Low profile tactile switch

• US 5,828,016 A
• Filed: 02/03/1997
• Issued: 10/27/1998
• Est. Priority Date: 02/12/1996
• Status: Expired due to Fees

• Current Assignee: Lucas Automation & Control Engineering, Inc.
• Original Assignee: Lucas Automation & Control Engineering, Inc.
• Inventors: Thompson, David W., Grannan, Dennis A.
• Primary Examiner(s): Friedhofer, Michael A.
• Application Number:
  US08/794,650
• Time in Patent Office: 631 Days
• Field of Search: 200/1 R, 200/1 A, 200/5 R, 200/5 A, 200/17 R, 200/18, 200/512-517, 200/341, 200/520, 200/405, 200/406, 200/16 R-16 D, 29/622
• US Class Current: 200/16.00R
• CPC Class Codes: H01H 11/00 Apparatus or processes specially adapted for the manufacture of electric switches processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88
• CPC Class Codes: H01H 13/02 Details
• CPC Class Codes: H01H 13/48 using buckling of disc springs
• 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 2205/034 with snap action
• CPC Class Codes: H01H 2209/026 metallic
• CPC Class Codes: H01H 2209/07 metallic
• CPC Class Codes: H01H 2229/028 Adhesive
• CPC Class Codes: H01H 2229/056 Laminating
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

A low profile tactile switch including a conductive member having a dome profile and lead means, a conductive contact member having a contact and lead means and an insulating member arranged between the conductive member and the contact member but allowing contact between the members upon actuation of the dome profile, wherein the switch may be mass produced from rolls of flat material.

Claims

1. A low profile switch comprising:

a conductive tactile member formed from a thin metal strip and being self-supporting,

a conductive contact member, and

an insulator between said members,

said tactile conductive member having a collapsible tactile portion,

said contact member having a contact portion engageable by said collapsible tactile portion when it is forced to collapse,

said insulator being formed from a thin plastic film having a layer of pressure-sensitive adhesive on at least one side for adhesively connecting said film to said tactile conductive member,

said contact member being carried by the insulator which electrically insulates the contact member from the tactile conductive member, and

lead means for said tactile conductive member and said contact member for connection of the switch into a circuit,

whereby application of a tripping force to said collapsible tactile portion of said tactile conductive member causes the collapsible tactile portion to collapse and contact said contact member to close the circuit, and release of the tripping force allows the collapsible tactile portion to return to its normal state and open the circuit.

2. The switch of claim 1, wherein said plastic film further includes a layer of pressure-sensitive adhesive on the other side for adhesively connecting to said contact member.

3. The switch of claim 2, wherein said contact member is in the form of a plate having the contact portion disposed in opposed relation to said tactile conductive member.

4. The switch of claim 3, wherein an opening is formed in said plastic film through which the tactile conductive member can pass to engage the contact portion of said plate.

5. The switch of claim 4, wherein the contact portion projects from said plate towards said collapsible tactile member and into said opening.

6. The switch of claim 1, wherein said tactile conductive member has a thickness of about 0.002 to 0.010 inch, and said insulator has a thickness of about 0.002 to 0.012 inch.

7. The switch of claim 6, wherein said contact member is in the form of a plate having a thickness of about 0.002 to 0.020 inch.

8. The switch of claim 1, wherein said collapsible tactile portion is dome-shaped.

9. The switch of claim 1, wherein said contact member is in the form of a pin having a head on one end defining the contact portion.

10. The switch of claim 9, wherein said pin further includes a shoulder spaced from said head and coacting with the head to retain the pin in a hole formed in the insulator.

11. The switch of claim 1, wherein said plastic film is a polymer.

12. The switch of claim 1, wherein said polymer is a polyester.

13. The switch of claim 1, wherein said polymer is a polycarbonate.

14. The switch of claim 1, wherein said polymer is a polyimide.

15. The switch of claim 1, wherein said conductive tactile member is dome-shaped.

16. The switch of claim 1, wherein said lead means includes leads extending from each of said members.

17. The switch of claim 1, which includes a plurality of conductive tactile members for controlling a single circuit.

18. The switch of claim 1, which includes a plurality of conductive tactile members for controlling a plurality of circuits.

19. A low profile tactile switch consisting essentially of:

a self-supporting movable contact formed from a thin conductive material and including a tactile portion,

an insulator formed from thin plastic film, pressure sensitive adhesive on at least one of the movable contact or the insulator for adhesively connecting said insulator to said movable contact,

and a stationary contact mounted on said insulator opposite from and contactable with said tactile portion and insulated from said movable contact.

20. The switch of claim 19, wherein the thickness of the movable contact is in the range of 0.002 to 0.010 inch.

21. The switch of claim 20, wherein the thickness of the insulator is in the range of 0.002 to 0.012 inch.

22. The switch of claim 19, which further includes leads extending from the contacts for connection in a circuit.

23. The switch of claim 22, which further includes tab means extending from said movable contact and grippingly engaging said insulator.

24. The switch of claim 19, wherein the plastic film is a polycarbonate.

25. The switch of claim 19, wherein the plastic film is a polyimide.

26. The switch of claim 19, wherein the stationary contact member is in the form of a planar plate.

27. The switch of claim 19, wherein the stationary contact member is in the form of a pin having a head on one end contactable with said movable contact.

28. A low profile tactile switch consisting essentially of:

a first self-supporting movable contact of thin conductive material including a tactile portion,

a second stationary contact disposed in opposed relation to said tactile portion and being contactable thereby,

and insulator means separating and electrically insulating the contacts from each other, said insulator means including adhesive means interconnecting said contacts.

29. The switch of claim 28, wherein the insulator means includes a layer of pressure-sensitive adhesive.

30. The switch of claim 28, wherein said insulator means includes a plastic film on which pressure-sensitive adhesive has been applied to at least one side.

31. The switch of claim 30, wherein pressure-sensitive adhesive has been applied to both sides of the film.

32. The switch of claim 28, wherein the insulator means includes a layer of pad-printed adhesive.

33. The method of making a low profile tactile switch consisting essentially of a first conductive contact member, a second conductive contact including a self-supporting conductive tactile member, and an insulator disposed between said members,

said method comprising the steps of:

incrementally feeding a metal strip along one line to a punch press having a set of dies for stamping a dome formation in said metal strip to form the tactile member,

incrementally feeding to a punch press having a set of dies to make the insulator for the switch an insulator strip along the same line and the insulator strip having a pressure-sensitive adhesive on at least one side,

feeding the metal strip to join the adhesive side of the insulator strip along the same line,

mounting a contact member to the insulator for engagement by said tactile member upon actuation thereof, and

severing the metal strip and insulator to form the switch.

34. A method of making low profile tactile switches having a thin upper conductive member with a tactile dome and lead means, a thin lower conductive member having a contact and lead means wherein the contact opposes the tactile dome, and a thin insulating member between said conductive members with pressure-sensitive adhesive on both sides and an opening therethrough in alignment with said dome and contact,

said method comprising the steps of:

incrementally feeding a first conductive metal strip to means forming tactile domes therein,

incrementally feeding a second conductive metal strip to means forming contacts in the second strip,

incrementally feeding a strip of electrical insulating material having pressure-sensitive adhesive on both sides covered with peelable release layers to means forming openings in the insulating material strip,

peeling away the release layers from the insulating material,

joining said first and second metal strips to opposite sides of the insulating material to form a switch strip wherein the domes and contacts align with each other and with the openings in the insulating material,

incrementally feeding the switch strip to means forming leads on said first and second metal strips, and

severing the switch strip between each aligned dome and contact to form individual switches.

35. The method of claim 34, wherein the means forming the tactile dome in the first strip includes a punch press having a set of dies.

36. The method of claim 35, wherein the means forming the contacts in the second strip includes a punch press having a set of dies.

37. The method of claim 36, wherein the means forming the openings in the insulating material strip includes a punch press having a set of dies.

38. A method of making low profile tactile switches having a thin upper conductive member with a tactile dome and lead means, a thin insulating member connected to the upper conductive member having a hole therethrough aligned with the dome, and a pin member mounted on said insulating member having a shank extending through the hole, a contact on one end of the shank engageable by said dome when it is collapsed, and lead means on the other end of the shank,

said method comprising the steps of:

incrementally feeding a conductive strip to means forming tactile domes therein,

incrementally feeding the conductive strip to means forming lead legs and locking tab legs adjacent the domes,

incrementally feeding an insulating strip having pressure-sensitive adhesive on one side covered by a peelable release strip to means forming a pin hole for the contact pin,

peeling away the release strip,

incrementally feeding the insulating strip to means for inserting contact pins in said pin holes,

incrementally feeding the conductive strip and insulating strip in joined registry with each other so that domes align with pins,

incrementally feeding the joined strips to means bending the lead legs to leads extending substantially perpendicular to the plane of the strips and bending and crimping the locking tab legs about edges of the insulating strip from switches, and

severing the switches from the strips to form individual switches.