CN114790604A

CN114790604A - Yarn clamping device, yarn frame and drawing-in machine comprising such a yarn clamping device

Info

Publication number: CN114790604A
Application number: CN202210088778.7A
Authority: CN
Inventors: F·冈特利; I·弗罗梅尔特
Original assignee: Staeubli Sargans AG
Current assignee: Staeubli Sargans AG
Priority date: 2021-01-25
Filing date: 2022-01-25
Publication date: 2022-07-26
Also published as: EP4033021A1; CN114790605A; TW202235716A; EP4033020A1

Abstract

Yarn clamping device (20) comprising a clamping rail (22), a clamping lever (24), the clamping lever (24) being configured to be inserted into a clamping volume, the clamping lever (24) having a clamping rotational movement in a clamping direction (R2) relative to the clamping rail (22) from an insertion position to a clamping position. The thread clamping device further comprises at least one holding device (26) which comprises a barrier (90) which has a movement relative to the clamping lever from a retracted position into a blocking position during a clamping rotational movement of the clamping lever. The retracted position of the obstacle corresponds at least to the insertion position of the clamping lever, while the blocking position of the obstacle corresponds at least to an intermediate position with respect to the clamping rail (22), reached by the clamping lever in its clamping rotational movement, offset with respect to the insertion position. When the obstruction (90) is in its retracted position, it does not prevent rotational movement of the clamping lever between the insertion position and the clamping position within the clamping volume. When the obstacle is in its blocking position and when the clamping lever is in the intermediate position, the obstacle does not prevent a rotational movement of the clamping lever in the clamping space in a clamping direction (R2) towards its clamping position, but said obstacle prevents a rotational movement of the clamping lever in a direction (R3) within the clamping volume which is opposite to the clamping direction.

Description

Yarn clamping device, yarn frame and drawing-in machine comprising such a yarn clamping device

Technical Field

The invention relates to a yarn clamping device for clamping a yarn layer. The invention also relates to a yarn framework and a drawing-in machine comprising the yarn clamping device.

Background

In the weaving field, it is known to use yarn clamping devices for clamping different yarns of a warp layer, in particular during the warp preparation process. This process requires clamping the yarns of the yarn layer, for example, to bind two warp yarn layers together or to thread the warp yarns of the yarn layer through the bundles of the loom.

In this cono mutext, US-A-5381594 discloses A machine for automatically passing warp yarns, in which two pairs of yarn clamping devices are mounted on A single yarn frame which is longitudinally movable relative to the passing unit. A combination of relative adjustment between the two lower clamping rails in the longitudinal direction and in the direction of yarn extension is possible. A first embodiment of the gripping device comprises a comb introduced in a gripping housing defined between a fixed wall and a movable wall, the movement of which may cause jamming of the comb with the gripping track and jamming of some of the yarn between the comb and the gripping track. Therefore, even if it is satisfactory on a global scale, the implementation of such a drawing-in machine is difficult and expensive. Another embodiment of the clamping device comprises an elastic tube driven by a rotary clamping bar inserted into the clamping track of the yarn clamping device in order to block the yarn in the track. In the inserted position of the elastic tube, the yarn is between the tube and the clamping track, the tube having been deformed against the clamping track, which exerts a first clamping action on the yarn which is not easily regularly distributed or tensioned in this position. Furthermore, unless they are in the clamped position, the tubes and rods may be ejected from the clamping track under high tension in the yarn. In this case, the yarn clamping process should start again from the beginning.

EP- ｃA-2662481, on the other hand, discloses ｃA yarn frame with two spaced-apart clamping rails, each equipped with two rubber profiles and adapted to receive ｃA clamping bar. During the tensioning of the yarn layer, the yarn is first clamped in one of the clamping rails and then tensioned before the steering rod is introduced into the other clamping rail. This approach may result in relaxation of the yarn tension and/or an irregular tension distribution across the width of the yarn layer. Furthermore, the rods introduced into the clamping tracks can be ejected from these guides by the reaction forces exerted by the yarn, which can also lead to an irregular yarn distribution.

Disclosure of Invention

The object of the present invention is to solve these problems by providing an optimized yarn clamping device that allows to clamp the yarn efficiently during yarn clamping without the risk of ejecting the clamping bar.

In this respect, the invention relates to a yarn clamping device for clamping a yarn layer, comprising

A clamping track defining a clamping volume extending along a longitudinal axis,

a clamping rod configured to be inserted into the clamping volume through the insertion/extraction opening of the clamping rail and in a direction transverse to the longitudinal axis, a longitudinal portion of the clamping rod accommodated in the clamping volume having a non-circular cross-section, the clamping rod having a clamping rotational movement relative to the clamping rail in a clamping direction within a clamping space and about an axis of rotation parallel to the longitudinal axis of the clamping rail,

starting from an insertion position in which the rod can pass through the insertion/extraction opening and a first external dimension of the clamping rod cross section parallel to the width of the insertion/extraction opening is smaller than this width,

to a clamping position, in which the clamping rod clamps the yarn located in the clamping volume against an inner surface located inside the clamping track.

According to a further advantageous aspect of the invention, the yarn clamping device of the invention may comprise one or more of the following features in any technically compatible configuration:

-when the clamping bar is in the clamping position, the inner surface of the clamping rail partially defines a clamping volume at the level of the insertion/extraction opening, forming a holding zone cooperating with the clamping bar in the transverse direction, the yarn being in the middle thereof for blocking the clamping bar within the clamping volume.

The holding zones extend on both sides of the main plane.

The holding region of the clamping rail is formed by at least one part of the inner surface, which is centered on the axis of rotation, and the cylindrical portion cooperates in a form-fitting manner with the clamping lever in the clamping position of the clamping lever.

The inner surface of the rubber profile faces the insertion/extraction opening with an inclination angle with respect to the main plane of between 10 ° and 30 °, preferably approximately equal to 16 ° or 20 °.

The clamping bar partially protrudes out of the insertion/removal opening and out of the clamping rail when the clamping bar is in the clamping position.

When the clamping lever reaches and is offset with respect to the insertion position in its clamping movement in the clamping direction, in an intermediate position with respect to the clamping rail,

the non-circular cross-section of the clamping bar comprises at least a circular surface and a flat surface, wherein in the intermediate position the flat surface faces the inner surface of the rubber profile, wherein in the clamping position the flat surface faces the bottom of the clamping volume in a transverse direction in the opposite direction of the insertion/extraction opening, and wherein the inner surface of the clamping track partly defining the clamping volume cooperates with the circular surface for guiding a rotational movement of the clamping bar in the clamping volume between the intermediate position and the clamping position.

According to the invention, since the inner surface of the rubber profile through which the clamping bar passes is located only on one side of the main plane, the clamping bar in the clamping position engages only with the clamping rail on the other side of the main plane. The clamping position of the clamping bar within the clamping volume is thus better controlled. Since the clamping lever reaches the clamping position by rotation within the clamping volume, whereas the engagement with the rubber profile takes place only on one side of the main plane, a more regular tension distribution of the yarn within the yarn layer is obtained.

according to the invention, the yarn clamping device further comprises at least one holding device, which comprises an obstacle. The obstacle is configured to have a movement relative to the clamping lever during the clamping rotational movement of the clamping lever from a retracted position to a blocking position, the retracted position of the obstacle corresponding at least to the insertion position of the clamping lever, and the blocking position of the obstacle corresponding at least to an intermediate position relative to the clamping rail, which is reached by the clamping lever in its clamping rotational movement, offset relative to the insertion position, and furthermore, when the obstacle is in its retracted position, the obstacle does not prevent the rotational movement of the clamping lever within the clamping volume between the insertion position and the clamping position. When the obstacle is in its blocking position and the clamping lever is in the intermediate position, the obstacle

The clamping rod is not prevented from a rotational movement in the clamping direction in the clamping volume to its clamping position, but rather is prevented from a rotational movement in the clamping volume to its clamping position

Preventing rotational movement of the clamping bar within the clamping volume in a direction opposite to the clamping direction.

As a result of the fact that the inner surface of the rubber profile through which the clamping bar passes is located only on one side of the main plane, the clamping bar in the clamping position engages only with the clamping rail on the other side of the main plane, according to the invention. The clamping position of the clamping bar within the clamping volume is thus better controlled. Since the clamping lever reaches the clamping position by rotation within the clamping volume, whereas the engagement with the rubber profile takes place only on one side of the main plane, a more regular tension distribution of the yarn within the yarn layer is obtained. Any risk of ejection.

In a further advantageous aspect of the invention, the yarn clamping device of the invention may incorporate one or more of the following features in any technically compatible configuration:

-said retaining means further comprise a resilient member urging said obstacle towards its blocking position.

-said obstacle is housed at least partially in a housing of said yarn clamping device and is slidably movable between said retracted position and said blocking position along a direction transverse to said axis of rotation and a transverse direction.

The obstacle can be moved from its blocking position to its retracted position for all positions relative to the clamping rail reached by the clamping bar during the rotational movement in the clamping direction between the intermediate position and the clamping position.

In the insertion position and for all positions reached by the clamping lever during its rotational movement between the insertion position and an intermediate position in the clamping direction, the obstacle is held in the retracted position by the clamping lever or a part of the yarn clamping device, which part is rotationally connected to the clamping lever about the axis of rotation.

-a part of the clamping lever or the yarn clamping device, which is rotationally connected with the clamping lever about the axis of rotation, is configured to move the obstacle from its blocking position into the direction of its retracted position when the clamping lever is rotated from its clamping position into its insertion position within the clamping volume.

The yarn clamping device comprises two holding devices, one at each longitudinal end of the clamping rail, each holding device comprising a body accommodating the obstacle, each body being fixed with the clamping rail, and wherein the clamping bar comprises at least

-a first central longitudinal portion housed in the clamping shell for selectively clamping the yarn on an inner surface located inside the clamping track, and

-two second longitudinal portions, each of said second longitudinal portions being located on a longitudinal side of said first central longitudinal portion, housed in the body of the retaining device and adapted to cooperate with an obstacle.

The holding device further comprises a holding member which is rotationally connected with the clamping lever about the axis of rotation between an insertion position and an intermediate position, however, in the insertion position the holding member does not prevent movement of the clamping lever through the insertion/extraction opening, and in the intermediate position of the clamping lever the holding member abuts against the obstacle in a circumferential direction around the axis of rotation to prevent rotational movement of the clamping lever in a direction opposite to the clamping direction within the clamping volume.

-the holding member has an outer cylindrical surface centred on the axis of rotation and a recess configured to receive the clamping rod when the clamping rod is received within the clamping volume and defined by at least one branch having a plane parallel to the axis of rotation, while an obstacle is adapted to cooperate with the outer cylindrical surface of the holding member in the retracted position, wherein an end of the branch is configured to abut the obstacle in the blocking position in the circumferential direction, and wherein the plane of the clamping rod is in contact with the plane of the recess.

-in the blocking position of the obstacle, at the longitudinal height of the retaining member, the retaining member limits the width of the passage opening for the clamping bar from the notch to a dimension strictly smaller than the clamping bar's dimension parallel to the width of the passage opening.

-in an intermediate position of the clamping lever, a surface of the clamping lever abuts against the obstacle in a circumferential direction around the axis of rotation to prevent rotational movement of the clamping lever within the clamping volume in a direction opposite to the clamping direction.

The arrangement of the yarn clamping device is as described above, and

with respect to a main plane of the clamping volume which contains the axis of rotation and passes through the insertion/removal opening in the middle of the opening, one side of the clamping volume is defined by the clamping rail, wherein the other side of the clamping volume is delimited by the inner surface of the rubber profile accommodated in the clamping rail,

when the clamping bar is in the intermediate position, the clamping bar has a clearance with respect to the inner surface of the rubber profile, and

-when the clamping bar is in the clamping position, the clamping bar penetrates the inner surfaces of the rubber profile, the yarns being between the inner surfaces.

According to a second aspect, the invention relates to a yarn framework comprising at least two yarn clamping devices spaced apart in the direction of yarn extension, at least one of these yarn clamping devices being as described above.

Advantageously, the yarn framework is configured for clamping yarns of two yarn layers, wherein the yarn framework comprises

-a first pair of yarn gripping means spaced apart in the direction of yarn extension within the first layer for gripping the yarn of the first layer.

-a second pair of yarn clamping means spaced apart in the direction of yarn extension in the second layer for clamping the yarn of the second layer

Wherein

The yarn clamping device of the invention belongs to a pair of yarn clamping devices and is supported on a longitudinal beam of the yarn framework and is translatable with respect to the yarn clamping device of the other pair of yarn clamping devices along the longitudinal axis of its clamping volume, and/or

The yarn clamping devices of the invention belong to a pair of yarn clamping devices and in their clamping configuration the yarn of the first layer is interposed between a longitudinal beam of the yarn framework and a yarn clamping device of a second pair of yarn clamping devices, said second pair of yarn clamping devices being at least partially detachably mounted on the yarn framework.

In another advantageous aspect of the invention, the yarn clamping devices are as defined above, and the inner surface of the rubber profile is located on the same side of the main plane within the clamping volume as the other yarn clamping device of the same pair of yarn clamping devices.

Still advantageously, the inner surface of the rubber profile of the yarn clamping device according to the invention is located within the clamping volume on the same side of the main plane of the clamping volume as the other yarn clamping device of the same pair of yarn clamping devices.

In a third aspect, the invention relates to a drawing-in machine for drawing-in warp yarns through a woven tape, comprising at least one yarn framework as described above.

Advantageously, when the clamping lever is in the clamping position, the clamping lever projects partly through the insertion/removal opening and out of the clamping rail, the drawing-in unit is movable relative to the yarn frame along the longitudinal axis of the clamping rail, and at least one roller fixed longitudinally to the drawing-in unit is in contact with the clamping lever projecting from the clamping rail for guiding a relative movement between the drawing-in unit and the yarn frame along the longitudinal axis of the clamping rail.

Drawings

The invention will be better understood on the basis of the following description, given as a non-limiting example and made with reference to the following drawings:

figure 1 is a perspective view of a drawing-in machine according to the invention;

figure 2 is an enlarged partially exploded perspective view of a yarn framework according to the invention belonging to the drawing-in machine of figure 1;

figure 3 is a front view of the clamping device of the yarn framework of figure 2, which clamping device is in accordance with the present invention;

figure 4 is a cross-sectional view along the line iv-iv in figure 3, showing three positions of the clamping bar relative to the clamping rail at the level of the clamping volume;

figure 5 is a cross-sectional view along the line v-v in figure 3, showing the same three positions of the clamping bar at the level of the retaining means;

figure 6 is an exploded perspective view of the holding device of figure 5;

figure 7 is a cross-sectional view along the plane VII in figure 2;

FIG. 8 is an enlarged view of block VIII of FIG. 7;

fig. 9 is a perspective view comparable to block IX in fig. 2, with a single yarn layer and one yarn clamping device detached from the yarn framework portion;

figure 10 is an enlarged view of the box X in figure 9;

figure 11 is a view comparable to figure 5 of a clamping device according to a second embodiment of the invention;

figure 12 is a view similar to figure 5 of a clamping device according to a third embodiment of the invention; and

figure 13 is a cross-sectional view of a clamping device according to a fourth embodiment of the invention, compared with figure 4;

figure 14 is a partially exploded perspective view of the fourth embodiment compared to figure 2;

figure 15 is a cross-sectional view of the fourth embodiment compared to figure 7;

figure 16 is a cross-sectional view of a clamping device according to a fifth embodiment of the invention, compared with figure 4;

figure 17 is a cross-sectional view, equivalent to the lower part of figure 4, of a clamping device according to a sixth embodiment of the invention;

figure 18 is a cross-sectional view, equivalent to the lower part of figure 4, of a clamping device according to a seventh embodiment of the invention; and

fig. 19 is a partial perspective view of a binding device according to the invention, incorporating yarn clamping devices and a yarn frame.

Detailed Description

The drawing-in machine 2 shown in fig. 1 comprises a movable trolley 6 and a fixed structure 4 supporting a drawing-in unit 8, which drawing-in unit 8 may be of any known type and is represented by its external shape.

The warp threader 2 is designed to hold the warp yarns of the first layer L1 and the second layer L2 in position for the warp threading unit 8 to insert the warp yarns of these layers into a not shown portion of the bundle of the weaving machine. Some of which are mounted on support members 10 carried by the cart 6. Harnesses are known per se and may comprise heddles, reeds and sometimes also wires.

The two layers L1 and L2 are drawn from one or two warp beams, not shown, and are held by a yarn tensioning frame 12 (also referred to as a "draw-through frame"), said yarn tensioning frame 12 comprising three columns 14, some cross beams 15 and two beams 16, together forming the main structure of the frame 12.

The yarn frame 12 is mounted on the fixed structure 4 and can be tilted with respect to the main structure about an axis parallel to the longitudinal direction of the beam 16.

Each beam 16 carries two yarn clamping devices 20 arranged in pairs, which two yarn clamping devices 20 are provided for holding the yarns of the yarn layer L1 and the yarns of the yarn layer L2, respectively, with respect to the yarn frame 12. More precisely, the first yarn clamping device 20 of each pair is mounted on the upper beam 16A, while the second yarn clamping device of the same pair is mounted on the lower beam 16B. The yarn frame 12 thus comprises a total of four yarn clamping devices 20.

As can be taken from fig. 7 and 8, the beam 16 is hollow, with an overall rectangular cross section. Advantageously, the beams 16 have the same geometry. They may be cut to the same metal profile.

On each beam 16, two clamping devices 20 are positioned adjacent to each other, more precisely one above the other in the configuration of fig. 2, 7 and 8, wherein the yarn frame 12 extends substantially in a vertical plane. The two yarn clamping devices 20 of each pair are spaced apart in the direction of yarn extension within yarn layers L1 and L2, which in fig. 2, 7 and 8 are perpendicular to yarn layers L1 and L2.

The first pair of clamps 20 is formed by a lower yarn clamp 20a1 mounted on the upper beam 16A and an upper yarn clamp 20B1 mounted on the lower beam 16B. The first pair of yarn gripping devices 20 is used to grip the first layer L1. The first pair of yarn clamping devices 20 is formed by yarn clamping devices 20a1 and 20B1, which are mounted on the side of each beam 16 facing the other beam, respectively.

The second pair of yarn clamping devices 20 is formed by an upper yarn clamping device 20a2 mounted on the upper beam 16A and a lower yarn clamping device 20B2 mounted on the lower beam 16B. The second pair of yarn gripping devices is used to grip the second layer of warp yarns L2. The second pair of yarn clamping devices is formed by clamping devices 20a2 and 20B2 mounted on each beam 16, respectively, on the side of the beam opposite the other beam.

In the above, the reference numerals 20a1, 20a2, 20B1 and 20B2 are used to identify four yarn clamping devices. However, in the present embodiment, all four yarn clamping devices are identical unless otherwise specified, and the description of the common yarn clamping device, which is designated with reference numeral 20, applies to all yarn clamping devices.

Each yarn clamping device 20 comprises a clamping rail 22, a clamping bar 24 and two holding devices 26, each assembled by screws 28 at one respective longitudinal end of the clamping rail 22.

The clamping rail 22 is made of an aluminum profile having a constant cross section along the longitudinal axis X22 of the clamping rail. This cross-section is visible in fig. 4 and is generally C-shaped.

The clamping rail 22 has an inner cylindrical surface 31 with a circular cross-section centered on the longitudinal axis x22 with a diameter D31. The inner cylindrical surface 31 partially defines a clamping volume V22 within the clamping rail 22. The clamping volume opens on the front surface 23 of the clamping rail 22 through an opening O22, at the level of the two

portions

30a and 30b of the inner cylindrical surface 30, also centred on the axis X22, but with a diameter D30 smaller than the diameter D31.

The clamping rail 22 comprises a longitudinal recess 32 which forms a receiving housing for a rubber profile 34, which has an overall rectangular cross section and a side plane 36 facing the clamping volume v 22.

The flat surface 36 forms an inner surface of the clamping volume V22 within the clamping rail 22.

In an embodiment not shown, the surface 36 is not planar.

Y22 defines a lateral axis of the clamping rail 22 that is perpendicular to the axis X22 and passes through the opening O22 in the middle of the opening. The axes X22 and Y22 are tangential. Z22 defines a height or thickness axis of the clamping rail 22 that is perpendicular to axes X22 and Y22. The axes Y22 and Z22 are parallel to the plane of fig. 4 and are respectively perpendicular, parallel to the front surface 23.

The portion 30a and the portion 30b rotate along the transverse axis y22 at least partially toward the bottom of the clamping volume V22 at opposite ends of the opening O22. The front surfaces 23 of all clamping rails 22 of the yarn frame 12 extend substantially in the same plane, which is vertical in the drawing-in configuration. The inner surface 36 of the rubber profile 34, facing the opening O22, has an inclination angle α of between 10 ° and 30 °, preferably equal to about 20 °, with respect to a main plane P22 of the rail 22, said main plane P22 containing the axes X22 and Y22. The main plane P22 passes through the opening O22 in the middle of the opening. The inner cylindrical surface 30 extends on both sides of the main plane P22.

The

surfaces

31 and 36 are substantially flush with respect to the rubber profile 34 opposite the opening O22. Which together with the

portions

30a and 30b of the surface 30 define a clamping volume V22.

The clamping bar 24 is made of metal, such as aluminum or steel, and extends along a longitudinal axis X24, which longitudinal axis X24 is parallel to the axis X22 at least in the mounted configuration of the clamping bar 24 within the clamping volume v 22.

A single longitudinal recess 32 is provided in the clamping rail 22, so that a single rubber profile 34 or a single rubber profile line mounted in succession along the axis X22 is located beside the clamping volume v 22.

As shown in fig. 7, the rubber profiles 34 of the yarn clamping devices 20a1 or 20a2 mounted on the upper beam 16A are located in the respective clamping track 22, downwards with respect to its clamping volume V22, i.e. on one side of said clamping track, said clamping track facing along the axis Z22 towards the clamping track of the other yarn clamping device 20B1 or 20B2 belonging to the same pair of yarn clamping devices 20. In fig. 7, the rubber profiles 34 of the two upper yarn clamping devices 20a1 and 20a2 are located below their clamping volume V22, while the rubber profiles 34 of the two lower yarn clamping devices 20B1 and 20B2 are located above their respective clamping volume V22. In other words, in each yarn clamping device 20, the inner surface 36 of the rubber profile 34 is located, with respect to the main plane P22, on a single side of the clamping volume V22, which is directed along the axis z22 towards the other clamping device 20 of the same pair of clamping devices.

One or more spacers 38 may be received within the longitudinal recess 32 of each clamping rail 22 to adjust the protruding position of the inner surface 36 within the clamping volume v 22.

The clamping bar 24 extends along a longitudinal axis X24, which longitudinal axis X24 is parallel to the axis X22 at least in the mounted configuration of the clamping bar 24 within the clamping volume V22.

As shown in fig. 3 and 10, the clamping bar 24 comprises a central portion 42 configured to be housed within a clamping volume V22, and two end portions 44 and two intermediate portions 46 having a substantially square cross-section. Each intermediate portion 46 is along the axis X24 and is located between the central portion 42 and one of the end portions 44, i.e. on a longitudinal side of the central portion 42.

The cross-section of the clamping bar 24 along its central portion 42 is visible in fig. 4, while its cross-section along an intermediate portion 46 is visible in fig. 5.

At the level of its central portion 42, as can be seen in particular at the top of fig. 4, the clamping bar 24 is cylindrical, with a truncated-circular cross section defined on a portion of the periphery of the clamping bar 24. The circular surface 48, centered on the axis X24, has a diameter D1 and has a flat surface 50 on its remainder. The outer dimension D2, measured perpendicular to the axis X24 between the flat surface 50 and the most distal portion of the circular surface 48, is strictly smaller than the diameter D1. Thus, the clamping bar 24 has a non-circular profile in cross section in a plane perpendicular to the axis X24. P24 denotes the main plane of the lever 24, which includes its longitudinal axis X24 and is parallel to the flat surface 50. The maximum outer dimension of the non-circular profile of the stem 24 is parallel to the extension of the main plane P24 and is equal to the diameter D1. The diameter D1 is greater than the maximum outer dimension of the rod perpendicular to the main plane P24, i.e., the distance D2. The diameter D1 is substantially equal to the diameter D30, for example equal to 36 mm.

The square cross-section of the end 44 of the clamping bar 24 is adapted to cooperate with a tool (e.g. a wrench), not shown, in order to exert a torque on the clamping bar 24 about the axis X24.

At the level of one intermediate portion 46, as can be seen in particular at the top of fig. 5, the clamping bar 24 comprises two planar and

parallel surfaces

52 and 54 and two

surfaces

56 and 58, which are in the form of cylindrical portions having a circular base centered on the longitudinal axis. d2' represents the distance between

surfaces

52 and 54, measured perpendicular to these surfaces. Preferably, the distance d2' is slightly less than dimension d 2. D1' represents the diameter of

surfaces

56 and 58. Preferably, the diameter D1' is slightly smaller than the diameter D1.

Along axis X24, plane 52 of intermediate portion 46 extends flat surface 50 of central portion 42 toward the adjacent end portion 44, while plane 54 extends one of the planes of end portion 44 toward central portion 42.

Each retaining device 26 includes a body 60 secured together by a body portion 62, a support plate 64, and a cover 66. The

parts

62 and 66 are provided with holes 68 for the passage of the screws 28. The body portion 62 is also provided with threaded holes 70 for receiving screws 72 that pass through holes 74 of the cover 66 and secure the cover 66 and body portion 62 together.

The holding device 26 serves to limit the rotational movement of the clamping lever 24 within the clamping volume v 22.

The body portion 62 defines a housing H26 for receiving the C-shaped retaining member 76. More specifically, the body portion 62 has an inner cylindrical surface 80 with a circular cross-section centered on the central axis X60 of the body 60. The body 62 also has an end wall 82 which axially defines a housing H26 on one side, while the cover 66 defines the housing along axis X60 on the other side.

The end wall 82 and the cover 66 are provided with

central apertures

84 and 85, respectively, for the passage of the clamping bar 24. The two

central holes

84 and 85 have the same geometry.

The body 62 is also provided with a through hole 86, the through hole 86 extending from the housing H26 to an outer surface 88 of the body 62. The through hole 86 constitutes a housing for the shuttle 90, which shuttle 90 is resiliently biased by a spring 92 towards the housing H26, so that a rounded end 94 of the shuttle 90 opposite the spring 92 can protrude within the housing H26. A projection 93 is provided on the support plate 64 for centering the spring 92. Thus, the support plate 64 cooperates with the main body portion 62 to support the shuttle 90 within the through hole 86.

Y60 represents a transverse axis of the body 60, which is perpendicular to the axis X60 and passes through the opening O26.

In the mounted configuration of the retaining device 26 on the clamping track 22, the movement of the shuttle 90 takes place along a longitudinal axis a90 of the shuttle, which longitudinal axis a90 is parallel to the axis Z22, i.e. transverse to the longitudinal axis X60 and to the axis Y60. Movement of the shuttle 90 toward the housing H26 is limited by a shoulder formed by an annular collar 96 of the shuttle 90 which abuts an internal shoulder 98 formed in the through bore 86, as can be seen by a comparison of the two upper portions of fig. 5. The movement of the shuttle 90 out of the housing H26 is limited by the support plate 64, the support plate 64 being fixed to the main body portion 62 by means of two screws 99, said two screws 99 passing through two holes 100 provided in the support plate 64 and being screwed into two threaded blind holes 101 provided in the main body portion 62.

