JPH0610512Y2 - Operation mode switching mechanism of tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an operation mode switching mechanism of a tape recorder capable of easily switching between recording and reproducing modes.

(Prior art and its problems) Conventionally, in a mechanism of a small tape recorder which is premised on the use of a dry battery, a recording mechanism using an AC erasing head is used in view of cost, space, power consumption and the like. .

However, while such a mechanism is advantageous in terms of power consumption, cost, etc., in the playback mode in which the erasing head is not used, only the erasing head has to be separated from the tape, and the recording / reproducing head and the erasing head are separately and It has the drawback that it must be controlled mechanically, and its mechanism becomes complicated. Especially, because of its good operability, the motor shift mechanism in which the operation mode is switched by the motor, which has become the mainstream these days, is recorded and reproduced. A separate cam is provided for the control mechanism for the head and the control mechanism for the erasing head,
In particular, the recording / playback switching mechanism is complicated, such as requiring a complicated control mechanism, which is a major drawback of the motor shift mechanism using the DC erasing head.

(Object of the Invention) The present invention has been made to eliminate the above-mentioned drawbacks, and an object thereof is to simplify the recording / playback switching mechanism in the operation mode switching mechanism of the motor shift mechanism using the DC erasing head.

(Outline of the Invention) A head chassis provided with a magnetic head for recording / reproducing and arranged movably between a stop position and a recording / reproducing position capable of recording / reproducing with the magnetic head pressed against a magnetic tape, A drive gear rotated by a motor, a cam disc rotated by the drive gear to control the movement of the head chassis to the respective positions, and a rotational position of the cam disc corresponding to each movement position of the head chassis are locked. A trigger lever and an electromagnet that controls this trigger lever,
The erasing head has an erasing head mounted thereon and an operating plate which is controlled by the trigger lever and engages with the head chassis to control the erasing head lever when the recording mode is set. By changing the excitation mode according to the setting, the movement path of the trigger lever with respect to the cam board is changed, and when the recording mode is set, the operating plate is engaged with the head chassis via the trigger lever and the operating plate is moved. An operation mode switching mechanism of a tape recorder which is configured to control an erasing head lever for mounting an erasing head via the recording / playback switching mechanism.

(Example) As an example, a stop position provided with a magnetic head, a recording / playback position where the magnetic head is pressed against the tape, and a music selection position where the magnetic head is slightly retracted and the magnetic head is slightly contacted with the tape are provided. The case where the present invention is applied to a tape recorder that can be used will be described below.

9 to 11 are plan views of the tape recorder of the present invention, in which 1 is a chassis, 2a and 2b are reel stands, and 3a and 3b are capstans. Flywheels 4a and 4b are attached to the capstans 3a and 3b so as to rotate integrally, and are connected by a pulley 6 of a motor 5 and a belt 7 so as to rotate in mutually opposite directions. Reference numeral 8 is a regulating pulley for the belt 7.

On the chassis 1 facing the capstans 3a, 3b, pinch roller levers 10a, 10b each having rotatably arranged pinch rollers 9a, 9b are rotatably attached by shafts 11a, 11b.

For the pinch roller levers 10a and 10b, use the capstan 3
Springs 12a and 12b for press-contacting a and 3b, a head chassis 14 described later, and a tape running direction switching lever 6
Pins 101a and 101b for controlling contact and separation with the capstans 3a and 3b by 0 are provided.

On the chassis 1 between the reel stands 2a and 2b, a head chassis 14 having a recording / reproducing head 13 attached is provided with long holes 14a-1.
4c, the pins 15a and 15b on the chassis 1 and the bearing 16b of the capstan 3b are arranged so as to be slidable back and forth, and are always urged downward by the spring 67 as seen in the figure, and both ends thereof are in a stopped state. In, there are formed engaging portions 141a, 141b for pushing down the pins 101a, 101b of the pinch roller levers 10a, 10b to separate them from the capstans 3a, 3b.

A notch 142 is formed in the central portion of the head chassis 14, and engagement protrusions 143 and 144 are cut and raised downward,
It is engaged with an engaging portion 18a at one end of a lever 18 described later. A lock lever 5 to be described later is provided on the right side of the long hole 14a.
An engagement protrusion 145 for releasing the lock of No. 1 is formed.

Head guides 20a, 20b for guiding the movement of the erasing heads 19a, 19b are attached to both sides of the recording / reproducing head 13, and tape guides 201a, 201b are attached to the respective head guides 20a, 20b.
Are formed. 202a and 202b are erase heads 19a and 19b.
Is an engaging portion for restricting the protrusion amount of the.

On the other hand, the erasing heads 19a and 19b are rotatably attached to both ends of the lever 21 with their long holes 191a and 191b, respectively.
The center point 1 of the rotary arm 22 is rotatably attached to one end of a rotary arm 22 by a shaft 23, and the other end of the rotary arm 22 is rotatably arranged on a shaft 11a of a pinch roller lever 10a.

The lever 21 is provided with pins 211a and 211b for engaging the tape running direction switching lever 60, which will be described later, to perform the seesaw operation of the erasing heads 19a and 19b. Detailed operation will be described later.

FIG. 8 shows the back surface of the tape recorder. Reference numeral 30 denotes a head chassis 14, a stop position ST at which the head 13 is separated from the tape T, a recording / reproducing position RP at which the head 13 is pressed against the tape T, and a head 13. Is a head chassis control mechanism for slightly retreating from the recording / playback position and making light contact with the tape to a music selection position MS where music selection is possible, and 31 is a pinch roller lever depending on the tape running direction.
This is a tape running direction switching mechanism for controlling the tape running direction switching lever 60 for switching the rotation directions of the reel bases 10a, 10b and the reel bases 2a, 2b and electric circuits (not shown).

The head chassis control mechanism 30 and the tape running direction switching mechanism 31 are driven by cam disks 34 and 35 rotatably arranged by shafts 32 and 33, respectively.
Each cam disk is rotated by a drive gear 37 rotatably arranged on the chassis 1 by a shaft 36. Then, as is clear from FIG. 8, the drive gear 37 has a gear 38 coaxially arranged with the flywheel 4a,
Rotation is transmitted via a gear 39a rotatably arranged on the chassis 1, a gear 39b rotating integrally with the gear 39a, a gear 40a, and a gear 40b rotating integrally with the gear 40a.

The head chassis control mechanism 30 will be described with reference to FIGS. 1 to 7 showing the back surface of the chassis.

A lever 18 for moving the head chassis 14 back and forth is rotatably arranged on the back surface of the chassis 1 by a shaft 17, and an engaging portion 18a at one end thereof is always engaged between the engaging protrusions 143, 144 of the head chassis 14. The engaging pin 18b at the other end is always engaged with a cam portion 342 of the cam board 34 described later, and the head chassis 14 can be moved back and forth by rotating the cam board 34. .

A recording control lever 42 is rotatably attached to the bearing 16b of the capstan 3b, and is always biased counterclockwise by a spring 43. An engaging piece that engages with the free end of the rotating arm 22 is provided at one end of the recording control lever 42.
42a is formed and is always connected by a spring 44 with the engaging piece 42a engaged with the rotating arm 22. When the recording control lever 42 rotates counterclockwise, the rotating arm 22 is spring-loaded. It is designed to be pulled up via 44. Further, by setting the rotation stroke of the recording control lever 42 larger than the stroke of the rotation arm 22, the rotation arm 22 is moved upward by the spring 44 in the recording state in which the recording control lever 42 is rotated counterclockwise. Is urged to. As a result, the erasing head 19a or 19b attached to the rotating arm 22 via the lever 21 is pressed against the engaging portion 202a or 202b of the head guide 20a or 20b by the elasticity of the spring 44, and the erasing head protrudes from the tape T. The amount can be accurately determined.

Further, the recording control lever 42 is formed with an engagement piece 42b engageable with an engagement portion 45c of an actuating plate 45 described later and an engagement portion 42c engaged with an engagement stepped portion 51a of a lock lever 51 described later. ing.

On the other hand, the bearing 16b between the recording control lever 42 and the chassis 1 has a recording control lever 42 depending on the operation mode.
An operating plate 45 that engages and disengages with is disposed so as to be rotatable and movable left and right with a long hole 45a, and is always biased leftward by a spring 46 when viewed in the figure. An engaging portion 45b capable of engaging with the engaging protrusion 144 of the head chassis 14 is formed at the tip of the recording control lever 4 as well.
Engaging pieces 45c engageable with the two engaging protrusions 42b are formed respectively, and an engaging portion 45d engageable with a trigger lever 47, which will be described later, is formed in a substantially central portion.

Below the recording control lever 42 and the operating plate 45 in the drawing, a trigger lever 47 for controlling the cam board 34 is rotatably arranged by a shaft 48, and the cam board 3 is provided at one end thereof.
4. An engaging pin 47a that engages with the cam portions 343, 344 on the upper surface of the upper surface 4 is engaged with a metal plate 47b at the other end so as to be attracted to the electromagnet 50, and an engagement portion 45d of the actuating plate 45 is engaged approximately at the middle. Joint arms 47c are respectively formed and are always biased clockwise by a spring 49.

The electromagnet 50 and the electromagnet 66, which will be described later, used in the tape recorder of the present invention are so-called release electromagnets and have a permanent magnet iron core, and the magnetic force of the permanent magnet is offset by exciting the coil. I am using a type that does. Therefore, for example, when the electromagnet 50 is excited in a state where the metal plate 47b of the trigger lever 47 is attracted to the permanent magnet of the electromagnet 50 as shown in FIG. 1, the magnetic force of the permanent magnet is offset and the trigger lever 47 is replaced by the spring 49. It is rotated clockwise by the elasticity of.

A lock lever 51 for locking the recording control lever 42 in the operating position is provided above the recording control lever 42 in each figure.
Is rotatably attached by a shaft 52 and is biased clockwise by a spring 53. The lock lever 51 has an engaging portion 51a for engaging and locking the engaging portion 42c of the recording control lever 42, and the head chassis 14
Engaging protrusions 51b engageable with the engaging protrusions 145 are formed respectively. Incidentally, 54 is a stopper pin of the lock lever 51.

As is apparent from FIG. 16 together with the cam disk 34, a gear portion 341 is formed on the outer periphery thereof, and the gear portion 341 is formed.
Stop position ST, recording / playback position RP, music selection position M
Tooth lacking portions 341a, 341b, 34 facing the drive gear 37 at S
1c is formed.

On the lower surface of the cam board 34, a cam portion 342 with which the pin 18b of the lever 18 is constantly engaged is formed.
Engaging surfaces 342a, 342b, 342c for controlling movement of 4 to the stop position ST, the recording / reproducing position RP, and the music selection position MS are continuously formed.

The engagement surface 342a has the largest diameter, the engagement surface 342b has the smallest diameter, and the engagement surface 342c has a diameter slightly larger than that of the engagement surface 342b. Has been decided.

That is, the pin 18b of the lever 18 has the largest engagement surface 3
When it is located at 42a, the lever 18 is in the most rotated clockwise position as shown in FIG. 1, and the head chassis 14 is at the stop position ST farthest from the tape T as shown in FIG. It is in. When the pin 18b of the lever 18 is located on the engagement surface 342b having the smallest diameter, the lever 18 is in the most counterclockwise rotation state as shown in FIG. As shown in FIG. 10, the recording / reproducing position RP is advanced so that the head 13 is pressed against the tape T.

Further, when the pin 18b is engaged with the engagement surface 342c, the lever 18 is in a position rotated slightly clockwise as compared with when the pin 18b is engaged with the engagement surface 342b, and as shown in FIG. ,
The head chassis 14 is slightly retracted from the recording / reproducing position RP, and becomes a so-called high-speed music selection position MS where the head 13 is lightly contacted with the tape T.

On the upper surface of the cam board 34, cam portions 343 and 344 engaging with the pin 47a of the trigger lever 47 are formed so as to face each other.

The cam portion 344 on the outer side is for the positioning lock of the cam board 34, and is engaged with the pin 47a of the trigger lever 47 so that the cam board 3 can be held.
Lock projection 34 for stopping, recording / playing, and locking at 4
4a, 344b, 344c are formed.

The inward cam portion 343 is for controlling the trigger lever 47, and the trigger lever 47 that is separated from the electromagnet 50 and unlocks the cam board 34 is rotated counterclockwise to lock the cam portion 344. Engagement protrusions 343a to 343d for returning to positions engageable with the protrusions 344a to 344c are formed, and an engagement slope for converting the pressure contact of the pin 47a of the trigger lever 47 into the starting force of the cam disk 34. 343e is formed.

Looking at the tape running direction switching mechanism 31, as shown in FIGS. 12 to 15, pinch roller levers 10a, 10b, a reel stand drive system (not shown), an electric circuit, etc. are provided on the back surface of the chassis 1 in the tape running direction. The tape running direction switching lever 60 that switches according to the long holes 60a and 60b and the shafts 61 and 33
Is horizontally movably arranged by a spring, and is always biased by a spring 62 to the right as viewed in each drawing.

At the lower edge of the tape running direction switching lever 60, there are engaging slopes 601a, 601b for controlling the pinch rollers 9a, 9b to and from the capstans 3a, 3b by controlling the pinch roller levers 10a, 10b, and the pin of the lever 21. Engaging slopes 602a, 602b for engaging the 211a, 211b to bring the erasing heads 19a, 19b into and out of contact with the tape T are formed.

Therefore, as shown in FIG. 13, when the tape running direction switching lever 60 is moved to the right, the forward side pinch roller lever 10a comes off the engaging slope 601a and the capstan 3a.
The pinch roller 9a is pressed against the pinch roller 9a, and the reverse side pinch roller lever 10b is pushed down by the engaging slope 601b to separate the pinch roller 9b from the capstan 3b. Further, regarding the erasing head, the engagement pin 211b is pushed down by the engagement slope 602b, and the engagement pin 211a is engaged.
By releasing 602a, the lever 21 is rotated counterclockwise, the forward side erasing head 19a is pressed against the tape T, and the reverse side erasing head 19b is separated from the tape T. As a result, the tape forward running state is set.

Further, the tape reverse running state can be performed in exactly the same manner by moving the tape running way switching lever 60 to the left as viewed in the figure, contrary to the above.

In the stopped state shown in FIG. 12, the pinch roller levers on the left and right are clearly shown with reference to FIG. 9 together.
10a and 10b are separated from the capstans 3a and 3b by the engaging portions 141a and 141b of the head chassis 14, and the erasing heads 19a and 19b.
Is also in a position retracted from the tape T and is irrelevant to the tape running direction switching lever 60, and is controlled by the tape running direction switching lever 60 by moving the head chassis 14 and the lever 21 forward in a recording state and a reproducing state. It will be possible. Details will be described later.

On the other hand, a pin 603 is provided on the tape running direction switching lever 60.
Is provided, the pin 603 is engaged in the cam portion 352 on the lower surface of the cam disc 35 for switching the tape traveling direction, and the rotation of the cam disc 35 causes the tape traveling direction switching lever 60 to move laterally. There is.

A gear portion 351 capable of meshing with the drive gear 37 is formed on the outer periphery of the cam disk 35, and the gear portion 351 has toothless portions 351a, 351b facing the drive gear 37 in the forward traveling state and the reverse traveling state. Has been formed. The tape running direction switching lever 60 is attached to the lower surface of the pin 603.
Large diameter part 35 to move to the right position (forward)
2a and a cam portion 352 including a small diameter portion 352b for moving to the left position (reverse) are formed. A cam portion 353 is formed on the upper surface for engaging with a trigger lever 63, which will be described later, to lock the rotational position. The cam portion 353 is locked to the pin 63a of the trigger lever 63 on the inner circumference to form a cam plate. Locking portions 353a and 353b for locking 35 in the forward position and the reverse position, respectively, are formed, and engaging slopes 354a and 354b for converting the pressure contact force of the trigger lever 63 into the rotational force of the cam disk 35 are formed on the outer periphery. A cam portion 354 having a small diameter portion 354c for returning the trigger lever 63 is formed.

The trigger lever 63 is rotatably attached to the chassis 1 by a shaft 64 and is biased counterclockwise by a spring 65, and has a cam portion 353 of the cam board 35 at one end.
Is provided with an engagement pin 63a, and the other end is provided with a metal plate 63b. On the chassis 1 facing the metal plate 63b, a release type electromagnet 66 for attracting and holding the trigger lever 63 against the spring 65 is arranged.

Next, the operation will be described step by step.

(1) Stopped state As shown in FIG. 1, the cam disk 34 is at a position where its toothless portion 341a faces the drive gear 37, and the cam portion 34 on the upper surface is
The locking protrusion 344a of No. 4 is locked to the pin 47a of the trigger lever 47 to hold its position. The position of the trigger lever 47 rotated counterclockwise against the spring 49 is held by being attracted to the permanent magnet of the electromagnet 50.

The pin 18b of the lever 18 for controlling the head chassis is in a position where the maximum diameter portion 342a of the cam portion 342 is engaged, and the lever 18 is rotated clockwise by the spring 67 of the head chassis 14. Is a stop position S at which the head 13 is separated from the tape T as shown in FIG.
It has been set back to T.

The left and right pinch roller levers 10a and 10b are pushed down by the engaging portions 141a and 141b of the head chassis 14, respectively, and are forcibly separated from the capstans 3a and 3b.

The recording control lever 42 is rotated counterclockwise by the spring 43, and the rotation arm 22 is also in a position where the lever 21 is retracted downward as viewed in the figure, and the erasing heads 19a and 19b at both ends of the lever 21 are Both are in the stop position ST separated from the tape T.

In addition, the trigger lever 47 rotates counterclockwise so that the arm
When 47c moves to the left as viewed in FIG. 1, the operating plate 45 is moved to the left by the spring 46, and the engaging portion 45b thereof does not engage with the engaging protrusion 144 of the head chassis 14. It is in.

The lock lever 51 is held by a stopper pin 54 at a position where it is rotated clockwise by a spring 53.

(2) Play state In the stop state described above, the electromagnet 50 is instantly excited only once.

The holding force of the permanent magnet is canceled by the excitation of the electromagnet, and the trigger lever 47 moves the spring 49 as shown in FIG.
Is rotated clockwise by.

This causes the pin 47a of the trigger lever 47 to move the cam board 34
Is separated from the locking protrusion 344a of the cam portion 344 of the
The locked state of 4 is released. At the same time, the pin 47a of the trigger lever 47 is pressed against the engagement slope 343e of the inner cam portion 343, and the cam disk 34 receives a rotation start force in the clockwise direction, meshes with the drive gear 37, and is subsequently rotated by the drive gear 37. To be done.

When the cam plate 34 rotates clockwise, the pin 18b of the lever 18 gradually moves from the large diameter portion 342a of the cam portion 342 to the small diameter portion 3b.
It is rotated counterclockwise by moving to 42b,
With the engaging portion 18a, the head chassis 14 is moved upward as viewed in the figure, that is, in the direction of advancing toward the tape T.

On the other hand, when the cam board 34 rotates to the position shown in FIG. 3, the pin 47a of the trigger lever 47 causes the engagement protrusion 343a of the cam portion 343 to move.
When the trigger lever 47 is rotated counterclockwise against the spring 49 by being pressed in the outer peripheral direction by the permanent magnet of the electromagnet 50, its position is held again (at this time, the electromagnet 50 is not rotated). Excited).

In the above-described operation, when the trigger lever 47 is rotated clockwise, the engaging plate 47c moves the actuating plate 45 to the right against the spring 46, and the engaging portion 45b is temporarily moved. Is brought to a position opposed to the engaging protrusion 144 of FIG. 1, but the trigger lever 47 is rotated counterclockwise by the engaging protrusion 343a of the cam portion 343, and the spring force of the spring 46 causes the spring lever 46 to return to the left. When the head chassis 14 moves forward, the engaging portion 45b is controlled so as not to engage with the engaging protrusion 144 of the head chassis 14. That is, even if the head chassis 14 moves forward, the operating plate 4
5 does not operate, and the rotating arm 22 that controls the erasing heads 19a and 19b does not move from the stop position.

After that, when the cam plate 34 continues to rotate and the pin 18b of the lever 18 moves to the small diameter portion 342b of the cam portion 342 as shown in FIG. 4, the head chassis 14 becomes as shown in FIG.
The recording / playback position RP where the head 13 is pressed against the tape T is reached.

By moving the head chassis 14 forward, a pinch roller lever
10a and 10b became free, and the tape running direction switching lever 6
The engagement slopes 601a and 601b of 0 can be switched to the side depending on the tape running direction.

On the other hand, as shown in FIG. 4, the drive gear 37 has a toothless portion 341b.
Are opposed to each other, the rotation transmission to the cam board 34 is cut off, and at the same time, the pin 47a of the trigger lever 47 moves the cam portion 3
The position of the cam disk 34 is locked by engaging with the locking portion 344b of the cam 44.

In addition, the small diameter portion 342b of the cam portion 342, which is in pressure contact with the pin 18b of the lever 18, is formed with an inclined surface.
The pressing force of 18b acts as a starting force for rotating the cam board 34 clockwise.

(3) Recording State The recording operation is performed by exciting the electromagnet 50 similarly to the play operation, but the play operation and the recording operation can be selected by the excitation timing of the electromagnet.

The operation of the head chassis 14 is exactly the same as that of the play operation. By exciting the electromagnet 50, the cam disk 34 is unlocked and engaged with the drive gear 37. Thereafter, the head disk 14 is moved forward by the rotation of the cam disk 34. However, during the recording operation, as shown in FIG. 3, the cam disk 34 is rotated to a position where the trigger lever 47 is rotated counterclockwise by the engaging projection 343a of the cam portion 343. By the way, the electromagnet 50 is excited again (cam board 3
4 It may be kept excited from the start). Then, the trigger lever 47 returns to the position where it was once attracted to the electromagnet 50 by the engaging protrusion 343a, but since the electromagnet is excited, the spring is re-energized when the engaging protrusion 343a is released as shown in FIG. It is rotated clockwise by 49.

