JPS6235153Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an auto-reverse mechanism suitable for magnetic recording and reproducing devices, particularly for in-vehicle tape players such as car stereos.

Some auto-reverse mechanisms in vehicle-mounted tape players and the like employ a system in which the driving force of the reel base is switched by a power gear having an intermittent gear driven by a motor in response to a reverse operation. In such an auto-reverse mechanism, the power gear has an intermittent gear in order to temporarily cut off the power when the reverse operation is completed as described above, but in order to restart the power after the power is cut off, the power gear has an intermittent gear to mesh with other gears. It is necessary to give attracting power to

Therefore, in the past, as shown in FIG. 6a, for example, a power transmission plate PT pivoted by a power gear PG was used.
The springs S ₁ and S ₂ are engaged with the intermittent gear part G.
It was designed to give it the ability to attract people. However, in the same figure, H is an elongated hole provided in the power transmission plate PT.
The eccentric pin P of the power gear GT is loosely fitted into this hole. Alternatively, as shown in FIG. 6b, one end of the pivoted link R is engaged with the power transmission plate PT and the other end is engaged with the spring S to apply the above-mentioned attracting force.

However, either type requires a member to provide a drawing force, which poses problems in terms of space, number of parts, etc.

The present invention has been made to improve the problems of the prior art, and includes forming two pinch roller switching holes with slopes in the change plate, and in response to the movement of the change plate, the pinch rollers can be switched between the pinch rollers by the slopes. The present invention is characterized in that the pressure between the pinch roller and the capstan shaft is released, and the reaction force remaining at that time is used to attract the intermittent gear portion of the power gear.

The present invention will be described below with reference to embodiments shown in the drawings. First, a magnetic tape end (reel base rotation stoppage) detection mechanism for automatically starting the auto-reverse mechanism of the present invention will be explained.

FIG. 1 shows an example of the above detection mechanism, 1 is a motor, 2 and 3 are flywheels, 4 is a tension pulley, 5 is a belt, 6 is a reduction gear mechanism, 7 is a crank arm, 8 is a first lever, 9 is a second lever, 10 is an engagement pin, 11 and 12 are reel bases, 13 is a swinging member, and 14 is a spring.

The swinging member 13 is the reel base 11 (or 12)
is pivotably supported around a rotating shaft 15 as a fulcrum,
A Y-shaped groove 16 is formed in the member. An engagement pin 10 erected at one end of the first lever 8 is freely engaged with the groove 16, and the other end of the lever is connected to the crank arm 7. Furthermore, the first lever 8 is connected to the second lever 9 by a shaft 17, and as will be described later, the degree of connection is such that it can normally rotate around the shaft 17, and when the reel stand stops rotating, both levers are integrated. It is set to such an extent that it can be rotated.

Further, a spring 14 is engaged with the second lever 9 so that it can rotate about a shaft 18 as a fulcrum.

The rotation of the motor 1 is transmitted by the belt 5 to the flywheels 2 and 3 for driving the reel base and the tension pulley 4, and the rotation of the tension pulley causes the crank arm 7 to be transmitted via the reduction gear mechanism 6.
is forced to reciprocate.

Due to this reciprocating movement of the crank arm 7, the first lever 8 rotates about the shaft 17 as a fulcrum as shown in the figure while the reel base 11 is rotating, and the engagement pin 10 is inserted into the groove 16 of the swinging member 13, e.g. If the reel base 11 is on the winding side of the magnetic tape, the first
The swinging member 13 moves freely along the groove portion ₁₆₁ , and swings around the rotating shaft 15 of the reel base 11 as a fulcrum.

When the magnetic tape is completely wound, reel base 1
1 stops rotating, the engagement pin 10 moves from the first groove portion 16 ₁ to the third groove portion 16 ₂ and once contacts the tip of the groove portion, the swinging member 13
is positioned so as to be substantially orthogonal to the first lever 8, and then comes into contact with the protruding portion ₁₆₄ at a position corresponding to the third groove portion ₁₆₂ . As a result, the first lever 8
rotates this engagement pin 10, and together with this, the second lever 9 rotates about the shaft 18 against the bias force of the spring 14, so that the rotation of the reel base 11 is stopped and the rotation of the reel base 11 is stopped. The end of the tape can be detected. Specifically, for example, the second lever 9
The auto-reverse mechanism is activated in response to the rotation of the

FIG. 2 shows yet another tape end detection mechanism, in which the same reference numerals as in FIG. 1 represent members with the same or similar functions, and the member that is particularly different from that in FIG. 1 is a swinging member 13'. The portion corresponding to the second groove portion has a deformed shape as shown in the figure. That is, the first groove portion 16' ₁ the third groove portion 1
6 _{' 3} and the protruding portion 16' ₄ have almost the same shape as in FIG _. 1
6' ₇ and a seventh groove portion 16' ₈ .

