JPH0346588Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The invention relates to a frequency display mechanism for a tuner. This invention relates to a frequency display mechanism that includes a scale plate integrally formed.

(Prior art) Tuners such as radio receivers are equipped with a tuning frequency display mechanism, and one of these display mechanisms is a system that rotates a disc-shaped scale plate with the pointer fixed. something has been known for a long time.

Conventionally, in this display mechanism, there was a misalignment between the tuning axis rotated by the tuner user, the axis of the variable capacitor, and the central axis of the scale plate due to design or installation errors. The pulleys were fixed and looped strings were strung around these pulleys, and this string transmitted the rotational force of the tuning shaft to the variable capacitor and scale plate.

(Problem that the invention aims to solve) However, in the above-mentioned tuner using a string, slippage between the pulley and the string tends to cause misalignment between each axis, and the frequency set by the variable capacitor and There was a risk that the display on the scale plate would not match. In addition, transmission of rotational force using pulleys and strings is effective when the tuning shaft and the variable capacitor or scale plate rotated by it are located at a distance, but recently there has been a demand for miniaturization of equipment, so these are It was unsuitable when it was installed close to one location.

Furthermore, in addition to essential components such as the tuning shaft, variable capacitor, and scale plate, parts such as pulleys and strings that simply transmit rotational force are required, so there are many parts and assembly is complicated. It was hot. In particular, the process of hanging a thin thread around a pulley at a constant tension and tying both ends into a loop is not only impossible to assemble automatically, but also a cumbersome process that takes several minutes even for experienced workers. It was hot from work.

The present invention was proposed in order to solve the problems of the conventional technology as described above, and its purpose is to prevent deviation between the set frequency by the variable capacitor and the frequency display on the scale plate, to reduce the number of parts, and to reduce the number of parts. To provide a frequency display mechanism for a tuner that is small and easy to assemble.

[Structure of the invention] (Means for solving the problems) The frequency display mechanism of the invention connects the tuning shaft and the variable capacitor through a universal joint, thereby arranging them in a substantially straight line. The above-mentioned problem is solved by integrally forming the scale plate on the joint member that constitutes the joint member.

(Function) In the present invention having the above configuration,
Even if there is a positional deviation between the tuning shaft and the variable capacitor due to design or installation error, this positional deviation can be absorbed by the universal joint, and the rotation of the tuning shaft can be reliably transmitted to the variable capacitor.

In addition, since the scale plate is integrated with the universal joint that rotates at the same time as the tuning shaft,
There is no rotational error between the tuning shaft, variable capacitor, and scale plate, and the display on the variable capacitor and scale plate will surely match.

Furthermore, since the scale plate is directly installed on the universal joint, there is no need for a dedicated rotational force transmission member, and the number of parts and assembly man-hours can be reduced.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

*Configuration of the embodiment* As shown in FIGS. 1 and 2, the shaft 2a is located on the printed circuit board 1 of the tuner.
The variable capacitor 2 is fixed so as to be perpendicular to the position. On the other hand, the chassis 3 of the tuner, which is arranged parallel to the printed circuit board 1 at a constant distance, has a tuning shaft 5 in a bearing 4 provided perpendicularly to the chassis 3.
is rotatably supported. This tuning shaft 5 and the shaft 2a of the variable capacitor may be coaxial, but due to design or installation errors, their axes may be misaligned within the range where rotational force can be transmitted by the universal joint. It's okay.

A universal joint 6 is provided between the tip of the shaft 2a of the variable capacitor and the end of the tuning shaft 5 on the variable capacitor side, and the rotation of the tuning shaft 5 is transmitted to the variable capacitor 2 by this universal joint 6. It is becoming more and more common. This universal joint 6 is also called an Oldham joint, and is an input joint member 6 that rotates together with the tuning shaft 5.
a, an output joint member 6b that rotates together with the shaft 2a of the variable capacitor, and a transmission joint member 6c disposed between the two. Among these, the input joint member 6a is
It is a disc-shaped member press-fitted into the shaft end of an oval-shaped tuning shaft 5, and a protrusion 7 extending in the diameter direction of the disc is provided on its surface facing the variable condenser. The intermediate transmission joint member 6c is also a disk-shaped member, and its tuning shaft side surface has a groove 8 into which the protrusion 7 on the surface of the input joint member is slidably fitted.
are provided in the diametrical direction of the disc. Further, on the surface of the transmission joint member 6c on the variable condenser side, a groove 9 in a direction orthogonal to the groove 8 is provided in the diametrical direction of the disc.

The output joint member 6b is fitted into the tip of the shaft 2a of the variable capacitor, which has an oval-shaped cross section, so as not to rotate, and is further inserted from the center of the joint member 6b so as not to slip out beyond a certain dimension from the end of the shaft 2a. The inserted screw 10 is screwed to the tip of the shaft 2a. That is, the joint member 6b is attached to the shaft 2a of the variable capacitor so as to be non-rotatable and movable by a certain distance in the axial direction. A coil spring 11 is compressed between the back surface of the joint member 6b and the variable capacitor 2, and the joint member 6b is always urged toward the tuning shaft 5 by the coil spring 11.

This joint member 6b is also a disc-shaped member, and a protrusion 12 extending in the diametrical direction is provided on the surface of the joint member 6b on the side of the tuning shaft.
is provided, and this protrusion 12 is slidably fitted into a groove 9 formed on the variable condenser side surface of the transmission joint member 6c. In addition, the center part of this protrusion 12 connects this joint member 6b to the shaft 2.
This serves as an insertion hole 13 for a screw 10 to be screwed into a.

Now, in this embodiment, the scale plate 20 is integrally provided on the joint member 6b on the variable condenser side of the universal joint 6 as described above. That is, a cylindrical support part 21 extending toward the tuning shaft 5 side is integrally formed around the disc-shaped joint member 6b, and a ring-shaped support part 21 or a fan-shaped part with a part of the ring cut away is formed at the tip of this support part 21. A scale plate 20 is provided. The scale plate 20 may display characters or the like by direct printing or the like, or a sticker or a thin plate with characters or the like printed thereon may be attached to the surface of the scale plate 20.

*Operation of the embodiment* In this embodiment having the above configuration, when the tuning shaft 5 is rotated, the rotational force is transmitted to the input joint member 6a, the transmission joint member 6c, and the output joint member 6b. Since the signal is transmitted to the shaft 2a of the variable capacitor 2, the variable capacitor 2 rotates and a desired tuning frequency can be obtained. At the same time, the scale plate 20 integrally provided on the joint member 6b of the universal joint 6 rotates, and the characters, etc. on the scale plate 20 are read by a pointer provided on the cabinet or case display window (not shown). , the tuning frequency set by the variable capacitor 2 can be read.

*Effects of the embodiment* In this embodiment having the above-described configuration, the tuning shaft 5, the variable capacitor 2, and the scale plate 20 rotate as one, so that the set frequency and the display on the scale plate are different. There will be no gaps between images, and the display will be accurate. In addition, since the scale plate is attached directly to the universal joint that is provided to eliminate misalignment between the tuning shaft and the variable capacitor, there is no need for a rotational force transmission member dedicated to the scale plate, reducing the number of parts and making the entire mechanism smaller. It is also possible to

In addition, even if there is an axial misalignment between the tuning shaft 5 and the shaft 2a of the variable capacitor, the universal joint 6 provided in the middle absorbs this, so even if some installation errors occur during the tuning assembly process. There is no problem. In addition, since the rotation of the tuning shaft 5 is transmitted to the variable capacitor by the universal joint 6,
There is no rotation loss between the two, and synchronization can be performed smoothly.

In this embodiment, since the joint member is pressed against the other joint member using a coil spring, the frictional force between the joint members becomes constant, and the rotational force is transmitted more smoothly.

*Other embodiments* The present invention is not limited to the above-mentioned embodiments; for example, the scale plate may be provided on the input side of the universal joint, that is, on the joint member that rotates together with the tuning shaft. .

Further, instead of writing letters on the surface of the scale plate, a pointer may be written on the scale plate, and letters etc. indicating the frequency may be written on a display window provided on the cabinet or case side of the tuner.

Furthermore, when the universal joint is made from a resin molded product or a metal die-cast product, it is desirable to integrally mold the joint member and the scale plate, but it is not possible to fit the joint member and the scale plate, which are made from separate parts. , they may be integrated by means of adhesion, screwing, welding, or the like.

[Effects of the invention] As described above, according to the invention, the scale plate is integrated with the universal joint between the tuning shaft and the variable capacitor axis. It is possible to provide a frequency display mechanism for a tuner that has no deviation from a set frequency, has accurate display, has a small number of parts, is easy to assemble, and is miniaturized.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an embodiment of a frequency display mechanism of a tuner according to the present invention, and FIG. 2 is a sectional view of the same. 1... Printed circuit board, 2... Variable capacitor, 2a...
...Variable capacitor shaft, 3... Chassis, 4... Bearing,
5... Tuning axis, 6... Universal joint,
6a, 6b, 6c...Joint member, 7...Protrusion, 8...Groove, 9...Groove, 10...Screw, 11...
...Coil spring, 12...Protrusion, 13...Screw insertion hole, 20...Scale plate, 20a...Plate on which scale characters are printed, 21...Support part.

Claims (1)

[Claims for Utility Model Registration] a. A tuning shaft and a variable capacitor arranged substantially in a straight line. b Universal joint that connects the tuning shaft and variable capacitor shaft. c A scale plate integrally formed on the joint member that constitutes the universal joint. A frequency display mechanism for a tuner, characterized in that it has the configuration requirements a to c above.