Patent ID: 8413473

Claim:
A mechanical key code verification system comprising: a mechanical key; and a lock apparatus into which the mechanical key is insertable; the mechanical key including: a key body having at least one plane; and a key code pattern formed on the at least one plane of the key body and including a plurality of recessed portions and a plurality of non-recessed portions, the plurality of recessed portions and the plurality of non-recessed portions arranged in a plurality of rows and a plurality of columns; the lock apparatus including: a plurality of tumblers, each of the plurality of tumblers associated with one of the plurality of recessed portions or one of the plurality of non-recessed portions in the key code pattern when the mechanical key is inserted into the lock apparatus to a fully inserted position; and a plurality of biasing members respectively biasing the plurality of tumblers; wherein the lock apparatus mechanically verifies the key code pattern when the mechanical key is inserted into the lock apparatus to the fully inserted position based on whether or not the plurality of tumblers are aligned with the associated ones of the plurality of recessed portions and plurality of non-recessed portions, wherein oblique angles are formed between the plurality of rows and the plurality of columns, and wherein the oblique angles are such that the perimeter of each of the plurality of tumblers completely enters only the perimeter of the associated recessed portion at the fully inserted position and at least one of the plurality of tumblers overlaps with a non-associated recessed portion of the mechanical key over an overlapping area but does not completely enter the non-associated recessed portion when the mechanical key is inserted into the lock apparatus to a partially inserted position before the fully inserted position.