EP3268526B1 - Needle cylinder and circular knitting machine - Google Patents

Description

The present invention relates to a needle cylinder of a circular knitting machine, on the cylinder jacket of which there is a plurality of needle channels extending in axial cylinder alignment with knitting needles movable therein and in the upper cylinder end of which is provided for loop formation between each pair of adjacent needle channels, in each case a radially aligned groove each of which at least one insert is provided which, with its insert surface protruding from the respective groove, forms a loop formation surface. The invention also relates to a circular knitting machine with such a needle cylinder.

Single-cylinder circular knitting machines have a single-cylinder needle bed on the outer surface of the needle cylinder with a large number of needle channels running vertically next to one another in which knitting needles, such as latch needles, are moved up and down in a guided manner. To form loops, the knitting needles interact with a ring of radially moving scrapers, so-called sinkers or sinkers, the movement of which is coordinated with the up and down movement of the knitting needles.

However, there are also circular knitting machines without such scrapers or with fixed scrapers. In such circular knitting machines webs made of solid material are provided between adjacent knitting needles, the surfaces of which form loop-forming surfaces. On the surfaces of these webs, however, the yarn continuously rubs at the same points during the loop-forming process, as a result of which a high material wear occurs on the surfaces of the webs.

In the prior art, therefore, initially hardened cylinder material was used to form the webs. However, this has the disadvantage that the curing decreases the flexibility of the cylinder material and the surface treatment does not ensure an optimal sliding surface for the yarn. In addition, it is necessary to design the webs with the smallest possible thickness in order to have sufficient space for the movement of the knitting needles guided between the webs and the passage of the yarn during the loop formation. However, this requirement is not compatible with the fragility of the hardened bar material.

In further approaches in the prior art, the webs were formed from a different material than the cylinder, that is to say as separate elements which were glued into corresponding cut-out areas at the upper end of the cylinder. Although such inserts can be made of more abrasion-resistant material than the cylinder, they are still subject to the wear described above, which is why they or even the entire cylinder must be replaced after a considerable period of use. Such an exchange is associated with longer machine downtimes and corresponding production losses.

In order to remedy this disadvantage, the document WO 2014/060325 A1 proposed a needle cylinder of the type mentioned with interchangeable inserts. The inserts are placed in radially aligned grooves which are each provided between a pair of adjacent knitting needle channels in such a way that the insert surface of the respective insert protruding from the respective groove forms a loop formation surface.

The one in the pamphlet WO 2014/060325 A1 The inserts described have a dovetail-shaped extension which is inserted into an undercut of an annular channel provided at the upper end of the cylinder and intersected by the radially aligned grooves. The inserts are held in the grooves with the extension inserted into the undercut by a retaining ring running around the cylinder side with a surface that presses against the insert, the retaining ring being fixed by a screw connection on the inside of the cylinder.

To replace the inserts, the screw connection must therefore be loosened, the retaining ring removed, the worn insert to be replaced pushed out of the undercut, removed from the groove and a new insert provided in reverse order. This procedure is relatively complex and therefore associated with longer machine downtimes.

In the pamphlet EP 2 108 725 A1 describes a sinker set for a knitting system for the production of plush goods. The sinker set has a sinker and a Plush board, each having flat sides and, in use, rest against each other with two flat sides facing each other. The plush sinker is arranged in a sinker channel of a sinker ring, while the sinker sits in a channel formed on a knitting cylinder. Starting from the end face of the knitting cylinder, this channel extends over one of its wall surfaces, whereby the sinker is held in place. The sinker is held positively on the knitting cylinder, for which purpose the sinker is C-shaped. To hold the sinker on the knitting cylinder, projections are provided on the legs of the C, which are aligned parallel to one another. The sinker has a wide support section that bridges the distance between adjacent plush sinkers.

It is therefore the object of the present invention to provide a needle cylinder of the above-mentioned type and a circular knitting machine with such a needle cylinder with exchangeable inserts that form loop-forming surfaces, the exchange of which is associated with a reasonable expenditure of time.

On the one hand, the object is achieved by a needle cylinder of a circular knitting machine, on the cylinder jacket of which there is a plurality of knitting needle channels extending in axial cylinder alignment with knitting needles movable therein and in the upper cylinder end of which is provided for loop formation between each pair of adjacent knitting needle channels is, in each of which at least one insert is provided which, with its insert surface protruding from the respective groove, forms a loop formation surface, the insert being designed in the form of a spring clip, the spring clip having an upper cylinder end on the side of the cylinder jacket or a side edge an outer ring channel provided in the upper end of the cylinder and a bracket foot that extends over the upper cylinder end on the inside of the cylinder or a side edge of an inner ring channel provided in the upper end of the cylinder nde U-clamp with at least one clamp section resiliently engaging behind a counterhold, and wherein the U-clamp is S-shaped.

The insert, designed as a spring clip according to the invention, can simply be inserted into one of the radially aligned grooves provided on the upper cylinder end and clamped onto the upper cylinder end. By being inserted into the groove, the insert is fixed in position in the circumferential direction of the cylinder. By clamping the insert, it is also fixed in position in the radial direction.

The foot of the spring clip is either guided around the upper cylinder end on the cylinder jacket side or it clamps on a side edge of an outer ring channel that is not made on the cylinder jacket side but in the surface of the upper cylinder end. In the present invention, the term "outer ring channel" means that the outer ring channel is closer to the cylinder outer or cylinder jacket side than to the cylinder inner side and does not mean that an inner ring channel must also be present.

The U-clamp is either guided around the upper end of the cylinder on the inside of the cylinder and with a clamp section engages behind a counter support formed on the inside of the cylinder, or the U-clamp clamps on a side edge of an inner ring channel introduced into the surface of the upper end of the cylinder. In the present invention, the term "inner ring channel" means that the inner ring channel is closer to the inside of the cylinder than to the outside of the cylinder or the cylinder jacket side lies and does not mean that an outer ring channel must also be present. In certain embodiments of the present invention, neither an outer nor an inner ring channel is present. In still other embodiments of the present invention, there is both an outer and an inner ring channel.

After the spring clip has been inserted into the groove, the insert surface of the spring clip protrudes from the groove and forms a loop forming surface.

In order to replace the insert in the needle cylinder according to the invention, all that is required is to disconnect a worn spring clip to be replaced from the upper end of the cylinder. The insert proposed according to the invention therefore holds itself on the needle cylinder through its own spring tension and can therefore be easily assembled and disassembled.

Additional holding and / or fixing elements, such as that in the circular knitting machine of the publication WO 2014/060325 A1 Required retaining ring, the associated screw connection and a seat on the inside of the cylinder, on which the retaining ring can be screwed to the cylinder, or an adhesive fixation of the insert are not necessary with the present invention. Machine downtimes for replacing worn inserts can therefore be minimized in terms of time with the needle cylinder according to the invention.

In addition, the insert according to the invention has the advantage that it can be made from a material with better abrasion properties than the other cylinder material and, through its surface, can form a sufficiently large loop formation area with good sliding characteristics for the yarn guided over it. In addition, the simplicity of construction and the fastening of its inserts make the needle cylinder according to the invention less expensive to manufacture and maintain.

In an advantageous embodiment of the present invention, the counterhold is formed by a nose-shaped projection on the inside end of the cylinder bordering the upper cylinder end or the inner ring channel, with a bulge on the counterhold on the inside of the cylinder or within the inner ring channel to accommodate the spring engaging behind the counterhold Terminal section of the U-clamp connects. The nose-shaped projection forms a suitable one Guide for positioning the insert at the edge area between the surface of the upper end of the cylinder and the inside of the cylinder or the inner ring channel. The bulge adjacent to the counterhold secures the clamping of the U-clamp on the inside of the cylinder or within the inner ring channel.

According to a preferred embodiment of the needle cylinder according to the invention, the insert between the bracket foot and the bracket clamp has a support area located in the groove, with cutouts being provided in the insert between the support area and the bracket foot and between the support area and the bracket clamp. The punching technique preferably used for the manufacture of the insert means that certain tolerances in the dimensions of the insert, in particular in its inner corner areas, around which the upper end of the cylinder are guided, are unavoidable. The cutouts therefore ensure that the insert rests snugly with its bearing surface on the groove base even with existing manufacturing tolerances, as a result of which the insert surfaces protruding from the grooves are on one level.

If the ironing foot is provided on the cylinder jacket side in the needle cylinder according to the invention, it is particularly advantageous if a nose-shaped protruding guide for the ironing foot is provided for easier positioning at the cylinder jacket end bordering the upper cylinder end. The remaining area of the cylinder jacket side is set back in relation to the nose-shaped projection in relation to the dial of the circular knitting machine.

It has also proven to be advantageous if, in the present invention, the insert on the cylinder jacket side, between the insert surface forming the loop forming surface and the stirrup foot, has a recess area set back compared to the end of the loop forming surface facing a dial of the circular knitting machine. The preferably concave recess area reduces the risk of contact between the tongue of the knitting needle and the insert when the tongue needle performs an opening movement after the stitch formation point. In addition, this form of insert reduces the area on which dirt can collect.

In particular, the cleaning of the indentation area and / or the ironing foot can easily be carried out by means of air nozzles directed thereon.

In a structural design of the needle cylinder according to the invention that has proven to be particularly advantageous, it is provided that the hoop foot is designed in the form of a closed round bracket and the hoop clamp is S-shaped. This results in a particularly good hold of the insert on the upper end of the cylinder.

The object is also achieved by a circular knitting machine with a needle cylinder according to the invention.

Figur 1

schematisch einen Ausschnitt einer erfindungsgemäßen Rundstrickmaschine mit einem Einsatz, der ein oberes Zylinderende an der Zylindermantelseite und an der Zylinderinnenseite übergreift, und mit zurückgezogener Stricknadel in einer geschnittenen Querschnittsansicht zeigt;

Figur 2

schematisch den Ausschnitt der Rundstrickmaschine aus Figur 1 mit ausgefahrener Stricknadel in einer geschnittenen Querschnittsansicht zeigt;

Figur 3

schematisch einen in der Rundstrickmaschine der Figuren 1 und 2 am oberen Zylinderende als Abstreifer verwendeten Einsatz in einer perspektivischen Darstellung zeigt;

Figur 4

schematisch einen oberen Abschnitt der Rundstrickmaschine der Figuren 1 und 2 mit Veranschaulichung des unter Federspannung fixierten Einsatzes in einer geschnittenen Querschnittsansicht zeigt;

Figur 5

nochmals schematisch den in Figur 4 gezeigten Abschnitt der Rundstrickmaschine mit unterschiedlicher Schraffierung von Teilkomponenten der Rundstrickmaschine in einer geschnittenen Querschnittsansicht zeigt;

Figur 6

schematisch einen oberen Abschnitt der Rundstrickmaschine der Figuren 1 und 2 zeigt, wobei sich eine Stricknadel mit ihrer Zunge im Bereich des Einsatzes befindet und auf diesen Bereich des Einsatzes Luftdüsen ausgerichtet sind; und

Figur 7

schematisch eine weitere Ausführungsform eines oberen Abschnittes einer erfindungsgemäßen Rundstrickmaschine mit einem Einsatz, der ein oberes Zylinderende an eine Zylinderinnenseite und eine Seitenkante eines in dem oberen Zylinderende vorgesehenen äußeren Ringkanals übergreift, in einer geschnittenen Querschnittsansicht zeigt.

Preferred embodiments of the present invention, their structure, function and advantages are explained in more detail below with reference to figures, wherein

Figure 1

shows schematically a section of a circular knitting machine according to the invention with an insert which overlaps an upper cylinder end on the cylinder jacket side and on the inside of the cylinder, and shows a cut-away cross-sectional view with the knitting needle withdrawn;

Figure 2

schematically the section of the circular knitting machine Figure 1 shows with extended knitting needle in a cross-sectional view;

Figure 3

schematically one in the circular knitting machine of Figures 1 and 2 shows insert used as a wiper at the upper end of the cylinder in a perspective view;

Figure 4

schematically an upper section of the circular knitting machine of FIG Figures 1 and 2 with an illustration of the insert fixed under spring tension in a cross-sectional view;

Figure 5

again schematically the in Figure 4 shows the section of the circular knitting machine shown with different hatching of subcomponents of the circular knitting machine in a sectional cross-sectional view;

Figure 6

schematically an upper section of the circular knitting machine of FIG Figures 1 and 2 shows, wherein a knitting needle is with its tongue in the area of the insert and air nozzles are aimed at this area of the insert; and

Figure 7

shows schematically a further embodiment of an upper section of a circular knitting machine according to the invention with an insert which overlaps an upper cylinder end on an inner side of the cylinder and a side edge of an outer ring channel provided in the upper cylinder end, in a sectional cross-sectional view.

In the figures, the same reference symbols denote identical or similar elements, which is why a description of an element which is given below with reference to a figure also applies to the same reference symbols in the other figures.

The Figures 1 and 2 schematically show a detail of a circular knitting machine 10 according to the invention in a cut cross-sectional view. The circular knitting machine 10 is a single-cylinder circular knitting machine. The diameter of the circular knitting machine 10 is arbitrary.

The circular knitting machine 1 has an upright needle cylinder 1 and a dial 2 oriented transversely to the needle cylinder 1. The needle cylinder 1 has a cylinder jacket 3 with a plurality of needle channels 4 spaced from one another in the circumferential direction of the needle cylinder 1 and extending in the axial cylinder orientation A with knitting needles 5 movable therein, which are here in the form of latch needles, but also others in other embodiments of the present invention stitch-forming needles can be on. The number of needle channels 4 and the knitting needles 5 located therein is dependent on the fineness of the circular knitting machine 10, 10 ′.

The knitting needles 5 each have a needle butt 51, as a result of which they can be moved up and down with a lock mechanically coupled to the needle butt 51 in the present figures. In the embodiment shown, the knitting needles 5 are held in the needle channels 4 by annular springs 52.

In the representation of Figure 1 the knitting needle 5 is in a retracted position, while the knitting needle 5 is shown in FIG Figure 2 is in an extended position.

The needle cylinder 6 has an upper cylinder end 6 which is designed in the form of a flattened cylinder upper edge which runs around the cylinder circumference. According to the invention, the upper cylinder end 6 is understood to mean that cylinder end from which the heads 53 of the knitting needles 5 protrude during the loop formation process. Radially extending grooves 7 are made in the upper end of the cylinder 6 and each extend between a pair of needle channels 4. The grooves 7 have a substantially flat, horizontally extending groove bottom and are straight cuts running through the entire cylinder thickness.

An insert 8 can be introduced into each of the grooves 7. The insert 8, which is in the in the Figures 1 and 2 circular knitting machine 10 shown is used in FIG Figure 3 shown enlarged in a perspective illustration.

The insert 8 is designed in the form of a spring clip with a flat cross section. The thickness of the spring clip is somewhat less than the width of the groove 7, so that the insert 8 can be inserted into the groove 7 simply but still tightly. The thickness of the insert 8 can be greater in its lower area to be inserted into the groove 7 than in its upper area protruding from the groove 7 in order, on the one hand, to ensure stable guidance of the insert 8 in the groove 7 and, on the other hand, enough space for the To provide yarn in the knitting process. However, the thickness of the insert 8 can also be constant in all of its areas. The radial extension of the insert 8 is greater than the radial extension of the groove 7.

The spring clip has a clip foot 82 that overlaps the upper cylinder end 6 on the side of the cylinder jacket 3. In the exemplary embodiment shown, the bracket foot 82 is designed in the form of a closed round bracket. As can be seen more clearly from the enlarged illustration of an upper section of the circular knitting machine 10 in FIG Figure 4 As can be seen, the ironing foot 82 at the end of the cylinder jacket 3 adjoining the upper cylinder end 6 engages around a nose-shaped projecting guide 31a for the ironing foot 82.

The insert 8 furthermore has a U-clamp 83 which overlaps the upper cylinder end 6 on the inside 9 of the cylinder. According to the invention, the U-clamp 83 is S-shaped. The bracket clamp 83 initially has a convex clamp section 831 protruding from the upper cylinder end 6 and then merges into a concave clamp section 832 protruding towards the inside of the cylinder 9. The clamp portion 832 forms a spring element which, as in FIG Figure 4 good to see, a provided on the inside 9 of the cylinder counterhold 91 engages resiliently behind. A bulge 92 adjoins the counterhold 91 on the inside of the cylinder 9, in which the clamp section 832 of the U-clamp 83, which resiliently engages behind the counterhold 91, is received. In this embodiment of the present invention, the bracket clamp 83 is provided on an end of the insert 8 that is directed towards the inside 9 of the cylinder.

In other, not shown embodiments of the present invention, however, the U-clamp can also be provided at a distance from the end of the insert 8 directed towards the inside 9 of the cylinder. In this case, an inner annular channel intersecting the grooves 7 is provided in the upper cylinder end 6 with a, for example, nose-shaped counter-hold formed therein. The U-clamp is then inserted into the inner ring channel in such a way that it engages behind a side edge of the inner ring channel that is further away from the cylinder inner side 9 and, in the process, engages behind the counter-hold formed on this side edge.

The insert 8 protrudes from the groove 7 and, with its insert surface 81, forms a mesh-forming surface or wiper surface. In the embodiment shown, the insert surface 81 has a first insert surface area 811, which is inclined downward in the direction of the cylinder inner side 9, and a second, horizontally extending insert surface area 812.

The insert 8 may have a wear reducing coating or treatment provided in at least the insert surface area 812.

How it looks, for example Figure 3 relating to Figure 5 , in which the needle cylinder 1 is shown hatched for the sake of clarity, the insert 8 has a support area 84 with which it rests flat on a groove bottom of the groove 7. Here are between the support area 84 and the Bracket foot 82 and between the support area 84 and the bracket clamp 83 cutouts 85, 86 are provided in the insert 8.

The insert 8 has, on the side of the cylinder jacket 3, between the insert surface 81 forming the loop forming surface and the stirrup foot 82, a recess area 88 set back in relation to the end 87 of the loop forming surface facing the dial 2 of the circular knitting machine 10.

Figure 6 FIG. 12 schematically shows an upper portion of the circular knitting machine of FIG Figures 1 and 2 , wherein a knitting needle 5 with its tongue 54 is in the area of the insert 8 and air nozzles are aligned with this area of the insert.

Figure 7 shows schematically an upper section of a further possible embodiment of a circular knitting machine 10 ′ according to the invention in a cut cross-sectional view.

The circular knitting machine 10 'has a needle cylinder 1' with a cylinder opposite the upper end 6 from the embodiment of FIG Figures 1 to 6 modified upper cylinder end 6 '. In the upper end of the cylinder 6 ', an outer ring channel 30 running in the circumferential direction of the needle cylinder 1' is formed. The outer ring channel 30 intersects the grooves 7.

Furthermore, the circular knitting machine 10 'has an opposite to the insert 8 of the embodiment of FIG Figures 1 to 6 modified insert 8 'on. The insert 8 ', like the insert 8, has a U-clamp 83 with the features described above that overlaps the upper cylinder end 6' on the inside of the cylinder 9, but does not engage behind the upper cylinder end 6 'on the side of the cylinder jacket 3 Insert 8 'has a bracket foot 82' which engages behind a side edge 31 of the outer annular channel 30 that is further away from the cylinder jacket 3.

The inserts 8, 8 'interact with corresponding reciprocating elements 21, which are received in horizontal guide channels in the dial 2 of the respective circular knitting machine 10, 10'. The dial 2 is in each case arranged coaxially to the needle cylinder 1, 1 ′ and attached to it via a foot 55.

Each movable element 21 has a finger 22 pointing radially in the direction of the inside of the cylinder 9 and passes over the insert surface 81 when it moves horizontally Stripping or sinking is taken over. The movable elements 21 hold the loop close to the loop forming surface which is formed by the insert surface 81 of the inserts 8, 8 'when the knitting needle 5 is raised, so that the loop is not lifted up by the upward movement of the knitting needle 5 but in the direction of the Needle cylinder center is pressed, whereby the contact of the loop with the knitting needle 5 is maintained.

While a movable element 21 has moved radially inward above the needle cylinder 1, 1 ', a knitting needle 5 moves upwards with the yarn. The finger 22 of the movable member 21 then holds the yarn, thereby preventing it from being lifted up by the upward movement of the knitting needle 5. The upward movement of the knitting needle 5 is continued until the loop is released from the opened tongue 54 of the knitting needle 5.

This results in increased mechanical stress on the insert surface 81 compared to the other areas of the needle cylinder 1, 1 '. If the inserts 8, 8 'are therefore worn out over time, they can be removed by simply clamping them off from the upper cylinder end 6, 6' and replaced with new inserts 8, 8 'by simply inserting the new inserts 8, 8' into the grooves 7 and can be replaced by simply clamping the new inserts 8, 8 'onto the upper cylinder end 6, 6'.

The embodiments described above can alternately be combined with one another with regard to individual features. The insert 8, 8 'can be formed from one or more individual parts connected to one another and / or from one or more materials or material combination (s).

Claims (8)

1. Needle cylinder (1, 1') of a circular knitting machine (10, 10'), on the cylinder casing (3) of which a plurality of needle channels (4) extending in the axial cylinder alignment (A) is provided having knitting needles (5) that are movable therein, and, in the upper cylinder end (6, 6') of which that is provided for loop formation, a radially aligned groove (7) is provided between each pair of adjacent needle channels (4), in each of which grooves at least one insert (8, 8') is provided, the insert surface (81) of which protruding from the particular groove (7) forms a loop formation surface, and
   the insert (8) is designed as a spring clip, the spring clip having a clip base (82, 82') that overlaps the upper cylinder end (6, 6') on the side of the cylinder casing (3) or a side edge (31) of an outer ring channel (30) provided in the upper cylinder end (6'), and having a clip clamp (83) that overlaps the upper cylinder end (6) on the cylinder interior (9) or a side edge of an inner ring channel provided in the upper cylinder end (6'), the clip clamp having at least one clamp portion (832) resiliently engaging behind a counter support (91),
   characterized in that
   the clip clamp (83) is S-shaped.
2. Needle cylinder according to claim 1, characterized in that the counter support (91) is formed by a lug-like projection at the end of the cylinder interior (9) or of the inner ring channel that borders the upper cylinder end (6, 6'), and a bulge (92) for receiving the clamp portion (832) of the clip clamp (83) which resiliently engages behind the counter support (91) adjoins the counter support (91) on the cylinder interior (9) or in the inner ring channel.
3. Needle cylinder according to at least one of the preceding claims, characterized in that the insert (8, 8') has a contact region (84) between the clip base (82, 82') and the clip clamp (83) in the groove (7), cut-outs (85, 86) being provided in the insert (8, 8') between the contact region (84) and the clip base (82, 82') and between the contact region (84) and the clip clamp (83).
4. Needle cylinder according to at least one of the preceding claims, characterized in that a guide (31a) protruding in a lug-like manner is provided for the clip base (82) at the end of the cylinder casing (3) bordering the upper cylinder end (6).
5. Needle cylinder according to at least one of the preceding claims, characterized in that the insert (8, 8') has, on the side of the cylinder casing (3), between the insert surface (81) forming the loop formation surface and the clip base (82, 82'), a recess region (88) that is recessed with respect to the end (87) of the loop formation surface that is nearer a dial (2) of the circular knitting machine (10, 10').
6. Needle cylinder according to claim 5, characterized in that air nozzles are provided on the needle cylinder (1, 1'), which air nozzles are aligned with the recess region (88) and/or the clip base (82).
7. Needle cylinder according to at least one of the preceding claims, characterized in that the clip base (82, 82') is designed as a closed round retaining clip.
8. Circular knitting machine (10, 10') comprising a needle cylinder (1, 1') according to at least one of the preceding claims.

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