EP0624671B1 - Thread retainer for a supply gripper and gripper loom with thread retainer - Google Patents

Description

The present invention relates to a thread holder for a rapier gripper of a rapier weaving machine according to the preamble of claim 1 and a rapier weaving machine with thread holder.

From FR-A-2 217 451 a thread clamp is known which consists of a lower part with a fastening hole and a needle-like part. The lower part has a groove with a semicircular cross-sectional contour, the sides of which converge slightly towards the end of the lower part. The lower part contains two pins, which are arranged at a distance from one another in the groove extending along the lower part and protrude from the groove.

The needle has a curved section at the front end in order to be able to form an inlet gap and a section with two through holes at the rear end. The needle is displaceably arranged on the pins transversely to the direction of action of the thread clamp and is held by a spring. In the rest position, the rear section of the needle lying in the groove is slightly raised and the needle is pressed by the spring against the base of the groove, so that the needle lies in the groove in the inlet area.

It proves to be a disadvantage that this thread clamp has a clamping point which is loaded by spring force, as a result of which the thread is stressed relatively strongly, so that the thread clamp proves to be completely unsuitable for fine threads.

• mit Spiel in der Bohrung liegt
  und
• mit seinem zurückgebogenen Endstück mit dem Rohr fest verbunden ist

und wobei das Endstück als Feder wirkt.In CH-A-508 075 a yarn holding device is described which has a tube piece with an inner wall and an obliquely cut running surface and a round rod with a bent-back end piece, the rod

• with play in the hole
  and
• is firmly connected to the pipe with its bent end piece

and the end piece acts as a spring.

This device has the disadvantages that the elements forming the gap are firmly connected and consequently an automatic adaptation of the gap cross section to the weft thread is not possible and that the weft thread is actively clamped due to the spring action of the end piece, so that thread breaks occur.

The purpose of the present invention is to remedy the stated disadvantage.

The invention, as characterized in claim 1, solves the problem of creating a thread holder for a bringer gripper, in which a weft thread is held without clamping action only by surface friction.

The advantages of the thread holder according to the invention can essentially be seen in the fact that the weft thread to be inserted is not exposed to any pressure load several weft threads can be picked up and that weft threads with different diameters to be inserted one after the other or simultaneously are held securely.

In one embodiment, a bearing point and a guide point spaced apart therefrom are arranged in the longitudinal extent of the second holding member outside the gap in order to align the surfaces of the first and second holding members delimiting the gap with one another. This has the advantages that the contour of the gap can be maintained and contact between the surfaces delimiting the gap can be avoided.

In a further embodiment, the first holding member has an elongated recess with a semicircular base and with a cross-sectional contour to be taken in the effective direction, which forms the surface delimiting the gap, and the second holding member is a needle with a constant, circular shape Cross-sectional contour, which forms the other surface delimiting the gap. Due to the increasing cross-sectional contour of the recess, an increasing wrap and, as a result, a larger friction surface can be generated in an advantageous manner.

It is advantageous if a shoulder is provided on the first holding member in order to limit the effective length of the gap. This allows multiple weft threads to be picked up in the gap.

In another embodiment, a device for actuating the second holding member is arranged on the first holding member in order to open the gap. This has the advantage that thread remnants and impurities are completely removed and cannot get into the tissue and that a perfect thread holder is always made possible.

It is advantageous if the device has an organ which is pivotably arranged on the first holding member and is operatively connected to the second holding member in order to open the gap and has a restoring element in order to readjust the gap. This allows the thread holder to be opened automatically within the weaving cycle. The function of the thread holder can advantageously be improved if a drive device, e.g. an electro-magnet for which the organ is intended.

It is also advantageous if the organ has guide means for the second holding member. This enables all-round guidance of the second holding member, which is movable in the longitudinal direction, to be achieved.

Fig.1

eine Ausführungsform eines erfindungsgemässen Fadenhalters in auseinandergezogener Darstellung;

Fig.2

einen Längsschnitt des in Fig.1 dargestellten Fadenhalters;

Fig.3

einen Schnitt entlang der Linie III - III in Fig.2;

Fig.4

einen Schnitt entlang der Linie IV - IV in Fig.2;

Fig.5

einen Längsschnitt gleich wie in Fig.8 einer anderen Ausführungsform eines erfindungsgemässen Fadenhalters;

Fig.6

ein Schnitt entlang der Linie VI - VI in Fig.5;

Fig.7

eine räumliche Darstellung eines Greiferkopfes mit einem Fadenhalter nach Fig.1 und

Fig.8

eine räumliche Darstellung des Greiferkopfes mit geöffnetem Spalt zum Reinigen des Fadenhalters.

The invention is explained below with reference to the accompanying drawings. Show it:

Fig. 1

an embodiment of a thread holder according to the invention in an exploded view;

Fig. 2

a longitudinal section of the thread holder shown in Figure 1;

Fig. 3

a section along the line III - III in Figure 2;

Fig. 4

a section along the line IV - IV in Figure 2;

Fig. 5

a longitudinal section the same as in Figure 8 of another embodiment of a thread holder according to the invention;

Fig. 6

a section along the line VI - VI in Figure 5;

Fig. 7

a spatial representation of a gripper head with a thread holder according to Fig.1 and

Fig. 8

a spatial representation of the hook head with an open gap for cleaning the thread holder.

Reference is made to Fig.1. The thread holder essentially consists of a first holding member 1, which is referred to below as the base body, a second holding member 2, which is referred to below as the needle, a retaining member 3, a sleeve 4 and a two-armed lever 5.

The base body 1 contains a section 6 which is formed at one end of the base body, a guide section 7 which is formed at a distance from the section 6 on the base body 1 and a holding section 8 which tapers towards the other end of the base body 1 is trained. It is particularly advantageous if the distance between section 6 and holding section 8 is at least 10 mm. A shoulder 9 is formed on the holding section 8, which forms a stop for the thread and prevents the thread from being pulled through in the longitudinal direction of the thread holder. A section 10 is formed in section 6, into which the needle 2 can be inserted at one end. The guide section 7 has a recess 11 into which the needle 2 can be inserted. In the holding section 8 there is a trough-shaped recess 12 which runs towards the end of the base body 1 and above which the needle 2 comes to rest.

The needle 2 has a circular cross section and has a pin 13. The sleeve 4 has a through hole 14, the cross-sectional shape of which is adapted to that of the pin. The retaining element is a leaf spring 3, which has a through hole 15 with a countersink and an elongated hole 16. The two-armed lever 5 has a pivot pin 17 which determines the pivot axis of the lever. The lever 5 is pivotally mounted on the base body 1. A pin 18 is attached to one lever arm and a tab 19 is formed on the other lever arm. A U-shaped recess 20 is formed on the base body 1 and is directed transversely to the needle axis.

As FIG. 2 shows, the needle 2 is supported at one end in the bore 10 serving as a bearing point in section 6, laterally guided and supported in the recess 11 serving as a bearing point and arranged at a distance from the inner surface of the recess 12. In order to achieve this arrangement, a single recess, for example a bore, is produced in the manufacture of the base body 1 according to the invention, which defines the contour of the bearing point 10 and the bearing point 11 and predetermines the contour of the recess 12. Through subsequent processing of the A gap 21 according to the invention is produced in recess 12.

The gap 21 is delimited on the one hand by the inner surface 22 of the recess 12 and on the other hand by the outer surface 23 of the needle 2. The arrangement of the needle 2 in the base body 1 described above forms a gap 21 with a curved cross-sectional shape, with a constant width in the direction of action of the thread holder and a continuously increasing cross-sectional contour, as can be seen from FIGS. 3 and 4. The gap width is at least 0.005 mm.

This inventive design of the recess 12 increases the wrap through the weft thread (not shown) to be drawn in and consequently the surface friction. This ensures that the weft is held securely.

The sleeve 4 is arranged on the pin 13. On this sleeve 4 is the leaf spring 3, which is penetrated by the pin 13 to guide the needle 2 with respect to the recess 12 of the thread holder. The leaf spring 3 is, on the other hand, fastened to the section 6 by means of a screw 24, the screw 24 simultaneously securing the needle 2 against being pulled out without hindering its mobility within the bore in the longitudinal extent.

In order to ensure a problem-free entry of a thread, the needle 2 has a bent section 25 at the free end, so that an essentially V-shaped inlet gap 26 is formed when the needle is installed.

The thread holder shown in Figure 5 has essentially the same basic structure as that above described thread holder, so that only the differently designed features are described below.

In this embodiment of the thread holder, the base body 31, the needle 32 and the retaining member 33 are modified.

In the above description, the needle has a circular cross section. However, it is also possible to use a needle with other cross-sectional shapes.

