US Patent 10508457 Panel with complimentary locking elements

A panel having a pair of complementary locking elements at mutually opposite panel edges. The locking elements are positively locking holding profiles with a locking groove and a complementary locking tongue respectively. At least at the edge of one of the holding profiles the panel surface has an edge break portion. The holding profile provided with the edge break portion has an upper contact surface beneath the edge break portion and the complementary holding profile has a complementary upper contact surface arranged substantially parallel thereto. A butt joint is produced by contact of two contact surfaces. The butt joint is inclined relative to the panel surface. One of the contact surfaces is associated with a tongue and is inclined downwardly toward the free end of the tongue in question and the complementary upper contact surface is associated with a groove and is inclined downwardly toward the bottom of the groove.