EP2181214B1 - Weft-thread insertion apparatus for a gripper weaving machine - Google Patents

Abstract

The invention proceeds from a gripper weaving machine, along which the gripper (6, 8) can be moved to and fro from a receiving position for a weft thread (4) into a transfer position or from the transfer position into a delivery position for the weft thread (4), wherein the gripper (6, 8) has a thread clamp with a movable clamping jaw (44) and a further clamping jaw (46). The movable clamping jaw (44) is prestressed into the clamping position by means of a prestressing spring and can be opened by means of magnet devices (20, 22; 24, 26; 28, 30) along the sliding track. The movable clamping jaw (44) is arranged on a lever (40). In order to make the gripper more reliable and to prevent rebound, in particular, during operation, it is proposed, furthermore, to arrange a permanent magnet (50) on the lever (40), which permanent magnet (50) prevents the clamping jaw (44) from rebounding out of the clamping position by interaction with an attracting counter magnet (52).

Description

Technical area

The invention relates to a weft insertion device with a gripper for a rapier according to the preamble of claim 1.

State of the art

In rapier looms of the weft thread is usually introduced by a Bringgreifer from one side into the shed and then - usually in about the middle of the shed - passed a Holgreifer, which then pulls the weft from the shed. In this case, gripping elements are formed in a gripping head in both grippers. The grippers move along along guide elements which are attached to the reed.

From the EP-A-0 690 160 a weft insertion device is known in which permanent magnets are provided for the gripping elements, which cause by appropriately set electromagnetic devices on the guide elements for the Bringgreifer and the Holgreifer an opening or closing the gripper heads controlled. However, this creates the problem that the electromagnets must be supplied to the guide elements with electrical power. This leads to considerable disadvantages, namely a heat generation and the complex routing of electrical supply cables to the reed. Another disadvantage is that a control device must be set up and switched, which has to fight at an increased weaving speed with synchronization problems or a complicated sensor mechanism must have. Although In the EP-A-0 690 160 Alternatively, it is also proposed to use permanent magnets as the magnetic force applying devices. However, it is proposed that these permanent magnets should be arranged in the vicinity of the Rückststotpunktposition on the weft insertion start page. Such a simple one-point transfer has proven to be disadvantageous.

In the EP-A-0 990 723 is proposed a solution in which the gripper equipped with permanent magnets is guided past a permanent magnet, whereby at this point the grippers are opened.

From the WO-A-99/60193 a gripper device is known in which the time-consuming electromagnets on the reed have already been overcome by the grippers each having an electric actuator, which is able to open and close the gripper head. It was proposed in the WO-A-99/60193 in that the actuator comprises an electromagnet, a piezoelectric element or a linear motor.

It is furthermore known from the prior art that a gripper device comprises two positive clamping jaws which are arranged on a gripper body. In this case, then the weft thread between the jaws is clamped feasible. When receiving the weft thread by the Bringgreifer, in the transfer of the weft thread from the Bringgreifer to the Holgreifer and the release of the weft thread from the Holgreifer the gripper device can be opened, whereby the weft thread is released. The opening is usually done by a movement of the upper jaw, so that the weft thread then rests freely on the lower jaw.

From the CH-A-556 930 It is known to form a gripper with a movable clamping part and a stationary abutment, wherein on the abutment a soft elastic pad is provided with a floating mounted on it, wear-resistant support member. The in the CH-A-556 930 proposed embodiment is characterized in that the support member held by its shape and the elasticity of the soft elastic pad (clamped) and thereby replacement or removal of the support member is made possible. The execution of CH-A-556 930 but also has disadvantages.

In the operation of such a gripper device has been found that the jaw can rebound when closing, especially if one of the jaws is provided with an elastic support. This is the Danger that the thread is not sufficiently clamped, that is taken along.

Presentation of the invention

The object of the invention is to improve a weft insertion device for a rapier of the type described above and to ensure a safe entrainment of the thread.

