The engineer's sketch-book of mechanical movements, devices, appliances, contrivances and details employed in the design and construction of machinery for every purpose

by Thomas Walter Barber

[1193]. Screw and toggle press; a modification of [No. 1189].

[1194]. Double ram hydraulic press for two pressures; the small ram is employed to give the first pressure, the large ram then finishes the pressing.

See also [Section 13].

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Section 64.—POWER AND SPEED, CONTRIVANCES TO VARY.

(See Mechanical Powers, [Section 53].)

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Section 65.—QUICK RETURN MOTIONS.

Employed for machines having a slow movement one way, and a quicker return movement.

[1195]. Slot lever and crank motion; gives a varying speed, quickest when the crank pin is at the bottom centre, and slowest when at the top, with a slight pause at each end of stroke.