Textiles: weaving – Weft manipulation – Weaving with stationary weft supply
Patent
1995-10-30
1997-09-30
Falik, Andy
Textiles: weaving
Weft manipulation
Weaving with stationary weft supply
D03D 4736, B65H 5122
Patent
active
056717830
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a weft feeder with turn separator for air jet looms with high insertion speed.
It is known that weft feeders are devices adapted to accumulate a reserve of thread in the form of turns wound on a fixed drum and to feed the loom by unwinding the accumulated turns by an extent that is equal to the length L of thread required by said loom at each beating; said length is equal to the transverse dimension, or width H, of the fabric being formed.
In the specific case of air jet looms, the feeder also has the task of preliminarily measuring the length L of thread; this task is performed in a known manner both by counting, by means of an optical sensor, the number "n" of unwound turns of thread, and by varying the diameter D of the winding drum, wherein:
The unwinding of the thread is controlled by an electromagnetic braking unit which, by means of a moving probe, stops the advancement of the thread when the n-th turn has been reached; the diameter D of the feeder drum is adjusted so as to always be a submultiple of the width H of the fabric being produced.
In a per se known manner, the reserve of weft is wound on the feeder drum by a windmilling arm; a transport system gradually moves the turns from the base of the drum to its head, keeping them mutually separated; said transport system is typically formed by a swift composed of rods to which an undulatory motion is imparted by an angled bushing and which periodically protrude from corresponding slots of the drum. The distance between the turns, which is chosen according to the type of thread being processed in order to avoid tangles or overlapping of turns, depends on the extent to which the rods protrude with respect to the slots of the drum and can be changed significantly, for example by more than a millimeter, by varying said protrusion value slightly, for example by 2-3 tenths of a millimeter.
It is evident that when the diameter D of the drum varies, the diameter of the transporting rod-based swift must be correspondingly varied, so that said rods can continue to protrude to a preset extent from the slots of the drum which has a different diameter.
Various solutions have already been provided for this purpose which are based on the concept of dividing said drum and said rod-based swift into sectors--typically four sectors arranged at 90.degree. to each other--and of controlling the sectors by means of an element that allows to vary their radial position, particularly to expand them from a minimum-diameter position to a maximum-diameter position and vice versa.
According to some known solutions, the diameter of the rod-based swift and of the drum are changed individually by means of corresponding elements for moving the respective sectors. However, adjustment systems of this type have several drawbacks, mainly a considerable structural complexity of the shifting elements and considerable difficulty in the adjustment operations, which require long execution times and the intervention of specialized operators. These systems are furthermore not suited for automation by means of actuators driven by control units.
According to other known solutions, the diameter of the transporting rod-based swift and of the drum are changed simultaneously by means of a single element which acts on the sectors of both parts to expand and contract them to the same extent.
Known systems of this kind, despite being more advantageous than the preceding ones, have the severe drawback that they do not allow to adjust the extent of the protrusion of the rods of the swift from the slots of the drum, and accordingly do not allow to vary the distance that separates the turns from the weft reserve, with consequent difficulty in adapting the feeder to the various types of thread being processed; the distance between the turns can be changed only by replacing the angled bushing which applies the undulatory motion to the transporting rod-based swift.
SUMMARY OF THE INVENTION
A principal aim of the present invention is essentially
REFERENCES:
patent: 5046537 (1991-09-01), Maina
patent: 5201347 (1993-04-01), Maina
Castelli Rosario
Pedrini Giovanni
Zenoni Pietro
Falik Andy
Josif Albert
L.G.L. Electronics S.p.A.
Modiano Guido
O"Byrne Daniel
LandOfFree
Weft feeder with turn separator including multiple diameter swif does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Weft feeder with turn separator including multiple diameter swif, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Weft feeder with turn separator including multiple diameter swif will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2250660