314
KINEMATICS OF MACHINERY.
To put the formula into the contracted shape we have to notice that the chain consists of two parallel cylinder-pairs and two pairs of prisms normal to each other; we must therefore write it
FIG. 243.
The mechanism (CIP^Y=\ In considering the mechanisms which can be formed from the chain before us, we may begin, as before, by placing it upon d. We notice at once that the coupler "b is kinematically exactly equal to the frame d, and lies exactly similarly in the chain, having namely a link C ... || ... C on one side of it,
FIG. 244.
and a link P ... JL ... P on the other ; the mechanisms (C" 2 ' and (C' 2 'P^-) b are therefore identical. In Fig. 243, d is made the fixed link. Following the analogy of our former nomenclature we may call the train a turning double slider-crank, or shortly turning double slider, for we obtain it by the addition of a second sliding pair to the turning slider-crank. The train (
