JPH0412532B2 - - 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, and in particular, performance is improved by providing a cam brake device that achieves accurate and stable operation. It pertains to what was caused.

[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 the need for manual operating force. .

In such automated tape recorders, various types of power mechanisms have been known to move each member to a predetermined mode, but one of them is a cam mechanism attached to the drive gear on the motor side. There is a cam mechanism in which the driven member is driven by the cam mechanism. This type of power mechanism uses a locking member to lock the cam mechanism after it has moved a certain stroke, so that during a certain mode the cam mechanism does not operate and the driven member does not move. ing.

In addition, when changing from that mode to another mode, the cam mechanism is unlocked by an electromagnetic plunger or other means, and the cam mechanism is interlocked with the drive gear.
Operation of the cam mechanism moves the driven member to a new mode position.

By the way, in a tape recorder, the cam mechanism is configured to be locked in the middle of its operation, so when the cam mechanism is locked in the middle of its operation at the lock position, the load applied to the locking member is large, and the locking member cannot be locked. This may cause a decrease in the durability and performance of the component. Therefore, in this type of power mechanism, the cam mechanism is equipped with a brake device that applies frictional force using a leaf spring or the like, and by operating this brake device when the cam mechanism is locked, the operation of the cam mechanism is temporarily stopped or decelerated. As a structure for locking the cam mechanism, it is possible to reduce the load applied to the locking member.

[Problems with the Background Art] However, as described above, when a leaf spring is used as a brake device to press the surface of the cam mechanism and this pressing force applies a braking force to the cam mechanism, it is difficult to apply the brake to the cam mechanism. In addition to the lack of accuracy in the timing of releasing the leaf spring, the friction force of the brake varies significantly depending on the precision of the leaf spring and the condition of the brake surface, making it difficult to perform a consistent braking operation. Furthermore, in a leaf spring where the frictional force is unstable, in order to obtain a braking force above a certain level, the brake pressure of the leaf spring must be increased, but in this case, it is necessary to increase the braking pressure of the leaf spring, but in this case, it is necessary to increase the braking pressure of the leaf spring. This is also a problem as it leads to instability.

For this reason, there is a strong demand for a brake device that operates accurately.

[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 realize an accurate and stable braking device and improve the durability and performance of the locking member. It is an object of the present invention to provide a power mechanism for a tape recorder with improved performance.

[Summary of the Invention] The power mechanism of the tape recorder of the present invention employs a brake gear with a torque load as the brake device, and is configured to mesh with the drive gear that drives the cam mechanism, thereby achieving the following advantages: By meshing the brake gear with the drive gear at the position where you want to apply the brake, you can apply the brake to the cam mechanism at the correct position, and in order to apply a torque load to the rotating gear, you can set a constant torque value. As a result, stable braking operation is possible.

[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 2.

As shown in Fig. 1, a cam 1 and a cam drive gear 2 are attached to the top and bottom of the shaft so that they operate together.
It is configured to rotate around. A cam driven roller 4a attached to a driven member 4 is pressed into contact with this cam 1, and when this roller 4a crosses the maximum diameter part of the cam 1 and reaches the lock part of the cam 1, this roller 4a The cam 1 is locked via the driven member 4 by a locking member (not shown).

On the other hand, the cam driving gear 2 includes a gear portion 2a that meshes with a gear on the motor side (not shown), and an intermittent portion 2b that is disengaged from the gear on the motor side when the cam is locked. This intermittent part 2b
A brake side meshing gear 5 of a certain length is attached in front of the brake side.

On the other hand, a brake gear 6 is mounted on the same plane as this brake side meshing gear 5, and this brake gear 6 is pressed downward by a spring 7 and a slip ring 8, and the shaft 9 of the gear 6 is A constant torque value is set by crimping the flange portion 9a provided at the lower end of the flange portion 9a.

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

That is, the driving gear 2 rotates in response to the rotational force of the gear on the motor side, and accordingly the cam 1 is operated to move the roller 4a and the driven member attached to the roller 4a. Before the driven member reaches a predetermined position and the cam 1 is locked by a locking member (not shown), the brake-side meshing gear 5 provided in front of the intermittent portion 2b meshes with the brake gear 6. A brake force is applied from the brake gear 6 to the meshing gear 5, thereby decelerating the cam drive gear 2 and the cam 1.

At this time, the braking force applied to the cam 1 via the meshing gear 5 is obtained as a constant braking force depending on the length of the brake-side meshing gear 5 and the torque value of the brake gear 6. In this case, depending on the selection of the spring 7, the brake gear 6
Setting of the torque value to be given to can be easily and accurately performed. Further, by selecting the position of the end of the meshing gear 5, the start and end positions of the braking operation can also be set accurately. Therefore, there is no inconvenience that the braking force becomes unstable, and there is no instability in operation such as surface wobbling of the cam, which is the case with a structure in which a leaf spring with high braking pressure is crimped onto the cam, resulting in stable braking. Able to perform movements.

After the cam 1 is decelerated to a constant speed by this braking operation, it is locked by a locking member (not shown), so the load on the locking member is significantly reduced and kept constant, increasing the durability of the locking member. and performance can be improved. At this time, the cam drive gear 2 connects the intermittent portion 2b to the brake gear 6.
to face.

Note that the present invention is not limited to the above-mentioned embodiments, and for example, a configuration can be considered in which a torque value is given to the brake gear by sandwiching an elastic synthetic resin between the brake gear and its shaft. .

[Effects of the Invention] As explained above, according to the present invention, by realizing an accurate and stable cam brake device, it is possible to provide a power mechanism for a tape recorder in which the durability and performance of the locking member are improved.

[Brief explanation of drawings]

1 and 2 are a sectional view and a plan view, respectively, showing an embodiment of a power mechanism of a tape recorder according to the present invention. 1...Cam, 2...Cam drive gear, 2a...
Gear part for meshing with the gear on the motor side, 2b...
Intermittent portion, 3... shaft, 4... driven member, 4a...
Roller, 5... Brake side meshing gear, 6...
Brake gear, 7...spring, 8...slip spring, 9...shaft, 9a...flange portion.

Claims (1)

[Claims] 1. In a tape player power mechanism in which a cam 1 is provided on a drive gear 2 that rotates in mesh with a motor side gear, and a driven member 4 is moved by the cam, the drive gear 2 has the following features: , a gear portion 2a that meshes with the motor side gear, and an intermittent portion 2b that disengages from the motor side gear are formed, and the rotation of the drive gear 2 is locked with the motor side gear facing the intermittent portion 2b. A brake gear 6 with a constant torque load is arranged near the drive gear 2, and the drive gear 2 has a brake-side meshing gear that meshes with the brake gear 6 before the drive gear 2 is locked. A power mechanism for a tape player, characterized in that a gear 5 is integrally provided with dimensions corresponding to a stroke for applying a brake to a drive gear 2. 2. The power mechanism for a tape recorder according to claim 1, wherein the brake gear has its torque load applied by a brake member consisting of a spring and a slip ring.