JPH04282803A - Serration shaft - Google Patents

Abstract

PURPOSE:To eliminate an excess stress to a body side in which a serration shaft is mounted. CONSTITUTION:A serration shaft 1 to be used as a coupling shaft is made of resin, its head side is formed as a bottomed hollow cylinder, divided into one half 2 and the other half 3 by a split groove 21, and both are coupled by a bottom 4. Serration teeth 7, 8 are respectively formed on one half 2 and the other half 3. Since the groove 21 is wide, the teeth 7, 8 formed on the one and the other halves 2, 3 are reduced, a contact area of them with other component to be engaged therewith is largely reduced. Thus, since the other component can be simply mounted when the other component is mounted on the shaft, a stress to a movable shaft coupled to the serration shaft can be reduced at the time of mounting.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serration shaft suitable for use as a connecting shaft to a movable shaft of a volume.

0002

[Prior Art] When using a rotating electronic component such as a volumetric volume, a knob is usually attached to its movable shaft.
The rotary electronic components are adjusted using knobs. Depending on the type of volume, there are those that allow the knob to be inserted directly into the movable shaft, but there are also those that allow the knob to be attached via a connecting shaft such as a serration shaft.

[0003] Serration shaft 1 used as a connecting shaft
As shown in FIGS. 4, 5 and 6, it is a hollow bottomed cylindrical body with an open head, and one half 2 and the other half are separated by a groove 5 formed along its axis. It is divided into 3. The purpose of the split grooves 5 is to impart predetermined elasticity to the one half 2 and the other half 3, respectively.

A predetermined number of teeth 7, 8 are formed on the circumferential surface of each of the one half 2 and the other half 3. Both teeth 7 and 8 have a serration configuration (therefore, hereinafter referred to as serration teeth), and the illustrated example shows an 18-serration shaft. In FIG. 4, 4 is the bottom and 6 is the shaft hole.

The serration shaft 1 includes a long shaft type as shown in FIG. 5 and a short shaft type as shown in FIG. As electronic devices become smaller and flatter, rotating electronic components (volumes, etc.) used in them are also becoming smaller and flatter. Along with this, short-shaft type serration shafts have come into widespread use.

FIG. 7 shows a conventional example in which a short shaft type serration shaft 1 is used as a connecting shaft to a movable shaft of a volume. In the figure, 11 is a printed circuit board,
The volume 10 is placed and fixed on this. volume 1
0 has a main body 12 in a flat shape, and a plurality of terminals 13 are led out from the upper surface side, and these are connected to a printed circuit board 11.
to be soldered.

Reference numeral 14 denotes a movable shaft for adjusting the resistance value, and the serration shaft 1 having the above-mentioned short shaft structure is attached and fixed to the upper end of the movable shaft by screws 15. A cylindrical columnar knob 16 with an open bottom is fitted onto the outer periphery of the serration shaft 1. 18 is a panel of an electronic device, and a knob 16 is attached to the serration shaft 1 so as to slightly protrude from the panel 18.

[0008] With this configuration, the knob 1
6 is transmitted to the movable shaft 14 via the serration shaft 1, the resistance value can be adjusted to an arbitrary value. The serration shaft 1 having a short shaft configuration is not only applied as a connecting shaft of the volume 10. Needless to say, it can also be used as a connecting shaft for other rotating electronic components.

[0009]

[Problems to be Solved by the Invention] By the way, as the rotating electronic component used in the serration shaft 1 becomes lighter, thinner, and smaller, if the load applied to the movable shaft becomes slightly too large, the rotating electronic component Damage to elements within the body often occurs. For example, taking the above-mentioned volume 10 as an example, when the knob 16 is pushed in to fit it into the serration shaft 1, the serration teeth 7 and 8 and the serration teeth 17 of the knob 16 shown in FIG. If the meshing state is not correct, an excessive load will be applied to the movable shaft 14 via the serration shaft 1, and if the load at that time is deviated from the axial direction, the load may cause damage to the inside of the volume body 12, for example. There was a risk of damaging the attached resistive film (not shown).

[0010] This is because (1) the serration shaft 1 is made of metal; and (2) it has a short shaft structure, so even if the split groove 5 is formed, there is a slight elasticity between the one half 2 and the other half 3. The reason for this is that it cannot be granted. Therefore, if the meshing state of the serration teeth 6, 7 and 17 is poor, the serration shaft 1
The impact will be immediately transmitted to the movable shaft 14.

[0011] Therefore, the present invention solves these problems, and even with a serrated shaft having a short shaft configuration, the meshing state of the shaft is made smooth so that the impact (stress) is not transmitted to other parts. It is something.

0012

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a serration shaft with a short shaft configuration, in which one half is separated by a relatively large groove formed parallel to the axis. It is characterized in that it is divided into two halves, the number of teeth formed on the outer periphery of each of these halves is limited, and that it is molded from synthetic resin.

[0013]

[Operation] As shown in FIG. 2, the serration shaft 1 is divided into one half 2 and the other half 3 by a relatively large groove 21 formed parallel to the axis. Due to this split groove 21, the number of serration teeth 7, 8 formed on the outer periphery of these one half 2 and the other half 3 is significantly smaller than in the conventional configuration.

The serration shaft 1 is molded from synthetic resin. Therefore, due to this large split groove 21, the number of teeth that mesh with the serration teeth 17 of the knob 16 is significantly smaller than before, and since the serration shaft 1 is made of resin, one half 2 and the other half 3 are Gives some elasticity. For these reasons, the knob 16 can be smoothly inserted into the serration shaft 1, so that no large impact is applied to the movable shaft 14 during insertion and insertion, and the knob 16 can be smoothly attached.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a case in which an example of the serration shaft according to the present invention is applied to the above-mentioned volume connection shaft will be described in detail with reference to the drawings.

FIG. 1 is a front view of a serration shaft 1 according to the present invention, and FIG. 2 is a plan view thereof. As is clear from both figures, the present invention also has a short-axis configuration based on a hollow bottomed cylindrical body with an opening on the head side. In this invention, the grooves 21 are formed considerably wider than the conventional grooves 5. The reason for this wide split groove configuration is that (1) the fitting area (meshing area) between the serration shaft 1 and the knob 16 should be as small as possible; and (2) the split groove 21 allows the serration shaft 1 to be as small as possible.
This is based on reasons such as wanting to add elasticity to the material.

The dividing groove 21 is formed parallel to the axis of the cylindrical body, thereby dividing the cylindrical body into one half 2 and the other half 3, which are connected by the bottom 4. split groove 2
1 has a depth that reaches the bottom 4, and serration teeth 7, 8 similar to the conventional one are formed on the outer periphery of each of the one half 2 and the other half 3. Therefore, although a total of 18 serration teeth 7, 8 would normally be formed on the outer periphery of the cylindrical body, the number of serration teeth 7, 8 is significantly reduced because the width of the dividing groove 21 is wide.

In the case shown in FIG. 2, serration teeth 7,
8 is an example of four cases. Serration teeth 7, 8
The number of teeth varies depending on how the tooth pitch is selected, but at least the number of teeth must be such that when the knob 16 is attached as described later, there will be no slippage between the knob 16 and the serration shaft 1. . In the case of an 18-serration shaft, if the number of serrations is as shown in the figure, no slippage will occur.

When the width of the dividing groove 21 is selected so that the number of teeth is 4 on an 18-serration shaft, one half of the width is 2.
The opening angle from the axis of each of the other half portions 3 is approximately 80 degrees. The width of the groove 21 shown in FIG. 2, the number of serration teeth 7 and 8 formed in the one half 2 and the other half 3, etc. are examples.

The serration shaft 1 according to the present invention is not made of metal but of resin. That is, the serration shaft 1 is molded from a synthetic resin (such as Duracon (trade name)). Made of resin, even the short shaft type has split groove 2.
This is to allow a certain degree of elasticity (flexibility) to be imparted to one half part 2 and the other half part 3 in combination with the wide configuration of part 1.

Now, when the serration shaft 1 constructed as described above is used as a connecting shaft for the volume 10, it becomes the same as shown in FIG. However, the fitted state between the serration shaft 1 and the knob 16 is as shown in FIG. Figure 3
As is clearer, the engagement area of the serration shaft 1 with the knob 16 is considerably smaller than in the conventional case (see FIG. 8).

[0022] As a result, even if the knob 16 and the serration shaft 1 do not mesh well, they can be quickly restored to a normal state of engagement, and the one half 2 and the other half 3 of the serration shaft 1 have a certain degree of Because of its elasticity, it will be biased even slightly in the axial direction, so even if the engagement between the two is poor, the knob 16 can be inserted into the serrated shaft 1 without applying excessive insertion force to the serrated shaft 1. Can be fixed. That is, the knob 16 can be smoothly attached to the serration shaft 1 with a slight force, and as a result, excessive stress is not applied to the movable shaft 14, so that the resistive film inside the main body 12 can be reliably protected.

Although the present invention uses the serration shaft 1 as a connecting shaft to the movable shaft 14 provided in the volume 10, the rotary electronic components to which it can be applied are not limited.

[0024]

As described above, the serrated shaft according to the present invention is made of resin, and the number of teeth is greatly reduced by making the grooves larger.

[0025] According to this, the contact area with other parts attached to the serration shaft is significantly reduced compared to the conventional one, so the meshing state of the other parts and the serration shaft becomes smooth, and the other parts can be attached to the serration shaft with less force. parts can be inserted into the serration shaft. Therefore, no extra impact is transmitted to the movable shaft, and even if the mechanical strength of the rotating electronic component used is low, it has practical effects such as eliminating the risk of damaging the elements inside the main body. .

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of a serrated shaft according to the present invention.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a sectional view of the serration shaft in use.

FIG. 4 is a plan view of a conventional serration shaft.

FIG. 5 is a front view of a long shaft type serration shaft.

FIG. 6 is a front view of a short shaft type serration shaft.

FIG. 7 is a cross-sectional view when the serration shaft is used as a volume connection shaft.

8 is a partial cross-sectional view centered on the serration axis of FIG. 7. FIG.

[Explanation of symbols]

1 Serration shaft 2 One half part 3 Other half part 4 Bottom part 5, 21 Division grooves 7, 8, 17 Teeth (serration teeth) 10 Volume 14 Movable shaft 16 Knob

Claims (1)

[Claims] [Claim 1] A serration shaft having a short shaft configuration,
It is divided into one half and the other half by a relatively large groove formed parallel to the axis, and the number of teeth formed on the outer periphery of these one half and the other half is limited,
A serrated shaft characterized by being molded from synthetic resin.