JPH021958Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a dial device for a radio receiver, and in particular, it is possible to set the rotation speed and diameter of a dial rotating shaft to predetermined values, and to improve tuning. The present invention relates to a device that can be applied even when the stroke of the dial rotating shaft is small.

(b) Prior art When a variable capacitor is used as a variable capacitance element in a conventional radio receiver, when the stroke of the dial rotating shaft provided in the receiver is small, the amount of movement of the dial rope wound around the rotating shaft In order to reduce the rotation speed, it is necessary to reduce the diameter R of the rotating shaft, thereby reducing the stroke l (=nπR) when the rotational speed is n. (π indicates pi.) However, in this case, if the rotation speed n is decreased, it becomes difficult to perform synchronization, and on the other hand, if the diameter is decreased, the dial rope wound around the rotation of the dial rotation shaft is The problem was that the coefficient of friction between the two wheels was not sufficient, resulting in slipping.

(c) Purpose of the invention This invention makes it possible to increase the number of rotations and the diameter of the dial rotating shaft even when the moving distance of the pointer during tuning operation in a radio receiver is short.
It is therefore an object of the present invention to provide a dial device that can smoothly perform tuning operations.

(d) Structure of the invention The invention consists of the first
, a dial rotation shaft, a second pulley, and a dial rope suspended from the variable capacitor adjustment shaft, the first pulley, the dial rotation shaft, and the second pulley; When each pulley is provided with a large diameter part and a small diameter part, and the diameters of the small diameter part and the large diameter part are respectively _{R 1} , r ₁ and R 2 , r ₂ , R ₂ /R ₁ = r ₂ /r ₁ is set. However, the rotation speed and diameter of the dial rotating shaft can be set to predetermined values.

(e) Examples The drawings all show the dial device of the present invention.
FIG. 1 is a perspective view of the device in which a dial rope is suspended from each component, and FIG. 2 is a plan view seen from the direction A in FIG. 1.

Next, the present invention will be explained according to the drawings. 1 is a dial rotating shaft, 2 is a first pulley having a small diameter part 3, a large diameter part 4, and a rope guide groove 5; 6 is a small diameter part 7, a large diameter part 8. and a second pulley having guide protrusions 9, 9, 10 is a dial rope, 11, 1
Reference numeral 1 denotes a small pulley, and all components except the dial rope are pivotally supported on a base 12 such as a chassis.

First, the method of suspending the dial rope 10 will be explained. After attaching one end of the coil spring 14 to the protruding piece 13 provided on the first pulley 2 and connecting the dial rope 10 to the other end, the coil spring 14 is attached to the tip of the dial rotating shaft 1 through the guide groove 5 of the first pulley 2. Wrap it multiple times (four times in the example in the drawing).

After that, the dial rope 10 that was wrapped around the large diameter part 8 of the second pulley 6 is wrapped around the protrusion 9, and further wrapped around the small diameter part 7 and then led out, and the small pulley 11, 1
1 to the coil spring 14 provided on the first pulley 2 .

Display portions B to C between the small pulleys 11 and 11
When the dial rotation shaft 1 is rotated clockwise, the second pulley 6 rotates clockwise, so the dial rope 10 moves from B to C, and along with this, the first pulley 2 rotates clockwise, and a variable condenser adjusting shaft (not shown) of the variable condenser coupled to the shaft hole of the first pulley 2 rotates clockwise.

On the other hand, if the dial rotation shaft 1 is rotated counterclockwise, it will rotate counterclockwise, contrary to the above.
Along with this, dial rope 1 in the display part
0 moves from C to B, and the tuned station can be displayed at a predetermined position, for example, by providing the dial pointer on the dial rope 10 and the indicator on the base side of the chassis or the like.

Here, as shown in Figure 2, the diameters of the small diameter parts 3 and 7 are
Assume that R ₁ and r ₁ are the diameters of the large diameter portions 4 and 8, R _{2 and} r 2 respectively, and the diameter of the dial rotating shaft 1 is R, and that the dial rotating shaft 1 is rotated n times.

At this time, the amount of movement of the dial rope 10, that is, the stroke l is l=nπR.

If this stroke l causes the first pulley 2 to rotate by an angle θ and the second pulley 6 to rotate by an angle θ ₁ , then the large diameter portion 4 of the first pulley 2
The amount of payout of the dial rope 10 is 2πR ₂ ×
θ/360, and the winding amount of the small diameter portion 3 is 2πR ₁ ×θ/360, while the winding amount of the dial rope 10 by the large diameter portion 8 of the second pulley 6 is 2πr ₂ ×θ1/360, or the small diameter The amount of feed by the portion 7 is 2πr ₁ ×θ1/360.

Furthermore, in order to compensate for the difference between the feeding amount and the winding amount at the first pulley 2 at the second pulley 6 , 2πR ₂ ×θ/360=2πr ₂ ×θ ₁ /360…(1) 2πR ₁ ×θ/360=2πr ₁ ×θ ₁ /360 …(2) must be satisfied.

Here, if we transform equation (1), θ ₁ = R ₂ θ/r ₂ , and
When formula (2) is transformed, θ ₁ = R ₁ θ/r ₁ , so R ₂ /r ₂ = R ₁ /r ₁ , that is, R ₂ /R ₁ = r ₂ /r ₁ holds true from both equations. If such conditions are satisfied, the difference between the amount of payout and the amount of winding of the first pulley can be compensated for by the second pulley.

And the dial rope 10 in the display part
As is clear from the above equation, the stroke (tuning stroke) is determined by the diameter of the large diameter part of each pulley and the diameter of the small diameter part, regardless of the diameter and rotation speed of the dial rotating shaft. The tuning stroke can be reduced by reducing the diameter of the small diameter portion under certain conditions.

By setting the aforementioned diameters R ₂ and r ₂ to large values, even in radio receivers with a small tuning stroke,
The rotation speed and diameter of the dial rotating shaft can be increased.

(f) Effect of the invention According to the invention, the diameters of the large diameter part and the small diameter part provided in the first pulley and the second pulley, respectively, are set to satisfy R ₂ /R ₁ = r ₂ /r ₁ . Since I set it to
Even if the movement distance of the pointer during the tuning operation is short, this can be handled by making the diameter of the small diameter portion small. However, since the diameter or rotational speed of the dial rotation shaft can be increased in this case, problems such as slips on the dial rotation shaft and difficulty in synchronization operations, which are conventional, do not occur.

[Brief explanation of the drawing]

The drawings all show the dial device of the present invention,
FIG. 1 is a perspective view of the main parts of the device, and FIG. 2 is a plan view seen from the direction A in FIG. 1. Explanation of main drawing numbers, 1...Dial rotation axis, 2 ...
...First pulley, 3,7...Small diameter part, 4,8...
...Large diameter part, 10...Dial rope, 14...Coil spring.

Claims (1)

[Scope of utility model registration request] a first pulley attached to a variable condenser adjustment shaft and having a large diameter part and a small diameter part; a dial rotation shaft; a second pulley having a large diameter part and a small diameter part; and a second pulley from the dial rotation shaft to the first pulley. a dial rope suspended to the dial rotating shaft through the large diameter part of the first pulley, the small diameter part of the second pulley, and the large diameter part of the second pulley; The respective diameters R ₁ and R ₂ of the small diameter part and large diameter part of the second pulley, and the respective diameters r ₁ of the small diameter part and large diameter part of the second pulley.
and r ₂ are set to R ₂ /R ₁ =r ₂ /r ₁ , and the rotation speed and diameter of the dial rotation shaft can be set to predetermined values.