The extensions each includes a curved surface formed therein for engaging with the protrusions of {HEAD ~ the stops} and for guiding {TAIL ~ a rotation} of the legs of the plate relative to the extensions of the block 
The extensions each includes a curved surface formed therein for engaging with the protrusions of { HEAD ~ the stops } and for guiding { TAIL ~ a rotation } of the legs of the plate relative to the extensions of the block
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH