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

Abstract

A yarn clamping device (20) comprises a clamping rail (22), a clamping rod (24), the clamping rod (24) being configured to be inserted into a clamping volume, the clamping rod (24) being capable of a clamping rotational movement relative to the clamping rail (22) in a clamping direction (R2), from an insertion position to a clamping position. The yarn clamping device further comprises at least one retaining device (26), the retaining device comprising an obstacle (90), which is capable of a movement relative to the clamping rod from a retracted position to a blocking position during the clamping rotational movement of the clamping rod. The retracted position of the obstacle corresponds at least to the insertion position of the clamping rod, while the blocking position of the obstacle corresponds at least to an intermediate position relative to the clamping rail (22), the intermediate position being reached by the clamping rod during its clamping rotational movement and being offset relative to the insertion position. When the obstacle (90) is in its retracted position, it does not block the rotational movement of the clamping rod within the clamping volume between the insertion position and the clamping position. When the obstacle is in its blocking position and when the clamping rod is in the intermediate position, the obstacle does not prevent the clamping rod from rotating in the clamping volume in a clamping direction (R2) towards its clamping position, but the obstacle prevents the clamping rod from rotating in the clamping volume in a direction (R3) opposite to the clamping direction.

Description

Technical Field

[0001] The present invention relates to a yarn clamping device for clamping a yarn layer. The present invention also relates to a yarn frame and a warp drawing-in machine comprising such a yarn clamping device. Finally, the present invention relates to a method for clamping yarns of a yarn layer using such a yarn clamping device. Background Art

[0002] In the weaving field, it is known to use yarn clamping devices to clamp the different yarns of a warp layer, in particular during the warp preparation process. This process requires clamping the yarns of a yarn layer, for example, to tie two warp yarn layers together or to thread the warp yarns of a yarn layer into a bundle on a warp loom.

[0003] In this context, US-A-5 381 594 discloses a machine for automatically drawing in warp yarns, wherein two pairs of yarn clamping devices are mounted on a single yarn frame which is movable longitudinally relative to the drawing-in 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 clamping device comprises a comb introduced into a clamping housing, which is defined between a fixed wall and a movable wall, the movement of which may lead to a jamming of the comb with the clamping rail and a blockage of some yarns between the comb and the clamping rail. Therefore, even if it is satisfactory worldwide, 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 rotating clamping rod which is inserted into the clamping rail of the yarn clamping device so as to block the yarn within the rail. In the inserted position of the elastic tube, the yarn is between the tube and the clamping rail. The tube has already deformed against the clamping rail, exerting a primary clamping effect on the yarn, which is not easily distributed or tensioned in this position. Furthermore, unless they are in the clamping position, the tube and rod may pop out of the clamping rail due to the high tension in the yarn. In this case, the yarn clamping process should be restarted from the beginning.

[0004] On the other hand, EP-A-2 662 481 discloses a yarn frame having two spaced-apart clamping rails, each equipped with two rubber profiles and adapted to receive clamping rods. During tensioning of the yarn layer, the yarn is first clamped in one of the clamping rails and then tensioned before the deflection rod is introduced into the other clamping rail. This approach can result in a 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 rails can be ejected from these rails due to the reaction force exerted by the yarn, which can also lead to irregular yarn distribution. Summary of the Invention

[0005] The object of the present invention is to solve these problems by providing an optimized yarn clamping device which allows to effectively clamp the yarn during the yarn clamping process without the risk of the clamping rod popping out.

[0006] In this respect, the invention relates to a yarn clamping device for clamping a yarn layer, the device comprising

[0007] - a clamping rail which defines a clamping volume extending along the longitudinal axis,

[0008] a clamping rod, which is configured to be inserted into the clamping volume through an insertion / removal opening of the clamping rail and in a direction transverse to the longitudinal axis, the 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 the clamping space in a clamping direction and about a rotational axis parallel to the longitudinal axis of the clamping rail,

[0009] o starting from an insertion position in which the rod can pass through the insertion / removal opening and a first outer dimension of the clamping rod cross section parallel to the width of the insertion / removal opening is smaller than this width,

[0010] o To a clamping position in which the clamping lever clamps the yarn located in the clamping volume against an inner surface located inside the clamping track.

[0011] According to the present invention, the yarn clamping device further comprises at least one retaining device, which comprises an obstacle. The obstacle is configured to move 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 inserted position of the clamping lever, and the blocking position of the obstacle corresponding at least to an intermediate position relative to the clamping track, which position is reached by the clamping lever during its clamping rotational movement and is offset relative to the inserted position, and wherein

[0012] o The yarn in the clamping volume can move between the clamping rod and the inner surface located inside the clamping track, and

[0013] o A second outer dimension of the clamping rod cross section is parallel to the width of the insertion / removal opening and is strictly greater than this width at the same longitudinal level.

[0014] Furthermore, when the barrier is in its retracted position, the barrier does not prevent the rotational movement of the clamping rod within the clamping volume between the inserted position and the clamping position.

[0015] ○ The rotational movement of the clamping lever in the clamping direction towards its clamping position within the clamping volume is not prevented, but

[0016] o A rotational movement of the clamping lever within the clamping volume in a direction opposite to the clamping direction is prevented.

[0017] Thanks to the invention, the retaining device with the obstruction prevents the clamping lever from moving in the clamping rail from its intermediate position to its inserted position in the direction opposite to the clamping direction. This makes it possible to distribute the yarn in the clamping volume when the clamping lever is in the intermediate position, without any risk of the clamping lever being ejected from the clamping rail when a pulling force (extraction effort) due to the yarn present in the clamping volume is exerted on the clamping lever.

[0018] According to a further advantageous aspect of the present invention, the yarn clamping device of the present invention may be combined with one or more of the following features in any technically compatible configuration:

[0019] - The retaining device also comprises an elastic member which pushes the obstacle towards its blocking position.

[0020] The obstacle is at least partially accommodated in a housing of the yarn clamping device and is slidably movable between the retracted position and the blocking position in a direction transverse to the rotation axis and in a transverse direction.

[0021] The barrier is movable from its blocking position into its retracted position for all positions relative to the clamping rail reached by the clamping lever during the rotational movement in the clamping direction between the intermediate position and the clamping position.

[0022] - In the inserted position and for all positions reached by the clamping lever during its rotational movement between the inserted position and an intermediate position in the clamping direction, the obstacle is held in the retracted position by a part of the clamping lever or of the yarn clamping device which is rotationally connected to the clamping lever about the rotation axis.

[0023] The clamping lever or a part of the yarn clamping device which is rotatably connected to the clamping lever about the rotation axis is configured to move the obstacle from its blocking position into its retracted position when the clamping lever is rotated from its clamping position into its inserted position within the clamping volume.

[0024] - the yarn clamping device comprises two retaining devices, one at each longitudinal end of the clamping rail, each retaining device comprising a body accommodating an obstacle, each body being fixed by the clamping rail, and wherein the clamping lever comprises at least

[0025] - a first central longitudinal portion housed in the clamping housing for selectively clamping the yarn on an inner surface located inside the clamping track, and

[0026] - two second longitudinal portions, each situated longitudinally to the first central longitudinal portion, housed in the body of the retaining device and adapted to cooperate with an obstacle.

[0027] - The holding device further comprises a holding member which is connected in rotation with the clamping rod about the axis of rotation between an insertion position and an intermediate position, wherein, in the insertion position, however, the holding member does not prevent a movement of the clamping rod through the insertion / removal opening, and in the intermediate position of the clamping rod, the holding member abuts against an obstacle in a circumferential direction about the axis of rotation to prevent a rotational movement of the clamping rod within the clamping volume in a direction opposite to the clamping direction.

[0028] - the retaining member has an outer cylindrical surface centered on the rotation axis and a recess, the recess being configured to receive the clamping rod when the clamping rod is received in the clamping volume and being defined by at least one branch having a plane parallel to the rotation axis, while the obstacle is suitable for cooperating with the outer cylindrical surface of the retaining member in the retracted position, wherein the 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.

[0029] In the blocking position of the obstacle, at its longitudinal height, the retaining member limits the width of the passage opening for the clamping rod from the recess to be strictly smaller than a dimension of the clamping rod parallel to the width of the passage opening.

[0030] In an intermediate position of the clamping lever, a surface of the clamping lever abuts against the obstacle in a circumferential direction about the rotation axis, preventing a rotational movement of the clamping lever within the clamping volume in a direction opposite to the clamping direction.

[0031] - The configuration of the yarn clamping device is as described above, and

[0032] - with respect to a main plane of the clamping volume containing the axis of rotation and passing through the insertion / extraction opening in the middle of this opening, the clamping volume is delimited on one side by the clamping track, wherein the clamping volume is delimited on the other side by the inner surface of the rubber profile housed in the clamping track,

[0033] - when the clamping lever is in the middle position, the clamping lever has clearance relative to the inner surface of the rubber profile, and

[0034] When the clamping rod is in the clamping position, the clamping rod penetrates the inner surfaces of the rubber profile, the yarns being between said inner surfaces.

[0035] According to a second aspect, the present invention relates to a yarn frame comprising at least two yarn clamping devices spaced apart in a yarn extending direction, and at least one of the yarn clamping devices is as described above.

[0036] Advantageously, the yarn frame is configured for clamping the yarns of two yarn layers, wherein the yarn frame comprises

[0037] - a first pair of yarn clamping devices spaced apart in the yarn extending direction within the first layer, for clamping the yarns of the first layer.

[0038] - a second pair of yarn clamping devices spaced apart in the yarn extending direction within the second layer for clamping the yarns of the second layer

[0039] in

[0040] - the yarn clamping device of the invention belongs to a pair of yarn clamping devices and is supported on the longitudinal beam of the yarn frame and can be translated along the longitudinal axis of its clamping volume relative to the yarn clamping device of the other pair of yarn clamping devices, and / or

[0041] - The yarn clamping device of the present invention belongs to a pair of yarn clamping devices, and in their clamping configuration, the yarns of the first layer are interposed between the longitudinal beams of the yarn frame and the yarn clamping devices of the second pair of yarn clamping devices, which are at least partially detachably mounted on the yarn frame.

[0042] According to another advantageous aspect of the invention, the yarn clamping device is as defined above and the inner surface of the rubber profile is located on the same side of the main plane as the other yarn clamping device of the same pair within the clamping volume.

[0043] In a third aspect, the present invention relates to a drawing-in machine for drawing warp threads through a webbing, the drawing-in machine comprising at least one yarn frame as described above.

[0044] Finally, according to a fourth aspect, the invention relates to a method for clamping a yarn of a yarn layer in a yarn clamping device, the method comprising

[0045] - a clamping rail which defines a clamping volume extending along the longitudinal axis,

[0046] a clamping rod, which is configured to be inserted into the clamping volume through an insertion / removal opening of the clamping rail and in a direction transverse to the longitudinal axis, the longitudinal portion of the clamping rod housed 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 the clamping volume and about an axis of rotation parallel to the longitudinal axis of the clamping rail

[0047] From the inserted position, the rod can pass through the insertion / removal opening,

[0048] o To a clamping position in which the clamping lever clamps the yarn located in the clamping volume against an inner surface located inside the clamping track.

[0049] The method of the present invention utilizes an obstacle movable relative to the clamping rod.

[0050] a retracted position corresponds at least to the inserted position of the clamping lever, and wherein the retracted position does not prevent a rotational movement of the clamping lever about the rotation axis,

[0051] - The blocking position of the obstacle

[0052] o The clamping lever is not prevented from rotating in the clamping direction towards its clamping position within the clamping volume, and

[0053] o The clamping lever is prevented from performing a rotational movement in the clamping volume in a direction opposite to the clamping direction from an intermediate position relative to the clamping guide rail reached by the clamping lever during its clamping rotational movement, and wherein:

[0054] ■ The yarn in the clamping volume can move between the clamping rod and the inner surface located inside the clamping track, and

[0055] ■The clamping rod cannot be moved out of the clamping volume in the lateral direction.

[0056] The method comprises at least the following steps:

[0057] a) introducing the yarn and the clamping rod into the clamping volume while the barrier is in its retracted position;

[0058] b) moving the clamping rod within the clamping volume to its middle position;

[0059] c) moving the barrier from its retracted position to its blocking position;

[0060] d) adjusting the position of the yarn within the clamping volume; and

[0061] e) Move the clamping lever in the clamping direction until it reaches the clamping position.

[0062] When the barrier is in its blocking position, steps d) and e) are performed. During step b), the movement of the clamping lever relative to the clamping rail automatically causes the movement of the barrier from its retracted position to its blocking position. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The invention will be better understood on the basis of the following description, which is given as a non-limiting example and is made with reference to the following drawings:

[0064] - Figure 1 is a perspective view of the warp drawing-in machine according to the present invention;

[0065] - Figure 2 This is an enlarged partially exploded perspective view of the yarn frame of the present invention, which belongs to Figure 1 drawing-in machine;

[0066] - Figure 3 yes Figure 2 A front view of a clamping device of a yarn frame, the clamping device being the present invention;

[0067] - Figure 4 It is along Figure 3 A sectional view along the line iv-iv in FIG, showing three positions of the clamping lever relative to the clamping rail at the level of the clamping volume;

[0068] - Figure 5 It is along Figure 3 Sectional view along line vv in FIG. 1 , showing the same three positions of the clamping lever at the level of the holding device;

[0069] - Figure 6 yes Figure 5 A perspective exploded view of a retaining device;

[0070] - Figure 7 It is along Figure 2 A sectional view of plane VII in FIG.

[0071] - Figure 8 yes Figure 7 Enlarged view of box VIII;

[0072] - Figure 9 is with Figure 2 A perspective view equivalent to Box IX in FIG. 1 , with a single yarn layer and a yarn clamping device partially disassembled from the yarn frame;

[0073] - Figure 10 yes Figure 9 An enlarged view of the box X in FIG;

[0074] - Figure 11 The clamping device of the second embodiment of the present invention is Figure 5Quite a view;

[0075] - Figure 12 The clamping device of the third embodiment of the present invention is similar to Figure 5 Views; and

[0076] - Figure 13 It is a partial perspective view of a bundling device according to the present invention that combines a number of yarn clamping devices and a yarn frame. DETAILED DESCRIPTION

[0077] Figure 1 The drawing-in machine 2 shown comprises a movable trolley 6 and a fixed structure 4 supporting a drawing-in unit 8, which may be of any known type and is indicated by its external shape.

[0078] The drawing-in machine 2 is designed to hold the warp yarns of the first and second layers L1, L2 in position so that the warp yarns of these layers can be inserted by the drawing-in unit 8 into the wire harness part (not shown) of the loom. Some of these are mounted on a support member 10 carried by a trolley 6. The wire harness itself is known and may include heddles, springs and sometimes also wires.

[0079] 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 called “draw-in frame”), which comprises three columns 14, some cross beams 15 and two beams 16, which together form the main structure of the frame 12.

[0080] The yarn frame 12 is mounted on the fixed structure 4 and can be tilted relative to this main structure about an axis parallel to the longitudinal direction of the beam 16 .

[0081] Each beam 16 carries two yarn clamping devices 20 arranged in pairs, each of which is provided to hold the yarns of yarn layer L1 and yarn layer L2 relative to the yarn frame 12. More precisely, the first yarn clamping device 20 of each pair of yarn clamping devices is mounted on the upper beam 16A, while the second yarn clamping device of the same pair of yarn clamping devices is mounted on the lower beam 16B. Thus, the yarn frame 12 includes a total of four yarn clamping devices 20.

[0082] If you can Figure 7 and Figure 8 As can be seen from the figure, the beams 16 are hollow and have an overall rectangular cross section. Advantageously, the beams 16 have the same geometric shape. They can be cut to the same metal profile.

[0083] On each beam 16, two clamping devices 20 are positioned adjacent to each other, more precisely at Figure 2 、 7In the configurations of 1 and 8, one clamping device is located above the other, 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 yarn extending direction within the yarn layers L1 and L2. Figure 2 、 7 and 8, the yarn layers L1 and L2 are perpendicular.

[0084] The first pair of clamping devices 20 is formed by a lower yarn clamping device 20A1 mounted on the upper beam 16A and an upper yarn clamping device 20B1 mounted on the lower beam 16B. This first pair of yarn clamping devices 20 is used to clamp the first layer L1. This first pair of yarn clamping devices 20 is formed by yarn clamping devices 20A1 and 20B1, which are respectively mounted on the side of each beam 16 facing the other beam.

[0085] 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. This second pair of yarn clamping devices is used to clamp the second layer of warp yarns L2. The second pair of yarn clamping devices is formed by a clamping device 20A2 and a clamping device 20B2 mounted on each beam 16, respectively, on the side of the beam opposite the other beam.

[0086] In the above, reference numerals 20A1, 20A2, 20B1 and 20B2 are used to identify four yarn clamping devices. However, in this embodiment, unless otherwise specified, all four yarn clamping devices are identical, and the description of the universal yarn clamping device identified by reference numeral 20 is applicable to all yarn clamping devices.

[0087] Each yarn clamping device 20 comprises a clamping rail 22 , a clamping rod 24 and two retaining devices 26 , each of which is assembled at a respective longitudinal end of the clamping rail 22 by means of a screw 28 .

[0088] The clamping rail 22 is made of an aluminum profile and has a constant cross section along the longitudinal axis X22 of the clamping rail. Figure 4 It is visible in the figure and is generally C-shaped.

[0089] The clamping rail 22 has an inner cylindrical surface 31 with a circular cross-section of diameter D31 centered on the longitudinal axis X22. This inner cylindrical surface 31 partially defines a clamping volume V22 within the clamping rail 22. This clamping volume opens out on the front surface 23 of the clamping rail 22 via an opening O22, at the level of the two parts 30a and 30b of the inner cylindrical surface 30, also centered on the axis X22, but having a diameter D30 that is smaller than the diameter D31.

[0090] The clamping rail 22 comprises a longitudinal recess 32 which forms a receiving housing for a rubber profile 34 with an overall rectangular cross section and a side plane 36 facing the clamping volume v22 .

[0091] The plane 36 forms the inner surface of the clamping volume V22 within the clamping rail 22 .

[0092] In an embodiment not shown, surface 36 is not planar.

[0093] Y22 defines the transverse axis of the clamping rail 22, which 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 the height or thickness axis of the clamping rail 22, which is perpendicular to the axes X22 and Y22. The axes Y22 and Z22 are parallel to Figure 4 plane, and are respectively perpendicular and parallel to the front surface 23.

[0094] 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.

[0095] 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°, relative to the main plane P22 of the rail 22, which contains 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.

[0096] Surfaces 31 and 36 are substantially flush relative to the rubber profile 34 at locations opposite the opening O22. Together with portions 30a and 30b of surface 30, they define a clamping volume V22.

[0097] 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 continuously along the axis X22 is located next to the clamping volume v22 .

[0098] like Figure 7 As shown, the rubber profile 34 of the yarn clamping device 20A1 or 20A2 mounted on the upper beam 16A is located within the corresponding clamping track 22, downwards relative to its clamping volume V22, i.e. on the side of said clamping track which faces along the axis Z22 the clamping track of the other yarn clamping device 20B1 or 20B2 belonging to the same pair of yarn clamping devices 20. Figure 7In the embodiment shown in FIG2 , the rubber profiles 34 of the two upper yarn clamping devices 20A1 and 20A2 are located below their clamping volumes V22, while the rubber profiles 34 of the two lower yarn clamping devices 20B1 and 20B2 are located above their respective clamping volumes V22. In other words, in each yarn clamping device 20, the inner surface 36 of the rubber profile 34 is located on a single side of the clamping volume V22 relative to the main plane P22, and this single side faces the other clamping device 20 of the same pair along the axis z22.

[0099] One or more spacers 38 may be received within the longitudinal recess 32 of each clamping rail 22 in order to adjust the protruding position of the inner surface 36 within the clamping volume v22 .

[0100] The clamping rod 24 extends along a longitudinal axis X24 which is parallel to the axis X22 at least in the installed configuration of the clamping rod 24 within the clamping volume V22 .

[0101] like Figure 3 and Figure 10 As shown, the clamping rod 24 comprises a central portion 42 configured to be housed within the clamping volume V22, two end portions 44 having a substantially square cross-section, and two intermediate portions 46. Each intermediate portion 46 is located along the axis X24 and between the central portion 42 and one of the end portions 44, i.e., on a longitudinal side of the central portion 42.

[0102] The cross section of the clamping rod 24 along its central portion 42 is Figure 4 is visible on the top, while its cross section along a middle portion 46 is Figure 5 It is visible above.

[0103] At the level of its central portion 42, in particular Figure 4 As can be seen from the top, the clamping rod 24 is cylindrical, with a truncated circular cross-section defined along a portion of its outer circumference. A circular surface 48 centered on the axis X24 has a diameter D1, and a flat surface 50 extends over the remainder of the rod. The outer dimension D2, measured perpendicular to the axis X24 between the flat surface 50 and the distalmost portion of the circular surface 48, is strictly smaller than the diameter D1. Therefore, the clamping rod 24 exhibits a non-circular profile in cross-section in a plane perpendicular to the axis X24. P24 denotes the principal plane of the rod 24, which includes its longitudinal axis X24 and is parallel to the flat surface 50. The maximum outer dimension of the rod 24's non-circular profile extends parallel to the principal plane P24 and is equal to the diameter D1. This diameter D1 is greater than the rod's maximum outer dimension perpendicular to the principal plane P24, namely, the distance d2. Diameter D1 is substantially equal to diameter D30, for example, 36 mm.

[0104] The square cross section of the end 44 of the clamping rod 24 is suitable for cooperating with a tool (not shown), such as a wrench, in order to exert a torque on the clamping rod 24 about the axis X24 .

[0105] At the level of a middle portion 46, in particular Figure 5 As can be seen from the top, clamping rod 24 includes two planar, parallel surfaces 52 and 54, and two surfaces 56 and 58, each in the form of a cylindrical section having a circular base centered on the longitudinal axis. d2' represents the distance between surfaces 52 and 54, measured perpendicularly to these surfaces. Preferably, distance d2' is slightly smaller than dimension d2. D1' represents the diameter of surfaces 56 and 58. Preferably, diameter d1' is slightly smaller than diameter D1.

[0106] Along the axis X24 , the plane 52 of the intermediate portion 46 extends the flat surface 50 of the central portion 42 towards the adjacent end portion 44 , while the plane 54 extends one of the planes of the end portion 44 towards the central portion 42 .

[0107] Each retaining device 26 includes a body 60 secured together by a body portion 62, a support plate 64, and a cover 66. Parts 62 and 66 are provided with holes 68 for passing screws 28. Body portion 62 is also provided with threaded holes 70 for receiving screws 72 that pass through holes 74 in cover 66 and secure cover 66 and body portion 62 together.

[0108] The holding device 26 serves to limit the rotational movement of the clamping rod 24 within the clamping volume v22 .

[0109] The body portion 62 defines a housing H26 for housing the C-shaped retaining member 76. More precisely, the body portion 62 has an internal cylindrical surface 80 having a circular cross-section centered on the central axis X60 of the body 60. The body 62 also has an end wall 82 that axially delimits the housing H26 on one side, while the cover 66 delimits the housing on the other side along the axis X60.

[0110] The end wall 82 and the cover 66 are respectively provided with a central hole 84 and 85 for the passage of the clamping rod 24. The two central holes 84 and 85 have the same geometric shape.

[0111] The main body 62 is also provided with a through-hole 86 extending from the housing H26 to an outer surface 88 of the main body 62. This through-hole 86 forms a housing for a shuttle 90. The shuttle 90 is resiliently biased toward the housing H26 by a spring 92, allowing a rounded end 94 of the shuttle 90, opposite the spring 92, to protrude within the housing H26. A protrusion 93 is provided on the support plate 64 for centering the spring 92. Thus, the support plate 64 cooperates with the main body 62 to support the shuttle 90 within the through-hole 86.

[0112] Y60 denotes the transverse axis of the body 60 , which is perpendicular to the axis X60 and passes through the opening O26 .

[0113] In the mounted configuration of the retaining device 26 on the clamping rail 22, the movement of the shuttle 90 takes place along its longitudinal axis A90, which is parallel to the axis Z22, i.e. transverse to the longitudinal axis X60 and to the axis Y60. The movement of the shuttle 90 towards the housing H26 is limited by a shoulder formed by an annular collar 96 of the shuttle 90, said shoulder abutting against an internal shoulder 98 formed in the through hole 86, as indicated by Figure 5 The movement of the shuttle 90 away from the housing H26 is limited by the support plate 64, which is fixed to the main body 62 by two screws 99, which pass through two holes 100 provided in the support plate 64 and are screwed into two threaded blind holes 101 provided in the main body 62.

[0114] The shuttle 90 is provided with a through hole 102 transverse to its longitudinal axis a90. The through hole 102 is sized to receive the ends of two transverse pins 104 received in oblong slots 106 and 108 in the body portion 62 and the cover 66 respectively.

[0115] In fact, in Figure 6 The transverse pin visible on the left side of the embodiment passes through the slot 108 and the first portion of the slot 106 so as to engage in the through hole 102 while still protruding outside the cover 66. Figure 6 The transverse pin 104 visible on the right side of the embodiment passes through the invisible portion of the slot 106 which connects the through hole 86 to the surface of the body portion 62 perpendicular to the axis X60 and is located at Figure 6 This transverse pin 104 also protrudes from the main body 62. By this arrangement, the transverse pin 104 allows the shuttle 90 to be moved in the through hole 86 against the elastic action of the spring 92 when necessary.

[0116] 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 retaining member 76 has two end surfaces 121, 123 perpendicular to the axis X76, which respectively face the cover 66 and the end wall 82, so that the retaining member 76 is fixed in the housing H26 in a longitudinal direction parallel to the axis X60.

[0117] The body 60 has an opening O26 formed on the side 122 of the body portion 62 and on the edge of the cover 66, and connects the housing H26 to the outside of the body 60. W26 represents the width of the opening O26, which is greater than the distance d2'.

[0118] In the mounted configuration of the holding device 26 at one longitudinal end of the clamping rail 22 , the openings O22 and O26 extend adjacent to one another along the axis x22 .

[0119] Axis Y60 is perpendicular to side surface 122. Z60 defines another transverse axis of body 60, which is perpendicular to axes X60 and Y60 and parallel to side surface 122. Axis Z60 is parallel to the longitudinal direction of through-hole 86 and to longitudinal axis A90 of shuttle 90. Width W26 is measured parallel to axis Z60. Axes X60, Y60, and Z60 are tangential.

[0120] The outer surface 120 of the retaining member 76 matches the inner cylindrical surface 80 defining the housing H26, and the retaining member 76 has the possibility of a limited range of movement within the housing H26 only in the direction of the axis Z60. In other words, as by Figure 5 As can be seen from the comparison of the two upper positions shown, retaining member 76 can move axially within housing H26 to a limited extent along axis Z60. When retaining device 26 is mounted at one end of clamping rail 22, retaining member 76 is housed within housing H26 and cannot be moved out of housing H26 in a transverse direction parallel to axis Y60, and therefore parallel to axis Y22. Overall, housing H26 forms a guide housing that, when superimposed, guides retaining member 76 in rotation about axes X60 and X76.

[0121] Retaining member 76 defines a central recess 124 extending from end surface 121 to end surface 123 and extending between two planar and parallel surfaces 126 and 128 that are parallel to and non-tangential to axis X76. Axis X76 passes through recess 124. Retaining member 76 has a base 130 and two branches 132 and 134 that define planar surfaces 126 and 128, respectively, on either side of recess 124. Recess 124 opens into cylindrical outer surface 120 in a direction opposite to base 130. Recess 124 is configured to receive intermediate portion 46 of clamping rod 24.

[0122] When the yarn clamping device is assembled, a retaining device 26 is mounted at each longitudinal end of the clamping rail 22. The yarn clamping device thus comprises two retaining devices 26, two retaining 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.

[0123] Before the clamping rod 24 is inserted into the clamping rail 22 of the yarn clamping device 20, the yarn layer L1 or L2 is pulled out from the warp yarn beam so as to extend along the front surface 23 of the clamping rail 22. Between the warp yarn beam and the front surface 23, the yarn 200 of each yarn layer L1 or L2 is guided by one of the two rollers 138.

[0124] When the clamping rod 24 is mounted in the yarn clamping device 20, its central portion 42 is inserted into the clamping volume V22 through the opening O22 and has a translation movement parallel to the axis Y22, as shown in FIG. Figure 4 This translation movement A1 causes the two middle parts 46 of the same clamping rod 24 to also pass along the axis Y60 (also indicated by the arrows A1 in the figure) of the two holding devices 26. Figure 5 The clamping rod 24 is inserted into the housing H26 by means of the arrow A1 on the top of the housing (indicated by the arrow A1 on the top of the housing 24).

[0125] This assumes that each retaining member 76 is in the released position, as shown in FIG. Figure 5 The upper portion is shown oriented with surfaces 126 and 128 parallel to axis y60.

[0126] If you can Figure 4 As can be seen from the figure, regardless of the position of the retaining member 76 in the housing H26, the or each opening O26 extends further from the plane containing the axes X60 and Z60 than the opening O22 extends 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.

[0127] Furthermore, the branches 132 of the retaining member 76 extend away from the axis X76 towards the opening O26 , further than the clamping volume V22 extends to the opening O22 .

[0128] In this position, the retaining member 76 does not obstruct the passage of the clamping rod 24 out of the recess 124 .

[0129] Therefore, when the clamping rod 24 is moved along Figure 4 and Figure 5When moving in the direction of arrow A1 in FIG, the plane 52 of the middle part 46 begins to slide on the planes 126 of the two retaining members 76 before the central part 42 enters the clamping volume V22 through the opening 22. Thus, the two planes 126 form a guiding surface for the central part 22 towards the clamping volume v22.

[0130] At the end of the translation movement indicated by arrow A1 , in an extraction movement opposite to the introduction movement of the clamping rod indicated by arrow A1 , the clamping rod 24 is in an insertion position in which the rod 24 can still pass through the opening O22 . In this insertion position, the plane 50 faces the inner surface 36 .

[0131] At this stage, the retaining members 76 of each retaining device 26 are in Figure 5 The top shows a released position in which it does not hinder the movement of the corresponding intermediate portion 46 along the axis Y60 , in the direction of the arrow A1 or in the opposite direction.

[0132] In this release position, which corresponds to the retracted position of the shuttle 90, the rounded end 94 of the shuttle 90 cooperates with the retaining member 76 by sliding contact with the outer cylindrical surface 120 of the retaining member 76. Any rotational movement of the retaining member 76 about its axis x76 is not prevented. The retaining device 26 is in the release configuration.

[0133] When the clamping rod 24 is inserted into the clamping volume V22 and the housing H26 by translation along the axes Y22 and Y60 indicated by the arrows 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 .

[0134] Then, a torque can be applied to at least one end 44 of the clamping rod 24 in order to rotate the rod in the clamping direction about its longitudinal axis X24 within the clamping volume V22. The clamping direction can be defined as the direction of rotation that causes the clamping rod 24 to move relative to the clamping rail 22 from Figure 4 and Figure 5 The insertion position shown at the top continues into Figure 4 and Figure 5 The middle position is shown in the middle, and the Figure 4 and Figure 5 The clamping direction is at the bottom of the Figure 4 and Figure 5 The direction of rotation around the axis X24 is in the direction of the arrow R2.

[0135] Axes X22 and X24 are now coincident.

[0136] The inner cylindrical surface 30 and the circular surface 48 cooperate to guide the rotational movement of the clamping rod 24 in the clamping volume v22. The inner surface 36 at least partially protrudes into a cylindrical volume whose diameter is equal to the maximum dimension of the clamping rod, i.e., the diameter D1, and which is defined in the clamping volume V22 around the axis of rotation X24 of the clamping rod 24.

[0137] Since the intermediate portion 46 and the retaining member 76 are connected together in rotation about the axes X24 and X76, 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, this 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 due to Figure 5 This is indicated by the arrow R2 on the upper side. Thus, cylindrical surface 120 is fixed for rotation with the clamping rod about axis X24. During rotation in the clamping direction R2, outer cylindrical surface 120 of retaining member 76 slides on circular end 94 of shuttle 90 and inner cylindrical surface 80, without being able to move in transverse direction y22. Retaining device 26 remains in the released configuration.

[0138] This brings the clamping lever to Figure 4 and Figure 5 This position is an intermediate position of the clamping rod 24, in which the yarns 200 pass through the clamping volume V22, but are not blocked within this clamping volume as long as they can slide relative to the central part 42.

[0139] In this position, due to the non-circular profile of the clamping rod 24 , the maximum external dimension d24 of the cross section of the central portion 42 of the clamping rod 24 parallel to the axis Z22 is greater than the distance d2 and smaller than the diameter d1 .

[0140] W22 represents the width of the opening O22, measured parallel to the axis Z22, ie perpendicular to the axis y22. W22 is, for example, equal to 30 mm. Preferably, W22 is between 75% and 90% of the diameter d1. W22 is substantially equal to the dimension d2.

[0141] According to an advantageous aspect of the invention, in the middle position of the clamping rod 24, the outer dimension d24 is strictly greater than the width W22, so that the clamping rod 24 is completely locked along its central portion 42 within the clamping volume V22. As long as it cannot be extracted from this volume through the opening O22 simply by moving it transversely along the axis Y22. In other words, the difference d3=d3a+d3b between the maximum dimension d24 and the width W22 is sufficient to block the clamping rod 24 within this clamping volume V22 on the clamping rail 22 by the form fit between the clamping rod and the portions 30a, 30b, thereby creating a holding area. This holding area extends over the entire length of the longitudinal central portion 42 housed in the clamping volume V22 and on both sides of the main plane P22, as shown in FIG. Figure 4 As shown by the two reference numerals d3a and d3b on the upper side, this avoids bending of the clamping rod 24, especially when its length is greater than 3 meters.

[0142] On the other hand, in this position, the second branch 134 of the retaining member 76 is interposed between the clamping rod 24 and the opening 26, thereby preventing the intermediate portion 46 of the clamping rod 24 from passing through the recess 124 and also retaining the intermediate portion 46 within the housing H26. Therefore, this position is a retaining position of the retaining member 76.

[0143] d4 represents 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 main portion, which defines the opening O26 adjacent to the through hole 86. This distance d4 is strictly smaller than the width W26, preferably less than 75% of this width. For example, d4 is equal to 16 mm and W26 is equal to 30 mm.

[0144] D24' represents the maximum outer dimension of the cross-section of the middle portion 46, parallel to the axis Z60, in the intermediate position of the clamping rod 24, i.e., in the retaining position of the retaining member 76. This dimension d24' is preferably less than or equal to the maximum dimension d24. This dimension d24' is strictly greater than the distance d4, so that the clamping rod 24 is locked within the housing H26 by the retaining member 76. In other words, the remaining width (also called the "apparent width") of the opening O26 through the middle portion 46 is reduced to a distance d4 that is less than the dimension d24'. This prevents the clamping rod 24 from being withdrawn from the housing H26.

[0145] Due to the rotation of retaining member 76, shuttle 90 no longer abuts outer cylindrical surface 120, so that its movement toward housing H26 is no longer restricted by retaining member 76. Consequently, shuttle 90 is urged by spring 92 until contact between its collar 96 and shoulder 98 is achieved, causing its circular end 94 to protrude within housing H26 in the blocking position. This occurs automatically due to the action of spring 92 during rotation of retaining member 76 in the clamping direction of arrow R2, without requiring any operator action. The movement of shuttle 90 from the retracted position to the blocking position occurs automatically when clamping rod 24 rotates in the clamping direction from the insertion position to the intermediate position, relative to retaining member 76 and clamping rod 24. In this blocking position, and with clamping rod 24 in the intermediate position, shuttle 90 is in contact with retaining member 76 in a circumferential direction about axes X24 and X76.

[0146] In this configuration, the shuttle 90 is aligned with the retaining member 76. Figure 5 Rotation about axis x76 in the direction of arrow R3 forms an obstacle. In other words, once it has reached the retaining position, with shuttle 90 forming the obstacle in the blocking position, retaining member 76 cannot be returned to its release position by rotating in a direction R3 opposite to clamping direction R2, because this rotational movement is blocked by shuttle 90 forming the obstacle. Therefore, the shuttle can also be referred to as an obstacle for retaining member 76. Retaining device 26 is then in the retaining configuration.

[0147] Since retaining member 76 is connected in rotation to clamping rod 24 about axes X24 and X76 by the cooperation of the shapes of surfaces 52 , 54 , 126 and 128 , retaining member 76 is blocked by the obstacle formed by shuttle 90 , preventing clamping rod 24 from rotating in the direction of arrow R3 .

[0148] The retaining member 76 serves as an interface between the barrier 90 and the portion 46 of the clamping rod 24 .

[0149] Even if the retaining member 76 is blocked in the direction of arrow R3, the obstacle 90 does not block the retaining member in the clamping direction R2, so that in the retaining configuration of the retaining device 26, if the above torque is continued to be applied in the direction of arrow R2, the clamping rod 24 can be moved from the intermediate position to Figure 4 The bottom of the figure shows the clamped position in which the yarn 200 is clamped between its central portion 42 and the inner surface 36 of the rubber profile 34. In fact, the shape and position of the rubber profile 34 are such that, when it is in the clamped position, the joining edge 49 between the surfaces 48 and 50 of the central portion 42 slightly penetrates the rubber profile 34 at the level of the inner surface 36. This ensures proper clamping of the yarn 200 within the clamping volume v22, with the yarn 200 therebetween.

[0150] From the intermediate position to the clamping position, the obstructing shuttle 90 does not move relative to the body 60 and the retaining member 76 has no transverse movement along the axis y20 .

[0151] In the clamping position of the clamping lever 24 , the holding member 76 is in a third position different from the holding position, since the clamping lever 24 and the holding member 76 are connected and move together in rotation between the intermediate position and the clamping position of the clamping lever 24 .

[0152] Tensioning devices 140 belong to the frame 12 and allow the position of the upper beam 16A to be adjusted along the column 14, as shown Figure 7 and 8 As indicated by the double arrow A2 on the upper beam 16A, a tensioning device 140 is mounted between each column 14 and the upper beam 16A. The direction of adjustment 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 axis Z22 of the clamping rails of the four yarn tensioning devices 20. Each tensioning device 140 includes a spindle 142, which is actually movable and connected to the upper beam 16A via a bracket 144. The first spindle can be operated by an operator using a ratchet wrench (not shown), and its rotational movement is transmitted to the other spindles, which form the driven spindles, via one or more synchronization chains 146.

[0153] On the other hand, the lower cross member 16 is mounted on the column 14 without any possibility of movement.

[0154] 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 , thereby adjusting the tension of the yarns of the first and second layers L1 and I2 .

[0155] The yarn frame 12 is mounted on some columns 150 of the fixed structure 4 of the drawing-in machine 2, with a variable inclination relative to this fixed structure. This is achieved by a system of articulated levers 152 hinged on the columns 150. Each lever 152 is associated with a gas spring 154. Thus, when the yarn frame 12 is essentially horizontal, the operator can prepare for the clamping and tensioning of the layers L1 and L2, i.e., orient the opening O22 of the clamping rails 22 of the yarn frame 12 upwards, which in the vertical direction faces the top. Before starting the drawing-in process, the yarn frame is tilted back to Figure 2 、 7 and the vertical threading position shown in 8.

[0156] Alternatively, the yarn frame 12 may be stationary relative to the fixed structure 4 .

[0157] The relative movement of the drawing-in unit 8 relative 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 process. The user can make use of the teachings of US Pat. No. 5,381,594 or EP-A-2,199,443.

[0158] In the case shown in the figure, in which the drawing-in process is carried out with a single drawing-in unit 8 having yarns 200 taken from two warp yarn layers L1 and L2, the lower beam 16 supports two clamping devices 20 and the upper beam 16 supports two further clamping devices.

[0159] In the case of a drawing-in process using yarns 200 taken from a single warp layer, a single clamping device 20 can be mounted on each beam 16 .

[0160] In the drawing-in machine shown in the figures, the clamping rail 22 of each clamping device 20A2 and 20B2 of the second pair of clamping devices is movable along the corresponding beam supporting it, that is, parallel to its longitudinal axis x22. In this regard, the clamping rail 22 is controlled by a dedicated adjustment device 160. This adjustment device 160 comprises a nut 162, which is threadedly engaged with a spindle 164 and is guided along the axis x22 by a guide rail 165 fixed to the main structure of the yarn frame 12. The bevel gear 166 driven by the crank handle 168 drives the rotation of the main shaft 164, so that the nut 162 is displaced in a direction parallel to the axis X22 of the clamping rail, as indicated by the arrow A3 in the figure. In Figure 2 In FIG, the adjusting device 160 is shown separated from the yarn frame 12 and separated on a larger scale. Figure 9 In FIG. 1 , the upper adjusting device 160 is shown in its configuration for use on the yarn frame 12 .

[0161] Each adjustment device 160 also includes a bolt 170 that is threaded into its nut 162. The bolt 170 of the lower adjustment device 160 is not shown. Figure 2 Each bolt 170 is configured to be screwed into a threaded hole 172 located near one end of the clamping rail 22 of the yarn clamping device 20A2 or 20B2.

[0162] Each longitudinal end of the clamping rail 22 has a cutout 174 for receiving a retractable support 176 .

[0163] The cooperation of the bolt 170 and the threaded hole 172 allows the translational movement of the nut 162 of the adjustment device 160 along its track 165 to be transmitted into the clamping track 22 of the associated yarn clamping device 20A2 or 20B2, which translates along its longitudinal axis x22.

[0164] like Figure 10 As shown, an interface 179 is inserted longitudinally between the main body 60 of the retaining device 26 and the longitudinal end of the clamping rail 22 on the longitudinal side of the adjustment device. This interface 179 is fixed to the main body 60 by screws 28. This interface is fastened to the nut 162 by screws 181, which extend through the nut 162 parallel to the bolt 170 and engage in the threaded hole of the interface. Then, because the nut 162 is fixed to the end of the clamping rail 22 and connected to the interface 179, the adjacent retaining device 26 is indirectly fixed to the clamping rail 22.

[0165] 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 a number of guide protrusions 180 that are regularly distributed along the entire length of the beam 16. In practice, a group of two protrusions 180, arranged respectively above and below the clamping rail 22, together form a guide group 182. Figure 9 As shown, the guide groups 182 are distributed along the length of the beam 16. The two protrusions 180 of the guide groups 182 are aligned along a direction parallel to the yarns 200 in the yarn layer L1 or L2, ie along a direction parallel to the axis z22.

[0166] On the other hand, each clamping rail 22 is provided with two longitudinal slots 184 configured to house each protrusion 180 and, if this clamping rail 22 is associated with the adjustment device 160 , to slide on this protrusion when the nut 162 moves along the rail 165 .

[0167] 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 beam 16 and at the level of the yarn separation zone YSZ located between the upper and lower beams 16.

[0168] Furthermore, the upper yarn clamping device 20A2 of the second pair of yarn clamping devices is partially detachably mounted on the main structure of the yarn frame 12, in particular on its upper beam 16. To allow for detachable mounting of the clamping rail 22 on the yarn frame 12, the walls of the two longitudinal slots 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 groups 182 along the longitudinal direction of the upper beam 16A. The length L186 of the cutouts, measured parallel to the axis X22, is greater than the length L180 of each protrusion 180, measured parallel to the longitudinal direction of the beam 16A.

[0169] This allows, after the cutouts 186 have been aligned with these guide groups 182, to introduce the clamping rail 22 of the yarn clamping device 20A2 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. Figure 9 and 10 This is indicated by arrow A4 on the upper portion. The clamping rail 22 can then be slid along its longitudinal axis X22 so that the projection 180 engages in the longitudinal groove 184, thereby blocking the clamping rail 22 along the axis Y22 and the axis Z22 on the upper beam 16 by means of a bayonet movement. After this bayonet movement, the threaded hole 172 is aligned with the bolt 170, and the connection between the nut 162 and the clamping rail 22 can be made by means of the bolt.

[0170] Preferably, before engaging with the guide device 182, the clamping rail 22 of the yarn clamping device 20A2 has already been fastened to the retaining device 26 by means of screws 28 on its longitudinal side opposite the threaded hole 172 and the adjusting device 160. The interface 179 and the retaining device 26 on the longitudinal side of the adjusting device 160 have already been fastened to the main structure of the yarn frame 12.

[0171] The yarn clamping device 20A2 is partially detachably mounted on the longitudinal beam 16 of the yarn frame 12, which only requires a threaded connection formed by bolts 170 and threaded holes 172 to mount the clamping rail 22 already equipped with a holding device 26 on the main structure of the yarn frame 12.

[0172] When it is fixed in the longitudinal direction to the associated movable clamping rail 22, each holding device 26 of the yarn clamping device 20A2 or 20B2 follows the translational movement of the clamping rail.

[0173] In an alternative embodiment of the invention not shown, the retaining devices 26 can be stationary relative to the yarn frame 12 and the intermediate portion 46 of the clamping rod 24 slides inside the retaining devices when the clamping rail 22 moves along its axis X22 between the retaining devices.

[0174] In another alternative embodiment of the present invention not shown, when the yarn is first pulled out from the warp beam on the lower beam 16B side and then on the upper beam 16A side, the detachable yarn clamping device is the lower yarn clamping device 20B2 installed on the lower beam 16B.

[0175] In practice, in order to avoid as much as possible the disturbance of the yarn distribution in the yarn layer L1 along the width of the yarn layer, the length L180 of each protrusion 180 along the longitudinal direction of the upper beam 16A should be kept as small as possible. Figure 9 and 10As shown, yarn separation at the level of the guide group 182 results in disturbance zones Zd in the yarn distribution along the yarn width of the yarn layer L1. These disturbance zones can be reduced by keeping the length L180 small.

[0176] 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, in particular with two opposite longitudinal grooves 184. In this case, as Figure 7 and Figure 8 As shown, some protrusions 180 located between two adjacent clamping rails 22 mounted on the same beam 16 engage in a first longitudinal groove 184 of a first clamping rail 22 belonging to a first pair of yarn clamping devices 20, and engage in a second longitudinal groove 184 of an adjacent clamping rail 22 belonging to a second pair of yarn clamping devices 20.

[0177] In the following, a method for clamping a yarn 200 of a yarn layer L1 or L2 using the yarn clamping device 20 is described in conjunction with a single yarn clamping device 20 .

[0178] At the beginning of the process, the yarn 200 is pulled out from the warp yarn beam so as to cover the front surface 23 of the clamping track 22 forming the opening 22. In this configuration, the yarn 200 is located outside the clamping volume V22 of the yarn clamping device 20.

[0179] At this stage, both maintenance devices 26 are in the released configuration. For each retaining member 76 , the notch 124 faces the opening O26 .

[0180] In the released position of the two retaining members 76, the clamping rod 24 can be inserted into the clamping volume V22 and the housing H26 by translating parallel to the axes Y22 and Y60 in the direction of arrow A1. Due to the direction of this translation, the clamping rod 24 pushes the yarns and deflects them into the clamping volume v22. If the clamping rod 24 extends parallel to the axis X22 during its insertion movement, the action of the clamping rod 24 on the yarn 200 is uniform across the width of the yarn layer parallel to the axis X24. During this translational movement, once the middle portion 46 of the clamping rod 24 passes through the opening O26, the plane 50 of the clamping rod 24 is oriented toward the rubber profile 34, and the plane 54 slides along the plane I26.

[0181] The movement of the clamping rod 24 is guided toward the clamping volume V22 via the recess 124 formed in the retaining member 76. Specifically, during the translational movement indicated by arrow A1, the flat surfaces 52 and 54 of the central portion 46 of the clamping rod 24 slide along the flat surfaces 126 and 128 of the retaining member 76 and are guided toward the bottom 130 of the recess 124. Because the distance between the opening O26 and the axis X60, as measured along the axis Y60, is greater than the distance between the opening O22 and the axis X22, as measured along the axis Y22, the guided engagement 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 central portion 46 abuts the bottom 130 of the two recesses 124.

[0182] Since the distance d2 is slightly smaller than the width W22 and the distance d2' is smaller than the width w26, translational movement of the rod in the direction of the arrow A1 through the openings O22 and O26 is possible. In other words, in the released position of the retaining member 76, the clamping rod 24 can be completely aligned with the openings O22, O26 without any part of the yarn clamping device 20 intervening.

[0183] The clamping rod 24 is then in its inserted position within the clamping rail 22. From this position, the rod 24 can still be withdrawn from the clamping volume V22 if necessary. The retaining member 76 is in its released position.

[0184] From the inserted position of the clamping rod 24, the retaining member 76 is pushed by the rounded end 94 of the shuttle 90, which causes a slight displacement of the retaining member 76 within the housing H26, parallel to the axis Z60, in a direction away from the support plate 64. The outer cylindrical surface 120 of the retaining member 76 abuts against the portion of the inner cylindrical surface 80 opposite the through hole 86. This allows the rotation of the retaining member within the housing H26 to be guided by the cooperation of the surfaces 80 and 120.

[0185] The axes X22, X24, X76 and X60 are then superimposed and form a common longitudinal axis X20 of the thread clamping device 20. Each longitudinal beam 16 extends parallel to the common longitudinal axis x20.

[0186] Then, the clamping rod 24 is rotated about 40° about the common center axis X20 in the clamping direction indicated by the arrow R2. Figure 4 and Figure 5 This also allows the retaining member 76 to enter its intermediate position in the middle part of the Figure 590 . 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 end 133 of its branch 132 is angularly displaced relative to the obstruction formed by the shuttle 90. In this position, the spring 92 pushes the obstruction formed by the shuttle 90 toward the housing H26, causing it to protrude from the inner cylindrical surface of the housing H26 and its collar 96 to abut against the shoulder 98, as described above. Any rotational movement of the retaining member 76 in the direction indicated by the arrow R3 and opposite to the clamping direction R2 is then blocked by the shuttle 90 forming the obstruction, against which the end 133 abuts.

[0187] In the intermediate position of the clamping rod 24, there is a gap between the surface 36 and the surfaces 48 50, which allows the yarn 200 to move along its extension direction also within the clamping volume v22. Then, as explained below, if necessary, the yarn 200 can be distributed along the axis X22 and / or the tension of the yarn can be adjusted.

[0188] In the retaining position of the retaining member 76 , the intermediate portion 46 of the clamping rod 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.

[0189] When the retaining 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 rod 24, it further reduces the remaining width of the passage for the clamping rod 24 out of the recess 124. This width is equal to zero in the third position of the retaining member 76, as shown in FIG. Figure 5 As shown in the lower part.

[0190] In the intermediate position of the clamping lever 24 and during rotation from this intermediate position to the clamping position of the lever in the clamping direction R2, the yarn exerts a force on the clamping lever 24 that tends to push the clamping lever 24 out of the clamping volume V22 through the openings O22 and O26, causing the clamping lever to rotate in a direction opposite to the clamping direction. The intermediate portion 46 is retained within the housing H26 by the retaining member 76, so that the central portion 42 remains 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 lever 24.

[0191] In the intermediate position, the obstruction formed by the shuttle 90 does not prevent the retaining member 76 from rotating further in the clamping direction R2 toward the clamping position. Thus, as described above, the clamping lever 24 can be moved from the intermediate position to the clamping position by a form fit, with the retaining member 76 being driven between these two positions by the clamping lever 24. The shuttle 90 is in its blocking 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.

[0192] The third position corresponds to a rotation of the retaining member 76 about the common axis X20 relative to the release position by approximately 90°. Between the intermediate position of the clamping lever and the clamping position, the minimum distance between the clamping lever 24 and the inner surface 36 decreases. In the clamping position, and as described above, this minimum distance causes the yarn 200 to be compressed between the clamping lever 24 and the inner surface 36 of the rubber profile 34, which ensures that the yarn 200 is clamped regularly along the length of the clamping track 22. While clamped, the yarn 200 cannot move within the clamping volume V22 between the inner surface 36 and the clamping lever 24 if it is subjected to the normal effects of the warp preparation process, such as the drawing-in process.

[0193] In the clamped position, the planes 50 , 52 , 54 are globally parallel to the axes Z22 , Z60 , which are perpendicular to the transverse direction defined by the axes Y22 , Y60 .

[0194] When the clamping lever 24 is rotated in the clamping direction R2 between the intermediate position and the clamping position, the difference d3 between the maximum dimension d24 and the residual width W22 in the clamping position is equal to Figure 4 The sum of the differences d3a and d3b, which are represented by the center of , is still sufficient to form a holding region within the clamping volume V22 for retaining the clamping rod 24 within this volume.

[0195] To release the clamping action of the clamping rod 24 on the yarn 200, the rod 24 folds back about the common axis x20 in a direction R3 opposite to the clamping direction. During this movement, the retaining member 76 holds the corresponding intermediate portion 46 within the volume H26. When the intermediate position is reached again, because the retaining device is still in the retaining configuration, the obstacle formed by the shuttle 90 prevents the retaining member 76 from rotating further in the direction of arrow r3. The operator can then push one or both of the two transverse pins 104 protruding from the slots 106 and 108 toward the support plate 64, overcoming the elastic force of the spring 92. This returns the shuttle 90 to the retracted position. The obstacle retracts into 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 to the clamping direction of arrow r2. This allows the retaining member 76 to return to its released position, where the outer cylindrical surface 120 of the retaining member 76 slides over the circular end 94 of the shuttle 90.

[0196] 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 , the operator can move the shuttle 90 from its blocking position to its retracted position.

[0197] When the retaining member 76 is in its release position, the operator can release the transverse pin 104 and the rod 24, returned to its inserted position, can be removed from the clamping volume V22 and the two housings H26 by a translation movement through the openings O22 and O26 in a direction opposite to one of the arrows a1.

[0198] During an optional release process, while the retaining device 26 is still in the retained state, the clamping rod 24 can be rotated from its clamping position to its insertion position in the clamping direction of arrow R2. In this case, the end 135 of the branch 134 abuts the rounded end 94 of the shuttle 90 and pushes the shuttle into the through hole 86 against the elastic force of the spring 92. This causes the outer cylindrical surface 120 to slide in contact with the rounded end 94. The obstacle 90 returns to the retracted position and the retaining device 26 is in the released configuration. As the rotational movement of the clamping rod 24 in the clamping direction of arrow R2 continues, it allows the retaining member 76 to reach the released position, in which the clamping rod 24, returned to its inserted position, can be removed from the volume V22 and the housing H26, just as in the first release process.

[0199] In a second loosening process, the clamping rod 24 and the retaining member 76 are opened 360° in the direction of arrow A1 between the volume V22 and the housing H26 and are removed from these volumes and the housing in the direction opposite to arrow a1.

[0200] A method for clamping and tensioning the two yarn layers L1 and L2 with the yarn frame 12 will be described below.

[0201] First, when the yarn 200 of the first layer L1 is pulled out from the warp beam and placed in front of the front surface 23 of the clamping track of the first pair of yarn clamping devices 20A1 and 20B1, the detachable yarn clamping device 20A2 is partially removed from the upper beam 16A of the yarn frame 12. In this configuration, the yarn 200 extends along the yarn extending direction, which is in the direction of Figures 2 to 5 and Figures 7 to 10 The yarns 200 are stretched so that they extend at least to the height of the brush rollers 189 extending parallel to the lower beam 16B and below the lower beam 16B. The engagement between the yarns and the brush rollers 189 causes friction on the yarns, which helps distribute the yarns along the axis X22 of the two yarn clamping devices. The retractable support 176 of each of the two yarn clamping devices 20 is then brought to Figure 7 The extended position shown in dashed lines in FIG. 2 and the clamping rod 24 is placed on each of these supports in front of each clamping rail 22 of the pair of yarn clamping devices. The plane 50 faces the other clamping rod 24 of the first pair of yarn clamping devices. At this stage, each clamping rod 24 is located outside the clamping volume v22.

[0202] The operator then moves each clamping rod 24 into the associated volume V22 and housing H26 , with a translation movement in the direction of the arrow A1 towards the insertion position of the clamping rod.

[0203] The operator then engages a wrench with the end 44 of each clamping rod 24 to bring each clamping rod 24 into its neutral position. In either position of the clamping rods 24, the operator can distribute the yarns 200 of the first layer L1 along the longitudinal direction of the beam 16. In these positions of the clamping rods 24, the yarns 200 of the first layer L1 do not have the same tension within the layer because they do not engage the brush rollers 189 equally. The tensioning device 140 can be used to spread the beams 16A and 16B relative to each other, thereby leveling the yarn tension within the yarn layer L1. In summary, the neutral position enables a uniform tension to be achieved within the yarn layer L1.

[0204] The operator can then rotate the two clamping levers 24 to bring them into their clamping position, thereby achieving a clamped configuration of the yarns 200 of the first layer L1. The operator releases the tensioning device 140 in order to release the tension in the first yarn layer L1.

[0205] In a variant embodiment, one of the two clamping rods 24 cooperating with the first layer L1 is first rotated in the clamping position and the operator then uses the tensioning device 140 to achieve a regular tension in the yarn layer L1 before clamping the other of the two clamping rods 24 .

[0206] Then, the yarns 200 of the first yarn layer L1 at the longitudinal level of the guide groups 182 are divided and arranged on both sides of each guide group 182, as shown in FIG. Figure 9 and 10 As shown in the area Zd on the top.

[0207] Guide rods 188 are mounted on the upper beam 16A to force the yarn of the first layer L1 to follow a path close to the beam 16A and the yarn clamping device 20A1 and to maintain a free volume for receiving the yarn clamping device 20A2.

[0208] The yarns of the first warp layer are cut just below the first pair of lower yarn clamping devices 20B1 and no longer cooperate with the brush roller 189.

[0209] 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 accordingly moved along its common axis x20. The clamping rail 22 of the detachable yarn clamping device 20A2 then engages the guide 182 and is screwed to the nut 162 of the associated adjustment device 160 via the bolt 170, as explained above.

[0210] 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. Figure 7 and 8 shown.

[0211] The yarns 200 of the second warp layer L2 are pulled from the warp beam to the brush roller 189 at the point of contact of the front surfaces 23 of the two clamping rails 22 of the second pair of clamping devices 20.

[0212] For the first level, the retractable support 176 extends and reaches Figure 7 The position indicated by the dashed lines is assumed, and the clamping rod 24 is placed on these supports, with the plane 50 facing the other clamping rod 24 of the second pair of yarn clamping devices. It is then pushed in the direction of arrow A1 within the two clamping rails 22 and rotated as explained above. When the clamping rod reaches its intermediate position, the operator can distribute the yarns 200 of the second warp layer L2 along the longitudinal direction of the beam 16, using the tensioning device 140 to balance the yarn tension along the width 200 of the second warp layer L2 to a tension equivalent to that of the yarn layer L1.

[0213] The operator can then rotate each clamping lever 24 of the yarn clamping devices 20A2 and 20B2 in a rotational clamping direction so that the yarn 200 of the second warp yarn layer L2 is clamped in a clamping position within the clamping tracks 22 of the two clamping devices of the second pair of yarn clamping devices.

[0214] Then, the tensioning device 140 is used to spread out the two beams 16 in order to increase the tension of the yarns in the warp yarn layers L1 and I2.

[0215] At the end of the warp yarn layer preparation, the two warp yarn layers extend substantially in the same plane between the upper clamping rail 22 and the lower clamping rail 22, as shown in FIG. Figure 7 and Figure 8 shown.

[0216] Then, the two warp yarn layers L1 and L2 are in Figure 2 In a configuration in which they extend essentially 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.

[0217] In this regard, the drawing-in unit 8 may include a single separating device for the two layers L1 and L2, as disclosed in CN-U-211036281, with a separating cord between the two layers L1 and L2. During the drawing-in process, if the warp yarn layers L1 and L2 must be moved relative to each other in a longitudinal direction parallel to the axis X20, each clamping rail 22 associated with the adjustment 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 relative to the fixed structure 4 and the first yarn layer L1 in the direction of arrow a3, parallel to the longitudinal direction of the beam 16. During this movement, the protrusion 180 guides the translation of the clamping rail 22 relative to the beam 16.

[0218] If yarn preparation occurs with the yarn frame in an inclined configuration, the use of the retractable support 176 is not necessary.

[0219] exist Figure 9 and Figure 10 In FIG. 1 , the yarn frame 12 is shown when used with a single yarn layer L1, but it can also be used with two yarn layers, such as Figure 1 、 2 , 7 and 8. Therefore, the yarn frame 12 is universal.

[0220] exist Figure 11 and 12 In the second and third embodiments of the yarn clamping device according to the invention shown, elements similar to those of the first embodiment are provided with the same reference numerals. Hereinafter, only the differences from the first embodiment will be mentioned. Figure 11 and 12If a reference numeral is used in one of the embodiments and is not mentioned in the following description, it designates the same part of the yarn clamping device as the part having the same reference numeral in the first embodiment.

[0221] exist Figure 11 In the second embodiment, the retaining member 76 has an L-shaped cross section, and the obstacle is formed by a rotating rod 90 .

