Cantilever lock

A support bracket locking mechanism for locking a cantilever support bracket which is adapted to be mounted on a slotted standard through a plurality of aligned hook connectors. The locking mechanism includes a flexible and slidable locking member having a locking tab and an actuating tab thereon. The locking tab is interposed into the series of aligned hook connectors in a position between and equidistantly spaced from two adjacent hook connectors and is movable to a position nearer one of the two adjacent hook connectors to lock the hook connectors into the slotted standard in response to movement of the actuating tab to a locked position.