Gripper and method for producing gripper

Abstract

The invention relates to a gripper for a rapier loom, the gripper (1) comprising a base portion (2) and a gripper chuck (3) wherein the base portion (2) comprises a bottom structure (20) having a first side (201) and an opposite second side (202), a top structure (23), a first side structure (21) connecting the top structure (23) to the bottom structure (20) at the first side (201) of the bottom structure (20), and a second side structure (22) connecting the second side (202) of the bottom structure (20) at the second side (202) of the bottom structure (20). And a second side structure (22) connecting the top structure (23) to the bottom structure (20) offset from a second side (202) of the bottom structure (20), where the gripper chuck (3) is arranged at the bottom structure (20) at a side of the second side structure (22) facing away from the first side structure (21), where the top structure (23) comprises a rectangular section (230), wherein a length of the rectangular section (230) in a longitudinal direction of the base portion (2) is greater than a width of the rectangular section (230) between the first side structure (21) and the second side structure (22), and wherein the second side structure (22) connects the rectangular section (230) of the top structure (23) to the bottom structure (20) at least at a rear end (31) of the rectangular section (230) and at a front end (32) of the rectangular section (230). The invention also relates to a weaving machine and a method for manufacturing the gripper.

Description

TECHNICAL FIELD

[0001] The present invention relates to a gripper for a gripper weaving machine, also known as a gripper loom. More specifically, the invention relates to a gripper having a base portion and a gripper head. The invention also relates to a loom and a method for manufacturing a gripper. BACKGROUND

[0002] It is known that a gripper weaving machine typically comprises two grippers for transporting a weft thread through a weaving shed, for example a so-called drawing gripper and a receiving gripper, wherein the drawing gripper is designed to guide the weft thread through a first half of the weaving shed and the receiving gripper is designed to guide the weft thread through a second half of the weaving shed after picking up the weft thread from the drawing gripper. Typically, a gripper equipped with a hook is used as a receiving gripper.

[0003] JP2000119935 shows a gripper comprising a base portion consisting of a lower wall, a vertical standing wall provided at one side of the lower wall, a side wall provided at the other side of the lower wall, an upper wall joined with the side wall and opposite to the lower wall, and a hanging wall suspended from the upper wall, wherein a joining piece is formed at the lowermost portion of the hanging wall, which is joined and fixed at the upper surface of the lower wall. SUMMARY

[0004] It is an object of the present invention to provide a light and strong gripper, in particular a drawing gripper, and a method for manufacturing such a gripper.

[0005] These objects are solved with a gripper and a method having the features of claims 1 and 15. Preferred embodiments are defined in the dependent claims.

[0006] According to a first aspect, there is provided a gripper, in particular a drawing gripper, for a gripper weaving machine, the gripper comprising a base portion and a gripper head, wherein the base portion comprises a bottom structure having a first side and an opposite second side, a top structure, a first side structure connecting the top structure to the bottom structure at the first side of the bottom structure, and a second side structure connecting the top structure to the bottom structure offset from the second side of the bottom structure, wherein the gripper head is arranged at the bottom structure at a side of the second side structure facing away from the first side structure, wherein the top structure comprises a rectangular section, wherein a length of the rectangular section in a longitudinal direction of the base portion is greater than a width between the first side structure and the second side structure, and wherein the second side structure connects the rectangular section of the top structure to the bottom structure at least at a rear end of the rectangular section and at a front end of the rectangular section.

[0007] In the context of the present application, the expression "structure" is used to describe a wall portion of the gripper, wherein the wall portion can be in the form of a grid structure, or in the form of a plate-like or large structure. The expression "grid structure" is defined as a frame consisting of ribs, also referred to as pillars or bar elements, which are arranged for forming the frame while leaving open spaces between the ribs. The grid structure in embodiments has a repeating pattern; in other embodiments, the grid structure does not have a repeating pattern. The base portion in embodiments is at least partially manufactured using 3D printing, wherein the structure is at least partially in the form of a grid structure, to avoid material build-up and to allow for a lightweight and robust structure.

[0008] In the context of the present application, the expressions "first" and "second" are not to be interpreted as limiting the order or numerical limitation, but instead are only used to distinguish or identify individual components in a group. "A" and "an" are used as indefinite articles and are not to be interpreted as "exactly one". Furthermore, terms such as "top", "bottom", "vertical", "horizontal", "upper", "lower", etc. are used to describe the conventional arrangement of the parts when using the gripper and are not to be interpreted as limiting terms.

[0009] At the base portion, a circumferentially closed cell, also referred to as a tubular cell, is formed, which closed cell comprises a bottom structure, a first side structure, a top structure and a second side structure, which closed cell strengthens the base portion and thus allows to prevent deformation of the base portion. The closed cell comprises a rectangular section of the top structure, which is connected to the bottom structure via the second side structure, in particular along the entire length thereof. In embodiments, the rectangular section extends beyond the area reached by the receiving gripper for picking up a weft thread from the pulling gripper towards the back end of the base portion. Thus, the closed or tubular cell is connected to the bottom structure over a longer distance at the second side structure to allow for improved stability.

[0010] According to the present application, the gripper chuck is arranged at a side of the second side structure facing away from the first side structure. In other words, the gripper chuck is arranged at the outside of the closed cell formed by the bottom structure, the first side structure, the top structure and the second side structure. The side of the second side structure facing away from the first side structure is also referred to as the outside of the second side structure. Arranging the gripper chuck at the outside of the second side structure allows for replacing the gripper chuck, e.g. a worn gripper chuck, and avoids dust accumulation on the gripper chuck.

[0011] In embodiments, the rectangular section of the top structure is a grid structure. The grid structure allows for a lightweight and robust construction of the rectangular section. The grid structure also allows for a better view on the receiving gripper inside the pulling gripper.

[0012] In embodiments, the second side structure is a grid structure comprising a first rib arrangement arranged at the front end of the rectangular section and a second rib arrangement arranged at the rear end of the rectangular section. In the context of the present application, the expression "rib arrangement" describes an arrangement comprising one or more ribs. The ribs of one rib arrangement in embodiments are arranged to converge at a common area at the top structure.

[0013] In embodiments, the second rib arrangement comprises rear ribs arranged oblique with respect to the normal direction of the base structure, wherein the upper end of the rear ribs is arranged in front of the lower end of the rear ribs. In an alternative or in an additional embodiment, the second rib arrangement in embodiments comprises straight ribs, wherein the straight ribs extend along the normal direction of the base structure. In an alternative or in an additional embodiment, the second rib arrangement in embodiments comprises C-shaped curved ribs, in particular C-shaped curved ribs facing away from the first side structure, wherein the upper end of the C-shaped curved ribs is arranged at least substantially above the lower end of the C-shaped curved ribs in the longitudinal direction of the base portion. In an alternative or in an additional embodiment, the second rib arrangement in embodiments comprises forwardly inclined ribs, wherein the forwardly inclined ribs are inclined in a direction opposite to the rear ribs. It turned out that such a second rib arrangement is advantageous to provide a lightweight base portion with high stiffness.

[0014] In embodiments, the grid structure of the second side structure comprises additional ribs arranged between the first rib arrangement and the second rib arrangement.

[0015] In other embodiments, an open space is provided between the first rib arrangement and the second rib arrangement. The inventors found that a sufficient stiffness of the base portion can be achieved when connecting the rectangular section to the base structure only via the first rib arrangement and the second rib arrangement. This allows to provide a larger open space between the first rib arrangement and the second rib arrangement. The receiving gripper entering the closed cell for picking up a weft thread from the traction gripper moves along a movement path extending in the longitudinal direction of the traction gripper. Due to forces acting on the gripper and / or the receiving gripper, the receiving gripper can be laterally diverted out of said movement path. Although the second side structure connecting the rectangular section to the base structure is longer, the large open space in the second side structure of the gripper also allows to avoid or at least reduce a contact of the traction gripper with the laterally diverted receiving gripper.

[0016] In embodiments, the top structure comprises a rear tapered section arranged at the rear end of the rectangular section, wherein the rear tapered section is directed towards the first side structure. In embodiments, the first side structure connects the rear tapered section and at least an adjoining portion of the rectangular section to the bottom structure. In embodiments, the first side structure connects about 10% to 70% of the rectangular section to the bottom structure, wherein the remaining portion of the rectangular section is not connected to the first side structure to allow the weft thread picked up by the gripper to enter between the top structure and the first side structure.

[0017] In embodiments, the base portion comprises an annular connecting portion arranged between the rear tapered section of the top structure and the bottom structure, wherein the annular connecting portion is adapted to connect the base portion to a guide rail arranged between the bottom structure and the annular connecting portion, and wherein the outer corner section of the rear tapered section is connected to the annular connecting portion via a rib, in particular via an inclined rib. In embodiments, the annular connecting portion is bolted to the bottom structure, wherein the guide rail is arranged between the bottom structure and the annular connecting portion. The rib, in particular the inclined rib, further improves the stability of the closed or tubular unit.

[0018] In an alternative, in embodiments, the outer corner section of the rear tapered section is connected to the bottom structure via a rib, in particular via an inclined rib.

[0019] In an alternative or additional alternative of the rear tapered section, in embodiments, the top structure comprises a front tapered section arranged at the front end of the rectangular section, wherein the front tapered section is directed towards the second side structure, and wherein the front tapered section is not connected to the bottom structure. As the front tapered section is not connected to the bottom structure, the weft thread picked up by the gripper can enter between the front tapered section and the bottom structure. In embodiments, the front tapered section is provided with a downwardly directed guiding portion for guiding the weft thread. In an alternative or in an additional alternative, the first side structure in embodiments has an entry recess for the weft thread at a section of the front tapered section.

[0020] In embodiments, the top structure comprises a shielding rib protruding from the top structure, which shielding rib extends along the rectangular section at a side of the rectangular section facing the first side structure. The shielding rib shields the weft thread from the warp threads when the gripper moves into the shed.

[0021] In embodiments, the weft thread picked up by the gripper extends between the gripper chuck and a slot provided opposite the gripper chuck between the first side structure and the top structure. In alternative or additional embodiments, in embodiments, an auxiliary gripper chuck is provided at the region of the first side structure. In embodiments, the auxiliary gripper chuck is attached to the inner side of the top structure in the region of the first side structure via a mounting assembly comprising a first part arranged at the top structure and a second part connected to the top structure, wherein a slit for receiving the auxiliary gripper chuck is formed between the first part and the second part. The mounting assembly allows for an easy mounting of the auxiliary gripper chuck to the inner side of the top structure, i.e. the side of the top structure facing the bottom structure, even in the case of a closed or tubular unit.

[0022] In embodiments, the gripper further comprises a guide plate provided below the bottom structure.

[0023] According to a second aspect, a weaving machine is provided, the weaving machine comprising a gripper, in particular a drawing gripper, having a base portion with a closed or tubular unit.

[0024] According to a third aspect, a method for manufacturing a gripper, in particular a drawing gripper, having a base portion with a closed or tubular unit is provided, wherein the base portion is formed as a one-piece part using 3D printing. When using 3D printing for manufacturing the base portion, a lightweight base portion with high stiffness can be provided due to the large closed or tubular unit comprising at least one lattice structure. BRIEF DESCRIPTION OF DRAWINGS

[0025] In the following, embodiments of the present application will be described in detail with reference to the accompanying drawings. In all drawings, like elements will be denoted by like reference signs.

[0026] Figure 1 An embodiment of a gripper comprising a base portion and a gripper chuck mounted on a rapier is shown in a first perspective view.

[0027] Figure 2 The base portion of the gripper of Figure 1 is shown in a first perspective view alone.

[0028] Figure 3 The base portion of the gripper of Figure 1 is shown in a second perspective view alone.

[0029] Figure 4 The base portion of the gripper of Figure 1 is shown in a third perspective view alone.

[0030] Figure 5 A gripper assembly comprisingFigure 1 The gripper and the guide rail for connecting the gripper to the sword shaft.

[0031] Figure 6 Shown in another perspective Figure 1 The gripper.

[0032] Figure 7 Another perspective view shows the mounting on the sword shaft. Figure 1 The gripper.

[0033] Figure 8 Previous view showed Figure 1 The base part of the clamp.

[0034] Figure 9 Shown in cross-sectional view Figure 1 Details of the gripper.

[0035] Figure 10 Another perspective view shows the mounting on the sword shaft. Figure 1 The gripper.

[0036] Figure 11 Shown in exploded view Figure 1 The gripper. Detailed Implementation

[0037] Figure 1 A clamp 1 for a rapier loom (not shown) is shown. The clamp 1 shown is a traction clamp designed to guide the weft yarn (not shown) through the first half of the weaving shed.

[0038] Figure 1 The clamp 1 shown includes a base portion 2, a clamp chuck 3, an auxiliary clamp chuck 4, and a guide plate 5.

[0039] Figures 2 to 4 Shown separately in several views Figure 1 The base portion 2 of the clamp 1.

[0040] The base portion 2 includes a bottom structure 20 having a first side 201 and an opposing second side 202; a first side structure 21; and a second side structure 22 (in... Figure 1 The base portion 2 is partially shielded by the gripper chuck 3, and includes a top structure 23. In the illustrated embodiment, the base portion 2 further includes a third side structure 24. The base portion 2 is manufactured as a single piece by 3D printing, wherein the bottom structure 20, the first side structure 21, the second side structure 22, the top structure 23, and the third side structure 24 are at least partially designed as a mesh structure, thereby forming a lightweight base portion 2 with sufficient rigidity.

[0041] The first side portion structure 21 connects the top portion structure 23 to the bottom portion structure 20 at a first side 201 of the bottom portion structure 20. The second side portion structure 22 connects the top portion structure 23 to the bottom portion structure 20 offset from a second side 202 of the bottom portion structure 20. The third side portion structure 24 is arranged at the second side 202 of the bottom portion structure 20 and protrudes upwardly from the bottom portion structure 20.

[0042] The gripper chuck 3 is arranged on the bottom portion structure 20 between the second side portion structure 22 and the third side portion structure 24 at an outer side of the second side portion structure 22.

[0043] In the shown embodiment, the top portion structure 23 comprises a rectangular section 230 arranged between the first side portion structure 21 and the second side portion structure 22, a rear tapering section 231 arranged at a rear end 31 of the rectangular section 230, wherein the rear tapering section 231 points towards the first side portion structure 21, and a front tapering section 232 arranged at a front end 32 of the rectangular section 230, wherein the front tapering section 232 points towards the second side portion structure 22.

[0044] The bottom portion structure 20, the first side portion structure 21, the top portion structure 23 and the second side portion structure 22 form a closed or tubular unit.

[0045] As Figure 3 As best seen in Fig. 2, the length of the rectangular section 230 in the longitudinal direction of the base portion 2 is greater than the width of the rectangular section 230 between the first side portion structure 21 and the second side portion structure 22. The rectangular section 230 extends beyond the area where the receiving gripper (not shown) enters the pulling gripper 1 for picking up a weft thread from the pulling gripper 1 towards the rear end 200 of the base portion 2. Thus, a large top portion structure 23 is provided which extends a long distance in the longitudinal direction.

[0046] The second side portion structure 22 connects the rectangular section 230 of the top portion structure 23 to the bottom portion structure 20 at the rear end 31 of the rectangular section 230 and at the front end 32 of the rectangular section 230. The second side portion structure 22 extends a long distance and also beyond the area where the receiving gripper (not shown) enters the pulling gripper 1 for picking up a weft thread from the pulling gripper 1. In other words, the top portion structure 23 is supported at one section via the second side portion structure 22 which is arranged beyond the area where the receiving gripper enters the pulling gripper 1 for picking up a weft thread from the pulling gripper 1. Thereby, the stability of the base portion 2 is improved.

[0047] In Figures 1 to 7 In particular Figure 2In the embodiment shown in Fig. 2, the second side structure 22 is a grid structure comprising a first rib arrangement 221 arranged at the front end 32 of the rectangular section 230 and a second rib arrangement 222 arranged at the rear end 31 of the rectangular section 230. An open space 220 is provided between the first rib arrangement 221 and the second rib arrangement 222. The open space 220 allows for a limited lateral movement (i.e. lateral with respect to the longitudinal direction) of a receiving gripper (not shown) entering the traction gripper 1 while avoiding or at least reducing the risk of the receiving gripper coming into contact with the second side structure 22 of the traction gripper 1.

[0048] In the embodiment shown in Fig. 2, the second side structure 22 is a grid structure comprising a first rib arrangement 221 arranged at the front end 32 of the rectangular section 230 and a second rib arrangement 222 arranged at the rear end 31 of the rectangular section 230. An open space 220 is provided between the first rib arrangement 221 and the second rib arrangement 222. The open space 220 allows for a limited lateral movement (i.e. lateral with respect to the longitudinal direction) of a receiving gripper (not shown) entering the traction gripper 1 while avoiding or at least reducing the risk of the receiving gripper coming into contact with the second side structure 22 of the traction gripper 1. Figures 1 to 7 In the embodiment shown in Fig. 2, the second side structure 22 is a grid structure comprising a first rib arrangement 221 arranged at the front end 32 of the rectangular section 230 and a second rib arrangement 222 arranged at the rear end 31 of the rectangular section 230. An open space 220 is provided between the first rib arrangement 221 and the second rib arrangement 222. The open space 220 allows for a limited lateral movement (i.e. lateral with respect to the longitudinal direction) of a receiving gripper (not shown) entering the traction gripper 1 while avoiding or at least reducing the risk of the receiving gripper coming into contact with the second side structure 22 of the traction gripper 1. Figure 2 In the embodiment shown in Fig. 2, the second side structure 22 is a grid structure comprising a first rib arrangement 221 arranged at the front end 32 of the rectangular section 230 and a second rib arrangement 222 arranged at the rear end 31 of the rectangular section 230. An open space 220 is provided between the first rib arrangement 221 and the second rib arrangement 222. The open space 220 allows for a limited lateral movement (i.e. lateral with respect to the longitudinal direction) of a receiving gripper (not shown) entering the traction gripper 1 while avoiding or at least reducing the risk of the receiving gripper coming into contact with the second side structure 22 of the traction gripper 1.

[0049] In the embodiment shown in Fig. 2, the second side structure 22 is a grid structure comprising a first rib arrangement 221 arranged at the front end 32 of the rectangular section 230 and a second rib arrangement 222 arranged at the rear end 31 of the rectangular section 230. An open space 220 is provided between the first rib arrangement 221 and the second rib arrangement 222. The open space 220 allows for a limited lateral movement (i.e. lateral with respect to the longitudinal direction) of a receiving gripper (not shown) entering the traction gripper 1 while avoiding or at least reducing the risk of the receiving gripper coming into contact with the second side structure 22 of the traction gripper 1. Figures 2 to 4 In the embodiment shown in Fig. 2, the second side structure 22 is a grid structure comprising a first rib arrangement 221 arranged at the front end 32 of the rectangular section 230 and a second rib arrangement 222 arranged at the rear end 31 of the rectangular section 230. An open space 220 is provided between the first rib arrangement 221 and the second rib arrangement 222. The open space 220 allows for a limited lateral movement (i.e. lateral with respect to the longitudinal direction) of a receiving gripper (not shown) entering the traction gripper 1 while avoiding or at least reducing the risk of the receiving gripper coming into contact with the second side structure 22 of the traction gripper 1.

[0050] In the embodiment shown in Fig. 2, the second side structure 22 is a grid structure comprising a first rib arrangement 221 arranged at the front end 32 of the rectangular section 230 and a second rib arrangement 222 arranged at the rear end 31 of the rectangular section 230. An open space 220 is provided between the first rib arrangement 221 and the second rib arrangement 222. The open space 220 allows for a limited lateral movement (i.e. lateral with respect to the longitudinal direction) of a receiving gripper (not shown) entering the traction gripper 1 while avoiding or at least reducing the risk of the receiving gripper coming into contact with the second side structure 22 of the traction gripper 1.

[0051] In order to reliably guide the weft yarn toward the gripper 3, in the illustrated embodiment, the front tapering section 232 is provided with downward-pointing guide portions 234, 235.

[0052] Furthermore, in order to reliably guide the weft yarn toward the auxiliary gripper chuck 4 and / or slot 26, the first side structure 21 has an entry recess 210 for the weft yarn in the section of the front tapering section 232. For example... Figure 7 As shown, when the auxiliary clamp 4 is attached to the base portion 2, the protruding end 40 of the auxiliary clamp 4 protrudes from the base portion 2 via the entry recess 210.

[0053] like Figures 3 to 6 As best seen in the illustrated embodiment, the base portion 2 includes an annular connecting portion 25 disposed between the rear tapering section 231 of the top structure 23 and the bottom structure 20. Figure 6 As best viewed from the center, the outer corner sections 238 and 239 of the tapered section 231 are connected to the annular connecting portion 25 via ribs 251 and 252 to increase the stability of the base portion 2. The ribs 251 and 252 are inclined in the longitudinal direction and transverse to the longitudinal direction of the clamp 1.

[0054] like Figure 7 and Figure 8 As shown, the annular connecting portion 25 is adapted to connect the base portion 2 to the guide rail 6, which is arranged between the bottom structure 20 and the annular connecting portion 25. In the illustrated embodiment, a sheet 7 is also arranged between the guide rail 6 and the annular connecting portion 25. Bolts 8 are inserted into the annular connecting portion 25 for connecting the base portion 2 and the guide rail 6. The guide rail 6 is secured to the rapier 10 via a plurality of bolts 9 (see...). Figure 7 and Figure 11 ), and connect the clamp 1 to the scissor 10. Bolts 8 and 9 can cooperate with nuts and washers.

[0055] In an alternative embodiment (not shown), the outer corner sections 238, 239 of the rear tapering section are connected to the bottom structure 20 via inclined ribs.

[0056] exist Figures 1 to 8 In the embodiment shown, an auxiliary gripper 4 is provided, wherein the auxiliary gripper 4 can be attached to the inside of the top structure 23 at a portion of the first side structure 21, i.e., the side of the top structure 23 facing the bottom structure 20.

[0057] In the illustrated embodiment, a mounting assembly 27 is provided to attach the auxiliary gripper 4 to the inside of the top structure 23.

[0058] Figure 9 A cross-sectional view shows the assembly including mounting component 27.Figures 1 to 8 Details of the clamp 1 are shown. The mounting assembly 27 includes a first portion 271 disposed at the top structure 23, particularly in the region of the rear tapered section 231; and a second portion 272 connected to the top structure 23 and projecting toward the second side structure 22. A slot 273 for receiving the auxiliary clamp chuck 4 is formed between the first portion 271 and the second portion 272. The first portion 271 has a through hole 274, and the second portion 272 has a threaded hole 275 aligned with the through hole 274. Figure 11 As best viewed, the auxiliary clamp chuck 4 is provided with a through slot 41 and an end slot 42. Therefore, after the auxiliary clamp chuck 4 is inserted into the slot 273, the end slot 42 can interact with the positioning portion 276 arranged at the slot 273, and the bolt 11 can be inserted through the through hole 274 of the first portion 271 and the through slot 41 of the auxiliary clamp chuck 4, and screwed into the threaded hole 275 to fix the auxiliary clamp chuck 4 to the base portion 2.

[0059] Figure 10 The clamp 1 as seen from the first side structure 21 is shown, illustrating the arrangement of the slot 26 and the shielding rib 237. The shielding rib 237 protrudes from the top structure 23 and extends along the rectangular section 230 on the side of the rectangular section 230 facing the first side structure 21.

[0060] Figure 11 Shown in exploded view Figure 1 The clamp 1 is provided to allow better visibility of its portion. In the illustrated embodiment, the clamp chuck 3 includes a base plate 50 and a rod 51 that are pushed against each other by a spring 52. The rod 51 is connected to a support portion 54 via a shaft 53, wherein the support portion 54 is secured to the clamp body 2 by bolts 55. The bolts 55 cooperate with threaded openings 57 provided in the clamp body 2. A distance element 56 is provided between the base plate 50 and the base portion 2. A guide plate 5 snaps onto the base portion 2. Additional bolts 58 are arranged between the base plate 50 and the support portion 54.

[0061] As described above, the guide rail 6 is fixed to the sword shaft 10 by a plurality of bolts 9, and the clamp 1 is connected to the sword shaft 10. Furthermore, in the illustrated embodiment, bolts 8 are inserted into the annular connecting portion 25 for connecting the base portion 2 and the guide rail 6.

[0062] In an alternative embodiment (not shown), the annular connection portion 25 is not provided compared to the illustrated embodiment.

[0063] In an alternative or in an additional solution, in another embodiment (not shown), the first rib arrangement 221 can comprise two ribs extending in the direction of the normal of the bottom structure 20, and / or the second rib arrangement 222 can comprise triangular ribs.

[0064] In yet another embodiment (not shown), no open space is provided between the first rib arrangement 221 and the second rib arrangement 222, and / or an additional rib is provided in place of the open space.

Claims

1. A gripper for a rapier weaving machine, the gripper (1) comprising a base portion (2) and a gripper head (3), wherein the base portion (2) comprises a bottom structure (20) having a first side (201) and an opposite second side (202), a top structure (23), a first side portion structure (21) connecting the top structure (23) to the bottom structure (20) at the first side (201) of the bottom structure (20), and a second side portion structure (22) connecting the top structure (23) to the bottom structure (20) offset from the second side (202) of the bottom structure (20), and wherein the gripper head (3) is arranged at the bottom structure (20) at a side of the second side portion structure (22) facing away from the first side portion structure (21), characterized in that, The top structure (23) comprises a rectangular section (230), wherein a length of the rectangular section (230) in a longitudinal direction of the base portion (2) is greater than a width of the rectangular section (230) between the first side structure (21) and the second side structure (22), and wherein the second side structure (22) connects the rectangular section (230) of the top structure (23) to the bottom structure (20) at least at a rear end (31) of the rectangular section (230) and at a front end (32) of the rectangular section (230).

2. The holder according to claim 1, characterized in that The rectangular section (230) of the top structure (23) is a grid structure.

3. Holder according to claim 1 or 2, characterized in that The second side structure (22) is a grid structure comprising a first rib arrangement (221) arranged at the front end (32) of the rectangular section (230) and a second rib arrangement (222) arranged at the rear end (31) of the rectangular section (230).

4. The holder of claim 3, wherein The second rib arrangement (222) comprises rear ribs (223) arranged oblique with respect to a normal direction of the bottom structure (20), wherein an upper end of the rear ribs (223) is arranged in front of a lower end of the rear ribs (223).

5. A gripper according to claim 3 or 4, characterised in that The second rib arrangement (222) comprises straight ribs, wherein the straight ribs extend along a normal direction of the bottom structure (20); and / or the second rib arrangement comprises rear ribs (223) arranged oblique with respect to a normal direction of the bottom structure (20), wherein an upper end of the rear ribs (223) is arranged in front of a lower end of the rear ribs (223); and / or the second rib arrangement (222) comprises C-shaped curved ribs (224), in particular C-shaped curved ribs (224) facing away from the first side structure (22), wherein an upper end of the C-shaped curved ribs (224) is arranged at least substantially above a lower end of the C-shaped curved ribs (224) in a longitudinal direction of the base portion (2); and / or the second rib arrangement (222) comprises forwardly inclined ribs (225), wherein the forwardly inclined ribs (225) are inclined in a direction opposite to the rear ribs (223).

6. A holder according to claim 3, 4 or 5, characterised in that An open space (220) is provided between the first rib arrangement (221) and the second rib arrangement (222).

7. The holder according to any one of claims 1 to 6, characterized in that The top structure (23) comprises a rear tapering section (231) arranged at the rear end (31) of the rectangular section (230), wherein the rear tapering section (231) is pointing towards the first side structure (21), and wherein in particular the first side structure (21) connects the rear tapering section (231) as well as at least an adjoining portion of the rectangular section (230) to the bottom structure (20).

8. The holder of claim 7, wherein The base portion (2) comprises an annular connecting portion (25) arranged between a rear tapering section (231) of the top structure (23) and the bottom structure (20), wherein the annular connecting portion (25) is adapted for connecting the base portion (2) to a rail (6) arranged between the bottom structure (20) and the annular connecting portion (25), and wherein outer corner sections (238, 239) of the rear tapering section (231) are connected to the annular connecting portion (25) via ribs (251, 252), in particular inclined ribs.

9. The holder according to any one of claims 1 to 8, characterized in that, The gripper is a pulling gripper designed to guide weft threads through a first half of a weaving shed.

10. The holder according to any one of claims 1 to 9, characterized in that The top structure (23) comprises a front tapering section (232) arranged at a front end (32) of the rectangular section (230), wherein the front tapering section (232) is pointing towards the second side structure (22), and wherein the front tapering section (232) is not connected to the bottom structure (20), and in particular wherein the front tapering section (232) is provided with downwardly pointing guide portions (234, 235) for guiding weft threads, and / or wherein the first side structure (21) has an entry recess (210) for weft threads at a section of the front tapering section (232).

11. The holder according to any one of claims 1 to 10, characterized in that The top structure (23) comprises a shielding rib (237) protruding from the top structure (23), the shielding rib (237) extending along the rectangular section (230) at a side of the rectangular section (230) facing the first side structure (21).

12. The holder according to any one of claims 1 to 11, characterized in that A supplementary gripper chuck (4) is provided, wherein in particular the supplementary gripper chuck (4) is attached to an inner side of the top structure (23) in a section of the first side structure (21) via a mounting assembly (27), the mounting assembly (27) comprising a first part (271) arranged at the top structure (23) and a second part (272) connected to the top structure (23), wherein a slit (273) for receiving the supplementary gripper chuck (4) is formed between the first part (271) and the second part (272).

13. The holder according to any one of claims 1 to 12, characterized in that A guide plate (5) is provided below the bottom structure (20).

14. Loom, characterized in that The weaving machine comprises a gripper (1) according to any one of claims 1 to 13.

15. Method for manufacturing a gripper according to any one of claims 1 to 13, wherein the base portion (2) is an integral part formed using 3D printing.

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