LEO EDGE DEVICE FOR FORMING A LEO EDGE

Abstract

The subject matter of the invention relates to a leno selvedge device (1) for forming a leno selvedge with two opposing lifting healds (10) which can be arranged on two alternately moved heald frames of a weaving machine, and wherein the lifting healds (10) have a foot (11) for connection to a heald support rail, wherein a half-heald (12) made of a metallic flat material is received between the lifting healds (10), said half-heald having two legs (13) which are connected to one another via a half-heald head (14), and wherein a respective stopper (15) is received on the legs (13) of the half-heald (12) in order to abut against the foot (11) of the lifting healds (10) during the lifting movement thereof, wherein a recess (16) is made in the leg (13) into which the stopper (15) is inserted. According to the invention, the recess (16) in the leg (13) has a contour which forms at least one holding geometry (17) for holding the stopper (15).

Description

The invention relates to a leno edge device for forming a leno edge with two lever pins which are located opposite each other and which are arranged on two mutually stroke-movable heald shafts of a weaving machine. The lever teats each have a foot for connection to the heddle support rails, and a half-heddle made of a metallic flat material is accommodated between the lever teats carrying out the lifting movement in the opposite direction. The half-stranded wire has two legs which are connected to one another via a half-stranded wire head, and wherein a respective stopper is received on the legs of the half-stranded wire in order to abut against its foot during the lifting movement of the lever point, and wherein a recess is made in the leg, in which recess the stopper is inserted.PRIOR ARTLeno edge devices serve to form a leno edge and essentially consist of two lever pins which are arranged on two mutually stroke-moved heald shafts of a weaving machine, so-called heddle support rails serving to receive the lever pins. A leno edge device serves to form a leno edge, for which a half-strand is arranged between the two lever teats, which half-strand is taken along alternately by the lever teats according to the lifting movement of the heald shafts. The half-braid is substantially constructed from two legs which converge at their upper end with an eyelet for guiding the so-called stayed thread, forming a half-braid head. Such a half-strand is usually produced from a metallic sheet metal material, for example by a laser cutting or a punching process. Each lifting strand has at its lower end a magnet which effects a controlled entrainment of the half strand by the respective lifting strand in such a way that the magnetic force ensures that the half strand is held by the lifting strand during the respective entrainment movement by the lifting strand.This principle is known, for example, from EP 0 916 758 B1 or from DE 38 18 680 C1. The half-strand is carried along by the lifting strand and here in particular by a web arranged in the lifting strand, on which web the half-strand rests with its end-side head during the carry-along by the respective lifting strand.A first thread is guided through the eyelet in the half-braid head, while a second thread alternately migrates to the left or to the right of the first thread. According to this principle, the edge threads can be twisted together during the production of a woven product.In weaving machines, up to 1,200 wefts per minute can be moved, which quickly leads to the lifting strand cutting in the region of its web. In particular, when the half-stranded wire strikes the web more strongly with its periodic lifting movement, wear phenomena result. In order to avoid such cutting, it is known to attach a stopper to the underside of the legs of the half-strand. For the stopper, which is made of a plastic, a recess is provided in the leg into which the stopper can be inserted. Due to the dynamic movement of the half-strand and the periodic striking of the half-strand on the associated stops on the lever studs, a reliable function of the stops is ensured only if these stops are also arranged captive in the recess in the leg of the half-strand.DISCLOSURE OF THE INVENTIONThe object of the invention is to further improve a rotary edge device which in particular allows longer service lives and experiences less wear.This object is achieved on the basis of a rotary edge device according to the preamble of claim 1 in conjunction with the characterizing features. Advantageous further developments of the invention are specified in the dependent claims.The invention includes the technical teaching that the recess in the leg has a contour which forms at least one holding geometry for holding the stopper.The basic idea of the invention is an expansion of the recess in the leg with a contour comprising a holding geometry in order to prevent the stopper from being lost from the recess. The holding geometry has in particular a form-fit contour in the recess, by means of which the stopper made of a plastic is held captive in the recess and thus on the leg of the half-strand.The recess has a U-shape with particular advantage, comprising two opposing holding edges and a base edge. In other words, the recess forms a quadrangular indentation in the outer contour of the leg of the half-strand into which the stopper is inserted. Since the stopper is made of a resilient plastic material, the form fit can be overcome by the resilient fit, for example by a region of the stopper snapping into an undercut in the holding edge after its elastic deformation. For example, the holding geometry can be produced by forming undercuts in both holding edges, which undercuts are configured, for example, in the shape of a tooth or hook. The undercut can, for example, point like a saw-tooth contour in the direction of the base edge, so that when a stopper is pressed into the recess once the latter can no longer be lost from the recess alone. In particular, the at least one undercut or the plurality of undercuts can preferably be introduced in both mutually opposite retaining edges of the U-shaped cutout. The undercut can form a notch in the retaining edge, which is designed like a barb, with an active direction which points towards the base edge of the recess and holds the stopper in the recess. In particular, when the stopper as a result of the lifting movement of the lever pins and also of the half-strand itself regularly strikes the stop on the foot of the lifting strand, a form-fit geometry acts in the contact edge on the stopper, which is possible both with a notch in the retaining edge and with a tooth-shaped or wedge-shaped formation on the retaining edge.It can also be provided that holding protrusions are formed on the stopper itself, which in particular are formed complementary to the notches that are present in the holding edge. Thus, when the stopper is inserted into the recess, the retaining lugs can engage in the notch.The cutout can be embodied symmetrically, so that on both sides of a line of symmetry the cutout has a mirror-image contour; in particular, the two holding edges on both sides of the line of symmetry can be embodied identically to one another, in this respect therefore extend and are contoured mirror-image to the line of symmetry. The line of symmetry represents the joining axis, from which the stopper is guided into the recess and locked therein. In general, the invention is directed to the basic idea of configuring the holding geometry such that the stopper can engage or engage in the recess in order to be held in a self-holding manner in the recess.It is thus furthermore conceivable for the two opposite holding edges to be formed so as to extend at an angle to one another and to diverge towards the base edge. The holding edges themselves can thus form the undercut geometry, so that a stopper, once pressed in, is introduced in the recess in a self-holding manner and with a geometric form fit. Indentations or tooth-shaped formations on the holding edges can additionally be provided. Thus, the undercut geometry can produce a macroscopic holding effect via the beveled holding edges, and notches or depressions in or on the holding edges can form microscopic holding means in a superimposing manner, so that the stopper is held in the recess based on multiple holding effects.Alternatively, however, it can also be provided that the two mutually opposite holding edges are designed to extend towards one another at an angle to the base edge. This produces the effect that the recess is formed in a somewhat wedge-shaped manner via the obliquely running holding edge, and the stopper can be pressed into the wedge geometry, and by the operation of the rotary edge device, in which the stopper is pressed increasingly further into the wedge-shaped recess by regular impact on the stop at the foot of the lifting cable, in order thereby to achieve a clamping effect. Overlapping this configuration of the holding edges with respect to one another, notches can be introduced in the holding edge or add-ons can be applied to the latter in order to achieve a positive fit via the holding edge itself.The stopper can also have lateral slots into which the retaining edges are inserted in a tongue and groove arrangement. It is also conceivable that the stopper has an oversized dimension relative to the recess, in particular so that the stopper is pressed into the recess with a slight joining force. It is advantageous if the stopper is formed from a plastic material, for example from a polyamide.The legs of the half-strand may extend along a lifting axis, wherein the line of symmetry of the recess extends at an angle to the lifting axis of 20° to 60°, preferably 30° to 50° and particularly preferably 40°. The stop on the top of the foot of the lifting braid may be slightly tapered to avoid the accumulation of lint. In particular, due to the beveled arrangement of the stopper via the line of symmetry set at an angle to the lifting axis and thus the mounting axis of the stopper, the stopper ensures that contaminants, in particular lint, do not accumulate in the groove of the stop on the upper side of the foot of the lifting cable.PREFERRED EMBODIMENTS OF THE INVENTIONFurther measures which improve the invention are described in more detail below together with the description of a preferred exemplary embodiment of the invention on the basis of the figures. It shows: FIG. 1 shows a rotary edge device with two lever pins and a half-strand arranged between the two lever pins, FIG. 2 shows the rotary edge device according to FIG. 1 in an exploded illustration, FIG. 3 shows a detailed view of the arrangement of the stoppers at the lower ends of the legs of the half-strand and the two lever teats, wherein the left lifting strand is in an upper and the right lifting strand is in a lower lifting position, FIG. 4 shows a first exemplary embodiment of the holding geometry based on notches in the holding edge, FIG. 5 shows a further exemplary embodiment of the holding geometry with holding projections at the end of the holding edges, FIG. 6 shows an embodiment with retaining edges running obliquely to one another, which diverge towards the base edge of the recess, FIG. 7 shows an embodiment with obliquely extending retaining edges which run towards one another towards the base edge of the recess, and FIG. 8 is a cross-sectional view of the stopper arranged in the recess on the half-strand.FIG. 1 shows a leno edge device 1 in a joined state with the threads 26 and 27, while in FIG. 2 the leno edge device 1 is shown in an exploded illustration without the threads, wherein FIGS. 1 and 2 are described together below. FIG. 1 shows the first thread 26 which passes through an eyelet in the half-strand head 14 and forms the so-called stay thread, while the second thread 27 runs as a twisting thread along the half-strand 12.The rotary edge device 1 has two lever pins 10 which are located opposite one another and which can be arranged in a manner not shown in detail on two heald shafts of a weaving machine which alternately execute a lifting movement. The lever teats 10 have a foot 11 for connection to a respective cable support rail, and a half-cable 12 made of a metallic flat material is located between the two lever teats. In contrast, the lever teats themselves can have a combination of a metallic flat material and a plastic injection-molded material.The half-braid consists of two parallel limbs 13 which are connected to one another at the top by means of the half-braid head 14. On the underside of the two legs 13 of the half-strand 12, there is a respective stopper 15 in order to abut with them, during the lifting movement of the lever teats 10, against a foot 11 which adjoins the lever teats 10 on the underside. On the upper sides of the feet 11 of the lever teats 10 there are stops 28 against which the stoppers 15 on the lower side of the legs 13 come to bear alternately when the periodic lifting movement of the two lever teats 10 is carried out. Thus, the half-strand 12 is also raised alternately with the lifting movement of the lifting strand 10.FIG. 3 shows in detail the lower ends of the two legs 13 of the half-strand 12, wherein the lever teats 10 are also shown. The left lifting strand 10 is in an upper lifting position, while the right lifting strand 10 is shown in a lower lifting position. The lifting movement can take place along a lifting axis 24, which is indicated for both lever pins 10.The two stoppers 15 are located at the lower end of the legs 13, wherein the stopper 15 is shown in its arrangement only on the first lifting strand 10, shown on the left side, while a recess 16 is shown on the right leg 13, into which a stopper 15 is not inserted. The left stopper 15 abuts the stop 28 of the foot 11 of the lifting cable 10, wherein the line of symmetry 23 of the recess 16 is shown on the right side, to which the contour of the recess is formed identically on both sides of the line of symmetry 23.The recess 16 has two opposite holding edges 18 and a base edge 19, so that the recess 16 is substantially U-shaped. The line of symmetry 23 and thus also the course of the recess 16 is designed to be beveled with respect to the stroke axis 24, for example at an angle of 40°.FIG. 4 now shows a detailed view of the recess 16 with a holding geometry 17 shown by way of example. The holding geometry 17 is formed by mutually opposite notches 21 in the holding edges 18 of the recess 16, which in each case form undercuts 20. On the other hand, holding protrusions 22 are formed on the stopper 15, and if the stopper 15 is pressed into the recess 16, the holding protrusions 22 on the stopper 15 latch into the notches 21 of the recess 16. The stopper 15 can thus be attached to the leg 13 in a captive manner.FIG. 5 shows an alternative exemplary embodiment for the self-retaining arrangement of the stopper 15 in the cutout 16, wherein the cutout 16 has in each case opposite retaining projections 29 in the transition to the outer contour of the limb 13, which likewise in each case form undercuts 20. If the stopper 15 is now pressed into the recess 16, the holding projections 29 ensure that the stopper 15 cannot fall out of the recess 16, i.e. it is accommodated in a self-holding manner in the recess 16.FIG. 6 shows an exemplary embodiment according to which the two holding edges 18 of the recess 16 on the leg 13 are beveled at an angle to one another, so that the opposing holding edges 18 diverge toward the base edge 19 of the recess 16. If the stopper 15 is pressed into the recess 16, elastic deformation of the stopper 15 must be overcome when the stopper 15 is pressed into the recess 16, in particular if the mouth opening of the recess 16 is made narrower than the receiving width of the stopper 15.FIG. 7 shows an alternative embodiment with beveled holding edges 18 which are contoured such that they run towards each other towards the base edge 19 of the recess 16. According to this holding geometry 17, a wedge effect is used, so that during operation of the rotary edge device and due to the regular abutment of the stopper 15 against the abutment on the foot of the lifting cable, the stopper 15 is pressed into the wedge-shaped recess and held by it. This presupposes an elastic deformation of the stopper 15, wherein in a manner not shown in more detail, a notch 21 with associated retaining lugs 22 according to the exemplary embodiment in FIG. 4 or with the retaining projections 29 according to the exemplary embodiment in FIG. 5 can also be combined with the geometric configuration of the retaining edges 18 of the recess 16 according to FIG. 7.Finally, FIG. 8 once again shows the cross section of the stopper 15 comprising two slots 25, into which the flat material of the half-strand 12 is introduced, similar to a tongue-and-groove connection.The embodiment of the invention is not limited to the preferred exemplary embodiment given above. Rather, a number of variants are conceivable which make use of the solution shown even in fundamentally different embodiments. All features and / or advantages arising from the claims, the description or the drawings, including structural details or spatial arrangements, can be essential to the invention both individually and in a wide variety of combinations.List of reference numbers:1 Leno edge device 10 lifting strand 11 foot 12 half strand 13 leg 14 half strand head 15 stopper 16 recess 17 holding geometry 18 holding edge 19 base edge 20 undercut 21 notch 22 holding nose 23 line of symmetry 24 lifting axis 25 slot 26 first thread 27 second thread 28 stop 29 holding projection

