Tactile membrane keyboard with asymmetrical tactile key elements

• US 4,492,829 A
• Filed: 02/13/1984
• Issued: 01/08/1985
• Est. Priority Date: 02/25/1982
• Status: Expired due to Fees

• Current Assignee: Flex-Key Corporation
• Original Assignee: Rogers Corporation (Rogers Communications Inc.)
• Inventors: Rodrique, Leo J.
• Primary Examiner(s): Scott, J. R.
• Application Number:
  US06/579,814
• Time in Patent Office: 330 Days
• Field of Search: 200/5 R, 200/5 A, 200/83 R, 200/83 N, 200/86 R, 200/159 B, 200/275, 200/292, 200/314, 200/317, 200/329
• US Class Current: 200/5.00A
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 2209/002 Materials
• CPC Class Codes: H01H 2209/078 Conductive rubber
• CPC Class Codes: H01H 2215/022 Asymmetric; Elliptic; Square
• CPC Class Codes: H01H 2217/01 Off centre actuation
• CPC Class Codes: H01H 2217/018 Indication of switch sites
• CPC Class Codes: H01H 2229/028 Adhesive

Abstract

A tactile or snap action membrane keyboard is presented wherein the tactile or snap action key elements are protrusions in a membrane sheet, the protrusions being asymmetrical to preprogram the collapse of the tactile element.

Claims

1. 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.

2. 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.

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 truncated cone, and at least one second section in a shape different from said first section.

4. A tactile snap action switch element as in claim 3 wherein:

said second section is an elongated ramp intersecting said first section.

5. 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.

6. 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.

7. 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.

8. A keyboard as in claim 7 wherein:

said second section is an elongated ramp intersecting said first section.

9. A keyboard as in claim 5 wherein:

said first electrically conductive means is a contact on said tactile element.

10. A keyboard as in claim 5 wherein:

said first electrically conductive means is sheet means spaced from said tactile element.

11. A keyboard as in claim 5 wherein:

said first electrically conductive means is conductive elastomer means spaced from said tactile element.

12. A keyboard as in claim 5 further including:

overlay means positioned over said tactile elements.

13. A keyboard as in claim 12 wherein:

said overlay means is an electroluminescent panel.

14. A keyboard as in claim 12 wherein:

said overlay means is an embossed cover sheet.

15. 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.

16. 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.

17. A tactile snap action switch element as in claim 16 wherein:

said second section is an elongated ramp intersecting said first section.

18. 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.

19. 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.

20. A keyboard as in claim 19 wherein:

said second section is an elongated ramp intersecting said first section.

21. A keyboard as in claim 18 wherein:

said first electrically conductive means is a contact on said tactile element.

22. A keyboard as in claim 19 wherein:

said first electrically conductive means is sheet means spaced from said tactile element.

23. A keyboard as in claim 18 wherein:

said first electrically conductive means is conductive elastomer means spaced from said tactile element.

24. A keyboard as in claim 18 further including:

overlay means positioned over said tactile elements.

25. A keyboard as in claim 24 wherein:

said overlay means is an electroluminescent panel.

26. A keyboard as in claim 24 wherein:

siad overlay means is an embossed cover sheet.