EP1069226A1 - Sewing machine needle with improved loop formation - Google Patents

Abstract

A sewing machine needle has an eye (7) at an acute angle, e.g. less than 15 degrees , with the needle axis (11) and that is long enough so that there is some distance between opposite edges (15,18) of the entry (12) and exit (14). Near the exit (14) is a lateral hump (22), which is blended into the needle outline and has a height preferably less than 80% of the diameter of the eye (7). An Independent claim is also included for a needle with an angled eye of circular cross-section and a lateral hump near the eye exit.

Description

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

When sewing material, a thread, the so-called Upper thread, by means of a needle that is close to her Is provided with an eye, continuously through the Stitched material. Each time the needle is withdrawn results in a noose by a noose gripper captured and through which another thread, the so-called Bobbin thread. One arises from upper and Existing thread. To the bobbin thread through the To be able to pull the noose, the noose is with the Loop gripper grasped and enlarged by one Pull the bobbin case around, in which the bobbin thread located. For this purpose, the loop hook is first upper thread tightened, which then pulled back through the eye becomes. The upper thread therefore passes through the eye of the needle many times and is heavily used.

In addition, there are sewing processes in which the Upper thread is stuck in or through the material without that a gripper the thread and the loop formed holds when pulling back the needle. Should be reliable here form a loop, the thread must be rubbed be held between him and the material.

From US-PS 3,523,510 is a tufting needle for known the carpet manufacture, which serves a staple fiber yarn to pierce through a base fabric and with the To form staple yarn loops. The tufting needle for this purpose has an approximately cylindrical shaft which is pointed at one end. Is near the top a funnel-shaped eye is formed at an angle to the central axis of the needle. An air duct is provided in the tufting needle with which the eye can be pressurized with compressed air. In connection at the eye are opposite each other on both Flat channels formed on the sides of the tufting needle, whose depth is less than the smallest diameter of the Öhrs. Following the eye, the shaft is on the clamping side cylindrical and conical towards the tip. The inclination of the eye to the longitudinal axis is approximately 30 °.

The loop formation is with this needle by the Effect of the compressed air introduced into the eye supports. There are no other means of holding the thread loop evident.

Another tufting needle is known from EP 0187925. This starts from a tubular body, which is cut obliquely to form a tip. On the opposite side of the slope is the tubular one Basic body also opened so that a through the open interior running thread at the slant arranged mouth surface of the tubular base body can leak. The eye thus formed has an oval Cross-section due to the tubular base body given deformation changes along the eye. On the open side of the tubular body opposite side is the tubular base body flattened so that an indentation or groove is formed is.

Another tufting needle is from DE 2834738 C2 known. This needle has a flat needle body Cross-section based on one embodiment almost unchanged to an eye that extends across directed to the longitudinal axis of the needle and elongated oval is. A gutter leads to the eye, which is considerable is flatter than the thread. The length of the eye is at this Embodiment about the size of the mouth of the eye on the two corresponding opposite one another Needle sides.

In a modified, from the mentioned DE 2834738 C2 previously known embodiment (FIG. 5 of the patent specification) is a tufting needle with an approximately spoon-shaped Head known. A thread groove extends along the shaft, whose depth is less than the thread thickness and essential is less than the eye width. The eye is oval trained and extends across the tufting needle. On the opposite side of the thread gutter is in Area of the eye and a subsequent shaft area a deflection is provided.

Similar tufting needles can be found in 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 interact with a thread gripper is set up. The sewing needle serves the upper thread to pierce through the material, the forming The loop is then held and enlarged by a thread gripper 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 is completely in the thread trough runs. The eye extends on one arcuate path across the needle and expanding thereby funnel-shaped. The ear cross-section is fixed oval. Immediately after the eye is at the of facing away from the tip and opposite the thread groove A trough is provided for the hook or gripper, who works with the needle.

Proceeding from this, it is an object of the invention to To create a needle with improved looping.

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

The needle according to the invention has a long thread well-leading eye and one adjacent to the eye exit Hump to clamp the thread in the material. The eye is through a preferably straight passage formed at an acute angle against the longitudinal direction of the needle is inclined. This results in a low friction of the through the eye of running thread on the eye and a good one Thread guidance.

In connection with the arranged on the needle back The thread is pulled back through the eye of the needle and thus a contraction of the needle during the puncturing process generated thread loop avoided. With the The needle according to the invention can therefore produce a loop which, when retracting the needle in its ideal full training is maintained. The stake a gripper that holds the sling is not required. This makes it possible to thread even thicker ones Just stab textile. E.g. can several Layers of material, e.g. Carbon fiber mats to be fixed. It then only one upper thread without bobbin thread is used. The height of the mats can be up to 40mm or more and does not have to be constant. This is the case, for example, with aircraft wings made of laminate material. Here is significant that through this type of stabilization the carbon fiber mats will not be damaged without the bobbin thread and that the height of the sewing material is not due to a knot is influenced with a bobbin thread. This can with a conventional lockstitch seam with upper thread and not ensured with this knotted bobbin thread become. The solidification of the puncture Stabilized layer material can be used if the mats are pre-impregnated are done through a heating process. Consequently can be formed without the eye of the The needle sticks completely through the material.

