Key Tronic Corporation

George P English

Stephen S Damitio

Joseph A Benefield

Theodore D Clark

Nathan Batson

A computer keyboard 10 having a plurality of keys 18 at desired locations being supported above a support plate 20 having a plurality of apertures 22 at the desired locations. A membrane keyswitch assembly 24 is mounted on the support plate 20 having keyswitches at each desired location. The keys have key plungers 28 that move up and down in the support plate apertures 22. An elastomeric dome sheet 46 is mounted over the membrane keyswitch assembly 24 with individual elastomeric dome return springs for biasing the keys 18 to their up position. An air chamber 52 is formed beneath the support plate 20 extending between the desired key locations. An air-impervious elastomeric membrane 60 is sandwiched between the air chamber 52 and the support plate 20 forming a flexible upper wall that receives and engages the key plungers 28. The membrane 60 has individual pedestal portions at the key locations for engaging the plungers 28. A manually adjustable air supply is connected to the air chamber 52 to adjust the air pressure and thereby adjust the force required to actuate a key.

Computer keyboard with adjustable force keystroke feature using air

A computer keyboard with multiple rows of cantilevered keys which are flexibly attached to first common mounting strips. The keyboard also has multiple rows of cantilevered sub-members flexibly attached to second common mounting strips, with the sub-members being aligned beneath associated keys. The cantilevered sub-members are in sliding contact with their associated cantilevered keys and induce a tactile 'break over' sensation as the associated cantilevered keys are depressed. Each sub-member is designed to actuate a switch contact as the cantilevered key is depressed, whereby the computer keyboard can be constructed without a dome sheet.

Computer keyboard with cantilever switch and actuator design

A computer keyboard has multiple rows of cantilevered keys which are flexibly attached to common mounting strips. The rows of cantilevered keys are arranged to partially overlap adjacent rows such that the keys in one row actuate switch contacts aligned beneath mounting strips in the adjacent row. An interface between the switch contact membrane and a printed circuit board, and employing a portion of the dome sheet as supporting legs for the keyboard, are also described.

Computer keyboard with integral dome sheet and support pegs

Computer keyboard with cantilever switch design and improved PCB/switch

A computer keyboard according to a preferred construction has multiple non-conductive keys and at least one conductive key mounted in a keyboard housing. The conductive key includes a molded plastic key body having conductive material embedded therein. Conductive plugs are electrically coupled and mounted to the conductive key body. An electrostatic discharge pad is provided on a switch assembly positioned beneath the keys of the keyboard. The discharge pad is coupled to ground through a path resistor. When the conductive key body is depressed to an activated position, the plugs engage the electrostatic discharge pads so that electrostatic charges of the user progressively dissipate to ground through the key body, plug, discharge pad, and path resistor. At least one of the path resistor or the plug has a resistance greater than the resistance of the conductive key body. In this manner, electrostatic charge is routinely dissipated from a computer user while insuring that the user is not shocked when he/she initially touches and operates the conductive key.

Computer keyboard with electrostatic discharge feature

A computer keyboard employs a single monoblock structure to both support the keys and to define the aesthetic enclosure. The monoblock has multiple key supports into which key bodies are slidably mounted. The keyboard includes a switch membrane disposed on top of the monoblock and a dome sheet positioned on top of the switch membrane beneath the key bodies. The dome sheet has multiple resilient domes with openings formed therein to provide access for the key bodies to corresponding key supports. The domes support the key bodies and provide the 'spring-like' feel during operation of the computer keys. The switch membrane has annular switch contacts positioned about the monoblock key supports beneath the domes. As one of the key bodies is depressed, the associated dome buckles and actuates the annular switch contact. The computer keyboard is low cost due to having only one structural component and is quiet due to the position of the rubber or elastomer dome sheet beneath the key bodies.

Membrane computer keyboard and improved key structure

As a preferred embodiment, a computer keyboard dome sheet is illustrated in the figures showing a extruded sheet 30 with an elongated body 32 with parallel extruded ridges 44 corresponding to the keyboard rows 16a-16f. Apertures or cutouts are formed in the ridges 46 at desired intervals between the key positions to form individual ridge domes 48 having parallel front and rear walls 54 and 56 that are collapsible to bring a switch actuating keel 66, 92 into engagement with the switch structure to actuate an electrical switch to indicate that the key switch has been depressed.

Computer keyboard with flexible dome switch layer

A dome sheet molded integrally from elastomeric rubber or plastic material is divided into two or more planar sheet sections, each containing a plurality of raised domes used in keyboard actuation. The adjacent sections are integrally joined by a hinged web having walls extending outward from the plane of the sheet. The web permits translational and angular movement of the adjacent sheet sections as required to properly position them between mating keyboard parts during keyboard assembly. This assures more accurate alignment between keyswitch actuators and keyboard switching elements associated with the individual domes about the dome sheet.

Expansion joint for keyboard dome sheets

A connector clamp for attaching conductive surface pads on a flexible sheet to a printed wiring board having complementary conductive surface pads is bent from an elongated precut pattern. The resulting clamp member includes a series of transverse fingers along one leg of a U-shaped cross-sectional configuration. The fingers are opposed by a continuous leg joined to them by a continuous central base that completes the U-shaped cross-sectional configuration. The internal width across the central base exceeds the combined thickness of the sheet and board secured by the clamp. It exerts clamping force along a line extending across both clamp legs to assure both mechanical and electrical connection between the joined elements.

Connector clamp for attaching flat electrical conductor leads to printed

A keyswitch operator includes a supporting bearing block and axially movable keytop and plunger. A cylindrical plunger is slidably guided between alternating flat and conical surfaces about a through bore in the bearing block. The flat surfaces provide constant bearing guides along multiple axial lines angularly spaced about the plunger. The conical surfaces provide draft to facilitate removal of a mold after forming of the through bore. Both 'quiet tactile' and 'click tactile' modes of operation are available when utilizing the keyswitch operator in conjunction with a yieldable dome overlying a membrane switch assembly. 'Click tactile' operation requires the addition of a spring-biased piston to physically engage the underlying switch assembly when the plunger has been depressed.

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Coeur d'Alene, ID, United States of America

George P English