Cap screws with replaceable inserts

Claim 1

A SCREW HAVING AN ENLARGED CYLINDRICAL HEAD PROVIDED WITH A TRANSVERSE DIAMETRICAL GROOVE U-SHAPED IN CROSS-SECTION AND OF A CONSTANT WIDTH AND DEPTH EXTENDING THROUGH SAID HEAD, A BLOCK HAVING THE SAME CROSS-SECTIONAL DIMENSIONS AND LENGTH AS SAID GROOVE REGISTERING LOOSELY IN SAID GROOVE, SAID BLOCK HAVING A POLYGONAL SOCKET EXTENDING DOWNWARD THEREINTO THROUGH THE TOP THEREOF ALIGNED WITH THE AXIS OF THE SCREW, A HOOD INCLUDING A ROOF AND AN APRON DEPENDING FROM THE ROOF HAVING THE LOWER PORTION THEREOF INTERNALLY THREADED AND SCREWED DOWN UPON SAID HEAD OF THE SCREW, SAID ROOF HAVING AN AXIAL PASSAGE THERETHROUGH OF A DIAMETER AT LEAST AS LONG AS THE LARGEST DIAGONAL OF SAID SOCKET IN A PLANE AT RIGHT ANGLES TO THE AXIS OF THE SOCKET, SAID ROOF HAVING A PAIR OF DIAMETRICALLY SPACED OPENINGS THEREIN EQUIDISTANTLY SPACED FROM SAID AXIAL OPENING ADAPTED TO RECEIVE THE PRONGS OF A SPANNER WRENCH, SAID HOOD HAVING THE INTERIOR WALL OF THE UPPER PORTION OF SAID APRON FRUSTOCONICAL IN SHAPE THEREBY DEFINING A FRUSTO-CONICAL RECESS, A COMPLEMENTARY FRUSTO-CONICAL BODY REGISTRABLE IN SAID RECESS, SAID BLOCK BEING INTEGRAL WITH SAID BODY AND EXTENDING FROM THE UNDERSIDE THEREOF ALONG A DIAMETER THEREOF, SAID BODY HAVING AN AXIAL POLYGONAL SOCKET OF THE SAME NUMBER OF SIDES AS SAID SOCKET IN THE BLOCK AND BEING ALIGNED THEREWITH.