JPH0611644Y2 - Dial operation device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a dial operation device for performing a dial operation for tuning, in particular, a tuning variable capacitor is mounted on a circuit board, and a rotary shaft of the variable capacitor is mounted on the rotary shaft of the variable capacitor. The dial drum was attached, and a part of the outer periphery of the dial drum was exposed to the outside through the cabinet opening. The dial drum was rotated from the outside of the cabinet through the cabinet opening to perform the synchronizing operation. The present invention relates to a dial operation device suitable for use as a tuning device.

[Outline of device]

According to the present invention, the dial drum attached to the rotary shaft of the variable condenser is provided with an insertion hole along the circumferential direction, and the supporting boss for supporting the circuit board is inserted into the insertion hole, and the dial drum is attached. This boss prevents lateral pressure from being applied to the rotary shaft of the variable condenser when a pressing force is applied, and the rack having a pointer is crimped to the pinion provided on the dial drum by the boss. is there.

[Conventional technology]

Generally, a radio receiver is provided with a tuning variable condenser, and a tuning operation is performed by rotating the rotary shaft of the variable condenser to change its capacity. Conventionally, the rotation of the dial knob is transmitted to the rotary shaft of the variable condenser by a dial thread. However, such a structure complicates the structure of the dial operation device. Therefore, the dial drum should be directly attached to the rotary shaft of the variable condenser, and a part of the outer peripheral side of this dial drum should be exposed to the outside through the cabinet opening, and this part should be rotated from the outside of the cabinet with fingers. A dial operating device is used which is adapted to perform a tuning operation.

[Problems to be solved by the invention]

According to the dial operating device in which the dial drum is directly attached to the rotary shaft of the variable condenser and the dial drum is rotationally operated from the outside of the cabinet as described above, when a large force is applied to the dial drum,
Lateral pressure may be applied to the rotary shaft of the variable condenser. When a large lateral pressure is applied, stress may be generated or deformed on the rotary shaft of the variable capacitor. Alternatively, there is a possibility that a large stress may be generated in the lead of the variable capacitor which is soldered to the printed wiring portion while being inserted into the small hole of the printed wiring board, or the solder may be cracked to cause a disconnection.

The present invention has been made in view of such a problem, and a dial operating device in which a dial drum, which is designed to be directly rotated from the outside of a cabinet, is directly attached to a variable condenser, has a large external force. It is an object of the present invention to provide a dial operation device that prevents lateral pressure from being applied to the rotary shaft of a variable condenser even if force is applied.

[Means for solving problems]

According to the present invention, a dial drum attached to a rotary shaft of a variable condenser is provided with a through hole provided in a substantially arcuate shape on a concentric circle centered on the rotary shaft, and a laterally long opening for operating the cabinet of the dial drum. A boss that is inserted into the through hole of the dial drum between the facing portion and the rotary shaft, and that prevents the rotary shaft from being applied with a pressing force for operating the dial drum. The present invention relates to a dial operation device including:

[Action]

When a portion of the cabinet facing the outside of the dial drum is rotated through the horizontally elongated opening for operating the cabinet, the rotation of the dial drum is transmitted to the variable condenser through the rotary shaft of the variable condenser, thereby changing the capacity of the variable condenser and performing the synchronizing operation. Since the pressing force applied to the dial drum at the time of such an operation is received by the boss, the above pressing force is not transmitted to the rotary shaft of the variable condenser.

〔Example〕

FIG. 2 shows a cassette tape recorder with a radio equipped with a dial operating device according to an embodiment of the present invention. Speaker cabinets 11 are provided on both sides of the front side of the cabinet 10, respectively. A speaker is arranged inside. And speaker grills 1 on both sides
A cassette mounting portion 12 is provided in a portion between the two, and a tape cassette is mounted on the cassette mounting portion 12 for recording or reproducing. A dial display portion 13 is provided on the upper side of the cassette mounting portion 12, and a dial pointer 14 runs laterally on a dial scale plate of the dial display portion 13. Further, a horizontally long opening 1 is provided on the upper surface side of the cabinet 10.
5 is provided, and the outer peripheral portion of the dial drum 16 faces this opening 15.
When 6 is rotated, the pointer 14 moves laterally to indicate the selected frequency.

Next, the structure of the dial operating device in the cabinet 10 will be described. As shown in FIG. 1 and FIG.
A printed wiring board 19 is arranged in the cabinet 10, and a circuit component 20 is mounted on the board 19 to form a circuit of a radio receiver and a circuit of a tape recorder. Further, a variable capacitor 21 is mounted on the printed board 19. The rotary shaft 22 of the variable capacitor 21 is a circular hole 23 of the printed wiring board 19.
Through the dial drum 1
The tubular boss portion 24 of No. 6 is fitted. The tubular boss portion 24 and the rotary shaft 22 are connected to each other by a screw 25, so that the dial drum 16 is attached to the rotary shaft 22 of the variable condenser 21.

A ring-shaped projection 26 is integrally provided on the front side of the dial drum 16, and a pinion 27 is formed on the outer peripheral surface of the projection 26. A flexible rack 28 made of synthetic resin meshes with the pinion 27. A locking portion 29 is formed on the base end side portion of the rack 28, and the locking portion 29 is received by the locked portion 30 formed on the ring-shaped protrusion 26, whereby the rack 28 is provided. The end of 28 is fixed to the dial drum 16. The dial pointer 14 is integrally connected to the front end of the rack 28. Further, the dial drum 16 is formed with an insertion hole 31 on the outer peripheral side thereof over a range of about 180 degrees in the circumferential direction. The supporting boss 32 protruding from the inner surface on the front side of the cabinet 10
While being inserted through the insertion hole 31, the printed wiring board 19 is mounted by a screw 33 at the tip thereof.

In the above configuration, the dial drum 1 facing the horizontally elongated opening 15 formed on the upper surface of the cabinet 10.
When the outer peripheral portion of 6 is rotationally operated with a finger, the rotation is directly transmitted to the rotary shaft 22 of the variable condenser 21, which changes the capacity of the variable condenser 21. Therefore, it becomes possible to tune to a desired frequency. In conjunction with the tuning operation accompanying the rotation of the dial drum 16, the drum 1
The pinion 27 provided in 6 is driven to rotate, and the pinion 27 drives the rack 28, which moves the rack 28 to the left or right. Then, the pointer 14 integrally provided at the tip of the rack 28 moves on the scale plate of the dial display unit 13 to indicate the tuned frequency.

Dial drum 1 for performing the dial operation in this manner
A supporting boss 32 for supporting the printed wiring board 19 is engaged with the insertion hole 31 of 6, and the boss 32 is in sliding contact with the upper edge portion of the insertion hole 31, as shown in FIG. There is. Therefore, even if a large pressing force is applied to the dial drum 16, this supporting force is received by the supporting boss 32, and no force is applied to the rotary shaft 22 of the variable condenser 21 by the above pressing force. Therefore, the rotating shaft 22 is not deformed or stress is not applied to the lead portion of the variable capacitor 21, and the solder for connecting the lead of the variable capacitor 21 is not cracked to cause connection failure. . Therefore, by receiving the pressing force applied to the dial drum 16 by the supporting boss 32, it is possible to provide a highly reliable dial operating device.

Further, such a dial operating device has a support boss 32 that is inserted through the insertion hole 31 of the dial drum 16.
The rack 28 can be crimped to the pinion 27. Therefore, the teeth of the rack 28 will not fly to the pinion 27, and the correct dial display operation can be performed. Moreover, since the boss 32 that presses the rack 28 is composed of the supporting boss 32 that mounts the printed wiring board 19, no new member is required, and the structure becomes complicated and the cost increases. Nor.

[Advantage of the Invention] As described above, according to the present invention, the insertion hole provided in a substantially arc shape on a concentric circle centered on the rotary shaft of the dial drum attached to the rotary shaft of the variable condenser, and the operation of the dial drum cabinet. It is inserted in the through hole of the dial drum between the part that faces the outside and the rotary shaft by the horizontal opening for use, and when the pressure for operating the dial drum is applied, it is prevented that this pressure is applied to the rotary shaft. And a boss for each.

Therefore, according to such a configuration, even if a large force is unexpectedly applied to the dial drum when the dial drum is rotated through the horizontally long opening for operating the cabinet, the pressing force due to such a large force is applied to the variable condenser. It can be received by the boss that is inserted through the insertion hole, and the above pressing force is prevented from being transmitted to the rotary shaft of the variable condenser.
Therefore, even if an unexpectedly large force is applied to the dial drum,
The rotary shaft of the variable condenser is not deformed and the lead portion of the variable condenser is not broken, so that a highly reliable dial operation device can be provided.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a dial operating device according to an embodiment of the present invention, FIG. 2 is an external perspective view of an entire cassette tape recorder with a radio equipped with this dial operating device, and FIG. 3 is a dial operating device. FIG. In the reference numerals used in the drawings, 10 ... Cabinet 14 ... Dial pointer 15 ... Horizontal opening 16 ... Dial drum 19 ... Printed wiring board 21 ... Varicon 22 ... Rotating shaft 26 ... Ring-shaped protrusion 27 ...... Pinion 28 …… Flexible rack 31 …… Insertion hole 32 …… Supporting boss.

Claims (1)

[Scope of utility model registration request] 1. A dial drum attached to a rotary shaft of a variable condenser, which has a through hole provided in a substantially arcuate shape on a concentric circle centered on the rotary shaft, and a horizontally elongated opening for operating a cabinet of the dial drum. A boss that is inserted into the through hole of the dial drum between the portion facing the rotator and the rotary shaft, and that prevents the rotary shaft from being applied with a pressing force for operating the dial drum. And a dial operation device that includes, respectively.