Claims

A leno edge device (1) for forming a leno edge comprising two opposing lever studs (10) which can be arranged on two mutually moved heald shafts of a weaving machine, and wherein the lever studs (10) have a foot (11) for connection to a respective heald support rail, wherein a half-heald (12) made of a metallic flat material is received between the lever studs (10), said half-heald having two limbs (13) which are connected to one another via a half-heald head (14), and wherein a respective stopper (15) is received on the limbs (13) of the half-heald (12) in order to abut against the foot (11) thereof during the lifting movement of the lever studs (10), wherein a recess (16) is formed in the limb (13), in which the stopper (15) is inserted, characterized in that, the recess (16) in the leg (13) has a contour which forms at least one holding geometry (17) for holding the stopper (15).Lathe edge device (1) according to claim 1, characterised in that the recess (16) has a U-shape, comprising two mutually opposite holding edges (18) and a base edge (19).Lathe edge device (1) according to claim 1 or 2, characterised in that the holding geometry (17) has at least one undercut (20).Lathe edge device (1) according to one of claims 1 to 3, characterised in that the at least one undercut (20) is introduced into the mutually opposite retaining edges (18) of the U-shaped cutout.Lathe edge device (1) according to one of the preceding claims, characterized in that the undercut (20) is formed as a notch (21) or as a retaining projection (29) in the retaining edge (18).Lathe edge device (1) according to one of the preceding claims, characterized in that the stopper (15) has at least one retaining lug (22) which is formed in a complementary manner to the notch (21) and latches into the notch (21) when the stopper (15) is inserted into the recess (16).Lathe edge device (1) according to one of the preceding claims, characterized in that the recess (16) has a line of symmetry (23), with respect to which the opposing retaining edges (18) extend mirror-symmetrically on both sides and along which the stopper (15) is joined into the recess (16).Lathe edge device (1) according to one of the preceding claims, characterized in that the two mutually opposite holding edges (18) run away from one another at an angle towards the base edge (19).Lathe edge device (1) according to one of claims 1 to 7, characterised in that the two mutually opposite holding edges (18) run towards one another at an angle to one another towards the base edge (19).Lathe edge device (1) according to one of the preceding claims, characterized in that the stopper (15) has lateral slots (25), into which the retaining edges (18) are inserted in a tongue-and-groove arrangement.Lathe edge device (1) according to one of the preceding claims, characterized in that the stopper (15) has an oversized portion relative to the recess (16) and / or is pressed into the recess (16) and / or comprises a polyamide.The leno-edge device (1) according to any one of the preceding claims, characterized in that the legs (13) of the half-strand (12) extend along a lifting axis (24), wherein the line of symmetry (23) of the recess (16) extends at an angle to the lifting axis (24) of 20° to 60° and / or of 30° to 50° and / or of 40°.

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