The head is shaped to define a channel for receiving {HEAD ~ an exposed margin} or flange of {TAIL ~ a hinge mount} to rigidly engage the hinge 
The head is shaped to define a channel for receiving { HEAD ~ an exposed margin } or flange of { TAIL ~ a hinge mount } to rigidly engage the hinge
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH