Piston for internal combustion engine

Claim 1

IN AN INTERNAL COMBUSTION ENGINE A PISTON ASSEMBLY COMPRISING, (A) A PISTON MEMBER HAVING A HEAD PORTION, (B) SAID HEAD PORTION BEING PROVIDED WITH A TOP PLANAR SURFACE AND A FIRST ANNULAR EXTERIOR SURFACE EXTENDING ON AN AXIS SUBSTANTIALLY NORMAL WITH RESPECT TO SAID TOP SURFACE, (C) SAID FIRST ANNULAR SURFACE BEING PROVIDED WITH A PLURALITY OF AXIALLY SPACED PISTON RING GROOVES, (D) AN ANNULAR RECESS BEING PROVIDED IN SIAD HEAD PORTION AT THE JUNCTURE OF SAID TOP PLANAR SURFACE AND SAID FIRST ANNULAR SURFACE TO FORM A SECOND ANNULAR SURFACE SPACED RADIALLY INWARDLY FROM SAID FIRST ANNULAR SURFACCE AND CONCENTRIC THEREWITH AND INTERSECTING SAID TOP PLANAR SURFACE AND AN ANNULAR RADIALY EXTENDING SURFACE DISPOSED INTERMEDIATE SAID PISTON RING GROOVES AND SAID TOP PLANAR SURFACE AND INTERSECTING SAID FIRST AND SECOND ANNULAR SURFACES, (E) A COMBUSTION CHAMBER CAVITY EXTENDING INTO SAID HEAD PORTION FROM SAID TOP PLANAR SURFACE, (F) AN ANNULAR CAVITY REGISTERING WITH SAID RECESS AT THE JUNCTURE OF SAID RADIALLY EXTENDING SURFACE AND SAID SECOND ANNULAR SURFACE. (G) A COLLOR MEMBER BEING PROVIDED WITH AN ANNULAR RADIALLY EXTENDING SURFACE ENGAGING SAID RADIALLY EXTENDING SURFACE OF SAID HEAD PORTION AND AN ANNULAR AXIALLY EXTENDING SURFACE ENGAGING SAID SECOND ANNULAR SURFACE OF SAID HEAD PORTION. (H) SAID ENGAGING SURFACES OF SAID HEAD PORTION AND SAID COLLOR MEMBER BEING SECURED ONE TO THE OTHER BY ELECTRON BEAM WELDING AND SAID COLLAR MEMBER CLOSING SAID ANNULAR CIVITY IN SAID SECURED POSITION, AND (I) MEANS CIRCULATING A COOLANT THROUGH SAID ANNULAR CAVITY.