JPH0818401A - Gear rotation device - Google Patents

Abstract

PURPOSE:To prevent the damage on a variable capacitor by integrally providing a stopper to be locked to a locking part and a gear. CONSTITUTION:The locking parts 21A and 21B integrally formed with a tuning gear 14 are attached to the rotary shaft 13 of the variable capacitor 12. At the time of reception of a lowest frequency, a tuning pointer 20 indicates the display 19A of the lowest frequency by the operation of a tuning knob 15 and the rotary shaft 13 of the variable capacitor 12 is rotated upto a rotation limit position on a low frequency side. At this time, the contact surface 22A of one locking part 21A is brought into contact with a reception part 23 present on the lower side of the tuning knob 15. Thus, even when rotational force is applied so as to rotate the tuning knob 15 more to the low frequency side, the rotational force is only applied to the reception part 23 through a pinion 16, the tuning gear 14 and the locking part 21A and is not transmitted to the rotary shaft 13. Thus, the damage on the rotary shaft 13 and related parts is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear rotation device suitable for application to a radio tuning device or the like.

[0002]

2. Description of the Related Art For example, in a radio tuning apparatus 1 as shown in FIG. 5, a variable condenser (variable capacitor) 12 is attached to a substrate 11, and a tuning gear 14 is fixed to a rotary shaft 13 thereof. On the other hand, a tuning knob 15 is rotatably attached to the substrate 11, and a pinion 16 that meshes with the tuning gear 14 is provided at an intermediate portion of the tuning knob 15. The tuning knob 15 is exposed to the outside from the cabinet 17.

Further, as shown in FIG. 6, a rack 18 is engaged with the pinion 16 of the tuning knob 15, and a tuning pointer 20 for indicating the reception frequency of the variable condenser 12 displayed on the display unit 19 is provided on one side of the rack 18. ing. Now, when you turn the tuning knob 15, the pinion 1
The rotary shaft 13 of the variable condenser 12 is rotated via 6 and the tuning gear 14. As a result, the capacitance of the variable capacitor 12 changes and the reception frequency changes. That is, it becomes possible to select an arbitrary program.

[0004]

By the way, in the conventional tuning device 1, the rotary shaft 13 of the variable condenser 12 is provided.
Rotates only a predetermined angle, and when the rotary shaft 13 stops, the tuning knob 15 also stops. That is, the variable condenser 12 serves as a stopper for the tuning knob 15.

Therefore, if the force for forcibly turning the tuning knob 15 acts when the rotation of the tuning knob 15 is stopped, the tuning gear 14 causes the variable condenser 12 to rotate.
A large load is applied to the rotary shaft 13 of the above, and in some cases, the rotary shaft 13 of the variable condenser 12, parts attached to the rotary shaft 13, and the like may be damaged.

Therefore, the present invention solves the above-mentioned problems and proposes a gear rotation device capable of reliably preventing damage to the variable condenser 12 and the like.

[0007]

In order to solve the above problems, in the present invention, a rotary shaft having a rotation angle of less than one rotation, a gear integrally attached to the rotary shaft, and a gear meshed with the gear. A pinion gear rotation device, in which a locking portion provided concentrically with the axis of the pinion and a stopper for locking the locking portion at the rotation limit position of the rotary shaft are integrally provided with the gear. It is characterized by that.

[0008]

As shown in FIG. 3, the rotary shaft 13 of the variable capacitor (variable capacitor) 12 is provided with locking portions 21A and 21B integrally formed with the tuning gear 14. When the lowest frequency is received, the tuning pointer 20 is operated to point to the lowest frequency display 19A by the operation of the tuning knob 15, and the rotary shaft 13 of the variable capacitor 12 is rotated to the rotation limit position on the low frequency side. At this time, the contact surface 22A of the one locking portion 21A contacts the receiving portion 23 (FIG. 2) below the tuning knob 15. As a result, even if a rotational force is applied in an attempt to turn the tuning knob 15 toward the lower frequency side, the rotational force is transmitted via the pinion 16, the tuning gear 14 and the locking portion 21A.
It will not be transmitted to the rotary shaft 13 even if it takes 3 times. Therefore, it is possible to prevent damage to the rotary shaft 13 and the portion related thereto, that is, the variable condenser 12.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the gear rotating device according to the present invention will be described in detail with reference to the drawings. The same parts as those described above are designated by the same reference numerals and detailed description thereof is omitted.

FIG. 1 shows a configuration of a tuning device 1 to which a gear rotating device according to the present invention is applied, and is a plan view in which a cabinet 17 is partially omitted. In this tuning device 1, a variable condenser (variable capacitor) 12 is mounted on a substrate 11, and a tuning gear 14 is fixed to a rotary shaft 13 thereof. A tuning knob 15 is arranged on the side of the variable capacitor 12 as shown in FIG. 2, and is rotatably attached to the substrate 11.

A pinion 16 is provided below the tuning knob 15 and meshes with the tuning gear 14. A rack 18 is meshed with the pinion 16. A tuning pointer 20 is attached to the rack 18 at an appropriate position, and this is displayed on a display unit 19 provided in the cabinet 17, for example, a display 19A indicating a reception frequency.
Is designed to point to. Now, tuning knob 15
When is turned, the rotary shaft 13 of the variable condenser 12 is rotated via the pinion 16 and the tuning gear 14, and an arbitrary frequency can be selected and received. At this time, the rack 18 moves and the tuning pointer 20 comes to point to the display 19A corresponding to the reception frequency.

As shown in FIG. 1, the tuning device 1 is provided with triangular locking portions 21A and 21B at two lower positions of the tuning gear 14. Locking part 2
1A and 21B protrude by an appropriate length, and an arcuate contact surface 22 is provided on one surface thereof. Also, FIG.
As shown in FIG. 3, a columnar receiving portion 23 having substantially the same curvature as the arc of the contact surface 22 of the locking portion 21 is provided below the pinion 16 of the tuning knob 15. Then, as shown in FIGS. 3 and 4, the contact surfaces 22 of the locking portions 21A and 21B come into contact with the shaft 22 of the tuning knob 15 at the rotation limit position of the rotary shaft 13 of the variable condenser 12. .

That is, as shown in FIG. 3, when the rotary shaft 13 of the variable capacitor 12 is rotated to the limit rotational position corresponding to the minimum reception frequency by operating the tuning knob 15,
The tuning pointer 20 indicates the display 19A showing the lowest reception frequency, 530 kHz in the case of AM. At this time, one locking portion 2 below the tuning gear 14
The contact surface 22A of 1A abuts on the receiving portion 23 below the tuning knob 15. Even if the tuning knob 15 is rotated from this state to the lower frequency side, the locking portion 21A is locked by the receiving portion 23, so that the rotational force applied to the tuning knob 15 is applied to the pinion 16,
Only the power is transmitted to the receiving portion 23 via the tuning gear 14 and the locking portion 21A, and is not transmitted to the rotary shaft 13. Therefore, since no load is applied to the rotary shaft 13, it is possible to prevent the rotary shaft 13 and the parts related thereto from being damaged.

Similarly, as shown in FIG. 4, when the rotary shaft 13 is rotated to the limit rotational position corresponding to the high frequency side, the tuning pointer 20 indicates the display 19A of the highest reception frequency, 1600 kHz in the case of AM. At this time, the contact surface 22B of the other locking portion 21B contacts the receiving portion 23, so that the operating force of the tuning knob 15 cannot be transmitted to the rotary shaft 13 any further. Therefore, since the load is not applied to the rotary shaft 13, it is possible to prevent the rotary shaft 13 and its related parts from being damaged.

[0015]

As described above, the present invention provides a gear rotating device including a rotating shaft having a rotating angle of less than one rotation, a gear integrally attached to the rotating shaft, and a pinion meshed with the gear. The locking portion provided concentrically with the pinion shaft center and the stopper, which is locked to the locking portion at the rotation limit position of the rotary shaft, are integrally provided with the gear. Is.

Therefore, according to the present invention, when the pinion is rotated to the rotation limit position, the stopper attached to the gear attached to the rotary shaft is locked to the locking portion, and the gear is operated even if the pinion is further operated. Also, since the stopper receives the operation force and is not transmitted to the rotary shaft, there is an effect that it is possible to surely prevent the rotary shaft and a portion related thereto from being damaged by being overloaded.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of a tuning device 1 to which a gear rotation device according to the present invention is applied.

FIG. 2 is a view taken in the direction of arrows BB in FIG.

FIG. 3 is a sectional view taken along line CC of FIG. 2 showing a stopped state at the lowest frequency.

FIG. 4 is a cross-sectional view taken along line CC of FIG. 2 showing a stopped state at the highest frequency.

FIG. 5 is a cross-sectional view showing a tuning device 1 of a conventional example.

6 is a view taken along the line AA of FIG.

[Explanation of symbols]

 1 Tuning Device 12 Varicon 14 Tuning Gear 16 Pinion 18 Rack 19 Display 21A, 21B Locking 22A, 22B Abutment Surface 23 Receiving

Claims (2)

[Claims] 1. A gear rotation device comprising a rotation shaft having a rotation angle of less than one rotation, a gear integrally attached to the rotation shaft, and a pinion meshed with the gear, the shaft of the pinion. A gear rotating device comprising: a locking portion provided concentrically with a core; and a stopper, which locks the locking portion at a rotation limit position of the rotary shaft, integrally with the gear. 2. The gear rotating device according to claim 1, wherein the stopper has a concave shape that can be fitted with the locking portion.