a dogleg shape in plan view, but other bending portions having an approximately Ω-shaped plan view may also be provided. Further, in the embodiment, the inclined portion 23 was provided over almost the entire length of the lower end of the receiving portion 20;
3 may be provided only at the bent portion 22 and the lower end in the vicinity thereof.

As shown in Figures 3, 5 and 17,
Below the front wall 9B of the lower case 1, at a position slightly offset from the center of the lower case 1, there is provided an erroneous insertion prevention piece fitting groove 43 into which an erroneous insertion prevention piece (not shown) of the recording/reproducing device is inserted. There is. In order to provide the one-piece fitting groove 43 to prevent incorrect insertion, a mountain-shaped protuberance 44 is formed at the bottom of the lower case 1. The portion of the protruding portion 44 that protrudes forward from the front wall 9B serves as a supporting protrusion to prevent the magnetic tape 5 from sagging, and when the magnetic tape 5 is stopped, it extends along the front surface of the magnetic tape cartridge. The middle part of the extended magnetic tape 5 is supported in a slightly raised state by a raised part 44 (see Fig. 8, Fig. 1).
(See Figure 7).

Behind the front wall 9B of the raised portion 44 is the front wall 9B.
Two bearing ridges 45 are protruded and extend substantially parallel to the ridges, a groove-shaped bearing portion 46 is formed on the upper surface of the bearing ridges 45, and a lock lever 47 is rotatably mounted between the bearing ridges 45. ing. Further, a release pin insertion hole 48 having a slightly elongated hole shape is bored near the raised portion 44 .

The lock lever 47 is molded from synthetic resin, and as shown in FIGS. 18, 19, and 20, a rotating pin 49 is protruded from approximately the center of each side of the lock lever 47. 49 is fitted into the bearing portion 46 of the bearing ridge 45. Since the depth of the bearing portion 46 is designed to be approximately the same as the diameter of the pivot pin 49, the pivot pin 49 is accommodated within the bearing portion 46 without protruding from the upper surface of the support ridge 45.
Two bearing jetties 62 are provided on the inner surface of the upper case 2 so as to face the bearing jetties 45 of the lower case 1 (see FIG. 30).
The bottom surface is flat. By joining the lower case 1 and the upper case 2, the pivot pin 49 is rotatably supported between the support projections 45 and 62 without rattling. (See Figure 19).

A portion of the lock lever 47 in front of the pivot pin 49 is stepped down and is integrally formed with a pressing portion 50 that extends to the upper end opening of the release pin insertion hole 48 .
On the other hand, a stopper portion 51 that projects upward is provided behind the pivot pin 49 of the lock lever 47. A leaf spring 63 bent into an accordion shape is inserted between the stopper portion 51 of the lock lever 47 and the retreated portion of the front wall 9B. Due to the pressing force of the leaf spring 63, the pressing portion 50 moves the lock lever 47 in the direction of closing the release pin insertion hole 48.
is elastically biased. The joint between the stopper part 51 of the lock lever 47 and the leaf spring 63 is slidable, and the stopper part 51 can be tilted toward the leaf spring 63 while compressing the leaf spring 63.
This lock lever 47 prevents the rotation (opening) of the rotating lid 3 disposed on the front side of the cartridge case consisting of the lower case 1 and the upper case 2, and prevents the rotating lid 3 from rotating (opening) the magnetic tape cartridge. Used to lock the closed state of the

As shown in FIGS. 21, 22, and 23, the rotating lid 3 is composed of a front plate 52, a top plate 53, and end plates 54 on both sides. A pin 55 and a second pivot pin 56 are provided on the right end plate 54 and project inward, respectively. By fitting these pivot pins 55 and 56 into support holes 57 (see FIG. 36) drilled on both sides of the upper case 2, the rotating lid 3 is rotatably supported by the upper case 2. . The rotating lid 3 is loosely fitted onto the first pivot pin 55 as shown in FIG. It is always elastically biased in the closing direction by the coil spring 65.

As shown in FIGS. 2 and 21, an erroneous insertion prevention piece fitting notch 58 is formed at the lower end of the front plate 52 and in a portion facing the erroneous insertion prevention piece fitting groove 43 of the lower case 1. ing. Also, the front plate 5
On both sides of the lower end of 2, there are stopper fitting notches 5 into which stoppers (not shown) provided in the magnetic tape cartridge holder of the recording/reproducing apparatus are fitted.
9 are formed respectively. As shown in FIGS. 22 and 23, a hook-shaped hanging portion 60 is provided at a side end of the upper plate 53 at a position facing the lock lever 47. As shown in FIGS. As shown in FIGS. 1 and 25, this hanging portion 60 passes through a hanging portion insertion hole 61 formed in the upper case 2 and extends toward the stopper portion 51 of the lock lever 47.

Next, the order of operation of the rotating lid 3 and the lock lever 47 will be explained. FIG. 18, FIG. 19, FIG. 25, and FIG. 27 are diagrams for explaining the state when the rotating lid 3 is closed. As described above, the opening of the release pin insertion hole 48 is covered by the pressing portion 50 of the lock lever 47 due to the pressing force of the leaf spring 63. As shown in FIG. 25, the stopper portion 51 is disposed in front of the hanging portion 60 of the rotating lid 3 in the rotational direction to prevent the hanging portion 60 from rotating. Therefore, due to the engagement between the stopper part 51 and the hanging part 60, the rotating lid 3 is held in a state where it will not open even if an external force is applied.

When a magnetic tape cartridge is inserted into a recording/reproducing device and lowered, the release pin 66 (see FIG. 19) is first inserted from the release pin insertion hole 48 and presses against the elasticity of the leaf spring 63. 50, thereby causing the lock lever 47 to rotate clockwise about the pivot pin 49 as shown by the arrow in FIG. With this rotation, the leaf spring 63
While being compressed, the stopper portion 51 descends toward the lower case 1 as shown in FIGS. 25 and 26. With this lowering, the stopper part 51 is moved to the hanging part 60.
The engagement with the lid 3 is released, the lid 3 is removed from the rotation path of the hanging portion 60, and the lid 3 becomes rotatable (openable).

Next, as shown in FIG. 27, the end plate 5 of the rotating lid 3 is
The lower end of the coil spring 6 is pushed up by the opening piece 67 to bias the rotary lid 3 in the direction of closing it.
The rotary lid 3 can be opened against the elasticity of the lid 5.
The open state of the rotating lid 3 is shown in broken lines in FIG. 27.

Note that flat parts 102 are formed at both left and right ends of the lower surface of the rotary lid 3 in order for the opening piece 67 to reliably push up and open the rotary lid 3.
2, a recessed hole 10 extending almost to the vicinity of the top plate 53 is provided in the center of the flat part 102 in order to prevent the end plate 54 constituting the flat part 102 from being warped or deformed due to shrinkage during molding.
1 is formed.

When closing and locking the rotary lid 3, the opening operation is completely opposite to the opening operation described above.
The rotating lid 3 is rotated in the closing direction by the restoring force of the coil spring 65. Next, the release pin comes out of the release pin insertion hole 48, and the restoring force of the leaf spring 63 pushes up the stopper part 51 forward in the rotating direction of the hanging part 60 and makes contact with the hanging part 60, while the pressing part 50 is released. The locking operation is completed by closing the opening of the pin insertion hole 48. Incidentally, it is preferable that the side surface 68 of the stopper part 51 that comes into contact with the hanging part 60 is sloped or rounded so that the stopper part 51 can easily enter the hanging part 60 forward in the rotational direction.

In this embodiment, the plate spring 63 is arranged on the back side of the stopper part 51, but the pressing part 50 and the upper case 2
A spring member such as a coil spring is interposed between the
The pressing portion 50 can also be elastically biased toward the release pin insertion hole 48 side.

As shown in Figures 2 and 4, the lower case 1
A circular through hole 69 is bored at a predetermined distance from the release pin insertion hole 48 on the front side. The release pin insertion hole 48 and the through hole 69 form a pair, allowing insertion of an auxiliary positioning pin (not shown) for mounting the magnetic tape cartridge in a predetermined position within the recording/reproducing apparatus. ing.

As shown in FIG. 4, bosses 14C and 14D for screw tightening are provided at both ends of the front surface of the lower case 1, and a similar boss portion 14E is located approximately in the center of the front surface in front of the joint between the front inner walls 7A and 7B. is installed protrudingly.

Hollow pins 70 are fitted onto the boss portions 14C and 14D, respectively, and also serve to support the hollow pins 70 used as tape guide members. hollow pin 7
A light source tube insertion hole 72 into which a light source tube 71 for detecting the start and end ends of the magnetic tape 5 is inserted is provided behind the magnetic tape 5 . Further, as shown in FIG. 30, the upper case 2 is provided with light source tube insertion recesses 73 at positions facing the light source tube insertion holes 72 of the lower case 1. Side wall 1 in lower case 1
A semicircular light-transmitting portion 75 is provided in a portion of the upper case 2 facing the light source tube insertion hole 72 and a portion of the side wall 74 of the upper case 2 facing the light source tube insertion recess 73, respectively. As shown in FIG. 2, a circular light-transmitting portion 75 is formed when the lower case 1 and the upper case 2 are joined.

When the magnetic tape cartridge is installed in a recording/reproducing apparatus, the light source tube 71 is inserted from the light source tube insertion hole 72 to the light source tube insertion recess 73, and a side surface of the magnetic tape cartridge is provided with a side surface facing the light source tube 71. A light receiving section 76 including a photodiode is arranged (see FIG. 4). The magnetic tape 5 extends in a direction crossing between the light source tube 71 and the light receiving section 76, and a transparent leader tape (not shown) made of polyester film is connected to the starting and ending ends of the magnetic tape 5. ing.

In FIG. 4, the starting end of the magnetic tape 5 is connected to the light source tube 71 inserted through the light source tube insertion hole 72 on the left side and the light receiving section 76, while the light source tube 71 inserted through the light source tube insertion hole 72 on the right side is connected to the light receiving section 76. The end of the magnetic tape 5 is detected at each of the points 76 and 76. That is,
The starting end of the magnetic tape 5 is determined by detecting the optical change from transmission to blocking of the radiation beam irradiated toward the leader tape and the magnetic tape 5 by using the light receiving section 76; Detection is performed by capturing an optical change from light blocking to light transmission using the light receiving section 76.

In order to detect the beginning and end of the magnetic tape 5 accurately and without noise by this optical means, this magnetic tape cartridge is designed as follows. The first is the sensor section (light source tube 71
The light receiving section 76) was divided into one for detecting the start end and the other for detecting the end, respectively. Second, in order to shorten the optical path distance from the light source tube 71 to the light receiving section 76 as much as possible, the light source tube insertion hole 72 is provided near the side wall 10. Thirdly, by leaving a part of the light source tube insertion hole 72 and the light source tube insertion recess 73 on the side facing the transparent part 75, and erecting a light shielding peripheral wall 77 in the other part, the emitted light is dispersed. Directivity was added to avoid this. Fourthly, in order to eliminate the influence of external light entering through the window 78 provided in the upper case 2 for detecting the amount of magnetic tape winding, the front inner walls 7A and 7B of the lower case 1 are
are extended continuously to near the side wall 10,
Furthermore, the front inner walls 79A and 79B of the upper case 2 are extended continuously to near the side wall 74 to block external light entering through the window 78 from reaching the light receiving section 76. A fifth pin-shaped first pin is provided between the hollow pin 70 serving as one of the guide members of the magnetic tape 5 and the reel 6 along the running direction of the magnetic tape.
Guide member 80 and roller-shaped second guide member 81
are sequentially provided, and the magnetic tape 5 is connected to the first guide member 80, the second guide member 81, and the hollow pin 70 (the third guide member 81).
The magnetic tape 5 is guided near the outer periphery of the light source tube insertion hole 72 and the light source tube insertion recess 73 by the middle second guide member 81, and the distance between the light source tube 71 and the magnetic tape 5 is adjusted. Made it as short as possible. Especially over relatively short distances, magnetic tape 5
By extending it in a meandering manner between the first guide member 80, the second guide member 81, and the hollow pin 70,
Light source tube insertion hole 72 when magnetic tape 5 is stationary
Sagging in the vicinity can be prevented, and the end of the magnetic tape 5 can be accurately detected at the same time as the magnetic tape 5 starts running.

In this embodiment, a pin-shaped first guide member 80 is used, a roller-shaped one is used as the second guide member 81, and a hollow pin 70 is used as the third guide member.
However, the shape of the guide member is appropriately selected depending on the tension applied when the magnetic tape 5 runs, and the key is to determine the arrangement of each guide member and how to hang the magnetic tape 5 between them. It has characteristics.

In the embodiment, the front inner walls 7A, 7 serve as light shielding members.
B, 79A, and 79B are provided in the lower case 1 and the upper case 2, respectively, but one of the cases may be provided with a front inner wall that extends close to the inner surface of the other case.

As shown in FIG. 4, the boss portion 14E of the lower case 1
Unlike the other boss portions 14A to 14D, the boss portion 14 is disposed between the reels 6 and has a relatively short distance from the reel 6. Therefore, lower case 1 and upper case 2
Synthetic resin shavings generated when the tapping screw 82 is screwed in to join the two may enter the inside of the cartridge case through the gap between the lower case 1 and upper case 2, and this shavings may enter the cartridge case. This damages the magnetic tape 5. In order to eliminate such problems, the front inner walls 7A and 7B are connected to the boss portion 1.
Continuously extend to the reel 6 side of 4E, boss part 14
E is provided in a chamber 83 defined by the front inner walls 7A, 7B and the front wall 9B, and is separated from the reel 6 side by the front inner walls 7A, 7B.

Reel 6 on the feeding side and reel 6 on the winding side
It is better to look at the difference in the amount of magnetic tape winding in magnetic tape 5.
As shown in FIGS. 29 and 30, both of the above are possible because the usage condition of the window 78 can be accurately grasped, the number of parts for the window 78 and the number of bonding processes to the case 2 can be reduced, and design requirements are required. A window 78 made of a relatively long transparent synthetic resin plate that spans the reel 6 is provided in the upper case 2. Conventionally, a window for viewing the amount of tape winding on the feed-out reel and a window for viewing the amount of tape winding on the take-up reel were provided separately, and a presser spring for holding the reel was installed on the inner surface of the upper case between the windows. However, if the number of windows 78 is reduced to one for the reasons mentioned above, it is necessary to change the installation position of the presser spring 84. Therefore, in this embodiment, a presser spring 84 is installed between the window 78 and the rear wall 85 of the upper case 2, as shown in FIG.

The presser spring 84 is used to press the reel 6 to the lower case 1 side when the magnetic tape cartridge is not in use, and is made of, for example, a stainless steel thin plate, and has a flat surface as shown in FIGS. 30 and 32. It has a substantially U-shape, and has a mounting base 86 in the middle, and two presser parts 87 extending from the mounting base 86 toward the reel 6 side. The presser part 87 has a flat part 8 that comes into contact with the tip of the central protrusion 38 of the reel 6.
8 is formed. As shown in FIG. 30, a recess 89 is formed on the inner surface of the upper case 2 facing the presser spring 84 in order to increase the permissible range of vertical movement of the presser spring 84.

FIGS. 34 and 35 are views showing modified examples of the presser spring 84, in which the planar shape of the presser spring 84 is approximately V-shaped.

As described above, since the presser spring 84 is installed between the window 78 and the rear wall 85 of the upper case 2, the central rear inner wall 8B for regulating the position of the reel 6 cannot be provided on the upper case 2 side. As mentioned above, it is provided on the lower case 1 side. Therefore, the rear wall 85 of the upper case 2, especially the central part, has poor impact resistance.
In addition, since the center part of the rear wall 85 is easily deformed when the upper case 2 is molded in a mold and taken out,
As shown in FIGS. 30 and 31, reinforcing ribs 90 are integrally formed inside the rear wall 85.

Further, reinforcing ribs 90 are integrally formed in each of the lower case 1 and the upper case 2 in order to increase the impact resistance of the boss portion 14E or the light-shielding peripheral wall 77, etc., and to prevent deformation when taking them out from the molding die. Furthermore, by providing the reinforcing ribs 90, the fluidity of the synthetic resin within the mold during molding is improved.

