introducing reinforcing material to a cavity at {HEAD ~ an angle} of less than 90° with respect to said {TAIL ~ conduit} 
introducing reinforcing material to a cavity at { HEAD ~ an angle } of less than 90 ° with respect to said { TAIL ~ conduit }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL