JPH052941A - Switch base board - Google Patents

Abstract

(57) [Abstract] [Objective] In a switch substrate formed of a conducting part 1 and a non-conducting part 2, by improving the wear resistance of a contact brush that makes elastic contact with the switch substrate, the reliability of switching is improved. With the goal. [Constitution] On the surface of a switch substrate, there is a wall-shaped portion provided between contact brushes, and it is possible to supply and retain lubricating oil for each contact brush. [Effect] The wear resistance of the contact brush is improved, and the switching reliability is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact-type switch substrate which slides on and off a contact brush to be used for position detection of a printing wheel of a printer and rotation speed detection of a counter.

[0002]

2. Description of the Related Art An example of a switch substrate of this type has been disclosed in Japanese Utility Model Publication No. 63-1386, but a rotary switch generally used for detecting the position of a printing wheel of a printer is
It is required to have extremely good wear resistance. FIG. 5 shows a switch of this kind, namely, a rotary shaft 8 for driving the type wheel 7.
A disk-shaped substrate 9 is attached to the rotary shaft 8, and a contact brush 11 made of a metal piece having good conductivity is elastically contacted with a switch pattern 10 on the substrate 9 which rotates at a high speed together with the rotating shaft 8 to rotate the type wheel 7. An example of a high-speed rotary switch for detecting is shown.

[0003]

However, the rotary switch substrate used for detecting the position of the type wheel of the printer, detecting the number of revolutions in the counter, etc. is a contact brush and a brush for high speed rotation (several thousands rpm). Friction of the switch substrate is remarkable, and conduction failure such as chattering becomes a problem.

Lubricating oil is applied to the switch substrate as a countermeasure against this wear, but the lubricating oil is scattered due to the high speed rotation, and a sufficient effect cannot be obtained. The manner in which the lubricating oil is scattered will be described with reference to FIG. FIG. 6 is an enlarged view of a contact portion of a conventional switch substrate, showing a state in which lubricating oil 6 is applied to the switch substrate as a measure against wear. Since the switch substrate rotates at high speed, the lubricating oil 6 on the surface moves or scatters to the outer periphery and the outside of the switch substrate due to centrifugal force, and the contact brush 5
Had reduced the lubrication effect of.

The present invention has been made to solve such a drawback, and an object thereof is to improve the reliability of switching of a switch substrate.

[0006]

SUMMARY OF THE INVENTION The present invention provides a contact mechanism having a switch substrate having a plurality of switch patterns formed of a conductor portion and a non-conductor portion, and a contact brush that elastically slides on the switch pattern. In this case, a wall-shaped portion is provided on the outer periphery of the sliding surface on which the contact brush of the switch substrate slides.

[0007]

According to the above-mentioned structure of the present invention, since the wall-shaped portion provided on the contact brush sliding surface of the switch substrate can prevent the scattering of lubricating oil and have an oil retaining effect as an oil reservoir, Brush wear is reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 to 4 of a rotary switch substrate used for detecting the position of a printing wheel of a printer, detecting the number of rotations of a counter, and the like. 1 is a front view of the switch substrate, and FIG. 2 is a cross-sectional view taken along the line AOA of FIG.

FIG. 3 shows the contact position of the contact brush, and FIG.
FIG. 6 is a diagram showing a contact state between a switch board and a contact brush.

Reference numeral 15 is a disk-type switch substrate composed of a conductive part 1 with plating and a non-conductive part 2 without plating. Reference numeral 3 is a central hole in which the switch substrate is fixed to a shaft that is rotationally driven. The conduction pattern is formed by embossing a protrusion corresponding to the conduction pattern of the conduction part 1 with a copper material, and then insert-molded so as to be formed into a sandwich shape with a synthetic resin of polyacetal, and further exposed to the surface of the protrusion. It is formed by applying a metal of good conductivity such as gold or silver. The wall-shaped portion 4 is provided on the switch substrate 15 with each contact brush 5
Is a projecting shape provided on the outer periphery of the sliding surface of and is integrally formed of synthetic resin that forms a non-conducting portion during insert molding. Reference numeral 5 is a contact brush made of nickel silver and elastically contacting the switch substrate 15, and the inside is a common brush. Reference numeral 6 is a lubricating oil applied to the sliding surface of the switch substrate 15.

The switch board 15 constructed as described above.
Is rotated at high speed around the center hole 3. The lubricating oil 6 moves in the outer peripheral direction by the centrifugal force of the rotation of the switch substrate 15, but is not scattered by being blocked by the wall-shaped portion 4 due to the partial movement of the contact brush sliding surface. Lubricate the surface. Due to the oil retaining effect, the friction coefficient between the contact brush 5 and the switch substrate 15 can be reduced and abrasion can be prevented.

Thus, from the point of view of the present invention, whatever the shape of the wall, the present invention is intended as long as it is aimed at the oil retaining effect.

[0013]

As described above, according to the present invention, the wall-shaped portion provided on the switch substrate enhances the oil retaining effect and suppresses the abrasion of the switch substrate and the contact brush when sliding. The switching reliability of the switch substrate can be significantly improved. As described above, the effect of the present invention is great, and the present invention can be utilized for a contact-type switching substrate that performs switching by sliding with a contact brush in an electronic device.

[Brief description of drawings]

FIG. 1 is a front view of a switching board according to the present invention.

FIG. 2 is a cross-sectional view taken along the line AOA of FIG.

FIG. 3 is a diagram showing a contact position of the contact brush of the present invention.

FIG. 4 is a diagram showing a contact state between a switch substrate and a contact brush of the present invention.

FIG. 5 is a diagram showing an example of a conventional high-speed rotation switch.

FIG. 6 is a diagram showing a surface state of a conventional switch substrate.

[Explanation of symbols]

 1 Conduction Part 2 Non-Conduction Part 3 Center Hole 4 Wall Shape Part 5 Contact Brush 6 Lubricating Oil 7 Type Wheel 8 Rotating Axis 9 Switch Board 10 Switch Pattern 11 Contact Brush 15 Switch Board

Claims (1)

Claims: 1. A contact mechanism having a switch substrate having a plurality of switch patterns formed of a conductor portion and a non-conductor portion, and a contact brush having a contact brush that slidably contacts and slides on the switch pattern. And a wall-shaped portion is provided on the outer periphery of a sliding surface of the switch substrate on which the contact brush slides.