JPS624922Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of the operation mechanism of a tape recorder, and particularly relates to a shock noise prevention mechanism for suppressing the shock noise of the mechanism when transitioning from a stopped state to a recording state. .

In a so-called built-in microphone type tape recorder, care must be taken to prevent noise from rotating parts etc. from being transmitted to the microphone during recording. However, many of these types of tape recorders use the rotation of a motor to move the recording head, so the rotating gear must be stopped the moment the recording head moves to the recording position. It was difficult to avoid the instantaneous mechanical impact noise generated within the mechanism.

The purpose of this invention is to provide a shock noise prevention mechanism that uses a simple mechanism to avoid mechanical impact sounds such as those described above and prevents noise from being transmitted to a microphone.

Examples of this invention will be described below with reference to the drawings.

1 and 2 are structural diagrams of a recording head operating mechanism to which a shock noise prevention mechanism according to an embodiment of the present invention is applied, with FIG. 1 showing the stop mode and FIG. 2 showing the recording mode.

In FIG. 1, 1 is a main board consisting of a chassis, 2 is a recording head, and this recording head 2 is integrally fixed to a slide plate 3 that slides in the direction of arrow A or B by a guide member (not shown). has been done. The mounting position of this slide plate 3 is appropriately set so that when it slides in the direction of arrow A, the magnetic head 2 comes into contact with the magnetic tape 4, and when it slides in the direction of arrow B, it separates from the magnetic tape 4. Spring 5 hung between main board 1
Therefore, it is always biased in the direction of arrow A. 6
A driving gear is connected to a motor (not shown) via a reduction gear, and is constantly rotated in the direction of arrow C around a shaft 1a provided on the main board 1. Reference numeral 7 denotes a partially toothed gear which rotates in the direction of arrow D only when meshing with the drive gear 6 about a shaft 1b provided on the main board 1, and a cam for moving the slide plate 3 coaxially. 7a, and has a starting shaft 7b against which a spring 8 for starting the rotation of the partially toothed gear comes into contact, and a locking piece 7c for stopping the rotation of the partially toothed gear and locking it at a predetermined position. The starting spring 8 has its coil center supported by a support shaft 1c provided on the main board, one arm 8a is supported by a support shaft 1d provided on the main board, and the other arm 8b is supported by a support shaft 1d provided on the main board. As described above, the springs are in pressure contact with the starting shaft 7b, and the elastic force of the springs applies rotational torque in the direction of arrow D to the partially toothed gear 7. In the stop mode shown in FIG. 1, the mounting position of the locking means, which will be described later, is determined so that the drive gear 6 is in the position just before it meshes with the gear portion of the partially toothed gear 7. Since rotational torque in the direction of arrow D is applied to the partially toothed gear 7, when the partially toothed gear is unlocked, the preliminary rotation of the partially toothed gear is caused by the rotational torque until it meshes with the drive gear 6. A rotation will take place.

9 is a driven lever that follows the rotation of the cam 7a;
By the support shaft 1e provided on the main board, the arrow E
Or it is supported so that it can swing freely in the F direction,
Its center portion contacts the cam 7a, and its tip contacts the back surface of the slide plate 3. 10 is a locking lever for locking the partially toothed gear 7 by engaging with the locking piece 7c; a first locking portion 10a for locking the partially toothed gear 7 in the stop mode; A second locking portion 10b for locking, and an arm 10 that rotates these locking portions in the direction of arrow G or H around a support shaft 1f provided on the main board.
c, and is normally applied with a rotational force in the direction of arrow G by a return spring 11. Further, the locking portions 10a and 10b have different structures, the former having a claw-like shape, and the latter having an elastic structure that absorbs external force by forming a constriction 10d.

The tip of the operating lever 12 is vertically opposed to the back of the arm 10c of the locking lever 10.
This operating lever 12 is structured to be guided and slid in the direction of arrow I or J by a guide shaft 1g provided on the main board, and is normally biased in the direction of arrow J by a return spring 13. .

Note that the toothless gear 7, the locking lever 10, and the locking piece 7c are connected to the locking portion 10a in the stop mode.
In the recording mode, the locking piece 7c engages with the locking portion 10b and the driving gear 6 and the toothless gear 7 are engaged, and in the recording mode, the locking piece 7c engages with the locking portion 10b and the driving gear 6 The positional relationship of each element, the length of the toothless portion, etc. are appropriately determined so as to form a state immediately after the toothless gear 7 has finished meshing.

Next, the operation of the recording head moving mechanism constructed as described above will be explained.

In the stop mode shown in FIG. 1, when the operating lever 12 is pressed in the direction of arrow I, the tip of the lever 12 presses the arm 10c. Therefore, the locking lever 10 rotates in the direction of arrow H around the support shaft 1f. In this case, once the operating lever 12 is pressed to a predetermined position, the operating lever 12 is locked by a lock lever (not shown), so that it will not return to its original state even if the pressing is stopped. In other words, the pressed state is maintained.

On the other hand, the locking lever 10 that moves in response to the operating lever 12 releases the engagement with the locking piece 7c by rotating by a predetermined angle, so the partially toothed gear 7 is moved by the force of the spring 8. Perform a preliminary rotation. When the drive gear 6 and the partially toothed gear 7 mesh with each other, the partially toothed gear 7 rotates in the direction of arrow D by the rotational force from the motor. As the partially toothed gear 7 rotates, the coaxially connected cam 7a also begins to rotate, and the driven lever 9 rotates in the direction of arrow E according to the peripheral shape of the cam 7a. Therefore, the slide plate 3 slides in the direction of arrow B against the spring 5 to bring the recording head 2 into contact with the magnetic tape 4. The recording head 2 is moved by such an operation.

In this case, the rotation transmission force to the partially toothed gear 7 is lost when the engagement between the gear part of the partially toothed gear 7 and the drive gear 6 is completed, but at the time of this termination, the apex of the cam 7a is connected to the driven lever 9. Since the contact point with the cam 7a has been exceeded, the cam 7a tends to continue rotating due to the pressing force of the driven lever 9 (the reaction force applied to the cam 7a in an open contact manner by the spring 5). However, immediately after this, the locking piece 7c engages with the locking portion 10b of the locking lever 10, and the rotation of the cam 7a,
In other words, since the rotation of the partially toothed gear 7 is forcibly stopped, the operation of the driven lever 9 is stopped. The state shown in FIG. 2 is the state when the rotation of the partially toothed gear 7 has stopped in this way, and shows that the head surface of the recording head 2 is in the recording mode in which it is in stable contact with the magnetic tape 4. ing.

By the way, as is clear from the above explanation, when the rotation of the partially toothed gear 7 is forcibly stopped by the locking lever 10, in more detail, the locking piece 7c provided on the partially toothed gear 7 is stopped. When engaging the second locking portion 10b of the locking lever 10, a relatively large force acts on the locking portion 10b. However, in this embodiment, since the constriction 10d is formed in the locking portion 10b, the entire locking portion acts elastically and stops the rotation of the partially toothed gear while absorbing the above-mentioned large force. Therefore, the force applied to the locking portion 10d when the rotation is stopped does not become an impact force, but is absorbed while being buffered, thereby reducing the generation of impact noise. That is, in the state where it is already electrically in recording mode,
Recording of mechanical impact sounds can be reduced or eliminated. In such devices, as in many tape recorders, the completion of the electrical recording mode precedes the completion of the mechanical recording mode.
By providing the shock noise prevention mechanism as described above, recording of impact sounds can be easily prevented. In addition, if there is no problem with accuracy, constriction 1
0d width and length, or the material of the locking lever 10,
By appropriately changing the material thickness, etc., and reducing the elastic constant of the locking portion 10b, the partially toothed gear 7 can be stopped even more smoothly, thereby completely eliminating impact noise.

To shift from the recording mode shown in FIG. 2 to the first stop mode, it is sufficient to operate a lock release lever (not shown) to release the locked state of the operation lever 12. That is, by this release operation, the operating lever 1
2 is returned in the direction of arrow J by the action of the return spring 13, and in conjunction with this, the locking lever 10 is rotated in the direction of arrow G by the action of the spring 11, so that the locking portion 10b and the locking piece 7c are not engaged. The connection is canceled. Then, since the driven lever 9 is pressing the cam 7a, rotational torque is generated in the cam 7a, and the partially toothed gear 7 rotates in the direction of arrow D, and the drive gear 6 and partially toothed gear 7 are engaged in a state just before they mesh. The stopper piece 7c and the first locking portion 10a are engaged and stopped. That is, the state returns to the stop mode shown in FIG. Note that even if an impact sound is generated when the locking piece 7c and the engaging portion 10a are engaged at this time, the impact sound has already shifted from the recording mode to the stop mode, so the impact sound will not cause trouble. will not occur. What is needed is to reduce or eliminate the recording of shot noise.
There is no need for this first engaging portion 10a to have an elastic structure.

Furthermore, in the embodiments described above, the engaging portion 10b has an elastic structure by forming the constriction 10d, but there are many more embodiments that can provide the necessary elastic force to this portion. For example, as shown in FIG. 3, similar effects can be obtained by attaching an elastic material 10e such as rubber to the locking portion 10b.
Furthermore, in this way, the locking portion 10b is not made of an elastic structure,
It goes without saying that the locking piece 7c may have an elastic structure.

As described above, according to this invention, since the relatively large force that acts when the recording mode is completed is buffered using elastic force, shock noise can be reduced or eliminated, and the tape recorder's Recording performance can be improved. Furthermore, since the structure is simple, miniaturization is not hindered, and the soundproofing means between the built-in microphone can be simplified, which has the advantage of reducing costs.

[Brief explanation of the drawing]

1 and 2 are structural diagrams of a recording head operating mechanism to which a shock noise prevention mechanism according to an embodiment of the present invention is applied, with FIG. 1 showing the stop mode and FIG. 2 showing the recording mode. FIG. 3 is a structural diagram of a recording head operating mechanism to which the shock noise prevention mechanism of another embodiment is applied, and shows the state in recording mode. 2... Recording head, 6... Drive gear, 7... Gear with missing teeth, 7a... Cam, 7c... Locking piece, 9...
Driven lever, 10... Locking lever, 10a... First locking part, 10b... Second locking part (locking part in recording mode), 10d... Constriction, 10e...
Elastic body, 12... Recording operation lever.

Claims (1)

[Scope of Claim for Utility Model Registration] A drive gear connected to a motor, a partially toothed gear that meshes with the gear and has a cam coaxially connected to it, and a driven lever that moves the recording head while following the rotation of the cam; It has a locking means for locking the toothless gear at a predetermined rotational position corresponding to a recording mode and a stop mode, and the locking means is connected to a locking piece provided on the toothless gear and a recording operation lever. A tape recorder comprising a locking lever, characterized in that the locking piece or the locking portion of the locking lever in the recording mode has an elastic structure that reduces impact force. Shock noise prevention mechanism.