DOBBY LOOM:-

DOBBY LOOM:-

Earlier discussed about the dobby shedding mechanism. Now here is the loom which is used to operate the dobby is known as dobby loom.

A DOBBY loom or dobbie loom is type of floor loom that controls all the warp threads using a device called dobby. 

Image of A loom from 1890s with a dobby head.

Dobbies can produce more complex designed fabric than tappet looms, but are limited in comparison to jacquard looms. Dobby looms first operated in 1843, roundly 40 years after Joseph Marie Jacquard invented jacquard device that can be mounted on top of loom to left the individual heddles and warp threads.

The dobby is a corruption of “draw boy" which refers to the weaver’s helper who used to control the warp by pulling draw threads . A dobby loom is alternative to treadle loom. Both are the floor looms in which every warp thread on the loom attached to single shaft called a heddle. A shaft is sometimes known as harness . Each shaft controls a set of threads.

 Raising or lowering several shafts at the same time gives a huge variety of possible shed through which the shuttle containing weft can be thrown.

Image of Dobby loom control mechanism. The peg driven into the bar (hung in a loop on the left) can lift one "treadle" in a pre determined pattern like lifting the teeth of a music box . Hoogly Distt.West Bengal. 2019.

A manualy dobby use a chain of bars or lags each of which pegs inserted to select the shaft to moved. A computer assisted dobby loom uses a set of solenoid or other electronic device to select shafts.

Activation of this solenoids is under the control of a computer program. In either case the the selected shafts are raised or lowered by either leg power on a dobby pedal or electric or other power sources.

Image of Steam powered 1894 dobby loom . Queen Street Mill Museum.

Mannual operation of a dobby loom.

On a treadle loom, each foot operated treadle loom is connected by a linkage called tie-up to one or more shafts. More than one treadle can operate single shaft. The tie-up consist of cords or similar mechanism linkage tying the treadles to the lams that actually lift or lower shaft.

On treadle operated looms, the number of shed is limited by the number of treadles available.

An eight shaft loom can create 254 sheets. There are actually 256 possibilities which is 2 to the eight power, but having all threads up or all threads down is not very useful.

Most eight shaft floor looms have only ten to twelve treadles due to space limitations. This limits the weaver to ten to twelve distinct sheds. It possible to use both feet to get more sheds, but this is a rarely done by practice. It is even possible to change, tie-up in the middle of weaving a cloth, but this is tedious process . So this too is rarely done.

With a dobby loom all 254 possibilities are available at any time. This vastly increases the number of cloth designs available to the weaver . The advantage of a dobby loom becomes even more pronounced on looms. With 12 shafts (4094 possible sheds) 16 shafts (65,534 possible sheds) or more . It reaches its peak or a Jacquard loom in which , each threads are controlled individually.

Another advantage of a dobby loom is the ability to handle much more sequence in the pattern. A weaver working on a treadle loom must remember the entire sequence of treadling that make-up the pattern, and must keep track where they are in the sequence at all times. Getting lost or making a mistake can ruin the cloth being woven. On a mannual dobby the sequence thry makes-up the pattern is represented by the chain of boddy bars. The length of the sequence is limited by length of dobby chain. This can easily be several hundred dobby bars, although an average dobby chain will have approximately fifty bars.

DOBBY CLOTHS:-

It is woven fabric produced on the dobby loom , characteristic by small geometric pattern and extra texture on the cloth . The warp and weft threads may be the same color or different satin threads are particularly effective in this kind of weaves as their texture will highlight the pattern.

Image of Dobby woven fabric.

Polo shirts are usually made with dobby . Pique fabrics are a type of dobby construction.

Ref://en.m.wikipedia.org