1. IN A ZIGZAG SEWING MACHINE HAVING A FRAME, A NEEDLE BAR, MEANS FOR MOUNTING SAID NEEDLE BAR IN SAID FRAME FOR ENDWISE RECIPROCATION AND FOR LATERAL VIBRATION, AND MEANS FOR IMPARTING LATERAL VIBRATION TO SAID NEEDLE BAR COMPRISING A BRACKET, A PIVOT ELEMENT PIVOTALLY MOUNTING SAID BRACKET IN SAID FRAME, AN OSCILLATING ELEMENT, MEANS FOR PIVOTALLY MOUNTING SAID OSCILLATING ELEMENT ON SAID BRACKET ON A PIVOT AXIS PARALLEL TO AND SPACED FROM THE PIVOT AXIS OF SAID BRACKET, A PITMAN, MEANS PIVOTALLY CONNECTING SAID PITMAN TO SAID NEEDLE BAR, MEANS ADJUSTABLY CONNECTING SAID PITMAN TO SAID OSCILLATING ELEMENT FOR ADJUSTMENT OUTWARDLY RELATIVELY TO THE PIVOT AXIS OF SAID OSCILLATING ELEMENT, AND MEANS FOR IMPARTING OSCILLATION TO SAID OSCILLATING ELEMENT COMPRISING A ROTARY CAM JOURNALED IN SAID FRAME, A CAM FOLLOWER SLIDINGLY PIVOTED ON SAID PIVOT ELEMENT AND OPERATIVELY ENGAGING SAID CAM, AND MEANS PIVOTALLY INTERCONNECTING SAID CAM FOLLOWER AND SAID OSCILLATING ELEMENT AT A POINT SPACED FROM THE PIVOT AXIS OF SAID OSCILLATING ELEMENT FOR PIVOTALLY SECURING SAID CAM FOLLOWER AND SAID OSCILLATING ELEMENT TOGETHER AT SAID POINT FOR UNITARY OSCILLATION ABOUT THE AXIS OF SAID OSCILLATING ELEMENT.