cams lifting triangles or selection keys 37 38 39 and 40 can be brought into action or taken out of action by means of magnets for the purpose of needle selection the remaining cam units shown by vertical hatching are stationary and are not shiftable the central longitudinal axis of the system of cam units is indicated at m in the embodiment of cam system shown in fig5 to 13 one can knit in one row of knitting either selected stitches or tuck loops or knit with the three path technique with selectively chosen needles and with different size stitches and tuck loops furthermore with this cam system any transfer can be made in both directions of traverse of the carriage to the rear needle bed or to the forward needle bed or to both needle beds at the same time fig5 shows this preferred first embodiment of cam system with the most important reference numbers present fig6 shows the shifting of the cam system for a carriage movement from right to left and for a needle pass and jack pass for the production of equal size stitches the selection key 38 and the cam unit 29 are shifted into action the needles and jacks occupy their basic positions the second needle butt 9 remains sunk in the needle bed 1 in other words outside the relevant cam zone the needle sinker 34 is brought to the withdrawal position and the needle sinker 35 is set manually or by.