# US 4,490,587 A · Switch assembly

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,490,587 A
- Document ID: US4490587A
- Status: Granted
- Kind: A
- Application number: 06/482,832
- Filed: 1983-04-07
- Granted: 1984-12-25
- Earliest claimed: 1983-04-07
- Assignees: Microdot Inc.
- Inventors: Paul H. Miller; Charles D. Stelzner
- Web page: https://patentgrep.com/patent/US4490587A

## CPC

- H01H 13/785: characterised by the material of the contacts, e.g. conductive polymers
- H01H 13/702: with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
- H01H 13/703: characterised by spacers between contact carrying layers
- H01H 2201/032: Conductive polymer; Rubber
- H01H 2209/03: elastomeric
- H01H 2209/052: elastomeric
- H01H 2209/074: elastomeric
- H01H 2211/028: Contacts in depressions of layers
- H01H 2215/006: Only mechanical function
- H01H 2215/008: Part of substrate or membrane
- H01H 2223/002: sealed
- H01H 2223/022: Adhesive
- H01H 2227/002: Layer thickness
- H01H 2227/01: Adhesive
- H01H 2229/028: Adhesive
- H01H 2231/05: Card, e.g. credit card
- H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00)

## Abstract

A switch assembly comprising a flexible face cover membrane; a flexible keyboard membrane positioned immediately below the face cover membrane and including a base portion and a plurality of raised hollow contact pad portions projecting upwardly from the base portion through openings in the face cover member; a flexible printed circuit board membrane positioned below the keyboard membrane for switching coaction with the contact pad portions of the keyboard membrane; and adhesive means bonding the membranes together into a thin, flexible sealed switch sandwich. In one embodiment of the invention, the keyboard membrane is formed of a non-conductive elastomeric material and conductive elastomeric buttons are secured to the underside of the contact pad portions of the keyboard membrane for coaction with printed circuitry on the upper surface of the circuit board membrane.

## Claims

### Claim 1

A flexible switch assembly for providing a signal for use by solid state electronic logic circuitry, said switch comprising:
A. a flexible face cover membrane having a plurality of openings therein;
B. a flexible keyboard membrane positioned immediately below the face cover membrane and including a base portion and a plurality of raised hollow contact pad portions projecting upwardly from the base portion through the respective openings in the face cover membrane;
C. a flexible printed circuit board membrane positioned below the keyboard membrane for switching coaction with said contact pad portions;
D. adhesive means bonding said membranes together into a thin, flexible, sealed switch sandwich;
E. said keyboard membrane being formed of a nonconductive ellastomeric material; and
F. a plurality of conductive elastomeric buttons secured to the underside of each contact pad portion, respectively, for coaction with printed circuitry on the upper surface of the circuit board membrane, said buttons being normally disposed in the plane of said cover membrane within the openings therein and movable out of said plane into contact with said printed circuit board membrane, each contact pad portion having a mesa configuration and connected to the base portion of the keyboard membrane by sloping walls which are configured to allow the contact pad portion to move downwardly through the opening in said face cover membrane with a toggle action to transmit a positive tactile contact signal to the operator.