US Patent 7647936 Runner assembly for an umbrella frame

A runner assembly for use with a central shaft of an umbrella frame includes a tubular retaining block which is movable relative to a tubular runner in a transverse direction relative to an axis of the central shaft, and a tubular thrust member movable along the axis. An inner sleeve surface of the thrust member is configured such that, when the thrust member is pressed from a releasing position to an actuating position, the retaining block is moved from a first position to a second position to permit a retaining member disposed thereon to engage an engaging surface of the central shaft so as to keep the umbrella frame in an open state.