Abstract: A modular block apparatus including 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 including 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.

Abstract: A modular block apparatus including 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 including 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.

Abstract: A modular block apparatus includes first and second blocks, each block having a generally upwardly protruding locking member and an internal recess sized to receive the locking member of the other block, such that the blocks can be assembled with one block above the other. The blocks are secured together in a vertical direction by relative lateral movement of the locking member and the internal recess. A locking device is provided to prevent relative lateral movement of the locking member and the internal recess so as to retain the blocks in a connected condition. The locking member may be an integral hook, a separate hook, or a cylindrical locking rod. If a hook is used, its orientation relative to the block may be varied. A variety of structures may be built up from the modular blocks.

Abstract: A modular block apparatus includes first and second blocks, each block having a generally upwardly protruding locking member and an internal recess sized to receive the locking member of the other block, such that the blocks can be assembled with one block above the other. The blocks are secured together in a vertical direction by relative lateral movement of the locking member and the internal recess. A locking device is provided to prevent relative lateral movement of the locking member and the internal recess so as to retain the blocks in a connected condition. The locking member may be an integral hook, a separate hook, or a cylindrical locking rod. If a hook is used, its orientation relative to the block may be varied. A variety of structures may be built up from the modular blocks.