in the jersey knitting stage the intermediate jacks 4 gradually tilt to the tuck and welting positions producing the corresponding paths the cam body 18 comprises a support holding a number of blocks in the known form in which there are housed sets of cams 19a 19b and 19c on the one hand and further cams 20a 20b 20c and 20d on the other hand forming respective columns with the corresponding holding screws 21 and nuts 22 which with the corresponding grooves define the channels for the butts 15 16 and 17 as far as the grooves for the butts 15 and 16 of the intermediate jacks 4 are concerned the distance d between the lower edges of said butts is greater than the distance d between the respective grooves in this way fig3 illustrates the knitting operation comprising the participation of both butts 15 and 16 of an intermediate jack 4 plus the butt 17 of a needle 5 butt 15 being the operative one wherein the selector jack 3 has been urged to the knit position by spring 14 i e is in the vertical position as shown in fig1 and butts 15 engage cams 19c in view of this said butt 15 runs up the cam 19c to the peak and then down the other side whereby butt 16 follows a similar path but spaced apart from cam 19b while butt 17 of the needle 5 follows the same upward path pushed by the intermediate jack 4 to the maximum rise position during this part of the movement the cam 19a acts as a countercam engaging the butt 17 and limiting the upward movement of the needle 5 thereby preventing the needle from experiencing excessive upward movement the drawdown movement of the needle.