JPH0690823B2 - Tape recorder auto-stop mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic stop mechanism for a tape recorder in which a stop mechanism operates when the tape stops traveling.

[Prior art]

As an automatic stop mechanism of a conventional tape recorder, as shown in FIG. 12, a heart-shaped bifurcated cam hole 9e is formed in a sensor 9 which is rotationally displaced in relation to the winding direction of a tape (not shown), and the tape running is carried out in the bifurcated cam hole 9e. When the pin 7b of the sensor lever 7 that is always swung is engaged, and the turning force of the sensor 9 disappears, the pin 7b hits the hit portion 9h in the bifurcated cam hole 9e and the sensor lever There is an auto-stop mechanism in which the swing stroke of 7 is limited to perform a stop operation.

Assuming that the sensor 9 is receiving rotational force in the direction of the solid line arrow in this auto stop mechanism, the sensor lever 7 is being swung by the cam surface 6a, and now the hit pin 7b is in the direction of the arrow in the explanation of FIG. Moving to. The bifurcated cam hole 9e is about to move in the direction of the solid arrow. If this continues, the pin 7b will enter the inner end 9g of the bifurcated cam hole 9e, but if the operation of reversing the tape running direction is performed with this, the sensor 9 receives the opposite turning power, Bifurcated cam hole
Since 9e moves in the direction of the dotted line in FIG. 10, the hit pin 7b may collide with the hit portion 9h of the bifurcated cam hole 9e. If there is a collision during the direction change, the hit pin 7b remains on the hit portion 9h of the bifurcated cam hole 9e, which causes a disadvantage that the auto stop operation is performed.

Further, if the tape has a slack, there is a disadvantage that the sensor 9 does not have a rotational force and a malfunction occurs.

[Object of the Invention]

In view of the above-mentioned drawbacks, the present invention provides a confirmation mechanism for confirming the disappearance of the rotational force of the sensor by slightly swinging the sensor lever shortly after the contact pin and the contact portion are contacted with each other. It is to propose an auto-stop mechanism for a tape recorder that prevents malfunctions due to slack in the tape during conversion.

[Structure of Invention]

The present invention has a sensor having a bifurcated cam hole that is rotationally displaced in relation to the winding direction of the tape, and a hit pin that fits into the bifurcated cam hole that is constantly swung regardless of the tape running. A stop-mechanism including a sensor lever, wherein when the turning force of the sensor is lost, the hit pin hits a hit part in the forked cam hole to limit a swing stroke of the sensor lever to perform a stop operation. In the above, there is provided a confirmation mechanism for confirming the disappearance of the turning force of the sensor by slightly swinging the sensor lever shortly after the hit pin and the hit portion are hit.

〔Example〕

The present invention will be described below with reference to the illustrated embodiment. FIG. 1 is an exploded perspective view showing the auto stop mechanism 100 and related mechanisms,
FIG. 2 is a perspective view of the auto stop mechanism 100 removed from the substrate 1, and FIG. 3 is a perspective view of the auto stop mechanism. In the tape recorder, the head substrate 10 is placed on the substrate 1 in FIGS. 1 to 3, and the push button 11 for fixing the push button for selectively performing various operations of the tape recorder is fixed to the push button 11. , The head substrate 10 is moved back and forth by the recording / re-operation lever 2 or the like. On the lower side of the board 1, an auto shut-off board 3 incorporating various elements of the auto stop mechanism 100 is attached.

Further, below the substrate 1, a motor 12 is attached to a substrate (not shown). The motor 12 is rotated at a constant speed and the belt 13
The flywheel 14 is rotated in the direction of the arrow via. A capstan shaft 15 is fixed to the flywheel 14, and the capstan shaft 15 is projected to the upper surface of the substrate 1. The idler 4 projecting from the substrate 1 is rotated in the direction of the arrow from a flywheel 14 or a motor 12 by suitable transmission means. The reel spindles 16 and 17 rotatably provided on the substrate 1 are fitted into the tape winding hubs on the winding side and the supply side, respectively, when a cassette (not shown) is mounted. A gear 18 is attached to the reel spindle 16 via a means such as friction transmission, and a take-up idler 19 for taking up the tape during constant-speed tape feeding is faced so as to be meshable. The take-up idler 19 is supported by the lever 5. The lever 5 is rotatably supported on the substrate 1 by a shaft 36. The take-up idler 19 transmits low speed rotation from the small diameter gear 4a of the idler 4 to the reel spindle 16. The means for transmitting the friction is such that there may be a speed difference generated between the constant tape feeding and the constant rotation winding of the reel spindle 16.

Although not shown, means such as friction transmission is provided so that the motor, flywheel and other necessary parts can continue to rotate even if the reel spindle rotation is stopped even when the tape reaches the end.

A pinch arm 20 is supported on the head substrate 10, and a pinch roller 21 is supported on the pinch arm. The pinch roller 21 advances the tape during recording / playback to cap the tape on the capstan shaft.
Insert it between 15 and feed at a constant speed. Further head substrate 10
An erasing head 22 and a recording / playback head 23 are fixed on the top.

Explaining the auto stop mechanism, a cam gear 6, a sensor lever 7 and a control lever 8 are rotatably or rotatably attached to the attachment shafts 3a, 3b, 3c of the auto shutoff substrate 3. The center hole of the cam gear 6 is rotatably fitted to the mounting shaft 3a of the auto shutoff substrate 3. The cam gear 6 has three cam surfaces.
The cam surface 6a surrounds the center and is eccentrically placed, and has a substantially elliptical shape. The cam surface 6b guides the first driven piece 7a of the sensor lever 7 from the middle in the radial direction outward. The cam surface 6c is near the outer periphery and guides the second driven piece 7c of the confirmation mechanism slightly inward.

The sensor lever 7 has a rotation shaft hole at approximately the center thereof and is rotatably fitted to the mounting shaft 3b of the auto shutoff substrate 3. The sensor lever 7 has a shape including a branch extending in both directions and a branch described laterally.

There is a first driven piece 7a projecting downward at the tip of the laterally extending branch and is associated with the cam surfaces 6a and 6b of the cam gear 6.

The tip of the branch that extends forward has a pin 7b that projects upwards.
There is a double-ended cam hole 9e in the heart shape of the sensor 9.
Is involved.

Also, the second driven piece 7c of the confirmation mechanism that projects downward near the tip
And is related to the cam surface 6c of the cam gear 6.

The branch extending rearward is bifurcated, and one tip 7d thereof faces the locking plate 24, and another tip 7e of the branch having elasticity has faced the switch plate 25. The locking plate 24 and the switch plate 25 are arranged so as to overlap each other, and are biased to the right side in FIG. 1 by springs 26 and 27, respectively.

The control lever 8 has a rotation shaft hole at substantially the center thereof, has a branch extending in both directions, and is rotatably attached to the attachment shaft 3c of the auto shutoff substrate 3.

The control lever 8 has a tip 8a related to other members and engaging portions 8b, 8c and 8d. These will be described in the operation description.

A spring 28 is hooked between the sensor lever 7 and the control lever 8 to generate counterclockwise turning force on both levers.

Therefore, the driven piece 7a of the sensor lever 7 is normally in contact with the cam surface 6a of the cam gear 6.

The sensor 9 is a lever having a substantially Y shape, and has a shaft 9a projecting upward in the central portion thereof.
It is rotatably fitted in a shaft hole 29a opened from below 29.

From one tip of the Y-shaped branch, there is a spring-shaped branch 9b that makes a U-turn toward the center of the branch. And when the assembled auto stop mechanism 100 is attached to the substrate 1,
The protrusion 3d provided on the auto shutoff substrate 3 is arranged to push up the tip of the spring-like branch 9b. axis
Three protrusions 9c stand on both sides of 9a. The protrusion 9c is the substrate 1
It reaches the lower surface 30a of the gear 30 that moves integrally with the reel spindle 16 through a fan-shaped hole 1a opened in the.

