Heald shaft comprising a heald support rod

Abstract

In a heddle frame with an upper (10) and with a lower frame part (11) and with heddle bars (17, 18) attached to the frame parts, it is provided that the frame parts (10) are provided with a profiled rib (24) running in the longitudinal direction, and that the heddle bars (17) have a profiled longitudinal groove (25) gripping around the profiled rib.

Description

The invention relates to a heddle frame with at least one frame part and with at least one heddle bar attached to the frame part.

For frame parts on the one hand and heddle bars on the other hand, different materials are usually selected to cope with opposing requirements. On the one hand, the heddle frames should be as light as possible to permit high weaving speeds, while on the other hand they should be as dimensionally stable and bending-resistant as possible. The frame parts are therefore made from a lightweight material, preferably as hollow sections, in order to achieve the highest possible bending resistance. The heddle bars, which are adapted to the shape of the heddles and which are subject to wear due to the movements of the heddles, are on the other hand made from a hardest possible and wear-proof material, in particular steel. The different materials for the frame parts on the one hand and the heddle bars on the other lead to problems with the attachment of the heddle bars to the frame parts.

It is known (from U.S. Pat. No. 3,151,634) how to attach heddle bars by means of rivets or the like and further attachment means to the frame parts. Due to the different materials and the high acceleration forces occurring, these attachment elements are fault-prone, since the risk of damage is relatively high, in particular the risk of fatigue fractures.

In a known design (U.S. Pat. No 3,754,577), the frame parts are extruded sections made from an aluminium alloy. The upper frame part is provided with a downward projecting flange and the lower frame part with an upward projecting flange. Webs running in the longitudinal direction project from these flanges and form between them a receiving groove for the middle web of a T-shaped heddle bar. The middle web of the heddle bar is glued into the groove. To ensure that the adhesive is evenly distributed, the webs of the flange of the frame part are provided with projections.

The frame parts and the heddle bars are placed in a press and held so that they cannot move relative to one another when the adhesive thermally sets at around 120° C.

The object underlying the present invention is to provide a heddle frame of the type mentioned above where a simple and secure connection is provided between the frame part and the heddle bar that can be achieved without presses or gauges or the like.

This object is solved in that the frame part is provided with a profiled rib running in the longitudinal direction, and in that the heddle bars comprise a profiled longitudinal groove gripping around the profiled rib.

The profiled rib can without any difficulty be dimensioned so thick that the risk of damage is relatively low. The material of the heddle bar has a relatively greater strength, so that the longitudinal groove provided in the heddle bar does not present a major risk of damage.

In an advantageous embodiment of the invention, it is provided that the profiled rib of the frame part and the profiled longitudinal groove of the heddle bars form a positive connection transverse to the longitudinal direction. A positive connection of this type means that during assembly the frame part and the heddle bar are precisely aligned relative to one another without a press, a gauge or a template or the like being required. It is here of particular advantage here if the profiled rib of the frame part with the profiled longitudinal groove of the heddle bar forms a snap-in connection. A snap-in connection of this type permits particularly easy assembly.

In a further embodiment of the invention, it is provided that the profiled rib of the frame part is glued to the longitudinal groove of the heddle bar. The adhesive, for example a thermally setting adhesive, increases the firmness of the connection between the frame part and the heddle bar. At the same time, the adhesive compensates for play between the profiled rib and the longitudinal groove without however determining their position, which is fixed by the positive connection.

Further details and advantages of the invention are shown in the following description of embodiments shown in the drawing.

FIG. 1 shows a view of a heddle frame in accordance with the invention,

FIG. 2 shows a section along the line II-II in FIG. 1,

FIG. 3 shows a section through the profiled rib of the frame part in a larger scale,

FIG. 4 shows a section through a heddle bar that does not yet have its final form,

FIG. 5 shows a section through the heddle bar in accordance with FIG. 4 after it has received its final form,

FIG. 6 shows a partial section similar to FIG. 2 in a larger scale,

FIG. 7 shows a partial section similar to FIG. 6 with an additional cushioning strip, and

FIG. 8 shows a partial section through an embodiment for heddles with J-shaped eyelets.

A heddle frame as shown in FIG. 1 has a frame made up of an upper frame part 10, a lower frame part 11 and side parts 13, 14 that connect the former two. The upper and lower frame parts 10, 11 have downward and upward facing flanges 15, 16 respectively, to which are attached heddle bars 17, 18. The heddle bars 17, 18 accommodate eyelets 19, 20 of heddles 21 that are provided between the eyelets with a thread eye 22 through which warp threads run.

Due to the high weaving speeds usual today, the intention is for such heddle frames to be on the one hand as light as possible and on the other hand to be as bending-resistant or deformation-resistant as possible. Since the eyelets 19, 20 on the heddle bars 17, 18 are guided with play for handling reasons, the heddle bars 17, 18 must comprise a material as wear-proof as possible. In practice, the frame parts 10, 11 are preferably made from extruded light metal sections, i.e. sections of aluminium or of aluminium alloy. As can be seen from FIG. 2, in the embodiment the frame parts comprise a flat and rectangular cross-section of which the main extent is in the direction of movement, i.e. in the vertical direction. In the embodiment, the frame parts 10 have four hollow chambers which if necessary can also be filled with stiffener inserts or cushioning inserts or the like. A flange 23 provided with a profiled rib 24 projects downwards from the upper frame part 10. A heddle bar 17 is mounted on this profiled rib 24 and is a flat strip provided with a profiled longitudinal groove gripping around the profiled rib 24. The profiled rib 24, which has an end area 26 tapering outwards in dovetail form, is shown to larger scale in FIG. 3.

The heddle bar 17 is an extruded steel section initially extruded in the form as shown in FIG. 4. It first has a longitudinal groove 25′ rectangular in cross-section, the side flanks of which are extended by means of longitudinal ribs 27, 28 projecting beyond the contour of the strip which is flat per se. These longitudinal ribs 27, 28 then undergo plastic deformation by cold-rolling such that they are inside the outer contour, the result being a straight and smooth outside. The longitudinal ribs 27, 28 are now pressed into the previously rectangular longitudinal groove 25′ such that the longitudinal groove 25 undercut in dovetail form is obtained, as shown in FIG. 5. As can be seen from FIGS. 4 and 5, the longitudinal rib 28 is somewhat smaller in cross-section than the longitudinal rib 27. The result is, in the area where the longitudinal rib 27 was located previously, a groove flank 29 that forms with the bottom of the longitudinal groove 25 a smaller angle than that formed by the groove flank 30 rolled from the longitudinal rib 28. Since the bottom of the longitudinal groove 25 is somewhat wider than the outer end of the dovetail-like part 26 of the profiled rib, the heddle bar 17 can be hooked over and then pressed onto the profiled rib 24 with its groove flank 29, with the groove flank 30 engaging with (snapping onto) the profiled rib.

To make the connection between the heddle bar 17 and the frame part 10 even more secure and above all to rule out any play and hence noise, an adhesive, for example a thermally setting adhesive, is applied into the longitudinal groove 25 before clipping on of the heddle bar 17. Even if this adhesive loses its adhesive effect over the course of time, it retains its function of compensating for play while it is still present. The loss of adhesive effect over time can be advantageous for removal of the heddle bar 17. For that reason an adhesive can be purposely used that loses its adhesive effect after a given time.

In a modified embodiment, it is provided that the undercut longitudinal groove 25 is machined into the section of the heddle bar 17 by milling or slotting or the like.

The lower frame part 11 has the same cross-section as the upper frame part and is arranged mirror-symmetrically thereto, i.e. the flange 23 of the upper frame part 10 is opposite the matching flange of the lower frame part. The heddle bar 18 has a form corresponding to heddle bar 17 and is attached in the same way. It is provided here that the groove flank 29 forming a narrower angle is at the bottom, i.e. the heddle bar 18 is mirror-symmetrical to heddle bar 17.

In a modified embodiment, it is provided that the profiled rib 24 is not designed solid, but has a hollow chamber running in the longitudinal direction. In a further modified embodiment, the heddle bars 17, 18 are not clipped onto the profiled ribs 24, but slid on in the longitudinal direction. In this embodiment it can then be provided that the play between the profiled surface of the profiled rib 24 and the profiled longitudinal groove 25 is relatively small.

The application of an adhesive can be achieved by coating the outer surface of the profiled rib 24 and/or the inner surface of the profiled groove 25 with an adhesive before connecting the profiled rib 24 and the profiled longitudinal groove 25. In a modified embodiment, it is provided that the heddle bars 17, 18 are provided with holes at a distance to one another and open to the bottom of the longitudinal groove 25. An adhesive can then be applied under pressure through the holes to the opposite surfaces of the profiled rib 24 and the longitudinal groove 25 after assembly.

With the embodiments according to FIGS. 6 to 8, it is provided that the flange 23′ of the frame part 10 is provided with a profiled rib 24′ that is wider than the end face with dovetail-like profile. The eyelets 19 of the heddles 21 are designed C-shaped and grip around the heddle bar 17 both upwards and downwards. In the embodiment according to FIG. 6, the heddles 21 are drawn along by the heddle bars 17 and 18 during raising and lowering of the heddle frame. In the embodiment according to FIG. 7, a cushioning strip 31 made of plastic or the like is provided that is opposite the ends of the eyelets 19 of the heddles 21. The heddle bars 17, 18 and the eyelets 19 are dimensioned such that when a heddle frame is raised or lowered, the ends of the eyelets 19 of the heddles 21 contact the cushioning strip 31 of the upper frame part 10 or of the lower frame part 11 respectively. In this case, the heddle bars 17, 18 only have the task of guiding the heddles transversely to the movement of the heddle frame. They can then also be made of aluminium or of an aluminium alloy.

With the embodiment according to FIG. 8, J-shaped eyelets 19′ are provided for the heddles 21. The heddle bars 17′ are designed to correspond to these eyelets, i.e. they extend from the longitudinal groove 25′ only to one side, i.e. to the associated frame part.

The invention is not limited to the embodiments shown. Changes can be made in particular with regard to the design of the eyelets 19 of the heddles 21 and hence also the form of the heddle bars 17, 18. The same applies for the form and the arrangement of the strip-like cushioning element 31. Materials other than aluminium or aluminium alloys can also be used for the upper and lower frame parts 10, 11, in particular fibre reinforced plastic material, such as for example plastic material reinforced by carbon fibres or Kevlar fibres. Other materials are also possible for the heddles bars 17, 18, in particular high-strength and low-wear plastics. The invention is also suitable for heddle frames having only one frame part 10 or 11 with a heddle bar 17 or 18 attached thereto.

Claims

1. Heddle frame comprising at least one frame part extending in a longitudinal direction, and including at least one heddle bar attached to the frame part, said frame part being is provided with a profiled rib running in the longitudinal direction, and wherein the heddle bar comprises a profiled longitudinal groove engaging the profiled rib.

2. Heddle frame according to claim 1, wherein the profiled rib of the frame part and the profiled longitudinal groove of the heddle bar form a positive connection transverse to the longitudinal direction.

3. Heddle frame according to claim 1, wherein the profiled rib of the frame part forms a snap-in connection with the profiled longitudinal groove of the heddle bar.

4. Heddle frame according to claim 1, wherein the profiled longitudinal groove is undercut and the profiled rib has a cross-section adapted thereto.

5. Heddle frame according to claim 4, wherein connection between profiled rib and profiled longitudinal groove is configured in dovetail form.

6. Heddle frame according to claim 1, wherein the frame part is an extruded section.

7. Heddle frame according to claim 1, wherein the heddle bar (17, 18) is an extruded section of steel.

8. Heddle frame according to claim 7, wherein the extruded section is post-treated by cold-rolling.

9. Heddle frame according to claim 7, wherein the section of the heddle bar is provided with ribs on both sides of a substantially rectangular longitudinal groove.

10. Heddle frame according to claim 9, wherein one of the ribs has a smaller cross-section than the other rib.

11. Heddle frame according to claim 1, wherein the profiled rib of the frame part is affixed to the longitudinal groove of the heddle bar.

12. Heddle frame according to claim 1, wherein the frame part comprises a first material and the heddle bar attached thereto comprises a second material.

13. Heddle frame according to claim 1, comprising an upper frame part and a lower frame part to which the heddle bar is attached.