Next, the assembly order of the magnetic tape cartridge will be explained.

A feed-out reel 6 and a take-up reel 6 are installed in the lower case 1, and the magnetic tape 5 is stretched in a predetermined state. Then, the upper case 2 is placed on top of it (see FIG. 36), and the lower case 1 and the upper case 2 are joined with the tapping screws 82.

Separately from this, a winding portion 91 of the coil spring 65 for elastically biasing the rotating lid 3 in the closing direction is loosely fitted onto the first pivot pin 55 of the rotating lid 3. As shown in FIG. 38, the coil spring 65 has a winding part 91 in the middle, and the ends protruding from both sides of the coil spring 65 are horizontally extended to opposite sides, and both of their tips are bent downward. Ends 64A and 64B are formed. As described above, the winding portion 91 of the coil spring 65 is loosely fitted into the first pivot pin 55, and one bent end 64A is attached to the top plate 5 of the rotating lid 3.
3 into the locking hole 92A provided at the end of the coil spring 65, and lift the other bent end 64B upward against the elasticity of the coil spring 65.

In this state, as shown in FIG. 37, the first pivot pin 55 of the rotating lid 3 is fitted into the support hole 57 provided in the side wall 74 of the upper case 2, and the other bent end 64B of the coil spring 65 is pushed upward. Locking hole 92B provided on the top surface of case 1 (Fig. 29, 3
(See Figure 8).

Next, the second pivot pin 56 is fitted into the other support hole 57 provided in the side wall 74 of the upper case 2 while slightly bending the rotating lid 3 . This second
In order to facilitate insertion of the pivot pin 56, the rotating lid 3
can be made from acrylonitrile-based synthetic resins such as acrylonitrile-butadiene-styrene copolymer resin (AS resin) and acrylonitrile-butadiene-styrene copolymer resin (ABS resin) to give it flexibility. As shown in FIGS. 39 and 40, the support hole 5 is inserted from the edge of the side wall 73 in the upper case 2.
A fitting guide groove 93 can be provided toward 7. As shown in FIG. 40, the fitting guide groove 93 has an inclined bottom so that the end edge side of the side wall 73 is deeper than the support hole 57 side.

By fitting this second pivot pin 56 into the support hole 57, the hanging portion 6 protruding from the rotating lid 3
0 is the hanging part insertion hole 6 provided in the upper case 2
It is inserted into the cartridge case from 1. In this way, the rotating lid 3 is rotatably supported by the upper case 2, and the elastic force of the coil spring 65 biases the rotating lid 3 in the closing direction, completing the assembly of the magnetic tape cartridge. do. In addition, in order to securely hold the coil spring 65 installed from the rotating lid 3 to the upper case 2 in a predetermined position without protruding from the upper surface of the rotating lid 3 or the upper case 2, a coil spring 65 is installed near each locking hole 92A, 92B. is the accommodation groove 94
are provided for each. Pivot pins 55, 56
Since there is no protrusion on the outer peripheral surface of the case, after joining the lower case 1 and the upper case 2 as described above,
They can be respectively fitted into the support holes 57 of the cartridge case.

When the magnetic tape cartridge is not in use, as shown in FIG. The magnetic tape 5 is supported in a slightly raised state, which helps prevent the magnetic tape 5 from sagging. When the magnetic tape cartridge is installed in a recording/reproducing device, the drive shaft inserted into the drive shaft insertion recess 40 of the reel 6 allows
The reel 6 is lifted slightly upward against the elasticity of the presser spring 84, and as a result, the magnetic tape 5
Since the magnetic tape 5 also moves upward, the lower end of the magnetic tape 5 separates from the raised portion 44. When the magnetic tape 5 runs along the front surface of the cartridge case, there is a tendency for the magnetic tape 5 to move up and down significantly, especially at the center. By suppressing shaking, stable tape running is possible, and damage to the edges of the magnetic tape due to shaking can be reduced.

