Patents Assigned to Sandstone, Inc.
  • Patent number: 4293778
    Abstract: A partially conductive security screen arrangement for use with an intrusion alarm system designed to operate in a normally closed sensing circuit condition and to produce a warning signal when the sensing circuit is broken, which arrangement includes conductive means overlying and bonded to a mesh screen positionable to cover an opening in a building. The conductive means is connectible at its two ends to the sensing circuit in a series relationship with the remainder of that circuit. The conductive means is positioned on the screen in a configuration preventing passage of a human being through the screen unless the conductive means is severed. Passage of a human being through the opening while the screen is in position to cover the opening therefore breaks the sensing circuit to produce a warning signal.
    Type: Grant
    Filed: February 12, 1979
    Date of Patent: October 6, 1981
    Assignee: Sandstone, Inc.
    Inventor: William H. Williams
  • Patent number: 4234875
    Abstract: A security panel arrangement for use with an intrusion alarm system designed to monitor the continuity of a normally continuous signal conductive path and to produce a warning signal when the signal conductive path is broken, which arrangement includes a cellular panel forming a series of parallel elongated passages through which extends at least one means for conducting a signal. The cellular panel is attached to a surface portion of a structure to be secured, and the means for conducting a signal is connected at its two ends to the alarm system in a continuity monitoring relationship therewith. Passage of a human being through the surface portion breaks the continuity of the means for conducting a signal and causes the alarm system to produce the warning signal.
    Type: Grant
    Filed: March 6, 1978
    Date of Patent: November 18, 1980
    Assignee: Sandstone, Inc.
    Inventor: William H. Williams