JPS5826096B2 - Tape recorder drive mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects the end of the tape or the stoppage of tape running after removing slack in the tape, and moves to the next operation in a tape recorder, especially a small cassette tape recorder such as a car stereo. The invention relates to a drive mechanism for

Conventional tape end detection devices detect when the tape is running in one direction and the reel stand stops rotating when the entire tape is wound up, and move on to the next operation, for example, stop the drive source. Alternatively, the direction of playback of the tape may be changed.

By the way, in the conventional tape end detection device described above, detection is possible when the reel stands are rotating in the same direction, but in order to remove slack in the tape, the end of the reel is detected when each reel stand is rotated in the tape winding direction. In such cases,
Stoppage of the tape after the tape slack was taken up could not be detected and therefore it was not possible to proceed to the next operation.

This invention was developed in view of the above points, and its purpose is to detect when the tape stops running even when the reel stands are rotated in the tape winding direction, and to reel the tape. It is an object of the present invention to provide a drive mechanism for a tape recorder that can stop the rotation of the stand or change the running direction of the tape.

Next, one embodiment of the structure will be described with reference to the drawings.

1 is a chassis, 2 is a motor attached to the chassis 1, 3 and 4 are first and second flywheels, and the lower ends of rotating shafts 3a and 4a are attached to a back plate 5 attached to the back of the chassis The upper parts of the rotating shafts 3a and 4a are supported on resin bearing plates 6 and 7 attached to the chassis 1.

Note that the bearing plates 6. of the rotating shafts 3a and 4a. Since the portion projecting upward from γ serves as a capstan, the rotating shafts 3a and 4a are hereinafter referred to as capstans.

Furthermore, guide rods 6a and 7a are integrally formed on the bearing plates 6 and 7, respectively, to fit into guide holes of the cassette.

Reference numeral 8 denotes a pulley pivotally supported on a base plate for equipping a tape stop detection unit, which will be described later.
A belt 9 is inserted between the pulley 2b fitted on the rotating shaft 2a of the
is wound (see Figure 2).

Therefore, when the motor 2 rotates, the first and second flywheels 3 and 4 and the pulley 8 are rotated.

Gears 3b and 4b are formed on the first and second flywheels 3 and 4, respectively, and connecting gears 10a and 10a provided on the respective gears 3b and 4b and control levers 10 and 11 are connected to each other.
The continuous gears 10a, 1a and the gears 12a, 13 of the first and second reel stands 12.13 are meshed with each other.
a are meshed with each other.

Therefore, when the first and second flywheels rotate 3°4,
The first and second reel stands 12 and 13 each rotate in the direction of winding the tape.

The control levers 10 and 11 have a substantially U-shape, and have an end 10b.
.

11b is pivotally supported by pins 1a and Ib implanted in the chassis 1, and the other end control portion 10C is tensioned with a spring 11e.
, 11C correspond to the head 41a of the selection arm 41, which will be described later.

The connecting gear 10a is located near the control portions 10c and llc.

11a is pivotally supported.

Therefore, when the control levers 10 and 11 are rotated about the pins 1a and 1b, the connecting gears 10a and 11 are
It moves along the outer periphery of the gears 12a, 13a of the second reel stand 12.13, and meshes with and disengages from the gears 3b, 4b of the first and second flywheels 3, 4.

Note that 10d and 'lid are release levers 1B and 19, which will be described later.
When the hinges la and 1b are rotated as fulcrums, the control levers 10 and 11 are engaged with the hinges and thereby move the connecting gears 10a and 1a and the gear 3b.

This is an engagement piece for releasing the engagement with 4b.

14.15 is a release plunger attached to the back of the chassis 1, and a pin 14a is implanted in its suction rod;
15a protrudes from the top surface of the chassis 1 through a long hole.

Reference numerals 16 and 17 designate operating levers with the pins 14a and 15a pivotally supported at one end, and springs 18 and 1 between them and the chassis 1.
9 is installed.

Reference numerals 20 and 21 are release levers whose one end is pivotally supported by the operating lever 16 and the other end, and whose approximate center is the chassis 1 mentioned above.
It is pivotally supported by pins 1a and 'Ib.

Reference numeral 22 designates a lock plate that is pivotally supported by a pin 1c implanted in the chassis 1, and has an upright piece 22a formed corresponding to the other end abutting piece of the release levers 20, 21, and a head stand 24, which will be described later. A lock piece 22b is formed to be engaged with a roller 24c attached to the roller 24c.

Note that this lock plate 22 is always given a clockwise rotational force by a spring 23.

Reference numeral 24 has a guide groove 24a in which a pin 1d embedded in the chassis 1 is guided, and a pin 24b guided in the guide groove bored in the chassis 1. This makes the head stand move in parallel. A reproducing head 25 is attached.

Note that in the case of a tape recorder having a recording function, the playback head 25 is used as a recording head, or a recording head is separately provided and an erasing head is attached to the head stand 24.

Further, a roller 24C is provided at the tip of the head stand 24, and when the head stand 24 moves forward, the lock plate 24C
The second lock piece 22b is engaged with the second lock piece 22b.

26.27 is a pinch roller unit, and the support frame 26
pins 1e and 1f with pins 1e and 27a implanted in chassis 1
This support frame 26a is pivotally supported by the support frame 26a.

Pinch rollers 26b, 27b are rotatably attached to 27a, respectively, and rollers 26c, 27 extend downward.
c is attached, and the above-mentioned pin 1e.

Wrapped springs 26d and 27d are provided which are wound around 1f and have both ends engaged with support frames 26a and 27a.

Note that one end of these coiled springs 26d and 27d is attached to the head stand 2.
24d of standing pieces formed at both ends of 40.

It corresponds to 24e.

Also, the roller 26c. 27c is a notch 24f formed in the head stand 24.

I'm facing 24g.

Reference numeral 28 denotes a selection plunger attached to the chassis 1, which serves to select the forward movement of the head stand and the running direction of the tape.

Reference numeral 29 is a lever for advancing the head stand which is pivotally supported by a pin 1g planted on the back surface of the chassis 1, and is formed in a substantially dogleg shape, and one end of which has a fork 29b that is connected to the pin 24b of the head stand 24. A pin 29a is implanted at the other end.

Reference numeral 30 designates a control plate having an engaging pawl 30a pivotally supported by the pin 29a, and a clockwise rotational force is constantly applied by a coil spring 31 provided on the pin 29a to the lever 29 for advancing the head base. Formed upright piece 29c
is in contact with.

A spring 32 is stretched between the other end of the forward lever 29 and the chassis 1, and applies a counterclockwise rotational force to the lever 29.

When the head stand 24 is retracted and the forward lever 29 is rotated counterclockwise, the control plate 30 has an engaging pawl 30a engaged with a pin 28a implanted in the selection plunger 28. Furthermore, when the head stand 24 is moving forward, it is retracted to a position away from the movement trajectory of the pin 28a.

Reference numeral 33 designates a rotary lever that is pivotally supported by a pin 1h implanted in the chassis 1, and one end of which is connected to the pin 28 of the selection plunger 28.
It is pivoted on a.

A rotating arm 34 is pivotally supported by a pin 11 implanted in the chassis 1, has a pin 34a implanted at one end, and extends to the back surface of the chassis 1.

Note that when the head stand 24 is retracted, the rotating arm 34 is moved by the upright pieces 24d and 24f provided on the head stand 24.
and is in a horizontal state.

Reference numeral 35 designates a swinging lever in which a pin 34a of the swinging arm 34 is passed through an elongated hole 35a, and a pin 35b implanted at one end is pivotally supported by the other end of the swinging lever 33.

Further, the other end of this swing lever 35 has two engaging claws 35c.
, 35d are formed.

Reference numeral 36 designates a control arm that is pivotally supported by a pin 1j implanted in the chassis 1, and one end of a spring wire 37 is wound around the implanted pin 36a, and the approximately middle portion extends through the hole of the upright piece 36b. The distal end thereof is inserted between two protrusions 34b formed on the rotating arm 34.

Further, the control arm 36 has extending lever engaging rods 36c and 36d planted on the back surface of the chassis 1, and when the head stand 24 is moving forward, the engaging claw 35c of the swing lever 35 is
, 35d are engaged alternately.

38 is a torsion spring for selectively fixing the rotation of the control arm 360 in two positions.

A spring 39 is stretched between the swing lever 34 and the chassis 1 and pulls the lever 34 to the left.

40 is a pin (not shown) planted on the back side of chassis 1
is inserted into the elongated hole 40a and moves in parallel, and an engagement rod 36d provided on the control arm 36 is engaged with a groove 40b at one end of the slide lever.

This slide lever 40 has a stepped portion 4 that comes into contact with the rollers 26c and 27c of the pinch roller units 26 and 27 to control contact and separation with the capstans 3a and 4a.
0c, 40d, and a roller 41 of the selection arm 41, which will be described later.
b, step portion 40e that comes into contact with 41c to control rotation of the selection arm 41;

40f is formed.

Reference numeral 41 denotes a control unit 1 in which the center of the inscription is a grid-shaped selection arm pivoted on the pin 24b of the head stand 24 described above, and the head 41a faces the control levers 10 and 110 described above.
Rollers 41b and 41c are provided at both ends located between 0c and 11c and extending in the lateral direction.

Reference numeral 42 designates a tape stop detection unit mounting plate, and on its lower surface are the above-mentioned pulley 8, a large gear 43 that meshes with the gear 8a formed on the pulley 8, and a small gear 43 formed integrally with the dog gear 43. A cam plate 44 having a gear 44a that meshes with the gear 43a provided on its outer periphery is pivotally supported.

A cam groove 44b is formed on the upper surface of this cam plate 44, which is the surface facing the mounting plate 42, and a cam base 44 is formed in the center.
c is formed.

Also, on the bottom surface of the mounting plate 42 is the selection plunger 2 described above.
A switch 45 for energizing the switch 8 is attached, and a switch control lever 46 for controlling opening/closing of the switch 45 is pivotally supported.

One end of the lever 46 faces the switch 45, and the other end is pivotally supported by one end of the pin support lever 47.

An engaging pin 47a facing the cam groove 44b of the cam plate 44 is formed at the other end of the pin support lever 47, and its upper end passes through the guide groove 42a of the mounting plate 42.

48 is a guide rod 48a that is slidable in the guide groove 42a.
A guide pin 48b is pivotally supported in a small hole 42b of the mounting plate 42.

Further, the detection arm 48 is formed with a two-pronged engagement piece 48C, and an engagement pin 47a of the support lever 47 is engaged with this engagement piece 48c.

Reference numeral 49 is a detection lever having a hole 49a drilled in the center and pivotally supported by a pin 48d formed on the upper surface of the guide rod 48a of the detection arm 48, and elongated holes 49b at both ends thereof.

49c is worn.

And this long hole 49b. 49C includes the above-mentioned first and second
Reel stand 12゜130 Slip plate 12 provided on the bottom surface
b.

The protrusion 13b is engaged.

The slip plates 12b and 13b are fitted into the shaft portions 13C of the reel stands 12 and 13 (the same applies to the first reel stand 12 side, so only the second reel stand 13 side will be described with reference to FIG. 7), and It is pressed toward the plate portion 13f via the felt 113e by the spring 'f3d.

Therefore, when no load is applied to the slip plate 13b, the slip plate 13b also rotates together with the reel stand 13, but when a load is applied to the slip plate 13b, it slips and stops rotating.

Note that the slip plate 12b. The protrusions 13b face the holes 42c and 42d of the mounting plate 42.

Reference numeral 50 is a track changeover switch whose contacts are switched in accordance with the rotation of the control arm 36 and which switches the reproduction coil of the head 25, and 51 is a track changeover switch whose contacts are switched by the lever 29 for advancing the head stand when the head stand 24 moves forward. 2 is a switch for constant speed rotation, and vice versa for high speed rotation.

The structure has been described above, and the operation will now be described.

When the cassette is not loaded, the head stand 24 is retracted, so the selection arm 41 is also retracted, and the control section 10C211c of the control levers 10, 11 is
It is not displaced by a.

Therefore, the connecting gear 10a is the gear 3 of the first flywheel 3.
a and the gear 12a of the first reel stand 12, and the connection gear 11F& connects the gear 4a of the second flywheel 4 and the gear 13a of the second reel stand 13.

When a cassette (not shown) is loaded in this state,
The motor 2 is energized by a power switch (not shown).

At this point, since the head stand 24 is retracted, the motor 2 is rotated at high speed in the direction of the arrow in FIG. 2 by the contact of the switch 51.

Therefore, both the first and second reel stands 12 and 13 are rotated in the tape winding direction, and if there is slack in the tape, this slack is removed.

