Although flanges 27 can be rectangular as shown in a preferred case, they may be alternatively of any cross sectional geometry that would prevent rotation thereof with {HEAD ~ respect} to {TAIL ~ trough} 28, in which instance corresponding holes 29 would be of a matching receiving shape 
to
Although flanges 27 can be rectangular as shown in a preferred case , they may be alternatively of any cross sectional geometry that would prevent rotation thereof with { HEAD ~ respect } to { TAIL ~ trough } 28 , in which instance corresponding holes 29 would be of a matching receiving shape
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH