Low travel switch assembly

• US 10,262,814 B2
• Filed: 08/08/2016
• Issued: 04/16/2019
• Est. Priority Date: 05/27/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hendren, Keith J., Wilson, Jr., Thomas W., Brock, John M., Leong, Craig C., Niu, James J., Okuma, Satoshi, Watanabe, Shinsuke
• Primary Examiner(s): Lee, Kyung S
• Application Number:
  US15/230,740
• Publication Number:
  US 20160343523A1
• Time in Patent Office: 981 Days
• Field of Search: 200512, 200513, 200517
• CPC Class Codes: H01H 13/14 Operating parts, e.g. push-button
• CPC Class Codes: H01H 13/48 using buckling of disc springs
• CPC Class Codes: H01H 13/52 the contact returning to its original state immediately upon removal of operating force, e.g. bell-push switch
• CPC Class Codes: H01H 13/70 having a plurality of operating members associated with different sets of contacts, e.g. keyboard mounting together a plurality of independent switches H02B
• CPC Class Codes: H01H 13/85 characterised by tactile feedback features
• CPC Class Codes: H01H 2215/004 Collapsible dome or bubble
• CPC Class Codes: H01H 2223/042 mounted in conventional keyboard
• CPC Class Codes: H01H 2229/05 Forming; Half-punching
• CPC Class Codes: H01H 65/00 Apparatus or processes specially adapted to the manufacture of selector switches or parts thereof
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing

Abstract

A low travel switch assembly and systems and methods for using the same are disclosed. The low travel dome may include a domed surface having upper and lower portions, and a set of tuning members integrated within the domed surface between the upper and lower portions. The tuning members may be operative to control a force-displacement curve characteristic of the low travel dome.

Claims

1. A switch assembly, comprising:

a key cap;

a domed surface disposed below the key cap and defined by an array of arms connecting a central portion of the domed surface to an outer edge of the domed surface; and

an electrical membrane coupled to the domed surface opposite the key cap and operative to trigger a switch event, the electrical membrane comprising a top layer and a bottom layer, each of the top and bottom layers being coupled to a corresponding conductive gel, the conductive gel providing support to the key cap and the domed surface when the key cap displaces toward the electrical membrane,

wherein the array of arms is operative to;

maintain an offset between the central portion and the electrical membrane when the electrical membrane is not triggering the switch event; and

control the domed surface to operate according to a predefined force-displacement curve.

2. The switch assembly of claim 1, wherein one of the array of arms is disposed transverse to another of the array of arms.

3. The switch assembly of claim 1, wherein the domed surface comprises a substantially square base.

4. The switch assembly of claim 3, wherein the substantially square base includes at least one angled edge.

5. The switch assembly of claim 1, wherein at least two of the array of arms are separated by a cutout formed into the domed surface.

6. A low travel dome, comprising:

a domed surface having upper and lower portions, the domed surface comprising;

an array of radially-distributed arms extending between the upper and lower portions, the array of radially-distributed arms operative to control a force-displacement curve characteristic of the low travel dome, each of the arms of the array of radially-distributed arms having a length and a lateral thickness that is constant along at least a portion of the length.

7. The low travel dome of claim 6, wherein the force-displacement curve characteristic corresponds to a change in force required to displace the upper portion.

8. The low travel dome of claim 6, wherein:

the array of radially-distributed arms has a height dimension and a width dimension; and

the force-displacement curve characteristic is based on at least one of the height and the width dimension.

9. The low travel dome of claim 6, wherein:

the array of radially-distributed arms has a stiffness; and

the force-displacement curve characteristic is based on the stiffness.

10. The low travel dome of claim 6, wherein the array of radially-distributed arms provides tactile feedback to a user according to the force-displacement curve characteristic.

11. The low travel dome of claim 6, wherein one of the array of radially-distributed arms intersects another of the array of radially-distributed arms at the upper portion.

12. The low travel dome of claim 11, wherein the intersection of the one of the array of radially-distributed arms and the another of the array of radially-distributed arms defines a cross-shaped portion.

13. The low travel dome of claim 6, wherein the lower portion comprises one of a circle, a polygonal, a square, or an elliptical shape.

20. The low travel dome of claim 6, wherein the radially-distributed arms are separated from each other by an array of L-shaped openings in the domed surface.

14. A method for manufacturing a low travel dome, comprising:

providing a dome-shaped surface having a top portion and a bottom portion; and

selectively removing an array of predefined portions of the dome-shaped surface between the top portion and the bottom portion, thereby defining an array of arms connecting the top portion and the bottom portion,

wherein;

a shape of each of the array of arms defines a force-displacement curve characteristic of the low travel dome; and

the array of arms defines a cross-shaped portion of the dome-shaped surface, the array of arms each having substantially straight side edges in the cross-shaped portion of the dome-shaped surface.

15. The method of claim 14, wherein selectively removing comprises forming openings at the array of predefined portions, each of the openings having a predefined shape.

16. The method of claim 15, wherein the predefined shape is one of an L-shape or a wedge shape.

17. The method of claim 15, wherein:

each of the array of arms has a width dimension; and

the width dimension is defined by the predefined shape of the openings.

18. The method of claim 17, wherein the force-displacement curve characteristic is based on the width dimension.

19. The method of claim 14, wherein the selectively removing comprises one of cutting out or stamping out the array of predefined portions.