Also, when the reel stand 12° 13 is rotated, the slip plate 12
b and 13b are also rotated in the same direction, so that the detection lever 49 moves upward as shown in FIG.

When the guide rod 48a of the detection arm 48 moves within the guide groove 2a as the detection lever 49 moves, the detection arm 48 is rotated about the guide pin 48b, so that the engagement piece 48C is rotated in the right direction. Displaced to.

This displaced engagement piece 48cK is engaged with the engagement pin 47a of the support lever 47, so the cam groove 48cK of the cam plate 44 is engaged with the engagement pin 47a of the support lever 47.
The lower end of the engagement pin 47a facing the cam groove 4b
It is pressed against the inner circumferential wall of 4b.

Therefore, even if the cam plate 44 is rotated by the pulley 8, the engagement pin 47a does not come into contact with the engagement portion 44d of the cam base 44c, and the engagement pin 47a maintains a state along the inner circumferential wall.

When the slack in the tape is removed, the rotation of the reel shafts 12c and 13c of the reel stands 12 and 13 is stopped by the friction between them and the slip plate 12b.
, the rotational force of 13b disappears.

Note that since the reel stand 12.13 is in a slipping state with the reel shaft portion 12C213c, it continues to rotate.

On the other hand, since the cam plate 44 is constantly rotated by the pulley 8, the engagement pin 47a is moved toward the center by the inner circumferential wall of the cam groove 44b and maintained in that state.

Since the engaging portion 44d of the cam base 44c is located on the trajectory of the moved engaging pin 47a, the engaging pin 47a
a is pushed by the engaging portion 44d.

Therefore, the switch control lever 46 is rotated and the switch 4
Close 5.

Since this switch 45 is connected to the selection plunger 28, the plunger 28 is energized.

When the plunger 28 is energized and the suction rod is pulled, the pin 28a and the engaging claw 30a of the control plate 30 are engaged, so the control plate 30 is pulled and the head base advance lever 29 is moved clockwise. Rotated.

Since the guide pin 24b of the head stand 24 is engaged with the bifurcated portion 29b of this lever 29, the head stand 24 moves forward, and the roller 24c provided at the tip engages with the lock piece 22b of the lock plate 22. will be combined.

Therefore, even after the selection plunger 28 is de-energized and the suction rod returns, the head stand 24 is fixed at the forward position.

Note that when the head base advancement lever 29 is rotated, the control plate 30 is rotated toward the upright piece 29c by the coiled spring 31, so the engaging claw 30a leaves the trajectory of the pin 28a of the plunger 28.

Therefore, when the head stand 24 is moving forward, the plunger 2
Even if the pin 28a is energized again, the pin 28a and the engaging claw 30a will not be engaged with each other.

On the other hand, when the head stand 24 moves forward, the pinch roller unit 2
When the engagement between the rollers 26c and 27c of 6 and 27 and the notches 24f and 24g of the head stand 24 is disengaged, the coiled spring 26d starts moving forward.

When one end of the pinch roller unit 27d is pushed by the upright pieces 24d and 24e, the respective pinch roller units 26 and 27 are rotated toward the capstans 3a and 4a by spring force.

Here, if the slide lever 40 is moving to the right as shown in FIGS. 5 and 10, the roller 26C of the Vinci roller unit 26 is at the step 40c of the slide lever 40, and the roller 41b of the selection arm 41 is at the step. 40e, the rotation of the pinch roller unit 26 is stopped midway, and the pinch roller 26b does not come into contact with the capstan 3a.

Further, the selection arm 41 is rotated counterclockwise to
a contacts the control portion 10c of the control lever 100 and moves it, so that the connection gear 10a and the gear 3 of the first flywheel 3
Remove the mesh with b.

On the other hand, since the roller 27c on the side of the pinch roller unit 27 is located at a position removed from the stepped portion 40d of the slide lever 40, the rotation of the pinch roller unit 27 is not prevented, and therefore the pinch roller 27b is pressed against the capstan 4a. .

Further, since the head 41a of the selection arm 41 and the control portion 11C of the control lever 110 do not come into contact with each other, the gear 4b of the second flywheel 4 and the second reel stand 13 are connected to each other by the connecting gear 11a.
continues to be connected to gear 13a.

Further, since the head stand advancement lever 29 switches the switch 51, the motor 2 rotates at a constant speed.

As a result, the head 25 comes into contact with the tape, the second reel stand 13 begins to rotate in the direction of winding the tape, and the tape is pinched between the capstan 4a and the pinch roller 27b, thus starting reproduction.

Next, a case will be described in which the playback progresses and the tape reaches its end.

If the tape is now wound on the second reel stand 13 side,
The slip plate 13b of the second reel stand 13 applies a clockwise turning force to the detection lever 49, and the slip plate 12b of the first reel stand 12 also applies a clockwise turning force.

Therefore, the detection arm 48 is rotated clockwise, and the engagement pin 47a of the pin support lever 47 is moved into the cam groove 44b of the cam plate 44.
It maintains a state along the inner circumferential wall of the cam base and is not engaged with the engaging portion 44d of the cam base 44C.

Now the running of the tape has stopped and the first and second reel stands 12
．． When the reel shaft portions 12c and 13c of the reel stands 12 and 13 stop, the switch 45 is closed and the selection plunger 28 is closed in the same manner as when the reel shaft portions 12c and 13c of the reel stands 12 and 13 are stopped after removing the tape slack described above. Turn on electricity.

When the plunger 28 is energized and the suction rod is pulled, the rotating lever 33 is rotated clockwise.

Note that since the head stand 24 of the control plate 30 is moving forward, the engaging claw 30a is retracted from the locus of the pin 28a, so the head stand advancement lever 29 is not rotated.

Here, the slide lever 40 is moving to the right, and the control arm 36 with the engaging rod 36d engaged with the groove 40b of the slide lever 40 is rotated counterclockwise. The movable arm 34 is rotated clockwise.

The swing lever 35, in which the pin 34a of the swing arm 34 is inserted into the elongated hole 35a, is rotated clockwise, and the engagement claw 35d is engaged with the engagement rod 36d of the control arm 36.

Therefore, when the rotation lever 33 is rotated clockwise and the swing lever 35 is pulled, the control arm 36 is rotated clockwise.

As a result, the slide lever 40 moves to the left as shown in FIG. 11, the roller 27d of the pinch roller unit 27 rides on the stepped portion 40d, and the roller 41c of the selection arm 41 rides on the stepped portion 40f.

Therefore, the pinch roller 27b is separated from the capstan 4a, and the control lever 110 control section 11c is moved away from the selection arm 41.
is rotated clockwise and pushed by the head 41a, the connecting gear 11a is separated from the gear 4b of the second flywheel 4, and the rotational force to the second reel stand 13 is eliminated.

On the other hand, the roller 26d of the pinch roller unit 26
0c, the pinch roller 26b is pressed against the capstan 3a, and since the head 41a of the selection arm 41 is separated from the control portion 10c of the control lever 100, the connecting gear 10a is connected to the gear 3b of the first flywheel 3 and the first It is connected to the gear 12a of the reel stand 12.

This causes the tape to start running in the opposite direction, and the rotation of the control arm 360 switches the contacts of the switch 50 to switch the head 250 channel, so that tracks in the opposite direction are reproduced.

By the way, in the above state, the control arm 36 is rotated clockwise and the rotation arm 34 is rotated counterclockwise by the spring wire 37, so the swing lever 35 is rotated counterclockwise. Thus, the engaging claw 35c is held in a state where it can be engaged with the engaging rod 36c of the control arm 36.

Therefore, when the playback is finished again and the stop of tape running is detected by the same operation as described above and the selection plunger 28 is energized, the swing lever 35 rotates the control arm 36 counterclockwise and moves the slide lever 40. Pull it to the right, so
The above-mentioned initial state is reached and playback in the original direction is started.

If you want to change the playback channel during playback, close the switch using a replay button (not shown), energize the selection plunger 28, and switch the playback channel in the opposite direction in the same way as the above-mentioned operation after detecting the end of the tape. Playback becomes possible.

Next, a case will be described in which rewinding is performed during playback shown in FIG. 10, that is, during playback when the tape is being wound rightward.

When you press the rewind button (not shown) and close the switch,
The release plunger 15 is energized and its suction rod is pulled.

As a result, the operating lever 17 is pulled against the spring force of the spring 19, and the release lever 21 is rotated counterclockwise.
The tip of the spring 2
It rotates counterclockwise against the spring force of 3.

Therefore, the lock piece 22b and the roller 24C of the head stand 24 are unlocked, and the head stand moves backward by the spring force of the spring 32 via the lever 29 for advancing the head stand.

Further, since the release lever 21 is rotated counterclockwise, the engagement piece 11d of the control lever 11 is engaged with the release lever 21 and rotated, and the connecting gear 11a is separated from the gear 4b of the second flywheel 4, and the engagement piece 11d of the control lever 11 is engaged with and rotated. The 2-reel stand 13 becomes free.

On the other hand, the control portion 10c of the control lever 100 is no longer restricted by the head 41a of the selection arm 41, which retreats as the head stand 24 retreats, so it returns to its original position by the spring force of the spring lle, and the connecting gear 10a moves to the first position. The gear 3b of the flywheel 3 and the gear 12a of the first reel stand 12 are connected.

Further, the head stand 24 is moved backward, the head stand advance lever 29 switches the switch 51, and the motor 2 rotates at high speed.

Therefore, the first reel stand 12 rotates at high speed and winds up the tape.

When the rewinding of the tape is completed and the end of the tape is reached, the switch 45 is closed by an operation similar to the operation after detecting the end of the tape described above, and the selection plunger 28 is energized, and the release plunger 15 is de-energized. Then, the head stand 24 advances again to perform reproduction, but at this time, reproduction is performed in the direction that was being performed before rewinding.

This allows the rotating arm 34 to move when the head stand 24 is retracted.
The upright pieces 24d and 24f keep the swinging lever 3 in a horizontal state.
5 is in a horizontal state so that the engaging claws 35c and 35d do not engage with any of the engaging rods 36c and 36d of the control arm 36.

Further, when returning to playback during rewinding, the power to the release plunger 15 is cut off by operating a replay button (not shown) or the like.

As a result, the operating lever 17 is returned by the spring 19 and the release lever 21 is returned, so that the control lever 11
returns to its original position.

Therefore, the connecting gear 11a is the gear 4 of the second flywheel 4.
b and the gear 13a of the second reel stand 13 are connected, so
The second reel stand 13 rotates in the opposite direction to the first reel stand 12, and if there is slack in the tape, the slack is removed.

When the slack is removed, the head stand 24 moves forward by the same operation as when loading the tape, and reproduction in the reproduction direction before rewinding is performed.

Next, a case will be described in which fast forwarding is performed during playback, that is, during playback when the tape is being wound in the right direction.

When you press the fast forward button (not shown) and close the switch,
After the release plunger 14 is energized and the entire tape is wound in the same way as when rewinding is performed during playback, the first and second reel stands 12 and 13 are moved in the tape winding direction. , and playback in the fast forward direction is started.

However, since the tape is all wound in the fast forward direction, actual playback is not performed and the tape is stopped.

Thereupon, the tape end detection operation is performed, the switch 45 is closed, and the selection plunger 28 is energized, so that the playback progresses and the tape end is reached and playback is performed in the opposite direction by the same operation as described above. Reproduction is started in the reverse direction.

Next, to explain how to eject the cassette, when the eject lever (not shown) is operated, the lock plate 22 is first rotated counterclockwise by the eject lever.

After unlocking the head stand 24, the cassette is ejected and the power is turned off, ending the entire operation.

In the above embodiment, the power switch is turned on when the cassette is loaded.
The power switch can also be set separately and manually.

In addition, in order to remove tape slack, the first and second reel stands 1
2 and 13 in the winding direction, detecting that the tape slack has been removed and the rotation of the reel shaft portions 12c and 13c has stopped, the selection plunger 28 is energized to perform playback. This may be done by energizing the selection plunger 28 for a fixed period of time after loading the tape, or by detecting the tension of the tape.

Further, in the above embodiment, the connecting gear 10a is used from the beginning.

1'la, the first and second flywheels 3, 4, gears 3b, 4b and the gears 12a, 1 of the first and second reel stands
3a is shown, but it is also possible to connect them after the cassette is loaded.

In the above embodiment, when the reel stands 12 and 13 are rotated in the tape winding direction and the slack in the tape is removed,
That is, the reel shafts 12c, 13c rotated by the reel stands 12, 13 when the tape is under tension are stopped by a friction material such as felt provided between the reel stands 12, 13 and the reel shafts 12c, 13c. However, in this case, even if all the tape is wound on one reel stand side, the wound tape should not be wound on the other reel stand side (this condition is the best). If a friction material (having a torque difference) is not provided, it will not be possible to detect tape stop and proceed to the next operation.

1- However, if a dog friction is applied between the two, an unreasonable force will be applied to the tape at the end of the tape, and the tape may be cut.

Therefore, a normal-sized 7-rection is applied between the reel stand and the reel shaft, and when each reel stand tries to rotate from the winding rotation direction to the supply rotation direction only when removing tape slack, the reel on that reel stand It is conceivable that a stopper engages with the shaft portion and prevents it from rotating.

Specific examples thereof will be explained below with reference to FIGS. 13 to 15.

52 and 53 are located approximately at the center 52a of the chassis 1;

53a is an abbreviated ratchet plate to which is pivotally attached, one of which is the plate portion 12f of the reel stands 12, 13.

The plate portion 12f is located on the lower surface of the plate portion 13f and on the upper surface thereof.
, 13g and 12g of engagement protrusions formed on the lower surface of 13f.
Correspondingly, ratchet 52b.

53b is formed.

In addition, Ratchets) 52b. 53b is an engagement protrusion 12g when the reel stands 12, 13 rotate in the tape winding direction;
13g but is not engaged, and the reel stand 12,1
3 rotates in the tape supply direction, the engagement protrusion 12g
, 13g are engaged with the ratchets 52b and 53b, and the plate portions 12f of the reel stands 12 and 13.

It has a shape that prevents rotation of 13f.

Also, an engagement pin 52c is provided at the other end of the ratchet plates 52, 53.
, 53c are formed, and the engagement pins 52c, 5
A spring 54 is provided to apply a force such that the parts 3c are directed outwardly toward each other.

Additionally, ratchet plates 52, 5 provided by springs 54
3 is regulated by stopper pieces 10e and 11e formed on the control levers 10 and 11.

Further, the engaging pins 52c and 53c enter the head stand 24 corresponding to the above-mentioned engaging pins 52c and 53c, and in the latter half of the movement of the head stand 24, the ratchet plate 52.
a guide groove 24h for rotating the ratchet 53 and retracting the ratchets 52b and 53b from the locus of the engagement protrusions 12g and 13g;
24i is formed.

Next, to explain the operation, in FIG. 13, when the head stand 24 is retracted and the reel stands 12 and 13 are rotated in the tape winding direction, the ratchet 52b
, 53b is the engagement protrusion 12g.

Since it is located on the rotation trajectory of 13g, the ratchet) 52
b, 53b and the engaging protrusions 12g, 13g are in contact with each other, but due to their shapes, the ratchet plates 52 and 53 are in contact with the spring 54.
The ratchets 52b and 53 are rotated against the spring force of the ratchets 52b and 53.
b moves from the trajectory of the engaging protrusions 12g and 13g.

Therefore, the plate portions 12f and 13f of the reel stand 12.degree. 13 continue to rotate (see the side of the reel stand 13 in FIG. 3).

Next, the slack in the tape is removed, and for example, if the amount of winding on the reel stand 13 side is small, the tape is removed from the reel stand 13.
Since it moves to the side, the reel stand 12 side becomes the supply side.

Therefore, the locking protrusion 12g comes into contact with the ratchet 52bK and is engaged due to its shape, so a force is applied to rotate the ratchet plate 52 clockwise, but the ratchet plate 52 is prevented from rotating by the stopper piece 10e. As a result, rotation of the plate portion 12f of the reel stand 12 is prevented (reel stand 1 in FIG. 13).
(See side 2).

As a result, the above-mentioned tape end detection device is activated and a transition is made to the playback state.

When the playback state is entered, the head stand 24 moves forward as shown in FIG. 14, so the engaging pins 52c and 53c of the ratchet plates 52 and 53 move into the guide groove 24h.

24i and this guide groove 24h.

Since the tips of the ratchet plates 24i form an arc that matches the rotation locus of the ratchet plates 52 and 53, the ratchet plates 52 and 53 are rotated against the spring force of the spring 54 in the latter half of the forward movement of the head stand 24, respectively.

Therefore, the ratchets 52b and 53b are the engagement protrusions 12g.

Since it retreats from the trajectory of 13g, the engagement between the two disappears.

Of course, during this regeneration, one of the side splitting levers 10 and 11 (the side of the control lever 11 in the figure) is rotated by the selection arm 41 described above, but this rotation is not hindered by the ratchet plate 53.

Next, to fast forward or rewind in Figure 13,
It is necessary to prevent engagement between one of the ratchets and the engagement protrusion.

For example, if the tape is wound to the right, the control L
/ When the cover 1 is rotated by the selection arm 41, the stopper piece 1'le retreats as shown in FIG. The ratchet 53b is rotated by the spring force, so that the ratchet 53b retreats from the trajectory of the engagement protrusion 13g.

As a result, the rotation of the reel table 13 in the supply direction is not inhibited and the tape is wound up.

Further, since the winding in the opposite direction is similar, a description thereof will be omitted.

As described above, in this invention, when the reel shaft of the reel stand is rotating, a displacement force is applied to the detection lever, and when the reel shaft stops and the displacement force is removed, the detection lever is engaged with the cam means and the detection lever is Since it is forcibly displaced to stop the rotation of the reel stand or change the running direction of the tape, it removes slack in the tape and detects when the tape stops running and moves to the next operating state. It has the following effects:

In addition, since the slip plate that applies rotational force in the direction of rotation of the reel shaft is attached to each reel unit, it is very effective to apply it to a reverse type tape recorder, for example, when a cassette is not loaded. It is also possible to detect when one reel shaft stops, such as when the tape is played back or when the tape runs out.

Furthermore, since one set of detection levers, cam means, and displacement detection means are shared by both reel shafts, the structure is simple.

[Brief explanation of drawings]

Fig. 1 is a plan view of the entire tape recorder, Fig. 2 is a perspective plan view seen from the chassis, Fig. 3 is an exploded perspective view, Fig. 4 is a plan view of the head stand drive part showing the playing state, Fig. 5. 6
The figure is a plan view of the part that changes the running direction of the tape when the head is in an advanced state, Figure 7 is a central vertical sectional view of the reel stand,
, 9 is a perspective plan view of the tape end detection portion, FIG. 10 is a plan view of the leftward playback state, FIG. 11 is a plan view of the rightward playback state, and FIG. 12 is a plan view of the leftward fast forward state. ,
13-15 are plan views of an apparatus for preventing tape movement after tape slack has been removed. 1...Chassis, 2...Motor, 3,
4...First and second flywheels, 10, 11
...Control lever 12, 13...--First
, second reel stand, 14° 15...--release plunger, 16, 17... operating lever, 20, 21
...-Release lever, 22 ... Lock plate, 24 ... Head stand, 26 , 27 ...
...Pinch roller unit, 28-...Plunger for selection, 29...Lever for advancing the head stand, 3
0... Control plate, 33... Rotating lever 34...- Rotating arm, 35...-...
Swing lever, 40... Slide lever -4, 42... Unit mounting plate, 44...
...Cam plate, 45, 50, 536...Control a 41...Selection a43...Large gear, 1...Switch, 46... ...Switch control lever 47...Mountain-
e-support lever, 48...detection arm, 49.
...Detection levers 52, 53...-Ratchet plate.

Claims (1)

[Scope of Claims] 1. A slip plate that is attached to each reel unit and applies rotational force in the rotational direction of the reel shaft, and a slip plate that is engaged with the two slip plates and applies a displacement force when the reel shaft rotates. a rotation detecting means provided therein; a cam means that is not engaged with the rotation detecting means when both of the reel shafts rotate, but is engaged with the rotation detecting means when at least one of the reel shafts is stopped; and the cam. A drive mechanism for a tape recorder comprising a displacement detecting means which is engaged with the rotation detecting means and stops the drive or switches to another operating state when the rotation detecting means is displaced. 2. The rotation detecting means includes a detection lever whose both ends are engaged with the slip plate and which applies a displacement force when the reel shaft rotates, a detection arm pivotally connected to substantially the center shaft of the detection lever, and a detection arm at the tip thereof. A provided engagement pin is engaged with the tip of the detection arm, and when a displacement force is applied to the detection lever, a displacement force is applied to the retaining pin in a certain direction via the detection arm. The cam means includes a cam groove in which the engaging pin faces a cam groove having a cam base, and when the displacement force to the engaging pin is removed, it comes into contact with the cam base and supports the pin. It is a constantly rotating cam plate that moves the lever, and the displacement detection means closes the switch when the pin support lever is moved, or displaces another lever to stop the drive, or enters another operating state. The drive mechanism for a tape recorder according to claim 1, characterized in that it is a switching lever.