Check valves

Claim 1

A CHECK VALVE, COMPRISING A VALVE CASING HAVING AN INLET AND AN OUTLET, A GUIDE BODY MOUNTED IN SAID CASING AND SPACED FROM THE INSIDE WALLS OF THE CASING TO LEAVE A FLOW PASSAGE THROUGH THE CASING FROM THE INLET AROUND THE GUIDE BODY TO THE OUTLET, SAID GUIDE BODY HAVING AN AXIAL HOLE THERETHROUGH HAVING AT LEAST TWO PORTIONS WITH DIFFERENT DIAMETERS, THE PORTION WITH THE LARGER DIAMETER BEING ADJACENT THE OUTLET OF THE VALVE CASING, AND SAID GUIDE BODY HAVING A PLURALITY OF SMALL BORES EXTENDING RADIALLY FROM THE LARGER PART OF THE AXIAL BORE INTO THE FLOW PASSAGE AND HAVING AT LEAST THE ENDS THEREOF INCLINED TOWARD THE INLET OF SAID VALVE CASING, SAID SMALL BORES OPENING OUT OF SAID AXIAL BORE A SHORT DISTANCE ABOVE THE PORTION OF THE AXIAL BORE HAVING THE SMALLER DIAMETER, A VALVE SEAT AROUND SAID INLET TO SAID VALVE CASING, AND A VALVE BODY COOPERABLE WITH SAID VALVE SEAT AND HAVING A STEM THEREON EXTENDING THROUGH SAID SMALLER DIAMETER PORTION OF SAID AXIAL BORE AND HAVING A PISTON ON THE END THEREOF SLIDABLE IN THE LARGER DIAMETER PORTION OF SAID AXIAL BORE, SAID GUIDE BODY HAVING A RECESS ON THE END THEREOF ADJACENT SAID VALVE CASING INLET HAVING A DIAMETER ONLY SLIGHTLY LARGER THAN THE DIAMETER OF SAID VALVE BODY AND INTO WHICH SAID VALVE BODY FITS IN PISTON-CYLINDER RELATIONSHIP, AND SAID GUIDE BODY FURTHER HAVING A FLOW RESTRICTING BORE BETWEEN THE SAID LAST-MENTIONED RECESS AND THE LARGER DIAMETER PORTION OF SAID AXIAL BORE.