The tines 38 are solid, rigid structures in {TAIL ~ 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 {HEAD ~ the screen} 30 
The tines 38 are solid , rigid structures in { TAIL ~ 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 { HEAD ~ the screen } 30
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL 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 HEAD OTH