The Collaborative International Dictionary of English v.0.48:

mangle \man"gle\, n. [D. mangel, fr. OE. mangonel a machine for
   throwing stones, LL. manganum, Gr. ? a machine for defending
   fortifications, axis of a pulley. Cf. Mangonel.]
   A machine for smoothing linen or cotton cloth, as sheets,
   tablecloths, napkins, and clothing, by roller pressure, often
   with heated rollers.
   [1913 Webster]

   Mangle rack (Mach.), a contrivance for converting
      continuous circular motion into reciprocating rectilinear
      motion, by means of a rack and pinion, as in the mangle.
      The pinion is held to the rack by a groove in such a
      manner that it passes alternately from one side of the
      rack to the other, and thus gives motion to it in opposite
      directions, according to the side in which its teeth are
      engaged.

   Mangle wheel, a wheel in which the teeth, or pins, on its
      face, are interrupted on one side, and the pinion, working
      in them, passes from inside to outside of the teeth
      alternately, thus converting the continuous circular
      motion of the pinion into a reciprocating circular motion
      of the wheel.
      [1913 Webster]