EP1069226B1 - Sewing machine needle with improved loop formation - Google Patents

Description

The invention relates to a needle, in particular for mechanical penetration of a thread into sewing material.

When sewing sewing material is a thread, the so-called Upper thread, by means of a needle, which is close to her Tip is provided with an eye, running through the Sewed material. When retracting the needle This results in a sling made by a loop taker captured and through which another thread, the so-called Lower thread, being pulled. It creates a from upper and Lower thread existing seam. To the bobbin thread through the To be able to draw a sling, the sling becomes with the Greater grasps and enlarges them by one Winding around the bobbin case, in which the bobbin thread located. To this end, the loop snatcher first becomes upper thread followed, then pulled back through the eye becomes. The upper thread therefore passes through the eye of the needle many times and is thus heavily used.

In addition, there are sewing operations in which the Upper thread is stung in or through the sewing material, without that a gripper the thread and the forming loop when retracting the needle holds. Should be reliable here form a loop, the thread must be through friction be held between him and the sewing material.

From US-PS 3,523,510 is a tufting needle for Known carpet making, which serves a staple fiber yarn to sting through a ground fabric and with the Staple fiber yarn to form loops. The tufting needle has an approximately cylindrical shaft, the on an end is pointed. Near the top is formed obliquely to the needle central axis a funnel-shaped eye. In the tufting needle an air duct is provided with which the eye can be acted upon by compressed air. In connection to the eye are at both opposite each other Sides of the tufting needle formed shallow grooves, whose depth is less than the smallest diameter of the Eyelet. Following the eye, the shaft is to the clamping side cylindrical and tapered towards the tip. The inclination of the eye to the longitudinal axis is about 30 °.

The looping is in this needle by the Effect of compressed air introduced into the eye. Other means for holding the thread loop are not seen.

Another tufting needle is known from EP 0187925. This is based on a tubular body, which is cut off obliquely to form a tip. At the opposite side of the slope is the tubular Base body also open, leaving a through the open interior running thread on the oblique arranged mouth surface of the tubular body can escape. The eyelet thus formed has an oval Cross-section, due to a the tubular body The deformation along the eye changes. On the open side of the tubular body opposite side is the tubular body flattened, so that formed a recess or groove is.

Another tufting needle is known from DE 2834738 C2 known. This needle has a needle body with a flat Cross-section, resulting in one embodiment extends almost unchanged to an eye, the cross directed to the longitudinal axis of the needle and elongated oval is. To the eye leads a gutter that considerably flatter than the thread. The length of the eye is at this Embodiment about as large as the mouth of the eye at the two corresponding opposite one another Needle pages.

In a modified, from said DE 2834738 C2 previously known, embodiment (Figure 5 of the patent) is a tufting needle with approximately spoon-shaped Head known. Along the shaft extends a thread trough, their depth is less than the thread thickness and essential less than the eye width. The eye is oval formed and extends across the tufting needle. At the opposite side of the yarn channel is in Area of the eye and a subsequent shaft area a deflection provided.

Similar tufting needles are known from DE 3002345 C2, U.S. Patent 4,502,403 and U.S. Patent 4,233,917.

From DE-OS 2412062 is also a sewing needle known to cooperate with a thread-gripper is set up. The sewing needle serves to the upper thread to pierce through the fabric, with the forming Loop then held by a thread grab and enlarged becomes. The sewing needle has a shaft with a thread groove whose depth is slightly greater than that smallest eye diameter, so that the thread. completely in the thread trough is running. The eye extends to one arched path across the needle and widens thereby funnel-shaped. The eye cross-section is set oval. Immediately following the eye is at the of facing away from the tip and the thread trough opposite Side a trough provided for the hook or gripper, who works with the needle.

On this basis, it is an object of the invention, a To create a needle with improved loop formation.

This task is solved with a needle, which the Features of claims 1 or 2.

The needle of the invention has a long, the thread good leading eye and one adjacent to the Öhrausgang Bump for clamping the thread in the sewing material. The eye is through a preferably straight passage formed at an acute angle to the needle longitudinal direction is inclined. This gives a low friction of the through the eye thread at the eye and a good Guiding the thread.

In conjunction with the arranged on the needle back Bump becomes a retraction of the thread through the eye of the needle and thus contraction of the needle during the insertion process avoided generated thread loop. With the The needle according to the invention can therefore produce a loop which, when retracting the needle in its ideal way full training is maintained. The use a gripper holding the sling is not required. This makes it possible, even threads in thicker Just stabbing textiles. For example. can several Layers of material, e.g. Carbon fiber mats, to be fixed. It is then worked only with a needle thread without bobbin thread. The height of the mats can be up to 40mm or more and does not have to be constant. This is, for example, in aircraft wings made of laminate material of the case. Here is important that through this type of stabilization without bobbin thread the carbon fiber mats are not damaged and that the height of the sewing material is not due to a knot is influenced by a bobbin thread. This can in a conventional lockstitch seam with upper thread and not guaranteed with this knotted bobbin thread become. The solidification of the puncture process stabilized layer material can when the mats preimpregnated are done through a heat process. Thus snares can be formed without the eye of the Completely piercing the needle through the sewing material.

Another advantage is the elimination of the knotting process. The gripper is superfluous. This will the thread spared. It only runs the required amount of thread through the eye. In contrast, are at a Lockstitching process with each loop larger thread lengths through the eye to pull by means of a gripper Guide the formed loop around a bobbin case to be able to. The gripper therefore pulls a thread length through the eye, which then when tightening (knotting) of the Upper thread is withdrawn again. Running this way in the conventional sewing thread sections many times through the eye until it finally becomes part of the suture Come to rest. The needle according to the invention allows avoidance such a thread load.

In addition, the needle according to the invention can be stable be formed. It is not a groove for a gripper required. Accordingly, the otherwise existing Cross-sectional weakening.

The needle according to claim 2 provides the same advantages. The opening of the eye extends with a pointed Angle through the needle body and is therefore relatively long. The circular cross section gives a good Thread guide and the thread is stabilized.

A particularly good suitability of the invention Needle for piercing thread in sewing material and looping, which on the return stroke ideally full training is maintained, when the eye in a very acute angle aligned with the needle longitudinal direction is. If the input and the output of the Ears are axially offset from each other, leaving out Side view seen the entrance and the exit of the Do not overlap the needle (i.e., it leaves a positive one) Axial distance between the entrance and exit of the eye) the thread is a good guide and runs with less Friction through the eye. Thus, a thread take in the Needle return stroke avoided.

The eye is preferably cylindrical, which also serves the purpose mentioned. The thread guide is also useful as long as possible Öhrlänge, the Length L of the eye is preferably greater than the thickness of the Needle.

A leading to the eye groove on the shaft allows the thread guide and the almost frictionless retraction of the thread in the sewing material when the depth of the gutter approximately coincides with the eye diameter or larger as this one. The thread trough can be a rectangular, have square or otherwise cross-section.

The eye is at its entrance at the of the thread trough bounded side preferably by an edge, the (slightly rounded and) on the outside of the needle is arranged. The edge serves to guide the thread during the needle return stroke and causes an avoidance of friction between the thread and the sewing material. This will be a takeaway the thread through the needle during the return stroke avoided.

The acute angle with which the eye against the needle longitudinal direction is inclined, is preferably smaller than 30 °. Better yet it is below 20 °, preferably below 15 °.

Next, it is considered appropriate, the distance set a value between the tip and the eye which is less than the length of the eye. The comparatively large eye length results in a good thread guide and the comparatively small distance between tip and Öhrausgang results in a large penetration depth of the thread. This is especially true if the distance between the Tip and the Öhrausgang is less than half the Öhrlänge.

