Patent ID: 6988847

Claim:
A paving unit for use as part of a paving arrangement, the paving unit comprising: a top surface and a plurality of side surfaces with one of the side surfaces of the paving unit provided with at least one substantially asymmetric vertically extending tongue and at least one substantially asymmetric vertically extending recessed groove when the paving unit is in an as laid form, the tongue including a ridge portion and a substantially tapering second portion, the ridge portion and the tapering portion being spaced apart by a substantially planar intermediate portion, the tongue capable of engaging a complementary groove in first adjacent paving unit, wherein said ridge portion, and the recessed groove only opening into a side surface of said paving unit to the extent that the recessed groove permits a complementary tongue on a second adjacent paving unit to be inserted into and enclosed within the recessed groove, wherein the interengagement between the tongue on the second adjacent paving unit and the recessed groove provides interlock between the paving unit and all adjacent paving units.