Interlocking chain unit

An interlocking chain unit that forms a rigid chain part by forming an interlock between a pair of interlocking chains, each including an inner tooth plate and an outer tooth plate arranged externally to the inner tooth plate, the interlocking chain unit comprising:

• a pair of case plates arranged to be separate from and external to the pair of interlocking chains, wherein the pair of case plates supports a sprocket shaft such that the sprocket shaft can rotate freely;
• a guide plate arranged between the case plates, the guide plate guiding the interlocking chains;
• and
• a stepped rod that determines the position of the pair of case plates and that of the guide plate relative to each other, wherein
• the stepped rod has a small-diameter part and a large-diameter part, each extending in a chain width direction,
• the large-diameter part is near a first case plate forming the pair of case plates with respect to the center of the stepped rod,
• the large-diameter part has a guide plate side step near the guide plate and a case plate side step near the first case plate,
• the small-diameter part passes through a passage hole of the guide plate,
• the stepped rod has opposite end portions fitting in respective countersunk holes formed in inner surfaces of the pair of case plates,
• the guide plate side step abuts on a rim of a passage hole of the guide plate, and
• the case plate side step abuts on a rim of a countersunk hole of the first case plate.