a timing gear carried by {HEAD ~ said housing} and within said chamber and having {TAIL ~ a predetermined number} of teeth 
a timing gear carried by { HEAD ~ said housing } and within said chamber and having { TAIL ~ a predetermined number } of teeth
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH