Patent ID: 8402708

Claim:
A modular block apparatus, comprising: a block having a top surface, a bottom surface, and a generally cylindrical core passage extending between the top and bottom surfaces; and a locking assembly received in the core passage, the locking assembly comprising: a core having a through-bore extending therethrough defining alternating core grooves and lands; a locking rod having an array of alternating rod grooves and lands complementary to the core grooves and lands; and a rod key positioned between the locking rod and the core for retaining the locking rod in engagement with the core such that the locking rod protrudes from the top surface of the block, the rod key having an arcuate cross-section and a laterally extending lip at one end thereof such that an outer wall of the rod key mates with a semi-cylindrical passage of the core and an inner wall of the rod key mates with the locking rod lands when inserted into the core to prevent the locking rod from shifting laterally with respect to the core.