Patents by Inventor Karl-Heinz Claassen

Karl-Heinz Claassen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4442055
    Abstract: A process for the manufacture of a contact mat suitable for a keyboard or ypad is described. This contact mat is produced by the injection-moulding process and consists of a sheet-like composite body made of an electrically non-conductive two-component silicone rubber, and at least one carrier part, which is elastically deformable when pressure is applied to a key and is moulded out in the shape of a calotte. On the inside of the carrier part and in the pole region, there is a contact component which is made of an electrically highly conductive material. When the carrier part is depressed, an electrical connection is made via the contact component between the contact surfaces of a printed circuit located below the contact mat. In order to be able to manufacture the contact component in a simple manner and without waste, the contact component is made in an injection mould, wherein the entire lower mould part is at a temperature above the vulcanization temperature of the contact component.
    Type: Grant
    Filed: September 28, 1982
    Date of Patent: April 10, 1984
    Assignee: Preh Elektrofeinmechanische Werke Jakob Preh Nachf. GmbH & Co.
    Inventors: Jurgen Oelsch, Richard Volk, Karl-Heinz Claassen