Rapier, a method for pulling in the weft yarn using the rapier, and a loom including the rapier.

Abstract

A rapier is used to draw the weft yarn into the shed of the loom (2) along a draw-in path. The rapier includes a rapier head (206) mounted at one end of the rapier, the rapier head extending along the main longitudinal axis of the rapier and driven by a drive member along the draw-in path. The rapier also includes a clamp (320) for capturing the weft yarn, the clamp being mounted in the rapier head and operable between an open and closed configuration. The rapier also includes an actuator (208) mounted on the rapier body for actuating the clamp, and a motion conversion mechanism (260 to 328) for converting the output motion of the actuator into an opening or closing motion of the clamp. The actuator is an electric motor (208). Moreover, the output motion of the motor is a rotation about a rotation axis (A208) parallel to the main longitudinal axis (A20) of the rapier (20).

Description

Technical Field

[0001] This invention relates to a rapier for drawing weft yarn from a pick-up position into the shed of a loom. The invention also relates to a method for drawing weft yarn into the shed of a loom and a loom comprising such a rapier.

[0002] The technical field of this invention is the weaving of two-dimensional or three-dimensional fabrics, and more particularly, the technical field of devices for inserting weft yarns into the shed of a loom. Background Technology

[0003] In weaving, a rapier is used to insert the weft yarn through the shed. Most known systems capture the weft yarn through the mechanical action of cooperating feed grippers and pick-up grippers. The weft yarn is transferred approximately in the middle of the shed by means of a spring-loaded device acting on the end of the weft yarn. Alternatively, the opening of the grippers can be controlled from outside the shed by an operating element, the implementation of which in the context of the loom is complex.

[0004] In the weaving of reinforced fabrics (where the weft yarn to be drawn into the shed can be formed from a strip or cylindrical yarn made of carbon fiber, Kevlar fiber, or similar materials), the situation is more concerning than with cotton weft insertion because the weft yarn is fragile, cannot be twisted, and may have variable thickness, smoothness, or width. Conventional weft insertion systems are unsatisfactory and may be unreliable in this field.

[0005] EP-A-1 082 478 discloses a rapier with a clamp comprising a movable claw that can move relative to a fixed claw under the action of an electromagnetic actuator and a spring. Such a method does not allow for precise control of the clamping force applied to the weft yarn, which can lead to damage to the weft yarn. Furthermore, the electromagnetic actuator is bulky and fragile. In this known device, the feed rapier operates in conjunction with the pick-up rapier so that weft yarn transfer occurs in the center of the shed. The feed rapier may damage, cut, or twist the weft yarn due to its oscillating motion. Finally, capturing the weft yarn using a movable clamping portion and a fixed clamping surface is neither reliable nor accurate, particularly because the fixed clamping surface may impact the weft yarn or alter its positioning before clamping.

[0006] On the other hand, as known from EP-A-2 464 768, a gripper head with a clamping device for strip weft yarn material is used, wherein an actuator moves a movable clamping portion relative to a fixed clamping portion. A spring forces the clamp to close, and the actuator must overcome the spring force to function. Therefore, it is difficult to control and monitor the clamping force applied to the weft yarn. Furthermore, the adjustment of the spring force is manual, which is cumbersome.

[0007] Finally, as known from CN-U-203 498 583, a piston is used to drive a screw in order to actuate some of the claws of the chuck assembly. The control of the movement of these claws is imprecise. Summary of the Invention

[0008] The present invention aims to solve the aforementioned problems by providing a novel rapier that is universal because it is compatible with many weft yarn types, including reinforced weft yarns. This rapier allows for efficient control of the clamping force applied to the weft yarn and allows for adjustment of this clamping force. This prevents damage to the weft yarn and allows for the release of different types of weft yarns anywhere along the pull-in path. The invention also provides a lightweight rapier head that allows for high-speed movement of the rapier.

[0009] Therefore, the present invention relates to a rapier for pulling weft yarn from a pickup position into the shed of a loom along a pull-in path, the rapier comprising:

[0010] - A sword head mounted at one end of the sword shaft, the sword head extending along the main longitudinal axis of the sword shaft and driven by a drive along the pull-in path;

[0011] - A clamp for capturing the weft yarn, the clamp being mounted in the rapier head and operable between an open and closed configuration;

[0012] - An actuator mounted on the rapier shaft for actuating the clamp; and

[0013] - A motion conversion mechanism for converting the output motion of the actuator into the opening or closing motion of the clamp.

[0014] According to the invention, the actuator is an electric motor, and the output motion of the motor is a rotation about a rotation axis parallel to the main longitudinal axis of the sword shaft.

[0015] For the purposes of this invention, the warp yarn can be of any known type, having a circular, elliptical, or rectangular cross-section with rounded edges, and can be made of any material, particularly relatively rigid materials such as carbon, glass, ceramics, aramid, or Kevlar fibers. When the warp yarn has a rectangular or elliptical cross-section, it can also be referred to as a ribbon, strip, or belt.

[0016] Because of this invention, the electric motor can be used to transmit precisely defined clamping forces via the motion conversion mechanism. Therefore, the clamp is precisely controlled to efficiently capture weft yarns, even reinforcing or fragile weft yarns, without damaging the yarn. Furthermore, the physical arrangement of the electric motor within the rapier head allows the rapier head to be very compact. This allows the rapier head to move at high speeds within a relatively small shed.

[0017] According to an advantageous alternative aspect of the invention, in any technically permissible construction consideration, such a sword shaft may include one or more of the following features:

[0018] The motion conversion mechanism is configured to operate the clamp from its closed configuration to its open configuration when the output shaft of the electric motor rotates about the rotation axis in a first direction, and to operate the clamp from its open configuration to its closed configuration when the output shaft of the electric motor rotates about the rotation axis in a second direction opposite to the first direction. Due to this aspect of the invention, the rapier clamp operates without a spring, and it can be programmed using dynamic parameters in both directions, i.e., open and closed.

[0019] The motion conversion mechanism includes a slider that can translate between a first longitudinal position and a second longitudinal position along a direction parallel to the main longitudinal axis. The slider is configured to operate the clamp from its closed position to its open position when it moves from its first longitudinal position to its second longitudinal position, and to operate the clamp from its open position to its closed position when it moves from its second longitudinal position to its first longitudinal position. Due to this aspect of the invention, the slider can be integrated into the sword head, and the forward position of the slider facilitates the application of force at the nose of the clamp, i.e., at its forward end.

[0020] The slider comprises a set of two plates extending parallel to the main longitudinal axis on two lateral sides of the axis. Each plate includes a first sliding surface and a second sliding surface, which are separated from each other along the main longitudinal axis and configured to slide along corresponding guide surfaces provided on a frame on the rapier head. Due to this aspect of the invention, the two plates prevent the clamp from oscillating about the longitudinal axis, and the slider can be relatively long, thus being stable and reliable. The two separate sliding surfaces of the plates are compatible with movement within the frame, in which one or more bosses define a rotation axis for a portion of the clamp. The screw-nut sub-assembly of the motion conversion mechanism is efficiently guided by the two plates, which is advantageous for the lifespan of the electric motor.

