Textiles: weaving – Warp manipulation – Shedding
Patent
1981-10-05
1983-11-22
Kee Chi, James
Textiles: weaving
Warp manipulation
Shedding
139 65, 139455, D03C 320, D03C 306
Patent
active
044163100
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to improvements of shed opening devices for open-shed Jacquard machines connected for weaving fancy cloths and more particularly, though not exclusively, for silk fabrics.
It is known that in order to weave fabrics with very large patterns and with a high density of warp threads, such as pictures, tapestry works or other drawings, manual looms have hitherto been used. This manufacturing process obviously entails considerable labor costs and very long manufacturing times.
If it is desired to manufacture such fabrics on mechanized looms, it is necessary to provide a large number of conventional or Verdol Jacquard machines capable of opening the shed to permit passage of the weft threads. If it is contemplated to manufacture a fabric comprising 10,000 warp threads for a loom having a width of 140 cm, the actuation of the heddles adapted to open the shed will have to be effected by a number of Jacquard machines varying between 8 and 10. It is easily understood that such a number of these devices is not compatible with the space available above a loom of 140 cm in width and that in addition the synchronous drive of these machines could only be obtained at the cost of an intricate installation. Finally the cost of such a mechanism would be prohibitive.
The improvements which form the object of the present invention aim at providing a warp threads actuating device on a loom with a view to operate the opening of the shed starting from an information derived from a perforated paper, a magnetic band or the like, the cumbersomeness of which may be reduced in such manner that it may control a very large number of heddles vertically disposed near each other, its manufacturing cost remaining rather low.
The invention further concerns a device of the kind described which may be divided into modules separable from each other in such manner that if the density of the warp threads of the fabric is reduced it may be possible to eliminate a certain number of modules without having to disassemble the whole harness. When for instance one of every two modules is disassembled or at least eliminated, the heddles do not all have a vertical orientation, they are on the contrary slightly oblique, but without this inclination having an unfavorable effect with respect to the shed at the open position thereof.
In accordance with the invention, the blades associated with the heddles pass through a first plate provided with small bars and through a second plate having apertures, these blades each carrying a shoe and a catch, this shoe always resting against the second plate in such manner that the reciprocatory translation of this latter causes the downward motion of the heddles, except when the blade is actuated for upward displacement by the corresponding small bar of the first plate. This occurs when the small bars of the first plate engage the catches of the selected blades when the first plate is reciprocated in order to raise the selected heddles. Blade deflecting means are further provided to cause the small bars to escape the blades which have not been selected.
Since the fancy fabrics which it is contemplated to manufacture in a mechanized manner are generally made of delicate threads and of delicate materials such as silk, it is necessary to reduce to a maximum degree the tension of these threads at the time of the opening of the shed in order to avoid permanent deformations. For this purpose, the double-lift raising-and-lowering system is used, that is to say a sheet of warp threads is raised while the other threads are lowered through the same distance equal to half the height of the shed. It is thus possible to obtain fancy fabrics of high quality owing to the fact that, the lowering and raising strokes being equal, all the threads undergo the same tension.
The annexed drawings, given by way of example, will permit a better understanding of the invention, of the characteristics which it possesses and of the advantages which it may afford:
FIG. 1 is a diagrammatical view of a controlling device ac
REFERENCES:
patent: 1214449 (1917-01-01), Fuchs
patent: 1721787 (1929-07-01), Nakanishi
Chi James Kee
Verdol S.A.
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