JP2558349Y2 - Tuning knob - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuning knob, and more particularly to a tuning knob which is directly connected to a variable condenser shaft, and which performs a tuning operation by changing the capacity of the variable condenser by a rotation operation thereof.

[0002]

2. Description of the Related Art In a radio receiver, a cassette type tape recorder with a radio, and the like, a tuning operation is directly performed by a tuning knob directly connected to a variable condenser.
As shown in FIG. 5, such a tuning knob is provided with an arc-shaped opening 2 concentric with the center thereof, and a stopper pin 3 is received in the opening 2, thereby regulating the rotation angle. Like that. This means that if there is no stopper pin 3, the knob 1 will be rotated greatly,
This is because there is a possibility that the variable condenser may be damaged, and the variable condenser is protected by the stopper pin 3.

[0003]

The tuning knob provided with such an arc-shaped opening 2 for receiving the stopper pin 3 has its center of gravity adjusted by the presence of the opening 2.
Will be off center. Therefore, as shown in FIG. 5, there is no particular problem when stopping at the neutral position, but when stopping at the unbalanced position as shown in FIG. , And this rotation is transmitted to the variable condenser. Therefore, the frequency shifts and the tuning goes out of order.

The present invention has been made in view of such a problem, and is intended to prevent a tuning knob provided with an arc-shaped opening for receiving a stopper pin from rotating by itself and causing a frequency shift. It is intended to provide a knob.

[0005]

According to the present invention, a tuning knob directly connected to a shaft of a variable condenser and adapted to perform a tuning operation by rotating the same is formed with an arc-shaped opening extending in a circumferential direction. The rotation angle is regulated by inserting a stopper pin therein, and a balance weight portion for canceling the unbalance due to the opening and making the center of gravity substantially coincide with the center is provided.

[0006]

The unbalance due to the opening is canceled by the balance weight portion, and the center of gravity substantially coincides with the center. Therefore, no rotational moment is generated by the eccentric center of gravity at any rotational position, and the tuning knob does not rotate by an impact or the like.

[0007]

1 and 2 show a tuning device having a tuning knob according to an embodiment of the present invention. This tuning device constitutes, for example, a tuning device of a cassette type tape recorder with a radio. . The tuning device includes a tuning knob 10. A variable condenser 12 is mounted on the printed circuit board 11, and a rotating shaft 13 of the variable condenser 12 penetrates the printed circuit board 11 and protrudes to the opposite side, and is connected to the center of the tuning knob 10 by a screw 14. I have.

The tuning knob 10 has an operating portion 17 having irregularities on the outer periphery thereof, and is exposed to the outside through an opening 19 of a cabinet 18. A ring-shaped protrusion 20 is formed on the front side of the tuning knob 10, and triangular teeth 21 are formed on the outer periphery thereof. Then, a rack 23 provided with a pointer 22 at the distal end is engaged with the triangular teeth 21. A locking claw 24 is integrally connected to an end of the rack 23, and the locking claw 24 is locked by a locking portion 25 of the ring-shaped protrusion 20 of the knob 10. .

The tuning knob 10 has an arcuate opening 28 formed concentrically with the center thereof.
The opening 28 receives a stopper pin 29 protruding from the rear side of the cabinet 18 and integrally provided therewith. The tuning knob 10 has balance weight portions 30, 31 on the upper side and the lower side of the arc-shaped opening 28, respectively. The balance weight portions 30, 31 cancel the imbalance caused by the opening 28, and adjust the center of gravity. I try to match the center.

In the above-described configuration, by rotating the outer peripheral portion 17 of the tuning knob 10 through the opening 19 of the cabinet 18, the rotating shaft 13 of the variable condenser 12 is rotated. Such a rotating shaft 13
With the rotation of the variable condenser 12, the capacity of the variable condenser 12 changes, so that a broadcasting station of a desired frequency can be selected. Further, the rack 23 which engages with the triangular teeth 21 formed on the outer peripheral surface of the ring-shaped projection 20 of the knob 10 moves left and right in FIG. As a result, the pointer 22 moves on the dial display plate 33 to display the tuning frequency.

Further, the tuning knob 10 is provided with a stopper pin 2 provided integrally with the cabinet 18.
Since the knob 10 is provided with the arc-shaped opening 28, the rotation of the knob 10 beyond a predetermined angle prevents the stopper 2 from rotating.
9 to prevent the variable condenser 12 from being damaged.

Moreover, the imbalance caused by the provision of the opening 28 can be reduced by the balance weight portion 30,
The center of gravity of the knob 10 coincides with the center of the variable condenser 12 which is connected to the rotating shaft 13 because the knob is canceled by 31. Therefore, even if an external impact is applied, the knob 10 does not rotate due to the moment generated by the imbalance, and the frequency deviation can be reliably prevented. Therefore, even if the diameter of the knob 10 is increased, rotation due to the eccentricity of the center of gravity is eliminated, and the knob 10 having a large diameter can be used. Since the center of gravity coincides with the center of the knob 10, the knob 1
The operation force for the zero rotation is reduced, thereby improving the tuning operability.

FIG. 3 shows a modification. In this modification, the balance weight portion 30 is formed only on the outer peripheral side of the arc-shaped opening 28. FIG. 4 shows still another modified example. In this modified example, a balance weight portion 30 is formed on the outer peripheral side of the end face opposite to the ring-shaped projection 20 having the triangular teeth 21 on the outer peripheral portion. Like that. Also in these modified examples, since the center of gravity of the knob 10 can be made coincident with the center by the balance weight portion 30, the same operation and effect as the above-described embodiment can be achieved.

[0014]

As described above, according to the present invention, an arc-shaped opening extending in the circumferential direction is formed, and a stopper pin is inserted into this opening to regulate the rotation angle.
A balance weight portion for canceling the unbalance due to the opening and making the center of gravity substantially coincide with the center is provided. Therefore, even if an external impact is applied,
The tuning knob does not rotate on its own to cause a frequency shift. There is no problem even if the diameter of the knob is increased, and the size is not limited. Furthermore, since the center of gravity coincides with the center, the operating force for turning the knob is reduced,
Operability will be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a tuning device provided with a tuning knob according to an embodiment of the present invention.

FIG. 2 is a front view of the tuning device.

FIG. 3 is a front view of a tuning knob according to a modified example.

FIG. 4 is a rear view of a tuning knob of another modification.

FIG. 5 is a front view of a conventional tuning knob.

FIG. 6 is a front view of the tuning knob when stopped at a position shifted from the neutral position.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Knob 2 Arc opening 3 Stopper pin 10 Tuning knob 11 Printed circuit board 12 Variable condenser 13 Rotating shaft 14 Screw 17 Outer peripheral part 18 Cabinet 19 Opening 20 Ring-shaped protrusion 21 Triangular teeth 22 Pointer 23 Rack 24 Locking claw 25 Locking part 28 Arc opening 29 Stopper pin 30, 31 Balance weight part 33 Dial display plate

Claims (1)

(57) [Scope of request for utility model registration] 1. A tuning knob directly connected to a shaft of a variable condenser and adapted to perform a tuning operation by a rotation operation thereof, wherein an arc-shaped opening extending in a circumferential direction is formed, and a stopper pin is inserted into the opening. A tuning knob, wherein a rotation angle is regulated, and a balance weight portion for canceling imbalance due to the opening and substantially matching the center of gravity with the center is provided.