Patents Assigned to Key Innovations Limited
  • Patent number: 4839474
    Abstract: A low profile switch or keypad has one or more touch buttons of circular or polygonal shape in plan formed integrally with and raised from a surrounding membrane of elastomeric material by a wall of resiliently deformable material of thickness and angle relative to the membrane so that the wall can flex under finger pressure on the or each button without deflecting the surrounding membrane. The membrane and at least the periphery of the button are relatively thick and the wall is relatively thin so that deformation during the keystroke is localized in the wall. The length of the wall is about equal to the keystroke and is relatively small compared to the width of the touch button. The junction between the wall and the membrane is located a distance greater than the keystroke above the lower surfaces of the membrane so that the wall passes overcenter during the keystroke resulting in a change in tactile sensation.
    Type: Grant
    Filed: December 10, 1987
    Date of Patent: June 13, 1989
    Assignee: Key Innovations Limited
    Inventors: Richard P. Hayes-Pankhurst, Brian D. Smith