Patents by Inventor Stephen D. Marks

Stephen D. Marks 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: 4866423
    Abstract: A proximity alarm (2) is used to protect overhead sprinkler heads (4) from damage by signaling when an object, typically carried by a forklift, comes too close to the sprinkler head. The alarm includes a signal circuit (24) mounted within a housing (22), a mounting clamp (10) and an arm (20) connecting the mounting clamp and the housing. The clamp secures the alarm to the sprinkler head adjacent the downwardly extending water pipe (8). The signal circuit includes a signal element (30), such as a horn, and a switch (26) for actuating the signal element. The switch is operated by a trigger (32) which extends downwardly from the housing. The trigger includes a portion (38, 44) positioned to contact an object coming close to the sprinkler head. Thus, when a forklift driver is lifting an object and the object contacts the trigger, the trigger actuates the switch causing the signal element to provide a signal, typically an audible alarm, warning the operator to halt movement of the load.
    Type: Grant
    Filed: May 3, 1988
    Date of Patent: September 12, 1989
    Assignee: Tandy Corporation
    Inventors: Howard B. Anderson, II, Stephen D. Marks, Randall W. Cook