Circular hosiery machine and the like, having simplified program control means

A circular knitting machine comprising a needle cylinder, means defining a control cam shell, means defining a program cam drum, said cam shell and program drum being co-axial with the needle cylinder, pawl means for advancing said drum, means for causing the drum to advance selectively through angular movements of short or long-pitch, said advancing means comprising means defining an array of seats on the drum, removable pin means located in selected ones of the seats, and control means cooperating with the pin means and operative to control the pawl means in dependence on the arrangment of the pin means so as to effect short or long-pitch advance of the drum, two ratchet wheels rotatable with the drum, one of said ratchet wheels having small-pitch teeth, and the other of said ratchet wheels having long-pitch teeth, said pawl means comprising first and second pawls each associated with a respective one of the two ratchet wheels, said control means being operative to actuate a selected one of the two pawls in accordance with the arrangement of the pin means, a manual control for actuating that one of the pawls which is associated with the ratchet wheel having long-pitch teeth to cause a rapid advancement of the drum to a zero-setting position, means for maintaining said advancement until said zerosetting position has been reached, a cam rotatable with the needle cylinder, means linking the cam to that one of the pawls which is associated with the ratchet wheel having long-pitch teeth such that the pawl is reciprocated by rotation of the cam, said linking means being rendered selectively operative and inoperative by the action of said control means and of said manual control, and means for changing the speed of needle cylinder rotation, such that during the long-pitch advancements of the drum, the cylinder rotates at a reduced speed.