Keyboards switch assembly with multilayer pattern contact means

Claim 2

In a keyboard the combination of a circuit board supporting a plurality of electrically conductive pathways, a separator positioned upon the top of said board and conductive pathways and having a plurality of openings in register with seleCted portions of said pathways, the improvement comprising an elastomeric layer having adhered thereto and supported thereby for movement therewith a plurality of nonselfsupporting flexible conductive plastic contactors, said conductive plastic contactors comprising a plastic binder and electrically conductive particles dispersed therein, said contactors positioned over said openings so that pressure selectively applied to said elastomeric layer forces selected ones of said contactors through selected openings into contact with said selected portions of said pathways and release of said pressure permits the elastomeric layer to return to its original shape while pulling the contactors adhered thereto away from the pathways.

Claim 3

In a keyboard according to claim 1 in which a plurality of non-selfsupporting flexible conductive plastic interconnecting members are adhered to and supported by the elastomeric layer and are coupled to selected ones of said contactors.

Claim 4

In a keyboard according to claim 2 in which the conductive plastic is of a non-elastomeric material.

Claim 5

In a keyboard according to claim 3 in which the conductive plastic has silver particles dispersed.

Claim 6

In a keyboard according to claim 2 in which the interconnecting members are at least partially out of register with said openings.

Claim 7

In a keyboard according to claim 2 in which the thickness of the contactors and interconnecting members is at least about 5 times less than the thickness of the elastomeric layer.

Claim 8

In a keyboard according to claim 6 in which the contactors and interconnecting members are less than 0.788 mil in thickness and in which the elastomeric layer is between 5 to 200 mils in thickness.

Claim 9

In a keyboard according to claim 7 in which the conductive plastic is of a non-elastomeric material.

Claim 10

In a keyboard according to claim 1 in which a plurality of said contactors are electrically connected together by a non-selfsupporting flexible conductive plastic interconnecting element means adhered to and supported by said elastomeric layer, said plastic interconnecting element means comprising a plastic binder and electrically conductive particles dispersed theren.

Claim 11

In a keyboard according to claim 1 in which the plastic binder is a polyamide resin and silver particles are dispersed therein.

Claim 12

In a keyboard according to claim 9 in which the plastic binder is a polyamide resin and silver particles are dispersed therein.

Claim 13

In a keyboard which includes an insulator board having circuit pathways thereon, insulator means having a plurality of windows therethrough in alignment with selected portions of the pathways, a plurality of nonselfsupporting contactors spaced apart and each positioned for passage through one of said windows and supported by an elastomeric layer to which it is adhered, said contactor means comprising a flexible electrically conductive plastic material physically adhered to said elastomeric layer, said conductive plastic material comprising a plastic binder and electrically conductive particles dispersed therein and pressure application means for forcing said contactors through said windows to cause said contactors to electrically contact portions of said pathways, said elastomeric layer being thick enough to keep said contactors away from said pathway portions in the absence of pressure applied to pressure application means and for pulling said contactors away with it from said pathways after application and the release of pressure to said pressure application means and said contactors being thick enough to provide electrical conductivity while not being so flexible to separate from the elastomer layer upon being flexed in continuous use.

Claim 14

In a keyboard which includes an insulator board having circuit pathways thereon, insulator means having a plurality of windows therethrough in alignment with selected portions of the pathways, a plurality of nonselfsupporting contactors spaced apart and each positioned for passage through one of said windows and supported by an elastomeric layer to which it is adhered, said contactor means comprising a flexible electrically conductive plastic material physically adhered to said elastomeric layer, said conductive plastic material comprising a plastic binder and electrically conductive particles dispersed therein and pressure application means for forcing said contactors through said windows to cause said contactors to electrically contact portions of said pathways, said elastomeric layer being thick enough to keep said contactors away from said pathway portions in the absence of pressure applied to pressure application means and for pulling said contactors away with it from said pathways after application and the release of pressure to said pressure application means and said contactors being thick enough to provide electrical conductivity while not being so flexible to separate from the elastomer layer upon being flexed in continuous use.

Claim 15

In a keyboard according to claim 12 in which the contactors are non-elastomeric.

Claim 16

In a keyboard according to claim 13 in which the contactors are 0.197 mil to 1.0 mils in thickness.

Claim 17

In a keyboard according to claim 14 in which the elasTomeric layer is 5 to 200 mils in thickness.

Claim 18

In a keyboard according to claim 13 in which the contactors are 0.197 to 1.969 mil in thickness.

Claim 19

In a keyboard according to claim 16 in which the elastomeric layer is 10 to 100 mils in thickness.

Claim 20

In a keyboard according to claim 12 in which the contactors are of a lesser thickness than the non-conductive elastomeric layer with the elastomeric layer being of a thickness at least about 5 times that of the conductive layer to provide the elasticity to pull the contactors back with it after being depressed and the contactors being thick enough to provide electrical conductivity.

Claim 21

In a keyboard according to claim 18 in which the contactors are of a thickness less than 1 mil.

Claim 22

In a keyboard according to claim 18 in which said binder is polyamide resin and said particles are silver.

Claim 23

In a keyboard according to claim 12 in which the contactors are of a thickness less than 0.788 mil.

Claim 24

In a keyboard according to claim 12 in which the volume resistivity of the contactors is less than 10 ohm centimeters.

Claim 25

In a keyboard according to claim 22 in which the volume resistivity is less than 1 ohm centimeter.

Claim 26

In a keyboard according to claim 23 in which the volume resistivity is less than 0.5 ohm centimeters.

Claim 27

In a keyboard according to claim 12 including a plurality of flexible conducting plastic members adhered to said elastomeric layer and selectively coupled to at least two said plurality of contactors.

Claim 28

In a keyboard according to claim 25 in which the contactors and the interconnecting members are of a nonelastomeric material.

Claim 29

In a keyboard according to claim 25 in which said binder is polyamide resin and said particles are silver.

Claim 30

In a keyboard according to claim 12 in which said binder is polyamide resin and said particles are silver.