And, the springy nature of the springy branch 9b always causes light pressure contact.

Therefore, the sensor 9 can be rotationally displaced in the rotational direction of the reel spindle 16 within a certain range.

One protrusion 9d stands on the lower side of one of the protrusions 9c.

The tip 8a of the control lever 8 hits the protrusion 9d to give a counterclockwise turning force to the sensor 9. The magnitude of the turning force is set to be larger than the turning force generated by the pressure contact with the reel spindle 16.

Another Y-shaped branch has a heart-shaped bifurcated cam hole 9e having an extension.

Pin 7b is attached to the tip of the sensor lever 7 in the bifurcated cam hole 9e.
Is included.

A protruding piece is provided below the end of the lever 5 on which the winding idler 19 is placed.
There is 5a. When the take-up idler 19 reaches the take-up position, the protrusion 5a pushes the engaging portion 8b of the control lever 8 to give the control lever a rotational displacement in the clockwise direction.

The shaft 31 of the idler 4 is supported by a lever 32, and the lever 32
Is supported by the shaft 33 through the long hole 32a so that the position of the tape can be moved for fast-forwarding and rewinding the tape. When the position is moved and the idler 4 performs fast forward or rewind transmission, the engaging portion 32b or 32c of the lever 32 pushes the engaging portion 8c or 8d of the control lever 8 to move to the control lever 8. It gives a rotational displacement in the clockwise direction.

In any case, when the idler 4 is in the transmission state, the control lever 8 is rotationally displaced in the clockwise direction, and the sensor 9 is released from the control lever 8.

The locking plate 24 holds the operation lever 2 to which the push button 11 is fixed in the operated state. The switch plate 25 is designed so that the switch 34 is turned on when the push button 11 is pushed into the operating state.

Ends 24a and 25a of the locking plate 24 and the switch plate 25 face the bifurcated tips 7d and 7e of the sensor lever 7.

When the sensor lever 7 rotates in the clockwise direction, they are pushed and the locking plate 24 unlocks the push button 11, and the switch plate 25
Keeps the switch 34 in the ON state.

The operation of the automatic stop mechanism of the tape recorder will be described. FIGS. 4 to 9 show the positions of the respective mechanical members in relation to the rotation of the cam gear 6, and for example, in order to perform a reproducing operation. Push button 11 to spring 35 in FIG.
Suppose you push it against.

The push button 11 and the operating lever 2 move members necessary for the operation, and the projection 2a of the operating lever 2 is locked by the locking portion 24b of the locking plate 24.

At the same time, the switch plate 25 is displaced by the protrusion 2a 'of the operating lever 2 and the switch 34 is turned on. The protrusions 2a and 2a 'are the same protrusion. The locking plate 24 and the switch plate 25 are shown side by side for the sake of clarity.

When the operation starts in this way, the cam gear 6 is rotated in the direction of the arrow.

The reel spindle 16 also rotates, and the sensor 9 pressed against the reel spindle 16 via the projection 9c also receives rotational force.

The rotation direction of the sensor 9 is, for example, the direction of the solid arrow in FIG. 4 in the case of reproduction and fast-forwarding, and the direction of the opposite dotted line in the case of rewinding.

Before the rotation of the reel spindle 16, the sensor 9 receives the turning force in the arrow direction at the tip 8a of the control lever 8, but when the rotation to the reel spindle 16 is transmitted, the control lever 8 turns clockwise. Since the sensor 9 is dynamically displaced, the sensor 9 is no longer affected.

The operation will now be described starting from the state shown in FIG. Although the sensor lever 7 receives a counterclockwise turning force by the spring 28, the drawing shows the case where the first driven piece 7a comes into contact with the farthest place of the cam surface 6a of the cam gear 6.
The hit pin 7b at the tip of the sensor lever 7 is located at the base 9f of the extension of the bifurcated cam hole 9e of the sensor 9.

When the cam gear 6 rotates in the direction of the arrow, the sensor lever 7 rotates counterclockwise along with the retreat of the cam surface 6a, and the state shown in FIG. 5 is obtained.

If the reel spindle 16 is rotating during this period, that is, if the tape is being fed, the sensor 9 is given a turning force, so the wall of the bifurcated cam hole 9e is located inside the tip of the sensor lever 7. It will always follow pin 7b.

Therefore, as shown in FIG. 5, when the sensor lever 7 is pivotally displaced in the most counterclockwise direction, the advance of the pin 7b at the tip end of the sensor lever 7 is performed without being obstructed in the bifurcated cam hole 9e of the sensor 9, It reaches one of the sending ends 9g of the bifurcated cam hole 9e.

The innermost end depends on the rotation direction of the reel spindle 16, that is, whether the tape is wound, fast wound, or rewound. In the case of FIG. 5, it is in the state of winding or fast winding.

Subsequently, the sensor lever 7 is the cam surface 6a of the cam gear 6.
A clockwise rotational displacement is performed by.

The first driven piece 7a of the sensor lever 7 passes between the two cam surfaces 6a and 6b of the cam gear 6.

The hit pin 7b at the tip of the sensor lever 7 advances along the bifurcated cam hole 9e of the sensor 9 and reaches the base 9f of the extension.

During this time, the sensor 9 is pulled back to the initial position against the rotational force received from the reel spindle 16.

Thus, the state shown in FIG. 4 is obtained, and the states shown in FIGS. 4 and 5 are repeated while the tape is running.

It is now assumed that the tape has reached the end and the reel spindle 16 has stopped.

After the state shown in FIG. 4, the sensor lever starts rotating counterclockwise.

But this time, since the reel spindle 16 is stopped,
The sensor 9 is also in that position even if it does not receive the turning force.

Then, the hit pin 7b at the tip of the sensor lever 7 advances in the middle of the bifurcated cam hole 9e and hits the hit portion 9h projecting to the center of the heart shape.

That is, the counterclockwise rotation of the sensor lever 7 is disturbed on the way. This state is shown in FIG.

The motor 12 is still rotating and the cam gear 6 is also rotating, as shown in FIG.

The first driven piece 7a of the sensor lever 7 is separated from the cam surface 6a. Then, the cam surface 6b approaches soon.

This time, the cam surface 6b causes the sensor lever 7 to pivot largely clockwise. This state is shown in FIG.

When the sensor lever 7 pivots largely clockwise, the tip 7d of the bifurcated branch pushes the end 24a of the locking plate 24 to unlock the operating lever 2, and the tip 7e of the bifurcated branch 7e of the switch plate 25. Prevents coming back and keeps switch ON.

When the cam gear 6 continues to rotate, the sensor lever 7 moves to the first position.
The driven piece 7a excessively takes the end piece of the cam surface 6b and falls into the cam surface 6a.

Since the sensor lever 7 rotates counterclockwise, the tips 7d and 7e of the two forks also stop pressing the locking plate 24 and the switch plate 25 and allow them to move freely.

The push button 11 is released, and the idler 4 and the take-up idler 19 also return to the position where the rotation transmission is stopped, so that the control lever 8 rotates counterclockwise to give the sensor 9 counterclockwise rotation force.

The control lever 8 allows the sensor 9 to work only when the reel spindle 16 is in a state to be rotated, and prevents the automatic stop when unnecessary.

This completely returns to the state before the push button operation, and the next operation is possible. FIG. 9 shows the state at this time.

Although the auto-stop mechanism works in this way, there is a small chance of accidentally performing the auto-stop in actual use.

FIG. 10 is a diagram for explaining the occurrence of malfunction, in which the pin 7b at the tip of the sensor lever 7 and the bifurcated cam hole 9e of the sensor 9 are enlarged.

Now, FIG. 10 is about to change from the state of FIG. 4 to the state of FIG.

In FIG. 10, the pin 7b is moved in the direction of the arrow.

