JPH0760540B2 - Operating device for two pinch rollers of a recording and reproducing device having a reversing mechanism - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus having a reverse mechanism, in particular, an operating device for two pinch rollers of a cassette recorder, each one pinch roller being applied to a capstan. It relates to a type in which a spring and an operating member are assigned to each pinch roller in order to attach or separate from the capstan.

2. Description of the Related Art In a cassette recorder, it is known to provide a capstan that rotates at a constant speed in order to obtain stable tape running characteristics during recording and playback. The magnetic tape is applied to the capstan by a pinch roller,
This causes the magnetic tape to pass through the recording / playback head at a constant speed.

When the cassette recorder is switched from a regenerative run to another run, eg fast forward, the pinch rollers are pulled away from the capstan against the forces acting in the direction towards the capstan. For a cassette recorder having a reverse mechanism, two capstans and two pinch rollers are provided to use two recording / playback directions.

In the operating device provided for such a purpose, a mechanism unique to each capstan or each pinch roller is provided, and it is known to dispose one spring for each pinch roller.

During operation, that is, when the pinch roller is applied to the capstan, the pinch roller is subjected to a spring force that applies a pressing force. Therefore, a relatively large acting force is required to separate the pinch roller from the capstan. Because on the one hand, the pressing force of the spring must be overcome,
On the other hand, it is necessary to separate the pinch roller from the capstan against the pressing force.

The problem to be solved by the invention In practice, the required large switching force, which is provided in a known manner via a switching transmission, has proven to be disadvantageous. In a cassette recorder having a reverse mechanism, when the tape reaches the end in one direction, it is automatically switched to the other direction, but at this time, it is necessary to pull one pinch roller away from the capstan, and for this other direction. The other working pinch roller must be brought into its working position.

The large force exerted by the switching gear easily causes a wear phenomenon after long-term use, which has a considerable adverse effect on the smooth operating characteristics of the gear. Consequently, the switching speed when reaching the end of the tape is adversely affected. At this time, the reproduction switching process in the new tape running direction becomes long enough to be inconvenient for the user of the cassette recorder.

Such drawbacks can be avoided if they are designed with the extra expense and corresponding design to maintain smooth operation under high forces, but such measures are, of course, costly.

Therefore, an object of the present invention is to provide an operating device capable of operating a pinch roller in a recording / reproducing device having a reverse mechanism with a slight force, and capable of avoiding the above drawbacks. is there.

Means for Solving the Problems According to the present invention which solves the above problems, the operating member is
Lever levers that are formed by a reverse slider common to the two pinch rollers and that are respectively attached to the pinch rollers that are pivotally supported about the pivot center point and that form one side of each pressing triangular mechanism, It is adapted to be moved by both ends of the reverse slider, and a pressing spring is provided between a lever arm forming one side of each of the pressing triangles and an end of the reverse slider which is assigned to the lever arm. It is fixed and the pressure spring biases the lever arms towards the reverse sliders, and these lever arms are supported at each end of the reverse slider in the neutral position of the reverse slider, whereby the entire slide of the reverse slider is slid. Part of the movement is now done without force, while the other is being applied to the capstan. Lever arm of Nchirora is provided at a distance (A) from one end of the reverse slider, the lever arm of the other of the pinch roller is supported at the other end of the reverse slider thereto.

Function The basic idea of the present invention is to fix the pinch roller to a common reverse slider and to bring it to the stop position when the other pinch roller is pulled away from the capstan, in the stop position (pulled position). The point is that the force of one pinch roller is used. Therefore, during the switching process the two springs are at least partially assisted,
Switching work can be performed with a small amount of force.

In the known actuating device, the acting force for pulling one of the pinch rollers away from the capstan is greater than the crimping force of the spring, whereas in the present invention the switching is effected by the mutual assistance of the two springs. It can be done with little force.

The reduction in force obtained by the present invention not only allows for smooth actuation of the switching transmission in the desired manner, but also
Rather, it significantly increases the service life and operational reliability of the operating device.

Example Next, the configuration of the present invention will be specifically described with reference to the example shown in the drawings.

The operating device, generally designated by the reference numeral 10, is part of an unillustrated cassette recorder having a chassis 12. A guide 14 is fixed to the chassis 12, and a reverse slider 16 is horizontally movably guided in the guide 14 (see arrow B).

The cassette recorder equipped with a reverse mechanism further comprises, in a known manner, two capstans 18,20 with associated pinch rollers 22,24. One pinch roller 22
A pushing triangle mechanism with two lever arms 26, 28 is used to operate the. Two lever arms 26,2
The vertical angle 8 is rotatably supported at the turning center point 30. Correspondingly, the two lever arms 32, 34 form a pushing triangle mechanism for the other pinch roller 24, which is rotatably supported at the pivot point 36. A spring 38 is assigned to one of the pinch rollers 22. This spring 38
Is a spring holding member 40 arranged on the reverse slider 16.
It extends between the (point of action) and the upper end of the lever arm 26. Similarly, the other pinch roller 24 has a spring 42. The spring 42 is fixed to the spring holding member 44 (point of action) of the reverse slider 16 at one end and is fixed to the lever arm 32 at the other end.

At one position of the reverse slider 16 shown in FIG. 1, the pinch roller 22 is in its working position. That is, pinch rollers
22 is the capstan 18 due to the spring force of the tensioned spring 38.
Is pressed against. At this time, the upper end of the lever arm 26 keeps a distance A from the left end of the reverse slider 16.

At the same time, the other pinch roller 24 is separated from the capstan 20 by the lever arm 32 abutting against and being supported by the other right end of the reverse slider 16. At this time, the residual force of the spring 42 (like the spring 38), which acts as a tension spring on the lever arm 32, is supported by the reverse slider 16. This ensures that no external forces act on the entire system.

At the time of reverse switching, the reverse slider 16 moves in the direction of arrow B, that is, to the position shown by the alternate long and short dash line on the left side in FIG.

At this time, in the spring 38, the lever arm 26 has a reverse slider.
Abutting the ends of 16, the residual force of spring 38 is relaxed until it is supported here. Reverse slider 16 has springs 38,4
Pinch roller 24 without being affected by the spring force of 2
In the direction of arrow B until the first contact with the capstan 20
It is further moved to the position shown by the broken line in the figure.

The reverse slider 16 then goes a little too far (under a certain force), which causes a gap between the right end of the reverse slider 16 and the lever arm 32 (comparable to the spacing indicated by A in FIG. 1). A working intermediate chamber is formed, and the spring force of the spring 42 acts on the pinch roller 24, and the pinch roller 24 is applied to the capstan 20.

According to the switching work process at the time of reverse switching, at least a part of the total movement stroke of the reverse slider 16 is performed completely without external force, and during the switching work process, the two springs 38 and 42 are used. It is clear that, with the aid of this, the entire switching process takes place with relatively little force.

An important advantage as described above is that the pressing force for the rubber rollers 22 and 24 is generated by a spring which is tensioned between each lever arm 26 or 32 and the reverse slider 16,
It is obtained by supporting the lever arm (lever arm 32 in FIG. 1) separated from the capstan in each case by the reverse slider 16.

In the known device, when the pinch roller is pulled away from the capstan, the spring is largely displaced so that a force larger than the spring force has to be applied. Increased power is avoided.

Since the operating device 10 of the present invention requires relatively little force, the switching speed is relatively high. As a result, the pinch roller 22 or 24 is pressed against the capstan 18 or 20 for a short time when the traveling mechanism is stopped, whereby a "dent" or an indent is formed on the surface of the pinch roller 22 or 24 in the stopped state. Things can be avoided.

The operating device 10 of the present invention has further advantages.
That is, when the reverse slider 16 is unlocked, the spring 38
A force balance is formed between and 42 (see FIG. 2). The reverse slider "swings" to a neutral intermediate position, at which time the two pinch rollers 22,24 are pulled away from the capstans 18,20. This condition, which is technically called "pinch roller release", is important for the following reasons. In other words, this causes the two pinch rollers 22 and 24 to be unloaded, and the pressure causes the capstan 1
As it does not come into contact with the 8 and 20, the pinch roller 2
The risk of indentation on the surface of 2,24 is avoided.

The principle of the invention can also be realized by providing a pressure spring or a flexure spring instead of the tension spring used in the illustrated embodiment.

Advantageous Effects of the Invention According to the present invention, it is possible to operate the pinch rollers with a force smaller than the pressing force for pressing the respective pinch roller against the capstan by a simple mechanical means without requiring additional cost. You can As a result, the switching transmission can be constructed inexpensively and smoothly so that a reliable switching operation can be maintained. Moreover, the service life has been significantly increased.

[Brief description of drawings]

FIG. 1 is a schematic view of an operating device according to one embodiment of the invention in one possible operating position, and FIG. 2 shows the operating device shown in FIG. 1 in a neutral position in which no pinch rollers are in operation. FIG. 10 …… Operating device, 12 …… Chassis, 14 …… Guide, 16…
… Reverse slider, 18,20 …… Kyapstan, 22,24…
… Pinch rollers, 26,28 …… Lever arm, 30 …… Turning center point, 32,34 …… Lever arm, 36 …… Turning center point, 3
8 ... Spring as pressing spring, 40 ... Spring holding member, 42
...... Spring, 44 …… Spring holding member

Claims (4)

[Claims] 1. An operating device for two pinch rollers (22, 24) of a recording and reproducing device having a reverse mechanism,
Apply one pinch roller (22,24) to the capstan (18,20) or the capstan (18,2)
0) in which the springs (38, 42) and the operating member are arranged on each pinch roller (22, 24), the operating member includes two pinch rollers (22, 24). , Which are formed by a common reverse slider (16), are attached to each pinch roller (22, 24) that is pivotally supported about the pivot center point (30, 36) Lever arm that forms one side of the mechanism (26,3
2) is adapted to be moved by both ends of the reverse slider (16), and the lever arm (26, 3 forming one side of each of the pressing triangles).
2) and a pressing spring (38, 42) is fixed between the lever arm (26, 32) and the end of the reverse slider (16), the pressing spring (38, 42) Urges the lever arms (26, 32) toward the reverse slider (16), and these lever arms (26, 32) move the end portions of the reverse slider (16) at the neutral position of the reverse slider (16). The reverse arm (16) is supported on the capstan (18) so that a part of the entire sliding movement of the reverse slider (16) can be performed without force. (26) maintains a space (A) from one end of the reverse slider (16), while the lever arm (32) of the other pinch roller (24) has the other end of the reverse slider (16). Reverse, characterized by being supported at the end of An operating device for two pinch rollers of a recording / playback device having a mechanism. 2. An operating device according to claim 1, wherein the springs (38, 42) are tension springs. 3. The operating device according to claim 1, wherein the reverse slider (16) is locked at two end positions. 4. The operating device as claimed in claim 1, wherein the pinch rollers (22; 24) are made of rubber.