作者: George J. Steinhagen
DOI:
关键词: Beam (nautical) 、 Engineering 、 Hook 、 Vertical axis 、 Structural engineering 、 Fixed Beam 、 Windlass 、 Roof 、 Winch 、 Pulley
摘要: A portable roof winch comprising a collapsible frame that is adjustable to accommodate the slant of roof, an extensible beam consisting two telescoping parts one which pivotally mounted on vertical axis and other part being moveable with respect pivot having manually operable thereon at location adjacent spaced from free end part, together seat for operator beyond winch. cable taken up winch, extends along passed over pulley fixed part. load engaging hook attached this cable.