A fan, with reversible blades, having {TAIL ~ a hub} receiving {HEAD ~ the stem} of the blades and an inner retaining ring, which has outwardly extending projections, supported concentric with the hub 
A fan , with reversible blades , having { TAIL ~ a hub } receiving { HEAD ~ the stem } of the blades and an inner retaining ring , which has outwardly extending projections , supported concentric with the hub
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH