# US 4,400,758 A · Capacitance switch arrangement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,400,758 A - Document ID: US4400758A - Status: Granted - Kind: A - Application number: 06/278,658 - Filed: 1981-06-29 - Granted: 1983-08-23 - Earliest claimed: 1981-06-29 - Assignees: W. H. Brady Co. - Inventors: Norman J. Frame - Web page: https://patentgrep.com/patent/US4400758A ## CPC - H03K 17/975: using a capacitive movable element - H01H 13/702: with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches - H01H 2239/006: Containing a capacitive switch or usable as such - H01H 2239/01: combined with other elements on the same substrate - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - 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 capacitance-type membrane switch in which ordinarily spaced-apart contacts are positioned other than directly over an associated capacitance spacing element with an inner insulating layer and outer conductive portions. ## Claims ### Claim 1 A capacitance switch comprising a substrate, a first conductive contact carried by said substrate, a flexible sheet extending over said substrate, a second conductive contact carried by said flexible sheet and aligned with and ordinarily spaced from said first contact, a capacitance spacing element carried by one of said substrate and said flexible sheet, located other than directly under or above said contacts, said capacitance spacing element comprising an inner insulating layer and outer conductive portions, one said conductive portion being electrically connected to one said contact, and first means for connection of the other said contact and the other said conductive portion to external circuitry, whereby said flexible sheet may be flexed to vary the spacing between said contacts to increase the capacitance of said switch. ### Claim 2 (depends on 1) The switch of claim 1 further comprising a third contact carried by the other of said substrate and said flexible sheet that said capacitance spacing element is carried by, said third contact being electrically connected to second means for connection to external circuitry and being aligned with and ordinarily spaced from said conductive portion not electrically connected to said first means for connection to external circuitry, whereby said flexible sheet may be flexed to vary the spacing between said third contact and said capacitance spacing element. ### Claim 3 (depends on 2) The switch of claim 2 further comprising a fourth contact carried by the other of said substrate and said flexible sheet that said capacitance spacing element is carried by, electrically connected to third means for connection to external circuitry, aligned with and ordinarily spaced from said conductive portion not electrically connected to said first means for connection to external circuitry, and spaced from said third contact, whereby said flexible sheet may be flexed to vary the spacing between said fourth contact and said capacitance spacing element. ### Claim 4 (depends on 2) The switch of claim 2 further comprising a plurality of said capacitance spacing elements and fifth contacts associated with said plurality of capacitance spacing elements, some of said fifth contacts being aligned with and ordinarily spaced from conductive portions of said plurality of capacitance spacing elements, some of said fifth contacts being aligned in ordinarily spaced pairs and being remotely located from but electrically connected to their associated capacitance spacing elements. ### Claim 5 (depends on 4) The switch of claim 4 wherein said contacts are arranged in positions corresponding to positions of typewriter keys, said capacitance elements being aligned with rows of said typewriter key positions. ### Claim 6 (depends on 5) The switch of claim 5 wherein sixth contacts are provided and arranged in pairs in positions corresponding to positions of numerical computation keys, said sixth contacts being located remotely on said switch from said contacts having positions corresponding to said positions of typewriter keys, one said contact of each said pair being electrically connected to a conductive portion of a capacitance spacing element aligned with a corresponding typewriter row. ### Claim 7 (depends on 1) The switch of claim 1 wherein an end of said capacitance spacing element is folded over in the direction away from the sheet that carries it, and said other said conductive portion is in electrical communication with a conductor carried by the sheet that said spacing element is not carried by, whereby all conductors comprising electrical connections to external circuitry can be carried by a single sheet. ### Claim 8 (depends on 7) The switch of claim 7 wherein another end of said capacitance spacing element is folded over in the direction toward the sheet that carries it, and said one conductive portion is in electrical communication with a conductor carried by the sheet and electrically connected to said one contact.