2009031508 A1 abstract separate covers for protruding portions of discs of automatic swimming pool cleaners are addressed the covers may be placed onto protrusions such as fins and removed from the fins as needed version of the covers are made of material more rigid and having lower coefficient of friction than the fins to discourage lateral bending of the fins and decrease frictional contact of the fins with pool surfaces application_number US 88829407 A description depicted in fig1 4 is exemplary member or cover 10 of the present invention presently preferred versions of cover 10 are one piece structures molded into a rigid shape in particular cover 10 typically is designed to be substantially harder i e more rigid than 80 a shore the typical hardness of its associated disc 14 alternatively cover 10 may comprise more than one piece whether a one or multi piece structure cover 10 may include generally vertically oriented portion 18 and generally horizontal portion 22 as shown in fig1 4 portion 18 may extend upward from portion 22 portion 18 also may be curved generally matching the shape of leading edges 26 of fins 30 spaced radially about disc 14 see fig3 5 if protrusions shaped other than fins 30 extend outward beyond periphery 34 of disc 14 portion 18 may of course be shaped differently than as shown generally vertically oriented portion 18 may comprise wall 38 and at upper end 42 cap 46 wall 38 has generally u shaped cross section thus forming hollow area 50 into which fin 30 may be frictionally fitted cap 46 functions as a stop contacting uppermost part 54 of fin 30 when cover 10 is properly positioned generally horizontal portion 22 may include spaced walls.