CROSS BORDER JACQUARD MACHANISM
Cross border jacquard mechanism
Cross border patterns are specially adapted to the manufacture of handkerchief, napkins, damask; table covers shawls tapestries and carpets. The arrangement of the mechanism for producing the side borders and the body or center for any of these types of woven figured fabrics present few difficulties , one portion of the upright hooks being set apart for weaving the borders and another for producing the center. When two or more jacquard machine is used one is frequently reserved for the border and the rest for the center. The harness cords are tied up to their respective sets hooks or machine and passed through the comber boards to suits the side borders and center.
The difficulties being when having woven one or more repeat of patterns it is necessary to producing a change or cross border which shall balance the side borders and make one complete square or oblong pattern. The manufacture of bordered fabrics involves the adoption of one or more other of the fallowing mechanical methods.
1) Whenever the center and the side border constitute only one repeat of pattern, it is usual to stamp two repeats of the cross border and one repeat of the center but to lace the second set of border cards the reverse way making one continuous chain so that the loom can run without interruption for change of pattern. When only a small quantity is required to be woven the cross border cards are only stamped for one repeat; this are woven forwards, before weaving the center and backwards after the center has been woven. Where a large number of webs have to be produced the former plan is sometimes adopted even when there are two or more repeats of pattern for the center to be woven withes very long length of table covers etc this plan become most expensive involving the use of many thousands of cards a greater number than the loom is capable of accommodating.
2) Two sets of cards are cut one for the center and sides and the other for the cross border the latter consisting of two repeats laced in opposite direction. As many repeats of the center as may be required are woven then by hand the cross border cards are substitute over the cards cylinder and adjusted so as to start with no 1 card and the whole sets are woven over once when the cards are again changed by hand to the first set; the operation are similarly repeated until the request quantity of material has been woven. The slowness and inconvenience of this method have led to the introducing of several semi or wholly automatic device.
3) A common method consists in employing two sets of cards with two cards cylinder as on the double lift principle. One sets of pattern cards and card cylinder controls the centre and the other set and cylinder the cross border. The cylinders are designed to strike on every pick but are only in action one at a time according to whether the centre or cross border is being woven. Whenever either cylinder has to be put into action the other must be simultaneously thrown out.Numerous inventions have been designed whereby this operation may be performed by hand or automatically. The mechanism which will perform these changes automatically is a desideratum and ideal but such motion of necessity involve very many mechanical details and complications for which reasons they do not readily find favor.
