1. IN A LOOM APPARATUS OF THE TYPE INCLUDING A SHED, A STATIONARY WEFT SUPPLY LOCATED OUTSIDE THE SHED, A LOOM MOTOR, FIRST LOOM MEANS DRIVEN BY SAID MOTOR, AND HEALD OPERATING MEANS ADAPTED TO BE DRIVEN BY SAID MOTOR IN A GIVEN TIMED RELATIONSHIP RELATIVE TO SAID FIRST LOOM MEANS; THE INVENTION WHICH COMPRISES A LOOM SPROCKET GEAR CONNECTED WITH SAID FIRST LOOM MEANS FOR SUMULTANEOUS DRIVEN MOVEMENT THEREWITH; MEANS INCLUDING A SECOND SPROCKET GEAR FOR DRIVING SAID HEALD OPERATING MEANS; ADJUSTABLE MEANS AFFORDING A CONTINUOUS AND POSITIVE MECHANICAL CONNECTION BETWEEN SAID SECOND SPROCKET GEAR AND SAID LOOM SPROCKET GEAR TO THEREBY EFFECT DRIVING OF SAID HEALD OPERATING MEANS, SAID ADJUSTABLE MEANS BEING OPERABLE TO VARY THE INSTANTANEOUS ANGULAR RELATIONSHIP OF SAID SECOND SPROCKET GEAR RELATIVE TO SAID LOOM SPROCKET GEAR; AND OPERATING MEANS FOR OPERATING SAID ADJUSTING MEANS TO ESTABLISH ONE OF TWO PREDETERMINED ANGULAR RELATIONSHIPS BETWEEN SAID LOOM SPROCKET GEAR AND SAID SECOND SPROCKET GEAR.