KR20060119770A - Carrying gripper for weaving looms with (anti-loop) device to avoid anticipated weft gripping - Google Patents

Abstract

A carrying gripper for weaving looms with an anti-loop device to avoid the anticipated weft gripping is provided to remove the loop formation phenomenon by a weft. A long metal element(1) has substantially a flat shape and is inserted into a sidewall of a gripper body by a screw(2). The screw is operated with an eyelet formed at the rear of the element. A deflector(6) is formed integrally with the element for forming the rear of a weft inlet channel and extended toward the rear of the gripper at the area nearby of the entrance of elastic grasping members(8,9). An end of the extension portion forms a resting surface for sliding the weft and has the angle from 0 to 90 degrees.

Description

 CARRYING GRIPPER FOR WEAVING LOOMS WITH (ANTI-LOOP) DEVICE TO AVOID ANTICIPATED WEFT GRIPPING}

The features and advantages of the present invention will become more apparent from the following description of the preferred embodiments of the present invention.

1 is a side view (weft feeder side) of a transport gripper with an anti-loop device according to the present invention.

Figure 2 is a side view (fabric side to be woven) of the transport gripper of Figure 1;

3 is a plan view of the gripper of FIG.

4 is a cross-sectional view taken along the line IV-IV of FIG. 1 or FIG.

5 is a front view of the gripper of FIG.

<Explanation of symbols for the main parts of the drawings>

The present invention relates to a carrying gripper for weaving looms, and more particularly to this type of gripper having a device for avoiding anticipated conventional gripping.

As is well known to those skilled in the art, during weaving weft threads (or other weft yarns when weaving them with other types or colors of weft yarns), weft yarns are inserted and body needles by reeds against the fabric. After weaving, the wefts are not cut from the same fabric but remain connected until such wefts are reselected by the loom for new insertion. Optionally, between the point of connection to the fabric (with the possible presence of the deflector, if there are many wefts to be woven and therefore some wefts remain unused during many continuous loom strokes) and the corresponding weft feeder A weft thread is pulled along an oblique line traversing the insertion passage of the gripper, grasped by the gripper, and then carried through the shed.

While the gripper enters the opening after the weft is gripped by the gripper, a cutting device is still involved which cuts the weft end connected to the fabric, thereby allowing correct insertion into the opening of this weft. Therefore, the exact moment at which weft cutting is performed must be controlled very precisely. In practice, it is necessary to cut at the exact time when the weft thread is sufficiently gripped by the resilient gripping means of the carrying gripper to prevent the weft thread from exiting the gripper within the first half of the opening, but in the middle of the opening it is not necessary to provide a weft replacement with the drawer gripper. Do not.

Certainly, the greater the importance of the moment at which the weft inserted is cut, the smaller the count of the weft processed. Indeed, in this case, if weft cutting occurs with a delay, it is easier for thin wefts to enter deeply into the resilient gripping means of the conveying gripper, which consequently provides the same high retention strength upon weft replacement. Since the tensile strength of the thin weft yarn is obviously somewhat smaller, it is easy to inevitably cause breakage of the weft yarn when weft replacement with the draw gripper is such that the strength is smaller than the above-mentioned holding strength.

As a result, a gripper specifically designed to handle thin wefts has been designed and proposed, although the shape and elastic strength of the resilient retaining means have been thoroughly designed and adjusted to minimize the above-mentioned inconveniences, yet a completely satisfactory solution has been achieved. I don't get it. The discomfort found in weaving thin wefts continues to occur with these types of grippers, albeit to a lesser extent, as described above. This type of solution is inconvenient for the weaver, and the weaver must continue to replace the gripper each time weaving the article with a thin weft, and also face problems when weaving articles containing wefts with different counts. It is not even allowed to do it.

In view of the fact that the inconvenience of breaking the weft upon replacement, or, conversely, the inconvenience of not holding the weft sufficiently firmly by the carrying gripper, arises in the gripper specially designed for inserting a weft yarn to a certain extent, the applicant of the weft yarn Intensive study of the gripping mechanism examined the nature of the causes causing the problems described above.

After this study, the Applicant finally confirmed that one of the main reasons for determining the defect of the phage examined above was in the occasional irregular pattern of weft in the cutting area. Indeed, the portion of the weft between the gripper and the fabric, i.e., where the weft cutting later occurs before the weft is inserted into the opening, especially when the weft is thin, forms a loop in which the weft is originally aligned but arbitrarily shaped and arranged Thus, it is not always kept taut along the oblique line upon contact with the gripper.

The formation of such a loop depends precisely on the fact that because the weft is thin, the weft is quickly inserted between the gripper's elastic gripping means and locked in advance upon initial contact with the carrying gripper. Thus, the proper sliding of the weft on the front edge of the means is impeded, at the part between the fabric and the transport gripper, at the moment of initial contact with the transport gripper when the arrangement of the weft is inclined to the fabric, and such weft portion Between the moments of cutting, which are when they are substantially parallel to and thus their length decreases obviously, slip is very important to keep the weft tight.

Thus, the applicant of the present application has found that the occurrence of the above-mentioned phage irregularities is precisely due to the formation of such a loop. Indeed, depending on the mechanical response of the weft to the effect of the carrying gripper on the weft, since the loop position is completely arbitrary, the cutting moment changes forward or backward compared to the theoretical calculated, which is the basis on which the loop calculates the cutting moment. It depends on whether the wefts are arranged on the cutting means at a position that is more advanced or retracted than the theoretical straight position of the wefts.

As a result, if cutting occurs before a predetermined time, the gripping has insufficient retention strength and the transport gripper may miss the weft before reaching the weft replacement area. On the contrary, if the cutting occurs after the ideally calculated theoretical moment, the weaving proceeds with an excessive insertion of the weft yarn, which determines the holding strength of the weft yarn exceeding the tensile strength of the weft yarn, and when the weft yarn is replaced with a withdrawal gripper, It will be cut off.

It is therefore an object of the present invention to provide a gripper that solves this problem, in which the loops are formed by the weft yarns at the weft portion formed between the gripper and the woven fabric, especially in the case of very thin weft yarns. As a result, the phenomenon formed is eliminated. For this reason, the device of the present invention is referred to briefly herein as a "non-loop" device.

Another object of the present invention is to provide a gripper of the type described above to allow simultaneous processing of both thin and thicker wefts, thereby eliminating the need to replace the grippers in response to changes in the material being woven, To allow weaving.

According to the invention, these objects are achieved by a looming gripper for a loom, in which a channel is formed behind the gripper tip head so that the weft thread is inserted into the inner region of the gripper towards the elastic weft gripping means, the channel being A fabric woven on a substantially perpendicular face parallel to the direction of the waiting weft, the inlet of the resilient gripping means being arranged in a downward direction directly below the channel, the side of the inlet of the resilient gripping means being woven And a weft deflector arranged on the opposite side with respect to the weft end connected to the weft deflector, wherein the deflector tends to postpone weft entry into the gripping means.

The features and advantages of the present invention will become more apparent from the following description of the preferred embodiments of the invention.

In the gripper according to the preferred embodiment described herein, the weft deflector constituting the non-loop device of the present invention is preferably incorporated with a mobile device forming the rear wall of the weft entry channel, which device has previously been applied to the same applicant. (EP-A-1956644). This device, in addition to the function of forming the weft entry channel, allows the use of the same gripper, in particular for wefts with different counts, by allowing channel width adjustment, and at the rear of the gripper at the sliding end on the gripper tip head. It has various functions that prevent the weft slipping and thereby prevent the problem of missed weft gripping in the gripper and reduce the risk of entanglement of the gripper's body when the yarn slips on the rear of the gripper. The structure of such a device will be briefly described again below to assist in the understanding of the following description of the non-loop device of the present invention.

Known devices for forming the rear wall of the weft entry channel are clearly shown in the figures, in particular in FIGS. 2 and 3. The device consists of an elongated metal element 1, the elongated metal element 1 being formed in the rear part 1p of the element 1 which is substantially planar and parallel to the longitudinal axis of the gripper. It is fitted to the side wall of the gripper body by a screw 2 that cooperates with the eyelet; The long axis of the eyelet 3 can be parallel to the longitudinal axis of the gripper, so that the screw can be moved and the element 1 parallel to the longitudinal axis of the gripper by a distance corresponding to the length of the eyelet 3.

The front portion 1a of the element 1 is itself planar and inclined with respect to the rear portion 1p, parallel to the rear edge 4p of the gripper tip head 4. Due to this, a channel 5 of constant width is formed between the element 1 and the gripper tip head 4, which is located on a substantially vertical plane and inclined with respect to the longitudinal axis of the gripper, It is parallel to the weft yarn waiting.

In the above known structure, the non-loop device of the present invention consists of a weft deflector 6 extending longitudinally from the bottom of the weft inlet channel 5, which deflector 6 comprises elastic weft gripping means 8. Start toward the rear of the gripper in the region proximate the inlet 7 of 9). In other words, the deflector 6 is arranged such that the weft thread rests on the deflector surface as soon as the weft thread reaches the bottom of the inlet channel 5 and near the gripping means inlet 7. The weaving of the weft over the deflector 6 delays the weft entry into the gripping means, thus allowing for proper sliding of the weft at the inlet 7 during the subsequent grasping, when the weft touches the cutting means. It is completely taut in the absence of loop formation and allows it to remain properly in the gripping means 8, 9.

In the gripper of the embodiment described herein and described in the figures, the deflector 6 is integrally formed with the device 1 forming the rear wall of the weft entry channel, which constitutes the lateral extension. The ends of these extensions, which constitute a resting surface on which the weft slides on the same surface, are between 0 and 90 degrees, preferably between 50 and 80 degrees, as clearly shown in the cross-sectional view of FIG. Inclined laterally and downwardly at an angle. The deflector 6 further has an area with a wide radius connecting the deflector with the front part 1a of the device 1 at the front, providing continuous and regular support to the weft.

Thus, the degree of support provided by the deflector 6 to the weft and thus the delay when the weft is inserted into the gripping means 8, 9 simply changes the inclination to the vertical plane (the angle is 0 degrees). There is no delay and the delay is greatest when the angle is 90 degrees, i.e. when the resting surface of the deflector is substantially horizontal) smoother or less smooth the connection between the part 1a of the device 1 and the deflector 6 Can be adjusted easily.

As described above, the deflector 6 extends longitudinally at the bottom of the weft entry channel 5. More precisely, the free lower edge of the deflector 6, ie the edge at which the weft is free at the end of the "pause" operation above the deflector, is exactly at the height of the inlet 7 of the elastic gripping means 8, 9 of the weft yarn.

A remarkable advantage is achieved by manufacturing the deflector 6 integrally with the device 1, when the device 1 is moved such that the width of the weft inlet channel 5 changes, so that the non-loop device 6 also It is moved in a way that is completely suitable for its function. Indeed, since the elastic gripping means 8, 9 are fixed, when the device 1 is moved backwards to weave with a higher count of weft, the front edge of the deflector 6 is also moved so that the inlet ( It is evident that it is disposed closer to 7), so that the "resting" effect of the wefts is later seen to a limited degree. However, this precisely corresponds to the gripping requirements of the higher count wefts that must be secured to the gripper by a tighter grip action. Thus, in this case it is desirable that the delayed action of the non-loop device is weaker.

From the above description, it is clear how the non-loop apparatus of the present invention fully achieves the object of the present invention. Although the invention has been described with particular reference to the preferred embodiments of the same invention, it is intended that the protection scope of the invention be within the understanding of the person skilled in the art, for example in the form of a deflector 6 or such deflector As far as the manner of fixing to the gripper is concerned, it includes as many variations as possible.

Indeed, thanks to the presence of the deflector 6, a short delay is provided for the gripping action, which completely avoids the formation of loops in the weft portion between the gripper and the woven fabric, i.e. precisely in the region where the cutting means works. Is allowed. This ensures that the exact moment of weft cutting can be adjusted in an accurate and repeatable way, without causing premature loss of the weft by the carrying gripper, and ensuring that the weft does not break when replacing the weft with the withdrawal gripper. To provide. Furthermore, by manufacturing the deflector 6 integrally with the device 1 forming the rear wall of the weft inlet channel 5, the device 1 is moved to the size of the channel 5 according to the count of the wefts being woven. Adjustable and at the same time effective control of the "delay" effect of weft phage, which is enhanced in the case of thin weft and thick weft.

Claims (7)

It is a carrying gripper for the loom, A channel 5 is formed behind the gripper tip head 4 so that the weft yarn is inserted into the inner region of the gripper towards the elastic weft gripping means 8, 9, the channel being substantially perpendicular to the direction of the weft yarn waiting. Located on the phosphorus surface, the inlet 7 of the elastic gripping means is arranged in the direction just below the channel above the lower part of the channel 5, A weft deflector 6 arranged laterally at the inlet 7 of the resilient gripping means 8, 9 and opposite to a weft end connected to the woven fabric, said deflector 6 The transfer gripper for the loom which can delay the weft entry into the holding means (8,9). The transport gripper (10) according to claim 1, wherein the deflector (6) comprises an element fixed to or integral with the gripper, deployed longitudinally of the gripper and having a resting surface for weft yarn. 3. The conveying gripper for the loom according to claim 2, wherein the weft rest surface formed on the deflector (6) has a radius from the front to the rear wall of the weft inlet channel (5). 3. The conveying gripper for the loom according to claim 2, wherein said weft rest surface formed on said deflector (6) has a slope between 0 and 90 degrees with respect to a vertical plane. 3. The transport gripper for a loom according to claim 2, wherein said weft rest surface formed on said deflector (6) has a slope between 50 and 80 degrees with respect to a vertical plane. 3. The transport gripper according to claim 2, wherein the free lower edge of the deflector (6) is arranged on the elastic weft gripping means (8,9) at the same height as the inlet (7). 7. The gripper according to any one of the preceding claims, wherein the gripper further comprises a moving device (1) which forms the rear wall of the weft entry channel (5), wherein the multiplexer (6) comprises the device (1). The transfer gripper for the loom formed in one piece and moving together.

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