Patents by Inventor Thomas Hänisch

Thomas Hänisch 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).

  • Piezoelectric acoustic alarm
    Patent number: 6541894
    Abstract: In a piezoelectric acoustic alarm piezoelements (2a, 2b) each excited by a square-wave voltage are arranged opposite each other in a resonance cavity (1) and each oscillate in opposing directions. The two square-wave voltages (Va, Vb) controlled by a microprocessor (8) are phase displaced by a square-wave pulse length and are positive or negative. A piezo-sound source designed and excited in this way is characterised by a high sound volume with low current consumption and small size.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: April 1, 2003
    Assignee: MSA Auer GmbH
    Inventors: Thomas Hänisch, Peter Frank