US Patent 7418875 Tension measuring method and apparatus for chain

A tension measuring apparatus and method for a chain by which tension applied to the chain is correctly and reproducibly measured is disclosed and claimed. A tension measuring method for a chain (10) comprising a pair of right and left inner plates (11), bushes (12) press-fit between the inner plates (11), a pair of right and left outer plates (13) disposed on both outsides of the inner plates (11), connecting pins (14) loosely inserted into the bush (12) and press-fit between the outer plates (13), and connected to each other characterized in that a strain gauge is applied to a position having a relation of a ratio of 1 to 1 between tension applied to the chain and an output of the strain gauge (16).