Patent Publication Number: US-6213162-B1

Title: Weaving heddle having end eyes formed by pressing

Description:
BACKGROUND OF THE INVENTION 
     This invention relates a weaving heddle made of a strip material and a process for making the heddle. The invention relates more particularly to the formation of the heddle end eyes which, as known, permit the heddles to be lined up and hung in heddle frames. 
     It is known that weaving heddles have been used for many years in many weaving mills and it is not surprising that certain limits in efficiency have been reached. Since the cross-sectional dimensions of the metal strip used in making the weaving heddle have essentially remained unchanged, the cost of polishing remains low. Moreover unhardened steel strip material has been utilized in most cases. Both such factors allow for the production of a low cost heddle but also one which is not particularly efficient. Even with the great advancements in the weaving technology, such heddles are still used in very modern facilities because the mechanical life-span of the heddles is about the same as the limited useful life of the thread eyelet. The thread eyelet may however become damaged by modern synthetic fibers quite quickly to a degree that weaving is not made possible. Even more expensive materials such as hardened steel do not produce in most cases improved conditions in proportion to the higher expense. Thus there is a great deal of interest in the textile industry for a more efficient design of the traditional type of heddle. 
     Such heddles as they are currently used in great numbers, are generally disclosed in detail in U.S. Pat. No. 748,713. The end eyes as therein described are made by punching out an elongated rectangular opening from the strip. Thereafter the narrow sides of the opening are squeezed-pressed resulting in the longitudinal sides being deformed and the opening being enlarged. One disadvantage is the formation of wedge-shaped pressed areas at the narrow sides of the opening. These make contact with the heddle slide bar that runs through the openings such that these areas become damaged quite quickly thereby rendering the heddles unserviceable. 
     German patent 180525 discloses an improvement over the U.S. Pat. No. 748,713 in the formation of heddle end eyes by first deforming the area of the end eye by squeeze-pressing it into the desired width and then punching out the weakened sections so formed. It appears that a substantially strengthened end eye is produced by the removal of the thin pressed sections. However, formation of the end eyes according to such a method can be realized with only a very soft original material which diminishes the overall advantages offered by the end formation technique. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a weaving heddle having end eyes formed in a manner which improves upon that of German 180525 and which the strip of material from which the heddle is made is substantially stronger to thereby meet the requirements of modern day weaving mills. 
     In accordance with the invention a weaving heddle is made of an elongated strip of material having squeeze-pressed and punched out end sections forming end eyes adjacent the terminal ends of the strip. Each of the end eyes is defined by a pair of spaced apart side legs lying parallel to the longitudinal axis of the strip. The side legs have outer edges extending laterally outwardly of opposed outer edges of the remainder of the strip. And at least one of the opposing faces of the strip has at least one deformation defining an indentation adjacent one end of each of the end eyes. 
     In the production of the weaving heddle according to the invention, there is provided at first a squeeze-pressed section oriented in a longitudinal direction in the area of the end eye to be formed, and preferably lying along the longitudinal axis of the strip such that the strip is widened in the area of the end eye to be formed, and the end eye is formed by subsequently punching out the strip material at the squeeze-pressed section. An additional squeeze-pressed section is applied simultaneously at a distance from a short end of the eye to be formed, and preferably additional pressed sections are formed at distances from both short sides of the eyes to be formed. Thus three squeeze-pressed sections are formed in the area of end eye to be formed. When such squeeze-pressed sections are formed simultaneously, each end eye is subsequently formed by punching out the squeezed material from that pressed section of the eye to be formed. 
     Between the three pressed sections, there remain two narrow ridges for areas that are undeformed. The two auxiliary pressed sections adjacent the short ends of the end eye as formed function to extend the area from the widest section of the deformed end eye to the non-deformed strip to thereby minimize the development of any stresses in the material. In other words the auxiliary pressed sections which form deformations provide for elongated and smoother transitions between the widened section of the strip from which the end eye is formed, and the undeformed portions of the strip. Moreover the two auxiliary pressed sections may be shaped in such a manner that the ridges are slightly puffed so that the thickness, even with the widening of the strip in this area, correspond approximately with the thickness of remaining strip. The end eyes are formed by punching out the middle squeeze-pressed section, the punched areas overlapping the slightly pushed-up ridges so that a large bearing surface for the heddle slide bar is formed. This relatively large bearing surface prevents premature material wear. Thus in addition to using strip material with increased stability, the heddle produced according to the invention meets stress requirements found in the modern day weaving mills. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective longitudinal view of a heddle formed according to the invention as shown hanging on the heddle slide bars of a weaving frame; 
     FIG. 2 is a plan view of a typical end section of the weaving heddle of FIG. 1; 
     FIG. 3 is a cross-sectional view taken substantially along the line A—A of FIG. 2; 
     FIG. 4 is a cross-sectional view similar to FIG. 3 after the deformed portion forming the end eye has been punched out; and 
     FIG. 5 is an enlarged view similar to that of FIG. 2 illustrating the complete punched out end eye of the heddle. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows heddle  1  formed according to the invention as it is lined up on the heddle slide bars  4 ,  4 ′ of a weaving heddle frame not otherwise shown. The heddle has a typical central thread eyelet  2  and end eyes  3 ,  3 ′ at opposing end portions of the heddle. A warp thread  5  is shown guided through thread eyelet  2  as in the normal and known manner. 
     A typical end section of heddle  1  is shown in FIG. 2 as having a middle pressed section  6  and two auxiliary pressed sections  7 ,  7 ′ formed at spaced distances from the short sides of the rectangularly shaped middle pressed section  6 . The auxiliary pressed sections  7 ,  7 ′ respectively form ridges  8 ,  8 ′ which are not squeeze-pressed but are slightly pushed up. Middle pressed section  6  is formed by pressing together, as by cold forming, localized areas at opposing faces of the strip of material from which the heddle is formed or initially forming opposed elongated indentations lying along the longitudinal axis of the heddle/strip as shown. The auxiliary pressed sections  7 ,  7 ′ are formed respectively adjacent the short sides of the heddle pressed section  6  by applying deformations to at least one of the opposing faces of the strip to define indentations as shown adjacent at least one end of each end eye. 
     As clearly seen in FIG. 2, the strip of material of heddle  1  is widened by the formation of the middle pressed section  6  in the area of the future end eye opening. Even with a widening effected by squeeze-pressing, the opposed pair of legs oriented along the sides of the middle pressed section  6  are at an unreduced thickness relative to the thickness of the remainder of the strip of material of the heddle, as clearly shown in FIG.  3 . 
     Clearly visible in FIG. 3 are the central pressed section  6  forming indentations at opposing sides of the strip for the formation of the future end eye openings, as well as the auxiliary pressed sections  7 ,  7 ′ which likewise form indentations in opposing faces of the strip. And it can be seen that the auxiliary pressed sections  7 ,  7 ′ are shaped in such a manner that in the longitudinal direction displaced material of ridges  8 ,  8 ′ so formed are slightly pushed up relative to the non-deformed strip material. 
     In FIG. 4 the middle squeeze-pressed section  6  has been shown punched out to remove the middle squeeze-pressed portion together with adjoining portions of ridges  8 ,  8 ′, as shown, thus providing large bearing surfaces for the heddle slide bear which tend to prevent premature material wear. Also it can be seen that the auxiliary squeeze-pressed sections  7 ,  7 ′ are not punched out and that the thickness of ridges  8 ,  8 ′ remain substantially the same as the thickness of the non-deformed remainder of the strip material. However, ridges  8 ,  8 ′ may be so formed that their thickness is slightly greater than the thickness of the non-deformed remainder of strip material. 
     FIG. 5 illustrates the completed end eye section at an end of the heddle which is typical for the opposite end as well. It can be seen that by forming the two auxiliary pressed together sections  7 ,  7 ′ the transition area of the widened strip in the area of the end eye relative to the non-deformed strip section of the heddle remains relatively straight and whereby the transition area is additionally strengthened by forming the two ridges  8 ,  8 ′. In contrast to the state-of-the-art of known designs of end eyes with widened strips, the innovative design of the strip material according to the invention leads to increased stability such that a heddle is formed that meets the stress requirements found in modern day weaving mills. 
     The formation of each end eye with corresponding squeeze-pressed auxiliary sections shown in FIGS. 1 to  5  is of course only an example to permit a better understanding of the present invention. It also possible for example, to provide an auxiliary pressed section  7 ,  7 ′ adjacent only one of the short sides of the middle pressed section of the eye to be formed. And it is possible to provide the auxiliary pressed section or sections  7 ,  7 ′ to form an indentation at only one of the opposing faces of the strip from which the heddle is formed, without departing from the invention. Also the method of providing the squeeze-pressed sections is not critical to the invention but maybe carried out by cold forming. 
     The strip of material from which the heddle is made may comprise thermally hardened steel. The strip may otherwise comprise super hardened steel formed by cold forming. 
     Obviously many other modifications and variations of the present invention are made possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.