In a section 34 of the base body 31, a through-bore 35 is formed which is transverse to the direction of action of the thread holder and opens into a groove 36 on the upper side. The needle 32 has a section 37 bent at a right angle, which is arranged with play in the through bore 35, so that the needle 32 is movably mounted. The needle 32 is arranged and guided in a groove with a semicircular cross-sectional contour in the guide section 7.

The retaining element is a leaf spring 33 which is held on section 34 by means (not shown) in such a way that a downwardly curved end section 38 projects beyond section 35 in order to prevent engagement in the warp thread array when the hook head returns. At the other end, the leaf spring 33 has a section 39 which has a groove 40 which extends in the longitudinal direction of the leaf spring and has an approximately semicircular contour (FIG. 6).

The leaf spring 33 is designed such that the section 39 rests on both sides of the groove 40 on the guide section and there is a gap between the leaf spring 33 and the needle 32 in order to displace the needle 32 in the groove 40.

7 shows a hook head with a thread holder according to FIG. 1 and a weft thread 45 held therein. A hook body 47 known per se is attached to a band 46. A guide body 48 is mounted on this gripper body 42 on the side facing the reed (not shown). In addition to this guide body 48, the thread holder is arranged such that the weft thread 45 to be inserted is deflected on the one hand by the gripper body 47 and by the guide body 48 and on the other hand the tensile force acting on the weft thread is largely absorbed by this. As a result, the holding force to be applied is significantly lower and consequently fewer thread breaks occur, which is an advantage.

8 shows the gripper head according to FIG. 7 in a position before a weft insertion process. The thread holder is open in this position. For this purpose, an electromagnet 49 is provided, which is arranged in the rapier weaving machine in such a way that the tab 18 formed on the lever 5 comes into the force field of the electromagnet 49 and is attracted by it. The lever 5 is pivoted about the pivot pin 17 and the pin 18 is brought into operative engagement with the needle 2. As a result, the needle 2 is lifted out of the recess 12 against the force of the leaf spring 3. In this position, the thread holder is cleaned by a blowing device 51 and a suction device 52.

Claims (10)

1. A thread holder for a gripper of a gripper loom having a gap formed by a first (1) and a second (2) retention member, wherein the first and second retention members (1, 2; 31, 32) are disposed lying inside one another at least partly so that the faces (22, 23) of the first and second retention members limiting the gap (21) form a rectilinear gap (21) having a curved cross-sectional shape,
   characterised in that the second retention member (2; 32) is movably disposed in the first retention member (1; 31) in its longitudinal extension so that the faces (22, 23) limit a gap (21) having a width remaining constant in the effective direction of the thread holder and having a cross-sectional contour continuously increasing in the effective direction, in which gap an inserted weft thread (45) is held by frictional force.
2. A holder according to Claim 1,
   characterised by a bearing point (10; 36, 37) and a guide point (11) spaced therefrom, which are disposed in the longitudinal extension of the second retention member (2; 32) outside the gap (21) in order to align the faces (22, 23), limiting the gap (21), of the first and second retention member with respect to one another.
3. A holder according to one of Claims 1 or 2,
   characterised in that the first retention member (1, 31) has a long recess (12) having a semi-circular base and having a cross-sectional contour increasing in the effective direction, which forms the one face (22) limiting the gap (21),
   and in that the second retention member is a needle (2; 32) having a constant cross-sectional contour, which forms the other face (23) limiting the gap (21).
4. A holder according to one of Claims 1 to 3,
   characterised in that a shoulder (9) is provided at the first retention member (1) in order to limit the effective length of the gap (21).
5. A holder according to one of Claims 1 to 4,
   characterised by a mechanism (3, 5; 33) for operating the second retention member, which is disposed on the first retention member (1, 31), in order to open the gap (21) for the purpose of cleaning and respectively to reset it.
6. A holder according to Claim 5,
   characterised in that the mechanism has a member (5) which is pivoted on the first retention member (1, 31) and can be brought into active communication with the second retention member (2, 32) in order to open the gap (21) and has a restoring member (3; 33) in order to reset the gap (21).
7. A holder according to Claim 6,
   characterised in that the restoring member (3; 33) is elastically deformable.
8. A holder according to one of Claims 6 or 7,
   characterised in that the member (3,; 33) has guide means (40) for the second retention member (2, 32).
9. A holder according to one of Claims 5 or 6,
   characterised by a driving mechanism (49) for the member (5).
10. A gripper loom having a thread holder according to one of Claims 1 to 9,
    characterised by a cleaning device (51, 52) for the thread holder.

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