the main shaft shaft 245 of fig1 cam 358 has four protrusions 360 thus during each work cycle there is provided a reciprocating overlap movement of one needle space i e 1u slider 356 will be urged against cam 358 by the same spring forces described in connection with fig1 there exists another possibility in that the overlap displacement control arrangement is activated either by the above illustrated control cam or control chain in either case the patterning caused by the overlap displacement is limited to the instructions carried by the appropriately chosen control cam or chain however in most cases this has been found adequate it is advantageous to provide support surface 333 as the angled face surface of slider 356 which is angularly displaceable with respect to the drive displacement direction of the overlap displacement control arrangement such a control arrangement may be added to an already constructed summation drive in an arrangement such as the foregoing the overlap displacement can be in the same direction reversal occurring preferably during underlap it is further advantageous if for the maintainence of the direction of the overlap displacement direction in sequential working cycles the overlap displacement setting arrangement 342 is simultaneously activatable with the underlap displacement control arrangement 336 341 this permits the overlap displacement control arrangement 342 to return to the starting position it held in the previous work cycle in this latter control.