The object is achieved by a weft insertion device according to claim 1. The measures of the invention initially have the consequence that - especially at high operating frequencies - a bounce operation of the jaws is possible, whereby the thread is held securely and taken away. In addition, the production of the gripper is simple and can be carried out precisely and ensures safe, trouble-free and low-wear operation even at high speeds of the weaving machine. The weft insertion device according to the present invention is characterized in that the permanent magnets are arranged in Bringgreifer, Holgreifer and in the slide at the transfer station so that a thread from Bringgreifer on the Holgreifer by a section-wise, parallel moving the Bringgreifers and the Holgreifers handed over is, wherein the permanent magnets of the slide are attractively poled to the permanent magnets of the gripper. In order to increase the effect and thus the possible weaving speed and to design the weft insertion device more reliable, the invention proposes that Bringgreifer and Holgreifer each have two permanent magnets with opposite magnetic orientation and that along the slide at the receiving or dispensing positions each with two permanent magnets arranged opposite magnetic orientation.

Advantageous embodiments are defined in the dependent claims.

This effect according to the invention can be increased even further if, in each case, a permanent magnet is provided along the slideway at the receiving or dispensing positions between the two permanent magnets with opposite orientation is arranged with a magnetic alignment parallel to the slide (claim 2).

It is advantageous if a portion of the slide is connected to the reed (claim 3).

An advantageous implementation of the weft insertion is possible if the permanent magnets are arranged in Bringgreifer, Holgreifer and in the slide at the transfer station so that in parallel moving the Bringgreifers and Holgreifers the thread clamp of the Bringgreifers is opened while the thread clamp of the Holgreifers already closed (claim 4).

In principle, it is possible that the gripper both jaws are designed to be movable. Advantageously - because it is simpler - it is according to claim 5, but when the gripper, the further jaw is designed as a fixed jaw.

Particularly advantageous is the design of the gripper, characterized in that the lever is designed as a zwelarmiger lever and supported by a rotary joint, wherein on a lever arm, the movable jaw and the other lever arm of the permanent magnet to prevent the rebounding of the jaw from the clamping position is arranged (claim 6 ). According to claim 7, the biasing spring is formed as a torsion spring in the gripper.

A further advantageous embodiment is specified in claim 8. The gripper has a displaceable wedge means, by means of which the opening stroke of the movable jaw is adjustable.

The above-mentioned as well as the claimed and described in the following embodiments, according to the invention to be used elements are subject to their size, shape design, material usage and their technical conception no special conditions of exception, so that in The selection criteria known to the respective field of application can be used without restriction.

Brief description of the drawings

Figur 1

eine schematische Darstellung einer Schussfadeneintragvorrichtung mit dem Bringgreifer und dem Holgreifer vor dem Webblatt;

Figur 2

eine Detaildarstellung eines Greifers, hier des Holgreifers, gemäss Figur 1,

Figur 3

eine Darstellung mit detaillierter Darstellung zu einer der Schussfa- deneintragvorrichtung gemäss der vorliegenden Erfindung.

Embodiments of the invention will be described in more detail below with reference to schematic drawings, in which: FIG.

FIG. 1

a schematic representation of a weft insertion device with the Bringgreifer and Holgreifer before the reed;

FIG. 2

a detailed view of a gripper, here the Holgreifers, according to FIG. 1 .

FIG. 3

a representation with a detailed representation of one of the Schussfa- enteintragvorrichtung according to the present invention.

ways for carrying out the invention

In FIG. 1 a weft insertion device 2 of a rapier weaving machine for entering a weft thread 4 with a bringing gripper 6 and a Holgreifer 8 is shown. The Bringgreifer 6 brings the weft 4 from a receiving position outside of the reed 10 with the help of the Bringgreiferbandes 12 in a transfer position approximately in the middle of the reed 10. Also moves the Holgreifer 8 approximately in the middle of the reed 10, using the Holgreiferbandes 14, to take over the weft at the transfer position and pull on to the other side of the reed in the delivery position on. The Bringgreiferband 12 as well as the Holgreiferband 14 are driven by the Bringgreiferrad 16 and the Holgreiferrad 18. The representation of FIG. 1 FIG. 4 shows four permanent magnets in the gripper guide, namely, a permanent magnet 20 for the position when the carry gripper 6 is in the picking position for the weft, a permanent magnet 22 for the position when the carry gripper 6 is in the transfer position, a permanent magnet 24 for the position when the Holgreifer 8 is in the transfer position, and a permanent magnet 26 for the position when the Holgreifer 8 In the delivery position for the weft is. Appropriate Counter magnets 28 and 30 are located in the Bringgreifer 6 and Holgreifer 8, wherein these counter magnets are formed as permanent magnets.