[0222] The retaining member 76 defines a recess 124 in the shape of a dihedron having a base 130 and branches 132 forming a plane 126. The lever 90 is rotatable about an axis 190 fixed relative to the body 60 of the retaining device 26. The lever 90 is urged toward the Figure 11 The end 94 of the lever 90 is movable in a housing 602 defined between the main portion 604 of the body 60 and a rod 606 of the body 60 defining the opening 26 adjacent to the lever 90. This housing 602 is transverse to the longitudinal axis X24 of the clamping rod 24 and thus to the axis of rotation X20 as defined in the first embodiment.

[0223] The clamping rod 24 is hollow in its central portion 42 and in its intermediate portion 46 and has two outer flat surfaces 52 and 54 and two outer surfaces 56 and 58 in the form of circular arcs whose cross-sections are centered on the longitudinal axis X24 of the clamping rod. The dimension d2 defined between and perpendicular to the surfaces 52 and 54 is smaller than the width W22 of the opening O22 as defined in the first embodiment.

[0224] When the clamping rod 24 is inserted into the housing H26 of the holding device 26 through the opening O26 and into the clamping volume V22 through the opening O22, Figure 11 In the direction of top arrow A1, plane 54 slides on plane 126 to a point where cylindrical surface 56 contacts bottom 130. In this position, outer cylindrical surface 120 of retaining member 76 holds lever 90 in a retracted position away from its blocking position.

[0225] During the rotation of the lever 24 in the housing H26 between its insertion position and its intermediate position in the clamping direction indicated by the arrow R2, the end 133 of the branch 132 leaves the end 94 of the lever 90. This makes the lever automatically reach its blocking position under the elastic force exerted by the spring 92. This movement of the lever 90 between its retracted position and its blocking position occurs relative to the retaining member 76 and thus relative to the clamping lever 24. Figure 11 As shown in the center of FIG, in the locked position of the lever 90, its end 94 protrudes into the housing H26. Figure 11In the intermediate position shown in the center of the figure, the retaining member 76 is in the retaining position, in which the end 133 abuts the lever 90 in a 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 to the clamping direction R2. Therefore, the lever 90 can also be referred to as a barrier for the retaining member 76. The retaining device 26 is then in the retaining configuration. In this intermediate position, the clamping lever 24 engages the lever 90 via the retaining member 76 and is blocked by the retaining member 76 against rotation in the direction R3 opposite to the clamping direction R2 about the axis X60 due to the contact between the flat surface 54 and the flat surface 126.

[0226] In this retaining position of this second embodiment, the retaining member 76 does not restrict the remaining width of the recess 124. The clamping lever 24 is retained 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 retaining zone due to the shape fit between the clamping lever 24 and the clamping rail 22.

[0227] 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 Figure 11 In the clamping position shown at the bottom of the figure, the clamping rod 24 presses the yarn against the inner surface of the clamping volume V22 for clamping.

[0228] During movement of the clamping lever 24 between the inserted position and the clamped position, the outer cylindrical surface 120 of the retaining member 76 slides relative to the inner cylindrical surface 80 of the main body 60 .

[0229] exist Figure 12 In the third embodiment, the retaining device 26 comprises an obstacle formed by a sliding bolt 90 urged toward the housing H26 by a spring 92, but lacks a retaining member comparable to the retaining member 76 of the first and second embodiments. In this third embodiment, the obstacle 90 is fixed directly within the body 60 and cannot rotate about the axis X60. This is because it is housed in a through hole 194 drilled directly into the body and extending parallel to an axis A90 transverse to the longitudinal axis X60 and the axis Y60.

[0230] The clamping rod 24 has an outer plane 52 and an outer surface 56 in the form of an arc of a circle, the cross section of which is centered on the longitudinal axis X24 of the clamping rod.

[0231] In this third embodiment, the retaining device is made directly in the clamping rail 22. In other words, the body 60 is formed in a portion of the clamping rail 22 in which a through hole 194 is drilled.

[0232] Here, the obstacle 90 can slide relative to the housing H26 and the main body 60, and thus can slide relative to the clamping rod 24. Figure 12 In the example of FIG. 1 , the obstacle 90 can be moved between the retracted position and the blocking position along the directions indicated by the arrows A5 and A6, which are perpendicular to the two axes X60 and X24 and perpendicular to the direction of introduction of the clamping rod 24 in the housing H26, which is also indicated by Figure 12 The arrow A1 on the top indicates.

[0233] In the inserted position, and between the inserted position and the intermediate position, when the clamping rod 24 is rotated in the clamping direction R2, the obstruction 90 is in a retracted position with its end 94 in contact with the outer flat surface 52 of the clamping rod 24. The retaining device 26 is in the released configuration.

[0234] At the longitudinal height of the obstacle 90, a recess 187 is provided in each intermediate portion 46 of the clamping lever 24, which is recessed in the clamping rail 22. In the blocking position of the obstacle, that is, when the clamping lever 24 is moved in the clamping direction indicated by arrow R2 between its intermediate position and its clamping position, as in the first embodiment, the recess receives the end 94 of the obstacle 90, 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 recess 187 by a spring 92 mounted in a through-hole 194 and secured therein, for example, by a plate (not shown) supporting the plate 64, similar to the plate of the first embodiment.

[0235] In this intermediate position, the first surface 191 defining the recess 187 cooperates with the obstacle 90 by directly abutting against the end 94 in the circumferential direction around the axis X20 and in the direction of the arrow R3 opposite to the arrow R2. Figure 5 The clamping rod 24 cannot rotate in a rotational direction R3, which is opposite to the clamping direction R2, by rotating about the axis X76 in the direction of the arrow R3. The clamping rod 24 is retained in the clamping volume V22 by the difference d3 between, on the one hand, the maximum dimension d24 of the rod parallel to the axis Z60, and, on the other hand, the width W22 of the opening O22 at the same longitudinal level. Here, the openings O22 and O26, as defined in the first embodiment, are identical.

[0236] During the movement of the clamping lever 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-opening 194 , and does not move relative to the clamping rail 22 .

[0237] Starting from the clamping position, if the clamping lever 24 is rotated further in the clamping direction R2 toward the insertion position, the second surface 193 defining the recess 187 comes into contact with the inclined surface 93 of the end 94 to push the obstruction 90 into its retracted position. Figure 12 In the direction of the arrow A6 visible at the bottom of the housing, against the action of the spring 92. This brings the retaining device 26 into its released configuration.

[0238] In the drawing-in machine 2 and the tying device 3 (tying-installation), the yarn clamping device 20 of the second and third embodiments can be used instead of the yarn clamping device of the first embodiment.

[0239] In an embodiment of the invention which is not shown, only one yarn clamping device or only some of the clamping devices of the yarn frame are according to the invention.

[0240] In another embodiment, in particular if the yarn frame is used to process a single yarn layer, the yarn frame may comprise a single pair or yarn clamping devices.

[0241] In another embodiment, a single yarn clamping device may be used to clamp yarns of different overlapping yarn layers.

[0242] In an alternative embodiment not shown, the lowermost and uppermost clamping devices 20A2 and 20B2 are fixed to the upper and lower beams 16 and cannot be translated along the axis X22, while the other two clamping devices 20A1 and 20B1, i.e., the clamping devices that operate the first layer L1, can be moved along the beam 16 under the action of the adjustment device 160.

[0243] The angles of 40° and 90° mentioned above may vary. The first angle may be between 30° and 55°, depending on the position of the inner surface 36 within the clamping volume v22. The second angle may be between 80° and 100°.

[0244] In another alternative embodiment, the yarn clamping device 20 includes a single retaining device 26, which is mounted at the first end of the clamping rail 22 and is adapted to cooperate with the intermediate portion 46 positioned adjacent to the first end of the clamping rod 24. A rod retainer is located at the second end of the clamping rail and is adapted to retain the second end of the clamping rod relative to the intermediate portion relative to the clamping rail. In this case, the second end of the clamping rod is first inserted into the rod retainer, and the clamping rod is then tilted so that its central portion enters the clamping volume and its intermediate portion enters the housing of the retaining device. During the insertion of the clamping rod, the rod does not undergo a purely translational movement and is tilted relative to the longitudinal axis of the clamping rail.

[0245] In another embodiment, the body 60 is provided with an indexing pin that projects from 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. This allows the retaining member 76 to move only within a defined angular range between a release position and a third position, which is reached when the clamping rod is rotated in the clamping direction between its insertion position and its clamping position. In this case, a 360° rotation of the retaining member 76 is not possible. Furthermore, in this case, insertion of the clamping rod 24 is not possible in the insertion position, in which the flat surface 50 of the clamping rod 24 does not face the inner surface 36.

[0246] In another embodiment, the translation direction A90 of the slidable obstacle-forming member 90 is not parallel to the axis Z20 but is, for example, inclined relative to the axes Z60 and y60.

[0247] In another embodiment, spring 92 is omitted. In this case, the barrier can be weighted so that it can be moved from its retracted position to its blocking position and held in that position by gravity. In this alternative embodiment of the retaining device, and if the retaining device is manufactured directly in the clamping rail 22 as described in the third embodiment, the retaining device can include only the barrier.

[0248] In another embodiment, the clamping rod is composed of different longitudinal sections (hollow or not) of different cross-sections assembled together.

[0249] like Figure 13 As shown, the yarn clamping device 20 according to the present invention and the yarn frame 12 according to the present invention can also be used in a warp yarn bundling device 3, wherein two pairs of yarn clamping devices 20 are mounted one above the other in a bundling configuration along the axis Z22 of the yarn frame 12. Each pair of yarn clamping devices 20 is dedicated to a warp yarn layer. The yarn frame 12 is configured to guide the translation of the bundling unit 8' along its longitudinal axis X12. As is known, for example, from EP-A-1 943 381, the two pairs of yarn clamping devices 20 can be moved relative to each other along the longitudinal axis X12 to achieve relative movement of two layers extending in two parallel, spaced-apart planes.

[0250] like Figure 11 The frame 12 may be movable and equipped with rollers 13, or in the embodiment shown, may be stationary.

[0251] The embodiments and embodiments listed above can 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 a yarn (200) of a yarn layer (L1, L2), the device comprising - a clamping rail (22) which delimits a clamping volume (V22) extending along a longitudinal axis (X22), a clamping rod (24) configured to be inserted into the clamping volume through an insertion / removal opening (O22) of the clamping rail and in a direction transverse to the longitudinal axis (Y22), a longitudinal portion (42) of the clamping rod housed in the clamping volume having a non-circular cross section, the clamping rod (24) being capable of a clamping rotational movement relative to the clamping rail (22) in a clamping direction (R2) within the clamping volume and about an axis of rotation (X20) parallel to the longitudinal axis of the clamping rail, from an insertion position in which the rod (24) can pass through the insertion / removal opening (O22), and wherein a first outer dimension (d2) of the clamping rod cross section is parallel to a width (W22) of the insertion / removal opening (O22) and is smaller than this width, to a clamping position in which the clamping lever clamps the yarn located in the clamping volume against an inner surface (36) located inside the clamping track, It is characterized in that - The yarn clamping device further comprises at least one holding device (26), the holding device comprising an obstacle (90); - the obstacle is configured to have a movement relative to the clamping rod during the clamping rotational movement of the clamping rod from a retracted position to a blocking position, the retracted position of the obstacle corresponding at least to the insertion position of the clamping rod, whereas the blocking position of the obstacle corresponds at least to an intermediate position relative to the clamping track (22), the intermediate position being reached by the clamping rod during its clamping rotational movement, being offset relative to the insertion position, and wherein the yarn (200) in the clamping volume can be moved between the clamping rod (24) and an inner surface (36) situated inside the clamping track, and wherein a second outer dimension (d24) of the clamping rod cross section is parallel to the width (W22) of the insertion / removal opening (O22) and is strictly greater than this width at the same longitudinal level, - when the obstruction is in its retracted position, the obstruction does not prevent the rotational movement of the clamping lever (24) within the clamping volume between the inserted position and the clamping position, and - When the barrier is in its blocking position and the clamping lever is in the middle position, the barrier does not prevent the rotational movement of the clamping lever within the clamping volume (V22) in the clamping direction (R2) towards its clamping position, and The clamping lever is prevented from rotating within the clamping volume in a direction (R3) opposite to the clamping direction.

2. The yarn clamping device according to claim 1, characterized in that The retaining device (26) also includes a resilient member (92) that urges the obstacle toward its blocking position.

3. The yarn clamping device according to claim 1 or 2, wherein: The obstacle (90) is at least partially housed in a housing (86, 194); the yarn clamping device (20) has the possibility of sliding between a retracted position and a blocking position along a direction (A90) that is transverse to both the rotation axis (X20) and the transverse direction (Y22).

4. The yarn clamping device according to claim 1 or 2, characterized in that: The barrier (90) is movable from its blocking position to its retracted position for all positions relative to the clamping rail (22) reached during the rotational movement of the clamping lever (24) in the clamping direction (R2) between the intermediate position and the clamping position.

5. The yarn clamping device according to claim 1 or 2, characterized in that: In the inserted position, for all positions of the clamping lever (24) reached during the rotational movement in the clamping direction (R2) between the inserted position and the intermediate position, the obstacle (90) is held in the retracted position by a retaining member (76) of the clamping lever (24) or the yarn clamping device, said retaining member (76) being rotationally connected to the clamping lever (24) about the rotation axis (X20).

6. The yarn clamping device according to claim 1 or 2, characterized in that: A retaining element (76) of the clamping lever (24) or of the yarn clamping device, which is rotatably connected to the clamping lever (24) about a rotation axis (X20), is configured to move the obstacle (90) from its blocking position to its retracted position when the clamping lever is rotated in a clamping direction (R2) from its clamping position to the clamping volume (V22) of its inserted position.

7. The yarn clamping device according to claim 1 or 2, characterized in that: The yarn clamping device comprises two retaining devices (26), one at each longitudinal end of the clamping track (22), each retaining device comprising a body (60) containing an obstacle (90), each body (60) being fixed by the clamping track (22), and wherein the clamping rod (24) comprises at least - a first central longitudinal portion (42) housed in the clamping volume (V22) for selectively clamping the yarn (200) on the inner surface (36) located inside the clamping track, and - two second longitudinal portions (46), each situated longitudinally to the first central longitudinal portion (42), housed in the body (60) of the retaining device and adapted to cooperate with the obstacle (90).

8. The yarn clamping device according to claim 1 or 2, characterized in that: The holding device (26) further comprises a holding member (76) which is rotationally coupled to the clamping rod (24) about the rotation axis (X20) between the insertion position and the intermediate position, wherein, in the insertion position, the holding member (76) does not prevent the movement (A1) of the clamping rod (24) through the insertion / removal opening (O22), and wherein, in the intermediate position of the clamping rod, the holding member abuts against the obstacle (90) in a circumferential direction about the rotation axis (X20) to prevent a rotational movement of the clamping rod within the clamping volume (V22) in a direction (R3) opposite to the clamping direction.

9. The yarn clamping device according to claim 8, characterized in that The retaining member (76) has an outer cylindrical surface (120) centered on the rotation axis (X20) and a recess (124) configured to receive the clamping rod (24) when the clamping rod is received in the clamping volume (V22) and is delimited by at least one branch (132, 134) having a plane (126, 128) parallel to the rotation axis, wherein the obstacle (90) is adapted to cooperate with the outer cylindrical surface (120) of the retaining member in the retracted position, wherein the end (133) of the branch (132) is configured to abut against the obstacle (90) in the blocking position in the circumferential direction, and wherein the planes (52, 54) of the clamping rod (24) are in contact with the planes of the recess.

10. The yarn clamping device according to claim 9, characterized in that: In the blocking position of the obstacle (90), at the longitudinal height of the retaining member (76), the retaining member (76) limits the width (W26) of the passage opening (O26) for the clamping rod (24) from the recess (124) to be strictly smaller than the dimension (d24') of the clamping rod parallel to the width of the passage opening.

11. The yarn clamping device according to claim 1 or 2, characterized in that: In the middle position of the clamping rod (24), the surface (191) of the clamping rod abuts against the obstacle (90) in the circumferential direction around the rotation axis (X20) to prevent the clamping rod from rotating in the clamping volume in the direction (R3) opposite to the clamping direction.

12. The yarn clamping device according to claim 1 or 2, characterized in that: - with respect to a main plane (P22) of the clamping volume (V22), which contains the axis of rotation (X20) and intersects the insertion / extraction opening (O22) in the middle of this opening, the clamping volume (V22) is delimited on one side by the clamping rail (22), wherein the other side of the clamping volume is partially delimited by an inner surface (36) belonging to the rubber profile (34) housed in the clamping rail (22), - when the clamping rod (24) is in the middle position, the clamping rod has clearance relative to the inner surface of the rubber profile, and - When the clamping rod is in the clamping position, the clamping rod passes through the inner surface of the rubber profile with the yarn (200) in between.

13. A yarn frame (12) comprising at least one pair of yarn clamping devices (20) spaced apart along a yarn extending direction, characterized in that: At least one of the yarn clamping devices (20) is according to any one of the preceding claims.

14. The yarn frame according to claim 13, characterized in that The yarn frame (12) is configured to clamp the 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 yarn extending direction within the first layer (L1) for clamping the yarn of the first layer (L1), - a second pair of yarn clamping devices (20A2, 20B2) spaced apart in the second layer (L2) along the direction of yarn extension, for clamping the yarn of the second layer (L2), in - the yarn clamping device (20) belongs to a pair of yarn clamping devices and is supported on the longitudinal beam of the yarn frame (12) along the longitudinal axis (X22) of its clamping volume with respect to the other pair of yarn clamping devices and has the possibility of translation (A3), and / or - The yarn clamping devices (20) belong to a pair of yarn clamping devices and, in their clamping configuration, the yarns of the first layer (L1) are interposed between the longitudinal beams of the yarn frame and the yarn clamping devices of the second pair of yarn clamping devices (20A2, 20B2), which are at least partially detachably mounted on the yarn frame.

15. The yarn frame according to claim 13, characterized in that - in the middle position of the clamping lever (24) of the yarn clamping device (20), the surface (191) of the clamping lever abuts against the obstacle (90) in the circumferential direction around the axis of rotation (X20) to prevent the clamping lever from performing a rotational movement in the clamping volume in a direction (R3) opposite to the clamping direction; - The inner surface (36) of the rubber profile (34) is located within the clamping volume (V22) on the same side of the main plane (P22) as the other pair of yarn clamping devices of the same pair (20A1, 20B1; 20A2, 20B2).

16. A drawing-in machine (2) for drawing in warp yarns (200), characterized in that: The drawing-in machine comprises a drawing-in unit (8) and at least one yarn frame (12) according to any one of claims 13 to 15.

17. A method for clamping a yarn (200) of a yarn layer in a yarn clamping device (20), comprising - a clamping rail (22) which delimits a clamping volume (V22) extending along a longitudinal axis (X22), - a clamping rod (24) configured to be inserted into the clamping volume through an insertion / removal opening (O22) of the clamping rail and in a direction transverse to the longitudinal axis (Y22), a longitudinal portion (42) of the clamping rod housed in the clamping volume having a non-circular cross section, said clamping rod (24) having a clamping rotational movement relative to the clamping rail (22) in a clamping direction (R2) within the clamping volume and about a rotational axis (X20) parallel to the longitudinal axis of the clamping rail From the inserted position, the rod can be passed through the insertion / removal opening, to a clamping position in which the clamping lever clamps the yarn located in the clamping volume against an inner surface (36) located inside the clamping track, It is characterized by: The method utilizes an obstacle (90) that is movable relative to a clamping rod (24); - a retracted position corresponds at least to the inserted position of the clamping lever and, in said retracted position, does not prevent a rotational movement of the clamping lever (24) about the axis of rotation (X20), - The blocking position of the obstacle does not prevent the clamping lever from rotating in the clamping direction (R2) within the clamping space towards its clamping position, and The clamping lever is prevented from rotating within the clamping volume in a direction (R3) opposite to the clamping direction from a neutral position relative to the clamping track (22), and wherein: The yarn (200) in the clamping volume is movable between the clamping rod and an inner surface (36) located inside the clamping track, and The clamping rod cannot be moved out of the clamping volume (V22) in the transverse direction (Y22). The method comprises at least the following steps, comprising: a) introducing the yarn (200) and the clamping rod (24) into the clamping volume (V22) while the barrier (90) is in its retracted position; b) Move the clamping lever into its middle position within the clamping volume (V22); c) moving the barrier from its retracted position to its blocking position; d) adjusting the position of the yarn (200) within the clamping volume (V22); and e) Move the clamping lever in the clamping direction (R2) to its clamping position, Steps d) and e) are performed when the obstacle (90) is in its blocking position, During step b), the movement of the clamping lever (24) relative to the clamping rail (22) automatically causes the barrier (90) to move from its retracted position to its blocking position.

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