JP3144310B2 - Reel stand braking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reel stand brake system for a video tape recorder, a digital audio tape recorder or the like, and more particularly to a highly reliable reel stand brake system which has a simple structure and prevents damage to a magnetic tape. Is provided.

[0002]

2. Description of the Related Art FIG. 5 is a plan view showing a schematic configuration of a conventional reel stand braking device used in a video tape recorder (hereinafter, referred to as a VTR). FIG. 6 shows a state when a cassette is mounted, that is, a magnetic tape loading operation is started. FIG. 7 is a plan view of the part at the time, FIG. 7 is a plan view of the part showing a fast-forward or rewind operation, and FIG. 8 is a plan view of the part showing a stop operation for stopping the fast-forward or rewind operation.

First, the overall configuration will be described. The capstan motor 1 includes a take-up reel base 4 and a supply-side reel base 3.
It is a driving source of. Both ends of the magnetic tape 5 are wound around two reels provided on the tape cassette 2. When the tape cassette 2 is mounted on the VTR, the magnetic tape 5 is pulled out by a mechanism (not shown),
And the loading is completed. The magnetic tape 5 is sandwiched between the capstan shaft 7 and the pinch roller 8 at the time of reproduction or reverse reproduction, and travels with the pinch roller 8 separated from the capstan shaft 7 at the time of rewinding or fast-forwarding.

Next, brake means for braking the rotation of the reel base 4 in a conventional reel base braking device will be described with reference to FIGS. 6, 7 and 8. FIG. A first brake arm 10 is rotatably mounted around a first support shaft 9 fixed to the base. In the rotation range of the first brake arm 10, the first brake arm 10 can freely contact the outer diameter portion of the reel base 4, and the contact part of the first brake arm 10 with the reel base 4 has a frictional force corresponding to the pressing force. The first brake shoe 11 is attached in order to stably generate.

The first brake arm 10 has one end of a first tension coil spring 12 serving as an elastic member suspended therefrom.
The other end of the first tension coil spring 12 is fixed to the base 13. In the first brake arm 10, a turning moment always acts in the direction A due to the reaction force of the first tension coil spring 12, and the first brake shoe due to the reaction force at the position where it contacts the reel base 4. A substantially constant frictional force is applied between the reel 11 and the reel base 4 to apply a braking force to the reel base 4.

A first guide pin 14 is formed integrally with the first brake arm 10. When a braking force to the reel base 4 is unnecessary, the first guide pin 14 is provided by a guide means (not shown).
The drive plate 15 is moved in the direction B, contacts the first guide pin 14 of the first brake arm 10, and changes the rotation position of the first brake arm 10 until the first brake shoe 11 and the reel base 4 are separated. By regulating, the reel base 4
The braking force has been released.

Further, a second support shaft 16 fixed to the base 13 is provided.
The second brake arm 17 is rotatably mounted around the rotation center. In the rotation range of the second brake arm 17, the second brake arm 17 can freely come into contact with the rotating outer diameter portion of the reel base 4, and the contact part of the second brake arm 17 with the reel base 4 has a frictional force corresponding to the pressing force. The second brake shoe 18 is stuck to stably generate the torque.

The second brake arm 17 has one end of a second tension coil spring 19 serving as an elastic member suspended therefrom.
The other end of the second tension coil spring 19 is fixed to the base 13 or the like. In the second brake arm 17, the second
A turning moment always acts in the C direction due to the reaction force of the tension coil spring 19, and a substantially constant rotation force is generated between the second brake shoe 18 and the reel table 4 due to the reaction force at a position where the tension coil spring 19 contacts the reel table 4. The frictional force is applied to apply a braking force to the reel base 4.

In the direction of rotation of the magnetic tape 5 to be sent out of the reel base 4, that is, in the direction of arrow H, the second brake shoe 18 is attached to the rotation support shaft.
The vicinity of the contact portion of the brake arm 17 with the reel base 4 is elastically deformed in the direction D after the contact, and the second tension coil spring 1
In addition to the reaction force of No. 9, a restoring force due to the deformation of the second brake arm 17 in the direction D is added, and the brake becomes a self-penetrating brake, and a large braking force is obtained. On the contrary, the reel base 4
In the take-up rotation direction of the magnetic tape 5, the second brake arm 17 does not elastically deform, so that a braking force smaller than the braking force in the rotation rotation direction of the magnetic tape 5 of the reel base 4 can be obtained. Has become.

