Patent ID: 9134600
Filing Date: 2015-09-15
Classification: G03B

Abstract:
1. A large screen display drive mechanism comprising: a frame including a stationary truss having a truss axis and bearings, said truss having a plurality of elongated members extending parallel and horizontal to the truss axis, said truss further having cross members attached to and spacing apart said members, said elongated members and cross members defining a top, opposite sides, and an open bottom forming a drum enclosure, said truss having opposite ends with said bearings mounted to said opposite ends; a drum located and extending between said elongated members and cross members and rotatable within said stationary truss for wrapping a large screen display thereon with the drum rotatably mounted to said truss to extend said display from said truss only through said open bottom and to retract said display within said truss, said drum having a first end and a second end and having length therebetween, said elongated members and cross members of said truss surround and completely enclose said drum within said drum enclosure of said truss along said length of said drum while said elongated members and said cross members extend across said top and said opposite sides protecting said drum from impact by external objects as the truss, display and drum are lifted and lowered in place; an axle extending through said bearings applying weight of the large screen display directed via said axle to said bearings and said truss, said axle having an longitudinal extending axis parallel to said truss axis, said axle mounted to said drum and having a main axle portion extending between said first end and said second end with said axle having a first end portion extending outwardly of said first end of the drum and rotating in unison about said axis with said main axle portion; a first drum sprocket fixedly mounted to said first end of said drum; a cable assembly having an interior segment located within said drum between said first end and said second end and having an exterior segment located outwardly of said first end, said interior segment connectable to a large screen display wrappable on said drum, said cable assembly extending through said first end of the drum and said first drum sprocket and then spiraling around said first end portion of said longitudinal extending axis of said axle outwardly of said first end of said drum, said cable assembly having an outer end that is stationary while said drum and interior segment of said cable assembly within said drum rotate in unison together while limiting relative motion of said interior segment of said cable relative to said drum; a first motor having a first drive sprocket thereon to drive said first drum sprocket and rotate said drum by applying driving force to said drum outwardly of said axle limiting axle twisting and allowing said exterior segment of said cable assembly to wind and unwind on said first end portion outwardly of said drum with said interior segment of said cable assembly rotating with and within said drum; and wherein: said axle has a second end portion extending outwardly of said second end of the drum, and further comprising: a second drum sprocket fixedly mounted to said second end of said drum; and, a second motor having a second drive sprocket thereon to drive said second drum sprocket and rotate said drum by applying driving force to said drum outwardly of said axle limiting axle twisting and allowing said cable assembly to wind and unwind on said second end portion.