JPH0550890B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gear-driven dialing device for a radio receiver or the like.

Conventional configurations and their problems In recent years, gear-driven dial devices have come into use due to improved work costs, stable quality, and improved accuracy. In this gear-driven dial device, the structure of the tuning shaft must be complicated in order to prevent damage due to the rotational force of the variable capacitor shaft. FIG. 1 shows a conventional dial device.

In FIG. 1, the variable capacitor drive gear 2 provided on the tuning shaft 21 and the variable capacitor drum gear 8 on the outer periphery of the variable capacitor drum 7 attached to the variable capacitor shaft 11 are in mesh with each other. A slip plate 1 which has a flat plate part 1 to be attached and also holds a tuning shaft 21 and a tuning knob 4 by friction with a constant force.
7 is axially locked to the flat plate portion 1 provided on the tuning shaft 21 by a plurality of claws 1a. However, with this structure, the tuning knob 4
When rotated to the end of the dial, slip plate 1
Since the stopper of the variable capacitor shaft is protected from being destroyed through the cap 7, the structure for protecting the variable capacitor becomes complicated, resulting in a lot of waste in terms of cost and work.

Purpose of the invention The present invention solves the above-mentioned conventional problems.
It is an object of the present invention to provide a dial device which has a simple structure and can completely protect a rotation stopper of a variable capacitor.

Composition of the Invention The dial device of the present invention provides band-shaped connecting pieces having a width in the rotational direction radially from the center toward the variable converter drum gear on the outer periphery, and a curved part in the axial direction at the center of these connecting pieces. A variable capacitor drum provided with a variable capacitor drum is attached to a variable capacitor shaft, and a tuning shaft integrally formed with a variable capacitor drive gear meshing with a variable capacitor drum gear provided on the outer periphery of the variable capacitor drum and a tuning knob is rotatably supported in a cabinet, The variable capacitor drum gear and the variable capacitor drive gear are arranged so that the distance between their axes is smaller than the sum of the pitch radius of the variable capacitor drum gear and the variable capacitor drive gear, and a pointer is slidably attached to the cabinet. A wide part wider than the width of the band-shaped rack is formed at one end or both ends of a band-shaped rack that meshes with the gear, and the wide part of the rack is configured to engage with a rib provided on the cabinet at the beginning and end of the variable capacitor. This is what I did.

DESCRIPTION OF THE EMBODIMENTS FIG. 2 is a sectional view of a dial device showing an embodiment of the present invention. In the figure, reference numeral 4 denotes a dial drive knob, which has a gear 2 for driving a variable capacitor and a gear 2 for driving a rack, and also has a tuning shaft 18. The tuning shaft 18 is connected to the cabinet 16.
The variable capacitor drum gear 8 and the variable capacitor drive gear 2 are rotatably supported by bearings 15 and 17 implanted in the shaft so that the distance between their axes is smaller than the sum of the pitch radiuses. The cabinet 16 also has a rack 1 integrally formed with the dial frequency display pointer 13.
4 are formed with guide ribs 20a and 20b. Reference numeral 7 designates a variable capacitor drum, which has a variable capacitor drum gear 8 that meshes with the variable capacitor drive gear 2 formed on its outer periphery, and has band-shaped ribs 12 radially curved in the axial direction from the variable capacitor shaft 11 toward the outer circumference. , is fixed to the variable capacitor shaft 11 of the variable capacitor 10 with screws.

Next, the relationship among the pointer 13, rack 14, and cabinet 16 will be explained based on FIG. In the figure, the pointer 13 is positioned at the end of the dial display (the end of the higher frequency side). When the tuning knob 4 is rotated in eight directions, the rotation stopper of the variable capacitor 10 functions and the pointer body 1
3a stops leaving only a distance H from the pointer stopper rib 20a provided on the cabinet 16, but if the knob 4 is rotated any further, the variable capacitor drum 7
is bent in the direction of rotation, and the distance between the pointer body 13a and the stopper rib 20a becomes H=O, and the variable capacitor 1
0 rotation stopper is protected. The setting of H at this time is preferably set to 1 to 3 mm at maximum rotation of the variable capacitor shaft. This is to prevent the variable capacitor drum gear 8 from coming off from the variable capacitor drive gear 2 and causing the pointer to shift. It is also the same even if the tuning knob 4 is rotated in the opposite direction (two directions).
The wide portion 14b at one end of the band-shaped rack 14 is engaged with a stopper 16b installed in the cabinet 16, and at this time as well, the relationship H=1 to 3 mm holds true.

Effects of the Invention As detailed above, according to the present invention, the variable capacitor drive gear and the tuning knob, which are integrally formed on the tuning shaft, drive the pointer rack and drive the variable capacitor drum gear, so that the variable capacitor drum gear is driven at the end or the starting end of the dial. By arranging the wide part of the pointer or the rack to be engaged with the stopper rib installed in the cabinet when the dial is turned, it has the advantage of protecting the rotation stopper of the variable condenser shaft with a simple dial structure.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional dial device, FIG. 2 is a front sectional view showing an embodiment of the dial device of the present invention, and FIG. 3 is a plan sectional view of the same device. 7... Variable capacitor drum, 10... Variable capacitor, 1
1... Variable capacitor shaft, 13... Pointer, 14... Rack, 21... Tuning axis, 20a, 14b...
...stopperrib.

Claims (1)

[Claims] 1. A variable capacitor drum with band-shaped connecting pieces having a width in the rotational direction radially extending from the central part toward the variable capacitor drum gear on the outer periphery, and a curved part in the axial direction in the central part of these connecting pieces is connected to the shaft of the variable capacitor. A tuning shaft integrally formed with a variable capacitor drive gear and a tuning knob that meshes with the variable capacitor drum gear is rotatably supported on the cabinet, and the distance between the shafts of the variable capacitor drum gear and the variable capacitor drive gear is set to the variable capacitor. A band-shaped rack meshing with the variable capacitor drive gear is provided with a pointer which is smaller than the sum of the pitch radius of the drum gear and the variable capacitor drive gear and is slidably attached to the cabinet. A dial device characterized in that a wide part is formed that is wider than the strip width of the rack, and the wide part of the rack is configured to engage with a rib provided on a cabinet at the beginning and end of the variable capacitor.