The in FIG. 2 Holgreifer 8 shown in detail has a gripper body 32 on which on the one hand a fixed jaw 46 and on the other hand a device for the movable clamping jaw 44 is arranged. This device has a two-armed lever 39, one lever arm 41 of which forms the movable clamping jaw with an applied rubber damper 42. The other lever arm 40 has approximately at its end a retaining magnet 50 which cooperates with a retaining stop 52. The lever is biased by a torsion spring 34 in the clamping position of the jaws by a pressure transfer to the lever arm 41, in the present embodiment at point 36, approximately in the middle of the lever arm 41 is applied. The lever 39 is arranged in the region of the transition of the two lever arms 40 and 41 at a pivot 48.

If the Holgreifer 8 now passes past one of the permanent magnets 24 and 26, the movable jaw 44 is opened by the permanent magnet 30 is attracted by the respective permanent magnet 24 and 26 respectively. After passing the permanent magnet 24 or 26, the movable clamping jaw 44 is closed again and the thread is clamped. In order to avoid rebounding of the clamping jaw and thus loosening of the weft thread in the event of pinching, the magnet 50 is provided which prevents rebounding by its attractive interaction with the retaining stop 52. The Holgreifer 8 has in the present embodiment further comprises a sliding Kellmittel, by means of which the opening stroke of the movable jaw is adjustable. In the present embodiment, the bring gripper 6 is constructed according to the Holgreifer 8.

The preferred embodiment of the weft insertion will now be described. The two grippers 6 and 8 are each guided in the gripper guide 38, wherein the middle part of the gripper guide is arranged on the reed 10. In the gripper guide is in the area in which the weft thread in the receiving position is to be recorded, first of all a first permanent magnet 20 is arranged, which serves to open the thread clamp of the Bringgreifers 6 for receiving the weft thread 4. In the transfer area approximately in the middle of the weft insertion area, a second permanent magnet 22 is basically used to open the thread clamp of the delivery gripper 6 for discharging the weft thread to the harvesting grip 8. An in FIG. 1 Somewhere to the right permanent magnet 24 is used to open the thread clamp of the Holgreifers 8 for receiving the weft thread 4 by the Holgreifer 8, while another, in FIG. 1 shown right permanent magnet 26 for opening the thread clamp of the Holgreifers 8 for dispensing the weft thread 4 in the dispensing position next to the fabric edge is used.

In one embodiment of the present invention FIG. 3 the magnets are formed in a force-amplified design, in each case one in its polarity upward directed permanent magnet 158 or 162 and a downward polarity in its downside permanent magnet 160 or 164 in Bringgreifer 6 and in Holgreifer 8 a permanent magnet combination 142 in the gripper guide stand for the Bringgreifer 6 and a permanent magnet combination 150 in the gripper guide for the Holgreifer 8. In this case, the permanent magnet combination also consists of a respective upwardly directed in its polarity permanent magnet 144 and 152 and a downwardly directed in its polarity permanent magnet 148 and 156. The effect of the permanent magnet combinations 142 and 150 is still by the polarity parallel to the Direction of movement of the grippers 6 and 8 aligned permanent magnets 146 and 154 amplified by these permanent magnets 146 and 154 direct the magnetic flux.

LIST OF REFERENCE NUMBERS

2

Weft insertion device

4

weft

6

Bring gripper

8th

Holgreifer

10

reed

12

Bring rapier

14

Holgreiferband

16

Bringgreiferrad

18

Holgreiferrad

20

Permanent magnet in gripper guide, Bringgreifer in receiving position for the weft

22

Permanent magnet in gripper guide, Bringgreifer in transfer position

24

Permanent magnet in gripper guide, Holgreifer in transfer position

26

Permanent magnet in the gripper guide, Holgreifer in the dispensing position of the weft thread

28

Permanent magnet in Bringgreifer

30

Permanent magnet in Holgreifer

32

gripper body

34

torsion spring

36

Pressure transfer to lever

38

adjusting wedge

39

lever

40

lever arm

41

lever arm

42

rubber dampers

44

movable jaw

46

firm jaw

48

Swivel from the lever arm

50

Retention magnet

52

Retaining stop

142

Permanent magnet combination in gripper guide, centering gripper

144

Permanent magnet "up", Bringgreifer center

146

Permanent magnet "parallel", Bringgreifer center

148

Permanent magnet "down", Bringgreifer center

150

Permanent magnet combination In gripper guide, Holgreifer center

152

Permanent magnet "up", Holgreifer center

154

Permanent magnet "parallel", Holgreifer center

156

Permanent magnet "down", Holgreifer center

158

Permanent magnet in carry-gripper "up"