Now, in the example of FIG. 2, when the reel berth 11 is on the tape winding side, the rotation stop detection operation is the same as that in FIG. 1, but when it is on the tape supply side, it is as follows.

In this case, first, the engagement pin 10 is inserted into the fourth groove portion 1.
6' ₅ to the fifth groove portion 16' ₆ and abuts the tip of the fifth groove portion 16' 6, the swinging member 13' is temporarily moved to the first lever 8.
After being positioned substantially perpendicular to the groove 16', the groove _16'7 is moved along the sixth groove portion 16'7. The sixth groove portion _16'7 is formed in an arcuate shape as shown in the figure, and the engagement pin 10 slides along this to rotate the swinging member 13' in the direction of the arrow. Then, it reaches the third groove portion _16'3 via the seventh groove portion _16'8 , and abuts the tip thereof, and once the swinging member 13' is positioned almost perpendicular to the first lever 8, it is engaged. The pin 10 has a protrusion 16'
When the first lever 8 makes contact with the first lever ₄ and rotates about the second lever 8, the second lever 9 is rotated against the bias force of the spring 14.

Fig. 3 shows an auto-reverse power transmission mechanism using the principle of the detection mechanism described above, in which 20 is a check plate, 21 is a locking link, 22 is a cam, 23 is a power gear, and 24 is a swinging gear. . The check plate 20 is pivotally supported by the shaft 25, and the pin 10 at the tip is loosely fitted into the end detection groove (not shown since it is the same as in FIG. 2) of the swinging member 13' as described above. A bias force in the counterclockwise direction is applied by a spring 26.

The lock link 21 is pivotally supported by a shaft 27 through a first groove 28 of the check plate 20, and a pin 29 provided on the lower surface of the lock link 21 is attached to the check plate 20.
It is loosely fitted into the second groove 30, and a counterclockwise bias force is applied by a spring 31.

The cam 22 has locking portions 32 and 33,
Normally, the claw portion 34 of the locking link 21 is locked to one of the locking portions 32.

The power gear 23 has an intermittent gear 35 and a shaft 36
A pin 37 is provided at a position eccentric from the
Further, the swinging gear 24 swings the check plate 20. These gears 23, 24
The cam 22 and the cam 22 are provided coaxially and are driven by a motor or the like (not shown).

Now, as mentioned above, when the end of the magnetic tape is detected, that is, when the rotation of the reel base 11 stops,
The check plate 20 rotates slightly clockwise against the bias force of the spring 26. As a result, the pin 29 of the locking link 21 comes into contact with one end surface of the second groove 30 of the check plate 20, and the spring 3
1, the claw portion 34 is released from the locking portion 32 of the cam 22.

Therefore, when the power gear 23 rotates and makes about half a turn, the check plate 20 and therefore the locking link 21 have returned to their original positions. be done.

In this way, the power gear 23 is reliably locked every half rotation at the end of the tape, and by operating the reel-based driving force switching means using the pin 37, an auto-reverse operation can be performed.

FIG. 4 shows an idler switching mechanism as an example of the driving force switching means. In the same figure, 41 is a change plate, 42 is a coupling link, 4
3 is a power transmission plate, 44 and 45 are idlers, 4
6 and 47 are reel bases, 48 and 49 are connection gears, 51 is a board, 52 and 53 are connection plates, 54
and 55 are pivot shafts, and 56 and 57 are switching parts.

The change plate 41, the coupling link 42, and the power transmission plate 43 are connected to the base plate 5 as shown in the figure.
1, and the change plate 4
1 is supported on a base plate 51 so as to be pivotable in the direction of the arrow, and one end of the coupling link 42 is connected to the change plate 41, and the coupling link 42 is pivotally supported on the base plate 51 by a shaft 58.

The power transmission plate 43 has one end with a coupling.
It is connected to the other end of the link 42, is supported on the base plate 51 so as to be pivotable in the direction of the arrow, and is connected to the elongated hole 3.
9 is formed, and the pin 37 of the power gear 23 having the intermittent gear 35 is loosely fitted into the elongated hole.

The idlers 44 and 45 are engaged with connecting gears 48 and 49, and their shafts are connected by connecting plates 52 and 53, respectively, and are normally engaged with the reel bases 46 and 47 by springs 41. is energized by

The shafts 62, 63 of the connecting gears 48, 49 are fixed to the base plate 51, whereas the shafts 64, 65 of the idlers 44, 45 are only placed on the base plate 51, so the idlers 44, 49, 45 is spring 61
It is possible to rotate around the connecting gears 48, 49 within a certain range against the bias force of.

Further, a connection gear 48 is engaged with the power gear 23, and a connection gear 49 is engaged with the gear 48, respectively. Therefore, the reel bases 46 and 47 rotate in different directions.

Further, as shown in the figure, the power transmission plate 43 is provided with switching parts 56 and 57 in the upper part, and these switching parts switch the idler 4 according to the pivoting of the power transmission plate 43.
4 and 45, respectively.

Further, since other tape recorder members are not directly related to the gist of the present invention, they have been omitted for ease of explanation.

Now, when the power gear 23 is unlocked,
Since the power gear rotates counterclockwise and the pin 37 also rotates in the same direction, the power transmission plate 43 having an elongated hole 39 that loosely fits with the pin 37 pivots in the direction of the arrow.

Therefore, for example, when the switching portion 57 of the power transmission plate 43 engages with the shaft 65 of the idler 45 as shown in FIG.
The engagement with the reel base 46 is released, and the idler 44 and the reel base 46 are engaged with each other.

On the other hand, as shown in FIG. 5b, when the switching portion 56 of the power transmission plate 43 engages with the shaft 64 of the idler 44 in the next half rotation of the power gear 23,
The engagement between the idler 44 and the reel base 46 is released, and the idler 45 and the reel base 47 are engaged.

Thus, by applying a switching force to the power transmission plate 43 by the power gear 23, the idler and the reel base can be switched and an auto-reverse operation can be performed.

Now, in the present invention, the change plate 41 is constructed as shown in FIG. 4b. In the same figure,
H ₁ and H′ ₁ are the pinch roller switching holes, and the slopes are respectively
It has HL and HL′. P ₁ , P′ ₁ are pinch rollers,
It is rotatably placed on pinch roller stands P ₂ and P′ ₂ . The pinch roller stands P ₂ , P′ ₂ are supported by shafts P ₅ , P′ ₅ , and springs P ₃ , P′ ₃ are wound around the shafts, and the tips thereof are connected to the pinch roller switching rollers.
P ₄ , P′ ₄ , and the rollers are engaged with long holes H ₂ , H′ _{2 .}
It is possible to move inside.

Therefore, the change plate 41 is now shown in FIG.
When the roller _P4 moves to the left as shown in the figure, the spring _P3
The pinch roller stand _P2 rotates about the axis _P5 as a fulcrum, and the pinch roller _P1 separates from the capstan axis c'.

On the other hand, since roller P′ ₄ leaves slope HL′,
The pinch roller _P'1 is pressed against the capstan shaft c' by the bias force of the spring _P'3 , thereby causing the tape to run.

However, at this time, the reaction force F that releases the pinch roller P ₁ from the capstan shaft c is acting on the slope HL of the change plate 41 as described above, and therefore the change plate 41 is moved in the opposite direction, that is, to the right. Power will come into play. This force is transmitted to the power transmission plate 43 via the coupling link 42, and is applied as a call-in force to the intermittent gear portion of the power gear.

Even when the change plate 41 moves to the right side, as is clear from FIG. 4c, a retraction force can be generated. Note that the means for transmitting power to the change plate is not limited to the above-mentioned configuration, but may be any means as long as it can operate the driving force switching means of the reel base in response to the operation of the reel base.

FIG. 7 shows an example in which the mechanisms shown in FIGS. 3 and 4 are incorporated into an on-vehicle tape player. In the figure, M is a motor, D ₁ and D ₂ are power transmission belts, F ₁ and F ₂ are flywheels, P ₁ and P ₂ are pinch rollers, and C ₁ and C ₂
is the capstan shaft.

As is clear from the above explanation, according to the present invention, the pull-in force of the power gear is generated by the claw portion having a spring effect formed integrally with the change plate. It is advantageous in this respect.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams showing the magnetic tape end detection device, Figures 3 a, b and c are schematic diagrams showing the auto-reverse power transmission mechanism, and Figures 4 a and b.
and c are schematic diagrams showing an embodiment of the present invention, Figs. 5 a and b are explanatory diagrams of its operation, Figs. The figure is a schematic diagram showing one embodiment of the present invention. 1...Change plate, 2...Coupling link, 3...Power transmission plate, 23...Power gear, 76...Claw portion, SW...Slide switch.

Claims (1)

[Scope of utility model registration request] An auto-reverse mechanism for a magnetic recording and reproducing device includes: a driving force switching means for a reel base; a means for detecting rotation stoppage of the reel base; a means for rotating a power gear having an intermittent gear in response to the detection means; It has means for operating the driving force switching means and the change plate by rotation of the power gear, and a spring that rotatably supports two pinch rollers and always applies a bias force to the pinch rollers in a direction in which they are pressed against the capstan shaft. and a rotatable support means, the change plate is provided with two holes having slopes, and movement of the change plate causes the support means to rotate on the slope against the bias force of the spring. the pinch roller is separated from the capstan shaft, and the reaction force applied to the slope at this time draws the power gear to engage the intermittent gear with another gear. mechanism.