[0021] The clamp comprises two claws, wherein at least a first claw is hinged relative to the frame of the rapier head about a pivot axis perpendicular to the main longitudinal axis, wherein the first claw extends along the longitudinal axis at least between the pivot axis and a claw tip, the claw tip being configured to engage with the other claw of the clamp to capture the weft yarn to be pulled into the shed, and wherein, preferably, the claw tip is a clamping edge perpendicular to the main longitudinal axis. The hinged claw provides good positioning accuracy, thereby providing good precision in the clamping force applied to the weft yarn. Furthermore, when the claw tip defines the clamping edge, it provides a vertical line of contact across the entire width of the weft yarn, which is reliable for weft yarns of any type and size.

[0022] The clamp includes a first pawl hinged to a frame about a first pivot axis perpendicular to the main longitudinal axis relative to the sword head, and a second pawl hinged to a frame about a second pivot axis perpendicular to the main longitudinal axis relative to the sword head, wherein the first and second pivot axes are parallel and / or overlap. Due to this aspect of the invention, the two pawls move toward each other much faster than if only one pawl were present. Because they can be guided over their entire width, their parallelism can be well controlled.

[0023] The first and second claws extend symmetrically on both sides of the main longitudinal axis, and the motion conversion mechanism applies opposing forces to the first and second claws to pivot them toward or away from each other relative to the main longitudinal axis. Due to this aspect of the invention, the yarn is reliably captured at the pick-up position presenting the weft end and remains reliably clamped during the pull-in process.

[0024] The first claw is provided with a groove and the slider is equipped with a driven member engaging in the groove of the first claw, or the slider is provided with a groove and the first claw is equipped with a driven member engaging in the groove of the slider, and the groove is configured to guide the driven member engaging in the groove and to convert the translational motion of the slider parallel to the main longitudinal axis into the pivoting motion of the first claw. This structure of the rapier provides a reliable mechanical connection between the slider and the claw. The contact area formed between the slider and each claw can be a contact line. Therefore, the movement of the movable claw or each claw is accurate and without torsion. A strong clamping force is not required to ensure efficient capture of the weft yarn. The output torque of the electric motor can be adjusted, which reduces the risk of cutting the weft yarn end.

[0025] - The groove has a curved profile extending between a first end and a second end; when the driven member is at the first end, the clamp is in its open configuration; when the driven member is at the second end, the clamp is in its closed configuration, and the second end of the profile extends a distance measured parallel to the main longitudinal axis, the distance being less than 35%, preferably about 25%, of the distance between the pivot axis and the claw end measured along the main longitudinal axis. Due to this aspect of the invention, the acceleration curves of the movable claws (multiple movable claws) can be adjusted as needed. Accurate and reliable motion can be obtained using relatively long claws, cams, and sliders, allowing for acceleration of the claws' relative motion. Due to this aspect of the invention, the force applied to the claws for closing the clamp is applied close to the claw end to minimize the bending of the claws, and the dynamic response of the motion conversion mechanism is direct and rapid.

[0026] The slider is equipped with a nut integrally or rotatably fixed to the slider, and the electric motor is equipped with a threaded rod engaged in the nut. Alternatively, the electric motor is equipped with a nut integrally or rotatably fixed to the electric motor, and the slider is equipped with a threaded rod engaged in the nut. In both cases, the rotational motion of the electric motor's output shaft is converted into the translational motion of the slider. This screw-nut assembly allows for a reduction in the output motion of the electric motor and possible adjustment of the torque.

[0027] The jib includes: a position encoder for measuring geometric parameters relating to the opening of the clamp, and / or a torque controller for measuring the torque transmitted by the electric motor. The position encoder and / or torque sensor allow adjustment of the clamping force of the jaws based on information collected by the sensors.

[0028] According to another aspect of the invention, the invention also relates to a method for drawing a weft yarn onto a shed on a loom, the loom comprising:

[0029] -Warp yarn transfer unit;

[0030] - Heddle wires used to move the warp yarns in order to form the shed;

[0031] - A shed forming mechanism that causes the heddle wire to move;

[0032] - A weft bobbin, which supplies weft yarn to the loom; and

[0033] - A rapier for pulling the weft yarn from a pickup position into the shed along a pull-in path, the method comprising at least the following steps:

[0034] a) Capture the weft yarn at the pickup location;

[0035] b) Pull the weft yarn along the pull-in path into the shed to a predetermined position;

[0036] c) Release the weft yarn at the predetermined position; and

[0037] d) Remove the rapier from the predetermined position (P3) of the shed.

[0038] According to the invention, the method is carried out using the sword shaft as described above, and at least one of the geometric parameters representing the opening of the clamp and the parameters representing the clamping force is measured during at least one of steps a), b), or d), and the values ​​of the measured parameters are compared with a threshold or the two values ​​of the parameters measured during two different steps are compared with each other.

[0039] Due to the method of the present invention, the presence and thickness of the weft yarn can be checked during the pull-in movement of the rapier. Advantageously, no additional external equipment components (e.g., cameras or sensors) are required to monitor the wet yarn in the enclosed environment of the loom, where the shed is dense, the yarn is fragile, and neither the rapier nor the weft yarn has sufficient visibility for external monitoring.

[0040] According to an advantageous alternative aspect of the invention, and considering any technically permissible construction, such a method may include one or more of the following features:

[0041] The geometric parameters representing the opening of the clamp or the parameters representing the clamping force are respectively: measured by the electric motor as the angular position of the output shaft of the electric motor about the axis of rotation; or measured as physical values ​​proportional to the torque applied to the clamp by the electric motor.

[0042] - In step c), the clamp is placed in its open configuration, and during step d), a sub-step is performed, the sub-step comprising:

[0043] d1) - To move the clamp from its open configuration (Φ5) to its closed configuration, and

[0044] d2) - Measure the geometric parameter (θ) representing the opening of the clamp within the closed configuration.

[0045] and,

[0046] The geometric parameter measured in at least one of steps a), b), or d) and compared with the threshold is the geometric parameter measured at sub-step d2), or

[0047] The two values ​​of the geometric parameter (θ) measured during the two different steps are included in the value measured in sub-step d2).

[0048] - The value of the geometric parameter representing the opening of the fixture, measured during step b), is compared with the value of the same geometric parameter measured during sub-step d1).

[0049] The clamping force applied by the clamp in its closed configuration or the angle between the two jaws of the clamp at the pickup position can be adjusted between two consecutive pickups based on parameters depending on the weft yarn characteristics or based on external parameters, and the clamping force or opening of the clamp is measured by the electric motor during step a). This aspect of the method of the invention allows the action of the clamp on the weft yarn to be adapted to the weft yarn material inserted at each pickup.

[0050] According to another aspect of the invention, the invention also relates to a loom for weaving fabrics using warp yarns and interlaced weft yarns, the loom comprising a warp yarn transfer unit; heddles for moving the warp yarns to form a shed; a shed forming mechanism for moving the heddles; a weft yarn bobbin for supplying weft yarns to the loom; and a rapier for pulling the weft yarns from a pick-up position into the shed along a pull-in path.

