Abstract: A device that converts an existing power tool to apply a rotational force to a spring of a rollup or overhead door counterbalancing mechanism. The device has a rotatable driven member mounted in a casting that carries a power transmitting structure. The casting and the driven member have slots with an open end for accommodating the shaft of the counterbalancing mechanism. A removable novel coupling structure inserts into the driven member and connects the driven member to the winding cone of a spring so that rotation of the driven member will apply rotational force to the spring. The casting with the driven member is connected to the body of an existing power tool in place of the original tool head. A motor in the existing power tool body is connected to the power transmitting structure in the casting to rotate the driven member.

Abstract: An apparatus for the detection of any intruder passing through an electronic fence is disclosed. The electronic fence is formed by a millimeter wave radar positioned at one end of the fence and a plurality of reflectors placed along the floor of the fence as well as on a structure at its far end. The fence is formed of a plurality of electromagnetic beams traversing between the radar antenna or antennas and each of the reflectors. A sufficient number of beams inhabit the fence volume to make traversing the fence by an intruder without detection essentially impossible. The radar reflection from the intruder's person is used to report the location of an intruder attempting to traverse the electronic fence near the radar end and is the secondary means of detection at greater ranges where breaking of one or more electromagnetic beams constitutes the primary means of detection.