A second guide pin 20 is formed integrally with the second brake arm 17, and when a braking force to the reel base 4 is not required, the second guide pin 20 is provided by a guide means (not shown).
The drive plate 21 is moved in the direction E, the second guide pin 20 of the second brake arm 17 and the second drive plate 21 abut,
The braking force of the second brake arm 17 is released by restricting the rotational position of the second brake arm 17 until the second brake shoe 18 and the reel base 4 are separated from each other.

The detailed operation of the conventional reel stand braking device configured as described above will be described with reference to the drawings.

First, in the tape cassette 2, when the cassette is mounted on the reel bases 3 and 4 while releasing the brake in the cassette provided so that the magnetic tape 5 does not slack, the brake in the cassette when the cassette mounting is completed is described. Is suddenly released, the unwound magnetic tape 5 deviates outside the tape cassette 2 and largely slackens, and the magnetic tape 5 falls from the height regulating member. In order to prevent tape damage, the first guide pin 14 of the first brake arm 10 is separated from the first drive plate 15 by a drive means (not shown) during the cassette mounting operation, so that the reel is driven as described above. The first brake shoe 11 abuts on the base 4 to apply a braking force. For this reason, when the cassette is completely mounted, the braking force is applied to the reel base 4, so that the magnetic tape 5 does not slack.

Next, when the loading operation is performed after the cassette is completely mounted, the tape pull-out member is driven by the driving means (not shown), the magnetic tape 5 is pulled out and wound around the cylinder 6, and the reproduction / recording traveling is stabilized. The operation of pulling out the magnetic tape 5 is continued until it is positioned so that it can be performed. At this time, if the braking force is not applied to the reel base 4, the tension of the magnetic tape 5 pulled out becomes very small.
When the magnetic tape 5 contacts the cylinder 6, the magnetic tape 5
Is dropped from the regulating lead surface of the cylinder 6, the magnetic tape 5 sags when the drawing speed of the magnetic tape 5 is changed during the loading operation, the magnetic tape 5 drops from the height regulating member, or the magnetic force is sent out near the completion of the loading operation. The magnetic tape 5 was excessively protruded due to the inertia of the rotation of the reel base 4 by the tape 5, and the magnetic tape 5 was largely slack and deviated from the traveling path, so that the magnetic tape 5 was damaged, that is, tape damage occurred.

For this reason, during the loading operation from the time of loading the cassette to the completion of loading as in the case of loading the cassette, the first driving plate 1 is moved in the same manner as in the above-described cassette mounting operation.
5 is separated from the first guide pin 14 of the first brake arm 10, and the first brake arm 10 is moved to the first position by the rotation moment balanced with the reaction force of the first tension coil spring 12.
The first brake shoe 11 of the brake arm 10 is brought into contact with the reel base 4, a braking load is applied to the reel base 4, and a predetermined tension is applied to the magnetic tape 5 to be pulled out. When the magnetic tape 5 is dropped from the height regulating member or when the reel base 4 rotates due to inertia of the reel base 4, the magnetic tape 5 comes out from the regulating lead surface at the time of contact with the magnetic tape 6. Prevents sagging due to too much.

Referring to FIGS. 7 and 8, braking means for stopping the magnetic tape 5 from fast forward or rewind at high speed will be described. First, as a fast-forward or rewind operation at high speed, the reel base on the winding side must be driven to rotate at high speed. At this time, since the winding load on the driven reel unit must be minimized, the braking force is normally released from the driven reel unit. That is,
The first driving plate 15 is in the direction of arrow B, and the second driving plate 21 is in the direction of arrow E.
The first brake arm 10 and the second brake arm 17 are respectively moved in the directions by the means (not shown), and the rotation of the first brake arm 10 and the second brake arm 17 is restricted. The power has been released.

Here, when the stop operation of the magnetic tape 5 is performed from the fast-forward or rewind operation at a high speed, the winding operation is stopped, and almost simultaneously with the stop of the winding operation, the second guide of the second brake arm 17 is driven by a driving means (not shown). The pin 20 is separated from the second drive plate 21 and the second brake shoe 18 comes into contact with the reel base 4 as described above. In addition to the reaction force of the second tension coil spring 19, the second brake arm 17 is elastic. The magnetic tape 5 is stopped by being deformed and digging into itself, and a braking force that does not lose the inertia of the reel base 4 that is driven and rotated at high speed acts.

[0017]

In the conventional reel stand braking device having the above-described structure, the restriction lead is provided when the magnetic tape withdrawal speed changes during the cassette mounting operation or during the loading operation or when the magnetic tape comes into contact with the cylinder. To prevent tape damage due to dropping from the surface or slack of the magnetic tape near the completion of loading, a dedicated brake component, namely, a first brake arm, a first brake shoe, and a pin serving as a rotation center, Therefore, many members such as an elastic member spring for braking force and a regulating means for regulating and operating the first brake arm are required, and the price as a product increases in terms of the number of parts and the number of assembly steps. there were.

Also, the point of application of the brake becomes point-contact on the reel base, and the state of contact between the brake member and the reel base becomes unstable, or the friction coefficient between the first brake shoe and the reel base varies. The braking load may vary greatly, and in some cases, an excessive braking load may act on the reel base, and as a result, the tape may be loaded with an excessive tape tension. Because the tape is loaded, tape damage may occur or the operation load may be excessive,
It was a big problem.

When stopping from fast-forwarding or rewinding at a high speed, a dedicated brake component having a large braking force, that is, a second brake arm, a second brake shoe, a pin serving as a rotation center, and a predetermined braking force There is a problem that many members such as an elastic member spring for use and a regulating means for regulating and operating the second brake arm are required, and the price as a product is increased in view of an increase in the number of parts and assembly man-hours.

Further, the point of application of the brake becomes point-contact on the reel base, and the state of contact between the second brake shoe and the reel base becomes unstable. (2) The braking load may vary greatly due to variations in the elastic deformation state of the brake arm, etc., and in some cases, an excessive braking load may act on the reel base, resulting in an excessive tape tension immediately before stopping, resulting in tape damage. In some cases, the braking force of the reel base may become too small, and depending on the inertia of the reel base on the driven side, there may be cases where the brake cannot be fully applied and the tape may loosen greatly, causing a serious problem. .

Therefore, the present invention has been made in view of such a conventional problem, and has a very simple structure with a greatly reduced number of parts, and is required during a cassette mounting operation or during a loading operation. The brake force of the reel base can be controlled arbitrarily to apply a stable reel base braking load, maintain an appropriate tape tension, and reduce tape slack during loading and tape damage due to excessive tension. In addition to preventing the occurrence of tape damage, it provides a stable reel base braking force with little variation when stopping from fast-forward or rewind at high speed, and moderates the tape tension at the time of stop to prevent tape damage. It is an object of the present invention to provide a highly reliable reel stand braking device that can prevent such a problem.

[0022]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention provides a reel base for supplying or winding a magnetic tape, a brake band wound around the reel base at a predetermined angle, and An elastic member that generates a corresponding reaction force,
At least one end of the brake band is held, one end of the elastic member is locked, and a braking force is applied to the reel base by utilizing a frictional force generated by tension of the brake band between the reel base and the brake band. The first arm is rotatable to a first position where the elastic member can be freely provided, a second position where the tension of the brake band is released and the frictional force on the reel base is released, and the other end of the elastic member is locked. And
At the first position of the first arm, the reaction force of the elastic member is changed to move the second arm rotatable to a rotation position at which arbitrary tension can be applied to the brake band, and the second arm is moved. A first cam portion for arbitrarily changing a reaction force of the elastic member; and a second cam portion for moving the first arm to the second position.
A first operation mode in which the braking force on the reel base is freely controllable by holding the first arm in the second position, and a second operation mode in which the braking force on the reel base is released by holding the first arm in the second position. It is characterized by comprising an operation mode switching conversion means capable of switching to an operation mode.

