EP1672104B1 - Gripper device for an axminster weaving loom - Google Patents

Abstract

A gripper device for an Axminster loom comprises first and second jaws (19,21), each with a gripping surface for firmly clamping a pile thread; and a hinge (32), tiltably connecting the two clamps together, defining a tilting axis (33) and having at least one cylindrical bearing surface (38, 47, 48), on which one of the jaws is tiltably mounted with a similarly cylindrical counter-bearing surface (39, 49, 51). An independent claim is included for a variant of the the gripper device, in which a bearing rib (43) is arranged concentrically to a catch (36) on one of the jaws (19, 21) and coordinated with an annular groove (44) in the other jaw.

Description

For the manufacture of carpets and for the production of other textile fabrics, Axminster weaving is known. Corresponding weaving machines, whose principal function is to be found in the reference "Carpet Manufacture" (Carpet Production Geoffrey H. Crawshaw, WRONZ Developments, Private Bag 4749, Christchurch, New Zealand) The weaving machine operates with three warp thread groups, to which corresponding shafts assigned. Pre-cut pile threads are guided between the warp threads by means of gripper devices seated on a bar and fixed there by the weft threads.

Axminster weaving machines were considered to be less productive for a long time. However, with the introduction of electronically controlled jacquard technology, Axminster weaving machines have not only gained a high degree of flexibility, but have also greatly increased their productivity.

The gripper devices of the Axminster weaving machines are of particular importance. They are usually controlled by a so-called lock. It must be ensured that the individual grippers have a controlled and desired clamping effect. If the clamping effect is not sufficient, individual pile threads may slip or get lost, which of course is unacceptable.

Grippers for Axminster weaving machines are eg from the GB-A 876780 known. The grippers are formed by two jaws, which are mounted together like a pair of pliers. The grippers are designed to be extremely narrow in order to fit between the small intermediate spaces between the warp threads. The jaws are held together by a rivet, which forms a joint for the jaws.

From the above GB-A 876780 , of the GB-A 1635670 , of the GB-A 2060280 and the DE-A-2164222 are more grippers with two jaws known which are pivotally mounted together. For this purpose, a jaw on a bearing opening, which of a journal of the other jaw is penetrated. The bearing pin is deformed at its end, so that it serves as a fastening rivet.

The GB-A 441938 discloses a gripper with a central pin serving as a journal, in which a conical screw is screwed or a cone is inserted to widen the upper edge of the hollow pin and to secure the jaws.

Another concept pursues the US-A 1816938 according to which a clamping jaw has a bearing surface with a central pin and the other clamping jaws an opening which receives the pin. In order to hold one jaw on the other jaws, a bearing with three screws bearing disc is provided on one of the jaws.

Such joints have a certain radial play. This has a direct influence on the clamping action of the gripper. In Axminster looms several grippers are driven by one and the same actuator. Different clamping effects due to radial play different grippers then causes individual grippers can easily grip the thread, while others do not grab the thread, because the jaws do not close sufficiently. This problem is then often solved in that the actuator is adjusted so that even the biggest game having gripper completely close. But this has the consequence that in the course of the manufacturing process with grippers working initially without play, due to the strong Closing pressure game sets or in extreme cases, the grippers tend to break.

On this basis, it is an object of the invention to provide a gripper device that works on the one hand precise and on the other hand reliable.

This object is achieved with the gripper device according to claim 1.

The gripper device according to the invention has an improved joint. This has a cylindrical bearing portion on which one of the clamping jaws is pivotally mounted with a likewise cylindrical abutment portion. The two cylindrical surfaces serving for storage can be both continuous annular surfaces and discontinuous surfaces, wherein recesses provided in the surfaces, for example the oil retention or the dirt receptacle, can serve.

Compared with gripping devices with, for example, conical bearing bores which are held together by a countersunk rivet, the gripping device according to the invention, provided with a cylindrical bearing device, has a more precise radial guidance of the two clamping jaws. The reduced radial clearance leads to a uniform closing of all gripper devices that are actuated by the same cam curve. Accordingly, the gripper devices can close precisely. The overload of individual gripper devices can be avoided, so that the risk of jaw breakage is reduced to a minimum or completely excluded. The clamping effect The single gripper is almost identical. The looms can be optimally adjusted.

According to the invention, the cylindrical bearing surface is formed on one of the clamping legs and the counter-bearing surface on the respective other clamping leg. In this case, the hinge has an extension which is arranged concentrically to the pivot axis of the joint and engages through a bearing opening of one of the clamping jaws. Preferably, the extension is formed on the like also referred to as "base" jaws, while the bearing opening is arranged in the called "lever" jaws. The extension has a cylindrical outer surface, which serves as the cylindrical bearing surface in a first embodiment. The likewise cylindrical abutment surface can be formed by the wall of the bearing opening. To secure the two jaws together, the extension can be deformed in the axial and / or radial direction. Its upper free edge then forms a rubble edge. This ring can be closed annularly around the circumference or can only be urged outwards in sections in the form of individual caulking sections.

