Page:The Kinematics of Machinery.djvu/578

 550 KINEMA TICS OF MA CHIN Eli Y.

unexamined, however, we may go a step further, and make the cylin- ders 1 and 2 conaxial. We obtain in this way the chain shown in Fig. 401. It is no longer, however, constrainedly closed, for the link a can be turned about its axis, (the coinciding axes of 1 and 2), without any motion occurring in the other links, while in these

��FIG. 401.

�remaining links the chain is fixed, they move together like a single link, or rather element, relatively to a.

These conditions can be entirely altered, however. If either of

��FTP, 40-2.

�the pairs 1 or 2, let us say 2, be changed from (C) = (S ) to (S), and at the same time the chain be so arranged that the axes of 6 and 4 are not in the same plane, we obtain such a chain as is shown in

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