JPS61104453A - Power mechanism of tape recorder - Google Patents

Abstract

PURPOSE:To reduce the load applied to a lock member for members to be driven and to improve the durability of the lock member, by forming a gentle slope over the surface of a cam set to an intermittent gear which covers the maximum diameter part through a diameter part where the member to be driven is held by the lock member. CONSTITUTION:When a roller 4a of a power plate 4 gets over the maximum diameter part 3a of a cam 3, the plate 4 starts its resetting action to the left side by the energizing power of a spring 5 with the guidance given from a sloping surface A. Then the roller 4a moves down a little along the surface A of the cam 3 to a lock diameter part 3a. When the plate 4 is reset by an amount equal to an overstroke, a lock part 8a of a lock member 8 interlocks a projected part 6a of a head lock plate 6. Thus the plate 6 is locked. In this case, both plates 4 and 6 are decelerated since the roller 4a is guided by the surface A. Thus the energizing power of a return spring 5 is almost applied to the cam 3. In addition, the energizing power of a spring 7 is not applied instantaneously.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a power mechanism for a tape recorder, and in particular improves the shape of a cam to reduce the load on a locking member that locks a driven member. It pertains to what has been done.

[Technical Background of the Invention] There are five modes for tape recorders: stop, play, fast forward, rewind, and program change.
Recently, tape recorders have become more automated, and each mode can be maintained and switched using the suction force of an electromagnetic plunger and the driving force of a motor, eliminating the need for manual operating force and simply pressing a switch. Tape recorders that can switch between various modes with extremely simple operations have been put into practical use.

In such automated tape recorders, various types of power mechanisms have been used to move driven members such as the head plate with the head mounted thereon and the change plate for channel changes to a predetermined mode position. It has been known. One method is to link a cam to an intermittent gear that intermittently meshes with the drive gear on the motor side, and this cam reciprocates the power plate to drive the driven member directly or through another driven member. There are things to do.

In this type of power mechanism, during a certain mode, the power plate is locked in a position where the intermittent part of the intermittent gear faces the drive gear, and the motor is rotated during execution of that mode. Also, the power plate does not move and the driven member does not move. When changing from that mode to another mode, the power plate is unlocked using an electromagnetic plunger or other means, the intermittent gear is engaged with the drive gear, and the rotating intermittent gear cam causes the power plate to reciprocate. H. The driven member that interlocks with this power plate is moved to the new mode position.

Incidentally, as such a power mechanism, for example, the one shown in FIG. 3 is known. In the same figure, as an example, a head lock plate 12 which is a driven member is engaged with the power plate 11, and by interlocking with the power plate 11, the head lock plate 12 is engaged with another driven member. A certain head plate (not shown) is moved. This head lock plate 12 is normally biased to the left in the figure (to the locking position or other mode side) by a biasing spring 13, and when a signal is received, the power plate 12 resists the biasing force.
1 allows it to move forward. This head lock plate 12 is provided with a locking protrusion 12a at its tip, and when the power plate 11 moves to the frontmost position, the locking portion 14a of the locking member 14 is At the point in time when it has crossed over and returned a little by the amount of overstroke, the locking portion 14a of the locking member 14 engages with the protrusion 12a, thereby locking. Therefore, the shape of the cam 15 that operates the power plate 11 via the roller 11a provided on the power plate 11 is likely to be configured so that the power plate 11 has an overstroke at its maximum diameter portion 15a. .

Furthermore, the power plate 11 is biased in its return direction by a spring 16, thereby causing the power plate 11 to
The upper roller 11a is pressed against the cam 15. Further, since there is an overstroke, the engagement point between the head lock plate 12 and the lock member 14 is a point where the roller 11a of the power plate 11 exceeds the maximum diameter portion 15a of the cam 15.

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

That is, when moving the power plate 11 forward with a motor,
Since the biasing force of the head lock plate 12 is applied to the motor, in order to reduce the load on the motor at that time, the distance between the cam 15 and the maximum diameter part 15a must be made into a gentle slope, and the distance between this (Towing distance of power plate 11)
inevitably becomes larger. As a result, the distance from the maximum diameter portion 15a (distance for returning the power plate 11) is relatively shortened, and during this period, the shape is steeply downward. Therefore, the power plate 11 is
When reaching the point beyond 5a, head lock plate 12
and the lock member 14 engage with each other, but in this case, the cam 15
Since the shape of the head lock plate 12 is steeply descending from the maximum diameter portion 15a toward the minimum diameter portion, the engagement point between the head lock plate 12 and the lock member 14 is biased by the biasing spring 13 of the head lock plate 12. In addition to the force, the return force of the spring 16 applied to the power plate 11 is applied at the same time.

In this case, since the springs 13 and 16 are instantaneously contracted from their fully extended states, the impact force applied to the engaging portions will be several times greater than when the power plate 11 is gradually returned to its original position. As a result, the durability of the locking member deteriorates considerably, posing a serious problem in terms of the performance of the tape recorder.

Further, such problems are not limited to the above-mentioned configuration, but also exist in, for example, a configuration in which the head plate is directly driven, a configuration in which the change plate is driven, and the like.

[Object of the Invention] The present invention was proposed in order to eliminate the drawbacks of the prior art as described above, and its purpose is to lock the driven member by improving the shape of the force arm. Load related to the lock member! ! It is an object of the present invention to provide a power mechanism for a tape recorder which reduces the power consumption of the tape recorder and improves its durability.

[Summary of the Invention] The power 1a structure of the tape recorder of the present invention has a cam provided in an intermittent gear, in which the surface from the maximum diameter part to the diameter part where the driven member is held by the lock member forms a gentle slope. With this configuration, the power plate returns extremely slowly until the locking member locks the driven member, so most of the return force of the power plate is applied to the locking member when locking the driven member. Therefore, the load on the lock member is reduced.

[Embodiment of the Invention] An embodiment to which the power mechanism of the tape recorder according to the present invention as described above is applied will be specifically described with reference to the drawings. The embodiment shown in FIGS. 1 and 2 engages a head lock plate as a driven member of the power plate,
This is a power mechanism in which the present invention is applied 3'Fi to a tape recorder configured to drive a head plate, which is another driven member, via this head lock plate.

As shown in Fig. 1, the intermittent gear 1 has an intermittent part 1a without gear teeth around it, and rotates clockwise in the figure when it meshes with the drive gear 2 that is interlocked with the motor. , 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,
A roller 4a of a power plate 4 is in contact with the outer periphery of this cam 3. The roller 4a 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 (to the left in the figure).

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, a lock diameter portion 3b where a head lock plate, which will be described later, engages with a lock member from the maximum diameter portion 3a.
It forms a long, gentle slope A. This slope A
After being slightly extended from the lock diameter portion 3b, it becomes 4+? 11 and connects to the smallest diameter part by descending at an inclined plane B.

As with the conventional type, a head lock plate 6 that is linked to a head plate (not shown) is engaged with the power plate 4, and this head lock plate 6 is normally moved toward the left in the figure (at the locking position) by a biasing spring 7. or another mode), and when a signal is received, the power plate 4 moves forward against the urging force.

A locking protrusion 6a is provided at the tip of the head lock plate 6, and when the head lock plate 6 moves to the frontmost position in conjunction with the power plate 4, this protrusion 6a locks the locking member 8. When the projection 6 is over the part 8a and has returned slightly by the amount of the overstroke, the protrusion 6
The lock portion 8a of the lock member 8 is engaged with the portion a.

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

That is, as shown in FIG. 1, when the intermittent portion 1a of the intermittent gear 1 faces the drive gear 2, the roller 4a of the power plate 4 is located at the small diameter portion of the cam 3, and the power plate 4 is moved by the spring 5. The head lock plate 6, which is interlocked with the plate 4, is also urged by a spring 7 and is in the return position (leftward in the figure). Further, since the head lock plate 6 is in the return position, its protrusion 6a is located at a rearward and distant position from the lock portion 8a of the lock member 8.

Then, in the state shown in FIG. 1, a signal is sent and a motor (not shown) is operated, so that the intermittent gear 1 and the cam 3 start rotating, and the operation of the cam 3 causes the power plate 4 and the head lock plate 6 starts moving forward against the biasing force of the respective springs 5.7.

As a result, as shown in Fig. 2, when the roller 4a of the power plate 4 reaches the maximum diameter part 3a of the cam 3, the power plate 4 and the head lock plate 6 move to the frontmost position (towards the right in the figure). At this point, the protrusion 6a of the head lock plate 6 has climbed over the lock portion 8a of the lock member 8.

When the roller 4a of the power plate 4 exceeds the maximum diameter portion 3a of the cam 3, the power plate 4 starts to return to the left in the figure by the biasing force of the spring 5 while being guided by the gentle slope A.

Then, the roller 4b moves slightly down the gentle slope A of the cam 3 to the lock diameter portion 3a, and when the power plate 4 returns by an amount corresponding to the overstroke, the lock member 8 is attached to the protrusion 6a of the head lock plate 6. The lock portion 8a is engaged, thereby locking the head lock plate 6.

In this case, since the roller 4a is guided by the gentle slope A of the cam 3, the power plate 4 and the head lock plate 6 are decelerated, and most of the biasing force of the return spring 5 applied to the power plate 4 is borne by the cam 3. Moreover, the biasing force of the spring 7 applied to the head lock plate 6 is not applied instantaneously.

Therefore, the impact force applied to the lock member 8 when locking the head lock brake 1-0 is extremely small compared to the conventional one, and the load on the lock member 8 is almost only the force of the return spring 5 of the power plate 4. The durability of the head lock plate 6 and the lock member 8 can be improved.

Note that after locking, the roller 4a of the power plate 4
descends the steep slope B of the cam 3, and finally, as shown in FIG. stops, and the power plate 4 is also fixed at the same position.

[Effects of the Invention] As explained above, according to the present invention, by making simple improvements to the shape of the cam, the load on the locking member that locks the driven member can be reduced and its durability can be improved. It is possible to provide a power mechanism for a tape recorder.

[Brief explanation of the drawing]

1 and 2 are plan views showing an embodiment of the power mechanism of a tape recorder according to the present invention, respectively. FIG. 1 shows the power plate in the return position, and FIG. 2 shows the power plate in the return position. FIG. 3 is a plan view showing an example of the power mechanism of a conventional tape recorder. DESCRIPTION OF SYMBOLS 1... Intermittent gear, 1a... Intermittent part, 2... Drive gear, 3... Cam, 3a... Maximum diameter part, 3b... Lock diameter part, 4... Power plate, 4a...Roller, 5, 7...Spring, 6...Head lock plate, 8...Lock member, A...Gentle slope, B
...A steeply sloped surface. Figure 1 i$2 Figure 3

Claims (1)

[Claims] (1) Equipped with an intermittent gear that is intermittently rotated by a drive gear and a power plate that reciprocates by the action of a cam provided on the intermittent gear, and the movement of this power plate moves the driven member to the play position or fast forward/rewind position. In a tape recorder power mechanism configured such that the driven member is held by a locking member after a certain stroke operation, the driven member is moved from the maximum diameter part of the cam provided on the intermittent gear to the locking member. A power mechanism for a tape recorder, characterized in that a surface up to a diameter portion held by the tape recorder is formed with a gentle slope.