Dobby loom

A Dobby Loom is a loom in which each harness can be selected without using treadles; a manual dobby uses a chain of bars or lags each of which has pegs inserted. The pegs select the harness to be moved. A computer assisted dobby loom uses a computer program to select which harness is to be moved. In either case the harnesses are lifted or sunk by either legpower on a dobby pedal or electric or other power sources. This is in contrast to a treadle handloom, where the harnesses are attached by cords to a limited number of different treadles to select and move the harnesses.

Dobby looms allow a huge variety of weave structures which a treadle loom might not, due to the lack of treadles. A floorloom is limited in the amount of treadles it can use within the loom frame, but a dobby need only add bars to the dobby chain to enlarge the loom's weave capacity. A normal eight harness floorloom has ten or twelve treadles but a dobby device mounted on the same loom will use a chain of bars ranging from twelve to seventy. The average dobby chain will have approximately fifty bars.

A Jacquard loom is an example of an adaptation from a dobby loom. A Jacquard device mounted atop a loom will lift the individual heddles and warp threads. The individual heddles and warp threads can be controlled by a computer or a series of punched cards which select them to rise or fall. Power is usually supplied to the loom to move the many heddles involved. Jacquard weaving can be used to produce some quite intricate patterns.