Another advantage is the elimination of the knotting process. The gripper is superfluous. This will the thread is spared. Only the required amount of thread is running through the eye. In contrast, one Lockstitch process with each loop formation longer thread lengths to pull through the eye to by means of a gripper pass the loop around a bobbin case to be able to. The hook therefore pulls a thread length through the eye, which then when tightening (knotting) the Upper thread is withdrawn again. Run this way Thread sections often in the conventional sewing process through the eye until it is finally part of the seam to the Come calm. The needle according to the invention allows this to be avoided 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 one is dropped Cross-sectional weakening.

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

A particularly good suitability of the invention Needle for inserting thread into the material and forming loops, ideally in full training on the return stroke is preserved if the eye is in one very acute angle to the longitudinal direction of the needle is. If the input and the output of the Öhrs are axially offset from each other, so that from Viewed from the side, the entrance and exit of the Do not overlap the needle (i.e. a positive one remains 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 with the Needle return stroke avoided.

The eye is preferably cylindrical, what also serves the stated purpose. The thread guide It is also useful to have the largest possible eye length, whereby the Length L of the eye is preferably greater than the thickness of the Needle.

A groove on the shaft leading to the eye enables the thread guide and the almost frictionless drawing of thread into the material when the depth of the gutter approximately matches or is larger than the eye diameter than this. The thread channel can be a rectangular, have square or other cross-section.

The eye is at the entrance of the thread gutter remote side preferably bounded by an edge, the (somewhat rounded and) on the outside of the needle is arranged. The edge serves to guide the thread during the needle return stroke and prevents friction between the thread and the sewing material. This will take you away of the thread avoided by the needle during the return stroke.

The acute angle with which the eye against the longitudinal direction of the needle is preferably smaller than 30 °. Even better, it is below 20 °, preferably below 15 °.

It is also considered appropriate to use the distance to 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 good thread guidance and the comparatively small distance between the tips and eye exit results in a large penetration depth of the thread. This is especially true if the distance between the Tip and the eye exit is less than half the eye length.

The one provided in the vicinity of the exit of the eye Bump used to clamp the thread in or on the Serves material, preferably has a height that at about 80% of the diameter of the eye. In this way the thread is held firmly in the stitch hole, without increasing the friction too much. It results also a small compared to a hollow needle Taphole. This is, for example, for stapling or stabilizing of carbon fiber mats an advantage.

The cusp is also considered beneficial to keep relatively short in the longitudinal direction of the needle, whereby it is preferably shorter than 80% of the length of the eye.

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

A long straight one, essentially constant Cross-section shaft allows piercing of threads even in thick layers of material. E.g. can with the needle according to the invention through several layers of material Plunging should be fixed, the layers not being punctured Need to become.

Further details of advantageous embodiments the invention are the subject of the drawing, the Description or subclaims.

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.

An exemplary embodiment of the invention is illustrated in the drawing. Show it:

1 is a plan view of the needle according to the invention,

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

3 shows the needle according to FIGS. 1 and 2, in a partial longitudinal section, on a different scale,

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

5 shows the needle according to FIGS. 1 and 2, in a front view looking towards the needle tip,

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

7 shows a needle according to the invention after the end of a piercing process before the start of the next one, in a schematic, longitudinally sectioned illustration,

8 shows the needle when a thread is being pierced and pierced by material, before its bottom dead center in a longitudinally sectioned, schematic representation,

9 the needle during the return stroke, in a schematic, longitudinally sectioned illustration,

10 the needle according to the invention after a thread has been inserted into the sewing material, immediately before the next insertion process, in a longitudinally sectioned, schematic representation,

Fig. 11 shows the needle when piercing a thread in the material, before its bottom dead center, in a longitudinally sectioned, schematic representation, and

Fig. 12 shows the needle when piercing a thread in the material during the return stroke, in a schematic, longitudinal section.

In Figure 1 is a needle 1 for piercing a thread 2 illustrated in material 3 (Figures 7 to 12). 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 merges. The head 6 contains an eye 7 with the length L, the details of which can be seen in particular from FIGS. 2 and 3 emerge.