[0051] According to this aspect of the invention, the rapier is as described above and includes an embedded control unit that communicates with the control unit of the loom, and the embedded control unit controls the electric motor of the rapier based on data provided by the control unit of the loom. Attached Figure Description

[0052] The invention will be better understood and its other advantages will become more apparent from the following description of two embodiments of the rapier, weaving method, and loom according to the invention. This description is provided by way of example only and is made with reference to the accompanying drawings, wherein:

[0053] - Figure 1 This is a three-dimensional schematic diagram of the loom according to the present invention;

[0054] - Figure 2 for Figure 1 The enlarged view of detail II above, in which the loom's thread has been omitted for simplicity;

[0055] - Figure 3 for Figure 1 and Figure 2A three-dimensional diagram of the rapier of a loom and some of its surrounding components;

[0056] - Figure 4 for Figure 3 A perspective view of one end of the sword shaft on its head side, wherein a portion of the frame of the sword head has been omitted for clarity;

[0057] - Figure 5 This is a partial 3D exploded view of the head of the sword shaft;

[0058] - Figure 6 A three-dimensional view of the rapier head interacting with the weft yarn;

[0059] - Figure 7 A three-dimensional schematic diagram of the forward end of the sword shaft and some of its surrounding components;

[0060] - Figure 8 A side view of a portion of the sword head, with the clamp in a closed configuration;

[0061] - Figure 9 For similar Figure 8 A side view showing the clamp in an open configuration;

[0062] - Figure 10 For similar Figure 9 A side view of the sword shaft according to a second embodiment of the present invention; and

[0063] - Figure 11 This is a schematic diagram of the weaving method of the present invention, showing the change of the opening angle of the clamp over time and the change of the torque applied by the electric motor over time. Detailed Implementation

[0064] Figure 1 The loom 2 shown includes a frame 4 that supports the jacquard machine 6 and several control cabinets 8 above the weaving machine 10, which is fixed to the ground G. The frame 4 has multiple supports 12, also fixed to the ground, which together support a platform 14, on which the jacquard machine 6 and control cabinets 8 are located.

[0065] The through yarn 16, made of heddle yarn 17 and strands not shown, can move vertically to form the shed S shown at the level of the weaving machine 10 with the warp yarn 18 from the warp beam frame (not shown).

[0066] The alternating vertical movement of the through wire and heddle wire 17 Figure 1 The double arrow A1 represents the middle.

[0067] The rapier 20 is used to insert the weft yarn 34 into the shed to weave the fabric 22. Figures 1 to 3In the diagram, double arrow A2 represents the alternating horizontal movement of the rapier 20 along the weft insertion axis Y20 as it is guided by the track 201 of the rapier unit 200. The rapier unit 200 forms a weft insertion mechanism and also includes a drive 203 for reciprocating the rapier 20 along the weft insertion axis Y20.

[0068] exist Figure 2 In the diagram, arrow A3 indicates the unidirectional movement of the woven fabric 22 toward the take-up carriage 24.

[0069] After each pick-up, the weft yarn 34 is beaten into the fabric 22 using the reed 23. Figure 2 In the diagram, the double arrow A23 represents the striking motion of the reed.

[0070] The weft yarn 34 is unwound from the bobbin 26 located next to the weaving machine 10 and supplied to the rapier 20 via a weft selector 28 fed from the bobbin through a compensator 30, which is known in itself and designed to prevent wobbling during the supply of the weft yarn. The compensator 30 ensures a substantially constant tension on the weft yarn 34 exiting the compensator.

[0071] In the example shown in the attached diagram, six bobbins 26 are mounted on a support bracket 32 ​​fixed to the ground G, next to the weft selector 28 and the compensator 30. Weft yarns from up to twelve bobbins 26 can be fed to the weft selector 28. The number of bobbins 26 can be increased to match the different numbers of weft yarns to be used in the loom 2.

[0072] In this example, the warp yarns 18 are made of polyester, polyamide, or other relatively inexpensive thermoplastic materials. Alternatively, these warp yarns can be made of glass, carbon, or another more refined material to produce, for example, three-dimensional technical multilayer fabrics for propeller blades, or two-dimensional multilayer fabrics that can be cut and assembled together by a lay-up process, for example, to form technical components for automobiles.

[0073] The weft yarn 34 is made of reinforced plastic or fibers such as carbon, Kevlar, ceramic, aramid, or glass. As mentioned above, these yarns can have circular, elliptical, rectangular cross-sections, or generally rectangular cross-sections with rounded edges. They can be formed into circular yarns, strips, ribbons, or satin ribbons with widths between 0.014 mm and 5 mm.

[0074] The sword shaft 20 includes a sword shaft 202, which is made of metal and extends the main longitudinal axis A20 of the sword shaft 20. The shaft 202 is provided with a series of teeth that together form a rack 202a that meshes with the drive wheel 203a of the drive member 203. Therefore, as... Figure 3As shown by arrow A203, the rotation of the drive wheel 203a around the vertical axis Z203 causes the rapier 20 to shift along the weft insertion axis Y20, as shown by double arrow A2.

[0075] The rapier body 204 is rigidly mounted to one end of the rapier shaft 202 via an assembly mechanism 205 comprising a bracket 205a and screws 205b. In this example, the rapier body 204 includes an armature 204a formed of a rigid metal plate and an adapter block 204b rigidly mounted on the armature. The armature is elongated, with its longest dimension parallel to the main longitudinal axis A20. Therefore, the rapier body 204 is also elongated and extends along this main longitudinal axis. Due to the rigid connection between components 204 and 202, the rapier body 204 is driven by the rapier shaft 202 along the pull-in axis Y20 via a drive wheel 203a.

[0076] The cover, not shown, belongs to the sword body 204 and is configured for mounting on parts 204a and 204b.

[0077] The rapier shaft 202 is made of a rigid metal component. Alternatively, the rapier shaft can be replaced by a rapier belt made of semi-rigid plastic, which is also provided with a rack configured to engage with the drive wheel 203a.

[0078] An electronic control unit (ECU) 207 is embedded in the rapier 20, or more precisely, mounted on the rapier body 204. An electric motor 208 is mounted on an adapter block 204b, wherein the output shaft 208a of the electric motor is oriented relative to the ECU 207. A208 represents the longitudinal axis of the output shaft 208a, which is also the axis of rotation of the output shaft. To illustrate the output shaft 208a, in... Figure 5 The motor 208 is shown as offset from the adapter block 204b along the longitudinal axis A20. Its normal position is as follows: Figure 4 and Figure 7 As shown in the image.

[0079] The longitudinal axis A208 is aligned with the longitudinal axis A20. In other words, the output motion of the electric motor 208 is a rotational motion about axis A208, which is parallel to and overlaps with the longitudinal axis A20. Alternatively, the longitudinal axis A208 of the output shaft 208a and the main longitudinal axis A20 of the rapier 20 can be offset and parallel. In this case, the output motion of the motor 28 is a rotation about axis A208, which is parallel to but does not overlap with the main longitudinal axis A20 of the rapier 20.

[0080] In fact, the electric motor 208 is a servo motor, or more precisely, a brushless DC motor.

