JPS60217720A - Dial device - Google Patents

Abstract

PURPOSE:To prevent destruction of a dial drive part by inserting a shaft of a tuning knob to the inner face of a tuning shaft so as to slip between the tuning shaft and the tuning knob when a prescribed value of a torque or over is applied between them. CONSTITUTION:Bearings 6-2, 6-4 by which shafts 8-4, 8-5 of the tuning knob 8 are fitted to the tuning shaft 6 are provided and slits are formed to the bearing 6-2 so as to allow the 6-2 to be deformed in radial direction. A coil spring 9 is inserted with pressing to the peripheral part and when a torque being a prescribed value or over is applied between the tuning shaft 6 and the tuning knob 8, they are turned relatively. When the variable capacitor shaft 4-1 is turned fully to the right or left, the variable capacitor shaft 4-1 contacts the stopper in the inside of the variable capacitor, the tuning shaft 6 stops turning and when the tuning knob 8 is turned further, the tuning knob 8 and the tuning shaft are slipped together. Thus, the destruction of the dial drive part is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a dial drive device for audio equipment such as a radio receiver or a player with a radio receiver.

Conventional configuration and its problems Conventionally, the operating section of a dial device is as shown in Fig. 1.
By fitting the bearing part 8-1 of the tuning knob 8 to the tuning shaft 6 and fitting the coil spring 9 there,
When the tuning shaft 6 and the tuning knob 8 are pressed together, and a torque above a certain level is applied between the tuning knob 8 and the tuning shaft 6,
It was configured to slip and rotate between them, preventing damage to the dial drive unit.

However, in the above device, a slit 8-2 is provided at the fitting portion of the tuning shaft 6 and the tuning knob 8 so that the tuning knob 8 can be deformed.
The surface of the tuning shaft 6 is easily damaged at a part of the corner 1, and the slip torque is unstable. Since the tuning knob 8 is an exterior part, it is often plated with resin, but the variation in torque on the spot is particularly large.When the knob is plated with 0 or sulfur resin, as shown in Figure 1, the bearing part 8-1 Both the plating variation on the inner surface and the plating variation on the outer periphery affect the torque value, which is undesirable. In addition, the coil spring 9 for generating slip torque is attached to the tuning knob 8 side, but when assembling or removing the tuning knob 8, there is a risk that the coil spring 9 may hit a hole in the cabinet and fall off. be.

Conventionally, countermeasures have been taken to prevent this from falling off, such as making the rib 8-3 higher, but the rib 8-3 makes it difficult for the bearing lip 8-1 to bend, which reduces the tightening force of the coil spring 9. becomes ineffective and the slip torque becomes unstable. The tuning knob insertion hole in the cabinet is made as small as possible to prevent the tuning knob from deflecting in the radial direction when rotating.

OBJECTS OF THE INVENTION An object of the present invention is to provide a dial device that can provide stable slip torque.

Structure of the Invention In order to achieve the above object, the dial device of the present invention comprises:
A bearing comprising a tuning shaft configured to drive a variable capacitor drum attached to a variable cap shaft using gears, a tuning knob for manually operating this tuning shaft, and having two or more slits provided in the tuning shaft. A coil spring is placed in the shaft, and the shaft of the tuning knob is fitted onto the inner surface of the tuning shaft, so that it slips and rotates when a torque above a certain level is applied between the tuning shaft and the tuning knob. .

DESCRIPTION OF THE EMBODIMENTS FIG. 2 is a front view showing an embodiment of the present invention, and FIG. 2 is a sectional view at the center of the tuning shaft portion thereof. A printed wiring board 2, a dial 7, and a coating 3 are attached to the cabinet 1. A variable capacitor 4 is attached to the printed wiring board 2, and a variable capacitor drum 6 is fixed to the main shaft 4-1 of the variable capacitor 4 with screws so as to rotate together with the variable capacitor shaft 4-1. The variable converter drum 6 is formed with a bevel gear 6-1 and a spur gear 6-2.

The dial chassis 3 is provided with a bearing part 3-1 on which a tuning shaft 6 is rotatably mounted, and a guide part 3-2, 3-3 for the pointer 7.The tuning shaft 6 is provided with the bearing part 3-1. It has a shaft part that fits into the shaft part and an elastically deformable claw part to prevent it from coming off after insertion. The rack gear part 7-1 of the 0 pointer 7, whose tip end bevel gear part 6-1 meshes with the bevel gear part 6-1 of the variable converter drum 5 in the inserted state, is connected to the spur gear part 5 of the control drum 5. -2
As shown in FIGS. 4 and 5, the tuning shaft 6 has a bearing part 6-2 into which the shaft parts 8-4 and 8-6 of the tuning knob 8 fit. and 6-4 are provided with a foot, and a bearing part 6-
2 has a slit formed therein so that it can be deformed in the radial direction. A coil spring 9 is press-fitted to the outer periphery of the tuning shaft 6 and the tuning knob 8, and when a torque above a certain level is applied between the tuning shaft 6 and the tuning knob 8, the coil spring 9 rotates relative to the tuning shaft 6 and the tuning knob 8. Due to the configuration, when the tuning knob 8 is rotated, the tuning shaft 6 and the variable capacitor drum 6 are connected to the bevel gear 5-1.
．． At the same time, the variable capacitor shaft 4-1 rotates due to the meshing of the variable capacitor drum 5 and the pointer 7 with the spur gear 5-2.6-1.
The pointer 7 slides due to the engagement of 7-1. The rotation of the variable capacitor shaft 4-1 is approximately 1/2 rotation, but when the variable capacitor shaft 4-1 is fully turned to the left or fully clockwise, the variable capacitor shaft 4-1 is rotated between the no. At this point, the tuning shaft 6 stops rotating.And when the tuning knob 8 is further turned, it slips and rotates between the tuning knob 8 and the tuning shaft 6.Here, the shaft part 8 of the tuning knob 8
-4 is provided to prevent deflection in the radial direction when operating the tuning knob 8, and is not particularly necessary if the shaft portion 8-6 is sufficiently long.

A rib 6-3 is provided on the outer periphery of the tuning shaft 6,
This is provided to escape the breakage on the end face of the coil spring 9, and is also effective for further stabilizing the slip torque.

In addition, when the coil spring 9 has a reed near the end face of the tuning shaft 6 and there is a risk of it falling off, a detachment prevention rib 6-5 is provided.
You can also add .

Effects of the Invention As described above, according to the present invention, a material with a small coefficient of friction, such as acetal resin, can be used for the bearing part.
Even if a slit is formed, there is no risk of damaging the shaft at the corner, and even if the tuning knob is plated with resin, it will be relatively uniform and dimensionally stable.
0 which can stabilize slip torque
In addition, since the coil spring is attached to the tuning shaft, there is no risk of it falling off when inserting or removing the tuning knob, which is extremely valuable in terms of quality stability and mass production.Q

[Brief explanation of drawings]

FIG. 1a is a side sectional view of a conventional dial device, FIG. 1 is a longitudinal sectional view thereof, FIGS. Figures 4 and 6
The figure is an enlarged sectional view of the main parts of the device. 4... Variable capacitor, 6... Variable capacitor drum, 6... Tuning shaft, 8... Tuning knob, 9... Coil spring. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure (Oshi) (i&) Figure 2 Figure 3 1 -5

Claims (3)

[Claims] (1) It is equipped with a tuning shaft configured to drive the variable capacitor drum attached to the variable capacitor shaft with gears, and a tuning knob for manually operating the tuning shaft, and the above tuning shirt) K is provided at two or more locations. A dial device characterized in that a coil spring is fitted to the outer periphery of a bearing portion having a slit, and at the same time a shaft portion of a tuning knob is fitted to the inner surface of the bearing portion. (2) The dial device according to claim 1, characterized in that two or more lips are provided on the outer layer of the bearing portion of the tuning shaft. (3) The dial device according to claim 1, characterized in that the outer layer of the bearing portion of the tuning shaft is provided with two or more claws for preventing the coil spring from being pulled out.