Patent US 3,934,236

Overlay patterns of discrete circuit elements for field-accessed, magnetic bubble propagation are driven by repetitive sequences of pulsed magnetic fields directed along axes which are parallel to consecutive overlay elements or segments with different orientations. A chevron circuit is driven by a series of reversing pairs of pulsed fields aligned alternately with the legs of the chevron elements. Two opposite parallel chevron circuits are driven in the same direction by the same sequence of pulsed fields. A broken element circuit, resembling a chevron circuit with the vertices removed, is driven in a similar manner.