US Patent 4,579,149, granted 1 April 1986 to Franz X. Huemer of Vienna, for a circular loom whose shaft-driving mechanism uses two-armed control levers. The levers connect a revolving plate cam to belt-type partial healds, which move the inner and outer yarn guiding eyes up and down to form a travelling shed for tubular fabric. The patent gives the abstract, background, description of the drawings (Figs. 1-5), alternative lever-to-belt anchorages and five claims. It has three sheets of mechanical drawings.