EP0890668B1 - Stamped knitting tool for textile machines, particularly for knitting machines - Google Patents

Description

The invention relates to a punched knitting tool for textile machines, in particular knitting and warp knitting machines with a shaft in which at least one free space is formed is on its edge, at least in places, lined with at least one area of reduced shaft thickness and filled with a heterogeneous material is that is firmly connected to the shaft and in the area reduced shaft thickness protrudes.

Under "knitting tools" are tongue needles, point needles, Pushpins, needles without tongue, for example plush hooks for the production of plush goods and boards and to understand the like.

As for example in DE 44 42 943 C1 based on the there listed prior art explained in detail punched knitting tools are known in their shank at least one free space, for example in the form of an elongated hole is formed, the longitudinal axis of which is parallel or coaxial is aligned to the longitudinal axis of the shaft. This freedom is with a vibration damping heterogeneous material filled in, which is firmly connected to the needle shaft. In As a rule, this material is an elastic plastic material with high damping properties, but the Use of other materials is not excluded is.

Through the contained in the respective free space vibration-damping material becomes the vibration behavior of knitting tools beneficially influenced. It is possible the knitting tools to a highly elastic Dissolve structures in which the elongated hole is separated by two of the upper edge of the shaft to the lower edge of the shaft vertical guide parts and two connecting them narrow webs is limited, which are parallel to each other are arranged and their web height is at most approx. Is 1.1 mm. These knitting tools can last long Operating periods used at high working speeds without web breaks due to material fatigue or broken hooks occur to a significant degree. Because the spaces are filled and not open there is no fluff or dirt accumulate in the open spaces, depending on the Operating conditions, also occasionally as an advantage is looked at.

Since the vibration-damping filling the free space Material can only work if it is along the edge of the free space with the shaft material have been connected, especially in the case of very thin ones and in operation in the area of such a space lateral forces on bending stressed Knitting tools also have additional measures positive anchoring of the plastic filling in the Free space met. For this purpose, it is from EP-A1 0282 647 Applicant is known of the space-bordering web and / or To provide guide sections with a profile. The profiling can be areas of reduced wall thickness have, which are either arranged locally or afford like a bar over the entire outline - or one Part of it - the free space can extend. This Areas of reduced wall thickness protrude into the free space filling plastic material and contribute to its positive Anchoring to the shaft at.

To manufacture such knitting tools, especially of knitting machine needles with free spaces that reduced on the edges with profiled areas Shaft thickness are designed to facilitate, it is out the above-mentioned DE 44 42 943 C1 of the applicant, the Shank along the edge of the free space, at least in places, tapered towards the free space towards the inside form, the beveled areas in protrude the heterogeneous material that fills the free space. These sloping areas are usually in the Embossed shaft and arranged on both sides of the shaft.

In practice it has been shown that stamping this is wedge-shaped in cross section towards the free space tapered, bevelled edge areas at certain Needle types can be difficult. This stems from the fact that when embossing the edge area of the punched Freiraums shaft material, from the free space seen, is pushed outwards, with the result that uneven material accumulations in the the embossed Area surrounding shaft material may occur to undesirable changes in shape in the subsequently punched out Give the knitting tool a reason. When punching out Such a knitting tool is usually proceeded in such a way that initially from a flat steel strip the free spaces are punched out and embossed on the edge, followed by punching out the knitting tool done itself. Now experiences the knitting tool, originating from the previous embossing process, during this punching out a permanent change in shape, for example, by the fact that the shaft height in the area of the punched-out free space while balancing internal states of tension compared to the Punch size slightly increased, so under certain circumstances elaborate rework processes required.

The object of the invention is to remedy this and a To create knitting tools of the type mentioned at the beginning, that with perfect, positive anchoring of the respective free space in the shaft, heterogeneous material due to high dimensional accuracy and simple Manufacturing possibilities distinguished.

To solve this task, the knitting tool according to the invention the features of claim 1.

This knitting tool is at least on the edge of a free space, at least in places, the area reduced shaft thickness provided that a cross-sectional shape with a starting from an area minimal thickness on the side of the shaft, closer to one area of maximum thickness increasing in the free space Has thickness dimension.

The cross-sectional shape of the edge area with reduced Shaft thickness is usually at least approximate trapezoidal, but are also other cross-sectional profile shapes conceivable. The marginal area of reduced shaft thickness is advantageously stamped into the shaft, whereby it be profiled tooth-like at least in sections can.

Reduced by the formation of the edge area Stem thickness in the manner of a so-called "negative puncture" the occurrence of force components during the stamping process prevented that in the sense of an expansion of the Work with freedom. That which is plastically displaced during the embossing process Stock material moves towards the free space to what's harmless.

An improvement in the anchorage of the rule plastic heterogeneous material in the Freedom can be achieved, as already mentioned, the edge area of reduced shaft thickness, at least is profiled in sections, tooth-like. By this shape of holding teeth ensures that the plastic filling, even if it's in the knitting tool shrinks, still optimal also in the longitudinal direction of the shaft is held.

Further developments of the new knitting tool are Subject of subclaims.

Figur 1

ein Strickwerkzeug gemäß der Erfindung in Gestalt einer Zungennadel, in schematischer Darstellung und in einer Seitenansicht,

Figur 2

die Zungennadel nach Figur 1 in der Draufsicht,

Figur 3

die Zungennadel nach Figur 1 unter Veranschaulichung eines offenen, d.h. nicht mit einem heterogenen Material gefüllten Freiraums, im Ausschnitt und in einem anderen Maßstab

Figur 4

die Zungennadel nach Figur 3, geschnitten längs der Linie IV-IV der Figur 3 in einem anderen Maßstab und im Ausschnitt, unter gleichzeitiger Veranschaulichung der Prägewerkzeuge und

Figur 5

die Zungennadel nach Figur 3 in einer Querschnittsdarstellung entsprechend Figur 4, im Ausschnitt unter Veranschaulichung der sich beim Prägevorgang tatsächlich ergebenden Querschnittsprofilform, in einem anderen Maßstab.

In the drawing, embodiment of the object of the invention is shown. Show it:

Figure 1

a knitting tool according to the invention in the form of a latch needle, in a schematic representation and in a side view,

Figure 2

2 the latch needle according to FIG. 1,

Figure 3

the latch needle of Figure 1 illustrating an open, ie not filled with a heterogeneous material, in the cutout and on a different scale

Figure 4

the latch needle according to Figure 3, cut along the line IV-IV of Figure 3 on a different scale and in detail, while illustrating the embossing tools and

Figure 5

the tongue needle according to Figure 3 in a cross-sectional view corresponding to Figure 4, in a section illustrating the cross-sectional profile shape actually resulting during the embossing process, on a different scale.

The latch needle shown in FIGS. 1, 2 has a needle shaft 1, which is usually made of steel strip is punched out and two molded on top Feet 2 carries and on one side a needle head 3 with a needle hook 4. The one with the needle hook 4 interacting needle tongue is indicated at 5. In the needle shaft 1 are in the illustrated embodiment 4 spaced apart in the axial direction, continuous slots 6 punched, each of which forms a free space, which with a heterogeneous Material 8 is filled out. The heterogeneous material is with the shaft 1 along the edge of each slot 6 firmly connected. It’s usually made of a plastic, preferably a polyamide -12, polyurethane, polyethylene or polytetrafluoroethylene or the like, but are including in principle non-organic substances, e.g. understood metallic type.

Each slot 6 is through on its long sides two mutually parallel webs 9, 10 and on the end face by two from the upper edge 11 of the shaft to the lower edge 12 continuous guide parts 13 limited. Each foot is 2 each supported by one of the guide parts 13. The both on the upper needle shaft edge 11 and on the lower needle shaft edge 12 lying webs 9, 10 have a low height of preferably about 1.1 mm and less. Their length is advantageously more than 8 mm. The invention however is not on knitting tools with these dimensions limited.

In the illustrated embodiment, the outline is each slot 6 on the two webs 9, 10th adjacent long sides by essentially straight Lines 14, 15 delimited by two at the end faces approximately elliptically curved lines 16, 17 connected to one another are.

Which the respective elongated hole 6 on the long sides delimiting, essentially straight lines 14, 15 in the present case by three to that of the elongated hole 6 formed free space projecting holding teeth 19th interrupted, the width for a retaining tooth 19 at 20 is indicated and their protruding outline over radii 18 into the parts of the straight line connecting on both sides Lines 14, 15 merges.

Along the edge of each of one of the elongated holes 6 formed free space is the shaft 1 in the area of the two webs 9, 10 on both sides with one narrow, strip-shaped edge area of reduced shaft thickness provided, which is designated 20. How in particular the edge area shows from FIGS 20 reduced shaft thickness a cross-sectional shape based on an area 21 of minimal thickness on the side of the shaft 1 to a closer to that of the Elongated hole 6 formed area 22 maximum Thickness increases in its thickness dimension. In which The illustrated embodiment is the cross-sectional shape of the edge region 20 of reduced shaft thickness apparently approximated trapezoidal, with the respective Bridge 9 or 10, followed by a shorter baseline. A the area 21 of minimum thickness and the area 22 of maximum Thick connecting surface 23 closes in the illustrated Embodiment with the adjacent shaft side surface an angle 24 of approximately 10 °. The size this bevel angle 24 of the edge region 20 "Negative puncture" thus formed depends on the requirements and the geometric conditions of each Knitting tool. The angle is usually 24 in a range of approx. 5 ° to 60 °.

The thickness shown in FIG. 5 in the area 21 minimal. Thickness dimension is the one shown Embodiment at about 60% of the shaft thickness 26. In the Practice has depended on the circumstances of each Knitting tool, a minimum thickness range of about 20 to 80% and more of the shaft thickness 26 as appropriate proved.

The thickness (FIG. 5) in the area 22 of the largest thickness dimension is about 70% of the Shank thickness 26. Depending on the geometric and functional Conditions of the respective knitting tool the thickness dimension in this area is 22 maximum Thickness preferably between about 40% and 95% of the shaft thickness 26. In any case, the maximum thickness is 22 smaller than the shaft thickness 26, so that a safe anchoring of the plastic material filling 8 in the edge regions 20 remains guaranteed. The marginal areas 20 of reduced thickness protrude into the Plastic filling 8, in which they are embedded, wherein the projecting retaining teeth 19 an additional positive Anchoring.

The edge regions 20 described are reduced Shaft thickness is used in the manufacture of the latch needle stamped the shaft 1. This happens practically in the Way that from the band steel at each latch needle first the elongated holes 6 with the through the holding teeth 19th given contour are punched out. These elongated holes 6 are, as already explained, on their two opposite Long sides through the essentially straight Lines 14 and 15 (with the projecting retaining teeth 19) and at the end by one of the two straight lines 14, 15 interconnecting, essentially elliptical Outline 16 or 17 limited.

This is followed by on both sides of the shaft the web or strip-shaped edge regions 20 are reduced Shank thickness stamped into the shaft 1. this happens with the help of a cross section shown in FIG Embossing tool consisting of a die 29 and one of these assigned stamp 30 there. The die 29 and the embossing stamp 30 have mutually facing embossing surfaces 29a or 30a, which are recessed in a roof shape and consist of two flat surface sections, each enclose an obtuse angle 31, the Size results from the bevel angle 24 (Figure 5).

The axial length of the die 30 (and die 29) is shorter than the length of the associated elongated hole 6. It extends in the longitudinal direction only between the two semicircular arches entered with dashed lines in FIG. 3 28. This means that those in the shaft 1 embossed areas 20 of reduced shaft thickness only on the opposite long sides of the Elongated hole 6 between the two designated 32 Boundary lines that lie approximately at the point that of the respective end stop tooth 19 in the elliptical arch 16 or 17 merges.

When the areas 20 of reduced shaft thickness are impressed stamping surfaces 29a, 30a of die 29 and of the die 30 starting with its outer edge in the shaft material. Since the embossing surfaces 29a and 30a are inclined backwards, they have Imprinting forces to the free space formed by the elongated hole 6 inclined, facing components that the plastically deformed material strives to To press free space, with which an expansion of the elongated hole 6 and an associated uneven deformation the webs 9, 10 can be avoided. This to the The free movement of material is shown in FIG. 5 a gusset formation in the region of the end face at 33 seen. The end face 33 consists of two from the edge inwards to convexly curved partial surfaces, which are approximately meet in the longitudinal plane of symmetry of the shaft 1.

After completing the embossing, the tongue needle blank punched out of the strip steel and its other Processing supplied, in the course of which Plastic filling 8 is introduced into the elongated holes 6. Since the areas 20 of reduced wall thickness do not overlap the ellipse arches 28 on the end faces of the elongated holes 6 extend, the plastic is not on these end faces positively connected to the shaft 1. This has been in particular on the oblong hole end faces facing a foot 2 proven to be useful.

The one measured perpendicular to the longitudinal axis 34 of the shaft Width of one of the areas 20 of reduced shaft thickness is typically about 0.1 to 0.5 mm, preferably about 0.2 mm.

In the illustrated embodiment, the Clearances in the shaft 1 in the form of elongated holes 6 trained. The invention is not limited to but on open spaces with any, each Appropriate outline shape of the edge applicable. "Open spaces" also includes open-cut sections etc. understood in shaft 1.

Claims (11)

1. Stamped knitting tool for textile machines, in particular knitting and warp knitting machines, with a blade (1) of given blade thickness (26), in which at least one free space is formed, which is bordered, at least in sections, at its edge by at least one region (20) of reduced blade thickness and which is filled with a heterogeneous material (8), which is firmly joined to the blade (1) and into which the edge region (20) of reduced blade thickness projects, characterised in that the edge region (20) of reduced blade thickness has a cross-sectional form with a thickness dimension, which increases extending from a region (21) of minimal thickness on the side of the blade (1) to a region (22) of maximum thickness located closer to the free space (6), and which is smaller than the blade thickness (26).
2. Stamped knitting tool according to Claim 1, characterised in that the cross-sectional form of the edge region (20) of reduced blade thickness is at least approximately trapezoidal.
3. Stamped knitting tool according to Claim 2, characterised in that a surface (23) of the edge region (20) connecting the region (21) of minimal thickness and the region (22) of maximum thickness encloses an angle (24) of approximately 5° - 60°, preferably approximately 10°, with the respectively adjacent blade side surface.
4. Stamped knitting tool according to one of the preceding claims, characterised in that the edge region (20) of reduced blade thickness is profiled in a tooth-like manner at least in sections (at 19).
5. Stamped knitting tool according to one of the preceding claims, characterised in that the edge region (20) of reduced blade thickness is impressed into the blade (1).
6. Stamped knitting tool according to one of the preceding claims, characterised in that edge regions (20) of reduced blade thickness are arranged on both sides of the blade.
7. Stamped knitting tool according to one of the preceding claims, characterised in that the thickness in the region (22) of maximum thickness amounts to between approximately 40% and 95% of the blade thickness (26).
8. Stamped knitting tool according to one of the preceding Claims 1 to 6, characterised in that the thickness in the region (21) of minimal thickness amounts to between approximately 20% and 80% of the blade thickness (26).
9. Stamped knitting tool according to one of the preceding claims, characterised in that, in the case of a free space configured in the form of an elongated hole, edge regions (20) of reduced blade thickness are provided on the opposing longitudinal sides of the edge of the hole.
10. Stamped knitting tool according to Claim 9, characterised in that at least one of the faces (at 16, 17) of the edge of the hole that connect the two longitudinal sides to one another is constructed without a region (20) of reduced blade thickness.
11. Stamped knitting tool according to Claim 10, characterised in that, in the case of a blade (1) bearing at least one butt (2), the face (17) of the respective elongated hole adjacent to the butt is constructed without a region (20) of reduced thickness.

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