The bifurcated cam hole 9e is about to move in the direction of the solid arrow.

If this continues, the state shown in FIG. 5 is reached, but it is assumed that an operation for reversing the tape running direction is performed. In this example, winding or early winding is changed to rewinding.

Then, since the rotation of the reel spindle 16 is reversed, the bifurcated cam hole 9e moves in the direction of the dotted arrow and its wall hits the pin 7b.
Until it hits.

Then, the hitting pin 7b enters one of the innermost ends 9g 'opposite to the previous one, and then the state shown in FIG. 4 is reached, so that a new operation is continued.

However, since the hit pin 7b moves in the direction of the arrow, if it is unlucky, the hit pin 9b may collide with the hit portion 9h during the movement of the bifurcated cam hole 9e.

If the rotation power transmission from the reel spindle 16 to the sensor 9 is sufficiently large, the rotation is performed even if there is a collision, and the pin 7b can be inserted into the inner end 9g '.

However, the reel spindle 16 does not want to be given an extra load, and the transmission force to the sensor 9 is kept small.

Therefore, if there is a collision during the change of direction, the hit pin 7b often remains on the hit portion 7h of the bifurcated cam hole 9e.

In this case, the state shown in FIG. 6 is established, and as described above, the auto-stop operation shown in FIG. 7 and thereafter is performed.

In other words, you will accidentally stop automatically.

In the present invention, this malfunction is prevented by the following confirmation mechanism.

The confirmation mechanism is the cam surface 6c of the cam gear 6, and after the second driven piece 7c of the sensor lever 7 hits the hit pin 7b and the hit portion 9h, slightly swings to rotate the sensor 9. It is configured to confirm the loss of power.

The operation of the confirmation mechanism is shown in FIG. 6 on the cam surface of the cam gear 6.
6c approaches the second driven piece 7c protruding downward from one branch of the sensor lever 7.

This will come into contact soon, but at this time the sensor lever 7 is made to rotate slightly clockwise.

As a result, the hit pin 7b, which was placed on the hit portion 9h of the heart-shaped bifurcated cam hole 9e, is slightly separated.

At this time, reel spindle 16 for tape feeding in the opposite direction
If is rotated, the sensor 9 is rotated, and then the hit pin 7b enters the inner end 9g 'of the bifurcated cam hole 9e.

Therefore, there is no automatic stop.

If the reel spindle 16 is really stopped at the end of the tape, the sensor lever 7 is slightly rotated clockwise by the cam surface 6c of the cam gear 6, and the hit pin 7b is the hit portion 9h of the bifurcated cam hole 9e. Since the sensor 9 does not move even if it is separated from the position, when the cam surface 6c passes by, the pin 7b for hitting is put on the part 9h for hitting again, and the state shown in FIG. 7 is reached. Done.

The cam surface 6c of the cam gear 6 can come into contact with the second driven piece 7c of the sensor lever 7 when the hit pin 7b of the sensor lever 7 is placed on the hit portion 9h of the forked cam hole 9e. When the hit pin 7b of the sensor lever 7 is already in the inner end 9g of the bifurcated cam hole 9e, the cam surface 6c passes by the second driven piece 7c and does not interfere with each other.

The path of this cam surface 6c is shown by a dotted arrow in FIG.

FIG. 11 shows the rotation or the passage of time of the cam gear 6 on the horizontal axis and the clockwise rotational displacement of the sensor lever 7 on the vertical axis.

The rotational displacement amount is shown by a dotted line. If the reel spindle 16 is rotating, as described above, the first driven piece 7a of the sensor lever 7 is in constant contact with the cam surface 6a, and accordingly, the rotational fluctuation amount follows the dotted lines A, B, C.・ Passes like D.

If the sensor 9 is stopped, hit the pin at B.
A collision occurs between 7d and the contact portion 9h between the forked cam hole 9e.

Since the sensor lever 7 is not rotated thereafter, the dotted line E
It passes like.

Next, since the cam surface 6c contacts the second driven piece 7c, the sensor lever 7 rotates slightly clockwise.

