Heddle Frame Assembly Construction and Method

This invention relates to heddle frames for weaving looms and more particularly to improvements in their construction in the attachment of heddle supporting rods to the heddle frames.

Heretofore, it has been common in the weaving art to employ heddle frames having rods on which the heddles are mounted. These rods are typically made of steel strips with a cross-section which facilitates mounting on the frame and on which the end eyes of the heddles are freely movable. An illustration of such heddle rods is in U.S. Pat. Nos. 3,417,788 and 4,106,529. These patents show the heddle rods being riveted at their faces to the heddle frame slats and joined at their end to the side struts of the heddle frame.

During shedding operations on a weaving loom, the heddle frame reciprocates vertically in rather short, rapid strokes with the warp yarns threaded through the center eye of the heddle. The warps are thus lifted up and down. The dynamic forces on the heddle frames and their assembly parts are large during the shedding motions. With the advent of high speed looms, such as water-jet looms, the vertical reciprocation of the heddle frame occurs at even higher speeds resulting in even larger accelerations and dynamic forces on the heddle frame. Thus, the parts and connections in the heddle frame assembly are subjected to larger stress and fatigue forces than ever encountered in shuttle looms. This has required more reliable and accurate construction of the heddle frame assembly to eliminate weak spots.

In particular, the heddle rods have been, heretofore, riveted to the slats of the heddle frame by conventional methods in which a countersink opening is formed in the face of the heddle rod and the corresponding surface of the heddle frame slat against which the rod mates. A rivet is peened or headed on both ends within the countersink openings to form a conventional rivet connection between the members. However, inaccuracies in the heddle rod thickness and rivet countersink dimensions make this type of connection susceptible to failure. These dimensions are critical since the rivet is of a fixed length and amount. If any of these dimensions are beyond acceptable tolerances, the rivet material either fills the opening too much or too little. If the countersink opening is too small, excess rivet material forms a protruding rivet head which impairs free heddle travel over the face of the rod. If the opening is too deep, the rivet material either does not fill the opening completely or too much rivet material is used in the opening leaving an insufficient amount in the other opening resulting in an imperfect rivet head and weak connection.

Furthermore, even a properly headed rivet connection allows wobbling of the heddle rod about the connection which, after prolonged use, can become attenuated and lead to failure. The end eyes of the heddles often engage the rivet head exposed on the face of the heddle rod causing excess wear therebetween which leads to loosening of the rivet head.

Typically, the rivet must be held with a serrated anvil to prevent the rivet from turning during peening which can cause improper heading. However, deterioration of the serrated anvil also reduces the integrity of the rivet head connection.

Accordingly, an important object of the invention is to provide a heddle frame assembly having increased long-term dependability for use on high-speed shuttleless looms.

Another important object of the present invention is to provide a heddle frame wherein the heddle rod is provided with a smooth, unbroken face ensuring free travel of the heddles and reduced wear.

Another important object of the present invention is to provide a heddle frame assembly and method which eliminates inaccuracy in the riveting process and results in more accurate heddle frame construction which results in fewer rejects and less scrap.

Yet another important object of the present invention is to reduce the steps and inaccurracies involved in the manufacturing and assembling of heddle frames due to the elimination of piercing and countersinking of rivet holes.

Still another important object of the present invention is to provide a more stable and rigid connection between the heddle rod and heddle frame slats of the heddle frame assembly which reduces wobbling therebetween.

In accordance with the present invention the above objectives are accomplished by providing a rivet stud which is welded to the heddle rod to form an integral counstruction and stud of accurate dimension for insertion into a countersink opening in the heddle frame slat which is then riveted therein and which thus eliminates the presence of a countersink opening and rivet head in the heddle rod face and reduces the possibility of dimensioning variances.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing forming a part thereof, wherein an example of the invention is shown and wherein:

FIG. 1 is a front elevation illustrating a heddle frame assembly constructed according to the present invention,

FIG. 2 is a sectional view taken along line 2--2 of FIG. 1,

FIG. 3 is a side elevational view illustrating a heddle rod and weld-rivet stud utilized according to the invention,

FIG. 3a is a side elevational view illustrating the heddle rod and rivet stud of FIG. 3 in a welded integral construction for unitary attachment to a countersink formed in the associated heddle frame slat according to the invention as seen in FIG. 2.

FIG. 4 is a perspective view illustrating the assembly of a heddle rod and heddle frame slat according to the invention,

FIG. 5 is a perspective view illustrating a construction of the smooth, unbroken face of a heddle rod according to the invention,

FIG. 6 is a perspective view illustrating the face of a riveted heddle rod constructed according to the prior art, and

FIG. 7 is a side sectional view of the riveted construction of the prior art heddle rod and heddle frame assembly of FIG. 6.

The invention relates to a method and construction for a heddle frame assembly of the type having top and bottom frame slats which support heddle rods on which end eyes of the heddles are slidably carried. Since the operation of heddle frames and weaving looms is well known in the art, only that portion of the heddle frame assembly necessary to understanding of the invention will be illustrated.

FIG. 1 illustrates a heddle frame A having an upper heddle frame slat 10 and a lower heddle frame slat 12. The upper and lower slats are joined together by side struts 14 and 16. The frame slats 10 and 12 are preferably of an extruded tubular aluminum construction. The frame slats 10 and 12 are identical and, for example, slat 12 includes a tubular portion 12a and an extended neck portion 12b on which a ledge portion 18 is carried extending outwardly to provide a space for the end eyes of the heddles H to fit over heddle rods 20 and 22.

According to the invention, the heddle rods 20, 22 are attached to the respective frame slats in an identical manner which includes providing studs 24 which are welded to the heddle rods, such as 20, at spaced intervals along the length. Corresponding countersink openings 28 are spaced and formed in the ledge means 18 along the width of neck portion 12b of the heddle frame slat 12. As illustrated, studs 24 are in the form of a weld-rivet stud having a pointed projection 26 at one end consisting of metal which can be welded by conventional capacitor discharge welding techniques to the heddle rod. When rivet studs 24 are integrally welded to the heddle rod 20, a weld pocket 26a is formed in the rod back surface by molten metal 26 which makes the stud 24 and rod 20 integral and unitary as one piece. The opposing end of the stud 24 is suitable for peening to make a rivet head. In this manner, the effective length of the stud as a rivet connection is maintained since no stud material is consumed in the weld joint nor is any material left standing between the end of the stud and rod back surface to alter this length which projects in the countersink openings 28 assuring a reliable dimension and uniform filling thereof to provide a proper rivet head. The stud is preferably stainless steel to reduce corrosion when used on a water-jet loom. Typically 20 of such studs are spaced across the rod.

The heddle rod is attached to the neck 12b of the frame slat by placing the studs 24 in the corresponding opening 28. Next, the ends of the studs 24 are peened and headed to form a rivet head at 24a which rivets the rod securely to the neck of the frame slat. Thus, assuming studs 24 to be of standard length, only the thickness through the ledge 18 and the dimension of countersink 28 need be accurately determined to assure a proper rivet heading and connection so as to eliminate weak points.

The elimination of a countersink and rivet head on the face of rod 32 eliminates a source of dimension variation as occurs in prior art FIGS. 6 and 7 wherein a countersink is required in the face of rod 32. The step of polishing and deburring the face 32 is eliminated.

The face of the rod 20 over which the heddle H travels is smooth and unobstructed so as to insure free travel of the heddles. A more rigid frame assembly is provided which virtually eliminates wobbling of the rod due to large forces or a loose connection between a rivet head 30 and heddle rod 32 as in the prior art construction. Furthermore, turning of the rivet is eliminated during the peening operation without use of a serrated anvil.

Most important, however, is that it has been found that this assembly and method for a heddle frame construction results in a more accurtely dimensioned and constructed frame wherein the connections between the heddle support rod and frame slat are more uniform in strength. Continued performance on high speed, shuttleless looms tends to bring out the presence of a weak rivet connection resulting in failure of that connection which is substantially eliminated herein.

While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.