JPH0136355Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a dial drive device for communication equipment, etc.

Configuration of conventional example and its problems A rope is used in a conventional dial drive device, and a helical spring or wire spring is used as a method of applying a constant tension to the rope.

The conventional structure will be explained below with reference to the drawings.

Figure 1 shows a structure using a conventional helical spring, with 1 being a dial drum and 2 being a dial drum.
3 is a variable capacitor, 4 is a screw, 5 is a dial rope, 6 is a pointer, 7 is a tuning knob, 8 is a roller, 9 is a printed wiring board, and 10 is a chassis. The dial drum 1 is fixed to the variable capacitor 3 with screws 4, and the variable capacitor 3 is attached to the printed wiring board 9.
is soldered to. Also tuning knob 7
is fixed to the chassis 10 via a printed wiring board 9 with a nut, and the roller 8 is fixed to the chassis 10 via a mounting shaft.

The operation of the conventional dial drive device configured as described above will be described below.

First, in order to rotate the shaft of the variable capacitor 3 when selecting a channel, the tuning knob 7 is rotated.

At this time, the shaft of the variable capacitor 3 cannot be rotated unless the rope 5 has a certain tension, so one end of the helical spring 2 is tied to the rope 5, and the other end of the helical spring 2 is connected to the dial drum. It's hooked up to 1. When the tuning knob 7 is rotated, the pointer 6 attached to the rope 5 moves sideways, the dial drum 1 rotates, and the frequency displayed on the cabinet can be read depending on the position of the pointer 6. . However, in the above configuration, the work of tying the rope 5 to the helical spring 2 involves cutting the rope 5 to a certain length, making it into a loop, and then tying it to one end of the helical spring 2. The work required considerable skill and was very time-consuming. Furthermore, since the effective diameter of the helical spring cannot be made small, there is a problem in that the thickness of the dial drum increases.

Next, a second conventional example will be explained with reference to FIG. As a second conventional example, a wire spring is sometimes used as a method of applying tension to a rope. In FIG. 2, 1 is a dial drum, 2 is a wire spring, 3 is a variable capacitor, 4 is a screw, and 5 is a rope. In this case, one end of the wire spring 2 is fixed, a rope 5 is tied to the other end, and the rope 5 is set at the center of the wire spring 2 as a fulcrum.
It gives tension to. However, in this example, since the wire spring was supported at only one point, the support of the wire spring was unstable, and at the same time, compared to a helical spring, it was not possible to obtain a spring force that could provide sufficient tension to the rope. . Furthermore, in order to obtain sufficient spring force, the diameter of the wire spring must be increased, which is disadvantageous in terms of cost.

Purpose of the invention The object of the invention is to provide a compact dial drive device that has a simple structure and can apply sufficient tension to a rope.

Structure of the invention The invention forms two supporting parts facing each other on a dial drum attached to a variable capacitor, and
Lock both ends of the wire spring to two supports,
This dial device has a structure in which a rope is secured to the center of this wire spring.

DESCRIPTION OF EMBODIMENTS FIG. 4 shows the configuration of a dial drum section in a first embodiment of the present invention. In Fig. 4, 11 is a dial drum, 12 is a wire spring with one turn in the center, 13 is a variable capacitor, 14 is a screw, 1
5 is a rope. As shown in FIG. 4, the rope 15 is made into a loop in advance, and this is inserted into the wire spring 12 whose central portion is made into a loop, and then the wire spring 12 is further inserted into the dial drum 11 as shown in FIG. has been completed. And the rope 15
Both ends of the wire spring 12 are hooked onto two support parts 11a and 11b provided on the dial drum 11.

As described above, according to this embodiment, the spring 12 for applying tension to the rope 15 can be provided in an extremely simple shape and at low cost.
Since a wire spring is used, the thickness of the dial drum can be reduced by the effective diameter of the helical spring, and the dial drum can be made smaller. Furthermore, unlike the conventional wire spring that supports one end, the wire spring has two fulcrum points, so the wire spring can be supported stably. Since the structure is such that the tension is applied by the spring parts on both sides, which are divided into two, it is possible to apply sufficient tension to the rope, which is the same as that of a coiled spring even with a wire spring.
Also, in the past, you had to tie a looped rope to a helical spring or wire spring, but
This embodiment has the advantage that the looped rope can be inserted and locked in the loop at the center of the spring, so it is extremely easy to work with and does not require much skill on the part of the operator.

In addition, in the first embodiment, the wire spring 2 was provided with a loop in the center as shown in the figure, but this wire spring has a fifth loop.
Similar effects can be obtained with shapes such as those shown in FIG. 6, FIG. 7, and FIG.

Effects of the invention As described above, according to the invention, both ends of the wire spring are respectively locked to the two opposing support parts of the dial drum, and the rope is locked to the center of the wire spring. Since the structure is such that a constant tension is applied to the rope by the spring parts on both sides, the wire spring maintains a stable locking state by being supported at two points, and the rope is suspended by the spring force of the wire spring parts on both sides. Sufficient tension can be applied to ensure stable dial drive. In addition, since the wire spring is locked with two support parts provided on the dial drum, the dial drum can be made thinner.
As a whole, the dial driving device can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventional dial drive device, FIG. 2 is a plan view of a main part of a dial drum section of a conventional dial drive device, and FIG. 3 is a dial drum section in an embodiment of the dial drive device of the present invention. Fig. 4 is an explanatory diagram of installing the wire spring and rope, Fig. 5, Fig. 6, and Fig. 7 are the plan views of the main parts of the present invention.
FIG. 11...Dial drum, 11a, 11b...
Support part, 12... Spring, 13... Variable capacitor, 15
……rope.

Claims (1)

[Claims for Utility Model Registration] A variable capacitor, a tuning knob, and a roller are arranged on a board at a constant interval from each other, and a dial drum attached to the variable capacitor, the tuning knob, and a pointer are attached to the roller. A dial driving device that rotates the dial drum by suspending a looped rope and rotating the tuning knob, the dial driving device comprising: 1. two support portions facing each other on the dial drum; 2. By locking both ends of a deformable wire spring to two support parts, respectively, and by locking the rope to the center of the wire spring, the spring force of the wire spring supported at two points in the support part is reduced. A dial drive device characterized in that the dial drive device is configured such that a constant tension is always applied to the rope.