The one provided in the vicinity of the exit of the eye Bump, which is used to clamp the thread in or on the Material used, preferably has a height at About 80% of the diameter of the eye is. In this way if the thread in the needle hole is well held, without too much increase in friction. It results Also, in comparison to a hollow needle a small Needle hole. This is, for example, for stapling or stabilizing Of carbon fiber mats advantage.

In addition, it is considered advantageous to the hump to keep relatively short in the needle longitudinal direction, wherein it is preferably shorter than 80% of the length of the eye.

Between the hump and the eye is preferably a rounded transition trained. This can also be sensitive Threads are processed gently. In particular Kevlar threads can be inserted without damage.

A long straight, a substantially constant Cross-section having shank allows the piercing of threads also in thick layers of material. For example. can with the needle according to the invention several layers of material Grooving be fixed, the layers are not pierced Need to become.

Further details of advantageous embodiments The invention are the subject of the drawing, the Description or dependent claims.

Fig. 1 die erfindungsgemäße Nadel in einer Draufsicht,

Fig. 2 die erfindungsgemäße Nadel in einer Seitenansicht,

Fig. 3 die Nadel nach den Figuren 1 und 2, in einer ausschnittsweisen Längsschnittdarstellung, in einem anderen Maßstab,

Fig. 4 die Nadel nach Figur 3, geschnitten entlang der Linie IV-IV in Figur 3,

Fig. 5 die Nadel nach den Figuren 1 und 2, in einer Vorderansicht mit Blickrichtung auf die Nadelspitze,

Fig. 6 die Nadel nach Figur 2, geschnitten entlang der Linie VI-VI in einem anderen Maßstab,

Fig. 7 eine erfindungsgemäße Nadel nach Beendigung eines Durchstechvorgangs vor Beginn des nächstfolgenden, in schematisierter, längs geschnittener Darstellung,

Fig. 8 die Nadel beim Ein- und Durchstechen eines Fadens durch Nähgut, vor ihrem unteren Totpunkt in längs geschnittener, schematisierter Darstellung,

Fig. 9 die Nadel beim Rückhub, in schematisierter, längs geschnittener Darstellung,

Fig. 10 die erfindungsgemäße Nadel nach dem Einstechen eines Fadens in Nähgut, unmittelbar vor dem nächsten Einstechvorgang, in längs geschnittener, schematisierter Darstellung,

Fig. 11 die Nadel beim Einstechen eines Fadens in Nähgut, vor ihrem unteren Totpunkt, in längs geschnittener, schematisierter Darstellung, und

Fig. 12 die Nadel beim Einstechen eines Fadens in Nähgut beim Rückhub, in schematisierter, längs geschnittener Darstellung.

In the drawing, an embodiment of the invention is illustrated. Show it:

1 shows the needle according to the invention in a plan view,

2 shows the needle according to the invention in a side view,

3 shows the needle of Figures 1 and 2, in a fragmentary longitudinal sectional view, on a different scale,

4 shows the needle according to FIG. 3, cut along the line IV-IV in FIG. 3, FIG.

5 shows the needle according to the figures 1 and 2, in a front view looking towards the needle point,

6 shows the needle according to FIG. 2, cut along the line VI-VI on a different scale,

7 is a needle according to the invention after completion of a piercing operation before the beginning of the next, in a schematic, longitudinal sectional view,

8 shows the needle during insertion and piercing of a thread through sewing material, before its bottom dead center in longitudinally sectioned, schematized representation,

9, the needle during the return stroke, in a schematic, longitudinal sectional view,

10 shows the needle according to the invention after the insertion of a thread into sewing material, immediately before the next piercing process, in a longitudinally sectioned, schematized representation,

11 shows the needle during insertion of a thread into sewing material, before its bottom dead center, in a longitudinally sectioned, schematic representation, and

12 shows the needle during the insertion of a thread into sewing material during the return stroke, in a schematic longitudinal section.

1 shows a needle 1 for piercing a thread 2 in sewing material 3 (Figures 7 to 12) illustrated. The Needle 1 has a shaft 4, which at one end in a Clamping part 5 and at its other, free end in one Head 6 passes. The head 6 contains an eye 7 with the length L, whose details in particular from the figures 2 and 3 emerge.

The eye 7 is formed by a cylindrical bore 8, the bore center axis 9 at an acute angle from about 13 ° to the shaft longitudinal direction determining Longitudinal axis 11 of the needle 1 is. The eye 7 and the bore 8 has an input 12 and an output 14 on. The entrance 12 is in the longitudinal direction the needle 1 by a near-peak limitation or Edge 15 and a tip-distant boundary or edge 16 limited. Between the bore 8 and the needle side 36, which is associated with the thread groove 27, results in a material area 15a, whose cross-section starting from the Edge 15 increases towards the top 21 out. An extension the bore 8, which touches the edge 15, results in the Needle side 36 an imaginary point of intersection 35. The distance between this intersection 35 and the bottom 28 of the needle groove 27 is larger than the bore diameter.

The output 14 is by a near-edge 17 and a tip-distant edge 18 limited. The entrance 12 and the output 14 are with respect to the axial direction of the Needle 1 spaced apart, i. between the edge 15 and the edge 18 is a positive distance exists. The input 12 and the output 14 overlap each other not, i. they are in axially different places arranged.

Approximately in the area of the opening 14 begins the Head 6 of the needle 1 to a tip 21 to taper. In near the tip 21, the needle 1, as Figure 4 illustrates, a circular cross section. The Tip 21 sets the position of the longitudinal central axis 11th firmly. With respect to this, the tip-side edge 17 is located the output 14 on a different side than the off-peak Edge 16 of the entrance 12. Despite low inclination against the longitudinal central axis 11, the bore 8 extends completely from one side of the longitudinal central axis 11 the other.

The bore 8 has a circular cross-section on and is cylindrical. The distance between the near-to-the-point Edge 17 of the output 14 and the tip 21 is preferably at most as large as the needle size and thus significantly shorter than the length of the bore. 8

The bore 8 goes to its tip distal edge 18th with a rounding into a hump 22 across, extending from a defined by the shaft 4 back 23 extends away. The height of the hump 22 is preferably too about 80% of the diameter of the bore 8 set.

The bump 22 preferably has a short straight Section 24, with a rounding in against the Longitudinal axis 11 inclined portion 25 passes, the at the eye 7 connects. At the remote from the eye 7 Side passes over the section 24 in an area 26, the is inclined towards the longitudinal central axis 11. The transitions are each rounded.

At the opposite side of the bump 22 shaft side is, as can be seen from Figures 2 and 3, a yarn channel 27 formed, extending from the chuck 5 to extends to the entrance 12 of the eye 7. The thread groove 27 has, as shown in Figure 6, an approximately square Cross-section on. The thread groove 27 is almost enough to the longitudinal central axis 11 of the shaft 4, by the way also preferably a substantially square Cross section has. Only in the area of the hump 22, the cross section is approximately rectangular, wherein the corners, i. the longitudinal edges of the shaft 4 throughout rounded.

With the needle 1 described so far becomes a Piercing or sewing process performed as follows:

In FIGS. 7 to 9, the piercing of the thread 2 is shown illustrated by the fabric 3 in different stages of work. FIG. 7 shows the sewing material 3, for example. through several layers of superimposed mats, For example. Carbon fiber mats, may be formed, with a ready trained loop 31. The needle 1 is longitudinal of the fabric 3 one step further and is now in the direction indicated by an arrow 32 on the Sewing material 3 to move. With the tip 21, the needle 1 opens a stitch hole and pierces the fabric 3. As Figure 8 illustrated, the thread lying on the fabric 3 2a are fixed by a holder 33. The needle 1 pulls on the downstroke with her eye 7 by means of the rounded Edge 18 the thread 2 through the opened stitch hole, wherein the thread 2 runs friction in the thread groove 27. Also, the bump 22 fixes the thread 2 on the fabric and prevents already lying on the fabric 3, piercing Thread 2a is tightened.

During the return stroke of the needle 1 in the in Figure 9 by a Arrow 34 designated direction, pushes the bump 22nd the thread 2 to the wall of the stitch hole, i. to the Sewing material 3 on. The formed loop 31 remains free stand below the fabric 3. The thread is free of play in the eye 7 and in the thread groove 27. He essentially runs stretched through the eye 7, wherein the round, in the thread running direction inclined bore 8 the thread a certain Gives stability. The edge 15 moves the thread 2 in Direction of the eye 7 and prevents contact between the thread 2 and the fabric 3 from. This promotes looping the needle according to the invention 1. The low friction between the thread and the round, in the thread running direction inclined eye 7, supports the looping additionally. No gripper is needed, which is the sling 31 holds and wrapped around a bobbin case. Thus is the penetration of the required thread 2 completely from a Coil pulled off. The loop 31 forming thread. 2 The eye 7 passes through only once. Is the sling 31 ready formed, so that several Nähgutschichten be stabilized. In this case, the needle according to the invention allows a controlled loop formation.

In Figures 10 to 12, the insertion of the thread 2 in a thicker fabric 3 illustrates that of the needle. 1 not pierced. The puncture process is otherwise correct largely consistent with the process described above. However, no loops or loops under formed the fabric 3, but the pierced Thread 2 remains stuck in the stitch hole. This condition is in Figure 10 for a previous insertion process illustrated. The needle 1 begins in Figure 10 with a Puncture direction according to arrow 32 a new stitching process. This is illustrated below in FIG. 11. How can be seen, pulls the eye 7 by means of the rounded edge 18 the thread 2 in the fabric 3 a. On the return stroke according to FIG. 12 in the direction of the arrow 34, the thread remains 2 stuck in the needle hole by holding it frictionally is. The comparatively lower friction between the thread 2 and the needle 1 allows these from the Stitch hole is pulled out in the direction of arrow 34, without taking the thread 2.

A needle for piercing or piercing a thread 2 in or through fabric 3 has a preferably cylindrical, tilted flat against the needle longitudinal direction long eye on, at the thread exit side a hump is adjacent. This serves to clamp one in sewing material pierced thread in the stitch hole. A needle 1 With such a construction allows a good low friction Guide the thread 2, allowing looping without additional Gripper is possible.

List of reference numbers:

1

needle

2,2a

thread

3

workpiece

4

shaft

5

chucking

6

head

7

eyelet

8th

drilling

9

Bore center

11

Longitudinal central axis

12

entrance

14

exit

15

tip near edge d. input

16

tip-distant edge d. input

17

near-peak edge of the exit

18

tip-distant edge of the exit

21

top

22

cusp

23

move

24

section

25

Area

26

Area

27

thread groove

28

ground

31

loop

32

arrow

33

holder

34

arrow

35

intersection

36

needle side

L

length

Claims (21)

1. Needle (1), in particular for inserting a thread (2) into sewing material (3) by machine,

   with a needle body, which is associated with an elongated blade (4) with a point (21), which has an eye (7) that is inclined at an acute angle to the longitudinal direction (11) of the blade and extends through this, wherein the eye (7) has an inlet (12) and an outlet (14), which respectively have a boundary (15, 17) close to the point and a boundary (16, 18) remote from the point and which are disposed on opposite sides of the blade (4) such that a positive distance remains between the boundary (15) of the inlet (12) close to the point and the boundary (18) of the outlet (14) remote from the point, and

   with a hump (22), which is formed on the needle body in the vicinity of the outlet (14) of the eye (7) and extends laterally away from the blade (4).
2. Needle (1), in particular for inserting a thread (2) into sewing material (3) by machine,

   with a needle body, which is associated with an elongated blade (4) with a point (21), which has an eye (7) that is inclined at an acute angle to the longitudinal direction (11) of the blade and extends through this, wherein the eye (7) has a circular cross-section, and

   with a hump (22), which is formed on the needle body in the vicinity of the outlet (14) of the eye (7) and extends laterally away from the blade (4).
3. Needle according to Claim 2, characterised in that the eye (7) has an inlet (12) and an outlet (14), which respectively have a boundary (15, 17) close to the point and a boundary (16, 18) remote from the point and which are disposed on opposite sides of the blade (4) such that a positive distance remains between the boundary (15) of the inlet (12) close to the point and the boundary (18) of the outlet (14) remote from the point.
4. Needle according to Claim 1 or 2, characterised in that the eye (7) is cylindrical in form.
5. Needle according to Claim 1 or 2, characterised in that the eye has a length (L) which is greater than the thickness of the needle.
6. Needle according to Claim 1 or 2, characterised in that on its blade (4) the needle (1) has a thread groove (27) leading to the eye (7), said groove (27) extending parallel to the longitudinal direction (11) of the needle.
7. Needle according to Claim 6, characterised in that the thread groove (27) has a depth which is essentially the same as the diameter of the eye (7).
8. Needle according to Claim 6, characterised in that the thread groove (27) has an essentially rectangular, preferably square, cross-section.
9. Needle according to Claim 1 or 2, characterised in that the edge (15) bordering the eye (7) at its inlet (12) towards the point (21) is disposed on the outside of the needle.
10. Needle according to Claim 9, characterised in that an imaginary extension of a hole (8) forming the eye (7) which touches the edge (15) forms an intersection (35) with a needle side (36), in which the needle groove (27) is provided, the distance between this intersection (35) and the base (28) of the needle groove (27) being greater than the diameter of the hole (8).
11. Needle according to Claim 1 or 2, characterised in that the acute angle between a central axis (9) of the hole of the eye (7) and the longitudinal central axis (11) is smaller than 30°.
12. Needle according to Claim 1 or 2, characterised in that the acute angle between a central axis (9) of the hole of the eye (7) and the longitudinal central axis (11) is smaller than 20°.
13. Needle according to Claim 1 or 2, characterised in that the acute angle between a central axis (9) of the hole of the eye (7) and the longitudinal central axis (11) is smaller than 15°.
14. Needle according to Claim 1 or 2, characterised in that between the point (21) and the eye (7) a distance is fixed which is less than the length of the eye (7).
15. Needle according to Claim 1 or 2, characterised in that between the point (21) and the eye (7) a distance is fixed which is less than half the length of the eye (7) and/or shorter than the needle thickness.
16. Needle according to Claim 1 or 2, characterised in that with respect to a line (longitudinal central axis 11) extending in the longitudinal direction of the needle (1) and passing through the point (21), the eye (7) is fully disposed on a different side at its inlet (12) than at its outlet (14).
17. Needle according to Claim 1 or 2, characterised in that the hump (22) has a height measured transversely to the longitudinal direction (longitudinal central axis 11) of the needle (1), which preferably amounts to less than 80% of the diameter of the eye (7).
18. Needle according to Claim 1 or 2, characterised in that the hump (22) has a length measured longitudinally to the longitudinal direction (longitudinal central axis 11) of the needle (1), which preferably amounts to less than 80% of the length of the eye (7).
19. Needle according to Claim 1 or 2, characterised in that a rounded transition area is formed between the hump (22) and the eye (7).
20. Needle according to Claim 1 or 2, characterised in that the blade (4) is straight in form and adjoining the hump (22) has a length with a constant cross-section which amounts to a multiple of the length of the eye.
21. Needle according to Claim 1 or 2, characterised in that the blade (4) has a rectangular, preferably a square, cross-section.

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