Page:The Kinematics of Machinery.djvu/498

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KINEMATICS OF MACHINERY.

The analogy between fluid click-trains and those consisting solely of rigid bodies exists equally in those cases where the trains are employed in complete mechanisms or machines. The me- chanism Fig. 350, which represents simply a common lift pump, corresponds to the ratchet-train of Fig. 351, which we have already examined. The pump-barrel c, represents the frame c of

FIG. 346.

FIG. 347.

the ratchet-gear, the suction-valve the lower pawl b, the bucket- valve the ratchet-pawl b v the prism o-cyl in dric arrangement of bucket and barrel corresponds to the prism pairing between the bar c x and the frame c.

The double acting ratchet-train, Fig. 352, which we already know, exactly represents the Stoltz pump, Fig. 353. The pump and

FIG. 348.

FIG. 349.

the ratchet-train correspond part for part ; the two buckets c and c x with their rods, are the two bars c and c x ; the valves I and \ are the ratchet pawls, the pump-barrels and frame d correspond to the guides and frame d of the ratchet-train. The passing of the one click over twice as many teeth as correspond to the distance through which the rack is lifted has* also its parallel in the pump, the water moving relatively to the descending piston