EP1770193A1 - Bar for a warp knitting machine and method of making same - Google Patents

Abstract

Needle bar (1) for a knitting machine comprises a needle holder (10) attached to a support (2) through an attachment surface having diagonal grooves (16). An independent claim is also included for producing a needle bar as above by forming the grooves in the attachment surface before attaching the needle holder to the support.

Description

The invention relates to a knitting machine bar with a support of a first material and a knitting tool receiving auxiliary element made of a second material, wherein the auxiliary element is fixed with a mounting surface on the carrier. Furthermore, the invention relates to a method for producing a knitting machine Barre, in which one attaches an auxiliary element by means of a mounting surface on a support.

Such knitting machine barre and a method for their preparation are, for example DE 43 02 858 C1 known. The auxiliary element is in this case provided with a plurality of grooves which extend substantially perpendicular to the longitudinal direction of the auxiliary element. After the auxiliary member is attached to the bar, it is divided into individual sections of a predetermined length.

DE 103 48 557 B3 shows a bar of a knitting machine, in which the auxiliary element also has grooves for receiving knitting tools. The grooves pass through the auxiliary element almost completely, so that only one strip foot remains, the thickness of which is relatively low compared to the transverse dimension of the knitting tools.

Ingots of knitting machines are often made of different materials, namely the carrier of a plastic, in particular in fiber-reinforced design, and a metal from which then the auxiliary element is formed. It makes use of the fact that you can form a carrier relatively massearm with plastic a required mechanical stability, while the auxiliary element made of metal can be made with the necessary precision so that the knitting tools can be arranged with the desired pitch.

For example, knitting needles are inserted into grooves or slots made with high accuracy and pressed against the bottom of the groove with a lid. The game between the flanks of the groove and the knitting needles may not exceed a predetermined level, usually 1/100 mm, but must be present. If the needle is thicker than the groove width, this leads to a bending of the webs remaining between the grooves. This complicates the insertion of other needles in adjacent grooves. If, however, the needle is thinner than the width of the groove by more than the predetermined amount, the needles will not hold properly during assembly.

Such precision is achieved with bars that are completely made of plastic, only with a relatively high cost. It therefore uses an auxiliary element for receiving the knitting tools, which indeed contributes to an increase in the moving mass, but can be made more precise.

If this auxiliary element is made of a metal, then it has a different thermal expansion than the carrier made of plastic. This leads in particular to problems if the bar has a greater length. In knitting machines bars with a length of over 6 m can occur.

The invention has for its object to maintain the pitch accuracy largely independent of the temperature.

This object is achieved in a knitting machine Barre of the type mentioned above in that the auxiliary element has diagonally extending grooves in the mounting surface.

As a result of the grooves, the auxiliary element is subdivided into individual segments. However, this subdivision is initially limited to the side facing the wearer. The direction "diagonal" means that the direction of the grooves does not coincide with the longitudinal direction of the bar, which is synonymous with the longitudinal direction of the auxiliary element, but also does not coincide with the transverse or width direction of the auxiliary element. In other words, in the longitudinal direction of the auxiliary member, a beginning of a groove has another one Distance to the end of the auxiliary element as the end of the groove. Up to the depth into which the grooves extend, the auxiliary element is then subdivided into individual sections in the longitudinal direction, without the stability of the auxiliary element during assembly, that is to say during attachment to the carrier, being appreciably impaired.

Preferably, each knitting tool position extends over at least one groove. This gives a design rule for the angle at which the grooves extend to the longitudinal edge of the auxiliary tool. Preferably, all grooves are parallel to each other.

Preferably, a distance between grooves maximally corresponds to a width of the auxiliary element. The distance is measured perpendicular to the course of the grooves. With this dimensioning, although the surfaces remaining between the grooves have a length that is greater than the width of the auxiliary element. But it is much smaller than the total length of the auxiliary element, so that make thermal expansions only in a relatively small extent noticeable.

It is even preferable that the distance between grooves is at most half of the width. The smaller the distance, the lower the effects of thermal expansion. However, the distance should not be too small, in order not to unduly impair the mechanical stability of the auxiliary element during assembly.

Preferably, the knitting tools are arranged in grooves whose depth extends to the grooves. In order to arise segments that are interconnected only by remaining in a bridge between grooves material bridges. Such an auxiliary element can then no longer transfer any appreciable forces to the carrier in the case of an expansion which is caused by heat change. Furthermore, the change in length is evenly distributed within a section between grooves on all knitting tools. The length-dependent changes are hardly measurable due to the short dimensions of the remaining segments between the grooves and do not interfere in the active process.

Preferably, the grooves have a depth which is at least 40% of the thickness of the auxiliary element. Thus, the grooves enforce the auxiliary element practically over half. Depths of up to 60% are also permissible.

Preferably, the auxiliary element and the carrier are glued together by an adhesive and the adhesive fills the grooves at least partially. On the one hand, the area over which the adhesive can rest against the auxiliary element is increased. On the other hand, the adhesive then in turn slightly increases the mechanical stability of the auxiliary element.

Preferably, the adhesive fills the grooves out to the grooves. In this way, when the grooves are formed, when the auxiliary member is already connected to the carrier, burrs are prevented from forming at the bottom of the grooves during processing.

The invention is achieved in a method of the type mentioned above by generating diagonally extending grooves before fastening in the mounting surface.

The diagonal grooves divide the auxiliary element in any case over part of its thickness into individual segments whose length is substantially less than the total length of the auxiliary element. Accordingly, thermal expansions in these sections may not exert as great a force on the carrier as with a solid auxiliary element.

In this case, it is preferred that the grooves are produced at an angle to the longitudinal direction of the auxiliary element, in which each knitting tool position crosses at least one groove. This specifies a design rule for the angle at which the groove extends to the longitudinal direction.

Preferably, the grooves are produced at a distance which corresponds at most to the width of the auxiliary element. Thus, the remaining between the grooves segments have a length parallel to the longitudinal extent of the auxiliary element, which is indeed greater than the width of the auxiliary element, but much smaller than the total length.

It is even more preferable that the grooves are formed at a distance which is at most half the width of the auxiliary member. This thermal stresses are kept even smaller.

Preferably, after the attachment of the auxiliary element to the carrier, grooves for receiving impact tools are produced. By introducing the grooves before attaching the auxiliary member to the carrier, the auxiliary member is not significantly weakened. So you can handle it easily and attach to the carrier. If you then produces the grooves in the later the knitting tools, such as the knitting needles are inserted, then this does not matter because the mechanical stability of the auxiliary member is ensured by the wearer. The grooves can be as wide or even wider than the grooves, without the storage of the knitting tools is adversely affected.

It is preferred that the grooves be made to a depth where they intersect the grooves. This results in segments of the auxiliary element, which are interconnected only by small material bridges, which are formed by webs which remain between individual grooves. These material bridges then interrupt the temperature-induced thermal expansions, so that basically only the thermal expansion of a single segment in the overall consideration is based. If the length of the individual segments is short enough, then such a change in length is hardly measurable.

Preferably, the grooves are produced with a depth corresponding to at least 40% of the thickness of the auxiliary element. This in turn can be exploited to keep the thickness of the strip foot, so the remaining between the bottom of the grooves and the mounting surface material area of the auxiliary element, relatively thick, for example, two to four times larger than the needle thickness.

Preferably, an adhesive which penetrates into the grooves is used to fasten the auxiliary element to the carrier. This increases the adhesive strength and the mechanical stability of the auxiliary element.

The grooves are preferably filled with the adhesive at least as far as the grooves. As a result, no burr can form on the edges of the apertures through machining.

Fig. 1

einen Schnitt durch eine Nadelbarre entlang der Linie I-I nach Fig. 2,

Fig. 2

eine Vorderansicht der Nadelbarre nach Fig. 1,

Fig. 3

einen Schnitt III-III nach Fig. 2,

Fig. 4

eine vergrößerte Einzelheit IV nach Fig. 3,

Fig. 5

eine perspektivische Darstellung eines Hilfselements ohne Barre und

Fig. 6

einen vergrößerten Ausschnitt VI aus Fig. 5.

The invention will be described below with reference to a preferred embodiment in conjunction with the drawings. Herein show:

Fig. 1

a section through a needle bar along the line II of Fig. 2,

Fig. 2

a front view of the needle bar of FIG. 1,

Fig. 3

a section III-III of FIG. 2,

Fig. 4

an enlarged detail IV of FIG. 3,

Fig. 5

a perspective view of an auxiliary element without barre and

Fig. 6

an enlarged detail VI of FIG. 5.

Fig. 1 shows a needle bar 1 with a carrier 2, which has a plurality of profiles 3, 4, 5, 6. These profiles are connected to each other and surround a cavity 7. The profiles 3-6 are formed from a plastic, in particular a carbon fiber reinforced plastic (CFRP). Each profile 3-6 is open and can be made by pressing.

The carrier 2 is fastened by means of a screw 7 to a drive lever 8 of a knitting machine.

The needle bar 1 carries a plurality of knitting needles 9, of which only one can be seen because the knitting needles 9 are arranged perpendicular to the plane one behind the other.

The knitting needles 9 are not attached directly to the carrier 2, but are arranged in an auxiliary element 10 having a plurality of grooves 11 which are separated by webs 12 from each other. Each groove 11 serves to receive a knitting needle 9. The auxiliary element rests with a mounting surface 19 on the carrier 2.

A clamping element 13, which is held by a screw 14 on the carrier 2, lies with the interposition of a layer 15 on the knitting needles 9 and holds them together with the auxiliary member 10 on the carrier 2.

As mentioned above, the carrier 2 is formed of a carbon fiber reinforced plastic. So he has a relatively low thermal expansion coefficient.

Length changes due to a change in temperature are therefore relatively small.

By contrast, the auxiliary element 10 is formed from a metal, for example aluminum or magnesium. Such a metal has a much higher coefficient of thermal expansion, so that temperature-induced changes in length are much greater. This can play a significant role, in particular, if the auxiliary element 10, which generally extends over the entire working width filled with knitting needles 9, has a length of several meters. In today's knitting machines lengths of over 6 m are quite possible.

The auxiliary element 10 is therefore provided with grooves 16 which extend diagonally across the auxiliary element 10 in the attachment surface 19. Diagonal means that the direction of the grooves 16 match neither the longitudinal direction of the auxiliary member 10 (in Fig. 2 from left to right) nor the width direction of the auxiliary member 10 (in Fig. 2 from bottom to top), but the grooves 16th with the longitudinal edge of the auxiliary element 10 include an acute angle α.

A distance a between adjacent grooves 16 (FIG. 5) should correspond at most to the width b of the auxiliary element 10 (from bottom to top in FIG. 2). However, a smaller distance a, in particular a distance a, which corresponds to a maximum of half the width b of the auxiliary element, is preferable.

The grooves 16 are also formed as grooves. But they are to distinguish them to the grooves 11 as grooves designated. The grooves 16 have a depth t which corresponds to at least 40% of the thickness d of the auxiliary element (in FIG. 4 from bottom to top). Even a greater depth of, for example, 60% of the thickness d of the auxiliary element 10 is preferable.

As can be seen from Figs. 4 and 6, the grooves 11 are inserted so deeply into the auxiliary member 10 that they intersect the grooves 16. As can be seen from Figs. 5 and 6, this results in that the auxiliary element is then formed of a plurality of segments 17, wherein the segments 17 are interconnected only by material bridges 18 which are not penetrated by the grooves 16 of the Remains of the webs 12 are formed. These material bridges 18 are relatively weak. No forces can be transmitted via the material bridges 18 which could lead to a deformation of the carrier 2.

In Figs. 5 and 6, the auxiliary member 10 (each in section) is shown in a "finished" form, i. it is provided with grooves 16 and grooves 11.

In fact, however, initially only the grooves 16 in the attachment surface 19 will be produced and then the auxiliary element 10 will be connected to the carrier 2 with the aid of an adhesive 20. As can be seen from FIG. 4, this adhesive 20 fills the grooves 16 with a region 20a, namely at least so far that in the subsequent production of the grooves 11, the grooves 11 extend into the region 20a, ie into the adhesive 20, penetrate. This avoids that in generating the grooves 11 at the groove bottom form burrs when a groove 11 a groove 16 intersects.

The angle α, which include the grooves 16 with the Längserstrekkung of the auxiliary element 10, should be selected so that each knitting needle 9 is located over at least one groove 16.

Characterized in that the auxiliary member 10 is provided only with the grooves 16 on its mounting surface 19 when it is connected to the carrier 2, it has sufficient stability. The bonding of the auxiliary element 10 with the carrier 2 can thus be done with conventional tools and measures.

After bonding the auxiliary element 10 with the carrier 2, the grooves 11 are then introduced. After that, the segments 17 within the auxiliary element 10, although only connected via the material bridges 18. However, this is not critical because all segments 17 are connected to each other via the carrier 2.

Claims (17)

Knitting machine bar (1) with a support (2) of a first material and a knitting tool (9) receiving auxiliary element (10) made of a second material, wherein the auxiliary element (10) with a mounting surface (19) attached to the carrier (2) is, characterized in that the auxiliary element (10) in the mounting surface (19) diagonally extending grooves (16). Bar according to claim 1, characterized in that each knitting tool position extends over at least one groove (16). Bar according to claim 1 or 2, characterized in that a distance (a) between grooves (16) corresponds to a maximum of one width (b) of the auxiliary element (10). Bar according to claim 3, characterized in that the distance (a) between grooves (16) corresponds to a maximum of half the width (b). Bar according to one of claims 1 to 4, characterized in that the knitting tools (9) are arranged in grooves (11) whose depth extends to the grooves (16). Bar according to one of claims 1 to 5, characterized in that the grooves (16) have a depth (t) which is at least 40% of the thickness (d) of the auxiliary element. Bar according to one of claims 1 to 6, characterized in that the auxiliary element (10) and the carrier (2) by an adhesive (20) are glued together and the adhesive (20) at least partially fills the grooves (16). Bar according to claim 7, characterized in that the adhesive (20) fills the grooves (16) up to the grooves (11). Method for producing a knitting machine bar (1), in which an auxiliary element (10) is fastened to a support (2) by means of a fastening surface (19), characterized in that , prior to fastening in the fastening surface (19), diagonal running Grooves (16) produced. Method according to Claim 9, characterized in that the grooves (16) are produced at an angle (α) to the longitudinal direction of the auxiliary element (10), in which each knitting tool position crosses at least one groove (16). Method according to claim 9 or 10, characterized in that the grooves (16) are produced at a distance (a) which corresponds at most to the width (b) of the auxiliary element (10). Method according to Claim 11, characterized in that the grooves (16) are produced at a distance (a) which corresponds at most to half the width (b) of the auxiliary element (10). Method according to one of claims 9 to 12, characterized in that , after the attachment of the auxiliary element (10) to the carrier (2), grooves (11) for receiving knitting tools (9) are produced. A method according to claim 13, characterized gekennzeich-. net, that one produces the grooves (11) to a depth in which they intersect the grooves (16). Method according to one of Claims 9 to 14, characterized in that the grooves (16) are produced with a depth (t) which corresponds to at least 40% of the thickness (d) of the auxiliary element (10). Method according to one of Claims 9 to 15, characterized in that an adhesive (20) which penetrates into the grooves (16) is used to fasten the auxiliary element (10) to the support (2). Method according to Claim 16, characterized in that the grooves (16) are filled with the adhesive (20) at least as far as the grooves (11).

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