JPS5928523Y2 - Automatic stop device for cassette tape recorder - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an automatic stop device for a cassette tape recorder that automatically stops each operation such as fast forwarding and rewinding.

In general, when a cassette tape recorder runs out of tape on the rewind side reel of the tape cassette under various operating conditions, the end of the tape is fixed to the reel, so if the tape continues to operate, the end of the tape is fixed to the reel. There is a problem that the tape may be deformed or damaged, and on the tape recorder side, too, there is a problem that strain is applied to the motor and power is consumed unnecessarily.

Incidentally, a device has already been developed that automatically stops when the rewind side reel runs out of tape during recording or playback operation.

In other words, the tape tension detection lever contacts the tape in the tape cassette together with the magnetic head, and the tape is bent in the shape of a "<" at the abutting part. Move the detection lever to the outside of the cassette with the tension of
The release lever is positioned on the orbit of a drive pin provided with a flywheel, and the drive pin, that is, the flywheel moves the lock plate in the release direction via the release lever, and is locked in the operating position by the lock plate. The playback button, the recording button, etc. that have been pressed are returned to their initial positions.

However, during fast-forwarding, rewinding, and other operations, the magnetic head is separated from the tape in the cassette, and the tape tension detection lever, which is attached to the head board, is also separated from the tape. Therefore, it was necessary to develop other means to stop operating conditions such as fast forwarding and rewinding.

This idea was made in view of these problems, and the head board is placed on the reaction force setting side (for fast forwarding, rewinding, etc.).
In this operating state, when there is no tape on the rewind side reel of the tape cassette, it will automatically stop. O1 Automatic stop of the cassette tape recorder prevents damage to the magnetic tape and unnecessary power consumption. It provides equipment.

An embodiment of this invention will be described below with reference to FIGS. 1 to 3.

A pair of friction boots 'J4a, 4 each having reel shafts 3a, 3b into which the tape cassette 2 is loaded is located in the center of the main board 1.
b is rotatably mounted.

An idler pulley 6 pivotally supported by the swing lever 5 is arranged between the two boos J4a and 4b, and further,
Between the friction boob 4a on the supply reel side and the idler pulley 6, there is a transmission pulley 8 which is supported by a forward/backward lever 7ζ.
is located.

A feed lever 90 is located near the friction pulley 4b on the take-up reel side.
A small-diameter constant-speed drive pulley 10 supported by a shaft is arranged.

At the front end of the main board 1, push buttons 11a to 11f for various operations are arranged side by side, and a push button operation switching mechanism 12 is provided.

A lock plate 13 as a locking member is provided below the push buttons 11a to 11f so as to be movable back and forth in the left and right direction, and each push button has a hook-shaped locking portion 14a to 14f cut out in the lock plate 13. locked in operating position.

However, the stop button 11e (the corresponding locking part 14e is a single G
The eject button 11f (the locking portion 14f opposite to the eject button 11f) is formed with an inclined surface that slides on the stop push button 11e and moves the lock plate 13 in the release direction.
There is no gap in the notch for escaping f.

A magnetic head 15 and a pinch roller 16 are disposed between the two friction boots J4a, 4b and the push button operation switching mechanism 12.
The head board 17 on which the reel shafts 3a, 3, etc. are attached
It is provided so as to be freely movable forward and backward relative to the tape cassette 2 loaded in the tape cassette 2.b.

The head substrate 17 is further provided with a tape tension detection lever 20, which has a contact portion 19 at one end that contacts the magnetic tape 18 in the tape cassette 2, and is rotatable about its central portion as a fulcrum. .

The other end ζ of this detection lever 20 is implanted with an engagement pin 21 that protrudes from the back side of the main board 1.

A capstan shaft 22 is rotatably attached to the main board 1 in front of the pinch roller 16, and a flywheel 23 is attached to the lower end of the capstan shaft 22 on the back side of the main board 1. Furthermore, a cam pulley 31 is rotatably mounted below the flywheel 23.

The following cam mechanism 33 is constituted by the cam pulley side cam formed at the rotational center of the upper surface of the cam pulley 31 and the flywheel side cam formed at the rotational center of the lower surface of the flywheel 23.

That is, a cylindrical and linear cam surface 23a is formed at the center of the lower surface of the flywheel 23, and a cylindrical and linear cam surface 23a is formed at the center of the upper surface of the cam pre-31.
A spiral cam surface 31a having the same inclination angle as a is formed.

7, a protrusion 23b is provided at the top end of each cam surface, respectively.
31b is formed.

A compression coil spring 34 as a first friction mechanism is inserted between the cam pulley 31 and a support plate 32 that supports the lower end of the capstan shaft 22. They are pressed into contact with each other, and the two rotate together.

