JPH0544742B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a power mechanism for a tape recorder.
This reduces the impact force applied to the locking means of the power plate and improves the accuracy of the cam stop position.

[Technical Background of the Invention] There are five tape recorder modes: stop, play, fast forward, rewind, and program change.Recently, tape recorders have become more automated, and each mode can be maintained and switched using electromagnetic technology. By utilizing the suction force of the plunger and the driving force of the motor, a tape recorder has been put into practical use that allows switching between modes with the extremely light operation of simply pressing a switch, without requiring any operating force. .

In such an automated tape recorder, various types of power mechanisms have been known for moving each member to a predetermined mode, one of which is a motor as shown in Figure 5. A cam 12 is interlocked with an intermittent gear 11 that intermittently meshes with a drive gear on the side, and the cam 12 reciprocates a power plate 13 to drive driven members such as a head plate and a channel change plate. be. In this type of power mechanism, during a certain mode, the power plate 13 is
4 is used to lock the intermittent part 11a of the intermittent gear 11 at a position facing the drive gear 15, and even if the motor is rotating during execution of that mode, the power plate 13 does not move and the driven member I make sure that it does not move. When changing from that mode to another mode, the locking means 14 is moved by an electromagnetic plunger or other means to unlock the power plate 13, and the intermittent gear 11 is engaged with the drive gear 15 and rotated. A cam 12 of an intermittent gear 11 moves a power plate 13 to the right in the figure, and a driven member interlocking with this power plate 13 is moved to a new mode position.

Further, the power plate 13 is returned to its return direction and is urged by a spring 16, thereby causing the roller 13a on the power plate 13 to move toward the cam 12.
The roller 13a is pressed against the maximum diameter portion 12a.
After overcoming this, the power plate 13 returns to its original position due to the urging force of the spring 16.

Furthermore, the drawing of the cam 12 is performed by the power plate 1.
This is done by the force of the spring 13 of No. 3. That is, the power plate 13 is locked by the locking means 14 as described above, and the intermittent gear 11 is locked.
A locking portion 12b of the cam 12 with the roller 13a when the intermittent portion 11a is brought to a position facing the drive gear 15 is provided in the middle of the inclined surface before the minimum diameter portion 12a. When a drive signal for the power plate 13 is input, the electromagnetic plunger unlocks the locking means 14 of the power plate 13, and when the power plate 13 is moved in the return direction (drawing direction) by the force of the spring 16, the power is Since the roller 13a of the plate 13 is located in the middle of the inclined surface of the cam 12, the cam 12 is pressed, which causes the cam 12 to rotate, and the intermittent gear 11 integrated with the cam 12 to rotate and mesh with the drive gear of the motor. The call is complete.

[Problems with Background Art] However, the power mechanism of the conventional tape recorder as described above has the following drawbacks.

That is, when the motor operates, the force of the spring 16 applied to the power plate 13 becomes a burden, so in order to reduce this burden, the maximum diameter part of the cam 12 that pulls the power plate 13 against the spring 16 is Up to 12a, it is necessary to have a gentle slope, and therefore, the length is required to be long. For this reason, the length after exceeding the maximum diameter portion is relatively shortened, and there is a steeply sloped surface during this period. Therefore, the power plate 13 returns at high speed due to the urging force of the spring 16, and this power plate 13
The biasing force of the spring 16 applied to the power plate 13 is directly applied to the locking means 14 of the power plate 13.
In this case, the spring 16 which has been stretched to the maximum instantaneously contracts, so that a large impact force is applied to the locking means 14. As a result, power plate 1
The durability of the locking means 14 of No. 3 is significantly reduced, which poses a major problem in terms of the performance of the tape recorder.

Furthermore, since the slope from the maximum diameter portion 12a of the cam 12 to the lock portion 12b is in a downward direction with respect to the axis, the rotational force of the cam 12 tends to increase, and therefore, the cam 12 is Due to the rotation, it is difficult to accurately stop the roller 13a at the locking portion 12b, making it impossible to lock the power plate 13, which may cause problems such as the power plate moving again.

[Object of the Invention] The present invention is limited to eliminate the drawbacks of the prior art as described above, and its purpose is to improve the attachment of the spring applied to the power plate by improving the shape of the cam. To provide a power mechanism for a tape recorder which absorbs force, reduces impact force related to a locking means of a power plate, improves its durability, and improves accuracy of lock position.

[Summary of the Invention] The power mechanism of the tape recorder of the present invention has a structure in which a cam provided in an intermittent gear is provided with a step portion having a diameter slightly larger than the lock portion between the maximum diameter portion and the lock portion, thereby achieving power. When the roller of the plate moves from the maximum diameter part to the locking part, most of the biasing force of the spring is absorbed at the stepped part, and when the power plate is locked in the locking means, the locking means Such impact force is reduced.

By configuring this stepped portion to be formed in an arc concentric with the cam or an inclined surface in the opposite direction to the cam, the return spring force received from the roller is received at the axis of the cam, and the rotational force is applied to the cam. Since this is prevented from occurring, there is no need to increase the return speed of the power plate, and there is no inconvenience such as making the cam repeat unnecessary movements and making the power plate unstable.

[Embodiment of the Invention] An embodiment of the power mechanism of the tape recorder according to the present invention as described above will be specifically described with reference to FIGS. 1 and 3.

