treadle

A treadle is a foot-operated lever used to power machinery by manual effort. By pressing the treadle with the foot, a connected linkage or crank converts the downward motion into rotational or reciprocating motion that drives a machine.

In sewing machines, the treadle drives a flywheel connected to the machine's main shaft, turning the needle and other mechanisms. On a loom, treadles operate the heddles to raise and lower warp threads and form the weave. Treadle-driven devices can also include pedal-powered pumps and grinding wheels, where the foot motion powers a piston or wheel.

Historically, treadles were widely used before electric power became common, particularly in the 19th and early 20th centuries. They enabled independent operation in homes and small workshops. With the advent of electrically powered machines, treadles gradually declined in ordinary use, though they remain in hobbyist, educational, and restoration settings.

Designs vary, including single pedals, double- or triple-treadle arrangements to reduce fatigue and increase control, and different wheel sizes or belt configurations. Maintenance involves keeping pivots lubricated, aligning linkages, and monitoring wear on belts or cords and on the crank mechanism.