The extension is preferably integral with one of the jaws, that is formed seamlessly from the same material as this. Alternatively, it may be connected to the jaw, for example, by a welding operation or another connection process. In any case, he is with respect to the jaws, with which he is firmly connected, precisely arranged and play-free connected to this, which is the basis for a precise storage of the other jaw is created.

According to the invention, a bearing rib is arranged concentrically to the extension. This can then be formed as an annular, formed on an otherwise flat surface survey, which is associated with a arranged in the other jaws annular groove. The bearing rib can serve for the axial and / or radial mounting of the jaws together. Serves them the axial bearing their height is at least slightly greater than the depth of the annular groove. In this case, the flat annular surface of the annular rib serves as an axial bearing and bearing surface, while remaining a gap between the clamping jaws. In this embodiment, a precise axial bearing is given at the same time low friction and good oil retention.

Alternatively or additionally, the bearing rib can serve for radial mounting. In this case, the cylindrical bearing surface is formed by the inner or outer cylindrical flank of the bearing rib. The corresponding abutment surface is then formed by the associated annular groove wall of the bearing or annular groove.

In this embodiment, the bearing device is formed largely independently of the extension. If this caulked or compressed, to secure the two jaws captive to each other, the radial and / or axial bearing is retained by the principle not to be deformed bearing rib and the associated annular groove.

The gripper according to the invention is also distinguished in a preferred embodiment by the fact that the cylindrical bearing surface has an axial length to the joint axis of at least one fifth to one quarter of the total thickness of the jaw. This corresponds to half the height of the projection, which may be formed on one of the jaws and serves to support the jaws together. While one half of the height of the projection of the storage serves, the other half is provided with a flared, conical edge. The inclination of the conical surface to the cylindrical surface is up to 45 °. A separate rivet is not available. Rather, the jaws are connected by embossing. Manufacturing tolerances and tolerances due to wear during operation do not affect due to the presence of the cylindrical bearing surface in the radial direction.

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

Figur 1

eine Axminster-Webmaschine in stark schema- tisierter Darstellung,

Figur 2

die Axminster-Webmaschine nach Figur 1 in ei- ner ausschnittsweisen Darstellung zur Veran- schaulichung der Funktion ihrer Greiferein- richtung,

Figur 3

die Greifereinrichtung der Axminster-Webma- schine nach Figur 1 und 2 in gesonderter Dar- stellung in Seitenansicht,

Figur 4

die Greifereinrichtung nach Figur 3 mit von- einander getrennten Klemmbacken zur Veran- schaulichung ihres Gelenks in Seitenansicht der Klemmbacken,

Figur 5

einen Klemmbacken der Greifereinrichtung nach Figur 3 und 4 in perspektivischer, teilweise geschnittener Darstellung und

Figur 6

die Greifereinrichtung nach Figur 3, geschnit- ten entlang der Linie VI-VI in ausschnittswei- ser Darstellung und einem anderen Maßstab.

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

FIG. 1

an Axminster loom in a highly schematic representation,

FIG. 2

the Axminster loom behind FIG. 1 in a detailed presentation for the visualization of the function of their gripper device,

FIG. 3

the gripper device of the Axminster weaving machine FIG. 1 and 2 in a separate representation in side view,

FIG. 4

the gripper device after FIG. 3 with separate clamping jaws for the purpose of illustrating their joint in a side view of the clamping jaws,

FIG. 5

a jaw of the gripper device after FIG. 3 and 4 in perspective, partially sectioned illustration and

FIG. 6

the gripper device after FIG. 3 , cut along the line VI-VI in a detail and on a different scale.

In FIG. 1 there is illustrated an Axminster weaving machine 1 used to make a pile fabric such as a carpet. It has a plurality of not illustrated warp beams, of which a plurality of warp threads 2, 3, 4 are introduced. With the warp threads 2, 3, 4 subjects are formed, in which a (usually double) weft thread 5 is registered ( FIG. 2 ). To shed serve heald shafts 6, 7, 8, the strands for guiding the warp threads 2, 3, 4 have.

This is between a position A, in which it uses the pile yarn 9 in the tissue, and a position B movable, in which it picks up the pile yarn from a yarn carrier 12. The thread carrier 12 may have a plurality of threads 13, 14 of different colors and may be controlled so as to pick up the desired thread (e.g., with a pattern-dependent selected color). A knife carrier 15 has one or more knives for cutting a piece of a desired length from the pile yarn, the end of which holds the gripper means 11.

