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Four Marshall Management, L.L.C.

Four Marshall Management, L.L.C. Patent applications
Patent application numberTitlePublished
20110266098Elevator Hoistway Door Closer - Elevator hoistway door closer device that increases the closing force on the door as the door approaches the door closed position. A elevator hoistway door closer includes a reel having a groove in its side that terminates in a flat edge beyond a breakover angle. The groove may have a first portion of essentially constant diameter and a second portion having a conical helix shape. The third portion includes the breakover angle and may terminate in a flat edge. There may be an elongate tensile element received by the first and second portions and the third portion defined by the breakover angle flat edge, and that has a free end for attachment to a fixed point. There may be a spring for rotating the reel and attracting the elongate tensile element by wrapping the elongate tensile element around the first and second portions of the channel and over the breakover angle and flat edge of the third portion.11-03-2011