Crank Motion Substitute.—In [Fig. 109] the pinion A is mounted so that its shaft is in a vertical slot B in a frame C. The mangle rack D, in this case, has teeth on its outer edge, and is made in an elongated form. The pinion shaft moves up and down the slot and thus guides the pinion around the ends of the rack.
Mangle Wheels.—The form which is the most universal in its application is what is called the mangle wheel. In [Fig. 110] is shown a type wherein the motion in both directions is uniform.
Mangle wheels take their names from the ironing machines called mangles. In apparatus of this kind the movement back and forth is a slow one, and the particular form of wheels was made in order to facilitate the operation of such machines. In some mangles the work between the rollers is uniform back and forth. In others the work is done in one direction only, requiring a quick return.
In still other machines arrangements are made to provide for short strokes, and for different speeds in the opposite directions, under certain conditions, so that this requirement has called forth the production of many forms of wheels, some of them very ingenious.
