JPH02265122A - Switch board - Google Patents

Abstract

PURPOSE:To improve switching reliability and obtain a low-cost switch board by projecting the surface of a conductive pattern portion from the surface of insulating synthetic resin. CONSTITUTION:After a metallic thin-plate 3 of good conductivity has the projected portion 4 formed with half die cutting, etc., from material on a flat plate, it is buried in a switch board 1 with insert mold forming to place the exposed surface of the projected portion 4 in a projected state from the surface of the switch board 1. A flat plate portion 5 of the metallic thin-plate 3 is buried so as to be sandwiched between upper and lower resins. Accordingly, the conductive face of a contact brush is cleaned because abrasive powder is chipped out of the contact brush. It is thus possible to realize reliable switching and obtain a low-cost switch board 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a contact type switch board that performs switching by sliding on a contact brush in electronic equipment parts.

[Prior art] A conventional switch board of this type was manufactured by Jitsushin Kosho 63-138
As disclosed in No. 6, the surfaces of the conductive part and the insulating part were placed at the same position.

For example, in the conventional switch board, as shown in FIG. 9, a protrusion 14 is formed and the protrusion of a punched thin metal plate 15] 4 or the entire surface is plated, and the thin metal plate 15 is formed into a switch board made of insulating synthetic resin. 15, the surface of the protrusion 14 was placed in the same position as the surface of the switch board 16.

[Problems to be Solved by the Invention] However, in the conventional system, when the contact brush 17 and the conductive pattern 18 come into contact with each other due to the rotation of the switch board in the direction of the arrow, as shown in FIG. The friction of 19 causes wear of each part, and abrasion powder of the contact brush and abrasion powder of the switch board adhere to the tip of the contact brush 17 (around the contact part with the switch board). In this state, if there is moisture or oil, the adhesion to the contact brush 17 will be further promoted. This abrasion powder 20 is mainly made of insulating synthetic resin and has high insulating properties. In such a state, the contact brush 17
When attempting to establish conduction with the conduction pattern 18, the abrasion powder 20 obstructs the conduction, resulting in poor conduction such as chattering.

Further, as shown in FIG. 11, when the conductive pattern 18 is located below the surface of the switch board 19, the insulating synthetic resin of the switch board covers the conductive pattern 18 due to frictional force, and a predetermined conductive time width is obtained. This problem occurred along with the above-mentioned problem and caused poor continuity.

The present invention has been made to solve these drawbacks, and its purpose is to improve the switching reliability of the switch board. Another object of the present invention is to provide such a switch board at a low cost.

[Means for Solving the Problems] The present invention provides a switch board in which the conductive part is made of a thin metal plate in which a protruding part and a flat plate part are formed, and the metal plate is embedded in an insulating synthetic resin. Alternatively, in a switch board made of a synthetic resin having conductivity and an insulating synthetic resin formed by forming a protrusion on the synthetic resin and covering the protrusion with the protrusion left, the conductive pattern part is made of an insulating synthetic resin. It is characterized by protruding from the resin surface.

[Embodiment] As an embodiment of the present invention, a rotary switch board used for detecting the position of a type wheel in a printer, detecting the number of revolutions in a counter, etc. will be explained.

FIG. 1 is a plan view and a sectional view showing an embodiment of the present invention. In the figure, 1 is a disk-shaped switch board made of insulating synthetic resin, and 2 is a center hole of the switch board 1. 3
is a thin metal plate with good conductivity, and protrusions 4 corresponding to the conductive pattern are formed by half-cutting or the like.

The thin metal plate 3 is formed with a protruding part 4 by half-cutting or the like from a flat material 7': After that, it is buried in the switch board 1 by insert molding, and the surface of the exposed protruding part 4 is attached to the surface of the switch board 1. The thin metal plate 3 is disposed in a more protruding state, and the flat plate portion 5 of the thin metal plate 3 is buried in the upper and lower resin layers in a sandwich-like manner.

FIG. 2 is a plan view and a sectional view showing another embodiment of the present invention. In the figure, 5 is a disk-shaped switch board made of insulating synthetic resin, and 6 is a center hole of the switch board 5. Reference numeral 7 is made of a conductive synthetic resin, and a protrusion 8 corresponding to the conductive pattern is formed therein.

The conductive synthetic resin 7 is molded to form a protrusion 8 and then buried in the switch board 5 by two-color molding, so that the exposed surface of the protrusion 8 protrudes from the surface of the switch board 5. Conductive synthetic resin 7
is buried in a sandwich-like manner between upper and lower insulating synthetic resin layers.

Another method for making the conductive pattern surface protrude from the switch board surface is to form a protrusion 8 on the conductive synthetic resin 7 by molding, as shown in the cross-sectional view of the embodiment in FIG.
It is buried in the switch board 5 by two-color molding, and the exposed surface of the protrusion 8 is placed at an arbitrary position with respect to the surface of the switch board 5, and the conductive synthetic resin 7 is buried in a sandwich shape between upper and lower insulating synthetic resins. Then, metal plating 9 is applied to the conductive synthetic resin 7 to make the conductive pattern surface protrude.

4, FIG. 5, FIG. 6, and FIG. 7 are enlarged views showing examples of the protruding shape of the conductive pattern surface of FIG. 3.

In FIG. 4, the surface of the protrusion 8-a of the conductive synthetic resin 7-a is located below the surface of the switch board 5, and the conductive pattern surface is made to protrude by plating 9.

In FIG. 5, the surface of the protrusion 8-b of the conductive synthetic resin 7-b is located on the same plane as the surface of the switch board 5, and the conductive pattern surface is made to protrude by the plating 9.

In FIG. 6, the surface of the protruding portion 8-c of the conductive synthetic resin 7-c is chamfered to make the conductive pattern surface protrude.

In FIG. 7, the surface of the protruding portion 8-d of the conductive synthetic resin 7-d is rounded so that the conductive pattern surface protrudes.

In this way, the present invention contemplates the case where the conductive pattern surface protrudes from the switch substrate surface by any method.

FIG. 8 is an enlarged sectional view showing the switching state of the switch board and contact brush of the present invention.

FIG. 8 (al) shows the state before the contact brush 11 is switched to the switch board conductive pattern 10.

In the figure, reference numeral 13 indicates abrasion powder of the contact brush 11 and abrasion powder of the switch board 12 caused by friction between the contact brush 11 and the switch board 12 as the switch board 12 rotates in the direction of the arrow. This abrasion powder 13 is further encouraged to adhere to the contact brush 11 if there is warm air, oil, or the like. This wear powder 13 is mainly made of insulating synthetic resin and has high insulating properties. In this state, when the contact brush 11 shown in FIG. 8(b) starts to come into contact with the conductive pattern 10,
Since the conductive pattern 19 protrudes from the switch board 12 portion, the abrasion powder 13 is scraped off from the contact brush 11, and the conductive surface of the contact brush 11 becomes clean. This allows reliable switching.

FIG. 8(C) is a diagram showing this state.

As an embodiment of the present invention, a rotary switch board used for detecting the position of a type wheel in a printer, the number of revolutions in a counter, etc. has been described, but the same applies to a sliding switch board.

[Effects of the Invention] As described above, according to the present invention, when the contact brush and the conductive pattern come into contact with each other due to the rotation of the switch board as in the conventional system, friction between the contact brush and the switch board causes wear of various parts. Abrasion powder of the contact brush and abrasion powder of the switch board are at the tip of the contact brush (around the contact area with the switch board)
It is possible to prevent conduction from being hindered by highly insulating abrasion particles that are attached to the surface of the wire or further promoted by moisture, oil, etc., resulting in poor conduction such as chattering.

Furthermore, it is also possible to prevent the problem of the insulating synthetic resin of the switch board covering the conduction pattern due to frictional force and preventing a predetermined conduction time width from being obtained when the conduction pattern portion is located below the surface of the switch board. This can greatly improve the switching reliability of the switch board. Furthermore, such a switch board can be provided at low cost.

As described above, the present invention has great effects and can be utilized for contact-type switch boards that perform switching by sliding on contact brushes in electronic equipment parts.

[Brief explanation of drawings]

FIG. 1 is a plan view and a sectional view showing an embodiment of a switch board of the present invention. FIGS. 2 and 3 are plan and cross-sectional views showing another embodiment of the switch board of the present invention. 4, FIG. 5, FIG. 6, and FIG. 7 are enlarged views showing examples of the protruding shape of the conductive pattern surface of FIG. 3. FIG. 8 is an enlarged sectional view showing the switching state of the switch board and contact brush of the present invention. FIG. 9 is a diagram showing a conventional example. FIG. 10 and FIG. 11 are diagrams showing conventional problems. Switch board metal thin plate protrusion switch board conductive synthetic resin protrusion metal plating conduction pattern contact brush switch board abrasion powder Applicant Seiko Epson Co., Ltd. Agent Patent attorney Kizobe Suzuki and 1 other person C] Figure (^ ) Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 (8) (shi) Figure 9 (-111

Claims (1)

[Claims] 1. In a switch board in which the conductive part is made of a thin metal plate on which a protruding part and a flat plate part are formed, and the metal plate is embedded in an insulating synthetic resin, the surface of the conductive pattern part is insulated. A switch board characterized by protruding from a synthetic resin surface. 2. In a switch board made of a synthetic resin having electrical conductivity and an insulating synthetic resin formed by forming a protrusion on the synthetic resin and leaving the protrusion and covering it, the surface of the conductive pattern part is made of an insulating material. A switch board characterized by protruding from a synthetic resin surface.