JPH09161439A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely lock a reel with a locking means for reel. SOLUTION: Engagement parts 40 and 41 for locking are supported on the side of a slide drum part 22 so that they can rotate. Cam followers 44 and 45 of the engagement parts 40 and 41 for locking are in contact with cam surfaces 32 and 33 of the slide drum part 22. When no video tape cassettes are loaded in a video cassette, engagement nibs 42 and 43 are engaged to gears 18 and 19 of reels 12 and 13 while the cam followers 44 and 45 are guided to the cam surfaces 32 and 33 if the slide drum part 22 is located in front of the cassette and the cam followers 44 and 45 are guided to the cam surfaces 32 and 33 and the engagement nibs are separated from the gear of the reel if the slide drum part 22 is located behind the cassette.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cassette suitable for application to a video tape cassette and the like.
More specifically, the present invention relates to a magnetic tape cassette that enables a reel to be reliably locked by a reel locking means.

[0002]

2. Description of the Related Art A conventional magnetic tape cassette, for example, FIG.
Video tape cassette 5 whose internal structure is shown in
Is a pair of reels 52, 53 rotatably arranged in a cassette half 51 (the figure shows a state in which reels and the like are accommodated in the lower cassette half with the upper cassette half removed). Magnetic tape 5 on 52 and 53
4 is wound (wrapped). The magnetic tape 54 is guided by tape guides 55 and 56 on the front side of the cassette (upper side in FIG. 6) and on both left and right sides, and passes through the opening 57 on the front side of the cassette half 51. Teeth 60 and 61 are formed around the entire circumference of the lower flanges 58 and 59 of the reels 52 and 53.

On the other hand, in order to prevent the magnetic tape 54 from loosening during storage or handling of the cassette when the video tape cassette 5 is not loaded in the video deck (not shown), it is on the rear side of the cassette and on the reel. 52, 53
A lock member 62, which is a reel locking unit that locks the rotation of the reels 52 and 53, is arranged in a space formed between the spaces, which can be said to be a substantially triangular shape (see, for example, JP-A-7-14342).

The conventional lock member 62 is provided with substantially triangular ribs 80 and 81 located between the rear plate portion 63 of the cassette half 51 and the reels 52 and 53. Rib 8
The linear portions 65 and 66 of the cassettes 0 and 81 in the front-rear direction of the cassette are arranged in parallel and face each other, and the locking member 67 is provided between the linear portions 65 and 66.
Are slidably inserted. The locking member 67 is biased toward the front side of the cassette by a compression spring 68 arranged between the locking member 67 and the rear plate 63. Then, this locking member 67
An insertion hole 69 for inserting the unlocking pin of the video deck is provided on the bottom surface of the. The bottom wall 70 of the cassette half 51 is provided with an opening (not shown) corresponding to the insertion hole 69 of the locking member 67.

The locking member 67 is made of, for example, a resin having appropriate elasticity, and as shown in FIG. 7, a rectangular sliding body portion 71 having a relatively wide bottom area for stable sliding.
Is provided. Further, locking claws 72, 73 capable of locking the teeth 60, 61 of the reels 52, 53 are integrally formed on the front end surface of the slide body 71. The locking claws 72, 73 are formed relatively long and slender, and the locking claws 72, 73 are formed.
Thin hinges 74 and 75 are provided at the root (portion connected to the slide body). As a result, the locking claw 7
2, 73 can be elastically displaced laterally.
Then, as shown in FIG. 7, a suitable guide means such as a pin 90 is provided on the cassette half 51 so as to project therefrom.
With 0, as the slide body 71 moves forward in the front of the cassette, the locking claws 72 and 73 open so as to bite into between the teeth 60 and 61, so that the reels 52 and 53 are securely locked and the rear of the cassette is locked. By retracting to tooth 6
The lock release is ensured by performing the closing operation so as to reduce the distance between the locking claws so as to be separated from 0 and 61.

On the other hand, separately from this, as shown in FIG. 8, the pair of engaging portions 200, 200 and the slide body 202 are separately provided, and the slide body 202 is used as the compression spring 2.
At 07, the cassette is urged forward (upward in FIG. 8), both engaging portions 200 are rotatably attached to a pair of shafts 204, 204 projecting from the bottom surface of the lower cassette half 203.
The ends of the arms 216 of the two engaging portions 200 can be fitted into the fitting grooves 215 formed on both side surfaces of the slide body so that the two locking claws 217 can be engaged with the teeth 210 and 211 of the two reels 205 and 206. There is also a video tape cassette 8 configured as described above (see Japanese Patent Laid-Open No. 5-174536).

In this case, when the video tape cassette 8 is not loaded in the VCR, the slide body 202 is urged by the compression spring 207 to the forward movement limit position, and each of the engaging portions 200 is moved. Locking claw 217
Engages the teeth 210, 211 of the reels 205, 206,
The reels 205 and 206 are locked. On the other hand, when the video tape cassette 8 is loaded into the VCR,
The lock releasing means is inserted from the lower side of the cassette, and the slide barrel 202 is retracted rearward of the cassette (downward in FIG. 8). As a result, the left engaging portion 200 in FIG. 8 is clockwise and the right engaging portion in FIG. The engaging portion 200 rotates counterclockwise, the both locking claws 217 are pulled out from between the teeth 210 and 211, and the reel is unlocked.

[0008]

However, in the former video tape cassette 5, the locking claws 72, 73 of the locking portion 67 of the lock device 62 are elastically displaceable laterally, so that the locking claws 72, 73 is elongated and the locking claw 7
Since the hinges 74 and 75 are provided by thinning the bases of the reference numerals 2 and 73, the hinges 74 and 75 are dented when the video tape cassette 5 is dropped on the floor or stored for a long period of time, and the locking claws are provided. 72, 73 may be broken from the hinges 74, 75 or may be plastically deformed to cause the reels 52, 5
There was a risk that the lock of No. 3 would become uncertain.

On the other hand, the latter video tape cassette 8 has the following problems. In the engaging structure of the arms 216 of the both engaging portions 200 and the fitting grooves 215,
In order to reliably lock and unlock the reel, it is desirable to set a large amount of movement of the tip of the engaging claw 217. For that purpose, the length of the engaging claw 217 (the radius of rotation from the shaft) is set. This can be achieved by setting the arm 216 large or, on the contrary, short arm 216. However, lengthening the engaging claw 217 is greatly restricted by the limitation of the installation space, which is a big problem particularly in a compact cassette case, and shortening the arm 216 reduces the turning radius. , The groove 215 has a relatively deep groove depth as compared with the width of the slide body (the width in the direction orthogonal to the sliding direction) in order to allow a deviation between the pivotal movement of the arm 216 and the linear movement of the slide body 202. Not only does it require
This is not preferable because it restricts the sliding amount of 2 or greatly restricts the engagement structure with the slide body 202 (fitting structure between the arm 216 and the fitting groove 215).

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, and it is possible to prevent the engagement claw from sagging and reduce the size thereof, and moreover, to reliably lock the reel. It provides a cassette.

[0011]

The above object of the present invention is to provide a reel in which a pair of reels are rotatably mounted by winding a magnetic tape in a cassette half and engage with the teeth of a flange of the reel. In a magnetic tape cassette having reel locking means for preventing rotation, the reel locking means is arranged such that its slide barrel is slidable in the cassette front-rear direction between the pair of reels. Urging means for urging the portion in the cassette front-rear direction is provided,
Tooth provided on both sides of the slide body facing the reel, having cam surfaces recessed in a direction substantially perpendicular to the front-back sliding direction of the slide body, and provided around the entire circumference of the flange periphery of the reel. Lock engaging portions each having an engaging claw engageable with and a cam follower guided by contacting with the cam surface are rotatably arranged on both sides of the slide body. The lock follower is rotated by the rotation of the cam follower along with the movement of the portion in the cassette front-rear direction to engage or disengage the engagement claw and the tooth. It can be achieved by a magnetic tape cassette characterized in that

In a preferred embodiment of the present invention, the cam surface has a locking surface for holding the cam follower so as to maintain the engagement between the engaging claw and the tooth, at a rear end of the cassette, In addition, the depth of the recess can be gradually reduced toward the front side of the cassette. In still another embodiment, the lock engaging portion includes a biasing piece that abuts against the inner wall of the cassette so that the engaging claw is biased in the direction of engaging the tooth. You can

In the present invention, when the magnetic tape cassette is not loaded in the cassette deck, the slide barrel is urged to the forward movement limit position by the urging means. Then, the cam follower of the locking engagement portion rotatably arranged on the cassette half is guided forward by the cam surface of the slide barrel portion, and the locking engagement portion rotates toward the reel side, so that the locking engagement is performed. The engaging claws of the section are engaged with the teeth of the flange of the reel. This ensures that the reel is locked.

When the magnetic tape cassette is loaded in the cassette deck, the slide body is pushed back by the lock release pin of the cassette deck, and the cam follower of the lock engaging portion is guided to the cam surface of the slide body. To move backwards. As a result, the locking engaging portion rotates, the engaging claw is pulled out from the tooth of the flange of the reel, and the reel is unlocked.

In this case, since the locking engagement portion rotates and the engagement claw engages with the reel, it is not necessary to elastically deform the engagement claw, and the engagement claw is made thick to prevent sagging. can do. Further, the engagement position between the cam follower of the locking engagement portion and the cam surface of the slide barrel portion is configured to be appropriately displaced along the sliding direction of the slide barrel portion, so that the amount of slide and the amount of rotation are A large difference can be tolerated, and the required amount of movement of the engaging claw can be secured even if the positions of the slide body and the locking engaging portion are brought close to each other.

Further, when the locking engagement portion is provided with a biasing piece for rotating the engagement claw toward the tooth side of the reel, a separate spring for biasing the locking engagement portion is unnecessary. Therefore, it is preferable.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment in which the magnetic tape cassette according to the present invention is applied to a video tape cassette will be described in detail with reference to FIGS. FIG. 1 is an enlarged plan view showing a lock portion for a reel of a video tape cassette to which a magnetic tape cassette according to the present invention is applied, FIG. 2 is a perspective view of a slide body portion, and FIG. 3 is AA of FIG. 5 is a sectional view, FIG. 4 is a sectional view taken along line BB in FIG.
[Fig. 3] is a perspective view showing only a pair of locking engaging portions.

As shown in FIG. 1, in the video tape cassette 1 according to this embodiment, a pair of reels 12 and 13 are rotatable inside a lower cassette half 11 (the figure shows a state in which an upper upper cassette half is removed). Placed on reel 12,
A magnetic tape (not shown) is wound around 13. Teeth 18 and 19 are formed around the entire circumference of the lower flanges 14 and 15 of the reels 12 and 13.

On the other hand, in order to prevent the magnetic tape from slackening when the video tape cassette 1 is not loaded in the video deck (not shown), it is located between the reels 12 and 13 and at the rear of the cassette (lower side in FIG. 1). A lock device 21 that is a reel lock unit that locks the reels 12 and 13 is arranged in a substantially triangular space 20 formed on the side). The operation of each part other than the lock device 21 is as shown in FIG.
The video tape cassette 5 is the same as the conventional video tape cassette 5 described above, and its description is omitted here to avoid redundant description.

Now, the lock device 21 includes the reels 12, 1
3 and a slidable body 22 that is slender (a width in the left-right direction of the cassette is narrow) so that it can slide between reels;
Compression spring 23 which is a biasing means for biasing to the 13 side.
And the lock engaging portions 40 and 41 arranged on the side of the slide body portion 22.

As shown in FIG. 2, the slide barrel portion 22 is provided with a hollow release pin insertion portion 24 and a guide portion 25 on the rear side thereof. Release pin insertion part 24
Is formed in a relatively deep dome shape as shown in FIG.
An inclined surface 27 is provided at the rear end of the opening 26 at the lower end. Further, the outer width of the release pin insertion portion 24 is the reel 1
It is relatively narrow so that it can be inserted between 2 and 13 sufficiently.

As will be described later, when the video tape cassette 1 is mounted on the VCR, a lock releasing pin (not shown) of the VCR presses the inclined surface 27 so that the slide body 22 is retracted. The reels 12 and 13 are unlocked. The unlocking pin inserting portion 24 contacts the inner surface of the front end wall of the opening 26 when the slide barrel 22 is retracted by a predetermined distance, that is, until the reels 12 and 13 are unlocked as described later. It is formed with a length in the front-rear direction so as not to contact with each other. At the center of the front end wall of the opening 26, the guide groove 2 having a predetermined width is provided.
8 are provided.

As shown in FIG. 2, a U-shaped groove 29 for accommodating one end of the compression spring 23 is provided above the guide portion 25.
Is provided, and the protruding rib 3 is provided in the U-shaped groove 29 over the entire circumference.
0 is provided. A locking groove 31 for locking one end of the compression spring 23 is provided behind the protruding rib 30. On both side surfaces of the guide portion 25, both locking engagement portions 4 are provided.
Cam surfaces 32, 33 for rotating 0, 41 are provided. As shown in FIG. 1, the cam surfaces 32, 33 have a shape in which the depth gradually inwards from the front (upper side in FIG. 1) to the rear of the slide body 22 (shape gradually deeper). Has become. Also, the cam surface 32,
33 is a locking surface 3 that holds the cam followers 44 and 45 so as to maintain the engagement between the engaging claws 42 and 43 and the teeth 18 and 19.
2a and 33a are provided at the rear end of the cassette.

The lower end surface of the guide portion 25 is provided with guide grooves 34 and 35 located at both end portions as shown in FIG. The guide grooves 34, 35 are fitted into the guide rails 36, 37 of the cassette half 11, and by this, the slide body 22 is restricted so as to linearly slide only in the front-rear direction. As shown in FIGS. 1 and 5, the locking engagement portions 40 and 41 are formed on the boss portion 4.
Hook-shaped engaging claws 42 and 43 which have teeth 6 and 47 and which can be engaged with the teeth 18 and 19 of the reels 12 and 13, and the slide body 22.
Cam followers 44, 45 that follow the cam surfaces 32, 33 of the
Are provided on the boss portions 46 and 47. The bosses 46, 47 are attached to the support shafts 48, 49 of the cassette half 11.
Is rotatably supported. In the present embodiment, the urging pieces 110 and 111 for urging the locking engaging portions 40 and 41 to rotate toward the engaging side further include the boss portions 46 and 47.
Are provided integrally. This biasing piece 110, 111
Is attached by being pressed against the ribs 112 and 113 of the lower cassette half 11 and elastically deformed,
The elastic restoring force urges the locking engagement portions 40 and 41 to rotate.

As shown in FIG. 1, the lower cassette half 11
Is provided with a prismatic stopper 114 for restricting the forward movement of the slide barrel portion 22. Slide body 2
The cam followers 44 and 45 of the lock engaging portions 40 and 41 are guided by the cam surfaces 32 and 33 of the slide body portion 22 and are arranged at the forward movement limit position in a state where 2 is in contact with the stopper 114. . Then, the locking engaging portions 40, 4
1 rotates on the engagement side, that is, the locking engagement portion 40 on the left side in the figure rotates counterclockwise, and the locking engagement portion 41 on the right side rotates clockwise, so that the engagement claws 42 and 43 are reeled. 1
It is inserted between the teeth 18 and 19 of 2 and 13 by a predetermined size or more.
The reels 12 and 13 are securely locked by being held by a and 33a.

On the rear side of the stopper 114, there is provided a guide projection 115 extending linearly in the front-rear direction of the cassette and connected to the stopper. In this guide projection 115,
A guide groove 28 provided in the release pin insertion portion 24 of the slide body portion 22 is inserted. As a result, the tip of the release pin insertion portion 24 moves linearly. Further, on the rear side of the guide protrusion 115, a pin insertion hole 116 for inserting the lock release pin of the video deck is provided in correspondence with the release pin insertion portion 24 of the slide barrel portion 22.

Next, the operation of the lock device 21 will be described with reference to FIG. When the video tape cassette 1 is taken out from the VCR,
Since the lock release pin of the video deck is not inserted into the release pin insertion portion 24 of the slide body 22, the slide body 22 is pressed against the stopper 114 by the urging force of the compression spring 23.

At this time, as described above, the cam followers 44, 45 of the locking engaging portions 40, 41 are guided to the cam surfaces 32, 33 of the slide barrel portion 22 and are arranged at the front movement limit position. As a result, the lock engaging portion 4
0 and 41 rotate counterclockwise and clockwise, respectively, and the engaging claws 42 and 43 are inserted between the teeth 18 and 19 of the reels 12 and 13, so that the reels 12 and 13 are securely locked. Therefore, the magnetic tape can be prevented from loosening, and when the video tape cassette 1 is loaded into the VCR,
The magnetic tape can be prevented from being entangled with the guide rollers of the VCR.

On the other hand, when the video tape cassette 1 is loaded in the video deck, the lock release pin of the video deck is inserted into the opening 26 of the release pin insertion portion 24 from the pin insertion hole 116 of the cassette half 11. Then, the lock release pin presses the inclined surface 27 (FIG. 3),
The slide body 22 is retracted by a predetermined distance against the urging force of the compression spring 23, and the cam followers 44, 45 of the locking engaging portions 40, 41 are moved by the slide body as shown by the two-dot chain line in FIG. The cam surfaces 32 and 33 of the guide 22 are arranged at the backward movement limit position. With this, the lock engaging portion 4
0 and 41 rotate to the non-engagement side, the engaging claws 42 and 43 are completely extracted from between the teeth 18 and 19 of the reels 12 and 13, and the reels 12 and 13 are unlocked so that they can rotate. Become.

As described above, the video tape cassette 1 has the cam surfaces 32, 33 formed by the movement of the slide barrel portion 22.
Movement of the cam followers 44, 45 guides the locking engagement portions 40, 41 to rotate.
3 is engaged or disengaged with the teeth 18, 19 of the reels 12, 13. The pair of locking engagement portions 40 and 41 used in the present invention are, as shown in FIG. 5, the vertical center of the rotating shaft, which is orthogonal to the rotating shaft (center axis of the bosses 46 and 47). With a shape that is vertically symmetric with respect to the plane, the pair of locking engaging portions can be created with only one mold.

In the present invention, the shapes of the slide body portion and the locking engagement portion, the shape of the cam surface, the shape of the cam follower, etc. are not limited to those in the above-mentioned embodiment, but may be changed as necessary. It can be changed as appropriate.

[0032]

As described above, according to the magnetic tape cassette of the present invention, the cam follower of the lock engaging portion is guided to the cam surface provided on the side surface of the slide barrel portion as the slide barrel portion advances, and the lock engaging portion is locked. The engaging portion rotates and the engaging claws of the locking engaging portion are engaged with the teeth of the reel.

Therefore, according to the magnetic tape cassette of the present invention, since it is not necessary to elastically deform the engaging claws as in the conventional case, the engaging claws can be made thick to prevent settling, and the reels The lock can be reliably performed. Further, the engagement position between the cam follower of the locking engagement portion and the cam surface of the slide barrel portion is configured to be appropriately displaced along the sliding direction of the slide barrel portion, so that the amount of slide and the amount of rotation are A large difference can be tolerated, and even if the positions of the slide barrel portion and the lock engaging portion are brought close to each other, the necessary movement amount of the engaging claw can be secured, and a small tape cassette can be obtained. It is suitable to apply.

Further, in the structure in which the locking engaging portion is provided with the biasing piece for rotating the engaging claw toward the tooth side of the reel, the spring for biasing the locking engaging portion is unnecessary. It is possible to reduce the number of parts.

[Brief description of the drawings]

FIG. 1 is an enlarged plan view showing a reel lock portion of a video tape cassette to which a magnetic tape cassette according to the present invention is applied.

FIG. 2 is a perspective view of a slide body portion shown in FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 1;

FIG. 5 is a perspective view showing only a pair of locking engaging portions.

FIG. 6 is a configuration diagram of a conventional video tape cassette.

FIG. 7 is a plan view of a conventional lock member.

FIG. 8 is an enlarged configuration diagram of a lock member portion of a conventional video tape cassette.

[Explanation of symbols]

 1 Video Tape Cassette 11 Cassette Half 12, 13 Reel 18, 19 Teeth 21 Locking Device 22 Slide Body 23 Compression Spring 32, 33 Cam Surface 40, 41 Locking Engagement 42, 43 Engaging Claws 44, 45 Cam Follower

Claims (3)

[Claims] 1. A cassette half is provided with a pair of reels rotatably mounted by winding a magnetic tape and engaging with teeth of a flange of the reel to prevent reel rotation. In the magnetic tape cassette, the reel locking means is arranged such that its slide barrel is slidable in the cassette front-rear direction between the pair of reels, and is biased to bias the slide barrel in the cassette front-rear direction. Means are provided, having cam surfaces recessed in a direction substantially orthogonal to the front-back sliding direction of the slide body on both side surfaces of the slide body facing the reel, and the entire circumference of the flange peripheral edge of the reel. Locking engaging portions each having an engaging claw that is engageable with teeth and a cam follower that is guided by contacting with the cam surface are rotatably arranged on both sides of the slide body. The lock engagement portion is rotated by the rotation of the cam follower accompanying the movement of the slide barrel portion in the front-rear direction of the cassette, so that the engagement claw and the tooth are engaged or disengaged. A magnetic tape cassette characterized by being configured to perform. 2. The cam surface has a locking surface for holding the cam follower so as to maintain the engagement between the engaging claw and the tooth at the rear end of the cassette, and has a recess depth at the front of the cassette. The magnetic tape cassette according to claim 1, wherein the magnetic tape cassette is configured to be gradually shallowed toward the side. 3. The lock engagement portion includes a biasing piece that abuts against the inner wall of the cassette so that the engagement claw is biased in a direction in which the tooth engages with the tooth. Or 2
The magnetic tape cassette described in.