Well screen

Claim 1

A SELF-CLEANING WATER WELL SCREEN WHICH IS SUBSTANTIALLY IMMUNE TO CLOGGING DURING INSERTION INTO THE GROUND, SAID WATER WELL SCREEN COMPRISING, IN COMBINATION: AN ELONGATE TUBE OF SYNTHETIC MATERIAL HAVING A BODY PORTION AND A PLURALITY OF PARALLEL LONGITUDINALLY EXTENDING AND CIRCUMFERENTIALLY SPACED IMPERFORATE RIBS PROJECTING OUTWARDLY FROM SAID BODY PORTION, GENERALLY OPEN CHAMBERS BOUNDED BY ADJACENT RIBS AND THE OUTER SURFACE OF SAID BODY PORTION BETWEEN ADJACENT RIBS, SAID BODY PORTION BEING PROVIDED BETWEEN ADJACENT RIBS WITH A PLURALITY OF OPENINGS ARRANGED ALONG THE LENGTH OF SAID BODY PORTION TO PLACE SAID CHAMBERS INTO COMMUNICATION WITH THE INTERIOR OF SAID BODY PORTION; AND FILTERING MEANS INCLUDING A STRIP OF MATERIAL FORMING A PLURALITY OF SLIGHTLY SPACED APART TURNS ENCIRCLING SAID TUBE AND ENGAGING SAID RIBS THEREBY PARTIALLY TO CLOSE THE EXTERIOR BOUNDARY OF SAID CHAMBERS AND FORMING BETWEEN THE ADJACENT TURNS A CONTINUOUS SLOT THROUGH WHICH WATER MAY PASS, SAID STRIP BEING GENERALLY WEDGE-SHAPED IN CROSS SECTION AND INCLUDING OUTER AND INNER SURFACES JOINED BY INCLINED SIDE WALLS, THE INNER SURFACE OF SAID STRIP BEING THE NARROWEST PORTION THEREOF, SAID INNER SURFACE ENGAGING SAID RIBS THEREBY TO RENDER THE SLOT V-SHAPED AND TO PROVIDE SELF-CLEANING FILTERING SLOTS, SAID STRIP HAVING RELATIVELY SHARP OPPOSITE OUTER EDGES DEFINED BY SAID INCLINED SIDE WALLS AND THE OUTER SURFACE THEREOF, SAID OUTER SURFACE BEING CONVEX BETWEEN SAID OUTER EDGE TO PROVIDE A UNDULATED OUTER SURFACE THEREBY TO PREVENT CLOGGING OF SAID FILTERING MEANS DURING INSERTION OF THE WELL SCREEN INTO THE GROUND, THE INNER AND RIB-ENGAGING SURFACE OF SAID STRIP BEING SLIGHTLY CONCAVE TO DEFINE WITH SAID INCLINED SIDE WALLS SHARP OPPOSITE INNER EDGES ALONG THE INNER SURFACE THEREOF, SAID SHARP OPPOSITE INNER EDGES BEING EMBEDDED IN SAID RIBS TO MAINTAIN THE TURNS OF SAID STRIP IN SPACED RELATIONSHIP FROM ONE ANOTHER.