adjust the acceleration or deceleration of {HEAD ~ said advance means} to drive {TAIL ~ said instantaneous gap value} g toward said nominal gap value, whereby the number of documents passing through the system per unit time may be controlled and maximized 
to drive
adjust the acceleration or deceleration of { HEAD ~ said advance means } to drive { TAIL ~ said instantaneous gap value } g toward said nominal gap value , whereby the number of documents passing through the system per unit time may be controlled and maximized
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH