Tactile membrane keyboard with asymmetrical tactile key elements

Claim 2

A tactile snap action switch element comprising: a sheet of base material; and at least one snap action protrusion having a first wall segment and a second wall segment formed in said sheet of base material, said protrusions being asymmetric with respect to a center axis thereof or a plane containing said center axis.

Claim 3

A tactile snap action switch element as in claim 1 wherein: said protrusion has a first section in the shape of a portion of a surface of revolution, and at least one second section in a shape different from said first section.

Claim 4

A tactile snap action switch element as in claim 1 wherein: said protrusion has a first section in the shape of a portion of a truncated cone, and at least one second section in a shape different from said first section.

Claim 5

A tactile snap action switch element as in claim 3 wherein: said second section is an elongated ramp intersecting said first section.

Claim 6

A keyboard comprising: a sheet of base material; a plurality of tactile elments formed in said sheet of base material, each of said tactile elements being a protrusion in said base material, each of said protrusions having a first wall segment and a second wall segment, said protrusions being asymmetric with respect to a center axis thereof or a plane containing said center axis; first electrically conductive means associated with each tactile element; and second electrically conductive means aligned with each of said tactile elements, said first electrically conductive means contacting said second electrically conductive means to complete an electric circuit upon actuation of each of said tactile elements.

Claim 7

A keyboard comprising: a sheet of base material; a plurality of tactile elments formed in said sheet of base material, each of said tactile elements being a protrusion in said base material, each of said protrusions having a first wall segment and a second wall segment, said protrusions being asymmetric with respect to a center axis thereof or a plane containing said center axis; first electrically conductive means associated with each tactile element; and second electrically conductive means aligned with each of said tactile elements, said first electrically conductive means contacting said second electrically conductive means to complete an electric circuit upon actuation of each of said tactile elements.

Claim 8

A keyboard as in claim 5 wherein: each of said tactile elements has a first section in the shape of a portion of a surface of revolution, and at least one second section in a shape different from said first section.

Claim 9

A keyboard as in claim 5 wherein: each of said tactile elements has a first section in the shape of a portion of a truncated cone, and at least one second section in a shape different from said first section.

Claim 10

A keyboard as in claim 7 wherein: said second section is an elongated ramp intersecting said first section.

Claim 11

A keyboard as in claim 5 wherein: said first electrically conductive means is a contact on said tactile element.

Claim 12

A keyboard as in claim 5 wherein: said first electrically conductive means is sheet means spaced from said tactile element.

Claim 13

A keyboard as in claim 5 wherein: said first electrically conductive means is conductive elastomer means spaced from said tactile element.

Claim 14

A keyboard as in claim 5 further including: overlay means positioned over said tactile elements.

Claim 15

A keyboard as in claim 12 wherein: said overlay means is an electroluminescent panel.

Claim 16

A keyboard as in claim 12 wherein: said overlay means is an embossed cover sheet.

Claim 17

A tactile snap action switch element comprising: a sheet of base material; and at least one snap action protrusion formed in said sheet of base material, said protrusion having a first wall section which is part of a surface of revolution about an axis and a second wall section which is other than a surface of revolution about said axis, whereby said protrusion is asymmetric with respect to said axis or a plane containing said axis.

Claim 18

A tactile snap action switch element comprising: a sheet of base material; and at least one snap action protrusion formed in said sheet of base material, said protrusion having a first wall section which is part of a surface of revolution about an axis and a second wall section which is other than a surface of revolution about said axis, whereby said protrusion is asymmetric with respect to said axis or a plane containing said axis.

Claim 19

A tactile snap action switch element as in claim 15 wherein: said first section is in the shape of a portion of a truncated cone, and said second section is a segment of shape different from said first section.

Claim 20

A tactile snap action switch element as in claim 16 wherein: said second section is an elongated ramp intersecting said first section.

Claim 21

A keyboard comprising: a sheet of base material; a plurality of tactile elements formed in said sheet of base material, each of said tactile elements being a protrusion in said base material, said protrusion having a first wall section which is part of a surface of revolution about an axis and a second wall section which is other than a surface of revolution about said axis, whereby said protrusion is asymmetric with respect to said axis or a plane containing said axis; first electrically conductive means associated with each tactile element; and second electrically conductive means aligned with each of said tactile elements, said first electrically conductive means contacting said second electrically conductive means to complete an electric circuit upon actuation of each of said tactile elements.

Claim 22

A keyboard comprising: a sheet of base material; a plurality of tactile elements formed in said sheet of base material, each of said tactile elements being a protrusion in said base material, said protrusion having a first wall section which is part of a surface of revolution about an axis and a second wall section which is other than a surface of revolution about said axis, whereby said protrusion is asymmetric with respect to said axis or a plane containing said axis; first electrically conductive means associated with each tactile element; and second electrically conductive means aligned with each of said tactile elements, said first electrically conductive means contacting said second electrically conductive means to complete an electric circuit upon actuation of each of said tactile elements.

Claim 23

A keyboard as in claim 18 wherein: said first section is in the shape of a portion of a truncated cone, and said second section is a segment of shape different from said first section.

Claim 24

A keyboard as in claim 19 wherein: said second section is an elongated ramp intersecting said first section.

Claim 25

A keyboard as in claim 18 wherein: said first electrically conductive means is a contact on said tactile element.

Claim 26

A keyboard as in claim 19 wherein: said first electrically conductive means is sheet means spaced from said tactile element.

Claim 27

A keyboard as in claim 18 wherein: said first electrically conductive means is conductive elastomer means spaced from said tactile element.

Claim 28

A keyboard as in claim 18 further including: overlay means positioned over said tactile elements.

Claim 29

A keyboard as in claim 24 wherein: said overlay means is an electroluminescent panel.

Claim 30

A keyboard as in claim 24 wherein: siad overlay means is an embossed cover sheet.