According to the present invention having such features,
It is possible to arbitrarily control the braking force as required during the cassette mounting operation or during the loading operation, apply a stable reel base braking load, maintain an appropriate tape tension, and reduce the tape slack during loading. The occurrence of tape damage due to excessive tension can be prevented. In addition, when stopping from fast forward or rewind at high speed, a stable reel base braking force with little variation is given,
The tape tension at the time of stoppage can be set to an appropriate value, and occurrence of tape damage can be prevented.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a reel base for supplying or winding a magnetic tape, a brake band wound around the reel base at a predetermined angle, and A frictional force generated by the tension of the brake band between the reel base and the brake band, while holding at least one end of the elastic band and an elastic member that generates a reaction force and at least one end of the elastic member. A first arm capable of applying a braking force to the reel base by utilizing a first arm, and a first arm rotatable to a second position capable of releasing the frictional force on the reel base by releasing the tension of the brake band. , The other end of the elastic member is locked, and the first
In the first position of the arm, the reaction force of the elastic member is changed,
A second arm rotatable to a rotation position at which arbitrary tension can be applied to the brake band, a first cam portion for moving the second arm and arbitrarily changing a reaction force of the elastic member, A first operation mode comprising a second cam portion for moving a first arm to the second position, wherein the first arm is held at the first position and a braking force on the reel base can be freely controlled. And an operation mode switching conversion means for holding the first arm at the second position and switching to a second operation mode for releasing a braking force on the reel base. The brake force can be arbitrarily controlled during the loading operation, etc., and a stable reel base braking load can be applied to maintain an appropriate tape tension. It is possible to prevent the occurrence of Pudameji, also in the case of stopping the fast forward or rewind at high speed, gives less stable reel base braking force variations,
This has an effect that the tape tension at the time of stoppage can be made appropriate and the occurrence of tape damage can be prevented.

An embodiment of the present invention will be described below in detail with reference to the drawings with reference to FIGS.

(Embodiment 1) FIG. 1 is a plan view showing a configuration of a main part of a magnetic recording / reproducing apparatus according to Embodiment 1 of the present invention, and FIG. FIG. FIG. 3 is a plan view of the part showing the fast-forward or rewind operation, and FIG. 4 is a plan view of the part showing the STOP operation from the fast-forward or rewind operation. The same parts as those in the conventional example will be described with the same reference numerals.

First, the overall configuration will be described. FIG.
, The capstan motor 1 is a rotation drive source of the take-up reel base 4 and the supply reel base 3. Both ends of the magnetic tape 5 are wound around two reels provided on the tape cassette 2. When the tape cassette 2 is loaded in the VTR, the magnetic tape 5 is pulled out by a mechanism (not shown) and wound around the cylinder 6. The magnetic tape 5 has a capstan shaft 7 and a pinch roller 8 during reproduction or reverse reproduction.
During rewinding or fast-forwarding, the pinch roller 8 is separated from the capstan shaft 7 and travels.

Next, a brake means for braking the rotation of the reel base 4 according to the present invention will be described with reference to FIG. The first rotation is performed around the support shaft 101 fixed to the base 13 as a rotation center.
An arm 102 is rotatably mounted. In addition,
Both ends of a brake band 103 wound around the reel base 4 at a predetermined angle are locked to the first arm 102. The second arm 104 is located at the center of rotation of the first arm 102.
Are coaxially engaged and are rotatable. One end of a tension coil spring 105 serving as an elastic member is locked to the first arm 102, and the other end is locked to the second arm 104, so that the tension coil spring 105 is pulled by the rotational positional relationship between the first arm 102 and the second arm 104. The expansion and contraction amount of the coil spring 105 changes.

Further, the first arm 102 and the second arm 104 are integrally formed with a first follower 107 and a second follower 108 for regulating the rotation position. The operation mode conversion means 106 is movably attached to the base 13, and includes a first follower 107 and a second follower 108.
Can be independently driven, and the rotation positions of the first arm 102 and the second arm 104 can be regulated respectively.

An example of the operation of the magnetic recording / reproducing apparatus of the present embodiment configured as described above will also be described with reference to FIGS. 1, 2, 3 and 4.

First, in the tape cassette 2, the operation of mounting the cassette on the reel bases 3 and 4 while releasing the brake in the cassette provided so that the magnetic tape 5 does not slack, is described below. Is suddenly released, the unwound magnetic tape 5 deviates outside the tape cassette 2 and largely slackens, and the magnetic tape 5 falls from the height regulating member. In order to prevent tape damage, at the time of cassette mounting operation, the operation mode conversion means 106 is moved in the direction of arrow G by a driving means (not shown), and the operation mode of the first follower 107 of the first arm 102 is changed. The first arm 102 is released from the rotation restricted state by being separated from the first cam surface 109 of the conversion means 106. That.

The second follower 1 of the second arm 104
In 08, the second arm 104 is moved so as to rotate by a predetermined angle in the direction of the arrow H by the engagement of the operation mode conversion means 106 with the second cam surface 110. Therefore, the tension coil spring 105 suspended between the first arm 102 and the second arm 104 is expanded and contracted to a position corresponding to the amount of rotation of the second arm 104. Here, the first arm 102 is rotated counterclockwise by a reaction force corresponding to the amount of expansion and contraction of the tension coil spring 105, and receives the reaction force of the tension coil spring 105 at a position where the slack of the brake band 103 is eliminated. As a result, a counterclockwise turning moment acts.

In this case, tension corresponding to the turning moment of the first arm 102 acts on the brake band 103 wound around the reel base 4, and a tension coil is applied between the reel base 4 and the brake band 103. The frictional force corresponding to the reaction force of the spring 105 acts to apply a braking force. When the cassette is completely mounted, the braking force is applied to the reel base 4, so that the magnetic tape 5 It is not sagging.

Next, when the loading operation is performed after the cassette has been mounted, the tape pull-out member is driven by the driving means (not shown), the magnetic tape 5 is pulled out and wound around the cylinder 6, and the reproduction / recording traveling is stabilized. The operation of pulling out the magnetic tape 5 is continued until it is positioned so that it can be performed.

At this time, if the braking force is not applied to the reel base 4, the tension of the magnetic tape 5 pulled out becomes very small, so that during the loading operation, when the magnetic tape 5 comes into contact with the cylinder 6, When the magnetic tape 5 falls from the regulating lead surface of the cylinder 6, the magnetic tape 5 sags when the drawing speed of the magnetic tape 5 changes during the loading operation, the magnetic tape 5 falls from the height regulating member, or the vicinity of the completion of the loading operation. Due to the inertia of the sent magnetic tape 5 and the reel base 4 rotation, the magnetic tape 5 is too much out,
The magnetic tape 5 was so damaged that the magnetic tape 5 was largely deviated from the running path, that is, the tape was damaged.

Therefore, during the loading operation from when the cassette is mounted to when the loading is completed, as in the case of mounting the cassette, the second cam surface 110 of the operation mode converting means 106 and the second arm 104 of the second arm 104 are operated in the same manner as described above. Follower 1
By setting the cam relation of 08 to an appropriate one, a braking load is applied to the reel base 4 in the same manner as the above-described operation,
By applying a predetermined tension to the magnetic tape 5 to be pulled out, the height of the magnetic tape 5 that occurs when the magnetic tape 5 falls from the regulating lead surface when the magnetic tape 5 comes into contact with the cylinder 6 or when the drawing speed of the magnetic tape 5 changes. This prevents the magnetic tape 5 from sagging due to falling out of the restricting member or excessive rotation of the reel base 4 due to inertia of the rotation of the reel base 4.

The braking means for stopping the magnetic tape 5 from fast forward or rewind at high speed will be described with reference to FIGS. 3 and 4. FIG.

First, in the fast-forward or rewind operation at high speed, the reel base on the winding side must be driven to rotate at high speed. At this time, since the winding load on the driven reel unit must be minimized, the braking force is normally released from the driven reel unit.
In this case, the operation mode conversion means 106 is further moved in the G direction by means not shown, and the first cam surface 10
9 moves the first follower 107 of the first arm 102, and rotates the first arm 102 clockwise regardless of the reaction force of the tension coil spring 105, whereby the position is regulated.
For this reason, in the brake band 103, a slack occurs and tension is lost, so that no braking force is applied to the reel base 4, and the braking force is released during a fast-forward or rewind operation at a high speed. are doing.

When the stop operation of the magnetic tape 5 is performed from the fast-forward or rewind operation, the operation mode conversion means 106 is moved in the direction of arrow G by a driving means (not shown) almost simultaneously with stopping the winding operation. , First follower 107 of first arm 102 and operation mode conversion means 1
06 is separated from the first cam surface 109, the first arm 102 is rotatable, and a turning moment according to the reaction force of the tension coil spring 105 is applied.

In the second follower 108 of the second arm 104, the tension of the brake band 103 is applied so that the brake can be applied even when the reel base 4 is rotating at high speed during fast-forwarding or winding. The second arm 1 is lifted by the second cam surface 110 of the operation mode converting means 106.
04 is rotated in the counterclockwise direction by a predetermined angle, and the tension coil spring 105 can obtain a large reaction force according to the amount of expansion and contraction, and a braking force that is not inferior to the inertia of the reel base 4 rotating at high speed. To work.

According to the first embodiment of the present invention having the above-described construction, a stable and optimum operation can be achieved even during the loading operation from the time of loading the cassette to the completion of loading without adding a dedicated brake member. Since a large braking load can be applied to the reel base 4, the magnetic tape 5 sags when the cassette is mounted, drops from the cylinder regulating lead surface during the loading operation, and changes in the pull-out speed of the magnetic tape 5 during loading. At the time of dropping from the height regulating member and near the completion of the loading operation, it is possible to prevent the magnetic tape 5 from being slackened due to excessive rotation of the reel base 4 due to the inertia of the rotation. 5, the tension of the magnetic tape 5 can be changed to the optimum tension as needed in response to the change in the pull-out speed of the tape 5. It is possible to prevent the damage from occurring.

Even in the case of a change in the speed of pulling out the magnetic tape 5 during the loading operation, the second
By optimizing the engagement relationship between the second follower 108 of the arm 104 and the second cam surface 110 of the operation mode conversion means 106 and arbitrarily changing the reaction force of the tension coil spring 105 during the loading operation, The braking force of the reel base 4 corresponding to the change of the pull-out speed of the tape 5 can be changed arbitrarily.

The holding position of the brake band 103 on the first arm 102 is changed from the direction in which the tension is applied to the brake band 103 on the high tension side of the brake band 103 in the rotation direction in which the magnetic tape 5 of the reel base 4 is sent out. The first distance that is the shortest distance of the one arm 102 to the rotation spindle 101
From the shortest distance and the direction of the tension acting on the brake band 103 which is on the low tension side of the brake band 103, the first arm 10
The second shortest distance, which is the shortest distance to the second rotation support shaft 101, is arranged so that the first shortest distance is smaller than the second shortest distance. Can be made larger than the braking force of the reel base in the winding rotation direction of the magnetic tape 5, so that the braking force of the driven reel base in the rotation direction can be increased. An operation equivalent to this type of brake device can be obtained.

Therefore, as in a conventional device of this type, a dedicated brake component, that is, a brake arm and a center of rotation, which are necessary for applying a braking force to the reel base during mounting of a cassette or during loading. Many members such as pins, tension coil springs for predetermined braking force, and regulating means for regulating the brake arm,
Dedicated brake components required when stopping from fast forward or rewind operation at high speed, namely, brake arm, pin at the center of rotation, tension coil spring for predetermined braking force, and regulating operation of brake arm Many members such as regulating means to be eliminated can be eliminated, and the same function can be provided with a simple configuration, so that the number of parts can be greatly reduced, and the number of assembly steps is reduced with the reduction of the number of components, As a result, the cost can be significantly reduced.

Further, as compared with the conventional two kinds of brake members, a band brake is used, and a braking load is applied by a pressure acting over the winding angle, so that the conventional point contact or partial pressing is applied. As compared with the block type brake, a stable braking load with less variation can be expected, and there is an advantage that damage to the magnetic tape is prevented from occurring.

Further, as compared with the conventional two types of brake shoes of the dedicated brake member, the surface pressure of the contact portion with the reel base is relatively low due to the action over the winding angle, so that the reliability such as the service life is reduced. There is an advantage that the performance is improved as compared with the conventional method.

[0047]

As described above, according to the reel stand braking device of the present invention, an arbitrary reel stand braking load can be obtained as required even when a cassette is mounted or during a loading operation until loading is completed. As a result, tape slack when loading the cassette, dropping of the magnetic tape from the cylinder regulating lead surface during the loading operation, and dropping and loading operation from the height regulating member when the magnetic tape withdrawal speed changes during loading In the vicinity of completion, slack due to excessive protrusion of the magnetic tape caused by inertia of rotation of the reel base can be prevented, and tape damage can be prevented.

In the case of stopping from fast-forwarding or rewinding at a high speed, a stable braking force is applied to the reel base with a small variation, the tape tension at the time of stopping is made appropriate, and the slack of the magnetic tape is prevented. The occurrence of tape damage can be prevented.

Therefore, like a conventional device of this type,
Dedicated brake components necessary for applying a braking force to the reel base during a cassette mounting operation or during a magnetic tape loading operation, that is, a brake arm, a pin at the center of rotation, and a pull for a predetermined braking force. Many members such as a coil spring and a regulating means for regulating the brake arm can be eliminated, and a dedicated brake component required when stopping from a high-speed fast-forward or rewind operation, that is, a brake arm, Many members such as a pin at the center of rotation, a tension coil spring for a predetermined braking force, and a regulating means for regulating the brake arm can be eliminated, and the number of components can be greatly reduced, thereby reducing the number of components. Accordingly, the number of assembling steps is reduced, and the cost is significantly reduced.