This progresses as shown by the dotted line F.

When the cam surface 6c has passed and the sensor 9 has stopped, a collision again occurs at the hitting portion 9h, the rotation of the sensor lever 9 remains at the position G, and the cam surface 6b that follows continues to generate H. It turns greatly.

If the sensor 9 rotates while passing the position of F, the collision at the hitting portion 9h no longer occurs, and the hitting pin 7b enters the inner end 9g 'of the bifurcated cam hole 9e. Therefore, the sensor lever 7 The rotation of is at the same position as the passage from C, and then proceeds like D.

One of the causes of the malfunction is that the tape running direction has changed just before B, but this will be reconfirmed and corrected at F later.

Another operation of the present invention, which is to prevent malfunction due to tape slack, is as follows.

It is assumed that the reel spindle without the sensor 9, that is, the reel spindle 17 on the rewinding side in this case, is used to wind the tape.

If the tape has slack, it will happen that the reel spindle 16 with the sensor 9 does not rotate until the amount of slack has been wound up.

In other words, even if the tape stops, the auto stop mechanism may malfunction.

The chance of this occurrence is in the transition from the state of FIG. 4 to the state of FIG. As shown in FIG. 11, it is the period from A to B.

During this time, if the reel spindle 16 is still stopped due to the slack of the tape, the hit pin 7b is placed on the hit portion 9h of the bifurcated cam hole 9e and automatically stops.

However, since the cam surface 6c and the second driven piece 7c are reconfirmed later at F, the reel spindle 16 may be rotated by this time.

This time, the reel spindle 16 may remain stopped during the period from A to F.

The amount of tape slack will be up to about 3.5 times that of AB, and malfunctions due to this will be greatly improved.

When the automatic stop mechanism of the tape recorder is configured as described above, the sensor lever 7 is slightly swung by the confirmation mechanism having a simple structure including the cam surface 6c and the second driven piece 7c, and the contact portion of the bifurcated cam hole 9e is contacted. By temporarily releasing the pin 7b on the 9h, it is confirmed that the rotational force of the sensor 9 has disappeared and the malfunction is prevented.

〔The invention's effect〕

Since the present invention is configured as described above, the turning mechanism of the sensor is rotated by slightly swinging the sensor lever with a simple checking mechanism and temporarily releasing the hit pin mounted on the hit part of the bifurcated cam hole. It is possible to provide an auto-stop mechanism for a tape recorder, which has excellent effects such as the disappearance of a tape is confirmed and a malfunction is prevented.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is an exploded perspective view of an auto stop mechanism of a tape recorder, FIG. 2 is an exploded perspective view of the tape recorder with the auto stop mechanism removed, and FIG. 3 is a diagram of the auto stop mechanism. FIG. 4 is a perspective view, FIG. 4 to FIG. 9 are explanatory views of the operation of the automatic stop mechanism, FIG. 10 is an explanatory view of the operation of the sensor, and FIG. FIG. 12 is a plan view of a main part of a conventional auto-stop mechanism, in which the rotational displacement amount is represented on the vertical axis. 6c, 7c …… Confirmation mechanism, 7 …… Sensor lever, 7b …… Pin per degree, 9 …… Sensor, 9e …… Forked cam hole, 100…
… Auto stop mechanism.

Claims (1)

[Claims] 1. A sensor having a bifurcated cam hole which is rotationally displaced in relation to a tape winding direction, and a hit pin which fits in the bifurcated cam hole which is constantly swung regardless of tape running. A stop mechanism that performs a stop operation by restricting the swing stroke of the sensor lever by hitting the hitting pin in the bifurcated cam hole when the turning force of the sensor disappears. In the case where the hitting pin and the hitting portion come into contact with each other, the sensor lever is slightly swung, and when the hitting pin and the hitting portion come into contact again, the rotation force of the sensor disappears. An automatic stop mechanism for tape recorders, which is equipped with a confirmation mechanism to confirm.