[166]. Fan for giving motion to several rods or arms at one time, used for organ composition pedal movement, &c.
[167]. Crossed lever motion with inclined contact surfaces, the levers being at right angles to one another.
Section 10.—CRANK AND ECCENTRIC GEAR.
[168]. Bent crank of round section; retains the fibre and strength of the metal.
[169]. Square forged crank. The crank arm is usually forged solid and the slot cut out by machine.
[170]. Built-up crank. There are other methods of building them. See Mechanical World, December 1885. See also [No. 182].
[171]. Single crank, usually of wrought iron, but often made with cast-iron arm.
[172]. Disc crank. This form is generally adopted when cast iron is employed, and the counterbalance weight cast upon it, to balance the connecting rod, &c.
[173]. Counterbalanced single or double crank.