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

The exit 14 is through a near edge 17 and delimits a distal edge 18. The entrance 12 and the output 14 are with respect to the axial direction of the Needle 1 spaced apart, i.e. between the edge 15 and the edge 18 there is a positive distance. The input 12 and the output 14 overlap not, i.e. they are in axially different places arranged.

Approximately in the area of the opening 14 begins Taper head 6 of needle 1 to a tip 21. In near the tip 21 the needle 1, as illustrated in FIG. 4, a circular cross section. The Tip 21 sets the position of the longitudinal central axis 11 firmly. The tip-side edge 17 lies with respect to this of the output 14 on a different side than the distal one Edge 16 of the entrance 12. Despite a slight incline the bore 8 extends against the longitudinal central axis 11 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 tips Edge 17 of the exit 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 at its edge 18 remote from the tip with a curve into a hump 22 that extends from a back 23 defined by the shaft 4 extends away. The height of the hump 22 is preferably too set about 80% of the diameter of the bore 8.

The bump 22 preferably has a short straight line Section 24, which has a rounding in one against the The longitudinal central axis 11 passes over the inclined region 25 which the eye 7 connects. At the distance from the eye 7 Section 24 merges into an area 26 which is inclined against the longitudinal central axis 11. The transitions are rounded in each case.

On the shaft side opposite the hump 22 is, as can be seen from Figures 2 and 3, a thread groove 27 formed, which are from the clamping part 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 sufficient up to the longitudinal central axis 11 of the shaft 4, the rest also preferably a substantially square one Has cross section. Only in the area of the hump 22, the cross section is approximately rectangular, wherein the corners, i.e. the longitudinal edges of the shaft 4 continuously are rounded.

With the needle 1 described so far, a Grooving or sewing is carried out as follows:

7 to 9 is the piercing of the thread 2 illustrated by the sewing material 3 in different working stages. Figure 7 shows the sewing material 3, for example. through several layers of mats on top of each other, For example, carbon fiber mats can be formed with a finished trained loop 31. The needle 1 has lengthways of the sewing material 3 moves one step further and is now in the direction indicated by an arrow 32 on the Material 3 too moved. The needle 1 opens with the tip 21 a stitch hole and pierces the sewing material 3. As in FIG. 8 illustrates, the thread lying on the sewing material 3 2a are fixed by a holder 33. The needle 1 pulls on the downward stroke with her eye 7 by means of the rounded Edge 18 thread 2 through the open stitch hole, the thread 2 runs with little friction in the thread groove 27. The hump 22 also fixes the thread 2 to the material to be sewn and prevents stabs that are already sticking to the material 3 Thread 2a is drawn.

During the return stroke of the needle 1 in the in FIG Direction indicated by arrow 34, the hump 22 presses thread 2 to the wall of the taphole, i.e. to the Material 3 on. The loop 31 formed remains free stand below the material 3. The thread is free of play in the eye 7 and in the thread groove 27. It runs essentially stretched through the eye 7, being round, in the thread running direction inclined hole 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 sewing material 3. This promotes loop formation the needle of the invention 1. The low friction between the thread and the round one, in the thread running direction inclined eye 7, supports loop formation additionally. No gripper is needed to hold the sling 31 holds and wraps around a bobbin case. Consequently the thread 2 is completely inserted by one when the stitch is inserted Coil removed. The thread 2 forming the loop 31 passes through eye 7 only once. The loop 31 is finished several layers of material are stabilized. The needle according to the invention enables this a controlled loop formation.

In FIGS. 10 to 12 the thread 2 is pierced illustrates a thicker sewing material 3, the needle 1 is not punctured. Otherwise the puncture process is correct largely with the process described above. However, no loops or loops are under the sewing material 3, but the pierced Thread 2 gets stuck in the stitch hole. That state is in Figure 10 for a previous puncture illustrated. The needle 1 begins in FIG. 10 with a Puncture direction according to arrow 32 a new stitching process. This is illustrated below in FIG. 11. How visible, the eye 7 pulls by means of the rounded edge 18 the thread 2 into the sewing material 3. On the return stroke 12 in the direction of arrow 34, the thread remains 2 stuck in the tap hole by holding it frictionally is. The comparatively lower friction between the thread 2 and the needle 1 allows them from the The stitch hole is pulled out in the direction of arrow 34, without taking the thread 2.

A needle for inserting or piercing a thread 2 in or by sewing material 3 has a preferably cylindrical, inclined flat against the longitudinal direction of the needle long eye with a hump on the thread exit side is adjacent. This is used to clamp one in the material stitched thread in the stitch hole. A needle 1 with such a structure allows a good low-friction Guiding the thread 2, so that loop formation without additional Gripper is possible.

List of reference numerals:

1

needle

2.2a

thread

3rd

Material

4th

shaft

5

Clamping part

6

head

7

Eye

8th

drilling

9

Central bore axis

11

Longitudinal central axis

12th

entrance

14

output

15

edge close to the tip d. Input

16

distant edge d. Input

17th

edge of the exit near the point

18th

tip distant edge of the exit

21

top

22

Hump

23

move

24th

section

25th

Area

26

Area

27

Thread gutter

28

ground

31

loop

32

arrow

33

holder

34

arrow

35

Intersection

36

Needle side

L

length

Claims (21)

Needle (1), in particular for mechanically inserting a thread (2) into the material (3), with a needle body, to which an elongated shaft (4) with a tip (21) belongs, which has an eye (7) which extends through it at an acute angle to the longitudinal direction of the shaft (11), the eye (7) has an inlet (12) and an outlet (14), each of which has a border (15, 17) near the tip and a border (16, 18) remote from the tip and which are arranged on opposite sides of the shaft (4) such that between the near-tip boundary (15) of the inlet (12) and the distant boundary (18) of the outlet (14) remain a positive distance, and with a hump (22) formed on the needle body in the vicinity of the outlet (14) of the eye (7) and extending laterally away from the shaft (4). Needle (1), in particular for mechanically inserting a thread (2) into the material (3), with a needle body, to which an elongated shaft (4) with a tip (21) belongs, which has an eye (7) which extends at an acute angle inclined to the longitudinal direction of the shaft (11), the eye (7) has a circular cross section, and with a hump (22) formed on the needle body in the vicinity of the outlet (14) of the eye (7) and extending laterally away from the shaft (4). Needle according to claim 2, characterized in that the eye (7) has an entrance (12) and an exit (14) which each have a boundary close to the tip (15, 17) and have a boundary (16, 18) remote from the tip and the opposite sides of the shaft (4) are arranged so that between the tip Limitation (15) of the entrance (12) and the distant Limitation (18) of the output (14) a positive distance remains. Needle according to claim 1 or 2, characterized in that that the eye (7) is cylindrical. Needle according to claim 1 or 2, characterized in that that the eye has a length (L) that is greater than the thickness of the needle. Needle according to claim 1 or 2, characterized in that that the needle (1) on its shaft (4) one to the Öhr (7) leading thread groove (27), the Channel (27) extends parallel to the longitudinal direction of the needle (11). Needle according to claim 6, characterized in that the thread groove (27) has a depth that is essentially corresponds to the diameter of the eye (7). Needle according to claim 6, characterized in that the thread groove (27) has a substantially rectangular, preferably has a square cross section. Needle according to claim 1 or 2, characterized in that that the eye (7) at its entrance (12) to the Point (21) bounding edge (15) on the outside of the needle is arranged. Needle according to claim 9, characterized in that an imaginary extension touching the edge (15) a bore (8) which forms the eye (7) with a needle side (36), in which a needle groove (27) is provided, gives an intersection (35), the distance between this intersection (35) and the bottom (28) of the needle groove (27) is larger than the diameter of the bore (8). Needle according to claim 1 or 2, characterized in that that the acute angle between a bore center axis (9) of the eye (7) and the longitudinal central axis (11) is less than 30 °. Needle according to claim 1 or 2, characterized in that that the acute angle between a bore center axis (9) of the eye (7) and the longitudinal central axis (11) is less than 20 °. Needle according to claim 1 or 2, characterized in that that the acute angle between a bore center axis (9) of the eye (7) and the longitudinal central axis (11) is less than 15 °. Needle according to claim 1 or 2, characterized in that that between the tip (21) and the eye (7) a distance is specified that is less than the length of the eye (7). Needle according to claim 1 or 2, characterized in that that between the tip (21) and the eye (7) a distance is set that is less than half Length of the eye (7) and / or less than the needle size is. Needle according to claim 1 or 2, characterized in that that the eye (7) with its entrance (12) with respect one extending in the longitudinal direction of the needle (1), line passing through the tip (21) (longitudinal central axis 11) arranged entirely on another side is as with its output (14). Needle according to claim 1 or 2, characterized in that that the bump (22) is transverse to the longitudinal direction (Longitudinal central axis 11) of the needle (1) height to be measured has, which is preferably less than 80% of the diameter of the eye (7). Needle according to claim 1 or 2, characterized in that that the bump (22) is longitudinal to the longitudinal direction (Longitudinal central axis 11) of the needle (1) to be measured Length, which is preferably less than 80% of the length of the eye (7). Needle according to claim 1 or 2, characterized in that that between the hump (22) and the eye (7) a rounded transition is formed. Needle according to claim 1 or 2, characterized in that that the shaft (4) is straight and following the hump (22) a length with constant Cross section that is a multiple of the eye length. Needle according to claim 1 or 2, characterized in that that the shaft (4) is rectangular, preferably has a square cross section.

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