JPS5922096B2 - Speed increaser - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed increasing device suitable for a tape fast forwarding device of a tape recorder or the like.

Conventionally, tape fast forwarding in, for example, an 8-track tape recorder has been accomplished by changing the rotational speed of the motor or by changing the belt hooking in the belt transmission mechanism from the motor to the capstan shaft.

However, in the former case, the high-speed motor is expensive, so the tape recorder itself is expensive, and in the latter case, the configuration is complicated.

It is an object of the present invention to provide a speed increasing device which eliminates the above-mentioned drawbacks and which can be used not only for tape recorders but also as a general rotational speed switching device.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a motor shaft of a motor that is a drive source, and a drive gear 2 that is a first rotating body is mounted on this motor shaft 1 .

The boss portion 3 of the drive gear 2 has a step in the middle so that the tip side has a small diameter, and a driven gear 4, which is a second rotating body, is attached to the small diameter portion.
The boss portion 5 is rotatably mounted.

This driven gear 4 has a smaller diameter than the drive gear 2 and has a substantially cylindrical pulley part 6 around its boss part 5, and this pulley part 6 is connected to a predetermined operating part (not shown) via an endless belt 7. For example, in the case of a tape recorder, it is connected to a pulley mounted on a capstan shaft.

The outer diameter of the large diameter portion of the boss portion 30 of the drive gear 2 and the outer diameter of the boss portion 5 of the driven gear 4 are approximately the same size, and a coil spring 8 is wound around the outer peripheral surfaces of both. There is.

The coil spring 8 functions as a one-way joint, and its diameter decreases as the drive gear rotates 20 times, presses against the outer periphery of the boss portion 5 of the driven gear 4, and rotates the driven gear 4 together with the drive gear 2. let

On the other hand, 9 in the figure is an intermediate rotating body, and this intermediate rotating body 9 is the shaft 1.
It is rotatably supported by one end of a rotating arm 11 that is rotatably provided around zero.

A large gear 12 is formed at the upper part of the intermediate rotary body 9, and a small gear 13 is formed at the lower part.

Note that the driving gear 2, driven gear 4, large gear 12, and small gear 13 are all formed in the same module.

The other end of the rotating arm 11 is connected to one end of a rotatably provided L-shaped operating lever 15 via a connecting rod 14, and is interlocked with the operating lever 15 when the operating lever 15 is rotated in the vertical direction. The rotating arm 11 is configured to rotate in the horizontal direction.

The operating lever 15 is rotationally biased in one direction by a return spring 16, and the operating lever 15 is rotated in the opposite direction (direction of arrow a) by gripping a knob 17 attached to the other end of the operating lever 15. By moving, the rotating arm rotates in the direction indicated by the arrow, so that the intermediate rotating body 90 and the dog gear 12 mesh with the driven gear 4, and the pinion gear 13 meshes with the driving gear 2 at the same time. .

Note that 18 in the figure is a stopper that restricts the amount of rotation of the operating lever 150 in the opposite direction.

The operating lever 15 is, for example, an operating lever for fast forwarding the tape in a tape recorder.

In the speed increasing device configured as above, when the motor is started, the motor shaft 1 and the driving gear 2 rotate, and the driven gear 4 is integrated with the driving gear 2 by the action of the spring 80 as a one-way joint. That is, it rotates at the same rotation speed as the motor shaft 1.

Next, when the knob 17 is rotated in the direction of arrow a against the spring 16 to engage the large gear 12 and small gear 13 of the intermediate rotating body 9 with the driven gear 4 and the driving gear 2, respectively,
The driven gear 4 begins to rotate at high speed.

That is, the number of teeth of each of the drive gear 2, small gear 13, large gear 12, and driven gear 4 is z1! Z2. Z3. z4, the number of revolutions of the driven gear 40 n4 is obtained by the following formula (where nl is the number of revolutions of the driving gear 20, that is, the number of revolutions of the motor shaft 10).

), and zl>z4. Since Z2<Z3, n4>nl, that is, the driven gear 4 rotates at a higher speed than the motor shaft 1.

In this case, the spring 8 loses its ability to connect the drive gear 2 and the driven gear 4.

Therefore, by attaching this speed increasing device to an 8-track tape recorder and passing the endless belt 1 between the pulley mounted on the capstan shaft and the pulley section 6,
The capstan shaft rotates at a steady speed when the intermediate rotating body 9 is located away from the drive gear 2 and the driven gear 4, and the magnetic tape runs at a steady speed.

Then, rotate the knob 17 in the direction of arrow a, and rotate the rotation lever 1.
1 in the direction of the arrow so that the large gear 12 meshes with the driven gear 4 and the small gear 13 meshes with the driving gear 2, the capstan shaft rotates at high speed and the magnetic tape can be rapidly forwarded. can.

Therefore, according to the embodiment described above, the rotational speed of the driven gear 40, which is the second rotating body, can be switched between two stages by simply operating the lever without changing the rotational speed of the motor.

Note that this invention is not limited to the above embodiments,
For example, pulleys may be used instead of gears as the first and second rotating bodies and the intermediate rotating body.

Furthermore, this speed increasing device can be used not only for tape recorders but also for a wide range of general rotational speed switching devices.

As described in detail above, according to this invention, it is possible to provide a speed increasing device that is inexpensive, has a simple configuration, and can be widely used as a general rotational speed switching device.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of this invention, and FIG. 2 is a perspective view of the same embodiment. 2... Drive gear (first rotating body), 4...
... Driven gear (second rotating body), 8... Spring (one-way joint), 9... Intermediate rotating body.

Claims (1)

[Claims] 1. An eighth rotating body that is rotationally driven by a drive source, a second rotating body that is provided coaxially with the first rotating body and that operates a predetermined operating part, and a second rotating body that is always interposed between the two rotating bodies. 1st
a one-way joint that transmits rotational force from the rotating body to the second rotating body; and an intermediate rotation that is selectively interposed between the two rotating bodies and rotates the second rotating body at a higher speed than the first rotating body. A speed increasing device characterized by comprising a body.