The shuttle 90 is provided with a through hole 102 transverse to its longitudinal axis a 90. The through hole 102 is sized to receive the ends of two transverse pins 104 that are received in

oblong slots

106 and 108 in the body portion 62 and the cover 66, respectively.

In fact, the transverse pin, visible on the left side of fig. 6, passes through the slot 108 and the first portion of the slot 106, so as to engage into the through hole 102, while still projecting outside the cover 66. On the other hand, the transverse pin 104, visible on the right side of fig. 6, passes through an invisible portion of the slot 106, which connects the through hole 86 to the surface of the main portion 62 perpendicular to the axis X60 and which is not visible on fig. 6. The transverse pin 104 also projects from the body portion 62. With this arrangement, the transverse pin 104 allows the shuttle 90 to be moved within the through hole 86, if necessary, against the elastic action of the spring 92.

The retaining member 76 has an outer cylindrical surface 120 with a circular cross-section centered on the central axis X76 of the retaining member 76. The holding member 76 has two

end surfaces

121, 123 perpendicular to the axis X76, which face the cover 66 and the end wall 82, respectively, so that the holding member 76 is fixed within the housing H26 in a longitudinal direction parallel to the axis X60.

The main body 60 has an opening O26, and the opening O26 is formed on the side 122 of the main body portion 62 and on the edge of the cover 66, and connects the housing H26 to the outside of the main body 60. W26 represents the width of opening O26, which is greater than distance d 2'.

In the mounted configuration of the retaining device 26 at one longitudinal end of the clamping rail 22, the openings O22 and O26 extend adjacent to each other along the axis x 22.

Axis Y60 is perpendicular to side surface 122. Z60 defines another transverse axis of body 60 that is perpendicular to axes X60 and Y60 and parallel to side surface 122. The axis Z60 is parallel to the longitudinal direction of the through hole 86 and parallel to the longitudinal axis a90 of the shuttle 90. The width W26 is measured parallel to the axis z 60. The axes X60, Y60, and Z60 are tangent.

The outer surface 120 of the retaining member 76 mates with the inner cylindrical surface 80 defining the housing H26, the retaining member 76 having the possibility of making a limited amplitude of movement within the housing H26 only in the direction of the axis Z60. In other words, as can be seen by a comparison of the two upper positions shown in fig. 5, the retaining member 76 can move axially along the axis Z60 within the housing H26 with a limited amplitude. When the retaining device 26 is mounted at one end of the clamping rail 22, the retaining member 76 is accommodated within the housing H26 and cannot move away from the housing H26 in a lateral direction parallel to the axis Y60 and thus parallel to the axis Y22. In general, the housing H26 forms a guide housing that guides the holding member 76 to rotate about the axes X60 and X76 when they are superimposed.

Retaining member 76 defines a central notch 124 that extends from end surface 121 to end surface 123 and extends between two planar and

parallel surfaces

126 and 128 that are parallel to axis x76 and non-tangential. The axis X76 passes through the notch 124. The retaining member 76 has a base 130 and two

branches

132 and 134 that define the

flat surfaces

126 and 128 on either side of the recess 124, respectively. The recess 124 opens on the cylindrical outer surface 120 in a direction opposite the bottom 130. The recess 124 is configured to receive the intermediate portion 46 of the clamping bar 24.

At each longitudinal end of the clamping rail 22, a holding device 26 is mounted when assembling the yarn clamping device. The yarn clamping device thus comprises two holding devices 26, two holding members 76 and two shuttles 90. Axes X22 and X60 are aligned and superimposed, axes Y22 and Y60 are parallel, and axes Z22 and Z60 are parallel.

Before the clamping bar 24 is inserted into the clamping rail 22 of the yarn clamping device 20, the yarn layer L1 or L2 is pulled out of the warp beam so as to extend along the front surface 23 of the clamping rail 22. Between the warp beam and the front surface 23, the yarns 200 of each yarn layer L1 or L2 are guided by one of the two rollers 138.

When the clamping bar 24 is mounted in the yarn clamping device 20, its central portion 42 is inserted through the opening O22 into the clamping volume V22 and has a translational movement parallel to the axis Y22, as indicated by the arrow a1 in fig. 4. This translational movement a1 causes the two intermediate portions 46 of the same clamping bar 24 to be inserted through the opening 026 into the housing H26, in particular into the recess 124, also by translating along the axis Y60 (also indicated by the arrow a1 on fig. 5) of the two retaining means 26. Thus, each opening O26 is a passage opening for the clamping bar 24.

This assumes that each retaining member 76 is in the release position, oriented as shown in the upper portion of fig. 5, with its

surfaces

126 and 128 parallel to axis y 60.

As can be derived from fig. 4, regardless of the position of the retaining member 76 in the housing H26, the or each opening O26, O26 extends further away from the plane containing the axes X60 and Z60 than the opening O22 extends further away from the plane containing the axes X22 and Z22. In other words, the opening O22 corresponding to the clamping volume V22 is located between the clamping volume V22 and the opening O26 corresponding to each housing H26 along the transverse direction Y22 or Y60.

Further, the branch 132 of the retaining member 76 extends away from the axis X76 toward the opening O26, extending further to the opening O22 than the clamping volume V22.

In this position, the retaining member 76 does not obstruct the passage of the clamping bar 24 out of the recess 124.

Thus, when the clamping lever 24 is moved in the direction of arrow a1 in fig. 4 and 5, the flat face 52 of its intermediate portion 46 begins to slide over the flat faces 126 of the two retaining members 76 before its central portion 42 enters the clamping volume V22 through the opening 22. Thus, the two planes 126 form a guiding surface of the central portion 22 towards the clamping volume v 22.

At the end of the translational movement represented by the arrow a1, in an extraction movement opposite to the introduction movement of the clamping lever represented by the arrow a1, the clamping lever 24 is in an insertion position in which the lever 24 can still pass through the opening O22, in which insertion position the plane 50 faces the inner surface 36.

At this stage, the retaining member 76 of each retaining device 26 is in the release position shown at the top of fig. 5, in which it does not obstruct the movement of the respective intermediate portion 46 along axis Y60, in the direction of arrow a1 or in the opposite direction.

In this release position, which corresponds to the retracted position of the shuttle 90, the rounded end 94 of the shuttle 90 engages the retaining member 76 by sliding contact with the outer cylindrical surface 120 of the retaining member 76. And does not prevent any rotational movement of the retaining member 76 about its axis x 76. The retaining device 26 is in the released configuration.

When the clamping bar 24 is inserted into the clamping volume V22 and the housing H26 by translation along the axes Y22 and Y60 represented by the arrow a1, its central portion 42 pushes the yarn 200 of the respective layer L1 or L2 towards the bottom of the clamping volume V22 through the opening 022.

A torque may then be applied on at least one end 44 of the clamping lever 24 to rotate the lever about its longitudinal axis X24 in a clamping direction within the clamping volume V22. The clamping direction may be defined as a rotational direction which brings the clamping lever 24 relative to the clamping rail 22 successively from an insertion position shown at the top of fig. 4 and 5 into an intermediate position shown in the middle of fig. 4 and 5 and into a clamping position shown at the bottom of fig. 4 and 5. The clamping direction is a rotational direction about the axis X24 in the direction of arrow R2 in fig. 4 and 5.

The axes X22 and X24 now coincide.

The inner cylindrical surface 30 and the circular surface 48 cooperate for guiding the rotational movement of the clamping rod 24 in the clamping volume v 22. The inner surface 36 projects at least partially into a cylindrical volume having a diameter equal to the maximum dimension of the clamping lever, i.e. equal to the diameter D1, and which is defined in the clamping volume V22 about the axis of rotation X24 of the clamping lever 24.

Since the intermediate portion 46 and the retaining member 76 are connected together rotationally about the axes X24 and X76, this is on the one hand by the form-fit between the

surfaces

52 and 126 and, on the other hand, by the surface 54 and the surface 128, such a rotation in the clamping direction R2 of the clamping lever 24 causes a corresponding rotation of the retaining member 76 about the same axis with the same angular amplitude, also indicated by the arrow R2 on fig. 5. Thus, the cylindrical surface 120 is fixed to rotate with the clamping rod about the axis X24. During rotation in the clamping direction R2, the outer cylindrical surface 120 of the holding member 76 slides over the circular end 94 and the inner cylindrical surface 80 of the shuttle 90, which cannot move in the transverse direction y 22. The retaining means 26 is still in the released configuration.

This brings the clamping bar to the second position shown in the middle of fig. 4 and 5. This position is the intermediate position of the clamping bar 24, in which the yarns 200 pass through the clamping volume V22, but are not blocked within this clamping volume, as long as they are able to slide with respect to the central portion 42.

In this position, the maximum outer dimension d24 of the cross section of the central portion 42 of the clamping bar 24 parallel to the axis Z22 is greater than the distance d2 and less than the diameter d1 due to the non-circular profile of the clamping bar 24. For example d24 equals 35 mm.

W22 denotes the width of the opening O22, measured parallel to the axis Z22, i.e. perpendicular to the axis y 22. W22 equals for example 30 mm. Preferably, W22 is between 75% and 90% of the diameter d 1. W22 is substantially equal to the size of d 2.

In an intermediate position of the clamping bar 24, the portion 30a and the portion 30b face the clamping bar 24 in the direction of the arrow a1 in the transverse direction Y22. In this intermediate position, the outer dimension d24 is strictly greater than the width W22 measured at the same level along the longitudinal axis X22 as the outer dimension d 24. Thus, the clamping bar 24 is locked within the clamping volume V22 along its central portion 42, provided it cannot be withdrawn from this volume by lateral movement of the opening O22 only along the axis y 22. In other words, the difference d3 between the maximum dimension d24 and the width W22, d3a + d3b, is sufficient to produce a holding region on the clamping rail 22 in the clamping volume V22 by the form-fit between the clamping bar and the portion 30a, the 30b serving to block the clamping bar 24 in this clamping volume. This retaining region extends over the entire length of the longitudinal central portion 42 accommodated in the clamping volume V22 and on both sides of the main plane P22, as indicated by the two designations d3a and d3b on fig. 4, which avoids bending of the clamping bar 24, in particular if its length is greater than 3 meters.

In this position, on the other hand, the second branch 134 of the retaining member 76 is interposed between the clamping bar 24 and the opening 26, thereby preventing the intermediate portion 46 of the clamping bar 24 from passing through the notch 124 and also retaining the respective intermediate portion 46 within the housing H26. Thus, this position is the holding position of the holding member 76.

d4 denotes the distance, measured in the retaining position of the retaining member 76 parallel to the axis Z60, between the free end 135 of its branch 134 and the edge 63 of the body portion, which edge 63 defines the opening O26 immediately adjacent to the through hole 86. The distance d4 is strictly less than the width W26, preferably less than 75% of the width. For example, d4 equals 16 millimeters and W26 equals 30 millimeters.

D24' denotes the maximum outer dimension of the cross section of the intermediate portion 46 parallel to the axis Z60 in the intermediate position of the clamping bar 24, i.e. in the retaining position of the retaining member 76. The dimension d24' is preferably less than or equal to the maximum dimension d 24. This dimension d24' is strictly greater than the distance d4 so that the clamping lever 24 is locked within the housing H26 by the retaining member 76. In other words, the remaining width of opening O26 through intermediate portion 46 (also referred to as the "apparent width") is reduced to a distance d4 that is less than dimension d 24'. This prevents the clamp lever 24 from being withdrawn from the housing h 26.

Due to the rotation of the retaining member 76, the shuttle 90 no longer abuts the outer cylindrical surface 120 such that its movement toward the housing H26 is no longer restricted by the retaining member 76. Thus, the reciprocating motion 90 is urged by the spring 92 until contact between its collar 96 and shoulder 98 such that its rounded end 94 projects within the housing H26 in the blocking position. This occurs automatically, without action by the operator, during rotation of the holding member 76 in the clamping direction of arrow R2, due to the action of the spring 92. When the clamping lever 24 performs a rotational movement in the clamping direction from the insertion position to the intermediate position, a movement of the shuttle 90 from the retracted position to the blocking position takes place automatically, which movement is relative to the retaining member 76 and the clamping lever 24. In this blocking position and with the clamping lever 24 in the intermediate position, the shuttle 90 is in contact with the holding member 76 in the circumferential direction about the axes X24 and X76.

In this configuration, the shuttle 90 forms an obstacle to rotation of the holding member 76 about the axis x76 in the direction of the arrow R3 on fig. 5. In other words, once it has reached the retaining position, with the shuttle 90 forming an obstacle in the blocking position, the retaining member 76 cannot be returned to its release position by rotation in the direction R3 opposite to the clamping direction R2, since this rotational movement is blocked by the shuttle 90 forming an obstacle. Thus, the shuttle may also be referred to as an obstacle to the retaining member 76. The holding device 26 is then in the holding configuration.

Since the holding member 76 is connected rotationally about the axes X24 and X76 with the clamping lever 24 by the form-fitting of the

surfaces

52, 54, 126 and 128, the holding member 76 is blocked by the obstacle formed by the shuttle 90, preventing the clamping lever 24 from rotating in the direction of the arrow R3.

The retaining member 76 serves as an interface between the obstruction 90 and the portion 46 of the clamping bar 24.

As can be seen from the bottom of fig. 4, in the clamping position, the clamping lever 24 engages with the rubber profile 34 on one side of the main plane P22 only, with the yarn 200 in the middle thereof, while the clamping lever 24 engages with the clamping rail 22 on the other side of the main plane P22 only, with the yarn 200 in the middle thereof. The rounded surface 48 faces the inner surface 36. The

portions

30a and 30b and the rounded surface 48 fit together in a form-fitting manner with the yarn 200 in between. The clamping lever 24 partially protrudes through the insertion/extraction opening O22 and protrudes from the clamping rail 22. In particular, as can be seen at the bottom of fig. 4, the clamping bar 24 projects from the clamping rail 22 only over a part of the non-zero distance d5 of the front surface 23 located on the same side of the main plane P22 as the inner surface 36. The clamping bar 24 does not project from the clamping rail 22 nor beyond the portion of the front surface 23 located on the other side of the main plane p 22.

Even if the holding member 76 is blocked in the direction of the arrow R3, the obstacle 90 does not block the holding member in the clamping direction R2, so that in the holding configuration of the holding device 26, the clamping lever 24 can be moved from the intermediate position into the clamping position shown in the bottom of fig. 4, in which the yarn 200 is clamped between its central portion 42 and the inner surface 36 of the rubber profile 34, if the abovementioned torque continues to be applied in the direction of the arrow R2. In practice, the shape and position of the rubber profile 34 are such that, when it is in the clamping position, the joining edge 49 between the

surfaces

48 and 50 of the central portion 42 penetrates slightly through the rubber profile 34 at the level of the inner surface 36. This is with the yarn 200 in between, which ensures proper clamping of the yarn 200 within the clamping volume v 22.

From the intermediate position to the clamped position, the shuttle 90 forming the obstacle does not move relative to the main body 60 and there is no lateral movement of the holding member 76 along axis y 20.

In the clamping position of the clamping lever 24, the holding element 76 is in a third position which is different from the holding position, since the clamping lever 24 and the holding element 76 are connected between the intermediate position of the clamping lever 24 and the clamping position and move rotationally together.

The tensioning device 140 belongs to the frame 12 and allows the position of the upper beam 16A to be adjusted along the column 14, as indicated by the double arrow a2 on fig. 7 and 8. In practice, one tensioning device 140 is mounted between each post 14 and the upper beam 16A. The direction of the adjustment movement of the upper beam 16A is the direction of approach/distance relative to the lower beam 16B, which is perpendicular to the longitudinal direction of these beams. This direction is parallel to the axes Z22 of the clamping rails of the four thread tensioning devices 20. Each tensioning device 140 comprises a spindle 142 which is in fact movable and connected to the upper beam 16A by means of a bracket 144. A first spindle can be operated by an operator via a ratchet wrench, not shown, and its rotational movement is transmitted to the other spindles forming the driven spindles by one or more synchronization chains 146.

The lower beam 16, on the other hand, is mounted on the column 14 without any possibility of movement.

Thanks to the tensioning device 140, it is possible to adjust the distance between the two clamping devices 20 of a pair of clamping devices parallel to their axis Z22, and thus the tension of the yarns of the first and second layers L1 and L2.

The yarn framework 12 is mounted on some columns 150 of the fixed structure 4 of the drawing-in machine 2, with variable inclination with respect to the fixed structure. This is obtained by a system of articulated levers 152 articulated on the uprights 150. Each lever 152 is associated with a gas spring 154. Thus, when the yarn frame 12 is substantially horizontal, the operator can prepare the clamping and tensioning of the layers L1 and L2, i.e. will orient the opening O22 of the clamping rail 22 of the yarn frame 12 upwards, which faces the top in the vertical direction. Before the drawing-in process is started, the yarn frame is tilted backwards to the vertical drawing-in position shown in figures 2, 7 and 8.

Alternatively, the yarn frame 12 may be stationary relative to the fixed structure 4.

The relative movement of the drawing-in unit 8 with respect to the yarn frame 12 results from the fact that the drawing-in unit can be moved along the longitudinal axis X12 of the yarn frame 12 during the drawing-in process, while the yarn frame 12 remains stationary. Alternatively, the drawing-in unit is stationary and the yarn frame moves during the drawing-in. The user may use the teachings of US-A-5381594 or EP-A-2199443.

In the case shown in the figures, in which the drawing-in process is carried out with a single drawing-in unit 8 with yarns 200 taken from two warp layers L1 and L2, the lower beam 16 supports two clamping devices 20 and the upper beam 16 supports the other two clamping devices. As described above.

In the case of a drawing-in process using yarns 200 taken from a single warp layer, a single clamping device 20 may be mounted on each beam 16.

In the drawing-in machine shown, the clamping rail 22 of each clamping device 20a2 and 20B2 of the second pair of clamping devices is movable along the respective beam that supports it, i.e. parallel to its longitudinal axis x 22. In this regard, the clamping rail 22 is controlled by a dedicated adjustment device 160. The adjustment device 160 comprises a nut 162 which is in threaded engagement with a spindle 164 and is guided along an axis x22 by a guide rail 165 fixed to the main structure of the yarn frame 12. Bevel gear 166 driven by crank handle 168 drives rotation of spindle 164 so that nut 162 is displaced in a direction parallel to the axis X22 of the clamping rail, as indicated by arrow A3. In fig. 2, the adjusting device 160 is shown separated from the yarn frame 12 and on a larger scale. In fig. 9, the upper adjusting device 160 is shown in its use configuration on the thread frame 12.

Each adjustment device 160 also includes a bolt 170 threaded into its nut 162. The bolt 170 of the lower adjustment device 160 is not shown in fig. 2. Each bolt 170 is configured to be threaded into a threaded bore 172 near one end of the clamping rail 22 of the yarn clamping device 20a2 or 20B 2.

Each longitudinal end of the clamping rail 22 has a cutout 174 for receiving a telescoping support 176.

The cooperation of the bolt 170 and the threaded hole 172 allows to transfer the translational movement of the nut 162 of the adjusting device 160 along its track 165 into the clamping track 22 of the associated yarn clamping device 20a2 or 20B2, which translates along its longitudinal axis x 22.

As shown in fig. 10, an interface 179 is inserted longitudinally between the body 60 of the holding device 26 and the longitudinal end of the clamping rail 22 on the longitudinal side of the adjustment device. The interface 179 is secured to the body 60 by screws 28. The interface is fastened to the nut 162 by a screw 181 which extends through the nut 162 parallel to the bolt 170 and engages in a threaded hole of the interface. Then, since the nut 162 is fixed to the end of the clamping rail 22 and connected with the interface 179, the adjacent holding device 26 is indirectly fixed to the clamping rail 22.

In order to guide the movement of the clamping rail 22 of one of the yarn clamping devices 20a2 and 20B2 relative to the associated beam 16, each longitudinal beam 16 is provided with guide projections 180 which are regularly distributed along the entire length of the beam 16. In practice, a set of two protrusions 180 arranged above and below the clamping rail 22, respectively, together form a guide set 182. As shown in fig. 9, the guide sets 182 are distributed along the length of the beam 16. The two protrusions 180 of the guide group 182 are aligned along a direction parallel to the yarns 200 in the yarn layer L1 or L2, i.e. along a direction parallel to the axis z 22.

On the other hand, each clamping rail 22 is provided with two longitudinal grooves 184 configured for receiving each projection 180 and sliding thereon when the nut 162 moves along the rail 165, if this clamping rail 22 is associated with the adjustment device 160.

Due to the longitudinal adjustment of the position of the yarn clamping devices 20a1 and 20a2 of the second pair of yarn clamping devices, the position of the yarns of the second yarn layer L2 relative to the yarns of the first yarn layer L1 can be adjusted in the longitudinal direction of the beams 16 and at the level of the yarn separation zones YSZ located between the upper and lower beams 16.

Furthermore, the upper yarn gripping device 20a2 of the second pair of yarn gripping devices is partly detachably mounted on the main structure of the yarn frame 12, in particular on its upper beam 16. In order to be able to mount the clamping rail 22 detachably on the yarn framework 12, the walls of the two longitudinal grooves 184 are regularly interrupted along the length of the clamping rail by cutouts 186. The distance between two adjacent cutouts 186 along the axis X22 is the same as the distance between two adjacent guide sets 182 along the longitudinal direction of the upper beam 16A. The length L186 of the cut-out, measured parallel to the axis X22, is greater than the length L180 of each projection 180, measured parallel to the longitudinal direction of the beam 16A.

This allows the clamping rail 22 of the yarn clamping device 20a2 to be introduced between the two protrusions 180 of the guide group 182 in a direction parallel to the axis Y22 and perpendicular to the longitudinal direction of the upper beam 16A after the cutouts 186 have been aligned with these guide groups 182. This is indicated by arrow a4 on fig. 9 and 10. The clamping rail 22 may then be slid along its longitudinal axis X22 to engage the protrusion 180 into the longitudinal groove 184 to block the clamping rail 22 on the upper beam 16 along the axis Y22 and the axis Z22 by a bayonet movement. After such bayonet movement, the threaded bore 172 is aligned with the bolt 170 and the connection between the nut 162 and the clamping rail 22 may be made by the bolt.

Preferably, the clamping rail 22 of the thread clamping device 20a2 is already fastened to the holding device 26 by means of screws 28 on its longitudinal side opposite the threaded bore 172 and the adjusting device 160 before the cooperation with the guide device 182. The interface 179 and the holding means 26, which are located on the longitudinal sides of the adjusting device 160, have been fastened to the main structure of the yarn framework 12.

The thread clamping device 20a2 is partially detachably mounted on the longitudinal beam 16 of the thread frame 12, which requires only a threaded connection formed by the screw 170 and the threaded bore 172 to mount the clamping rail 22, which is already equipped with a holding device 26, on the main structure of the thread frame 12.

Each holding device 26 of the yarn clamping device 20a2 or 20B2 follows the translational movement of the clamping rail when it is fixed to the associated movable clamping rail 22 in the longitudinal direction.

However, this is not mandatory. According to an alternative embodiment of the invention, not shown, the holding devices 26 can be stationary relative to the yarn frame 12 and the intermediate portion 46 of the clamping bar 24 slides within them when the clamping rail 22 moves between them along its axis X22.

In another alternative embodiment of the invention, not shown, the removable yarn clamp is the lower yarn clamp 20B2 mounted on the lower beam 16B as the yarn is pulled from the beam first on the lower beam 16B side and then on the upper beam 16A side.

In practice, in order to avoid as much as possible interference with the yarn distribution within the yarn layer L1 along the width of the yarn layer, the length L180 of each projection 180 in the longitudinal direction of the upper beam 16A should be kept as small as possible. In fact, as shown in fig. 9 and 10, the yarn separation at the level of the guide group 182 results in a disturbance zone Zd in the yarn distribution along the yarn width of the yarn layer L1. Keeping length L180 small may reduce these interference regions.

Preferably, all clamping rails 22 of the four yarn clamping devices 20 are extruded from the same die. They all have the same constant cross section and in particular have two opposite longitudinal grooves 184. In this case, as shown in fig. 7 and 8, some of the protrusions 180 located between two adjacent clamping rails 22 mounted on the same beam 16 engage in a first longitudinal groove 184 belonging to a first clamping rail 22 of a first pair of yarn clamping devices 20 and in a second longitudinal groove 184 belonging to an adjacent clamping rail 22 of a second pair of yarn clamping devices 20.

A method of clamping a yarn 200 of a yarn layer L1 or L2 with a yarn clamping device 20 is described below in connection with a single yarn clamping device 20.

At the beginning of the process, the yarn 200 is pulled out of the warp beam so as to cover the front surface 23 of the clamping rail 22 forming the opening 22. In this configuration, the yarn 200 is located outside the clamping volume V22 of the yarn clamping device 20.

At this stage, both maintenance devices 26 are in the released configuration. For each retaining member 76, the notch 124 faces the opening O26.

In the released position of the two retaining members 76, the clamping bar 24 can be inserted in the clamping volume V22 and the housing H26 by translation parallel to the axes Y22 and Y60 in the direction of the arrow a 1. Due to the direction of this translation, the clamping lever 24 pushes the yarns and deflects them into the clamping volume v 22. If, during the insertion movement of the clamping bar 24, the clamping bar 24 extends parallel to the axis X22, the effect of the clamping bar 24 on the yarn 200 is the same over the width of the yarn layer parallel to the axis X24. During this translational movement, once the intermediate portion 46 of the clamping rod 24 passes through the opening 026, the plane 50 of the clamping rod 24 is oriented towards the rubber profile 34 and the plane 54 slides along the plane 126.

The movement of the clamping lever 24 is directed to the clamping volume V22 through the notch 24 formed in the retaining member 76. In particular, during the translational movement represented by the arrow a1, the

planes

52 and 54 of the intermediate portion 46 of the clamping bar 24 slide along the

planes

126 and 128 of the holding member 76 and are guided towards the bottom 130 of the notch 124. Since the distance between the opening O26 and the axis X60, measured along the axis Y60, is greater than the distance between the opening O22 and the axis X22, measured along the axis Y22, the guiding fit between the

portions

46 and 76 begins before the central portion 42 enters the clamping volume V22. This movement in the direction of arrow a1 continues until the surface 58 of the intermediate portion 46 abuts the bottom 130 of both notches 124.

Since the distance d2 is slightly less than the width W22 and the distance d2' is less than the width W26, translational movement of the rod in the direction of arrow a1 through the openings O22 and O26 is possible. In other words, in the release position of the holding element 76, the clamping lever 24 can be completely aligned with the openings O22, O26 without any part of the yarn clamping device 20 in between.

The clamping lever 24 is then in the inserted position in the clamping rail 22. From this position, the rod 24 can still be withdrawn from the clamping volume V22, if desired. The retaining member 76 is in its release position.

From the insertion position of the clamping lever 24, the holding member 76 is pushed by the rounded end 94 of the shuttle 90, which results in a slight displacement of the holding member 76 in the housing H26 parallel to the axis Z60 in a direction away from the supporting plate 64. The outer cylindrical surface 120 of the retaining member 76 abuts the portion of the inner cylindrical surface 80 opposite the through bore 86. This allows the rotation of the retaining member within housing H26 to be guided by the mating of

surfaces

80 and 120.

The axes X22, X24, X76 and X60 are then superimposed and form a common longitudinal axis X20 of the yarn clamping device 20. Each longitudinal beam 16 extends parallel to the common longitudinal axis x 20.

Then, the clamp lever 24 is rotated about the common center axis X20 in the clamping direction indicated by the arrow R2 by about 40 °. This brings the clamping lever 24 into an intermediate position shown in the middle part of fig. 4 and 5. This also brings the retaining member 76 into its retaining position shown in the middle portion of fig. 5. During this movement, the outer cylindrical surface 80 of the retaining member 76 slides in contact with the rounded end 94 of the shuttle 90 until the ends 133 of its branches 132 move angularly relative to the obstruction formed by the shuttle 90. In this position, the spring 92 pushes the obstacle formed by the shuttle 90 towards the housing H26, so that it protrudes from the inner cylindrical surface of the housing H26 and its collar 96 abuts the shoulder 98, as described above. Any rotational movement of the holding member 76 in the direction indicated by the arrow R3 and opposite to the clamping direction R2 is then prevented by the shuttle 90 forming an obstacle, on which the end 133 abuts.

In the intermediate position of the clamping bar 24, there is a gap between the surface 36 and the surface 4850, which allows the yarn 200 to also move within the clamping volume v22 in its direction of extension. Then, as explained below, the yarn 200 may be distributed along the axis X22 and/or the tension of the yarn may be adjusted, if desired.

In the retaining position of the retaining member 76, the intermediate portion 46 of the clamping lever 24 is blocked within the housing H26 by the retaining member due to the difference between the maximum dimension d24' and the remaining width d4 of the opening O26, as described above.

When the holding member 76 is rotated in the clamping direction R2 between the clamping position and a third position corresponding to the clamping position of the clamping bar 24, it further reduces the remaining width of the passage for the clamping bar 24 out of the notch 124. The width is equal to zero in the third position of the holding member 76, as shown in the lower part of fig. 5.

During the middle position of the clamping lever 24 and during the rotation from this middle position to the clamping position of the lever in the clamping direction R2, the yarn exerts a force on the clamping lever 24 which tends to push the clamping lever 24 out of the clamping volume V22 through the openings O22 and O26, so that the clamping lever rotates in the direction opposite to the clamping direction. Thanks to the retaining member 76, the intermediate portion 46 is retained within the housing H26, so that the central portion 42 is retained within the clamping volume V22 in the intermediate position. In other words, the retaining member 76 opposes the force exerted by the yarn 200 on the clamping bar 24.

In the intermediate position, the obstruction formed by the shuttle 90 does not prevent further rotation of the retaining member 76 in the clamping direction R2 toward the clamped position. Thus, as described above, by means of a form fit, the clamping lever 24 can be moved from the intermediate position into the clamping position, wherein the holding member 76 is driven by the clamping lever 24 between these two positions. The shuttle 90 is in its blocking position for all positions reached by the clamping lever 24 relative to the clamping rail 22 during the rotational movement between the intermediate position and the clamping position in the clamping direction R2.

The third position corresponds to a rotation of the holding member 76 about the common axis X20 of about 90 ° with respect to the release position. Between the intermediate position and the clamping position of the clamping lever, the minimum distance between the clamping lever 24 and the inner surface 36 is reduced. In the clamping position, and as described above, this minimum distance is such that the yarn 200 is pressed between the clamping bar 24 and the inner surface 36 of the rubber profile 34, which ensures that the yarn 200 is regularly clamped along the length of the clamping rail 22. When clamped, the yarns 200 cannot move within the clamping volume V22 between the inner surface 36 and the clamping bar 24 if they are subjected to the normal action of the warp preparation process, such as a drawing-in process.

In the clamped position, the

planes

50, 52, 54 are globally parallel to the axes Z22, Z60, said axes Z22, Z60 being perpendicular to the transverse direction defined by the axes Y22, Y60.

Between the intermediate position and the clamping position, when the clamping bar 24 is rotated in the clamping direction R2, in the clamping position the difference d3 between the maximum dimension d24 and the residual width W22, equal to the sum of the differences d3a and d3b indicated in the center of fig. 4, is still sufficient to form a holding region in the clamping volume V22 for blocking the clamping bar 24 in this volume.

In order to release the clamping action of the clamping lever 24 on the yarn 200, the lever 24 is folded back about the common axis x20 in the direction R3 opposite to the clamping direction. During this movement, the retaining member 76 retains the respective intermediate portion 46 within the volume H26. When the intermediate position is reached again, the obstacle formed by the shuttle 90 prevents the holding member 76 from rotating further in the direction of the arrow r3, since the holding means is still in the holding configuration. The operator can then push one or both of the two transverse pins 104 protruding from the

slots

106 and 108 towards the support plate 64, overcoming the elastic force of the spring 92. This returns the shuttle 90 to the retracted position. The barrier is retracted in the through-hole 86, the retaining device is in the released configuration and no longer resists further rotation of the retaining member in the direction of arrow R3 opposite the clamping direction of arrow R2. This allows the retaining member 76 to return to its release position, wherein the outer cylindrical surface 120 of the retaining member 76 slides over the rounded end 94 of the shuttle 90.

The operator can move the shuttle 90 from its blocking position to its retracted position for all positions relative to the clamping rail 22 reached by the clamping lever 24 during the rotational movement between the intermediate position and the clamping position in the clamping direction R2.

When the retaining member 76 is in its release position, the operator can release the transverse pin 104 and the rod 24, which returns to its insertion position, can be extracted from the clamping volume V22 and the two housings H26 by a translational movement through the openings O22 and O26 in the direction opposite to one of the arrows a 1.

During the optional loosening process, the clamping lever 24 can be rotated in the clamping direction of arrow R2 from its clamping position to its insertion position with the holding device 26 still in the holding state. In this case, the end 135 of the branch 134 abuts against the rounded end 94 of the shuttle 90, and this end 135 pushes the shuttle inside the through hole 86 against the elastic force of the spring 92. This brings the outer cylindrical surface 120 into sliding contact with the rounded end 94. The barrier 90 returns to the retracted position and the retaining device 26 is in the released configuration. As the rotational movement of the clamping lever 24 in the clamping direction of the arrow R2 continues, it allows the holding member 76 to reach a release position in which the clamping lever 24, returning to its insertion position, can be removed from the volume V22 and the housing H26, as in the first unclamping process.

In a second release process, the clamping lever 24 and the holding member 76 are opened 360 ° in the direction of the arrow a1 between the insertion of the clamping lever 24 into the volume V22 and the housing H26, and the clamping lever is removed from these volume and the housing in the direction opposite to the arrow a 1.

A method for clamping and tensioning the two yarn layers L1 and L2 with the yarn frame 12 will be described below.

First, the detachable yarn clamp 20a2 is partially removed from the upper beam 16A of the yarn frame 12 when the yarn 200 of the first layer L1 is pulled from the warp beam and placed in front of the front surface 23 of the clamping rail of the first pair of yarn clamps 20a1 and 20B 1. In this configuration, the yarn 200 extends along a yarn extending direction, which is vertical in fig. 2 to 5 and 7 to 10, and the yarn clamping devices 20 are spaced apart from each other along the direction. These yarns 200 are stretched so that they extend at least to the height of the brushroll 189 extending parallel to the beam 16 below the lower beam 16B. The cooperation between the yarn and the brush roller 189 causes friction on the yarn which contributes to the yarn distribution along the axis X22 of the two yarn clamps. The telescopic support 176 of each of the two yarn clamping devices 20 is then brought into the extended position shown in broken lines in fig. 7, and the clamping bar 24 is placed on each of these supports in front of each clamping rail 22 of the pair of yarn clamping devices. Said plane 50 is directed towards the other clamping bar 24 of said first pair of yarn clamping devices. At this stage, each clamping bar 24 is located outside the clamping volume v 22.

The operator then moves each clamping lever 24 into the associated volume V22 and housing H26, with translational movement in the direction of arrow a1 toward its insertion position.

The operator then engages a wrench with the end 44 of each clamping bar 24 to bring each clamping bar 24 into its neutral position. In the position of the two clamping bars 24, the operator can distribute the yarn 200 of the first layer L1 in the longitudinal direction of the beam 16. In the position of the clamping lever 24, the yarns 200 of the first layer L1 do not have the same tension in this layer, since they do not cooperate equally with the brush roller 189.

Beams

16A and 16B may be spread relative to each other by tensioner 140 to level the yarn tension in yarn layer l 1. In summary, the intermediate position enables a regular tension in the yarn layer l 1.

The operator can then rotate the two clamping levers 24 to bring them into their clamping position. A clamped configuration of the yarns 200 of the first layer L1 is achieved. The operator releases the tensioning device 140 to release the tension in the first yarn layer L1.

In a variant embodiment, one of the two clamping bars 24 cooperating with the first layer L1 is first rotated in the clamping position, and then the operator uses the tensioning device 140 to achieve a regular tension in the yarn layer L1 before clamping the other of the two clamping bars 24.

Then, the yarns 200 of the first yarn layer L1 located at the longitudinal level of the guide groups 182 are divided and arranged on both sides of each guide group 182, as shown by the zone Zd on fig. 9 and 10.

A guide bar 188 is mounted on the upper beam 16A to force the yarn of the first layer L1 along a path adjacent the beam 16A and the yarn clamp 20a1 and maintain an empty volume for receiving the yarn clamp 20a 2.

The yarns of the first warp yarn layer are cut directly under the lower yarn gripping means 20B1 of the first pair and no longer engage the brushroll 189.

Each nut 162 is brought to its intermediate position along the length of its adjustment spindle 164 and guide rail 165. The yarn clamping device 20B2 is moved correspondingly along its common axis x 20. The clamping rail 22 of the detachable thread clamping device 20a2 is then engaged with the guide 182 and screwed by means of the bolt 170 with the nut 162 of the associated adjusting device 160, as explained above.

The yarn 200 of the first layer L1 is thus inserted between the clamping rail 22 of the detachable yarn clamping device 20a2 and the upper beam 16A, as shown in fig. 7 and 8.

The yarns 200 of the second warp yarn layer L2 are pulled from the warp beams to the brush roller 189 at the contact of the front surfaces 23 of the two clamping rails 22 of the second pair of clamping devices 20.

For the first layer, the telescopic support 176 is extended and brought into the position shown in broken lines in fig. 7, and the clamping bars 24 are placed on these supports with the plane 50 facing the other clamping bar 24 of the second pair of yarn clamping devices. And then pushed in the direction of arrow a1 within the two clamping rails 22 and rotated as explained above. When the clamping bar reaches its intermediate position, the operator can distribute the yarn 200 of the second warp layer L2 in the longitudinal direction of the beam 16, balancing the tension of the yarn along the width 200 of the second warp layer L2 to be equivalent to the tension of the yarn layer L1 with the tensioning device 140.

The operator can then rotate each clamping lever 24 of the yarn clamping devices 20a2 and 20B2 in the rotational clamping direction in order to clamp the yarn 200 of the second warp yarn layer L2 in the clamping position in the clamping rails 22 of both clamping devices of the second pair of yarn clamping devices.

The tensioning device 140 is then used to spread the two beams 16 apart in order to increase the tension of the yarns in the warp layers L1 and L2.

At the end of the preparation of the warp layers, the two warp layers extend substantially in the same plane between the upper clamping rail 22 and the lower clamping rail 22, as shown in figures 7 and 8.

The two warp layers L1 and L2 are then in the configuration of fig. 2, in which they extend substantially in the same vertical plane, and the yarn frame 12 is vertical and ready for use of the drawing-in unit 8 in the drawing-in machine 2.

In this connection, the threading unit 8 may have a single separation device for the two layers L1 and L2, as disclosed in CN-U-211036281, with a separation rope between the two layers L1 and L2. In the case of warp layers L1 and L2 having to be moved relative to each other in a longitudinal direction parallel to axis X20 during the drawing-in process, each clamping rail 22 associated with the adjusting device 160 can be moved in the direction of arrow A3, which is parallel to the longitudinal direction of the beam 16. This allows the second yarn layer L2 to slide parallel to the longitudinal direction of the beam 16 in the direction of arrow a3 relative to the fixed structure 4 and the first yarn layer L1. During this movement, the projection 180 guides the translation of the clamping rail 22 relative to the beam 16.

If yarn preparation occurs with the yarn frame in an inclined configuration, the use of telescoping support 176 is not required.

In fig. 9 and 10, the yarn frame 12 is shown in use with a single yarn layer L1, but may also be used with two yarn layers, as shown in fig. 1, 2, 7 and 8. Thus, the yarn framework 12 is universal.

In the second and third embodiments of the yarn clamping device according to the invention shown in fig. 11 and 12, similar elements to those of the first embodiment have the same reference numerals. After that, only the differences from the first embodiment are mentioned. If reference numerals are used in one of the fig. 11 and 12, but not mentioned in the following description, it designates the same parts of the yarn clamping device as the parts having the same reference numerals in the first embodiment.

In the second embodiment of fig. 11, the holding member 76 has an L-shaped cross section, and the obstacle is formed by a rotating lever 90.

The retaining member 76 defines a pocket 124 in the shape of a dihedron having a base 130 and a branch 132 forming a plane 126. The lever 90 is rotatable about an axis 190 fixed relative to the body 60 of the holder 26. The lever 90 is urged by a torsion spring 92 toward the blocking position shown at the bottom of fig. 11. The end 94 of the lever 90 is movable in a housing 602 defined between a main portion 604 of the body 60 and a stem 606 of the body 60 defining the opening 26 adjacent the lever 90. The housing 602 is transverse to the longitudinal axis X24 of the clamping lever 24, and thus to the axis of rotation X20 as defined in the first embodiment.

In its central portion 42 and intermediate portion 46, the clamping bar 24 is hollow and has two outer flat faces 52 and 54 and two

outer faces

56 and 58 in the form of circular arcs whose cross-section is centered on the longitudinal axis X24 of the clamping bar. A dimension d2 defined between the

surfaces

52 and 54 and perpendicular to the

surfaces

52 and 54 is less than the width W22 of the opening O22 as defined in the first embodiment.

When the clamping bar 24 is inserted into the housing H26 of the holder 26 through the opening O26 and into the clamping volume V22 through the opening O22, the flat surface 54 slides on the flat surface 126 in the direction of the top arrow a1 in fig. 11 to the point where the cylindrical surface 56 contacts the bottom 130. In this position, the outer cylindrical surface 120 of the retaining member 76 retains the lever 90 in a retracted position away from its blocking position.

During rotation of the lever 24 in the housing H26 between its insertion position and the intermediate position in the clamping direction indicated by arrow R2, the end 133 of the branch 132 leaves the end 94 of the lever 90. So that the lever automatically reaches its blocking position under the action of the spring force exerted by the spring 92. This movement of the lever 90 between its retracted position and its blocking position occurs with respect to the retaining member 76 and thus with respect to the clamping bar 24. As shown in the center of fig. 11, in the locked position of the lever 90, its end 94 projects into the housing H26. When the clamping bar 24 reaches the intermediate position shown in the centre of fig. 11, the holding member 76 is in the holding position in which the end 133 abuts against the lever 90 in the circumferential direction about the axis X60. In this position, the retaining member 76 is blocked by the lever 90 against rotation in the direction R3 opposite the clamping direction R2. Thus, the lever 90 may also be referred to as an obstacle for the holding member 76. The holding device 26 is then in the holding configuration. In this intermediate position, the clamping lever 24 cooperates with the lever 90 through the retaining member 76 and is blocked by the retaining member 76 against rotation in a direction R3 opposite to the clamping direction R2 about the axis X60 by the contact of the flat surface 54 with the flat surface 126.

In this holding position of this second embodiment, the retaining member 76 does not limit the remaining width of the notch 124. The clamping rod 24 is held in the clamping volume V22 and the housing H76 by the difference d3 between its maximum dimension d24 parallel to the axis Z60 on the one hand and the width W22 of the opening O22 on the other hand. Since the maximum dimension d24 is strictly greater than the width w22, this difference d3 creates a holding region by the form-fit between the clamping lever 24 and the clamping rail 22.

Then, by further rotating the clamping lever 24 in the clamping direction r2, the clamping lever 24 and the holding member 76 can be moved to the clamping position shown at the bottom of fig. 11. In this clamping position, the clamping bar 24 presses the yarn against the inner surface of the clamping volume V22 for clamping.

During movement of the clamping rod 24 between the insertion position and the clamping position, the outer cylindrical surface 120 of the retaining member 76 slides relative to the inner cylindrical surface 80 of the body 60.

In the third embodiment of fig. 12, the holding device 26 includes an obstacle formed by a slide bolt 90, which slide bolt 90 is urged toward the housing H26 by a spring 92, but there is no holding member equivalent to the holding member 76 in the first and second embodiments. In this third embodiment, the barrier 90 is directly fixed within the body 60 against rotational movement about the axis X60. Since it is housed in a through hole 194 drilled directly in this body and extending in a direction parallel to the axis a90 transverse to the longitudinal axis X60 and the axis Y60.

The clamping bar 24 has an outer flat surface 52 and an outer surface 56 in the form of a circular arc whose cross-section is centered on the longitudinal axis X24 of the clamping bar.

In this third embodiment, the holding device is manufactured directly in the clamping rail 22. In other words, the body 60 is formed in a portion of the clamping rail 22 in which the through-hole 194 is drilled.

Here, the obstacle 90 is slidable relative to the housing H26 and the main body 60, and thus slidable relative to the clamping lever 24. In the example of fig. 12, the obstacle 90 is movable between the retracted position and the blocking position along the directions indicated by the arrows a5 and a6, the arrows a5 and a6 being perpendicular to the two axes X60 and X24 and to the direction of introduction of the clamping rod 24 within the housing H26, which is also indicated by the arrow a1 on fig. 12.

In the insertion position, and between the insertion position and the intermediate position, when the clamping lever 24 is rotated in the clamping direction R2, the barrier 90 is in the retracted position with its end 94 in contact with the outer planar surface 52 of the clamping lever 24. The retaining device 26 is in the released configuration.

At the longitudinal height of the obstacle 90, a groove 187 is provided in each intermediate portion 46 of the clamping bar 24, which groove is recessed in the clamping rail 22. In its blocking position, i.e. when the clamping lever 24 is moved between its intermediate position and its clamping position in the clamping direction indicated by the arrow R2, the recess receives the end 94 of the obstacle 90, as in the first embodiment, and when the retaining device 26 is in the retaining configuration. The obstacle 90 is automatically urged in the direction of arrow a5 toward the concave portion 187 by a spring 92 mounted in the through hole 194 and fixed therein, for example, with a plate not shown similar to the plate support plate 64 of the first embodiment.

In this intermediate position, the first surface 191 defining the recess 187 engages the obstacle 90 by abutting directly against the end 94 in the circumferential direction about the axis X20 and in the direction of the arrow R3 opposite to the arrow R2. Since the through hole 194 blocks the rotation of the obstacle 90 about the axis X76 in the direction of the arrow R3 in fig. 5, the clamping lever 24 cannot rotate in the rotation direction R3 opposite to the clamping direction R2. The clamping bar 24 is held in the clamping volume V22 by the difference d3 between the maximum dimension d24 of the bar parallel to the axis Z60 on the one hand and the width W22 of the opening O22 at the same longitudinal level on the other hand. Here, the openings O22 and O26 as defined in the first embodiment are the same.

During movement of the clamping bar 24 between its intermediate position and the clamping position, the obstacle 90 remains in its blocking position, in the recess 187 and in the through hole 194, and does not move relative to the clamping rail 22.

Starting from the clamping position, if the clamping lever 24 is rotated further in the clamping direction R2 towards the insertion position, the second surface 193 defining the recess 187 comes into contact with the inclined surface 93 of the end 94 in order to push the obstacle 90 into its retracted position, in the direction of the arrow a6 visible at the bottom of fig. 12, against the action of the spring 92. This brings the retaining means 26 into its release configuration.

In the drawing-in machine 2 and the warp joining device 3 (type-insertion), the yarn gripping devices 20 of the second and third embodiments may be used instead of the yarn gripping device of the first embodiment.

In a not shown embodiment of the invention, only one yarn clamping device or only some of the clamping devices of the yarn framework are as described in the invention.

In another embodiment, the yarn framework may comprise a single pair or yarn clamping means, in particular if the yarn framework is used for handling a single yarn layer.

In another embodiment, a single yarn clamping device may be used to clamp yarns of different overlapping yarn layers.

In an alternative embodiment not shown, the lowermost and uppermost gripping means 20a2 and 20B2 are fixed to the upper and lower beams 16, which cannot be translated along the axis X22, while the other two gripping means 20a1 and 20B1, i.e. the gripping means operating the first layer L1, are movable along the beams 16 under the action of the adjustment means 160.

The angles of 40 deg. and 90 deg. mentioned above may differ. The first angle may be between 30 ° and 55 ° depending on the position of the inner surface 36 within the clamping volume v 22. The second angle may be between 80 ° and 100 °.

In another alternative embodiment, the yarn clamping device 20 includes a single holding device 26 mounted at the first end of the clamping rail 22 for cooperating with an intermediate portion 46 located proximate to the first end of the clamping bar 24. A rod retainer is located at the second end of the clamping rail for maintaining the second end of the clamping rod opposite the intermediate portion relative to the clamping rail. In this case, the second end of the clamping bar is first inserted into the bar holder, and then the clamping bar is tilted so that its central portion enters the clamping volume and its middle portion enters the housing of the holding device. During insertion of the clamping bar, the bar has no pure translational movement and is inclined with respect to the longitudinal axis of the clamping rail.

In another embodiment, the body 60 is provided with an indexing pin that protrudes in the housing H26 and is configured to engage in a circumferentially limited recess provided on the outer cylindrical surface 120 of the retaining member 76. In order to allow the retaining member 76 to move only within an angular range defined between a release position and a third position reached when the clamping lever is rotated in the clamping direction between its insertion position and its clamping position. In this case, it is impossible for the holding member 76 to rotate by 360 °. Furthermore, in this case, in the insertion position in which the plane 50 of the clamping bar 24 does not face the inner surface 36, insertion of the clamping bar 24 is not possible.

In another embodiment, the direction of translation a90 of the slidable barrier forming member 90 is not parallel to the axis Z20, but is, for example, oblique to the axes Z60 and y 60.

In another embodiment, the spring 92 is omitted. In this case, the obstacle may be weighted such that it can move from its retracted position to its blocking position and remain in the blocking position due to gravity. In this alternative embodiment of the holding device, and if the holding device is manufactured directly in the clamping rail 22 as described in the third embodiment, the holding device may comprise only obstacles.

In another embodiment, the clamping bar is made up of different longitudinal sections (hollow or not) of different cross-sections assembled together.

As shown in fig. 19, the yarn clamping device 20 according to the invention and the yarn framework 12 according to the invention can also be used in a warp tying device 3, wherein two pairs of yarn clamping devices 20 are mounted one above the other in a tying configuration along the axis Z22 of the yarn framework 12. Each pair of yarn gripping devices 20 is dedicated to one warp layer. The yarn frame 12 is configured for guiding a translation of the strapping unit 8' along its longitudinal axis x 12. As is known, for example, from EP- ｃA-1943381, two pairs of yarn clamping devices 20 are movable relative to each other along ｃA longitudinal axis X12 for the relative movement of two layers, which extend in two parallel and spaced apart planes.

The frame 12 may be movable and equipped with rollers 13, as shown in fig. 11, or in an embodiment stationary.

portions

30a and 30b and the rounded surface 48 fit together in a form-fitting manner with the yarn 200 in between. The clamping lever 24 partially protrudes through the insertion/extraction opening O22 and protrudes from the clamping rail 22. In particular, as can be seen at the bottom of fig. 4, the clamping bar 24 projects from the clamping rail 22 only by a partial non-zero distance d5 beyond the front surface 23 located on the same side of the main plane P22 as the inner surface 36. The clamping bar 24 does not project from the clamping rail 22 nor exceeds the portion of the front surface 23 located on the other side of the main plane p 22.

When the yarn 200 is pressed against the rubber profile 34 by the clamping bar 24, the clamping bar 24 passes through the inner surface 36, which leads to a local deformation of the rubber profile 34.

Since the clamping bar 24 is made of a single material, the

surfaces

48 and 50 and the edge 49 are made of metal.

In the clamping position of the clamping lever 24, the lever is oriented about the axis X24 such that its diameter D1 is equal to the maximum outer dimension D24 of its central portion 42, which dimension is parallel to the axis z 22. Thus, in this clamping position, the ratio d24/W22 is strictly greater than 1, wherein the dimension d24 and the width W22 are measured on the same longitudinal level along the longitudinal axis X22, the portion 30a and the portion 30b of the inner cylindrical surface 30 together forming a holding zone for holding the clamping bar 24 within the clamping volume V22, as shown in the bottom of fig. 4.

As shown in fig. 4, the two longitudinal grooves 184 of the track have the same geometry, but are offset along axis y 22.

The flat surface 50 faces the bottom of the clamping volume v 22.

In the second to seventh embodiments of the yarn clamping device according to the invention shown in fig. 11 to 18, similar elements to those of the first embodiment have the same reference numerals. Hereinafter, the differences from the first embodiment will be mainly mentioned. If reference numerals are used in one of fig. 11 to 18, which are not mentioned in the following description, it designates parts of the yarn clamping device which are identical to the parts having the same reference numerals in the first embodiment.

According to one aspect of the invention, which can be taken from fig. 11, in the clamping position of the clamping lever the ratio d24/W22 is strictly greater than 1, wherein the dimension d24 and the width W22 are as defined in the first embodiment. The dimension d24 and the width W22 are measured at the same longitudinal level along the axis of rotation x 20.

In this intermediate position, the first surface 191 defining the recess 187 cooperates with the obstacle 90 by abutting directly against the end 94 in the circumferential direction about the axis X20 and in the direction of the arrow R3 opposite to the arrow R2. Since the through hole 194 blocks the rotation of the obstacle 90 about the axis X76 in the direction of R3 indicated by the arrow in fig. 5, the clamping lever 24 cannot rotate in the rotation direction R3 opposite to the clamping direction R2. In the intermediate position and in the clamping position, the clamping bar 24 is held in the clamping volume V22 by the difference d3 between the maximum dimension d24 of the bar parallel to the axis Z60 on the one hand and by the width W22 of the opening O22 on the same longitudinal level on the other hand. Here, the openings O22 and O26 as defined in the first embodiment are the same as those defined in the first embodiment.

The fourth embodiment shown in fig. 13 to 15 is particularly suitable for the yarn layer of denim yarn. The denim yarn is thicker than the filament yarns of the first three examples. The denim yarn is threaded by means of the drawing-in machine shown in fig. 14 and 15, the yarn frame 12 and the drawing-in unit 8 of which are slightly different from those of the first embodiment.

In this fourth embodiment, in the meaning of the maintenance device 26 of the first embodiment, no maintenance device is provided.

In fig. 13, the rubber profile 34 is located only above the main plane P22, while the clamping rail 22 defines a clamping volume V22 on the other side of the main plane P22 (i.e. below the main plane P22). The rotational clamping direction R2 is counterclockwise in the figures, as in the second embodiment, and clockwise in the first and third embodiments.

The plane inner surface 36 of the rubber profile 34 is oriented towards the opening 22 and has an inclination angle a of between 10 ° and 30 ° with respect to the main plane P22 of the rail 22, which is preferably approximately equal to 16 °. The angle alpha is also defined by the direction of the bottom of the recess 32, since the rubber profile has a rectangular cross section. In particular, for the first embodiment, the inner surface 36 of the rubber profile 34 is also inclined with respect to the axis Z22 and parallel to the axis x 22.

The cross-section of the clamping bar 24 is the same along its entire length. Which defines a circular surface 48 and a flat surface 50 comparable to the

surfaces

48 and 50 of the first embodiment. These surfaces extend up to the two end portions 44 of the clamping bar which are directly adjacent to the central portion 42 without the interposition of an intermediate portion 46.

As shown in fig. 13, the clamping bar 24 is inserted into the clamping volume V22 through the opening 022, as in the first embodiment, up to a position where its longitudinal axis X24 overlaps the longitudinal axis X22 of the clamping rail on the axis of rotation X20. The clamping lever is then rotated about the axis of rotation in the clamping direction R2 by means of a tool, not shown, which has an internal shape complementary to the cross section of the clamping lever 24. Its rotation in the clamping direction R2 continues until the clamping lever reaches the intermediate position shown in the center of fig. 13, in which there is a gap C22 between the clamping lever 24 and the inner surface 36 of the rubber profile 34. This gap C22 allows the yarn to move within the clamping volume v 22. For example, the gap C22 has a non-zero width that is greater than the yarn thickness. The operator can thus use this intermediate position to regulate the redistribution of warp yarns 200 along the longitudinal axis X22, so as to make the yarn tension distribution more uniform along the clamping rail 22. In the intermediate position, the flat surface 50 faces the inner surface 36.

In this intermediate position and the clamping position, the clamping bar cannot be completely withdrawn from the clamping volume V22 through the opening O22 for the same reasons as mentioned in the first embodiment. This is because the ratio d24/W22 is strictly greater than 1 and due to the retention zone formed by the

portions

30a and 30b of the inner cylindrical surface 30. The dimension d24 and the width W22 are measured at the same longitudinal level along the axis of rotation x 20.

Since no holding means are used in this embodiment, the operator holds the clamping lever 24 in the intermediate position by using a tool, not shown, for applying a torque about the rotation axis X20 to counteract the reaction force of the yarn, which tends to rotate the clamping lever in the opposite direction to the rotation direction r 2.

Further rotation in the direction of rotation R2 from the intermediate position shown in the center of fig. 13 allows reaching the clamped position shown in the bottom of fig. 13.

It is also possible to reach the clamping position from the insertion position by rotating in a direction opposite to the direction of rotation r 2. However, this does not allow for reaching and using intermediate positions.

In this fourth embodiment, the parameters defined by the first embodiment have the following values:

d1 ═ 24.8 mm;

d2 ═ 19 mm;

d24 ═ 24 mm;

w22 ═ 21 mm;

d30 ═ 25 mm;

d31 ═ 28 mm;

a rotation angle R2 in the clamping direction between the insertion position and the intermediate position of 50 °; and

the angle of rotation R2 in the clamping direction between the intermediate position and the clamping position is 40 °.

Also, the following values are given,

the ratio W22/D1 is in the range between 0.8 and 0.9, preferably equal to 0.85.

The ratio d2/W22 is in the range between 0.85 and 0.95, and preferably equal to about 0.9.

With these values, the diameter D1 can be made strictly smaller than the diameter D30, which is well suited for the case of relatively thick denim yarns.

This ratio D1/D30 is adapted to the thickness of the yarn to be clamped and ranges between 0, 98 and 1.

The portion 30a starts from the edge of the opening O22 on the side of the main plane P22 opposite to the rubber profile 34. The value of angle a helps to center portion 30a about inner surface 36 relative to axis X22. In particular, said portion 30a extends angularly around said longitudinal axis X22 and over a first angular sector having an apex angle β, up to a transition step 33. The value of the angle β is between 30 ° and 50 °, preferably equal to 40 °. The side flat surfaces of the rubber profile 34 forming the inner surface 36 extend angularly Γ around the longitudinal axis X22 and over a second angular sector having a top angle. The value of the angle Γ is between 30 ° and 65 °, preferably equal to 55 °. Said second angular sector being opposite to said first angular sector of said portion 30a with respect to said rotation axis X20. In other words, the inner surface 36 faces the portion 30a with the axis X22 therebetween. The transition step 33 is opposite the opening O22 relative to the plane formed by the axis Z22 and the longitudinal axis x 22. In other words, the portion 30a extends from the edge of the opening O22 along the transverse axis y22 to beyond the longitudinal axis X22. Thus, when the clamping lever 24 is in the clamping position, it engages the portion 30a in two opposite transverse directions parallel to the transverse axis y 22. This accurately positions the clamp bar 24 in the clamp volume V22 along the transverse axis y 22.

The portion 30b begins at an edge of the opening O22 that is on the same side of the major plane P22 as the inner surface 36, and the portion 30b extends to the inner surface 36.

In the clamping position shown at the bottom of fig. 13, the clamping lever 24 partially protrudes out of the clamping volume v 22. In particular, the clamping bar 24 projects partially outside the clamping rail 22 and over two portions of the front surface 23, located respectively on either side of the main plane P22, by a non-zero distance d 5. In other words, the clamping lever 24 partially protrudes through the opening O22 and out of the clamping rail 22. This is due in particular to the geometry of the clamping lever 24 and the clamping rail 22. The force exerted by the warp threads 200 and the rubber profiles 34 on the clamping bar 24 in a direction parallel to the axis Y22 is directed to the right in fig. 13. The reaction force exerted by the

portions

30a and 30b of the inner cylindrical surface 30 of the track 22 on the circular surface 48 of the clamping bar is directed to the left in fig. 13 and is defined by the geometry of the

surfaces

30 and 48.

In practice, the quantitative d5/d2 is chosen between 0.1 and 0.2, preferably equal to about 0.15.

The yarn framework 12 of this fourth embodiment is shown in fig. 14. In the drawing of the machine 2 incorporating this yarn framework 12, the warp yarns 200 are drawn from the warp beam first on the side of the lower side member 16B and then on the side of the upper side member 16B. In an embodiment not shown, the lower yarn gripping device 20B2 is removable, as considered above, in place of the first embodiment.

As in the first embodiment, the two longitudinal grooves 184 of the track 22 have the same geometry and are offset by a non-zero distance d6 along the axis Y22. In this example, the value of d6 may be chosen between 1 and 5 mm, preferably equal to 2 mm. Thus, when two yarn clamping devices are stacked and cooperate with the common guide projection 180, as in the yarn clamping devices 20a1 and 20a2 of fig. 15, their tracks 22 are offset by a distance d 6. This means that the yarn layers L1 and L2 are also offset by the same distance d6, as shown in fig. 8, where the drawing-through unit 8 is represented by its envelope. This distance d6 facilitates identification and handling of layers L1 and L2 in the drawing-through machine 2.

Since the grooves 184 are also offset in the first embodiment, as can be derived from fig. 7 and 8, the layers L1 and L2 are also offset in this embodiment.

The two yarn clamping devices 20 can slide in a direction parallel to the respective axis of rotation X20 and longitudinal axis X22, i.e. as in the first embodiment the lower yarn clamping device 20B2 and the upper yarn clamping device 20a 2. The displacement of the thread clamping devices 20a2 and 20B2 is controlled by an adjusting device 160. The adjusting device associated with the lower slidable yarn clamping device 20B2 is separate from the rest of the yarn frame 12 and is shown on a larger scale in fig. 14. Each adjustment device 160 includes a hand wheel 168 that drives a parallel gear 166, and a nut 162 is mounted on the output shaft of the parallel gear 166, as in the first embodiment. A housing 171 is provided on the nut 162 for connecting the nut to a not shown projection, for example a pin, of the respective clamping rail 22. The housing 171 achieves a function similar to that of the bolt 170 of the first embodiment.

During the drawing-in process, the drawing-in unit 8 is moved parallel to the longitudinal axis X22 of the clamping rail 22. To assist this movement, the threading unit 8 is equipped with a top guide roller 81 and a bottom guide roller 83. The top guide roller 81 is mounted and fixed on the drawing-through unit 8 and freely rotatable about an axis of rotation Z81, while the bottom guide roller 83 is also mounted and fixed on the drawing-through unit and freely rotatable about another axis of rotation Z83. Advantageously, the axes Z81 and Z83 are parallel to each other and to the yarns 200 in the yarn layers L1 and L2. During threading, each

roller

81 or 83 comes into contact with a portion of the circular surface 48 of the clamping bar 24 and rolls against a portion of the circular surface 48 of this clamping bar 24, which clamping bar 24 projects partly into the clamping track 22 of the yarn clamping device 20 belonging to the second pair of yarn clamping devices 20a2, 20B 2. This allows it to guide the longitudinal movement of the threading unit 8 along the longitudinal axis X22 of each clamping rail 22 and to position the threading unit with respect to yarn layers L1 and L2, as shown in fig. 15.

In a variant of the invention, which is not shown, only one

roller

81 or 83 is provided for guiding the threading unit in a direction parallel to the longitudinal axis X22 of the clamping rail 22.

In a fifth embodiment shown in fig. 16, the inner surface 36 of the rubber profile is curved, in particular concave. The bottom of the recess 32 is also curved, in particular concave, having generally the same cross-section as the inner surface 36.

Advantageously, said inner surface 36 has a cross section in the form of a circular arc with a diameter slightly smaller than the diameter of the adjacent portion 30b of said inner surface 30. The inner surface 36 projects at least partially into a cylindrical volume having a diameter equal to the maximum dimension of the clamping lever, i.e. equal to the diameter D1, and which is defined in the clamping volume V22 about the axis of rotation X24 of the clamping lever 24.

The portion 30b of the inner surface 30 forms, together with the other portion 30a of the surface 30, a holding area for blocking the clamping bar 24 within the clamping volume V22 in the clamping position of the clamping bar 24. The intermediate surface 30 between the intermediate position and the clamping position also forms a holding zone for blocking the clamping lever 24 within the clamping volume V22 when the clamping lever 24 is rotated in the clamping direction r 2.

In this case, the inclination angle α of the inner surface 36 is an average inclination angle. Its value is between 10 ° and 30 °, preferably equal to about 16 °.

In this case, the angle of rotation between the insertion position and the intermediate position is preferably equal to 45 ° in the clamping direction R2, and the angle of rotation between the intermediate position and the clamping position is preferably equal to 40 ° in the clamping direction R2.

In the clamping position shown at the bottom of fig. 16, the portion of the clamping lever 24 that penetrates the inner surface 36 is a portion of the circular surface 48, rather than the edge 49 as described in the previous embodiments. In this clamping position, the clamping bar 24 partially protrudes through the opening 22 out of the clamping rail 22. In particular, as in the fourth embodiment, the clamping bar 24 partially protrudes beyond the clamping volume V22 and beyond the two portions of the front surface 23 located on either side of the main plane P22, in particular beyond the non-zero distance d 5.

As in the previous embodiment, in the intermediate and clamping positions shown in the middle and at the bottom of fig. 16, and between the intermediate and clamping positions, when the clamping bar 24 is rotated in the clamping direction R2, the ratio d24/W22 is strictly greater than 1, and the holding zone of the clamping bar 24 is formed by the

portions

30a and 30b of the inner cylindrical surface 30 for blocking the clamping bar 24 within the clamping volume v 22. The dimension d24 and the width W22 are measured at the same longitudinal level along the axis of rotation x 20.

In the sixth embodiment of fig. 17, the clamping lever 24 is hollow as in the second embodiment. The external cross section of the clamping bar 24 defines a circular surface 48 made up of two

portions

48a and 48b centred on the longitudinal axis X24 and of two parallel and

opposite planes

50a and 50 b. At least when it is in the clamping position shown in fig. 17, and with its maximum outer dimension d24 of the cross-section strictly greater than the width W22 of the clamping volume opening O22, these dimensions and widths being measured on the same longitudinal level along the axis of rotation x20, the two

portions

30a and 30b of the inner surface 30 of the clamping rail together form a holding zone for blocking the clamping bar 24 within the clamping volume V22. The holding area of the clamping rail 22 is formed by two

cylindrical sections

30a and 30 b. In the clamping position of the clamping lever 24, the rounded surface 48 and the

portions

30a, 30b cooperate in a form-fitting manner with the yarn of the middle 200.

In the seventh embodiment of fig. 18, the portion 30b of the inner surface 30 is cylindrical, with a cross section in the form of an arc of a circle centred on the axis x 24. The portion 30a does not have a cross section in the form of a circular arc. Portion 30a includes a plurality of surfaces 30a1, 30a2, and 30a 3. The surface 30a1 is convex to form a transition between the edge of the opening O22 and the surface 30a2 perpendicular to the axis Y22 and parallel to the axes X22 and Z22. The surface 30a3 is a plane perpendicular to the axis Z22 and parallel to the axes X22 and y 22. The surface 30a1 rotates at least partially along the lateral axis y22 toward the bottom of the clamping volume V22 at the opposite of the opening O22. In the clamped position shown in fig. 18, the surfaces 30a1 and 30a3 engage the clamping bar 24 with the yarn in the middle. As in the other embodiments, portion 30a also defines, with portion 30b, a retention area for blocking clamping bar 24 within clamping volume V22 in the bar's clamped position. In particular, the surface 30a1 cooperates with the rounded surface 48 of the clamping bar 24 along the transverse direction Y22 with the yarn 200 in between. In this clamping position, the portion 30b and the circular surface 48 fit together in a form-fitting manner, with the yarn 200 in the middle. In this position, the ratio d24/W22 is strictly greater than 1, and the dimension d24 and the width W22 are the same as in the first embodiment. The dimension d24 and the width W22 are measured at the same longitudinal level along the rotation axis x 20.

In this embodiment, the clamping rail 22 is formed of two

parts

22a and 22b secured together, for example by screws or welding. The two parts cannot move relative to each other. For all other embodiments, the

portions

30a and 30b cannot move relatively with respect to the recess 32 that receives the rubber profile 34 in the clamping rail 22.

In the drawing machine 2 and the binding device 3 of fig. 1 to 3 and 19, the yarn clamping device 20 of the second to seventh embodiments may be used instead of the yarn clamping device of the first embodiment.

In all these embodiments, the inner surface 36 of the single rubber profile is located on one side of the main plane P22 and partially defines the clamping volume V22, while the clamping rail completely defines this clamping volume V22 on the other side of the main plane P22. In all these embodiments, the inner surface 36 should be considered as the surface portion of the rubber profile 34 through which the clamping bar 24 passes during clamping. Any additional rubber profile located in the clamping volume V22 and any additional surface of the rubber profile 34, which all define the clamping volume, but do not cooperate with the clamping bar 24 during clamping and in the clamping position, do not form an inner surface but, within the meaning of the invention, form part of the clamping track.

In an alternative embodiment not shown, in the clamped position, the maximum outer dimension D24 of the clamping bar cross-section, measured parallel to the axis Z22, is not equal to the diameter D1 of the clamping bar 24, and the plane 50 is not parallel to the axis Z22.

In an alternative embodiment not shown, in the clamping position, the retaining zone extends only on a single side of the main plane P22, preferably on the side of the main plane P22 opposite to the inner surface 36.

The angles of 40 °, 45 °, 50 ° and 90 ° mentioned above may be different. A first angle of the rotational amplitude of the clamping lever 24 between the insertion position and the intermediate position in the clamping direction R2 may be between 30 ° and 55 °, depending on the position of the inner surface 36 within the clamping volume v 22. A second angle of the rotational extent of the clamping lever 24 between the insertion position and the clamping position in the clamping direction R2 can be between 80 ° and 100 °.

In another alternative embodiment, the yarn clamping device 20 comprises a single holding device 26 mounted at a first end of its clamping rail 22 for cooperating with an intermediate portion 46 near the first end of the clamping bar 24. A rod retainer is located at the second end of the clamping rail for retaining the second end of the clamping rod opposite the intermediate portion relative to the clamping rail. In this case, the second end of the clamping bar is first inserted into the bar holder, and then the clamping bar is tilted such that its central portion enters the clamping volume and its middle portion enters the housing of the holding device. During the insertion of the clamping bar, the bar does not have a purely translatory movement and it is inclined with respect to the longitudinal axis of the clamping rail.

In another variant, the body 60 is provided with an indexing pin projecting in the housing H26 and configured to engage in a circumferentially limited recess provided on the outer cylindrical surface 120 of the retaining member 76. This is to allow the retaining member 76 to move only within a limited angular range between the release position and the third position which is reached when the clamping lever is rotated in the clamping direction between its insertion position and its clamping position. In this case, it is impossible for the holding member 76 to make a 360 ° rotation. Furthermore, in this case, the insertion of the clamping bar 24 is not possible in the insertion position in which the flat surface 50 of the clamping bar 24 does not face the inner surface 36.

In another variant, the direction of translation a90 of the slidable obstacle-forming part 90 is not parallel to the axis Z20, but is, for example, inclined with respect to the axes Z60 and y 60.

In another embodiment, the spring 92 is omitted. In this case, the obstacle may be weighted such that it can move from its retracted position to its blocking position and remain in the blocking position due to gravity. In this alternative embodiment of the holding device, the holding device may only comprise obstacles if it is manufactured directly in the clamping rail 22 as described in the third embodiment.

In all embodiments, in the intermediate position and the clamping position of the clamping lever 24, and when the clamping lever 24 is rotated in the clamping direction R2 between the intermediate position and the clamping position, the clamping lever 24 cooperates with the inner surface 30 in the transverse direction Y22, abutting against the inner surface 30 in the transverse direction Y22 opposite to the translational movement a1, with the yarn 200 in the middle thereof. Thus, the clamping rail 22 forms a holding area for blocking the clamping bar 24 within the clamping volume V22, so that at least in the clamping position the clamping bar 24 cannot be completely withdrawn from the clamping volume V22 through the opening O22, but only has a lateral movement opposite to the translational movement a 1. This engagement between the clamping lever 24 and the inner surface 30 does not prevent the clamping lever 24 from rotating about the axis of rotation X20 within the clamping volume V22 if the clamping lever 24 is rotated by an operator. In the clamping position, the holding zone blocks the clamping lever 24 in a position within the clamping volume V22 in which the clamping lever 24 protrudes or does not protrude through the opening O22 as described in the fourth, the illustrated and the seventh embodiments.

In all embodiments, due to the inner surface 36 facing the opening O22, the rubber profile 34 generates a resilient force on the clamping bar 24 along the transverse axis Y22 towards the opening O22 when the clamping bar 24 passes through the inner surface 36. Since the inner surface 36 is inclined at an angle α of between 10 ° and 30 ° with respect to the main plane P22, the rubber profile 34 also generates, on the clamping bar 24, when the clamping bar 24 penetrates the inner surface 36, a spring force in the direction of the inner surface of the clamping rail 22 along the axis Z22, which spring force defines a clamping volume V22 on the side of the main plane P22 opposite the inner surface 36.

The embodiments and examples listed above may be combined to create new embodiments of the invention within the scope of the appended claims.

Claims

1. A yarn clamping device (20) for clamping yarns (200) of a yarn layer (L1, L2), the device comprising

A clamping rail (22) defining a clamping volume (V22) extending along a longitudinal axis (X22),

a clamping bar (24) configured to be inserted into the clamping volume through an insertion/extraction opening (O22) of the clamping rail and in a direction (Y22) transverse to the longitudinal axis, a longitudinal portion (42) of the clamping bar accommodated in the clamping volume having a non-circular cross section, said clamping bar (24) having a clamping rotational movement in a clamping direction (R2) relative to the clamping rail (22), within the clamping volume and about an axis of rotation (X20) parallel to the longitudinal axis of the clamping rail,

starting from the insertion position, in which the first external dimension (d2) of the clamping bar cross-section is parallel to and less than the width (W22) of the insertion/extraction opening (O22), this allows the bar (24) to pass through the insertion/extraction opening (O22),

to a clamping position in which the clamping bar clamps the yarn located in the clamping volume against an inner surface (36) located inside the clamping track,

it is characterized in that

With respect to a main plane (P22) of the clamping volume (V22), which contains the rotation axis (X20) and passes through the insertion/extraction opening (O22) in the middle of the opening, one side of the clamping volume (V22) is defined by the clamping rail (22) and the other side of the clamping volume is defined in part by an inner surface (36) belonging to a rubber profile (34) housed in the clamping rail (22);

when the clamping bar (24) is in the clamping position, the clamping bar passes through the inner surface (36) of the rubber profile (34) with the yarn (200) in between; and

when the clamping bar is in the clamping position, the maximum outer dimension (D24, D1) of the clamping bar cross-section is parallel to the width (W22) of the insertion/extraction opening (O22) and strictly greater than the width of this insertion/extraction opening, the maximum outer dimension (D24, D1) of the clamping bar cross-section and the width (W22) of the insertion/extraction opening being measured on the same longitudinal level along the axis of rotation (X20).

2. Yarn clamping device as in claim 1, characterised in that the inner surface (30) of the clamping rail (22) at the level of the insertion/extraction opening (O22) partially delimits the clamping volume (V22) when the clamping lever (24) is in the clamping position, forming a holding zone which cooperates with the clamping lever in the transverse direction (Y22), with the yarn (200) in between, for blocking the clamping lever in the clamping volume.

3. Yarn clamping device according to claim 2, characterised in that the retaining area extends on both sides of the main plane (P22).

4. Yarn clamping device according to claim 2, characterised in that the holding region of the clamping rail (22) is formed by at least one section (30b) of the inner surface (30), which section (30b) is cylindrical, centred on the axis of rotation (X20), and wherein the cylindrical section (30b) cooperates in a form-fitting manner with the clamping lever (24) in the clamping position of the clamping lever (24).

5. Yarn clamping device as in claim 1, characterised in that the inner surface (36) of the rubber profile (34) is facing the insertion/extraction opening (O22) with an inclination angle (a) between 10 ° and 30 ° with respect to the main plane (P22).

6. Yarn clamping device as in claim 5, characterised in that the angle of inclination (α) is equal to 16 ° or 20 °.

7. Yarn clamping device according to one of the claims 1 to 6, wherein the clamping lever partially protrudes through the insertion/extraction opening (O22) and out of the clamping rail (22) when the clamping lever (24) is in the clamping position.

8. Yarn clamping device according to one of the claims 1 to 6, wherein, when the clamping lever reaches an intermediate position relative to the clamping rail (22) in the clamping movement in the clamping direction (R2) and moves relative to the insertion position,

-the clamping bar has a clearance (C22) with respect to the inner surface (36) of the rubber profile (34),

-the yarn (200) in the clamping volume (V22) is movable between the clamping bar (24) and the inner surface (36) inside the clamping rail (22), and

-the external dimension (d24) of the cross section of the clamping bar is parallel to the width (W22) of the insertion/extraction opening (O22), which is strictly greater than this width on the same longitudinal level.

9. Yarn clamping device as in claim 8, characterized in that the non-circular cross section of the clamping bar (24) comprises at least a circular surface (48) and a plane surface (50; 50b), wherein in the intermediate position the plane surface (50; 50b) faces the inner surface (36) of the rubber profile, wherein in the clamping position the plane surface (50; 50b) faces the bottom of the clamping volume (V22) in the transverse direction (Y22) in the opposite direction of the insertion/extraction opening (O22), and wherein the inner surface (30) of the clamping rail (22) partly delimits the clamping space (V22) and cooperates with the circular surface (48) to guide the rotational movement (R2) of the clamping bar in the clamping space (V22) between the intermediate position and the clamping position.

10. Yarn clamping device according to claim 8,

the yarn clamping device further comprises at least one holding device (26) comprising an obstacle (90);

said obstacle is configured to have a movement relative to said clamping lever from a retracted position to a blocking position during said clamping rotational movement of said clamping lever, said retracted position of said obstacle corresponding at least to said insertion position of said clamping lever and the blocking position of the obstacle corresponding at least to an intermediate position relative to a clamping rail (22),

when the obstruction is in its retracted position, the obstruction does not prevent rotational movement of the clamping lever (24) within the clamping volume between the insertion position and the clamping position,

when the obstacle is in its blocking position and the clamping lever is in the intermediate position, the obstacle

Does not prevent the clamping rod from rotating in the clamping direction (R2) in the clamping volume (V22) to the clamping position thereof, and

preventing a rotational movement of the clamping rod in a direction (R3) opposite to the clamping direction within the clamping volume, and

the retaining device (26) further comprises a resilient member (92) urging the barrier towards its blocking position.

11. Yarn clamping device according to claim 10, characterised in that the obstacle (90) is at least partially accommodated in a housing (86; 194) of the yarn clamping device (20) with the possibility of sliding between a retracted position and a blocking position along a direction (A90) transverse to the axis of rotation (X20) and the transverse direction (Y22), wherein the holding device (26) further comprises a holding member (76) which is rotationally connected with the clamping lever (24) about the axis of rotation (X20) between the insertion position and the intermediate position, wherein in the insertion position the holding member (76) does not prevent a movement (A1) of the clamping lever (24) through the insertion/removal opening (O22), and wherein in the intermediate position of the clamping lever the holding member abuts against the obstacle (90) in a circumferential direction about the axis of rotation (X20), to prevent a rotational movement (R3) of the clamping lever within the clamping volume (V22) in a direction opposite to the clamping direction.

12. Yarn frame (12) comprising at least one pair of yarn clamping devices (20) spaced apart in the direction of yarn extension, characterized in that at least one of the yarn clamping devices (20) is in accordance with any one of the preceding claims.

13. Yarn frame as in claim 12, characterised in that the yarn frame (12) is configured for clamping yarns of two yarn layers (L1, L2), wherein the yarn frame comprises

A first pair of yarn clamping devices (20A1, 20B1) spaced apart in the direction of yarn extension within the first layer (L1) for clamping the yarns of the first layer (L1),

a second pair of yarn clamping devices (20A2, 20B2) spaced apart in the direction of yarn extension within the second layer (L2) for clamping the yarns of the second layer (L2)

Wherein

The thread clamping device (20) of the invention belongs to a pair of thread clamping devices and is supported on a longitudinal beam of a thread frame (12) along a longitudinal axis (X22) of a clamping volume thereof and has the possibility of translation (A3), the thread clamping device of another pair of thread clamping devices, and/or

The thread clamping device (20) of the invention belongs to a pair of thread clamping devices, and in their clamping configuration, the thread of the first layer (L1) is interposed between a longitudinal beam of the thread frame and a thread clamping device of a second pair of thread clamping devices (20A2, 20B2) which are at least partially detachably mounted on the thread frame.

14. Yarn frame as in claim 11, characterised in that the inner surface (36) of the rubber profiles (34) of the yarn clamping device (20) according to the invention is located in the clamping volume (V22) on the same side of the main plane (P22) of the clamping volume (V22) as the other yarn clamping device of the same pair of yarn clamping devices.

15. A drawing-in machine (2) for drawing-in warp threads (200), comprising a drawing-in unit (8) and at least one thread frame (12) according to any one of claims 12, 13 and 14.

16. The drawing-in machine according to claim 14,

when the clamping lever (24) is in the clamping position, the clamping lever partially protrudes through the insertion/extraction opening (O22) and protrudes from the clamping rail (22),

the drawing-in unit (8) can move along the longitudinal axis (X22) of the clamping rail (22) relative to the yarn frame (12),

at least one roller (81,83) fixed longitudinally on the drawing-in unit (8) is in contact with a clamping bar (24) projecting from the clamping rail for guiding a relative movement between the drawing-in unit and the yarn frame (12) along the longitudinal axis of the clamping rail.