When the trigger lever 47 rotates, its engaging arm 47
c presses the engaging portion 45d of the operating plate 45 to the right, and the operating plate 4
5 is moved to the right against the spring 46. The engaging portion 45b of the operating plate 45 is engaged with the engaging protrusion 1 of the head chassis 14.
It becomes a position where it can be engaged with 44. Even if the operating plate 45 moves to the right, the engagement piece 45c is in a position where it can be engaged with the engagement protrusion 42b of the recording control lever 42.

Therefore, when the cam disk 34 continues to rotate in the clockwise direction and the head chassis 14 moves forward by the lever 18, the operating plate 45 is rotated in the clockwise direction by the engaging protrusion 144 of the head chassis 14, and the engaging piece 45c is used. The engagement protrusion 42b of the recording control lever 42 is pressed, and this is rotated clockwise.

The recording control lever 42 is rotated by the spring 44 to rotate the arm 22.
Since the recording control lever 42 is rotated, the rotating arm 22 is rotated counterclockwise as viewed in the figure, and the lever 21 is moved forward to the tape T, depending on the tape running direction. Side erasing head (forward erasing head 19a in the figure) is the head guide 20a on the head chassis 14.
In accordance with the above, the tape T is pressed and brought into the recording state shown in FIG. Further, since the rotation stroke of the recording control lever 42 is set to be larger than the rotation stroke of the rotating arm 22, the recording control lever 42 separates the engaging portion 42a from the rotating arm 22 in the recording state to rotate it. The moving arm 22 is biased upward by a spring 44 as viewed in the figure. As a result, the erasing head 19a is moved to the head chassis 14
With the upper head guide 20a, it advances to the tape T and is pressed against the engaging portion 202a of the head guide 20a by the elastic force of the spring 44 so that the tape T is positioned.

When the cam disk 34 continues to rotate and the head chassis 14 is brought to the recording / reproducing position, as shown in FIG. 6, the cam disk 34 has the toothless portion 341b in the drive gear 3 as in the play operation.
Stop with 7 facing. The trigger lever 47 is provided with a cam portion 34 immediately before the cam board 34 reaches the recording / playback position.
It is rotated counterclockwise by the engagement projection 343b of No. 3.
At this time, the electromagnet 50 is already in a non-excited state,
The rotation position of the trigger lever 47 is held by the permanent magnet of the electromagnet 50, and the pin 47a is located at a position facing the locking protrusion 344b of the cam portion 344. Therefore, the cam board 3
4 is held in the same rotational position as in the play operation.

The recording control lever 42 is locked at its rotation position by the engagement portion 42c of the recording control lever 42 engaging with the engagement portion 51a of the lock lever 51.
The forward position where the tape T of 19a or 19b is pressed against the tape T is locked, and the recording state is maintained.

The lock lever 51 is pressed by the engagement protrusion 145 on the side surface of the head chassis while the head chassis 14 is moving forward,
Although the head chassis 14 is once rotated counterclockwise, when the head chassis 14 is advanced to the recording / reproducing position, it is brought to the position rotated clockwise by the spring 53 again, and the recording control lever 42 is surely moved. Locked.

(4) Reversing operation of tape running direction In the recording and reproducing states described above, the tape running direction can be reversed by exciting the electromagnet 66.

FIG. 13 shows a tape-forward recording state, in which the toothed portion 351a of the cam disk 35 faces the drive gear 37, and the locking portion 353a of the cam portion 353 is the trigger lever 63.
The position is held by being locked by the pin 63a.

The tape running direction switching lever 60 has its pin 603 located at the large diameter portion 352a of the cam portion 352, and is in the state of being moved to the right as seen in the figure. Therefore, the pinch roller 9b and the erasing head 19b on the reverse side are engaged with the inclined slope 6 respectively.
The tape T is retracted by 01b and 602b, and the forward side pinch roller 9a and the erasing head 19a are pressed against the capstan 3a and the tape T, respectively, to be in the forward recording state. The tape running direction switching lever 60
Needless to say, the reel base drive system, electric circuit, and the like (not shown) are also switched to the forward traveling side.

When the electromagnet 66 is excited in this state, as shown in FIG. 14, the trigger lever 63 is rotated counterclockwise by the spring 65, and the engagement pin 63a thereof is locked by the engagement portion 3 of the cam portion 353.
It is pressed against 54a. As a result, a clockwise rotation starting force is applied to the cam board 35, and the cam board 35 is brought into mesh with the drive gear 37 as shown in FIG.

