Textiles: weaving – Special-type looms – Multiple-shed
Reexamination Certificate
2002-04-22
2004-08-03
Calvert, John J. (Department: 3765)
Textiles: weaving
Special-type looms
Multiple-shed
C139S043000, C139S037000, C139S097000
Reexamination Certificate
active
06769456
ABSTRACT:
This invention relates to a device for separating warp yarns on a face-to-face weaving machine, comprising at least one separating means and a holding device provided to keep the separating device at a holding height and to adjust this holding height.
On a face-to-face weaving machine two backing fabrics are woven simultaneously above one another. For that purpose backing warp yarns (for instance tension warp yarns and binding warp yarns) are provided on the weaving machine. During consecutive weft insertion cycles an upper shed is formed between a number of backing warp yarns, and a lower shed is formed between a number of other backing warp yarns. This shed forming occurs by means of shed forming means that can bring the warp yarns into two different positions. Into these sheds each time a weft yarn is inserted during the consecutive cycles.
The ground warp yarn supply is provided on warp yarn beams, for instance a tension warp yarn beam and a binding warp yarn beam. From those beams the backing warp yarns are conducted to the weaving machine. Before the yarns reach the shed forming means they are separated into two layers situated above one another. An upper layer with the backing warp yarns, which are needed to weave the upper backing fabric and a lower layer with the backing warp yarns, which are needed to weave the lower backing fabric.
It is generally known to keep these two layers of backing warp yarns separated from one another by means of two yarn separating cylinders. These cylinders are situated above one another between the two yarn layers, the warp yarns of the upper layer running over the top of the upper yarn separating cylinder, and the warp yarns of the lower layer touching the lower side of the lower yarn separating cylinder. In this manner, the warp yarns of the two layers are kept separated from each other at a vertical distance and are kept well apart.
In order to prevent the backing warp yarns from becoming slack in one of their two positions, each yarn separating cylinder has to be installed exactly in the bisector plane of the respective shed. It is known to attach these yarn separating cylinders to the weaving machine by means of a holding device enabling the holding height to be adjusted and to be adjusted in the warp-direction.
In a known adjustable device to separate the yarns on a face-to-face weaving machine the separating cylinders are connected to respective holders, which extend horizontally in the warp-direction towards the yarn beams. These holders are provided with a number of holding bores separated from one another in the warp-direction. A vertical cylindrical bar, which is fixed to the frame of the weaving machine, extends through a holding bore of both holders. In this manner, the holders are provided on the bar in a slidable manner and they may be attached to this bar at a height as desired by means of a clamp joint. These clamp joints are fixed by means of a bolted joint. The position of the separating cylinders is adjustable in the warp-direction by using another holding bore.
However, this known device has a number of important disadvantages. When adjusting a new holding height of the separating cylinders, after loosening the clamp joint, the holder remains in its original position on the vertical cylindrical bar because of its self-clamping action. Only when driving a wedge into the clamp opening, the clamp joint opens all of a sudden and the separating cylinder will move downwards or upwards under the influence of its own weight and/or under the influence of a tractive force, exerted on the separating cylinder by the warp yarns. Because of this, the original adjustment will be totally lost. When adjusting a separating cylinder at a new holding height it is however desirable that the original holding height can be used as a reference. For that purpose, with this device, the original position should be marked or measured first before loosening the clamp joint. Than the new position can be compared with the original position either by referring to this marking, or by measuring once again the new position and by comparing the new measured value with the measured value of the original position. Therefore adjusting the separating cylinders is a complicated and time-consuming job and, moreover, it cannot be done with great precision.
Moreover, when loosening the clamp joint by driving in a wedge, there is always a risk that the separating cylinders start falling downwards or moving upwards under the influence of their own weight and/or under the influence of the tractive force exercised on the separating cylinders by the backing warp yarns. This movement of the separating cylinders can be dangerous, so that the person who carries out this job should be prepared for a temporarily unsafe situation.
The purpose of this invention is to provide a device to separate the warp yarns on a face-to-face weaving machine by means of which the above-mentioned disadvantages can be remedied and which therefore will enable the holding height to be adjusted in a simple and exact manner under safer conditions.
According to this invention this goal is achieved by providing a device to separate warp yarns on a face-to-face weaving machine, which has the characteristics mentioned in the first paragraph of this description and the holding device of which comprises a threaded adjusting means, whereas the adjusting means is provided in such a manner that its rotation causes the separating means to be moved, because of which the holding height is changed and whereas the adjusting means can maintain the separating means at the holding height adjusted.
With this device, the holding height of the separating means can be changed by rotating a threaded adjusting means. A similar adjusting is particularly simple and can be done with great precision. Because the adjusting means is also provided to hold the separating means at the adjusted height, during this adjusting operation, any unwanted and dangerous upward and downward movements of the separating means, under the influence of its weight and/or the tractive force of the warp yarns, are avoided. Therefore, with the device according to this invention, adjusting the holding height can be done in a far more exact and simple manner, and under safer conditions than with the known devices.
In a preferred embodiment of this invention the adjusting element is attached rotatably at a fixed height and this element is provided to move the separating element by means of its screw thread.
For instance, the adjusting element may be carried out as an adjusting element (for instance an adjusting spindle) attached at a fixed height with a threaded handle extending vertically, engaging in a bore of the separating element or of a part connected to it, so that the rotation of the adjusting spindle in the bore causes the adjusting means to be moved up or down (depending on the sense of rotation).
Preferably, the holding device is also provided to adjust the position of the separating element in the warp-direction.
The holding device can also be carried out with a movable intermediate part to which the separating means is connected, the position of the separating element being adjustable in the warp-direction with respect to the intermediate part and the adjusting means being provided to move the intermediate part in order to adjust the holding height. Thus a simple holding device is obtained where adjusting the height and adjusting in the warp-direction can occur on the same adjusting point.
In a particular embodiment the holding device comprises also a fixedly attached support, whereas the adjusting means makes a connection between the support on the one hand and the separating means, or a part connected to this separating means, on the other hand.
If the intermediate part is attached in a movable manner on a part of the support extending in a practically vertical direction a device is obtained with a holding height that can be adjusted in a very easy and accurate manner.
In a very advantageous embodiment of this invention reference m
Debaes Johnny
Maes Dominique
Creighton Wray James
Muromoto Jr. Robert H.
N.V. Michel Van de Wiele
Narasimhan Meera P.
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