The gripper device 11 is held on a bar 16, which carries a large number of other, equally trained gripper devices. These are in FIG. 1 arranged congruently one above the other perpendicular to the plane of the drawing. In addition to the bar 16, a control shaft 17 is provided for opening and closing the gripper device 11. The bar 16 and the control shaft 17 are pivotable together so that the gripper devices 11 are moved back and forth between the positions A and B.

To the Axminster weaving machine 1 also includes a stop bar with corresponding blades 18, as for example FIG. 2 can be seen.

The separately in FIG. 3 illustrated gripper device has two clamping jaws 19, 21. The to be connected to the Barre 16 jaws 19 is often referred to as a base. The pivotally mounted on the jaws 19 jaws 21 is often referred to as a lever. The jaws 19, 21 are flat sheet metal parts with a thickness of one or a few millimeters. They point perpendicular to the drawing plane in FIG. 3 a matching thickness. Their edges are substantially in the same planes, ie the jaws 19, 21 are arranged without lateral offset to each other. The jaw 19 is formed as an approximately right angle. At its end 16 associated with the bar 16, it is provided with a fastening profile 23 in the form of a T-cutout. At its opposite end 24 it runs at substantially constant thickness D (illustrated in FIG Fig. 6 ) wedge-shaped. On its side facing the clamping jaw 21, it can be provided with a gripper surface 25. The gripper surface 25 may be upset, soldered or welded. Preferably, it is profiled.

The jaws 21 is also formed angular. At its the control shaft 17 associated end, it is provided with a coupling profile 26 which may be formed, for example, as an approximately rectangular cutout. The control shaft 17 engages with a corresponding projection in the coupling profile 26 to move the respective end of the jaw 21 to the bar 16 or away. The other end 28 of the jaw 21 in turn runs out wedge-shaped and is provided with a profiled, upset, welded or otherwise formed gripper surface 29.

The ends 24, 28 of the jaws 19, 21 form a tapered beak 31st

For articulated mounting of the jaws 19, 21 to each other is a hinge 32. It defines a transverse to the jaws 19, 21 and thus in FIG. 3 fixed pivot axis 33 fixed to the plane of the drawing.

The structure of the joint 32 opens from the FIGS. 4 to 6 , Both jaws 19, 21 each have an annular flattened portion 34, 35 in the region of the joint 32. While at the section 34 a particular from the Figures 5 . 6 apparent short tubular extension 36 is formed, the portion 35 is provided with a bearing opening 37. The extension 36 preferably merges integrally into the material of the clamping jaw 19, ie it is connected without joints. Its outer peripheral surface may form a narrow cylindrical bearing surface 38. The extension 36 is preferably only about so long that its preferably flat, annular end face in a common plane with the planar, in Fig. 6 upper flat side 20 of the jaw 19 or below it. In any case, serving as a tubular rivet extension 36 does not protrude beyond the corresponding flat side 20 in the preferred embodiment. In the direction of the thickness D is the length or width of the bearing surface 38 preferably at least a fifth to a quarter of the total thickness D. The wall of the bearing opening 37 may then form a corresponding likewise cylindrical abutment surface 39. Both bearing surfaces 38, 39 are arranged parallel to the pivot axis 33 in the embodiment shown. But they can also be arranged at an angle (not shown) to the pivot axis 33.

In order to keep the jaws 19, 21 captive to each other, i. To secure the joint 32 in the axial direction, the extension 36 may be slightly compressed at its upper edge, or be deformed radially outwardly. The radially outwardly deformed edge region 41 thus forms an annular, the clamping jaws 19 at the edge of its bearing opening 37 cross and thus positively locking portion and in this sense a rivet. The rivet connection is therefore at the same time attachment and joint, with a precise radial bearing is achieved by the mating of the cylindrical bearing surface 38 and the abutment surface 39. For receiving the edge region 41, the bearing opening 37 may be countersunk cone-shaped.

The gripping device 11 described so far shows a significantly improved behavior compared to conventional gripper devices as a result of the more precise storage by the joint 32. Due to the reduced radial clearance and bearing surfaces 38, 39 with a high cylindrical support component precision is ensured not only in the delivery condition but also over long periods of use.

In a preferred embodiment of the gripper device 11, a radial bearing 42 is additionally or alternatively provided to the radial bearing by the extension 36, which is formed by a formed on one of the jaws 19, 21, preferably annular bearing rib 43 and an associated annular groove 44. The bearing rib 43 and the annular groove 44 are arranged concentrically to the pivot axis 33. The bearing rib 43 protrudes from a plane surface 45, which is formed on the portion 34. Correspondingly, the annular groove 44 is introduced into a plane surface 46 which, on the section 35 (FIG. FIG. 4 ) is trained. The bearing rib 43 may be provided with recesses or interruptions.