A first drive pin 24 is provided protruding from the upper surface of the flywheel 23 .

Further, a second drive pin 35 is provided protruding from the lower surface of the cam pulley 31.

The flywheel 23 is rotated by a motor 25 attached to the rear end of the main board 1 via an endless belt 26.

A tension pulley 28 attached via a friction mechanism 27 is in pressure contact with the endless belt 26 at the lower end of the shaft of the constant speed drive pulley 10.

At the lower end of the support shaft 29 to which the idler pulley 6 is attached, a middle cylindrical pulley 30 that comes into contact with and separates from the cam pulley 31 is supported rotatably and freely up and down.

A receiving plate 36 is attached to the support shaft 29 above the intermediate pulley 30, and a friction plate 37 such as felt is interposed between the receiving plate 36 and the intermediate pulley 30, and a friction plate 37 such as felt is interposed between the lower end of the support shaft 29 and the intermediate pulley 30. A compression coil spring 381 as a second friction mechanism is wound between the compression coil spring 381 and the intermediate pulley 30, thereby biasing the intermediate pulley 30 in the direction of the receiving plate 36, whereby the idler pulley 6 and the intermediate boolean IJ30 are connected to the compression coil spring 381. The friction transmission of the compression coil spring 38 (the second friction mechanism), which is stronger than the friction transmission of the compression coil spring 34 (that is, the first friction mechanism), causes the two to rotate together.

The back surface of the main board 1 supports the central portion of the release lever 41 in a rotatable manner.

This lever 41 is pivoted in one direction by a link 42, and its front half is bifurcated, with one leg 43 extending toward the upper surface of the flywheel 23 and the other leg 44 extending toward the lower surface of the cam pulley 31. Further, the rear end portion thereof extends and forms a suppressing piece 45 that faces the pressing protrusion 13a protruding from the lock plate 13.

The engagement pin 21 of the tape tension detection lever 20 is located between the bases of the legs 43, 44.

Also, one leg 43 is normally located outside the orbit of the first drive pin 24 protruding from the flywheel 23, but when the tape tension detection lever 20 rotates, the engagement pin 21 It is rotated so that it is positioned on the orbit of the drive pin 24.

Further, the other leg 44 is in a position where it is pressed and rotated by the second drive pin 35 when the cam pulley 31 moves downward.

Next, by explaining the operation of this embodiment, the usurpation of each part will be further clarified.

First, when the playback button 11d is pressed, the head board 17 moves toward the tape cassette, and the magnetic head 15
, the pinch roller 16 and the tape tension detection lever 20 come into contact with the magnetic tape 18 in the cassette 2.

Therefore, the magnetic tape 18 is bent in the shape of a "<" at the contact portion 19 of the detection lever 20.

Further, the feed lever 9 also rotates in conjunction with the suppressing operation of the regeneration button 11d, and at the same time the constant speed drive pulley 10 comes into pressure contact with the friction boob IJ4b# on the take-up reel side, the main switch (not shown) is also turned on. , the motor 25 rotates, and this rotational force is transmitted to the friction boo IJ4b, that is, the reel shaft 3b on the winding side, via the endless belt 26, the tension pulley 28, and the constant speed drive pulley 10, and at the same time the flywheel 23
, that is, the capstan shaft 22 rotates, and the magnetic tape 1
8 is sandwiched between a capstan shaft 22 and a pinch roller 16 and fed at a constant speed.

Note that the playback button 11d is held in the operating position by the locking portion 14d of the lock plate 13.

To perform a recording operation, the playback button 11d and the recording button 11a may be pressed at the same time.

In this case as well, in addition to the above operations, a recording switch (not shown) is turned on and predetermined operations are performed.

Double push button 11a. 11d is held in the operating position by the lock plate 13.

During playback or recording, tape cassette 2
When the rewind side reel (in this case, the supply IJ reel) runs out of tape, the tape tension increases rapidly because the end of the tape is fixed to the reel.

Therefore, with this tension, the tape tension detection lever 2
0 rotates when the contact portion 19 is pressed, and the engagement pin 21
This positions the leg 43 of the release lever 41 on the orbit of the second drive pin 24 of the flywheel 23.

Therefore, the release lever 41 is pushed around by the drive pin 24, and its pressing piece 45 presses the pressing protrusion 13a of the lock plate 13, thereby moving the lock plate 13 in the release direction.

As a result, the playback button 11d and the recording button lla are unlocked and returned to their initial positions, and in conjunction with this, the head board 17 and feed lever 9 are also returned to their initial positions, and the main switch is also turned off and the motor is turned off. 25 stops.