As explained above, according to the present invention, by configuring the reel rotation stopper with the bent part of the rotation stopper facing the reference pin insertion hole, there is no need to specially drill a release pin insertion hole. Moreover, the shape of the rotation stopper member can be simplified, and when the reference pin rotates the rotation stopper member, the rotation stopper member can be smoothly and reliably engaged with the reference pin. It is possible to provide a magnetic tape cartridge that is suitable for miniaturization and that can reliably release the reel from rotating, except for its drawbacks.

[Brief explanation of the drawing]

1 to 40 are diagrams for explaining a magnetic tape cartridge according to an embodiment of the present invention. Figures 1 and 2 are a top view and bottom view of the magnetic tape cartridge, Figure 3 is a front view of the magnetic tape cartridge with the rotating lid removed, and Figure 4 shows one reel in place. Figure 5 and Figure 6 are a front view and bottom view of the lower case, Figure 7 is a sectional view taken along the line shown in Figure 4, and Figure 8 is an exploded perspective view of the reel rotation stopper. 9 is a partial sectional view of the reel rotation stopper, FIG. 10 is a perspective view of the left rotation stopper member, FIG. 11 is an exploded front view with a part of the reel in cross section, FIG. Fig. 13 is a plan view and bottom view of the lower flange of the reel, Fig. 14 is an enlarged cross-sectional view of the main part to explain the fitted state of the tape stopper on the reel, and Fig. 15 shows that the reel is stopped from rotating. FIG. 16 is an enlarged plan view of the rotation stop device in a state in which the reel rotation stop is released, and FIG.
18 is an enlarged plan view of the main parts showing the installed state of the lock lever, FIG. 19 is a sectional view taken along the line of FIG. 18, FIG. 20 is a perspective view of the lock lever, and FIGS. Figure 22 is a front view and plan view of the rotating lid, Figure 23 is Figure 22-
24 is a cross-sectional view along the line of FIG. 22, FIG. 25 is an enlarged sectional view of the main part showing the state in which the rotating lid is closed, and FIG. 26 is the state in which the rotating lid is open. FIG. 27 is a side view of the magnetic tape cartridge for explaining the state in which the rotary lid is opened; FIG. 28 is a sectional view taken along the line of FIG. 4; FIGS. 29 and 30. 31 is a sectional view along the line of FIG. 30, FIGS. 32 and 33 are a plan view and side view of the presser spring, and FIGS. 34 and 35 are the presser spring. A plan view and a side view showing a modified example of
6 and 37 are a side view and a plan view for explaining the assembled state of the magnetic tape cartridge,
Fig. 38 is an enlarged cross-sectional view of the main part showing the state of engagement with the cartridge case rotating lid, Fig. 39 is an enlarged side view of the vicinity of the support hole in the upper case, and Fig. 40 is the third
FIG. 9 is a sectional view taken along the line, and FIG. 41 is a plan view of a conventional magnetic tape with the upper case removed. 1... Lower case, 6... Reel, 10... Side wall, 15A, 15B... Pivot, 16A, 16B...
...Reference pin insertion hole, 18A, 18B... Rotation stopper member, 19A, 19B... Sleeve, 20A, 2
0B... Receiving part, 21A, 21B... Claw part, 22
A, 22B...bent part, 23A, 23B...slanted part, 24B...spring member, 25... annular part, 26
A, 26B... elastic contact end, 28... lower flange,
30...Tooth groove, 42...Reference pin.

Claims (1)

[Scope of utility model registration request] Rotatably supported within the cartridge case,
A rotation stopper member having a claw portion at its tip, a reel having a large number of tooth grooves on its outer periphery, and a spring member that elastically biases the claw portion of the rotation stopper member in a direction to fit into the tooth grooves of the reel. In the magnetic tape cartridge, the rotation stopper member is rotated against the elasticity of the spring member to separate the claw portion from the tooth groove and release the engagement between the rotation stopper member and the reel. A substantially dogleg-shaped bent portion is formed between the rotation support portion and the claw portion of the rotation stopper member, and the bent portion is made to face the reference pin insertion hole drilled in the cartridge case. The engagement between the claw portion of the rotation stopper member and the tooth groove of the reel is released by contact between the bent portion and the pointed end of the reference pin inserted into the cartridge case through the pin insertion hole. A magnetic tape cartridge characterized by comprising: