A multilayer membrane switch structure is disclosed wherein the flexible membrane is fixedly attached to a support frame member by a pattern of adhesive regions, the regions positioned in locations corresponding to the switch locations of the structure. The adhesive engagement of the bottom surface of the membrane structure stabilizes the bottom electrical contact and, at the same time, leaves open regions between the adhesive regions which will accommodate air which is exhausted from the switch cavity through a hole formed in the bottom layer of the multilayered switch structure into communication with the open regions between the adhesive regions. Thus, the open regions act to exhaust the air in a switch cavity when the switch is activated.
|US3860771||Oct 29, 1973||Jan 1, 1975||FIG.ZO|
|US4046975||Sep 22, 1975||Sep 6, 1977||Chomerics, Inc.||Keyboard switch assembly having internal gas passages preformed in spacer member|
|US4118611||Aug 30, 1977||Oct 3, 1978||International Business Machines Corporation||Buckling spring torsional snap actuator|
|US4362911||Sep 17, 1980||Dec 7, 1982||NCR Corporation||Membrane keyboard switch assembly having selectable tactile properties|
|US4365130||Dec 28, 1981||Dec 21, 1982||North American Philips Corporation||Vented membrane switch with contaminant scavenger|
|US4373122||Oct 16, 1981||Feb 8, 1983||W. H. Brady Co.||Capacitance switch|
|US4375018||Jun 16, 1980||Feb 22, 1983||Sheldahl, Inc.||Membrane switch having adhesive label as edge seal|
|US4415780||May 28, 1981||Nov 15, 1983||Rogers Corporation||Keyboard with edge vent|
|US4485279||Sep 30, 1982||Nov 27, 1984||Alps Electric Co., Ltd.||Keyboard switch|
|US4489227||Jan 11, 1984||Dec 18, 1984||Sheldahl, Inc.||Back lighted, full travel push button membrane keyboard|
|USRE31332||Jun 8, 1981||Aug 2, 1983||Oak Industries Inc.||Membrane switch with means for preventing contamination of the interior thereof|
|US4701579||May 28, 1986||Oct 20, 1987||Brother Kogyo Kabushiki Kaisha||Data entry keyboard|
|US4760217||Feb 3, 1987||Jul 26, 1988||Brother Kogyo Kabushiki Kaisha||Keyboard having lower casing with integral upraised portion for supporting PC board, and key switch having air vent in PC board|
|US4876415||Mar 31, 1988||Oct 24, 1989||Honeywell, Inc.||Low cost keyboard with key tops defining surface of curved profile|
|US5001307||Aug 10, 1989||Mar 19, 1991||Mannesmann Kienzle GmbH||Keyboard|
|US5228561||Apr 1, 1991||Jul 20, 1993||Hewlett-Packard Company||Long traveling button switch with enhanced user feedback|
|US5708562||Jun 18, 1996||Jan 13, 1998||International Business Machines Corporation||Portable computer and a keyboard therefor|
|US5929401||Feb 19, 1998||Jul 27, 1999||U.S. Philips Corporation||Curved keyboard keypad and contact structure|
|US5969644||Nov 5, 1996||Oct 19, 1999||Alps Electric Co., Ltd.||Keyboard|
|US5986228||Feb 12, 1999||Nov 16, 1999||Matsushita Electric Industrial Co., Ltd.||Movable contact unit for panel switch and panel switch using the same|
|US6265677||Jul 2, 1999||Jul 24, 2001||Acer Peripherals, Inc.||Keyboard assembly including circuit membrane switch array|
|US6320147||Dec 28, 1999||Nov 20, 2001||Delphi Technologies, Inc.||Dual contact membrane horn switch assembly|
|US6563069||Jun 7, 2001||May 13, 2003||Delphi Technologies, Inc.||Horn switch|
|US6634090||Jul 11, 2001||Oct 21, 2003||Matsushita Electric Industrial Co., Ltd.||Method of production of series of a tactile contact units and tactile contact unit, and series of tactile contact units and a tactile contact unit produced by using the same method|
|US6781077||Dec 14, 2000||Aug 24, 2004||Think Outside, Inc.||Keyswitch and actuator structure|
|US7657994||Oct 19, 2005||Feb 9, 2010||Delphi Technologies, Inc.||Method for installing a switch pad|
|USRE32977||Jul 9, 1987||Jul 4, 1989||Brother Kogyo Kabushiki Kaisha||Key-holding structure of keyboard with curved operating surface of keys|
1. A keyboard comprising
- a matrix multilayer switch comprising:
- a first flexible sheet with a first and second surface with electrical circuit paths and plural switch contacts deposited on said first surface thereof;
- a second flexible sheet with electrical circuit paths and plural switch contacts deposited on a first surface thereof;
- a spacer sheet with at least an aperture formed therein, positioned between said first and second flexible sheets and with said aperture aligned with portions of said electrical circuits on each of said sheets to form a passage through which said circuit on said second flexible sheet may contact said circuit on said first flexible sheet and with said first surfaces in face-to-face relation with faces of said spacer,
- at least a zone of adhesive interposed between said spacer and each of said flexible sheets to form a multilayer structure with each of said spacer and sheets restricted from movement with respect to each other in the plane of said spacer sheet; and
- a rigid support plate and adhesive engaging a first surface thereof, said multilayer switch adhesively attached to said rigid support plate, said adhesive engaging said rigid support plate comprising at least a spot of adhesive localized at and positioned between said support plate and said multilayer switch and adjacent said each of said switch contacts and engaging said second surface of said first flexible sheet, thereby stabilizing said electrical circuit path on said first flexible sheet, the substantial portion of the remainder of said second surface remaining without adhesive, and
- an actuator means aligned with and operable manually to actuate said multilayer switch, comprising a keybutton and a switch engaging member operable upon displacement of said keybutton to deflect switch contacts on said second sheet into contact with said switch contacts on said first sheet.
2. The keyboard of claim 1 wherein said rigid support plate is curved to a radius approximately the curve defined by the fingers of an operator as said fingers are extended to engage said keybuttons and where said plural switch contacts on said first sheet are fixedly positioned relative to said plate by said spots of adhesive between said plate an said first sheet.
3. The membrane switch structure of claim 2 wherein said spot of adhesive is substantially circular and is positioned between and aligned with said switch contacts and said support means.
4. The keyboard of claim 3 wherein said first flexible sheet has formed therein a hole extending from said first side to said second side thereof and communicating with said aperture and an area between said first flexible sheet and said rigid support plate where no adhesive exists.
5. The keyboard of claim 4 wherein said adhesive circular pattern comprises a sector, which has no adhesive, corresponding in location to the position of said hole, thereby creating a communication between said hole and said region of no adhesive between said first flexible sheet and said rigid support plate.
6. The keyboard of claim 2 wherein said multilayer structure is further adhesively attached to said support plate by adhesive deposited in a substantially continuous band adjacent three edges of said first flexible sheet and intermediate said sheet and said rigid support plate.
7. The keyboard of claim 3 wherein said multilayer structure is further adhesively attached to said rigid support plate by adhesive deposited in a substantially continuous band adjacent three edges of said first flexible sheet and intermediate said first sheet and said rigid support plate.
8. The keyboard of claim 4 further comprising additional regions of adhesive extending generally outward from said region of adhesive, thereby fixedly adhering said first flexible sheet to said rigid support plate in regions where objects may engage said membrane switch without causing one of said switch contacts to contact the other of said switch contacts.
9. The keyboard of claim 1 further comprising a frame for supporting said actuator means and said frame attached through said membrane switch and to said rigid support plate.
10. The keyboard of claim 9 wherein said frame further comprises tenons extending through said rigid support plate and deformed to prevent removal of said frame from said plate.
11. A keyboard comprising:
- a membrane switch structure having a plurality of switch positions having a laminate of at least three layers and a rigid support member, with said member selectively adhered to said laminate with spots of adhesive positioned between said member and said laminate in areas corresponding to each of said switch positions, said middle layer of said laminate comprising a hole formed at the position corresponding to each of said switch positions, thereby defining in cooperation with the other two layers a cavity, and air exhausting means communicating between said cavity and the portion of space between said laminate and said support member having no adhesive adhering the laminate and said support member.
12. The keyboard of claim 11 wherein said spot of adhesive is substantially circular.
13. The keyboard of claim 12 wherein said laminate is further adhesively attached to said support member by adhesive deposited in a substantially continuous strip adjacent three edges of said laminate and intermediate said laminate and said support member.