KINEMATICS OF MACHINERY.
If the axial distances 1.2 and 2.3 of a compound chain (C C") be made equal, the shafts 1 and 3 may be made conaxial. This gives us the chain represented in Fig. 280, where I and c, as before, form parts of the same (ternary) link, while a and d can move
independently. We shall call a train of this kind, in which the centres of the last wheel are, as it were, turned back into coin- cidence with that of the first, a reverted train. This form of train plays no unimportant part in machine practice. Among its other
applications it has been used as a chamber-gear, but in all cases with the variation from the forms already described that it has non-circular wheels, the chain therefore being (&& and the mechanism i