In addition, since a band brake is used and a braking load is applied by the pressure acting over the winding angle, a stable braking load with less variation is obtained as compared with the conventional point contact or partial pressing block type brake. And the surface pressure of the contact portion on the reel base is relatively low due to the action over the winding angle as compared with the conventional two types of dedicated brake shoes. There is an advantage that the reliability of the conventional method is improved as compared with the conventional method.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of a reel stand braking device of the present invention.

FIG. 2 is a plan view of a relevant portion of the reel stand braking device, showing an operation when the cassette according to the present invention is mounted.

FIG. 3 is a plan view of a relevant portion of the reel stand braking device showing a fast-forward or rewind operation of the present invention.

FIG. 4 is a plan view of the relevant portion of the reel stand braking device, showing an operation from fast-forward or rewind to stop according to the present invention.

FIG. 5 is a plan view showing a schematic configuration of a conventional reel stand braking device.

FIG. 6 is a plan view of a relevant portion of the reel stand braking device, showing an operation when a cassette is mounted in the related art.

FIG. 7 is a plan view of a relevant portion of a reel base braking device showing a fast-forward or rewind operation according to the related art.

FIG. 8 is a plan view of the relevant portion of the reel stand braking device showing the operation of the conventional art from fast-forward or rewind to stop.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 capstan motor 2 tape cassette 3 supply-side reel base 4 take-up reel base 5 magnetic tape 6 cylinder 7 capstan shaft 8 pinch roller 9 first support shaft 10 first brake arm 11 first brake shoe 12 first tension coil Spring 13 Base 14 First guide pin 15 First drive plate 16 Second support shaft 17 Second brake arm 18 Second brake shoe 19 Second tension coil spring 20 Second guide pin 21 Second drive plate 101 Support shaft 102 First Arm 103 Brake band 104 Second arm 105 Tension coil spring 106 Operation mode conversion means 107 First follower 108 Second follower 109 First cam surface 110 Second cam surface

Continuation of the front page (56) References JP-A-3-296949 (JP, A) JP-A-51-43113 (JP, A) JP-A-63-72734 (JP, U) JP-A-5-21343 (JP, A) , U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 15/18 G11B 15/22

Claims (2)

(57) [Claims] And 1. A substrate, a reel base for supplying or winding of the magnetic tape, a brake band which is wound a predetermined angle around the said reel table, a capstan which is rotatably provided on the substrate, wherein By holding the capstan and the magnetic tape
A pinch roller for transferring the magnetic tape; and a first pinch roller rotatably provided on the substrate.
A first arm having a lower portion, and a second arm provided at one end of the first arm so as to be rotatable on the substrate.
A second arm having a lower portion, one end of which is the first arm, and the other end of which is the second arm
A locked elastic member, and a reciprocally movable member provided on the substrate.
Operating mode switching conversion means having a cam portion and a second cam portion.
A reel base braking device having at least one end of the brake band with the first arm
And the first arm is connected to the brake van by the elastic member.
The operation mode switching conversion means is configured to urge the first cam portion into the first direction.
The first arm is moved forward by contacting the follower.
The braking force is applied to the reel base by the tension of the brake band.
Release the first position and the tension of the brake band
And a second position for releasing the braking force on the reel base.
Controlling the second cam portion and the second follower portion.
The position of the second arm is controlled by the contact of
Controls the amount of expansion and contraction of the sexual member, from the time of cassette loading until loading operation is completed, the
The first arm is moved to the second
1 position, the second arm is restricted to a predetermined position, at the time of fast-forward or rewind operation at high speed, the dynamic
The first arm is connected to the second arm by the operation mode switching conversion means.
The position, the capstan and said Pinchiro La away
From the fast-forward or rewind operation at high speed.
Is stopped by the operation mode switching conversion means,
The said 1st arm is moved to the said 1st position, The reel stand braking device characterized by the above-mentioned . 2. The brake band is held at a first position of a first arm in a direction in which a magnetic tape is sent out from a reel base in a rotation direction of the magnetic tape. A first shortest distance that is the shortest distance to the rotation fulcrum of the first arm is a shortest distance from the direction of the tension action of the brake band that is on the low tension side of the brake band to the rotation fulcrum of the first arm. 2. The reel stand braking device according to claim 1, wherein the first arm is arranged to be smaller than the shortest distance.