When the cam board 35 rotates, the tape running direction switching lever 6
In 0, the pin 603 moves from the large diameter portion 352a of the cam portion 352 to the small diameter portion 352b, and moves leftward against the spring 62. As a result, the forward side pinch roller 9a and the erasing head 19a are separated from the tape T by the engaging slopes 601a and 602a, respectively, and the reverse side pinch roller 9b and the erasing head 19b are pressed against the capstan 3b and the tape T, and at the same time. The reel stand drive system and electric circuit (not shown) are also switched, and a reverse recording state is set.

The cam disk 35 is located at a position where the toothless portion 351b faces the drive gear 37. Immediately before that, the pin 63a of the trigger lever 63 is returned to be rotated clockwise by the small diameter portion 354c of the cam portion 354 and is held by the electromagnet 66 again, and the cam board 35 is engaged with the cam portion 353. The position of the stopper 353b is maintained by being locked by the engagement pin 63a of the trigger lever 63.

After that, the electromagnet 66 is momentarily excited to rotate the trigger lever 63, thereby rotating the cam board 35 and reversing the tape running direction.

(5) Music selection operation A music selection state can be obtained by exciting the electromagnet 50 in the recording or playing state.

For example, when the electromagnet 50 is excited in the recording state shown in FIGS. 6 and 10, the trigger lever 47 is rotated clockwise by the spring 49, and the engagement pin 47a thereof is separated from the locking portion 344b of the cam portion 344. Then, the lock of the cam board 34 is released.

The cam disk 34 is rotated clockwise by the pressure contact force between the slope of the small diameter portion 342b of the cam portion 342 and the lever 18b, and is brought into mesh with the drive gear 37.

The cam disk 34 is rotated to a position where the toothless portion 341c faces the drive gear 37, and the pin 18b of the lever 18 moves to the music selection position 342c where the diameter is slightly larger than the small diameter portion 342b of the cam portion 342. At this time, the trigger lever 47 is rotated counterclockwise by the pin 47a thereof being pressed by the cam portion 343c, and is held by the electromagnet 50.
As shown in FIG. 7, the cam disk 34 is held at this position by the locking portion 344c of the cam portion 344 being locked by the pin 47a of the trigger lever 47.

This causes lever 18 to rotate slightly clockwise,
As shown in FIG. 11, the head chassis 14 has a tape T
The head 13 is moved back to the music selection position where the head 13 is lightly touched.
When the head chassis 14 is retracted, the pinch roller 9a is separated from the capstan 3a by the engaging portion 141a, and the engaging portion 51b of the lock lever 51 is pushed leftward by the engaging portion 145 of the head chassis 14. Is rotated counterclockwise, and the locked state of the recording control lever 42 is released.

Therefore, the recording control lever 42 is returned counterclockwise by the spring 43, and the rotary arm 22 is also returned to the stop position retracted from the tape T. The operating plate 45 is also moved to the left by the elastic force of the spring 46, and the engaging portion 45b of the operating plate 45 returns to the original position where it does not face the protrusion 144 of the head chassis 14.

By the above operation, the recording state is released, the tape recorder becomes a state in which music can be selected as shown in FIGS. 7 and 11, and the reel base drive system (not shown) is set to the high speed transfer mode,
By detecting a non-recording portion on the tape T by a well-known inter-track detecting circuit, it is possible to find the beginning of the music recorded on the tape.

The tuned position 342c of the cam portion 342 is also formed with an inclined surface for converting the pressure contact force of the pin 18b of the lever 18 into the rotational force in the clockwise direction, so that the cam disk 34 is biased clockwise. Is held in.

In the above-described music selection state, when a music interval on the tape T is found, or when the music selection operation is stopped, the electromagnet 50 is excited to rotate the trigger lever 47 clockwise.
The lock of the cam board 34 is released.

The cam plate 34 is meshed with the drive gear 37 by the pressure contact force of the pin 18b of the lever 18, so that the toothless portion 341a has the drive gear 37.
When it is rotated to a position facing the position, the engaging portion 344a of the cam portion 344 is stopped by the pin 47a of the trigger lever 47 that has been returned to the outside by the engaging protrusion 343d of the cam portion 343, and stops. It returns to the stopped state shown in Fig. 1.

If the electromagnet 50 is excited again (or the electromagnet 5
If 0 is left excited, the play state can be established as described above, and the play state can be established following the music selection operation.

It should be noted that when the operation is shifted from the play state to the music selection operation, the operation for canceling the recording is not necessary and the operation is exactly the same as the above-mentioned operation, and therefore the description thereof will be omitted.