[0081] ECU 207 and electric motor 208 are connected to each other via wire 209. Position encoder 210 is integrated into electric motor 208 and allows measurement of the angular position of output shaft 208a about rotation axis A208, i.e., the opening of clamp 320, or its rotational speed. Alternatively, the position encoder can be assembled together with electric motor 208. At the rear of position encoder 210, a torque sensor 212 is also included in scissor 20, and the torque sensor measures the torque T representing the torque transmitted to motor 208. mot The instantaneous value of the current. Alternatively, a torque controller is included in ECU 207, and the torque controller can detect the mechanical torque of motor 208. Wire 209 allows power to be supplied to electric motor 208 and transmits data from encoder 210 to ECU 207.

[0082] The ECU 207 is connected to the cable connector 216 via a corresponding wire 214. Between the ECU and the cable connector 216, the wire 214 circulates in the rail 201 and the cable drag-chain 220.

[0083] Cable connector 216 is connected to power supply 224 via first power line 222, which provides power for actuating electric motor 208 via control unit 207. Cable connector 216 is also connected to main control unit or main ECU 82 via data line or bus 226, which in this example is mounted in one of the cabinets 8, such as... Figure 1 It is visible in the text.

[0084] The main ECU 82 communicates with a memory 84, in which a program P is loaded to guide different components of the loom 2 according to a predetermined pattern.

[0085] Alternatively, memory 84 can be part of the main ECU 82.

[0086] The main ECU 82 is connected to the controlled components of the loom 2, such as the drive unit 203, the reed 23, and the take-up bracket 24, via the corresponding bus 228.

[0087] like Figure 3 As indicated by the double arrows, data lines or buses 226 and 228 allow bidirectional communication, enabling the main ECU 82 to guide the corresponding parts of the device according to the selected program P and obtain feedback on the actual operating conditions and parameters of these parts of the device.

[0088] Specifically, the main ECU 82 provides certain data to the insert in the ECU 207 via data line or bus 226 and wire 214 for controlling the electric motor 208 according to the selected program P and according to the position of the heddle wire 17.

[0089] The sword head 206 is mounted at one end of the sword shaft 20 and belongs to the sword shaft. The sword body is inserted between the sword shaft 202 and the sword head 206 along the main longitudinal axis A20.

[0090] The structure of the rapier head 206 will now be described.

[0091] The rapier head 206 includes a slider 260 made of two rigid plates 262 and 264 and a nut 266, all preferably made of a synthetic material such as plastic (particularly PEEK). Each plate 262 or 264 is provided with a beveled hole 268 for receiving a corresponding screw 270 threaded into a corresponding threaded hole 272 of the nut 266. This allows the slider 260 to be formed by fixing the two plates 262 and 264 relative to the axis A20 to the nut 266. With this configuration, the slider 260 is rigid and can move reliably in a direction parallel to the axis A20, as explained below.

[0092] Each plate 262 or 264 is also provided with two cylindrical holes 274, each of which receives a cam cylinder 276. In total, the rapier head 206 comprises four cam cylinders, with two cam cylinders on each plate 262 or 264. The two cam cylinders 276 mounted in the upper cylindrical holes 274 of the two plates 262 and 264 are aligned along a first axis A276. Similarly, the two cam cylinders 276 mounted in the lower cylindrical holes 274 of the two plates 262 and 264 are aligned along a second axis A'276. Axis axes A276 and A'276 are perpendicular to the main longitudinal axis A20 and offset in a direction perpendicular to that axis (i.e., vertical in this case). A camshaft 278 extends between the pairs of cam cylinders 276 aligned along the same axis A276 or A'276.

[0093] like Figure 5 As can be seen, each camshaft 278 has a central portion with a relatively large diameter and two ends with a reduced diameter, the two ends being adapted to be introduced into the central bore of the cam cylinder 276.

[0094] Boards 262 and 264 are identical. Board 262 is described below, and its description also applies to board 264.

[0095] Plate 262 is shaped into an I-shape, wherein the central segment 262a is parallel to axis A20 and the two end segments 262b and 262c are perpendicular to the central segment 262a and parallel to each other.

[0096] The rapier 20 is designed to pick up the weft yarn 34 at pick-up position P1 and, during its movement ending at a withdrawal position P2 located on the other side of the shed, pull the weft yarn into the shed from outside the shed. A weft yarn insertion path is defined between these positions P1 and P2 along the pull-in axis Y20. The rapier 20 can release the weft yarn 34 at any release position P3 selected between positions P1 and P2 along the pull-in axis Y20.

[0097] When the rapier head moves from the withdrawn position P2 to the pick-up position P1 along the pull-in axis Y20, the front side of the rapier 20 is defined as the side of the rapier 20 oriented towards the weft yarn 34 to be picked up. Specifically, the rapier head 206 is mounted on the front side of the rapier body 204, which is mounted on the front side of the rapier shaft 202.

[0098] The back of the sword shaft is opposite to its front.

[0099] Under this definition, end segment 262b is the front end segment of plate 262 and end segment 262c is the rear end segment of plate 262. A beveled hole 268 is drilled through the rear end segment 262c and a cylindrical hole 274 is drilled through the front end segment 262b.

[0100] Between the front end segment 262b and the rear end segment 262c, and on either side of the central segment 262a, plate 262 defines two longitudinal slots 280, the maximum size of which is parallel to the longitudinal axis A20. This corresponds to the I-shaped shape of plate 262.

[0101] Nut 266 includes an internally threaded portion 282 that accommodates a threaded mandrel 284. This mandrel is rapidly rotated about a rotation axis A208 and via a threaded collar 286 together with the output shaft 208a of the servo motor 208. Due to the screw and nut assembly formed by components 282 and 284, the rotational output motion of the servo motor shaft 208a about axis A208 is converted into a translational motion of the slider 260 along the longitudinal axis A20.

[0102] 279 and 281 represent the end surfaces of the front end segment 262b and the rear end segment 262c, respectively. These end surfaces are parallel to the longitudinal axis A20 and perpendicular to the longest dimension of each end segment 262b and 262c. In the configuration shown in the figures, these surfaces 279 and 281 form the upper and lower surfaces of the end segments 262b and 262c.

[0103] On the other hand, the sword head 206 includes a frame 290 formed by a first housing 292 and a second housing 294. For clarity, in Figure 4 , Figure 5 as well as Figures 7 to 9 The outer shell is omitted in section 292.

[0104] Housings 292 and 294 are identical. Housing 294 is described below, and its description also applies to housing 292.

[0105] The housing 294 is made of a metal material such as light aluminum and has a concave shape, wherein its concave surface is oriented toward the slider 260 so that the slider 260 and any components located between the two plates 262 and 264 can be accommodated within the frame formed by the housings 292 and 294.

[0106] The housing 294 is provided with two rear holes 296 for two screws 298 to pass through, the two screws engaging in corresponding threaded holes 300 in the adapter block 204a. This allows the housing 294 to be securely attached to one side of the adapter block 204a. Figure 5 (Not visible in the middle). Therefore, frame 290 and adapter block 204 are fixed to each other along longitudinal axis A20.

[0107] The housing 294 is also provided with two blind holes 302, which are configured to receive part of a pin 304 that also engages with a similar blind hole in the housing 292. The two pins 304 engaged in the four blind holes 302 allow the two housings 292 and 294 of the frame 290 to be centered relative to each other.

[0108] The housing 294 also includes two internal bosses 306, each boss 306 defining a through hole 308 that can accommodate the end of a cylindrical sleeve 310, the cylindrical sleeve forming a planar bearing for a clamp-jaw, as explained below.

[0109] Each end of each sleeve 310 has an internal thread for receiving the end of a support screw 302 inserted from the outside of housing 292 or 294 into a corresponding through hole 308 drilled in the housing. Thus, once the two housings are assembled together to form frame 290, the two sleeves are securely held and precisely positioned within the internal space defined by the two walls of the two housings parallel to the plates 262 and 264.

[0110] like Figure 5As shown, the housing 294 defines four guide surfaces S294, which are parallel to the axis A20 and configured to provide sliding contact with the lateral surfaces 279 and 281 of the receiving plates 262 and 264. These four guide surfaces S294 are located on the inner sides of the upper and lower walls of the housing. Figure 5 In the diagram, the surfaces S294 provided on the upper wall of the housing 294 are indicated by dashed lines because they are visible through the upper wall.

[0111] Surface S294 is divided into a front surface S294 and a rear surface S294. The front surface is configured to mate with the front lateral surface 279, and the rear surface is configured to mate with the rear lateral surfaces 281 of the two plates 262 and 264. The contact between the metal surface S294 and the two plates 262 and 264 made of PEEK is improved in terms of smoothness and lifespan.

[0112] When plates 262 and 264 are mounted within housings 292 and 294 at locations where rear holes 296 are provided, the slots 280 defined by plates 262 and 264 accommodate bosses 306. Due to these slots, bosses 306 do not impede the reciprocating movement of plates 262 and 264 within the frame 290.

[0113] The two claws 322 and 324 together form a clamp 320 that is embedded in the head 306 of the rapier. In the configuration shown in the figure, claw 322 can be identified as the upper claw and claw 324 can be identified as the lower claw.

[0114] The upper jaw 322 is hinged about axis A322, which is defined by the upper sleeve 310, and is held in place within the frame 290 via upper through-holes 308 in the two housings 292 and 294. Similarly, the lower jaw 324 is hinged about a lower axis A324, which is defined as the central axis of the lower sleeve 310, and is held in place within the frame 290 via a lower through-hole 308.

[0115] In order to allow for such an installation that enables the claws to rotate about axes A322 and A324, each claw 322 or 324 is provided with a through hole 326 near its rear end.

[0116] On the other hand, each pawl 322 or 324 is provided with a cam groove 328 for receiving one of the camshafts 278. Therefore, each camshaft 278 forms a follower that engages in the cam groove 328 of the pawl 322 or 324. Each camshaft 278 forms a linear contact area between the slider 260 and the groove 328 in which the camshaft is inserted. Alternatively, a point contact can be formed between the slider 260 and the groove 328, but this point contact is less advantageous.

[0117] Components 260 to 328 allow two claws 322 and 324 to be hinged about two axes A322 and A324 about a longitudinal axis A20 perpendicular to the shank 20, and the position of the two claws about these axes is controlled by the translational movement of the slider 260 along the longitudinal axis.

[0118] In practice, components 260 to 328 together form a motion conversion mechanism for converting the output rotational motion of the output shaft 228a of the servo motor 208 about the rotation axis A208 into relative motion between two jaws 322 and 324. More precisely, the motion conversion mechanism 260 to 328 applies opposing forces via camshaft 278 to the first jaw 322 and the second jaw 324 to pivot the first and second jaws toward or away from each other, as from Figure 8 and Figure 9 The comparison yields the following result. Camshaft 278 forms the output component of the motion conversion mechanism to operate the first and second jaws 322 and 324 of clamp 320 in their relative movements of opening or closing. In practice, motion conversion mechanisms 260 to 328 are configured such that, around the rotation axis A208, the output shaft 208a of the electric motor... Figure 5 When the clamp 320 is rotated in the first direction indicated by arrow R1, it opens, i.e., it operates the clamp from its closed configuration to its open configuration. Conversely, the motion conversion mechanism is configured such that the output shaft 208a of the electric motor rotates about the axis of rotation A208 in a direction opposite to the first direction. Figure 5 The clamp closes when rotated in the second direction, as indicated by arrow R2, i.e., when the clamp is operated from its open position to its closed position.

[0119] 322a represents the leading edge of the upper claw 322. This leading edge is straight and parallel to axes A322 and A324, and therefore perpendicular to axis A20. Similarly, the leading edge 324a of the lower claw 324 is straight and parallel to axes A322 and A324, and perpendicular to axis A20.

[0120] Due to the orientation of the two parallel edges 322a and 324a, and the symmetrical shape of the two claws 322 and 324 relative to the longitudinal axis A20, linear contact between the two edges and the weft yarn on the upper and lower sides of the weft yarn 34 can be achieved, which avoids damage to the weft yarn or reduces the risk of damaging the yarn.

[0121] For this purpose, a non-friction coating can be applied to the two edges 322a and 324a, or the surface of the claws can be sandblasted at the level of these edges. For example, the coating can be made of copper, zinc, plastic, or rubber.

[0122] Rapier unit 200 controls the oscillating motion of rapier 20 along the pull-in axis, wherein rapier head 206 follows a pull-in path between pick-up position P1 and withdrawal position P2, the pick-up position being adjacent to the receiving basket 29 near weft selector 28, and the withdrawal position being located on the other side of the shed. Rapier 20 is guided through the shed by rod 202, which floats above the warp yarns 18 of the shed. Clamp 320 located at the nose of rapier 20 (i.e., the forward end of rapier head 206) captures the weft yarn 34 from the weft selector 28 on one side of the loom and inserts the weft yarn into the shed by pulling it from the pick-up position to a predetermined position P3 for releasing the weft yarn. As described above, the predetermined position P3 can be located at any point between positions P1 and P2 along the pull-in axis Y20. Once the weft yarn 34 has been released at position P3, the rapier 20 withdraws the rapier head from the shed into the withdrawal position P2 by bringing the rapier head 206 to the side of the loom opposite to articles 28 and 29.

[0123] For example in Figure 6 As can be seen, the overall shape of the rapier head 206, as defined by the frame 290, results in the rapier head 206 having an overall rectangular cross-section perpendicular to the longitudinal axis A20 and a beveled shape at its forward-facing end or nose oriented toward the weft selector 28 and basket 29. Figure 6 As can be seen, the clamp 320 can capture the weft yarn 34 through the opening 291 between the two housings 292 and 294, which is defined at the front end of the frame 290.

[0124] Each claw 322 or 324 is provided with a relief hole 329, which reduces the inertia of the claw rotating about the corresponding axis A322 or A324.

[0125] Along a direction perpendicular to axes A322, A324 and A20, axes A322 and A324 are separated by a distance d, which in this example is vertical and is set between 5 mm and 15 mm, preferably equal to about 9 mm.

