Patents by Inventor M. H. Wu

M. H. Wu 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).

  • Pencil sharpener with acoustical and lamplight indicating effect
    Patent number: 5161587
    Abstract: The present invention is directed to a pencil sharpener that incorporates a conductive sharpening blade element for sharpening the pencil wherein the blade element is positioned along an inner wall surface of a bore hole so as to contact an outer surface of the pencil. A conductive leaf spring opposingly positioned with the blade element contacts a nib of a pencil when the pencil is sharpened by the blade element, whereby the leaf spring forms an electrical contact with the blade element through the nib of the pencil. An integrated circuit sound device for producing an audible signal is operatively connected with the blade element and leaf spring so as to generate warning signals through an indicating lamp and a buzzer.
    Type: Grant
    Filed: April 22, 1991
    Date of Patent: November 10, 1992
    Inventor: M. H. Wu