DE8530029U1 - Foil switching arrangement - Google Patents

Description

Wilhelm Ruf JKG. _f Höhenkirchen, 1S ₄ 10.1985 J | /

Schwanthaiei; street \ h \ i » ] * $$ *

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8000 Munich 2 83-6

Foil switching arrangement

description

The invention relates to a membrane switch arrangement, in particular flat keyboards, with a pressure point according to the preamble of claim 1.

There are known foil-circuit arrangements in which the coated conductors and switch contact surfaces printed circuit board level a sheet of flexible ,, electrically non-conductive material is arranged, from which the Be ^Ä the switch contact surfaces tabs rich stamped free and obliquely upwardly angled shown. Contact materials are applied in the area of the free tab ends. Above this film provided with contact tabs is a switching film, also called a decorative film, in which dome-shaped actuating elements are formed. By pressing down on the actuating surface, the free shelf, which protrudes at an angle, is

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beautiful with its lower conductive contact surface pressed onto the assigned switching contact surfaces of the circuit board * Due to the inherent elasticity of the flexible, Electrically non-conductive foil lift the tab ends from the switch contact surfaces after the actuating surface has been left free the circuit board. Such membrane switch arrangements have a pressure point and can also be used for flat keyboards, however, they are relatively expensive because the molding of foils is difficult from a production point of view and only with the most modern production facilities is controllable * Another disadvantage is the deep formation of the "bubbles", because it means the service life is limited.

The object of the invention is to improve the foil circuit arrangement of the type mentioned above that a Foil switching arrangement with pressure point, which in particular 'for flat keyboards for ultrasonic and infrared remote control devices of entertainment electronics, for the "operation of projection devices as well as for small electrical computers is to be used, can be produced economically with high quality with relatively simple manufacturing facilities is. According to the invention, this object is achieved by the features indicated in the characterizing parts the protection claims 1 and 2 solved.

The invention is explained below using two exemplary embodiments in conjunction with drawings:

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It shows:

Figure 1 is a sectional view of the foil switch assembly along the line A-A according to the invention;

FIG. 2 shows a three-dimensional representation of a flat keyboard with a membrane switch cabinet;

FIG. 3 shows a sectional representation of an individual switching element of the foil switching arrangement along the Line B-B;

FIG. 4 shows a sectional view of the switching element of the foil switching arrangement along the line B-B in actuated state;

FIG. 5 shows a sectional illustration of a variant of the foil switch arrangement.

The same reference numerals designated in the individual figures denote the same individual parts of the foil switching arrangement .

FIG. 1 shows the sectional view of several switching elements of the membrane switching arrangement of a flat keyboard. Of the Carrier 5 can be made of electrically non-conductive material or of metal. On this carrier is one made of silicone rubber or thermoplastic existing elastic Schaltkontakfcmatie 3 arranged. The one on this overlying flexible, electrically non-conductive film

is on its lower side 11 with a ladder and switch pad configuration made of conductive paint or metal. On the upper level of the film 12, the control buttons 7 are positioned in the keypad frame 8 with tolerance play.

FIG. 2 shows a three-dimensional representation of a complete flat keyboard. The actuation surfaces of the f
Keys 7 positioned in the keypad frame 8 with tolerance play can be designed to be completely flat, convex or concave, depending on the customer's requirements.

FIG. 3 shows a sectional illustration along the line B-B of an individual switching element of the foil switching arrangement. The elastic switch contact mat marked with 3 lies with its circular surface 1 on the Level 4 of the carrier 5, the contact plate 6 is on the inner surface 26 of the integrally formed switching dome 2 and is the one with switching contact surfaces and conductor tracks 13 provided lower level 11 of the flexible, facing electrically non-conductive film 12. The film 12 rests on the upper surface 27 of the conical upwardly widening switching dome 2 of the elastic switching contact mat 3. Above the film 12 there are webs in section of the keypad frame 8 and the key 7 positioned with tolerance play, which can be operated in the downward direction of the arrow is presented, layed out. By combining slide 12 and switching contact Eiatte 3, a pressure point can be felt when the individual switching elements are actuated.

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FIG. 4 shows the individual switching element described under FIG. 3, shown in section B-B, in the switching position. When the button 7 is pressed in the direction of the arrow, the film 12 is pressed downwards so that the switch contact surfaces 10 electrically connect to the contact plate 6.

S The sectional view CC (Figure 5) shows a variant & of the foil switching arrangement with the characterizing features of protection claims 2. In this embodiment ι

example is an elastic switching mat 14 without contact I

sj plate 6 is provided. The flexible, electrically non- | conductive film 16 is in this variant on their upper; side 17 coated with switch contact surfaces 18 and conductor tracks 19. A spacer film or insulating layer 20, also called a spacer, rests on this coated plane in order to prevent the contact surface 22 of the decorative film 23 from making undesired contact with the contact surfaces 18 of the film 16. Operating symbols (not shown) are applied to the upper level 25 of the decorative film 23. When one of the operating symbols is actuated in the direction of the arrow, the actuating force is counteracted by the force of the intrinsic elasticity of the switching mat 14 and brings the contact surface 22 of the decorative film 23 through the opening 21 of the spacer film or insulating layer 20 with the cores. surfaces 18 of the film 16 electrically connected, after the operating symbol is left open, the three films 16/20 and 23 / are

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switched state are locally arched through the force of the inherent elasticity of the switching mat 14 in their
Rest positions pushed back. The task of the switching mat 14 is to ensure that the contact surfaces 22 and 18 are reliably closed and opened with a noticeable pressure point and a long service life.

Claims (4)

Wilhelm Ruf'fcd ";: .J.". . goSfeiikirchen, October 15, 1985 SchwanthalefcsereiYe Λ8: ..: *: ^ Ärß. Munich 2 83-6 slides - switching arrangement protection claims 1. Foil switching arrangement, especially for flat keyboards with a support on which on the upper level an elastic switch contact mat is arranged with a lying on it, one-sided with conductor tracks and Switching contact surfaces coated, flexible, non-conductive Foil and a keypad arranged on the upper layer of the foil, characterized in that that the circular surfaces (1) of the downward sloping switch domes (2) of the elastic switch contact mat (3) on the upper level (4) of the carrier (5) rest that the electrically conductive contact plate (6) within the integrally formed switching domes (2) are arranged and when serving the flat, convex or concave shaped keys (7) in the direction of the arrow, which are positioned in the keypad frame (8> are held, with the switch contact surfaces (10) on the lower Surface (11) of the flexible, electrically non-conductive film (12) arranged conductor tracks (13) and switching contact surfaces (10) are electrically connected. 2. Foil switching arrangement according to claim 1, characterized characterized in that an elastic switching mat (14) without a contact plate (6) is used, * t HH HiI Il Il * · * «· · t 1 t I t * * * 4 * ·« «* * Il 4 ·« S t, f »-» · »· - i er r · [T are arranged with a resting on the switching mat top side (15) flexible, electrically non-conductive film (16) on the upper side (17) of the switching contact surfaces (18) and conductor tracks (19) having thereon a spacer film or insulating layer (20), through whose opening (21) the ai; The contact surface (22) applied to the lower surface (24) of the decorative film (23) comes into electrical connection with the contact surfaces (18) when the decorative film (23) is actuated in the direction of the arrow. 3. Foil switching arrangement according to claim 1 and 2, d a -characterized in that the on the lower and upper surfaces (11) and (17) of the flexible, electrically non-conductive foils (12, 16) are switch contact surfaces (10, 18) and conductor tracks (13, 19) made of electrically conductive paint or metal. 4. Switching arrangement according to claim 1 and 2, characterized in that the elastic switch contact mat (3) and elastic switch mat (14) Silicone rubber or thermoplastic.