Next, to perform a fast forward operation, the fast forward button 11C can be pressed.

In this case, the swing lever 5 is interlocked with the pressing operation of the button 11c, the intermediate pulley 8 is brought into pressure contact with the flywheel 23, and the idler pulley 6 is pressed against the friction boot I on the take-up reel side.
Press into contact with J 4 b.

In addition, the main switch is also turned on and the motor 25 rotates, and this rotational force is transmitted to the friction boob IJ4b, that is, the reel shaft 3b on the winding side, via the endless belt 26, intermediate pulley 30, and idler pulley 6. , the tape 18 is wound onto the take-up reel at high speed.

When there is no tape on the unwinding reel (in this case, the supply reel) of the tape cassette 2, the take-up reel is forcibly stopped from rotating because the end of the tape is fixed to the reel.

Therefore, the idler pulley 6, intermediate pulley 30, and cam pulley 31 stop, but the flywheel 23 is forced to rotate further.

Therefore, first, the flywheel 23 and the cam pulley 31
A slip occurs between them, and the cam pulley 31 descends against the spring 24 due to the subsequent sliding engagement between the flywheel side cam and the cam pulley side cam.

Then, when the second drive pin 35 provided on the cam pulley 31 moves to a position where it engages with the release lever 41, the protrusions 23b and 31b of both cams engage with each other in the rotational direction. rotates integrally with the flywheel 23, the drive pin 35 pushes the release lever 41, and the pressing piece 45 of the release lever 41 rotates.
to move the lock plate 13 in the release direction and press the fast forward button 1.
Return 1C from its operating position to its initial position.

Accordingly, the swing lever 5 returns to its initial position to separate the intermediate pulley 30 and idler pulley 6 from the cam pulley 31 and friction pulley 4b, respectively, and the main switch is also turned off to stop the motor.

When performing a rewind operation, the rewind button 11b may be pressed in the same manner.

Then, the swinging lever 5 and the forward/backward lever 7 are interlocked, and the transmission pulley 8 attached to the forward/backward lever 7 comes into pressure contact with the friction pulley 4al on the supply reel side, and the idler pulley 6 and The intermediate pulley 30 connects to the transmission boo IJ 8 and the flywheel 23, respectively.
The main switch is also turned on and motor 2
5 rotates, and this rotational force is transmitted to the friction boo 'J4a, that is, the reel shaft 3a on the supply side, via the endless belt 26, intermediate pulley 30, idler pulley 6, and transmission pulley 8, and the tape 18 is transmitted to the reel shaft 3a on the supply side. It is rewound onto the reel at high speed.

When there is no tape on the unwinding reel (in this case, the take-up reel) of the tape cassette 2, the supply reel stops rotating because the end of the tape is fixed to the reel.

As a result, the idler pulley 6, intermediate pulley 30, and cam pulley 31 also stop, but since the flywheel 23 is further forcibly rotated, the cam mechanism 33 works to lower the cam pulley 31, as in the previous case. When the cam pulley 31 starts rotating together with the flywheel 23 again, the second drive pin 35, which is integral with the cam pulley 31, further rotates the release lever 41 to move the lock plate 13 in the release direction, and presses the rewind button 11b. Return to initial position.

Therefore, the swing lever 5 and the forward/backward lever 7 also return to their initial positions, the main switch is turned off, and the motor 25 is stopped.

Next, another embodiment shown in FIG. 4 will be described.

1. The same parts as in the above embodiment are given the same reference numerals, and detailed explanations will be omitted.

In this embodiment, the two drive pins 2 in the previous embodiment are
4.35, and one drive pin 49 serves as the same.

That is, the flywheel 23 of the capstan shaft 22
A cam pulley 31 is mounted below to be rotatable and movable up and down, a plate-shaped friction body 47 is arranged between the cam pulley 31 and the flywheel 23, and a plate-shaped friction body 47 is arranged between the friction body 47 and the flywheel 23. O compression coil spring 34
Interpose.

A through hole 48 parallel to the capstan shaft 22 is formed in a part of the flywheel 23, a driving pin 49 serving as a driving body is provided protruding from the friction body 47, and the driving pin 49 is inserted into the through hole 48. It is made to protrude to the upper surface side of the flywheel 23 through the flywheel 23.

Furthermore, a cam mechanism 50 composed of a cam pulley side cam and a flywheel side cam is provided on the lower surface side of the cam pulley 31.

That is, at the center of the lower surface of the cam pulley 31, there is a cylindrical cam 51 having a protrusion at the top end and a linear cam surface from the lower surface.
A cam body 52 is attached to the lower end of the capstan shaft 22. The cam body 52 has a protrusion at the top end and has an upper surface having a cam surface having the same angle of inclination as the cam surface.

