Multi-stitch cam needle bar shifter for tufting machines

摘要

A tufting machine having a pattern cam needle bar shifting mechanism includes an indexing device for driving the cam intermittently so that the cam remains stationary during a portion of the needle bar cycle, that portion being at least during a portion of the time the needles are within the needle plate. A one-way ratchet clutch drive driven from an eccentric on the main shaft of the tufting machine supplies the intermittent motion to the cam in one embodiment of the invention. A positively acting brake to prevent the fly wheel effect on the pattern cam ensures a positive stopping and commencement of the stationary state.