As described above, the operation mode switching mechanism of the present invention can control four operation modes of recording, reproduction, song selection, and stop by one cam board 34, and the cam board 34 can be located at a position corresponding to each mode. Whether or not to stop is controlled by the excitation timing or the excitation time of the electromagnet 50. Therefore, when the cam board 34 moves from the recording or playback position to the music selection position, the electromagnet 50 is excited or the previous operation mode is released. If the excitation state is maintained from that time, the rotation of the cam board 34 can be controlled to the stop position without stopping. Further, if the cam disk 34 is rotated from the stopped state and the electromagnet 50 is excited or excited when the cam disk 34 reaches the recording / reproducing position, the next music selection state can be directly established, and the excitation timing of the electromagnet 50 or By controlling the excitation time, switching patterns of all operation modes are possible.

(Effects of the Invention) As described above, according to the operation mode switching mechanism of the present invention, the magnetic head for recording / reproducing is provided and the stop position and the recording / reproducing with the magnetic head pressed against the magnetic tape are possible. A head chassis movably arranged between a recording / playback position, a drive gear rotated by a motor, a cam disk rotated by the drive gear to control the movement of the head chassis to each position, and the cam. A trigger lever that locks a rotational position corresponding to each moving position of the head chassis of the board, an electromagnet that controls the trigger lever, an erase head lever that mounts an erase head, and a recording mode setting controlled by the trigger lever. And an operating plate for controlling the erasing head lever by engaging with the head chassis, and the electromagnet is set in a reproduction mode setting or a recording mode. By changing the excitation mode according to the setting, the movement path of the trigger lever with respect to the cam board is changed, and when the recording mode is set, the operating plate is engaged with the head chassis via the trigger lever and the operating plate is moved. Since the erasing head lever for mounting the erasing head is controlled via the above, the mechanism of the control system of the head chassis can be effectively used, and the effect is great.

[Brief description of drawings]

Each drawing shows an embodiment of the present invention, and is shown in FIG.
FIG. 7 is a plan view of the head chassis control mechanism as seen from the back side. FIG. 1 is a stopped state, FIGS. 2 and 3 are states in the middle of transition from the stopped state to a recording or playback state, and FIG. Is a play state, FIG. 5 is a state showing the moment when the recording operation is started, FIG. 6 is a recording state, and FIG. 7 is a music selection state. FIG. 8 is a plan view showing the structure of the back surface of the tape recorder. 9 to 11 are plan views seen from the front side of the tape recorder. FIG. 9 shows a stopped state, FIG. 10 shows a forward recording state, and FIG. 11 shows a music selection state. First
2 to 15 are plan views seen from the back side of the tape running direction switching mechanism. FIG. 12 shows a stopped state (the tape running direction is the forward side), FIG. 13 shows a forward recording state, and FIG.
The figures respectively show states in the middle of switching the tape running direction from the forward direction to the reverse direction. FIG. 16 is a plan view of the cam board 34. Explanation of symbols 1 …… Chassis, 3a, 3b …… Capstan 10a, 10b …… Pinch roller lever 14 …… Head chassis, 143-145 …… Engagement protrusion 18 …… Lever, 19a, 19b …… Erase head 21 ...... Lever, 22 …… Rotating arm 30 …… Head chassis control mechanism 31 …… Tape running direction control mechanism, 34,35 …… Cam board 37 …… Drive gear, 42 …… Recording control lever 45 …… Operating plate , 47, 63 …… Trigger lever 50, 66 …… Electromagnet, 51 …… Lock lever 60 …… Tape running direction switching lever

Claims (1)

[Scope of utility model registration request] 1. A head chassis provided with a magnetic head for recording / reproducing and movably arranged between a stop position and a recording / reproducing position capable of recording / reproducing with the magnetic head pressed against a magnetic tape. A drive gear rotated by a motor, a cam disc rotated by the drive gear to control the movement of the head chassis to the respective positions, and a rotational position of the cam disc corresponding to each movement position of the head chassis are locked. A trigger lever, an electromagnet that controls the trigger lever, an erase head lever that mounts an erase head, and an operating plate that is controlled by the trigger lever and engages with the head chassis when recording mode is set to control the erase head lever. And by changing the excitation mode of the electromagnet in accordance with the reproduction mode setting or the recording mode setting, The movement paths of the rigger lever with respect to the cam board are made different, and when the recording mode is set, the operating plate is engaged with the head chassis via the trigger lever and the erasing head lever for mounting the erasing head is controlled via the operating plate. An operation mode switching mechanism for a tape recorder, which is characterized in that