Page:The Kinematics of Machinery.djvu/343

Rh

The crossed-chains formed from the isosceles slider-crank chains are of less importance than the foregoing. They are formed by a method : analogous to that described in § 69, and will be called isosceles crossed turning slider-crank $$( C_2 ? C P^\text{+} )^{d=e}$$ and isosceles crossed swinging block $$( C_2 ? C P^\text{+} )^{b=a} $$

If we make $$b$$ also $$= \infty $$ however, we obtain some remarkable special cases. The normal cross-block then becomes oblique, or to