US Patent 7015872 Mast assembly

An antenna installation having a tower including supporting a mast supported adjacent its upper end and in turn being supported adjacent its lower end by a first hinge mechanism for pivotal movement about a first horizontally disposed hinge axis between a generally horizontally disposed lowered and vertically upstanding use positions; an antenna including a boom mounted on said mast and a plurality of antenna elements mounted on said boom to lie within plane disposed generally normal to said mast when in upstanding use position; and a hinge mechanism for supporting the antenna for pivotal movement about a second generally horizontally disposed hinge axis adopted to be disposed parallel to the first hinge axis and including gravity responsive latch means for controlling against pivotal movement of the antenna relative to the mast.