Tactile element and keyboard including the tactile element

Claim 2

A tactile snap action electrical switch element comprising: a sheet of base material; and at least one snap action protrusion formed in and extending from said sheet of base material, said protrusion having first and second arcuately shaped domes of different radii, the surface of said second dome being smooth and uninterrupted and the surface of said first dome being smooth and interrupted only at the circular junctions with the sheet of base material and the second dome, said first dome extending from and being integral with said sheet of base material, said second dome extending from and being integral with said first dome, said first dome being at least partly inverted by applying a pressure against said second dome, said second dome having a smaller radius than said first dome, the ratio of the radius of said second dome to that of the first dome being selected such that said second dome will not be inverted by said applied pressure, said second dome being a non-invertible actuator for said first dome.

Claim 3

A tactile switch element as in claim 1 wherein: said second dome extends from the center of said first dome.

Claim 4

A tactile switch element as in claim 2 wherein: each of said first and second domes is a portion of a sphere.

Claim 5

A tactile switch element as in claim 3 wherein: said first dome is a portion of a sphere of larger radius than said second dome.

Claim 6

A tactile switch element according to claim 4 wherein: the radius, R, of the first dome is in the range of between 0.2 and 1.0 inches; the height, H, of the first dome is in the range of between 0.010 and 0.100 inches; the radius, r, of the second dome is in the range of between 0.030 and 0.125 inches; the height, h, of the second dome is in the range of between 0.010 and 0.060 inches; and the thickness, t, of the element is in the range of between 0.002 and 0.007 inches.

Claim 7

A snap action electrical switch element which is capable of being inverted by an actuation force to provide tactile feedback, the element having a sheet of base material, and at least one snap action protrusion formed in said base material, said protrusion having a first domed contour and a second domed contour, said first domed contour being invertible to provide tactile feedback and said second domed contour resisting inversion when the actuation force is imposed upon the element.

Claim 8

A snap action electrical switch element which is capable of being inverted by an actuation force to provide tactile feedback, the element having a sheet of base material, and at least one snap action protrusion formed in said base material, said protrusion having a first domed contour and a second domed contour, said first domed contour being invertible to provide tactile feedback and said second domed contour resisting inversion when the actuation force is imposed upon the element.

Claim 9

A switch element according to claim 6 wherein said second domed contour extends from the center of said first domed contour.

Claim 10

A switch element as in claim 7 wherein: each of said domed contours is a portion of a sphere.

Claim 11

A switch element as in claim 8 wherein: said first domed contour is a portion of a sphere of larger radius than said second domed contour.

Claim 12

A switch element according to claim 8 wherein: the radius, R, of the first dome is in the range of between 0.2 and 1.0 inches; the height, H, of the first dome is in the range of between 0.010 and 0.100 inches; the radius, r, of the second dome is in the range of between 0.030 and 0.125 inches; the height, h, of the second dome is in the range of between 0.010 and 0.060 inches; and the thickness, t, of the element is in the range of between 0.002 and 0.007 inches.

Claim 13

A tactile snap-action key which is movable between an opened and closed position to open and close an electrical circuit, said key comprising: a sheet of base material; a tactile element formed in said sheet of said base material and including a first arcuately shaped invertible dome and a dome actuating protrusion means, said dome actuating protrusion means being a second arcuately shaped dome which is integral with and extending from said first dome, said first dome being inverted by applying a pressure against said second dome, said second dome having a smaller radius than said first dome, the ratio of the radius of said second dome to the radius of the first dome being selected such that said second dome will not be inverted by said applied pressure, said first dome providing for tactile feedback when it is inverted, the surface of said second dome being smooth and uninterrupted and the surface of said first dome being smooth and interrupted only by the circular junctions with said sheet of base material and the second dome; first conductive means being associated with said first dome; and second conductive means, said second conductive means being aligned with and facing said first conductive means, the actuation of the key providing said applied pressure against said second dome which at least partly inverts said first dome establishing electrical contact between said first conductive means and said second conductive means.

Claim 14

A tactile snap-action key which is movable between an opened and closed position to open and close an electrical circuit, said key comprising: a sheet of base material; a tactile element formed in said sheet of said base material and including a first arcuately shaped invertible dome and a dome actuating protrusion means, said dome actuating protrusion means being a second arcuately shaped dome which is integral with and extending from said first dome, said first dome being inverted by applying a pressure against said second dome, said second dome having a smaller radius than said first dome, the ratio of the radius of said second dome to the radius of the first dome being selected such that said second dome will not be inverted by said applied pressure, said first dome providing for tactile feedback when it is inverted, the surface of said second dome being smooth and uninterrupted and the surface of said first dome being smooth and interrupted only by the circular junctions with said sheet of base material and the second dome; first conductive means being associated with said first dome; and second conductive means, said second conductive means being aligned with and facing said first conductive means, the actuation of the key providing said applied pressure against said second dome which at least partly inverts said first dome establishing electrical contact between said first conductive means and said second conductive means.

Claim 15

A key according to claim 11 wherein said first conductive means comprises a printed circuit formed on the surface of said first dome and said second conductive means comprises a printed circuit positioned in alignment with said first conductive means to provide for electrical contact between the first and second printed circuits when said first dome is inverted.

Claim 16

A tactile key as in claim 11 wherein: said second dome extends from the center of said first dome.

Claim 17

A tactile key as in claim 13 wherein: each of said first and second domes is a portion of a sphere.

Claim 18

A tactile key as in claim 14 wherein: said first dome is a portion of a sphere of larger radius than said second dome.

Claim 19

A tactile key as in claim 15 wherein: the radius, R, of the first dome is in the range of between 0.2 and 1.0 inches; the height, H, of the first dome is in the range of between 0.010 and 0.100 inches; the radius, r, of the second dome is in the range of between 0.030 and 0.125 inches; the height, h, of the second dome is in the range of between 0.010 and 0.060 inches; and the thickness, t, of the element is in the range of between 0.002 and 0.007 inches.

Claim 20

A keyboard comprising: a flexible first sheet of printed circuitry having a plurality of tactile elements, each element including a first arcuately shaped dome which is integral with and extends outwardly from said first sheet and a dome actuating protrusion means which is integral with and extends from said first dome, said dome actuating protrusion means being a second arcuately shaped dome, said first and second domes meeting at a circular junction and having smooth uninterrupted surface contours, said first dome being at least partly inverted by applying a pressure against said second dome, said second dome having a smaller radius than said first dome, said radius of said second dome being sufficiently less than the radius of said first dome to prevent inversion of said second dome by said applied pressure; a portion of printed circuitry carried by each of said first domes; and circuit means aligned with said tactile elements and retained with respect to said first sheet, the printed circuit portions carried by said first domes contacting the circuit means when each of said first domes is partly inverted.

Claim 21

A keyboard comprising: a flexible first sheet of printed circuitry having a plurality of tactile elements, each element including a first arcuately shaped dome which is integral with and extends outwardly from said first sheet and a dome actuating protrusion means which is integral with and extends from said first dome, said dome actuating protrusion means being a second arcuately shaped dome, said first and second domes meeting at a circular junction and having smooth uninterrupted surface contours, said first dome being at least partly inverted by applying a pressure against said second dome, said second dome having a smaller radius than said first dome, said radius of said second dome being sufficiently less than the radius of said first dome to prevent inversion of said second dome by said applied pressure; a portion of printed circuitry carried by each of said first domes; and circuit means aligned with said tactile elements and retained with respect to said first sheet, the printed circuit portions carried by said first domes contacting the circuit means when each of said first domes is partly inverted.

Claim 22

A keyboard according to claim 17 wherein the circuit means comprises a second sheet of printed circuitry, the printed circuitry on the first sheet being selectively insulated from the printed circuitry of the second sheet to allow connection of the printed circuitry only when the domes are inverted.

Claim 23

A keyboard according to claim 18 wherein said first sheet of printed circuitry comprises a sheet having printed circuitry on one surface thereof and said second sheet comprises a sheet of printed circuitry having printed circuitry on one surface thereof, said first and second sheets being aligned so that the printed circuitry of the first sheet faces the printed circuitry of the second sheet, said printed circuitry of the first sheet being separated from the printed circuitry of the second sheet by insulating means, said insulating means including a plurality of apertures aligned with said first domes to allow for contact of the first printed circuitry with the second printed circuitry when said first domes are inverted.

Claim 24

A keyboard as in claim 17 wherein: said second dome extends from the center of said first dome.

Claim 25

A keyboard as in claim 20 wherein: each of said first and second domes is a portion of a sphere.

Claim 26

A keyboard as in claim 21 wherein: said first dome is a portion of a sphere of larger radius than said second dome.

Claim 27

A keyboard as in claim 22 wherein: the radius, R, of the first dome is in the range of between 0.2 and 1.0 inches; the height, H, of the first dome is in the range of between 0.010 and 0.100 inches; the radius, r, of the second dome is in the range of between 0.030 and 0.125 inches; the height, h, of the second dome is in the range of between 0.010 and 0.060 inches; and the thickness, t, of the element is in the range of between 0.002 and 0.007 inches.