Designer's Corner 152

Thermoformed keyboard

Four laminates make the keyboard: A top polyester foil, spacer, circuitry layer, and back adhesive. Screen printing on the foil's rear side protects the graphics while the spacer helps determine keyboard travel and creates an air-displacement chamber during activation.

Feedback comes from a thermo-mechanical embossing procedure that forms the patented domes and optimizes each key's force-vs-travel curve. Absence of metal "clicker" domes eliminates fatigue failure and subsequent autocontact--hence the keyboard's long life.

Danny Marquenine, Velleman Switch N.V., Legen Heirweg 37, B-9890 Gavere, Belgium, FAX +32 9384 7388.

Hardy wire harnesses

EverFlex cables' Molded Woven construction aligns and separates individual wires within a flat, elastomeric mesh. Unlike bundled or ribbon-style harnesses, the mesh constrains individual wires transversely but not axially, minimizing wire tension during bending. Custom designed, they bend at prescribed points and snake around obstacles to protect wires from chafing or pinching during machine assembly or repair.

The open-weave design confers several additional benefits including improved convective cooling, lower impedance, and reduced cross talk. Depending on the application, the flat-pack configuration reduces space and weight requirements by 50% or more. With molded-in grommets or anchors and custom wire colors, the cables can also significantly reduce assembly times.

Floyd Ysbrand, Midcon Cables Co., 2500 Davis Blvd., P.O. Box 1786, Joplin, MO 64802, (417) 781-4331.