Mechanism converting reciprocating into rotating motion
For the device that detects that a train wheel has passed a particular location, see Treadle (railway).
A treadle loom; the treadles raise and lower the two heddles. The heddles are connected by a rope over the heddle pulleys, so that they rise and fall alternately. One treadle is attached to the bottom of each heddle.
Atreadle (from Old English: tredan, "to tread") is a foot-powered lever mechanism; it is operated by treading on it repeatedly. A treadle, unlike some other types of pedals, is not directly mounted on the crank (see treadle bicycle for a clear example).
Most treadle machines convert reciprocating motion into rotating motion, using a mechanical linkage to indirectly connect one or two treadles to a crank. The treadle then turns the crank, which powers the machine. Other machines use treadles directly, to generate reciprocating motion. For instance, in a treadle loom, the reciprocating motion is used directly to lift and lower the harnesses or heddles; a common treadle pump uses the reciprocating motion to raise and lower pistons.
Before the widespread availability of electric power, treadles were the most common way to power a range of machines. They are still widely used as a matter of preference and necessity. A human-powered machine gives the human operator close, instinctive control over the rate at which energy is fed into the machine; this lets them easily vary the rate at which they work. Treadle-operated machines are also used in environments where electric powerisnot available to power electric machinery.
[edit]A tailor in Chad with a treadle sewing machine
A treadle is operated by pressing down on it repeatedly with one or both feet, causing a rocking motion.[1] This movement can then be stored as rotational motion via a crankshaft driving a flywheel. Alternatively, energy can be stored in a spring, as in the pole lathe.
Today the use of treadle-powered machines is common in areas of the developing world where other forms of power are unavailable. It is also common among artisans, hobbyists and historical re-enactors.[2]
Some treadle looms in Africa and South Asia use toggles on a string as treadles. The toggles are held between the weaver's toes.
Dictation using a treadle-powered cylinder phonograph, circa 1897
