Chain couplings consist of two standard-like sprocket wheels with hardened teeth (hub unhardened to facilitate fnishing) which are connected = coupled by means of a duplex heavy- duty roller chain according to DIN 8187. This results in a fexible connection which can also be detached quickly and easily, if necessary, due to the integrated chain closing link. At the same time this coupling compensates for slight misalignments. With a view to service life, however, misalignmnets should be kept at a minimum. The couplings are to be lubricated like chain drives.