Transfer machine control

Claim 1

In a transfer machine which is disposed to load parts during a succession of part reception periods, wherein the transfer machine operates in alternating work unit and part transfer cycles to selectively machine loaded parts, and wherein different work units of the transfer machine require different operating times to complete their respective work tasks, apparatus responsive to loading of and failure to load parts for adjusting the length of a work unit cycle to the longest operating time of the work units at which parts are actually present during the work unit cycle, said apparatus comprising: a shift register providing positions for storing discrete digital data bits, each of said bit storage positions uniquely corresponding to one of said work units and being arranged in a storage position sequence so that the bit storage position at a particular location in said storage position sequence corresponds to the work unit which is at the particular location in the work unit sequence of said transfer machine; means for entering a digital bit of a first logic level into said shift register when a part is loaded into said transfer machine during one of said part reception periods, and for entering a digital bit of a second logic level into said shift register when a part is not loaded into said transfer machine during one of said part reception periods; means for advancing each of the digital bits contained in said shift register by one bit storage position in said storage position sequence in response to a part transfer cycle, a transfer mechanism of said transfer machine advancing each of said loaded parts by one work unit in said work unit sequence during a part transfer cycle; means responsive to the contents of said shift register after a given one of said part transfer cycles for activating given work units to perform their specified work tasks if a digital bit of a first logic level is contained in the bit storage positions corresponding to said given work units, and for preventing activation of said given work units of a digital bit of a second logic level is contained in the bit storage positions corresponding to said given work units; means responsive to operation of said activated work units for generating a signal at the completion of all of the work tasks of said activated work units; and means responsive to said signal and to the contents of said shift register for commencing another one of said part transfer cycles upon the simultaneous occurrence of a first condition and a second condition, said first condition occurring when said signal is generated and said second condition occurring when each of the work units which is not activated after said given part transfer cycle corresponds to a bit storage position of said shift register which contains a digital bit of said second logic level.