Two-position latching two dome switch

• US 5,622,254 A
• Filed: 04/18/1996
• Issued: 04/22/1997
• Est. Priority Date: 04/18/1996
• Status: Expired due to Fees

• Current Assignee: Packard Hughes Interconnect Company
• Original Assignee: Packard Hughes Interconnect Company
• Inventors: Lee, James S.
• Primary Examiner(s): Walczak, David J.
• Application Number:
  US08/633,264
• Time in Patent Office: 369 Days
• Field of Search: 200/557, 200/553, 200/561, 200/339, 200/512, 200/515, 200/516, 200/5 R, 200/1 B, 200/5 E, 200/17 R, 200/318, 200/318.1, 200/320, 200/323
• US Class Current: 200/557
• CPC Class Codes: H01H 21/18 Movable parts; Contacts mounted thereon
• CPC Class Codes: H01H 2221/018 Tumbler
• CPC Class Codes: H01H 23/12 Movable parts; Contacts mounted thereon
• CPC Class Codes: H01H 23/28 with three operating positions
• CPC Class Codes: H01H 5/30 by buckling of disc springs

Abstract

The invention includes a keycap having a top surface having a first and second end, and a body portion, said keycap being pivotally connected to a support for movement of the keycap from a first to a second position. A lever extending downward from the body portion of the keycap. The lever is sandwiched between and constantly engaged by a first and second opposed dome structures. Each dome structure has a conductive material on the underside thereof and the dome structure is supported on a substrate having an open circuit. In the first position for the keycap a first dome structure is collapsed and the electrically conductive element on the undersurface of the dome engages the open circuit to close the circuit. When the keycap is moved to a second position, the keycap pivots causing the lever to move in a rotational direction collapsing the second dome structure and said first dome structure biases the lever against the second dome structure. The present invention is simple in construction and low cost and provides improved tactile field over prior art latching switches.

Claims

1. A two-position latching two dome switch comprising:

a switch control member body having a portion pivotally connected to a support for movement of the member from a first position to a second position;

first and second nonmetallic, flexible domes each having an electrically conductive element carried in the underside of the dome, said domes each being mounted on a support having first and second sets of spaced-apart conductive traces thereon, each of said domes being constructed and arranged to continually engage a portion of said switch control member;

whereby upon movement of said switch control member to a first position, said member collapses said first dome causing said conductive element under said first dome to engage a first set of spaced-apart conductive traces closing a circuit associated therewith and said second dome is completely extended and engages said member to latch said switch control member in said first position wherein said first dome is collapsed, and upon movement of said switch control member to said second position said member pivots to collapse said second dome causing said electrically conductive element under said second dome to engage a second set of spaced-apart electrical traces and close a circuit associated therewith and so that said first dome is fully extended and engages said member to latch said switch control member in said first position and wherein said second dome is collapsed.

2. A two-position latching two dome switch as set forth in claim 1 wherein said switch control member comprises a substantially rectangular keycap having a top surface with first and second ends each being depressible to cause said keycap to move from one of a first and a second position.

3. A two-position latching two dome switch as set forth in claim 1 wherein said switch further comprises a pedestal extending upwardly from said body portion.

4. A two-position latching two dome switch as set forth in claim 1 further comprising a lever extending downward from said body portion and wherein said first and second dome engage opposite sides of the lever.

5. A two-position latching two dome switch as set forth in claim 1 wherein said support is a substantially flat substrate.

6. A two-position latching two dome switch as set forth in claim 1 wherein said support is a U-shaped member and said domes are position to face each other.