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