Gripper weaving machine with ribbed guide porton connected to rapier

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a gripper weaving machine comprising at least one gripper mounted by a guide portion to a rapier, further comprising guide units arranged in a row and insertable into an open shed and fitted with guides guiding the rapier and the guide portion.

2. Background of the Invention

A gripper weaving machine of the above type is known for example from the European patent document A1 0,576,854. The guide units are fitted with guide elements which are associated with the top and bottom sides of the rapier and to the upper sides and undersides of the guide portion that are flush with said top and bottom sides. At least one guide rib is provided at the guide portion and is associated with a transverse guide of the guide units. Accordingly transverse guidance takes place only in the region of the guide portion, the rapier per se being of uniform and substantially rectangular cross-section. Accordingly the rapier is designed to be comparatively flexible in the direction of is its flat sides while being relatively stiff transversely. This design is possible because the transverse guidance is provided by the guide portion.

Desirably the speed of operation is increased in gripper weaving machines of the this type, in particular the filling frequency. This filling frequency can be raised when the shed that just received the filling is already closing before the gripper(s) has (have) been fully withdrawn from it.

SUMMARY OF THE INVENTION

The objective of the invention is to design a gripper weaving machine so that shed closure before full gripper withdrawal will be as free as possible of malfunction.

This problem is solved in that the guide portion at its side facing away from the gripper is fitted with at least one slide rib running in the longitudinal direction of the guide portion that protects the warps against contact with the guide portion.

When closing the shed before the gripper has been fully withdrawn from it, the minimum of one slide rib prevents warps from coming into contact with the guide portion, thereby assuring in the first place that the warps will not damage the typically plastic guide portion, in particular its guidance surfaces and, on the other hand, avoiding damaging or tangling the warps by the wear-susceptible guidance surfaces of the guide portion.

To carry out the invention, at least one slide rib is provided at the guide portion and/or the gripper, as an extension of this gripper and extending in the direction of the rapier. The rib protects the warps against making contact with the guide portion. Typically the gripper is made of a metal having a comparatively low coefficient of friction relative to the warps. The gripper projects beyond the guide portion so that warps resting against it will not touch the guide portion. This effect is maintained over the entire length of the guide portion when the slide rib is present, and accordingly the danger of damaging the guide portion and/or the warps is substantially reduced in this region.

Further features and advantages of the invention will be made evident from the following description of the embodiments shown in the drawings and from the appended claims.

FIG. 1

is a schematic cross-section of a gripper weaving machine,

FIG. 2

shows a section along line II—II of

FIG. 1

on a larger scale,

FIG. 3

is a section similar to that of

FIG. 2

on a still larger scale, the shed already having partly closed while the gripper has not yet been fully withdrawn from it,

FIG. 4

is a schematic side view of the gripper with a guide portion and slide ribs,

FIG. 5

is a bottom view of the embodiment of

FIG. 4

,

FIG. 6

is a section similar to that of

Fig.3

of an embodiment with another guidance-part,

FIG. 7

is a bottom view (on a smaller scale) of the guide portion of

FIG. 5

, and of the adjoining rapier and gripper,

FIG. 8

is a section similar to

FIG. 3

of another embodiment,

FIG. 9

is a bottom view of the guide portion of FIG.

8

and the adjoining rapier with the gripper projecting beyond this rapier, and

FIGS. 10

,

11

are a sideview and a view from below of a guide portion showing the slide ribs extending into the front zone of the rapier.

The gripper weaving machine shown in

FIG. 1

comprises a feed gripper

1

and a receiving gripper

2

each inserted by a rapier

3

,

4

into a shed. From the weft feeding device, the feed gripper

1

carries a filling which it inserts into the shed and, at the center of the weaving machine, transfers the filling to the receiving gripper

2

which, upon its withdrawal, carries the filling to the opposite side of the shed.

The rapiers

3

,

4

are actuated by drives mounted in mirror-symmetrical manner in the region of the lateral machine frame components

5

. The rapiers

3

,

4

are driven by a drive wheel

7

and are kept in contact with the drive wheel

7

by guide shoes

8

. Typically the drive wheel

7

is a gear engaging perforations in the rapiers

3

,

4

by gear teeth.

The drives

6

for the rapiers

3

,

4

are synchronized by a drive

9

and drive a batten

10

supported in the lateral machine frame components

5

. The batten

10

is shown in greater detail in FIG.

2

and comprises a batten fitting

11

non-rotatably affixed by screws

12

on a batten shaft

13

. A reed

15

is affixed by fasteners

14

to the batten fitting

11

.

An intermediate fitting

16

is affixed by screws

17

to the batten fitting

11

, with guide units

19

, which are mounted in a row, being fastened by screws

18

to said intermediate fitting

16

. The guide units

19

, in a manner described below, form guides

20

for the rapiers

3

,

4

and a guide portion

21

which supports the gripper

1

or

2

and which in turn is connected to the rapier

3

or

4

. These components are discussed below only for the feed gripper

1

because the design is identical for the receiving gripper

2

.

Moreover the gripper weaving machine comprises means (not shown) to form sheds

22

with upperwarps

23

and lowerwarps

24

. The means forming the sheds

22

are synchronized with the batten drive

9

and thereby also with the drives

6

for the rapiers

3

,

4

. A filling is inserted by the feed gripper

1

and the receiving gripper

2

into the opened sheds

22

, and this filling then is beaten by the reed

15

against the cloth

25

through the pivoting motion of the batten

10

.

The guide units

19

pivot together with the batten

10

and when a filling is beaten against the cloth

25

they will move into the position shown in dashed lines. In the maximum pivoted position of the batten

10

away from the cloth

25

as shown in

FIG. 2

, the guide units

19

have entered the shed

22

between the lower warps

24

. In that position, the feed gripper

1

and the receiving gripper

2

are inserted into the open shed

22

. The closing procedure of the shed

22

already begins after the filling has been transferred from the feed gripper

1

to the receiving gripper

2

, the warps

23

,

24

moving toward each other as shown in dashed lines in FIG.

3

. During this closing procedure, the feed gripper

1

and the receiving gripper

2

have not yet moved completely out of the shed

22

. As a result the upper warps

23

rest against the feed gripper

1

and the receiving gripper

2

. The feed gripper

1

and the receiving gripper

2

are illustratively constructed in the manner of U.S. Pat. 4,860,800 and 4,708,174 and are made of a metal, in particular steel, their surfaces being smooth and polished so as to have comparatively low friction relative to the warps

23

. There is relatively little danger that the upper warps

23

will be damaged by the feed gripper

1

and the receiving gripper

2

, or that their position will be interfered with. To avoid damaging the lowerwarps

24

or tangling them by means of the guide portion

21

, or damaging the guide surfaces of the guide portion

21

by means of the warps

24

, a slide rib

26

is provided on the underside of the guide portion

21

opposite the feed gripper

1

or the receiving gripper

2

in the embodiment of

FIGS. 2 and 3

. This slide rib

26

is bonded into a recess of the guide portion

21

, or, during the manufacture of this guide portion

21

, it is shaped into it. The slide rib

26

projects sufficiently downward toward the lower warps

24

so that these warps will not come into contact with the guide portion

21

when the shed

22

is closing.

As regards the embodiment of

FIGS. 2 through 5

, on its side away from the reed

15

, the guide portion

21

is fitted with a downward-projecting guide rib

27

, running approximately over along the full length of the guide portion. A transverse guide

28

of the guide units

19

is associated with the guide rib

27

and consists of a U-shaped cross-section recess having mutually opposite side surfaces transversely guiding the side surfaces of the guide rib

27

. Moreover, the guide unit

19

comprises substantially mutually parallel guides

29

,

30

associated with the top and bottom sides of the rapiers

3

,

4

and hence with the top side and underside of the guide portion

21

which are flush with said top and lower sides. The bottom of the U-shaped recess

28

constituting the transverse guide for the slide rib

27

is deep enough that there will be significant spacing between this bottom and the rib

26

, as shown in

FIGS. 2 and 3

.

As shown by

FIGS. 4 and 5

, the feed and receiving grippers

1

and

2

resp. project forward beyond the guide portion

21

. The gripper extends as far as approximately the center of the guide portion

21

and terminates obliquely at the upper side of the guide portion

21

. A slide rib

31

is provided as an extension of the feed gripper

1

and projects from the upper side of the guide portion and somewhat overlaps the feed gripper

1

, extending somewhat beyond the end of the guide portion

21

and then terminating obliquely in the upper side of the rapier

3

, with the upper side of the band

3

being flush with the upper side of the guide portion

21

.

The guide rib

27

extends along the underside approximately over the entire length of the guide portion

21

. At both ends, this rib

27

terminates obliquely into the underside of the guide portion

21

. The slide rib

26

inserted in the guide rib

27

extends over the full length of the guide rib

27

and slants in such a manner at both ends that it is flush with the slant of the guide rib

27

.

As shown by

FIG. 5

, the widths of the rapier

3

and of the guide portion

21

are the same. The end of the guide portion

21

away from the gripper

1

, likewise the rapier, is fitted with a recess whereby the rapier

3

and the guide portion

21

overlap approximately over half the length of the guide portion in the area of this recess. The guide portion

21

and the rapier

3

are affixed to each other in this area.

As regards the embodiment of

FIGS. 6 and 7

, the guide portion

21

corresponds in its design to that of FIG.

3

and is fitted with a further slide rib

32

in the region of its side edge facing the reed

15

. This slide rib

32

only runs approximately over the front half of the guide portion

21

, merges by a slanted section into the underside of the quick portion, and permits reduction somewhat of the height of the slide rib

26

without the warps

24

coming into contact with the guide portion

21

when the shed is being closed. Moreover, the shed

22

may be closed even earlier before the feed gripper

1

is withdrawn from the shed

22

without the warps

24

touching the edge of the guide portion

21

facing the reed

15

.

As regards the embodiment of

FIGS. 8 and 9

, a guide portion

33

is used which also is fitted with a downward-projecting guide rib

34

on its side facing the reed

15

. Accordingly the transverse guidance of the this guide portion

33

is carried out between two guides

35

,

36

of the guide unit

19

which run perpendicularly to the guide

29

. The U-shaped recess

28

of the guide units

19

in this instance is somewhat wider than the guide rib

27

.

Both guide ribs

27

,

34

of the embodiment of

FIGS. 8 and 9

are fitted with slide ribs

26

,

37

which project downward equally. The slide rib

37

of the guide rib

34

however runs approximately only over the front half of the guide portion

33

.

As regards the embodiment of

FIGS. 10 and 11

, in a manner similar to the design of

FIGS. 8 and 9

, the guide portion includes guide ribs

27

,

34

on its underside. These guide ribs

27

are fitted with slide ribs

38

,

39

projecting beyond the guide portion

33

and extending as far as the beginning zone of the rapier

3

. They are fitted with oblique risers inserted into recesses of the rapier

3

. This feature ensures that warps will not snag at the transition between the guide portion

33

and the rapier but instead will be safely guided across this transition zone.

The guide portion

21

or

33

is made of a plastic which shall present the least possible sliding friction to the metallic guide units

19

. The slide ribs

26

,

32

,

37

,

38

,

39

and

31

are made of a wear-resistant material having minimal friction relative to the warps

24

. Preferably they will be metallic, in particular being made of steel and have a polished surface. The edges coming in contact with the warps

24

are rounded. The slide ribs

26

,

32

,

37

,

38

,

39

and

31

may be surface-treated to increase their wear resistance and/or to reduce the friction relative to the warps

24

. Illustratively they may be hardened or be coated. In another design the slide ribs

26

,

32

,

37

,

38

,

39

and

31

are non-metallic, for example, made of ceramics.