Multi-stitch cam needle bar shifter for tufting machines

In a tufting machine having a reciprocating needle bar carrying a plurality of needles spaced transversely across the machine and adapted to penetrate a base material moving longitudinally across a support plate thereof to insert a plurality of stitches upon each penetration of the base material, mounting means for mounting said needle bar for transverse movement relatively to the base material, a rotatably mounted cam having stitch pattern information for directing the movement of the needle bar, follower means responsive to the stitch pattern information on said cam, means connecting said follower means to said needle bar for selectively shifting said needle bar transversely in accordance with the stitch pattern information on said cam, and cam drive means for rotatably driving said cam, said cam drive means comprising an index drive having input means continuously driveable through a repetitive cycle and output means driven by the input means during only an index portion of the cycle of the input means and being stationary during the remainder of the cycle of the input means, means for driving said input means in time relationship with the reciprocation of the needle bar such that said input means and said needle bar have a common cycle, and means operatively connecting said output means to said cam for rotatably driving said cam intermittently to stop the rotation of said cam at least during a portion of the time the needles are within the base material.