The drive pin 49 is normally connected to the flywheel 2.
3 Although the length protruding from the top surface is short, the idler pulley 6,
The load on the intermediate pulley 30 increases and the cam pulley 31
When the drive pin 49 stops, the cam body 52 rotates together with the flywheel 23 and pushes up the cam pulley 31, thereby increasing the length of the drive pin 49 projecting from the top surface of the flywheel 23.

Furthermore, when the protrusion length of the drive pin 49 is short,
One leg 43 of the release lever 41 rotated by the tape tension detection lever 20 is connected to this drive pin 49.
When the cam pulley 31 rotates integrally with the flywheel 23 due to the engagement of the protrusions, the other leg 43 of the release lever 41 This drive pin 49 comes to engage.

Therefore, when there is no tape on the rewind reel during playback or recording, the tape tension detection lever 20 rotates in response to the tension of the tape, and the release lever 41 is moved onto the trajectory of the drive pin 49. Then, the drive pin 49 moves the lock plate 13 in the release direction via the release lever 41.

In addition, in operating conditions such as fast forwarding and rewinding, when the reel on the rewinding side runs out of tape, the cam pulley 31 stops, and together with the flywheel 23 (the rotating cam body 52 is pushed up, the drive pin 49 rises, the drive pin 49 pushes the other leg 44 of the release lever 41, and the release lever 41 moves the lock plate 13 in the release direction.

In addition, according to each of the above embodiments, the cassette automatically stops when the tape on the rewind side reel runs out even in the recording and playback operation state, but this invention is not limited to this, and the point is that the magnetic It has a feature that it automatically stops when the head is away from the tape, such as fast forwarding or rewinding.

As described above, this invention, when an excessive load is applied to the reel shaft, first causes slip between the flywheel and the cam pulley installed coaxially with the flywheel, and then the flywheel side cam and the cam pulley side cam. The cam pulley is moved in the axial direction by mutual sliding, and the drive body protruding from the cam pulley is moved to a point where the release lever is positioned on its revolution orbit, and then both cams are moved in a spiral shape. The cam pulley is rotated together with the flywheel again by engagement of the protrusions provided at the top end of the cam surface, so that it automatically stops when the rewind side reel runs out of tape. It is.

According to this invention, even in each operating state I of temporary fast forwarding and temporary rewinding, when there is no tape on the rewinding reel, the tape automatically enters the stopped state.

That is, to explain the above embodiment, in the case of temporary fast forwarding, the fast forwarding button 11c is pressed while the playback button 11d is pressed, and in the case of temporary rewinding, the playback button 1 is pressed.
Since the rewind button 11b is pressed while pressing 1d, when there is no tape on the rewind reel, the cam pulley detects that the take-up reel has stopped and the cam mechanism is activated, as described above. will be automatically stopped.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing one embodiment of this invention, Fig. 2 is a back view of the same embodiment, Fig. 3 is a sectional view of the main part of the same embodiment, and Fig. 4 is a plan view showing an embodiment of the invention.
The figure is a sectional view of a main part of another embodiment.

Claims (1)

[Claims for Utility Model Registration] A flywheel attached to a capstan shaft and driven to rotate by a motor, and a flywheel provided so as to be movable in the axial direction with respect to the flywheel with its rotation center aligned with the rotation center of the flywheel. , the rotational force of the cam pulley is transmitted by the friction transmission of the fourth friction mechanism (from which the cam pulley rotates integrally with the flywheel and the friction transmission of the second friction mechanism, which is stronger than the friction transmission in the first friction mechanism) A release lever is provided to protrude from the reel shaft and the cam pulley.The release lever rotates so that when the drive body and the cam pulley move in the axial direction relative to the flywheel σ, the drive body is positioned on the revolution track groove of the drive body. When the push buttons for various operations are locked in the operating position and the release lever is positioned on the orbit of the drive member, the drive member (which is driven via the release lever and releases the push button from the operating position) a stop member, a flywheel-side cam provided at the center of rotation of the flywheel and comprising a linear cam surface and a protrusion formed at the top end of the cam surface, and a cam provided at the center of rotation of the cam pulley. The cam pulley side cam is comprised of a spiral cam surface and a protrusion formed on the top end of the cam surface, and when an excessive load is applied to the reel shaft, the flywheel and cam pulley are first A slip is caused, and then the cam pulley is moved in the axial direction by sliding between the flywheel-side cam and the cam pulley-side cam, and the drive body is moved to a point where the release lever is located on its revolution orbit. An automatic stop device for a cassette type tape recorder, characterized in that the cam pulley is then rotated together with the flywheel again by engagement of the protrusions of both cams.