Apparatus for carrying out automatic repeat change in embroidery machines

Claim 1

IN AN EMBROIDERY APPARATUS WHEREIN AN ELONGATED NEEDLE BAR IS PROVIDED WITH AN ARRAY OF NEEDLES EXTENDING IN A DIRECTION GENERALLY TRANSVERSE THERETO FOR ENGAGEMENT WITH A FABRIC EXTENDING GENERALLY PARALLEL TO SAID NEEDLE BAR AND PERPENDICULARLY TO SAID NEEDLES, THE IMPROVEMENT WHICH COMPRISES: A PLURALITY OF NEEDLE CARRIAGES, EACH CARRYING A RESPECTIVE ONE OF SAID NEEDLES AND PROVIDED WITH A RACK, DISPLACEABLY MOUNTED ON SAID BAR FOR INDIVIDUAL MOVEMENT IN SAID DIRECTION BETWEEN AN EXTENDED POSITION WHEREIN CORRESPONDING NEEDLES ARE ENGAGEABLE WITH SAID FABRIC AND A RETRACTED POSITION WHEREIN CORRESPONDING NEEDLES ARE WITHDRAWN FROM ENGAGEMENT WITH SAID FABRIC; DRIVE MEANS ON SAID BAR FOR DISPLACING SAID NEEDLE CARRIAGES BETWEEN SAID POSITIONS; AND ACTUATING MEANS OPERABLE FOR COUPLING SELECTED ONES OF SAID CARRIAGES WITH SAID DRIVE MEANS FOR DISPLACEMENT RELATIVE TO SAID BAR INTO ONE OF SAID POSITIONS AND FOR TEMPORARILY LOCKING THE REMAINDER OF SAID CARRIAGES AGAINST DISPLACEMENT RELATIVE TO SAID BAR, SAID DRIVE MEANS INCLUDING A DRIVE RACK LONGITUDINALLY SHIFTABLE ALONG SAID BAR AND A RESPECTIVE PINION ASSIGNED TO EACH OF SAID CARRIAGES AND SHIFTABLE ON SAID BAR BETWEEN A FIRST POSITION WHEREIN THE RESPECTIVE RACK OF EACH CARRIAGE IS COUPLED WITH SAID DRIVE RACK AND A SECOND POSITION WHEREIN SAID RESPECTIVE RACK IS DECOUPLED FROM SAID DRIVE RACK, SAID ACTUATING MEANS INCLUDING CAM MEANS FOR SELECTIVELY SHIFTING SAID PINIONS.