JPS5827896B2 - Tape stop detection mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape recorder, and particularly to a tape stop detection mechanism thereof.

As is well known, a tape recorder is provided with a tape stop detection mechanism, for example, for an automatic stop mechanism or an auto-repeat mechanism.

Conventionally, such a tape stop detection mechanism detects the stop of tape running when the rotation of the take-up reel stand has stopped.

However, the conventional tape stop detection mechanism as described above requires a cam, a wheel, etc., has a large number of parts, and has a complicated structure, and therefore has a problem in that it is large in size and is not suitable for miniaturization.

In addition, the tape running stop detection means detects when the reel stand stops rotating, and when the tape is running at a constant speed (during recording or playback)
In addition, stoppage of tape running is detected even when the tape is running at high speed (during fast forwarding or rewinding).

Therefore, in a small tape recorder using a small motor, there is a problem in that the rotational torque of the motor is insufficient and the rotation of the motor stops.

Therefore, in conventional small tape recorders, it is necessary to take measures such as biasing the detection lever so as not to detect tape stop when the tape is running at high speed, making the configuration complicated.

This invention was made in consideration of the above circumstances, and provides an extremely good tape stop detection mechanism that has a small number of parts, has a simple structure, operates accurately, is easy to downsize, and is particularly suitable for micro cassette tape recorders. The purpose is to

Hereinafter, an embodiment in which the present invention is applied to an automatic stop mechanism will be described in detail with reference to the drawings.

In FIG. 1a, reference numeral 11 denotes a flywheel, which is rotated by a motor (not shown) regardless of tape running.

The flywheel 11 includes, for example, a take-up idler 13 (not shown) for transmitting its rotational force to a take-up reel stand 12 provided coaxially with a reel shaft 121 on the tape winding side in the playback and recording state. It is provided so that it can be freely approached and separated in conjunction with the playback operator.

As shown in FIG. 1, this take-up idler 13 includes a first idler 14 and a second idler 15 having a larger diameter than the first idler 14, which are commonly connected to a rotating shaft 16 at a predetermined interval. It is rotatably supported.

Here, FIG. 1 shows the take-up idler 13 viewed from the direction indicated by the arrow ■.

A friction member 17 is interposed between the first and second idlers 14,15.

Further, the first idler 14 is formed into a brim shape on a cylindrical member 141 into which the rotating shaft 16 is inserted.

The first and second idlers 14 and 15 are arranged so that the friction member 17, and are pressed and frictionally engaged.

Note that rubber rings 20 and 21 are attached to the circumferential surfaces of the first and second idlers 14 and 15, respectively.

Here, the lower part of the rotating shaft 16 is fixed to a movable member 22, such as a head chassis, which is movable in the directions indicated by arrows A and B in conjunction with the playback operator.

As the movable member 22 moves, the first and second idlers 14 and 15 move toward and away from the take-up reel stand 12 and the flywheel 11.

Furthermore, a friction plate 23 is provided on the lower surface facing the first idler 14 .

This friction plate 23 has one end rotatably supported on the rotating shaft 16 via a bearing 142 provided at the lower end of the cylindrical member 141, and the other end is supported in a direction orthogonal to the friction plate 23. A pin 24, which is a biasing force member and extends in the direction of the second idler 15, is provided.

Further, this friction plate 23 is connected to the first idler 14 by a spring 25 interposed between the friction plate 23 and the first idler 14.
It is said that he is involved in the relationship.

The friction plate 23, bearing 142, and spring 25 constitute a friction mechanism i that applies a biasing force in one direction to a detection body 29, which will be described later, via a pin 24 that is a biasing force member.

Further, a substantially cylindrical cam member 26 is provided on the upper surface of the second idler 15.

This cam member 26 is formed with an engaging portion 27 that protrudes in a spiral negative direction in the radial direction of the second idler 15 .

Here, as shown in FIG. 1a again, the cam member 26
A detection body 29 having a recess 28 sandwiching the detection body 29 has its base end rotatably connected to one end of an automatic stop mechanism lever 31 by a rotation shaft 30.

This automatic stop mechanism lever 31 is rotatably supported at its center by a rotation shaft 32 provided on the main chassis of a tape recorder (not shown), and at the other end is a locking member that locks a lock plate 33. 34 are provided.

Furthermore, an engaging portion 36 that can engage with the engaging portion 27 is formed at the base of one arm portion 35 of the detection body 29 .

The pin 24 of the friction plate 23 is in contact with the inner surface of the tip end of the arm portion 35 .

Further, the other arm portion 37 of the detection body 29 is connected to the arm portion 3
It protrudes in the same direction and parallel to 5.

The operation of the tape stop detection mechanism configured as described above will be explained.

First, the playback operator is operated to engage the lock plate 33.

Then, the movable member 22 moves and the first and second idlers 14 and 15 come into contact with the take-up reel stand 12 and the flywheel 11 via the rubber rings 20 and 21.

At the same time, the flywheel 11 rotates in the direction shown by arrow C in FIG.
2, and the take-up reel stand 12 is connected to the flywheel 11.
The tape is played back by rotating in the same direction.

At this time, since the first idler 14 rotates in the direction shown by the arrow, the friction plate 23 in engagement with the first idler 14 also receives a biasing force in the same direction.

Therefore, the detection body 29 has the above-mentioned friction plate 23 on its arm portion 35.
Since the pins 24 are in contact with each other, a biasing force is applied in the direction of the arrow.

However, as shown in FIG. 2a, when the other arm 37 of the detection body 29 comes into contact with the circumferential surface of the cam member 26,
The detection body 29 is prevented from rotating in the direction of the arrow.

Therefore, slipping occurs between the first idler 14 and the friction plate 23.

Further, when the state shown in FIG. 2 is reached, the engaging portion 27 of the cam member 26 pushes up the arm portion 37 of the detection body 29, so that the moxibustion body 29 rotates in the direction of the arrow E.

While the take-up reel stand 12 is rotating stably,
Since the first idler 14 always applies a biasing force to the detection body 29 in the direction of the arrow, FIG. 2 a→l) −+
The state shown in a... is repeated, the engaging portion 27 and the engaging portion 36 are not engaged, and stable regeneration is performed.

Assume that the tape reaches the end in the above state and the rotation of the take-up reel stand 12 stops.

Then, the first idler 14 stops rotating, but the flywheel 11 continues to rotate, so the second idler 1
5 is rotating.

That is, the friction member 17 and the first and second idlers 14
．． There is a slippage between 15 and 15.

Therefore, the urging force exerted on the detection body 29 by the pin 24 of the friction plate 23 is no longer applied.

However, since the engaging portion 26 is rotating, FIG.
The detection object 29 is moved to the state shown in b.

When the engaging portion 27 rotates as shown in FIG. 2a, since no urging force is applied to the detection body 29 in the direction of the arrow E, it stops in a state where it is pushed up in the direction of the arrow E.

Therefore, as shown in FIG.
It is moved in the direction shown by arrow F in Figure C.

Therefore, the automatic stop mechanism lever 31 rotates counterclockwise, and the locking plate 33 is released.

Thus, the playback operator returns to its original position, and playback is automatically stopped.

Therefore, the first and second idlers 14.15 provided in the winding idler 13 and the engaging portion 27 interlocked therewith.
Since the stop E of the rotating body, such as the take-up reel stand 12, which is interlocked with the reel shaft 121 is detected by the engaging part 36, there is no need for cams, wheels, etc. as in the conventional case, and the overall shape is small. This makes it easy to unitize.

In addition, since it detects when the take-up reel stand 12 stops and automatically stops it, there is no need to apply large tension to the tape, and the operation is reliable.Also, even if the take-up reel stand 12 stops due to tape entanglement, etc., it will automatically stop. will be done.

In addition, since the engagement portion 27 and the engagement portion 36 are engaged with each other in the direction of rotation of the second idler 15, a large release force of the lock plate 33 can be obtained.

Furthermore, since the take-up idler 13 used for playback or recording is provided with a tape running stop detection mechanism, the take-up idler 13 engages with the take-up reel stand 12 when rewinding, that is, when the reel shaft 121 is on the tape feeding side. Since they are not aligned, no back tension is applied to the tape.

In this regard, the conventional reel stand rotation stop detection system has a problem of increased back tension during rewinding.

In addition, when the playback operator is operated, that is, the take-up reel stand 1
2 starts rotating, the detection body 29 has already received the biasing force and performs a follow-up operation, so that the engaging portions 27 and 36 will not be accidentally engaged and automatically stopped.

Note that this invention is not limited to the above embodiments.

For example, if first and second idlers having a predetermined diameter are provided as a fast-forwarding idler or a rewinding idler, automatic stopping can be achieved even during fast-forwarding or rewinding.

Further, it is also possible to switch from auto-repeat playback to rewinding by utilizing the detection result that the tape has stopped running, that is, the detection object has moved in the direction of arrow F in FIG. 2C.

In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

Therefore, as detailed above, according to the present invention, it is possible to provide a tape stop detection mechanism that has a small number of parts, has a simple structure, operates accurately, is easily miniaturized, and is particularly suitable for micro cassette tape recorders and the like. can.

[Brief explanation of the drawing]

FIGS. 1a and 1b are a front view and a side sectional view of essential parts, respectively, showing an embodiment of the tape stop detection mechanism according to the present invention, and FIGS. 2a, b, and c are explanatory diagrams of the operation of the same embodiment, respectively. It is. 11...Flywheel, 12...Take-up reel stand, 13...Take-up idler, 14...
...First idler, 15 ... Second idler, 16 ... Rotating shaft, 17 ... Friction member, 18 ... Spring receiver , 19... Spring, 20.21... Rubber ring, 22...
...Movable member, 23...Friction plate, 24...
... Pin, 25 ... Spring, 26 ... Cam member, 27 ... Engagement part, 28 ... Recess, 29 ...・Detection object, 30...Rotation axis, 31...Automatic stop mechanism lever, 32...
...Rotation axis, 33...Lock plate, 34...
...Locking member, 35...Arm part, 36...
- Engagement part, 37... Arm part.

Claims (1)

[Claims] 1. A first rotating body that rotates in conjunction with the reel shaft, a second rotating body that rotates independently of tape running, and that correspond to the first and second rotating bodies, respectively, and are coaxially engaged with each other. The front (4
[, + 'J- Transmit the rotational force of the second rotating body to the first rotating body in the tape winding state of the le axis, and before=p IJ
- third and fourth parts that do not transmit the co-rotating force of the second rotating body to the first rotating body when the tape is fed out;
a biasing force member that is engaged with the third rotating body through a friction mechanism and receives a biasing force due to the rotation of the third rotating body; The detecting body is provided with an engaging part that moves in response to a force and follows the cam part of the fourth rotary body, and is detachably engaged with the cam part of the fourth rotary body when tape running is stopped. A tape stop detection mechanism characterized by: