US Patent 9068584 Apparatus and methods for connecting mats

An adjustable locking pin for connecting at least first and second overlapping mats includes an elongated main body, an elastomeric seal extending around the periphery of an enlarged head of the main body and an elongated rotor threadably engaged in a bore of the main body. The rotor is rotatable through at least two 360 degree revolutions of rotation relative to the main body and includes a foot at its bottom end. The rotational adjustability of the rotor allows the first and second mats to be tightly held together.