As shown in FIG. 2, the intermittent gear 1 has an intermittent portion 1a without gear teeth around it.
When it meshes with the drive gear 2 interlocking with the motor, it rotates clockwise in the figure, but when the drive gear 2 faces the intermittent portion 1a, it does not rotate.

A cam 3 is integrally provided on the surface of the intermittent gear 1, and a roller 4a of a power plate 4 is in contact with the outer periphery of the cam 3. And this roller 4
A is always pressed against the outer periphery of the cam 3 by the urging force of a spring 5 which urges the power plate 4 in the return direction (leftward in the figure).

As shown in FIG. 1, the cam 3 rotates clockwise in the figure together with the intermittent gear 1, and the shape from the minimum diameter part to the maximum diameter part 3a is the same as that of the conventional one. Then, between the maximum diameter part 3a and the lock part 3b, a slight slope A is formed, which is adjacent to a steep slope B, and furthermore, in front of the lock part, there is a small slope A. A step C is provided. This stepped portion C is provided in an arc shape concentric with the cam 3 with respect to the axis.

Note that the power plate 4 is configured to be locked by a locking means 6.

The operation of this embodiment having the above configuration is as follows.

That is, as shown in FIG. 2, when the roller 4a of the power plate 4 is located at the maximum diameter portion 3a of the cam 3, the power plate 4 has moved forward to the foremost position.

Next, the roller 4a of the power plate 4 is moved to the cam 3.
When the power plate 4 exceeds the maximum diameter part 3a of
begins to return to the left in the figure by the biasing force of the spring 5 while being guided by the gentle slope A,
As shown in FIG. 2, the roller 4a of the power plate 4
By descending the steep slope B of the cam 3, it rapidly falls toward the small-diameter step C. At this time, in particular, since the shape of the stepped portion C is an arc concentric with the axis of the cam 3, most of the urging force of the return spring 5 received from the roller 4a is absorbed by the axis of the cam 3. It will take the form of Furthermore, since the power plate 4 is temporarily stopped or greatly decelerated at this stepped portion C, no rotational force is generated in the cam 3 as in the conventional case.

Even after most of the urging force of the spring 5 loses its impact, the intermittent gear 1, which is integrated with the cam 3, is rotated slightly by the drive gear 2, so that the roller 4a moves from the stepped portion C. It crosses over and moves to the lock part 3b side, but this stepped part C and the lock part 3b
Since the diameter difference between the power plate 4 and the power plate 4 is minute, the biasing force of the spring 5 applied to the power plate 4 is also minute, and the roller 4a, that is, the power plate 4 moves at an extremely slow speed.

Therefore, as shown in FIG. 3, as the intermittent portion 1a of the intermittent gear 1 faces the drive gear 2, the rotation of the intermittent gear 1 and the cam 3 is stopped, and the power plate 4 is moved to the locking means 6. When locked by
Since power plate 4 is extremely decelerated,
The impact force applied to the locking means 6 is much reduced than before, and the durability of the locking means 6 is improved. In this case, the speed of the cam 3 is also significantly reduced, so there is no risk of the intermittent gear 1 and the drive gear 2 meshing again as in the conventional case, causing the cam 3 to repeat unnecessary operations. There is no inconvenience that would cause the plate 4 to be in an unstable locked state.

Note that the present invention is not limited to the above-mentioned embodiments. For example, the shape of the stepped portion may not be an arc concentric with the axis of the cam, but may be an inclined surface in the opposite direction to the cam, or As shown in FIG. 4, if a brake protrusion 3c is provided on the smallest diameter side of the step, the impact when the roller comes into contact with the step can be released in the opposite direction to the rotation of the cam. more effective.

[Effects of the Invention] As explained above, according to the present invention, by making a simple improvement to the shape of the cam, the impact force applied to the locking means of the power plate is reduced, and its durability is improved. Furthermore, it is possible to provide an excellent tape recorder power mechanism with more stable operation.

[Brief explanation of the drawing]

1 to 3 are plan views showing an embodiment of the power mechanism of a tape recorder according to the present invention, respectively.
Figure 1 is an enlarged view showing the cam, Figure 2 is a view showing the power plate roller in the stepped part of the cam,
FIG. 3 is a diagram showing the state in which the roller of the power plate is in the locking portion of the cam, FIG. 4 is an enlarged diagram showing the cam in another embodiment according to the present invention, and FIG.
The figure is a plan view showing an example of a power mechanism of a conventional tape recorder. 1... Intermittent gear, 1a... Intermittent part, 2... Drive gear, 3... Cam, 3a... Maximum diameter part, 3b...
Lock part, 3c...Protrusion, 4...Power plate, 4a...Roller, 5...Spring, 6...
Locking means, A... gentle slope, B... sharp slope, C... step.

Claims (1)

[Claims] 1. An intermittent gear that is intermittently rotated by a drive gear;
The intermittent gear is equipped with a power plate that reciprocates by the action of a cam, and the movement of this power plate advances each member to the play position or fast forward/rewind position, and after a certain stroke operation, the power plate is engaged. In the power mechanism of a tape recorder configured to be locked by a locking means, a cam provided on the intermittent gear locks the maximum diameter portion for moving the power plate to the frontmost position and the intermittent portion of the intermittent gear to face the drive gear. has a department;
A stepped portion having a diameter slightly larger than the locking portion is provided between the maximum diameter portion and the locking portion, and this stepped portion is formed in an arc shape concentric with the cam or an inclined surface in the opposite direction to the cam. Tape recorder power mechanism.