[0126] As in Figure 6 as well as Figures 7 to 9 As can be seen, the front ends of claws 322 and 324 converge towards the main longitudinal axis A20, so that when the rapier head moves forward from position P2 to position P1, the claws do not risk interfering with the warp yarns 18 of the shed. Moreover, the clamp 320 can remain closed, thereby reducing this risk.

[0127] Because each claw 322 or 324 is precisely guided by a sliding bearing formed by its through-hole 326 and the corresponding sleeve 310 over its entire width measured parallel to axis A322 or A324, rotational and linear play between the claw and its surroundings can be reduced. The parallelism and precision of the contact lines between edges 322a and 322b and the weft yarn are precisely defined, which is important for capturing fine weft yarns and thin strips, such as 3K, 6K, or 12K weft yarns.

[0128] In particular, clamp 320 is especially suitable for capturing weft yarns in the form of strips, ribbons, or satin ribbons having a rectangular, near-rectangular, circular, or elliptical cross-section, the strips, ribbons, or satin ribbons having a width between 0.014 mm and 2 cm and a thickness between 0.014 mm and 5 mm. These ranges are not limiting.

[0129] The bidirectional linear motion of the slider 260 along the longitudinal axis A20 of the spar is transformed into a bidirectional nonlinear motion by the cooperation of the camshaft 278 and the cam groove 328. In this example, the bidirectional nonlinear motion is a rotation about the axes A322 and A324 of the sleeve 310.

[0130] More specifically, the shape of the cam groove 328 defines the amplitude and speed of the rotational motion of the claws 322 and 324.

[0131] As from Figure 8 The groove 328 of the upper claw 322, which is more clearly visible, has a hook shape with two straight branches, namely a front branch 328a and a rear branch 328b, which converge rearward toward the main longitudinal axis A20. The rear branch 328b converges toward the longitudinal axis A20 faster than the front branch 328a. α represents the angle between the centerline of the front branch 328a and the main longitudinal axis A20, and β represents the angle between the centerline of the rear branch 328b and the same axis A20. Angle β is greater than angle α, which means that the rear branch 328b is more inclined or steeper relative to the axis A20 than the front branch 328a. The geometry of branches 328a and 328b determines the stroke, dynamics, and intensity of the force applied to the weft yarn by the clamp 320. The opening or closing motion is slower through the engagement sub-stage of the driven member 278 with branch 328a compared to the engagement sub-stage of the driven member 278 with branch 328b.

[0132] The diameter of the main part of each camshaft or follower 278 is selected to be as close as possible to the perpendicular to the axis of rotation. Figure 8 The lateral dimension of the cam groove 328 is measured by the plane of the camshaft 278 and the center lines of branches 328a and 328b. This limits the clearance between the camshaft 278 and the cam groove 328. In fact, this clearance is only a fraction of a millimeter, making the drive of the jaws 322 and 324 around axes A322 and A324 accurate and the dynamic response of the clamp 320 rapid. Moreover, a coating can be applied to these cam grooves 328 to optimize the rolling of the camshaft and the life of the mechanism. For example, the coating can be copper or zinc.

[0133] 328c defines the rearward end of the cam groove 328, which is closer to the corresponding pivot axis A322 or A324 than the rest of the cam groove. When the clamp 320 is in its position as... Figure 9 In the open configuration shown, the follower formed by the camshaft 278 is located in the rearward end. Similarly, 328d represents the forward end of the cam groove 328 when the clamp 320 is in its position as shown in the diagram. Figure 8 In the closed configuration shown, the corresponding driven member or camshaft 278 is located at the forward end.

[0134] When the clamp is in Figure 8 In the closed position, L320 represents the length of the pawl 322 or 324 measured parallel to the longitudinal axis A20 between its pivot axis A322 or A324 and its forward edge 322a or 324a. d1 represents the distance measured parallel to the longitudinal axis A20 between the pivot axis A322 or A324 of the pawl and the rearward end 328c of the corresponding cam groove 328. The ratio of d1 / L320 is between 0.4 and 0.6, preferably equal to about 0.5. d2 represents the distance measured parallel to the longitudinal axis A20 between the pivot axis A322 or A324 and the forward end 328d of the corresponding cam groove 328. The ratio of d2 / L320 is between 0.65 and 0.85, preferably equal to about 0.75. In other words, the distance d3 measured between the forward end 328d of claw 322 or 324 and the front edge 322a or 324a is less than 35%, preferably about 25%, of the length L320. The following equation applies:

[0135] d3 / L320≤0.35(Equation 1)

[0136] The position encoder 210 can be incremental. It may include a disk rotatably fixed to the rotor of the servo motor 208, the disk being provided with angular graduations used as a scale. On the other hand, due to the accuracy and reversibility of the motion transmission between the output shaft 208a on one side and the jaws 322 and 324 on the other side, the angular position of the rotor of the servo motor 208 (which is detected by the position encoder 210) can be regarded as a geometric parameter representing the angular position of the gripper, and in particular as a geometric parameter representing the angular position of the jaws 322 and 324 about their respective pivot axes A322 and A324. This allows the distance d4 between the jaw edges 322a and 324a, measured parallel to the distance d, to be estimated after calibration and taking into account the profile of the slot 328.

[0137] The embedded ECU 207 performs closed-loop control, as is well known in control electronics. This control unit receives a setpoint signal from the main ECU 82 and compares it with the current position of the motor shaft 208a, such as that provided by the position encoder 210. The embedded ECU 207 then determines possible positional offsets and reduces these offsets by sending corresponding commands to the servo motor 208.

[0138] Therefore, the opening range of the clamp 320 can be precisely controlled specifically based on the shape and material of the weft yarn 34 to be captured at the pickup position P1.

[0139] Similarly, the position encoder 210 allows the pawls to know their relative speed of movement, which is also controlled by the embedded ECU 207 that performs closed-loop control.

[0140] The rapier clamp 320 can also be controlled based on the torque transmitted by the electric motor 8. After calibration, the torque sensed by the torque sensor 212 represents the clamping force applied by the claws 322 and 324 when they clamp the weft yarn. The sensed torque can be set and compared with a setpoint value. Moreover, the sensed torque can be compared with a limit value to ensure that it does not exceed the limit value so as not to damage the weft yarn during clamping.

[0141] Considering that the weft yarn may change between two consecutive picks during the weaving process performed on loom 2, setpoint parameters regarding position, shift speed, and / or torque applied to servo motor 208 by ECU 207 can be adjusted between two consecutive picks based on parameters depending on the weft yarn characteristics (such as its cross-section, its shape, its thickness, or its material). This control over the applied torque and / or position / speed results in control over the clamping force applied by the clamps. External parameters, such as the number of picks per minute, the temperature or humidity in the workshop, or parameters manually set by the weaver, can also be considered for adjusting the clamping force between picks.

[0142] When the weaving method according to the invention is implemented on loom 2, the method for distributing weft yarns into the fabric developed in EP-A-3121 317 can be used. However, this is not mandatory, and different weaving methods are permissible when the loom of the invention uses the rapier 20 of the invention.

[0143] For each pickup, memory 84 stores weft parameters, such as weft type, weft thickness, weft length, weft width, weft position along the pull-in axis, coefficient of friction between the weft and the claw, etc.

[0144] The main ECU 82 determines the value or range of values ​​for the clamping parameters used for the rapier head 206 based on the rapier position along the pull-in axis Y20 and / or based on the weaving cycle. This value can be:

[0145] -When the clamp is closed on the weft yarn at the pickup position P1, the angular positions of claws 322 and 324 are...

[0146] -When the rapier head is between positions P1 and P3, pulling the weft yarn 34 into the shed, the angle position of the claw...

[0147] - When the rapier head reaches the release position P3, the angle position of the claw;

[0148] -etc.

[0149] Embedded ECU 207 collaborates with main ECU 82 to control the continuous operation of servo motor 208, wherein the main ECU controls drive 203 for moving rapier 20 along pull-in axis Y20 and jacquard loom 6 for forming the shed set by program P selected for weaving. Control units 82 and 207 continuously exchange information via data line or bus 226. Furthermore, ECU 207 may optionally communicate with a program library to store and analyze data during the weaving process, build statistics, and identify any deviations.

[0150] exist Figure 10 In the second embodiment of the invention shown, the elements of the sword shaft similar to those in the first embodiment have the same reference numerals and operate in the same manner. Hereinafter, only the differences from the first embodiment will be described in detail.

[0151] In this second embodiment, the two jaws 322 and 324 of the clamp are hinged relative to the sword head frame represented by the housing 294 along a common axis A320. In this embodiment, the common axis A320 serves as the axes A322 and A324 of the first embodiment (which overlap here). The two jaws are not guided along axis A320 over the entire width of their sliding bearings, but each jaw is guided by half of the sliding bearing, which in this embodiment is common to both jaws.

[0152] As in the first embodiment, the camshaft 278 moves parallel to the longitudinal axis A20 and engages in the cam groove 328, which allows the guide pawls 322 and 324 to pivot about the common axis A320.

[0153] Applicable to both embodiments Figure 11 In the representation, it is assumed that the movement of the rapier 206, which moves its head 206 from the withdrawn position P2 to the pick-up position P1, begins at time t0. During the first phase Φ1, the rapier 20 moves forward along the pull-in axis toward the pick-up position P1. The clamp 320 remains closed to avoid interfering with the shed, and the opening angle θ of the claws 322 and 324 is set to zero. Figure 8 In its design, the opening angle θ is set to zero. The servo motor 208 applies no torque. In other words, the motor torque T... mot It equals zero.

[0154] When the sword head is about to reach the pickup position P1 at time t1, the pawl begins to open until the opening angle θ of the clamp 320 reaches the given maximum value θ. M The maximum value θ M This occurs at time t2 when the rapier is in the pickup position P1. Between times t1 and t2, the torque applied by the motor increases rapidly and then remains constant at a value T. m1 Then it decreases back to zero. When the claw is in the fully open position, the electric motor 208 does not apply torque between times t2 and t3. The opening of the claw occurs in the second stage Φ2 between times t1 and t3.

[0155] At time t3, the third stage Φ3 begins, in which clamp 20 captures the weft yarn 34. For this purpose, the opening angle θ between claws 322 and 324 decreases to the intermediate value θ. i The intermediate value is reached at time t4. To change the angle θ from the value θ... M Reduce to value θ i The torque applied by the servo motor 208 becomes negative between times t3 and t4 and takes a second value T. m2 The term "negative" means that along the torque T... m1 Apply torque T in the opposite directionm2 In other words, the servo motor 208 actuates the clamp 20 in opposite directions by rotating in one direction and the opposite direction, as indicated by arrows R1 and R2. At time t4, the clamp is closed around the weft yarn 34, where the value θ is equal to... i The angle θ is strictly greater than zero to avoid cutting or damaging the weft yarn. i The value is one of the setting parameters provided by the embedded ECU 207 to the electric motor 208 and controlled via the encoder 210. From time t4 until another time t5, the angle θ remains at the value θ. i Furthermore, the torque applied by the servo motor 208 remains at zero and the highest absolute value T applied between times t3 and t4. m2 An intermediate value T between mi The non-zero torque T mi It is necessary to keep the weft yarn 34 clamped between the claw edges 322a and 324a during the pull-in motion between positions P1 and P3. During this pull-in motion, the clamp 320 must overcome the frictional force of the weft yarn 34 in the devices 28 and 30, which tends to resist the weft yarn in the direction opposite to the pull-in direction.

[0156] At time t5, the rapier 20 begins to open the clamp 320 so that angle θ returns to its maximum value θ from time t6 to time t7. M In this fourth stage Φ4, which occurs between times t5 and t7, the weft yarn 34 is released in the release position P3, and the servo motor 208 applies torque T in the same direction as between times t1 and t2. m1 This allows the clamp to be opened. Between times t6 and t7, clamp 320 remains open, angle θ remains constant, and no torque is applied.

[0157] In the fifth stage Φ5, which begins at time t7 and ends at time t8, the clamp is closed again by making the angle θ zero, which is achieved by applying torque in the same direction as between times t3 and t4. Then, the torque and angle θ remain constant until the rapier reaches the withdrawal position P2, at which the process begins again.

[0158] For example, assuming the angular orientation of the output shaft 208a around axis A208 represents angle θ, then during at least the third stage Φ3, the geometric parameters representing the opening of the clamp 320, i.e., the geometric parameters of angle θ, are measured by the electric motor. Therefore, if angle θ is between t4 and t5, the torque T mi If the reduction exceeds a given limit, such as 20%, under the influence of the rapier, it can be assumed that the weft yarn has been lost between positions P1 and P3.

[0159] In fact, when the angle θ is changed from the value θ M As the clamp moves back toward its closed configuration by decreasing to zero, the geometric parameters representing the opening of clamp 320 are measured by an electric motor at least during the fifth stage Φ5. This allows for checking whether the weft yarn has been correctly released at position P3.

[0160] Specifically, the angle θ measured during stage Φ3 can be compared with the angle θ measured during stage Φ5. This allows for checking whether stage Φ4 has been correctly implemented at the correct position P3 along the pull-in axis Y20. Specifically, it is determined whether these values ​​are the same or different. "The same" means that the values ​​differ by less than 5%. If the values ​​are different, the process is considered to be operating normally. If the values ​​are the same, the process is considered defective and an alarm is triggered.

[0161] Alternatively, the value of the angle θ measured during stage Φ5 can be compared with a previously preset threshold θ. T A comparison is made. The previously preset threshold θ can be determined based on the thickness of the weft yarn. T The thickness of the weft yarn can be provided manually or by program P. Alternatively, the previously preset threshold θ can be determined by a calibration step performed at the start of the weaving process using the current weft yarn. T .

[0162] The value of angle θ measured during phase Φ5 and the threshold θ T During the comparison step, it is determined whether these values ​​are the same. Same means that the values ​​differ by less than 5%. If the values ​​are the same, the process is considered to be operating normally. If the values ​​are different, the process is considered defective and an alarm is triggered.

[0163] Additionally, assuming the motor torque T mot The clamping force is represented by a parameter, namely the motor torque T transmitted by the motor 208, which is measured by the torque sensor 212 at least during the third stage Φ3 and the fifth stage Φ5. mot .

