JPH0339939Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dial device that is most suitable for application to, for example, a radio receiver.

[Conventional technology]

2. Description of the Related Art Conventionally, there are dial devices for multi-band radio receivers as shown in FIGS. 1 and 2.
For example, the first variable capacitor (tuning element) 1 for SW
and a second variable capacitor (tuning element) for FM/MW
2, and pulleys 5 and 6 are attached to these rotating shafts 3 and 4, respectively. A driving thread 9 is wound between a dial shaft 8 to which a dial knob 7 is attached and both pulleys 5 and 6, and a pointer 11 for a dial scale plate 10 is attached to this driving thread 9. . In addition, 12 is a base such as a printed circuit board, 1
3 is a guide pulley. The dial device configured in this manner switches the circuits of both variable capacitors 1 and 2 using a band changeover switch, and operates both variable capacitors while moving the pointer 11 with one driving thread 9 by rotating one dial knob 7. 1 and 2 are used to rotate them at the same time.

[The problem that the idea aims to solve]

However, in such a dial device, the winding length of the driving thread 9 is 5 and 6 times the length of two pulleys.
The total yarn length of the driving yarn 9 becomes very long. As a result, the vibration of the dial knob 7 against both the variable capacitors 1 and 2 due to the expansion and contraction of the drive string 9 becomes large, which makes it difficult to perform synchronized operation. In addition, in a thread-driven dial device, in order to prevent slippage when the pointer 11 is moved by the drive string 9, the drive torque while moving the pointer 11 and the protection of the variable capacitor after it has stopped rotating are used. It is desirable to increase the difference from the slip torque, but in the above structure, the total yarn length of the driving yarn 9 is very long.
Due to the low transmission efficiency seen from the dial knob 7 side and the large load, it is difficult to maintain a large difference between the drive torque and the slip torque, and slips are likely to occur when the pointer 11 moves, making synchronized operation difficult. There is.

Therefore, the present invention aims to provide a dial device that does not cause slips or back crashes.

[Means to solve the problem]

In order to achieve the above object, the dial device of the present invention is configured such that a plurality of tuning elements are rotated simultaneously by rotation of a dial knob. A rotating body having a thread threading groove and a first gear is attached, and a driving thread is provided wound around the dial knob and the thread threading groove of the rotating body.
A second gear is provided that is attached to the rotating shaft of the tuning element and meshes with the first gear, and one of the first and second gears is brought into elastic contact with the other, so that the gears are connected to each other. This is to prevent crashes.

[Effect]

The dial device configured as described above can make the total thread length of the driving thread very short, and the bump against the plurality of tuning elements of the dial knob can be made very small, and the pointer can also be moved. It is possible to increase the difference between the driving torque at the time of rotation and the slip torque after either one of the variable capacitors has stopped rotating. At the same time, the first gear of the rotating body rotationally driven by the driving thread, and the first
Since the second gear rotationally driven by the gear is elastically abutted against each other, no backlash occurs between the first and second gears.

〔Example〕

An embodiment in which the present invention is applied to a multi-band radio receiver will be described below with reference to FIGS. 3 and 4.

First, 21 is a first tuning element, for example, a first variable capacitor for SW, and 22 is a second tuning element, for example, a second variable capacitor for FM/MW. A gear pulley 25 and a double gear 26, which are rotary bodies, are mounted on respective rotating shafts 23, 24) of these variable condensers 21, 22 with setscrews 27, 28, respectively.
It is installed through.

That is, the gear pulley 25 is made of, for example, synthetic resin, and a pair of upper and lower gears 30a, 30b, which are first gears, are integrally molded on the outer periphery of the upper and lower flanges 29a, 29b of the thread hooking groove 29. has been done. The double gear 26, which is the second gear, is made up of two upper and lower gears 3 made of synthetic resin, for example.
It is composed of 1a and 31b. One gear 31a is fitted with a boss 32 integrally molded at the center thereof, and is fitted onto the outer periphery of the upper end of a boss 33 integrally molded at the center of the other gear 31b. One gear 31a has locking claws 34 integrally molded at, for example, three locations on the top surface.
These two gears 31a and 31b are connected to each other so as to be relatively rotatable at a predetermined interval in the axial direction. The other gear 31b is engaged with the rotating shaft 24 at the lower end side of the boss portion 33 at a fitting portion 36 having an oval cross-section, for example, so as to be non-rotatable, and is screwed with a set screw 28. . Notches 3 provided in both gears 31a and 31b
A compression spring 39 is interposed between portions 7 and 38.
The compression repulsive force of the compression spring 39 elastically urges these gears 31a and 31b to rotate in mutually opposite directions, and in this state, both gears 31a and 31b act as the upper and lower gears 30a of the gear pulley 25. , 30b to prevent backlash between the gear pulley 25 and the double gear 26.

On the other hand, one driving thread 43 is wound between the dial shaft 42 to which the dial knob 41 is attached and the thread hooking groove 29 of the gear pulley 25. 45 is installed. Of both ends 43a and 43b of the driving thread 43, one end 43a is tied and fixed to a locking part 46 integrally molded on the gear pulley 25, and the other end 43b is tied to a locking part 46 integrally molded on the gear pulley 25. It is locked to the stop part 47 via a tension spring 48, and the tension spring 4
It is stressed by 8. Note that 49 is a base such as a printed circuit board, and 50 is a guide pulley. The dial shaft 42 is actually supported by the chassis or cabinet, and the dial scale plate 44, guide pulley 50, etc. are also attached to the chassis or cabinet, but the path of the driving thread 43 is schematically shown here.

According to the dial device configured as above,
As in the conventional case, with the circuits of both variable capacitors 21 and 22 switched by the band changeover switch, the gear pulley 2 is moved while the pointer 45 is moved by the driving thread 43 by rotating one dial knob 41.
One of the variable capacitors 21 is rotationally driven through the capacitor 5.
At the same time, the other variable capacitor 22 is rotationally driven by both gears 30a and 30b of the gear pulley 25 via the double gear 26.

However, at this time, the driving thread 43 is only wound around a short path between the dial knob 41 and the gear-doubling pulley 25 provided on one variable capacitor 21, and the other variable capacitor 22 is wound around the double gear 2.
6, the drive yarn 4
The total yarn length of No. 3 can be made very short. Therefore, the backlash of the dial knob 41 against both the variable capacitors 21 and 22 due to the expansion and contraction of the driving thread 9 is extremely small. In addition, since the transmission efficiency as seen from the dial knob 41 side is high and the load is small, the pointer 4
It is easy to make a large difference between the driving torque when the variable capacitors 5 are moving and the slip torque for protecting either variable capacitor 21 or 22 after it has stopped rotating.

Further, the gear pulley 25 has a pair of upper and lower flanges 29a, 29b of the thread hooking groove 29 formed into a pair of upper and lower gears 30a, 30b, and these two gears 30
A pair of upper and lower gears 3 of the double gear 26 are attached to a and 30b.
Since it is configured so that 1a and 31b are meshed,
The thread hooking groove 29 could be effectively arranged within the vertical width (thickness) A of the double gear 26. Therefore, the vertical width (thickness) B of the gear pulley 25 can be made very small, and the amount of protrusion C of the gear pulley 25 relative to the base body 49 can be significantly reduced, making the entire radio receiver thinner. very helpful.

Although one embodiment of the present invention has been described above, the present invention can also be applied to various dial devices other than radio receivers.

[Effect of idea]

Since the present invention is configured as described above,
Since no slip occurs when the pointer moves, and no bumps between gears occur at all, the synchronization operation can be performed very easily and accurately.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing a conventional example, and FIG. 2 is a sectional view taken along the line shown in FIG. 1. FIG. 3 is a schematic plan view showing an embodiment in which the present invention is applied to a radio receiver, and FIG. 4 is a sectional view taken along the line shown in FIG. 3. In addition, in the symbols used in the drawings, 21...1st
Variable capacitor (first tuning element), 22... Second variable capacitor (second tuning element), 23, 24... Rotating shaft, 25... Gear-cum-pulley (rotating body), 26
...Double gear, 29... Thread hook groove, 30a, 30
b...Gear (first gear), 31a, 31b...
Gear (second gear), 41...dial knob,
42...Dial shaft, 43...Drive thread, 45...
It is a guideline.

Claims (1)

[Scope of utility model registration request] In a dial device configured to rotate a plurality of tuning elements simultaneously by rotation of a dial knob, a rotating body having a thread hook groove and a first gear is attached to the rotating shaft of the first tuning element,
Further, a driving string is provided that is wound around the dial knob and the thread hooking groove of the rotating body, and a second gear is provided that is attached to the rotating shaft of the second tuning element and meshes with the first gear. A dial device characterized in that one of the first and second gears is brought into elastic contact with the other to prevent backlash between these gears.