To this end two drive rings concentric with {TAIL ~ the axis} of rotation of the program carrier are provided, of which one revolves at {HEAD ~ a speed} of one revolution per day and the other at one revolution per week 
To this end two drive rings concentric with { TAIL ~ the axis } of rotation of the program carrier are provided , of which one revolves at { HEAD ~ a speed } of one revolution per day and the other at one revolution per week
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH