Flexible sponge mop head

Claim 1

A MOP HEAD COMPRISING AN ELONGATED BLOCK OF PLIABLE SPONGE MATERIAL HAVING A LOWER WASHING SURFACE AND AN UPPER SURFACE, A ONE-PIECE ELONGATED BACKING UNIT HAVING A RELATIVELY THIN AND FLEXIBLE ELONGATED CENTRAL PORTION, THICHER RIGID ELONGATED LEADING AND TRAILING PORTIONS INTEGRAL WITH AND PARALLEL TO SAID CENTRAL PORTION AND ADJACAENT SAID UPPER SURFACE OF SAID PLIABLE SPONGE MATERIAL, SAID LEADING AND TRAILING PORTIONS BEING THICKENED IN THE DIRECTION OF THE SPONGE, MEANS ADHESIVELY SECURING SAID THICKENED RIGID LEADING AND TRAILING PORTIONS TO THE UPPER SURFACE OF SAID PLIABLE SPONGE MATERIAL, SAID CENTRAL PORTION BEING FREE OF THE SPONGE, AN ELONGATED RECESS BETWEEN SAID PLIABLE SPONGE MATERIAL AND SAID FLEXIBLE CENTRAL PORTION OF SAID BACKING UNIT, AND AN ELONGATED LONGITUDINAL GRIPPING RIDGE ON THE UPPER SURFACE OF EACH OF SAID LEADING AND TRAILING PROTIONS OF SAID BACKING UNIT EXTENDING THE LENGTH THEREOF AND A PAIR OF ELONGATED RECESSES IN THE UNDERSURFACE OF THE BACKING UNIT DEFINING SAID FLEXIBLE CENTRAL PORTIONS WHEREBY THE UNIT BREAKS AT SAID RECESSES.