Patents by Inventor Keith A Hoffman

Keith A Hoffman 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: 7063398
    Abstract: Interlocks for file cabinets that prevent more than one drawer from being opened at a given time include an elongated, flexible member, such as a cable, which is changeable from a high slack condition to a low slack condition when one of a number of associated drawers is opened. In the low slack condition, the interlocks prevent their associated drawers that are closed from being opened. In the high slack condition, which exists when the drawers are closed, the interlocks allow their associated drawers to be opened. The interlocks may be used in conjunction with a lock that selectively changes the cable from a high slack condition to a low slack condition and vice versa. The interlocks may be constructed to exert a force on the cable that is a small fraction of the pulling force exerted on a locked drawer.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: June 20, 2006
    Inventor: Keith A Hoffman