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