US Patent 7681805 Irrigation dripper and pipe

A dripper adapted to be bonded to interior of an irrigation pipe during manufacture and to be associated with an outlet opening in said pipe. The dripper comprises an outwardly facing surface adapted for the bonding, an outlet area associated with the surface, and at least one bulge near the outlet area. The bulge defines an outermost portion of the surface at least during manufacture of the pipe, and is adapted to form, when the dripper is bonded to the pipe, a raised outlet region in the pipe associated with the bulge. The bulge and outlet area are designed so as to form the raised outlet region suitable for at least a part of the outlet opening to be formed therein and be defined by the material of the pipe.