160

Permanent magnet in Bringgreifer "down"

162

Permanent magnet in Holgreifer "up"

164

Permanent magnet in Holgreifer "down"

Claims (8)

1. A weft thread insertion device (2) for a gripper weaving machine, with a sliding track and with a bringer gripper (6) and a fetcher gripper (8), wherein said grippers (6, 8) can be moved along said sliding track to and fro out of a pick-up position for a weft thread (4) into a transfer position or out of the transfer position into a drop-off position for the weft thread (4), the grippers (6, 8) having a thread clamp with a movable clamping jaw (44) and with a further clamping jaw (46), the movable clamping jaw (44) being prestressed in the clamping position by means of a presstressing spring and being openable by means of magnetic devices (20, 22; 24, 26; 28, 30) along a sliding track, the movable clamping jaw (44) being arranged on a lever (40), characterized in that, furthermore, a permanent magnet (50) is arranged on the lever (40) and prevents a rebound of the clamping jaw (44) out of the clamping position by means of cooperation with an attracting countermagnet (52), magnetic devices (20, 22; 24, 26) for opening the thread clamps being present along the sliding track in the pick-up and drop-off positions, the magnetic devices being designed as permanent magnets, the opening of the grippers (6, 8) being brought about by the movement of the grippers (6, 8) past the permanent magnets (20, 22; 24, 26) along the sliding track that the permanent magnets (28, 30; 20, 22, 24, 26) in the bringer gripper (6), in the fetcher gripper (8) and in the sliding track (38) at the transfer station are arranged so that a thread (4) can be transferred from the bringer gripper (6) to the fetcher gripper (8) by means of a partial parallel movement of the bringer gripper (6) and of the fetcher gripper (8), the permanent magnets (20, 22, 24, 26) of the sliding track having an attracting polarity with respect to the permanent magnets (28, 30) of the grippers (6, 8) that the bringer gripper (6) and fetcher gripper (8) in each case have two permanent magnets (158, 160, 162, 164) with an opposite magnetic orientation, and in that two permanent magnets (144, 148, 156, 152) with opposite magnetic orientation are arranged in each case along the sliding track in the pick-up and drop-off positions.
2. The weft thread insertion device as claimed in claim 1, characterized in that a permanent magnet (146, 154) with a magnetic orientation parallel to the sliding track is arranged in each case between the two permanent magnets with opposite orientation along the sliding track in the pick-up and drop-off positions.
3. The weft thread insertion device as claimed in claim 1 or 2, characterized in that a portion of the sliding track is connected to the reed (10).
4. The weft thread insertion device as claimed in anyone of claims 1 to 3, characterized in that the permanent magnets (28, 30; 20, 22, 24, 26) in the bringer gripper (6), in the fetcher gripper (8) and in the sliding track at the transfer station are arranged so that, during the parallel movement of the bringer gripper (6) and of the fetcher gripper (8), the thread clamp of the bringer gripper (6) is opened, while the thread clamp of the fetcher gripper (8) is already closed.
5. The weft thread insertion device as claimed in anyone of claims 1 to 4, characterized in that the further clamping jaw (46) of the grippers each are designed as a fixed clamping jaw (46).
6. The weft thread insertion device as claimed in anyone of claims 1 to 4, characterized in that the lever (39) of the grippers each are designed as a two-armed lever and is mounted by means of a rotary joint (48), the movable clamping jaw (44) being arranged on one lever arm (41), and the permanent magnet (50) for preventing the rebound of the clamping jaw (44) out of the clamping position being arranged on the other lever arm (40).
7. The weft thread insertion device as claimed in anyone of claims 1 to 6, characterized in that the prestressing spring of the grippers each are designed as a torsion spring (34).
8. The weft thread insertion device as claimed in anyone of claims 1 to 7, characterized by a displaceable wedge means (38) at the grippers, respectively, by means of which the opening stroke of the movable clamping jaw (44) can be set.

Images