Abstract: The invention relates to input and output circuits for multiplexing equipment, especially the kind used in telephone systems where nominally identical clocking signals have natural deviations of timing (called "plesiochronous" signals). The invention uses the "justification" principle to ensure the clock synchronization of plesiochronous digital signals. A buffer memory, with independent writing and reading capabilities, is formed of two first in-first out or "FiFo" memories connected in series. The request signal for a "justification" is made when a connection is completed between an IR (Input-Ready) output of the second FiFo memory and an input SO (Shift-Out) of the first FiFo memory, if there is an undesirable phase shift between the input and output clocking system.

Abstract: An umbrella having uniquely designed and located vents for the protection of its structural components when used in open spaces where winds of medium and high velocities are encountered. The vents comprise pivotal flaps fabricated of semi rigid material and resiliently seamed to the ribs being caused to open due to air pressure exerted against the underside of the umbrella sufficient to cause the ribs to flex in the normal manner under such conditions. The vent attachments to the ribs are located at a distance from the peak of the umbrella near the swinging connections of the ribs and struts whereby pressure on both components may be relieved at these critical points.