{HEAD ~ The tines} 38 are solid, rigid structures in the embodiment shown in FIGS 2 and 4, but may be brushes or a similar, somewhat flexible structure which will effectively dislodge obstructions which blind {TAIL ~ the screen} 30 
{ HEAD ~ The tines } 38 are solid , rigid structures in the embodiment shown in FIGS 2 and 4 , but may be brushes or a similar , somewhat flexible structure which will effectively dislodge obstructions which blind { TAIL ~ the screen } 30
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH