JPS6339473Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a backlash prevention mechanism for a push-button tuner, and in particular, the present invention relates to a backlash prevention mechanism for a push-button tuner, and in particular, the mechanism is provided between a tuning shaft of a push-button tuner and a core slide driven by the tuning shaft. The purpose is to prevent backlash of the gear for transmitting rotational force.

A push-button tuner is a device that tunes a predetermined frequency by rotating a tuning shaft and moving a core slide that is linked to it, and moving the core fixed to the core slide in and out of the tuning coil. be. However, in such a push-button tuner,
Since the tuning shaft and the core slide cannot be directly connected, various rotational force transmission mechanisms are provided between them to transmit the rotation of the tuning shaft to the core slide. As such a rotational force transmission mechanism, one that accurately transmits the rotation of the tuning knob to the core slide is preferable, and various gears are commonly used for this purpose. For example, what is shown in FIG. 1 is an example thereof. That is, 1 is a tuning shaft, and 2 is a drive gear provided at the tip of this tuning shaft. An idler gear 3 meshes with the drive gear 2, and a driven gear 4 meshes with the idler gear 3. A worm shaft 5 is fixed to the driven gear 4, and a worm 6 provided on the worm shaft 5 meshes with a worm wheel 7 rotatably provided on a frame 8 of the tuner. A clutch gear is disposed on the lower side of the worm wheel 7 so as to be able to come in and out of the worm wheel 7.
A rack 10 provided on the core slide 9 meshes with this clutch gear. Note that 11 is a core attached to the vertical portion of the core slide 9, and 12 is a case of a coil into which this core enters.

In such a push button tuner, when the tuning shaft 1 is rotated, the drive gear 2 connected to it rotates, and the rotational force is applied to the idler gear 3 and the driven gear 4.
It is transmitted to the wormshaft 5 via. The rotation of the worm shaft 5 is caused by a worm wheel 7 on the clutch mechanism side through a worm 6 provided on the worm shaft 5.
It is transmitted to When the worm wheel 7 and the clutch gear are in contact with each other, the rotation of the worm wheel 7 causes the clutch gear to rotate, and the rack 10 meshed with the clutch gear moves back and forth to move the core slide, and the core is moved inside the wheel. It is something that goes in and out of.

By the way, in such a rotational force transmission mechanism of a synchronized shaft, the drive gear 2 and idler gear 3 on the synchronized shaft side, or the idler gear 3 and the driven gear 4 on the wormshaft side are connected to shafts at both ends of a narrow mounting plate 20. Holes 21 and 22 were bored into which the support shafts of the respective gears were inserted. However, with this type of gear mounting means, if there is an error in the pitch of each gear, or if there is an error in the spacing of the shaft holes drilled in the mounting plate, the gear supported by this There is a rattling between the two, and as a result,
There was a drawback that bumps occurred when the rotational force was transmitted between each gear. The existence of such a bump makes the movement position of the core by the tuning shaft unstable, which may cause a frequency deviation during the tuning operation. In addition, if we try to improve the pitch accuracy of each gear or the spacing accuracy of the shaft holes provided in the mounting plate in order to overcome these drawbacks, the manufacturing process for these parts will become extremely time-consuming. There was also the disadvantage that the cost of the product increased significantly.

The present invention has been proposed to overcome the drawbacks of the prior art as described above. That is, in the present invention, the mounting plate is formed by a spring plate bent in a dogleg shape, and in this bent state, the distance between each shaft hole drilled in the mounting plate is set to be the same as that of each gear inserted into the spring plate. When installing each gear on the mounting plate, the spacing between the spindles should be narrower than the spacing between the spindles.If you want to install each gear on the mounting plate, extend the bent mounting plate to widen the spacing between the shaft holes, and insert the spindles of each gear into the expanded shaft holes. After that, the elasticity of this mounting plate elastically biases the spindles of each gear in the direction of narrowing the gap between them, thereby preventing backlash between the gears. Our goal is to provide the following.

The present invention will now be explained in detail based on the embodiments shown in FIGS. 2 and 3.

Reference numeral 20 in the figure is a mounting plate, and this mounting plate is formed from an elastic spring plate material. The entire mounting plate is bent in a dogleg shape when viewed from the side, and there are two shaft holes at both ends of the mounting plate.
1 and 22 are perforated. This shaft hole 21, 22
When the mounting plate 20 is in a bent state, the distance 1 is smaller than the distance L between the support shafts of the gears attached to the mounting plate 20. For example, a notch 23 is formed in the center of the mounting plate 20.
3, the mounting plate 20 can be easily changed into a bent state or a flat state.

To attach each gear to such a mounting plate 20, proceed as follows. That is, the mounting plate bent in a dogleg shape is stretched out into a flat plate shape against its elasticity, and the distance between the shaft holes 21 and 22 bored at both ends of the mounting plate is widened. Then, the shaft hole 21 in this expanded state,
The support shaft of the drive gear 3 and the support shaft of the hydra gear 4 are inserted into 22. At the same time as inserting each support shaft,
The tips of the teeth of each gear should also mesh with each other. If the mounting plate 20 is released in this state, the mounting plate 20 will be bent into a dogleg shape from the center notch 23, and the distance between the shaft holes 21 and 22 drilled in the mounting plate will be narrowed, and this shaft The distance between the support shafts of the drive gear 3 and the idler gear 4 is also narrowed as they are attracted to the hole. As a result, the meshing of the teeth of the drive gear 3 and the idler gear 4 becomes strong, and the backlash between the two gears is eliminated.

Note that the present invention is not limited to the above-described embodiment, and for example, the notch 23 may not be provided by simply bending the mounting plate 20 into a dogleg shape on the side. Alternatively, the notch 23 may be deep enough to approach the opposite side edge of the mounting plate 20, and the mounting plate 20 may be bent in advance in a direction such that the width of the notch 23 changes. . In such a case, when the width of the notch 23 is narrowed, the mounting plate 20
The distance between the shaft holes 21 and 22 drilled in the shaft is also narrowed, and if the width of the notch 23 is widened and the support shaft is fitted,
The width of the notch 23 tends to narrow due to the elasticity of the mounting plate, thereby tightening the respective shaft holes 21 and 22 to prevent crushing.

As shown in the above embodiments, according to the mechanism of the present invention, after each gear is attached to the mounting plate, the spacing between the spindles of each gear is narrowed by the elasticity of this mounting plate. The tips of the teeth of each gear are pressed against each other by this mounting plate, and as a result, crushing between the gears is effectively prevented. In particular, the pitch error of each gear and the shaft holes 21 and 22 provided in the mounting plate
Even if there are variations in the spacing between the gears, the elasticity of the mounting plate allows the tips of the teeth of each gear to mesh strongly, making it possible to maintain standard production accuracy of the gears and mounting plate while also preventing unevenness between each gear. It is possible to prevent this. As described above, according to the present invention, it is possible to effectively prevent backlash in the rotational force transmission mechanism between the tuning shaft and the core slide in the pushbutton tuner, which also has the effect of eliminating frequency deviation of the tuner.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a backlash prevention mechanism of a conventional push button tuner, and FIGS. 2 and 3 are perspective views showing a backlash prevention mechanism of the present invention.
FIG. 2 shows the state before the mounting plate is attached, and FIG. 3 shows the state after the mounting plate is attached. 1...Synchronized shaft, 2...Drive gear, 3...Idler gear, 4...Driven gear, 5...Wormshaft, 6...Worm, 7...Worm wheel, 8...Bottom plate, 9...Core Slide, 10...
Rack, 11... Core, 12... Coil, 20...
...Mounting plate, 21, 22...Shaft hole, 23...Notch.

Claims (1)

[Scope of utility model registration request] In the rotational force transmission mechanism installed between the tuning shaft of the push button tuner and the core slide driven by it, the support shafts of a pair of mutually meshing gears are located in the shaft holes formed at both ends of the mounting plate. Rotatably insert the
In addition, this mounting plate is formed of a spring plate, and is bent before the support shaft of each gear is attached, so that the spacing between the shaft holes formed at both ends of the mounting plate matches the support shaft of each gear to be attached to it. A push-button tuner crash prevention mechanism characterized in that the spacing is narrower than the spacing.