PURPOSE: To reduce a noise so as to contrive improvement of durability by setting a chain pitch of a chain belt to a specific dimensional range so as to bring a friction plate of 20-pitch or more into contact with a pulley when the belt is wound on a set of the pulleys in a minimum permissible contact diameter by engagement with the cone-shaped pulley.
CONSTITUTION: Since a chain belt C is not suited for practical use by decreasing dimensions of each part in the chain belt in the case of mounting a friction plate to a chain when a chain pitch is provided 8mm or less, and since a device total unit is enlarged when the chain pitch is set 11mm or more, in the chain belt C, it is constituted by setting the chain pitch to a range of 8mm to 11mm. While because such constitution is provided as bringing the friction plate of 20-pitch or more into contact with a pulley 1 in a minimum permissible contact diameter in the case of contact of the chain belt C with the pulley 1, a bending angle of the chain can be small held. Thus, a noise at the time of contact is reduced, and further wearing can be prevented.