In this embodiment, the bearing rib 43 may be provided with a cylindrical bearing surface 47, 48 both on its inside and on its outside. Corresponding abutment surfaces 49, 51 may be formed by the cylindrical groove flanks of the annular groove 44. In another embodiment, the radial tolerancing of the bearing surfaces 47, 48 and the abutment surface 49, 51 is narrower and the existing clearance is smaller than the clearance between the extension 36 and the bearing opening 37. Thus, the radial bearing is completely independent of the deformation of the edge 41 of the bearing rib 43 and the annular groove 44 set.

In a further embodiment, the radial bearing 42 is used as a lubrication point. In this case, before assembly of both jaws 19, 21 of the space between the bearing surface 47, 48 and the abutment surface 49, 51 and between the groove bottom 53 and the end face 52 with lubricant in the form of bearing grease or the like provided. This allows a maintenance-free joint 32. In this embodiment, a gap is preferably present between the groove bottom 53 and the end face 52 even when the plane surface 46 rests on the plane surface 45. The remaining gap serves as a lubricant reservoir.

Additionally or alternatively, the bearing rib, the axial bearing of the two jaws 19, 21 take on each other. In this case, the flat end face 52 of the bearing rib 43 and the flat groove bottom 53 of the annular groove 44 are in contact with each other. On the other hand, a certain amount of play then remains between the plane surfaces 45, 46. This is accomplished by adjusting the height of the bearing rib 43, i. the distance of the end face 52 from the flat surface 45 is greater than the depth of the annular groove 44, which can be seen as a distance between the flat surface 46 and the groove bottom 53. With this configuration, good lubrication with low friction and low wear is achieved. Oil retention is possible between the flat surfaces 45, 46, while the stiction due to the small surface area of the end face 52 and the groove bottom 53 is low.

The gripper 11 according to the invention is characterized in that the storage, ie the connection point between its clamping jaws 19, 21 has a cylindrical supporting portion. This support component preferably makes up at least one fifth to one quarter of the total thickness D of the clamping jaw. This corresponds to half the height of a projection 36 which is integrally formed on one of the clamping jaws 19, 21 and serves to support the clamping jaws 19, 21 together. While one half of the height of the projection 36 is used for storage, the other half with a slope formed by the inclined edge 41. The inclination is up to 45 °. A separate rivet is not available. Rather, the jaws 19, 21 are connected together by embossing. Manufacturing tolerances and tolerances due to wear during operation do not affect in the radial direction due to the cylindrical supporting portion of the bearing. This has the advantage that the clamping action of individual grippers is almost identical.

LIST OF REFERENCE NUMBERS

1

Axminster loom

2, 3, 4

warp

5

weft

6, 7, 8

heald

9

pile threads

11

Gripper device

12

thread carrier

13, 14

threads

15

blade carrier

16

bar

17

control shaft

18

lamella

19, 21

jaws

20

flat side

22

The End

23

mounting profile

24

The End

25

gripper surface

26

coupling profile

27, 28

The End

29

gripper surface

31

beak

32

joint

33

swivel axis

34, 35

section

36

extension

37

bearing opening

38

storage area

39

Thrust face

41

edge

42

radial bearing

43

Bearing rib, extension

44

ring groove

45, 46

plane surface

47, 48

storage area

49, 51

Thrust face

52

face

53

groove bottom

A, B

positions

D

thickness

Claims (9)

1. Gripper device (11) for an Axminster weaving loom
   with a first and a second clamping jaw (19, 21), which respectively have a gripping surface (25, 29) for clamping a pile thread (9),
   with a joint (32), which pivots the two clamping jaws (19, 21) to one another and in so doing defines a pivot axis (33),
   characterised in that on one of the clamping jaws (19, 21) a bearing rib (43), which has an associated annular groove (44) configured in the respective other clamping jaw (21, 19), is arranged concentrically to an extension (36).
2. Gripper device according to claim 1, characterised in that a cylindrical bearing surface (47, 48) is configured on the bearing rib (43).
3. Gripper device according to claim 1, characterised in that the extension (36) is configured as a ring section connected in one piece to one of the clamping jaws (19, 21).
4. Gripper device according to claim 1, characterised in that the extension (36) is configured as a rivet.
5. Gripper device according to claim 1, characterised in that the bearing rib (43) is a ring-shaped raised section configured on an otherwise plane end face (45), which has an associated annular groove (44) configured in the respective other clamping jaw (21, 19).
6. Gripper device according to claim 5, characterised in that the bearing rib (43) and/or the annular groove (44) have one or more interruptions.
7. Gripper device according to claim 1, characterised in that the bearing rib (43) has a height exceeding the depth of the annular groove (44).
8. Gripper device according to claim 1, characterised in that the radial play of the bearing rib (43) in the annular groove (44) is less than the radial play of the extension (36) in the bearing opening (37).
9. Gripper device according to claim 1, characterised in that the radial play of the bearing rib (43) in the annular groove (44) is greater than the radial play of the extension (36) in the bearing opening (37).

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