JPH0614509Y2 - Tuning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tuning mechanism of a mobile device, and an object of the present invention is to move a pointer indicating a tuning frequency even if a small variable resistor (or variable capacitor) is used. To provide a large amount of tuning mechanism.

A small electronic device having a receiving function is provided with a tuning mechanism that mechanically or electrically determines the receiving frequency.
Most of the mechanically tuned methods are thread-threaded or worm-axis based. These methods will be briefly described. FIG. 1 shows a threading type tuning mechanism, and FIG. 2 shows a worm shaft type tuning mechanism, both of which are mechanisms for rotating a variable resistor 1 which determines a tuning frequency. The threading type comprises a tuning knob 2, a pulley 3 for changing the direction, a wheel 4 attached to the rotary shaft of the variable resistor 1, and a thread 5 connecting these. The thread 5 is always in a tensioned state, and when the tuning knob 2 is rotated, it moves without slipping, and the wheel 4 is rotated to adjust the variable resistor 1 to the tuning frequency. In the worm shaft system, a worm shaft is used instead of the thread-hanging type thread, and the tuning knob 6, the worm shaft 7 and the variable resistor 1 are used.
And a worm wheel 8 attached to the rotation shaft of the. By rotating the tuning knob 6 fixed to one end of the worm shaft 7, the worm shaft is rotated,
The worm wheel 8 is rotated to adjust the variable resistor 1 to a desired synchronizing frequency. According to the above-mentioned method, the tuning knob is rotated to adjust the rotation of the variable resistor. In either method, a means for displaying the tuning frequency is required. In the case of the thread-hanging type, an indicator needle 9 is fixedly displayed on a part of the thread 5, and the user is informed of the tuning frequency by indicating the frequency scale displayed on the case or the like.
Further, in the case of the worm shaft system, the indicator needle 10 that moves by engaging with the worm shaft 7 indicates the tuning frequency. By the way, in either method, the movement amount of the indicator needle moves only by the rotation amount of the variable resistor. That is, in the case of the yarn hooking type, it is a value obtained by multiplying the moving amount of the yarn, that is, the radius of the wheel 4 by the rotation angle of the variable resistor. In the case of the worm shaft system, it is a value obtained by multiplying the radius of the worm wheel 8 by the radius of the variable resistor. Therefore, if the variable resistor used becomes smaller along with the miniaturization of the portable receiving device, the rotation angle is usually narrowed. In addition, the diameter of the wheel that attaches the variable resistor to the rotary shaft has to be small in terms of space, and as a result, the amount of movement of the indicating needle becomes extremely narrow, making it difficult to select the tuning frequency. It was not so good in terms of design.

The present invention overcomes such drawbacks and provides a tuning mechanism capable of increasing the movement amount of a tuning indicator needle while using a small variable resistor (or variable capacitor) having a small rotation angle. The present invention will be described below based on examples.

FIG. 3 shows an embodiment of the present invention, which is particularly applied to the worm shaft type.

FIG. 4 is a partial sectional view of FIG. 3 seen from the direction of arrow A.

A rotary gear 12 is fixed to the rotary shaft of the variable resistor 11 that determines the tuning frequency. The transmission gear 13 meshes with the rotary gear 12, and the worm wheel 14 and the transmission gear 13
Are connected and fixed. Reference numeral 15 is a support plate, which is a rotary gear 12
A bearing for the rotating shaft of the worm wheel 14 is provided which rotates about the central axis of the. Therefore, the worm wheel 14 freely rotates about the variable resistor 11 as the support plate 15 rotates about the rotation gear 12 while ensuring the meshing between the transmission gear 13 and the rotation gear 12. It becomes a structure to do. The worm wheel 14 is pressed against the worm shaft 17 by a leaf spring 16 and the like, and always meshes with the worm shaft without any backlash. An indicator needle 18 is meshed with the other worm shaft, and the worm shaft is moved on the worm shaft by turning a tuning knob 19 fixed to one end of the worm shaft 17. According to the embodiment of the present invention as described above, even if the rotation angle of the variable resistor 11 is small, the pointer 1
The moving amount of 8 can be increased. This will be explained by the operation of the apparatus of the embodiment.

When the tuning knob 19 is turned, the worm shaft 17 rotates, the indicator needle 18 moves by the amount of the rotation, and the worm wheel 14 rotates by exactly the amount of movement. Since the transmission gear 13 is connected and fixed to the worm wheel 14,
Transmission gear 13 with worm wheel by the same rotation angle
Rotates. Since the rotary gear 12 is always meshed with the transmission gear 13, the rotation of the transmission gear 13 causes the rotation gear 12 to rotate. The rotary gear 12 rotates the variable resistor 11 to adjust the tuning frequency. Therefore, at this time, when the rotary gear 12 and the transmission gear 13 are in deceleration engagement, the rotation angle of the rotary gear 12 can be made smaller than the rotation angle of the worm wheel 14. For example, when the reduction ratio is set to 2: 1, when the worm wheel 14 rotates 360 degrees, the rotary gear 12 only needs to rotate 180 degrees, and eventually the variable resistor 11 can also rotate 180 degrees. For the above reasons, even if a variable resistor with a small rotation angle is used, the tuning mechanism of the present invention can increase the rotation angle of the worm wheel by setting the reduction ratio appropriately. It is possible to increase the movement amount of the pointer.

As described above, the present invention provides a variable resistor or a variable capacitor for determining a reception frequency, a first rotating member connected and fixed to a rotary shaft of the variable resistor or the variable capacitor, and the first rotating member. A second rotating member meshed with the moving member and fixedly connected to the worm wheel; a support plate rotatably supporting the first rotating member and the second rotating member; A worm shaft connected and fixed to a local knob, an indicator needle that moves along the worm shaft by the rotation of the second rotating member, and a spring on a plate that presses the worm wheel against the worm shaft. As a result, the following effects can be obtained.

(A) Since the first rotating member and the second rotating member are pivotally supported by the supporting member, it is not necessary to fix these rotating members to the chassis, so that the space in the chassis can be effectively utilized. it can. Further, since the rotating member, the worm wheel and the like are first assembled on the support plate and then assembled on the chassis, they can be fixed to the variable resistor or the variable capacitor, so that the assembling process can be simplified.

(B) By providing a leaf spring in which the worm wheel is pressed against the worm shaft,
The support plate can be prevented from rotating, and the worm shaft and the worm wheel can engage with each other without backlash. Therefore, accurate tuning can be performed.

[Brief description of drawings]

FIG. 1 is an explanatory view of a conventional threading type tuning mechanism, and FIG. 2 is an explanatory view of a conventional worm shaft type tuning mechanism. FIG. 3 is a mechanism explanatory view showing an embodiment of the tuning mechanism of the present invention,
FIG. 4 is a view of FIG. 3 seen from another angle. 1 ... Variable resistor, 2 ... Tuning knob 3 ... Pulley, 4 ... Wheel 5 ... Thread, 6 ... Tuning knob 7 ... Worm, 8 ... Worm wheel 9 ... Indicator needle, 10 ...... Indicator needle 11 ...... Variable resistor, 12 ...... Rotary gear 13 ...... Transmission gear, 14 ...... Worm wheel 15 ...... Support plate, 16 ...... Leaf spring 17 ...... Worm shaft, 18 ...... Indicator needle 19 ...... Channel selection knob

Claims (1)

[Scope of utility model registration request] 1. A variable resistor or a variable capacitor for determining a reception frequency, a first rotating member connected and fixed to a rotating shaft of the variable resistor or the variable capacitor, and the first rotating member. Second rotating member meshed with the worm wheel and fixed to the worm wheel, a support plate rotatably supporting the first rotating member and the second rotating member, and a tuning knob meshed with the worm wheel. A worm shaft connected and fixed to the worm, an indicator needle that moves along the worm shaft by the rotation of the second rotating member, and a leaf spring that presses the worm wheel against the worm shaft. Tuning device characterized by.