[0164] The motor torque T will be measured between time t4 and t5. mot The value of T is equal to T mi The first preset threshold T T Compare the threshold T. T Alternatively, the threshold T can be determined based on the thickness of the weft yarn, which can be provided manually or by program P. Alternatively, the preset threshold T can be determined by a calibration step performed at the start of the weaving process using the current weft yarn. T .

[0165] Similarly, the motor torque T measured at time t8 will be... mot The second preset threshold T equal to 0 T Compare them.

[0166] Alternatively, two values ​​of motor torque measured during two different steps of the pull-in method can be compared.

[0167] Motor torque T measured during phases Φ3 and Φ5 mot The value of the threshold T T During the comparison step, it is determined whether these values ​​are the same. Same means that the values ​​differ by less than 5%. If the values ​​are the same, the process is considered to be operating normally. If the values ​​are different, the process is considered defective and an alarm is triggered.

[0168] Alternatively, two values ​​of motor torque measured during two different steps of the pull-in method can be compared.

[0169] When using threshold θ T or T T At that time, the threshold is stored in the main ECU 82 of the loom. The measured geometric parameters representing the opening of the clamp or the measured parameters representing the clamping force are stored in the main ECU 82, specifically in the memory 84.

[0170] Preferably, the measured parameter θ or T mot With the corresponding threshold θ T or T T The comparison occurs within the main ECU 82. Similarly, the parameters θ or T measured at two different steps... mot The comparison between the values ​​also occurs within the main ECU 82 to detect abnormal gaps. If the comparison result meets the criteria for stopping the loom, the main ECU 82 triggers a signal.

[0171] Alternatively, the embedded controller ECU 207 of the rapier 20 stores continuous measurements, different thresholds, compares the continuous values ​​with each other or with the thresholds, and / or triggers a signal if the result of the comparison meets the criteria for stopping the loom.

[0172] Preferably, as described above, the parameter representing the clamping force, i.e., the motor torque T, is measured via a physical value, preferably via the instantaneous value of the current of the electric motor 208. mot The physical value is proportional to the torque applied to the fixture by the servo motor.

[0173] Furthermore, the opening of the fixture and / or the torque transmitted by the servo motor can be monitored and / or stored during multiple pick-ups, allowing for control of process deviations and the creation of historical data tables, which are then stored in a local file. For example, monitoring the opening of fixture 320 and / or the torque transmitted by servo motor 208 also allows for monitoring the accumulation of debris (such as dust in the rapier head 206) and the wear of fixture 320, which allows for the detection of system drift and the scheduling of appropriate maintenance operations.

[0174] Considering the current weft yarn to be pulled in and released into the shed, and according to the selected program P, partially or completely adjust the rotor's angular position, the applied torque, and the timing of pickup. Furthermore, as described below, certain modifications can be made to the rapier, loom, and method of the present invention.

[0175] The continuity of stages Φ1 to Φ5 indicates that the servo motor 208 and the associated motion conversion mechanisms 260 to 312 allow for precise control of the fixture 320 and even the detection of undesirable conditions by controlling the angular position of the rotor of the servo motor 208 and / or the torque applied by the servo motor. An undesirable condition is detected when the result of measuring the rotor's angular position and / or the torque applied by the servo motor does not reach a threshold, which is set before the weaving operation or preferably by measuring the rotor's angular position and / or the torque applied by the servo motor in a previous step. An undesirable condition is detected when the variation in the result of measuring the rotor's angular position and / or the torque applied by the servo motor does not exceed a given relative limit.

[0176] Furthermore, the opening of the measuring fixture 320 corresponding to the angle θ and / or the torque T transmitted by the servo motor 208... mot This occurs at different steps of pulling in the weft yarn in order to verify that one or more different steps of picking are being performed correctly.

[0177] According to an embodiment of the invention (not shown), one of the jaws of the clamp may be fixed, and the other jaw may be guided by a slider, as explained above with respect to the two jaws of the first and second embodiments. Alternatively, the jaws may be asymmetrical.

[0178] The design of the slider can differ from that shown in the attached figure, and another type of mechanical component can be used to convert the translational motion of the slider into the angular motion of one or more claws.

[0179] Inside the rotary bearing formed by the sleeve 310 in the hole 310, other types of bearings, especially high-precision linear bearings, can be considered.

[0180] Alternatively, plates 262 and 264 can be made into a single part with nut 266. In this case, the linear arm of the nut, which replaces plates 262 and 264, can have an extension oriented toward the longitudinal axis 420, said extension being configured to interact with the cam grooves 328 of claws 322 and 324. In this case, a camshaft is not necessary as in the previous two embodiments, and the driven member is formed by these extensions.

[0181] Instead of having a camshaft mounted on the plate and a cam groove drilled in the jaws, a cam groove on the plate and a camshaft on the jaws can be used.

[0182] The structure of the motion conversion mechanism may differ from that shown in the figure. For example, the motion conversion mechanism may extend only on one side of the longitudinal axis. In other words, there may be only one plate 262 or 264.

[0183] In the example described, the driven member formed by the camshaft 268 may take another form, such as a cylinder, pin, cam, or roller.

[0184] In an alternative embodiment, the claws may translate relative to each other instead of rotating.

[0185] The rotary encoder 210 can be optical, magnetic, or mechanical. Alternatively, the rotary encoder 210 can also be an absolute encoder, although it is relatively bulky.

[0186] Instead, a remote power supply 224 and a remote control unit 82 are used, all of which can be embedded in the rapier along with the control unit 207 and the servo motor 208, so that the rapier can be completely autonomous within the shed.

[0187] The sword shaft can contain embedded energy storage capacitors. Such capacitors can be applied during sword movement, at specific locations, or by converting kinetic energy, light, or temperature into electrical energy.

[0188] Instead of data communication via wires or buses, data communication can be conducted wirelessly.

[0189] According to an option not shown in the invention, the servo motor 208 can be electrically isolated from the sword body 204 in order to avoid static electricity problems.

[0190] Instead of a brushless DC servo motor, the electric motor 208 can be a traditional DC motor or an AC motor.

[0191] Different control options and control architectures can be implemented using this invention. For example, in an alternative, the ECU 207 can be located outside the rapier head, particularly at a relatively far location within the loom.

[0192] This invention is compatible with the use of two stacked active sword shafts.

[0193] This invention can also be used in a taker rapier that works with a giver rapier, and in a giver rapier that works with a taker rapier.

[0194] The claws, especially their edges 322a and 324a, may have their surfaces coated with rubber, aluminum, or steel. Alternatively or additionally, these edges may be arched or sloping.

[0195] The cam groove 328 can be located in front of the rotation axis of the cam, as in the example of the attached figure with respect to axes A320, A322 and A324, but the cam groove and the associated camshaft can also be located behind these axes.

[0196] The alternative geometry of the cam groove allows for changes in the stroke, dynamics, and intensity of the force applied to the weft by the clamp.

[0197] The present invention is also applicable to the rapier head with a magnetic guide device that cooperates with the reed 23 of the loom 2, as disclosed in EP-A-2 829 646.

[0198] Regardless of the embodiments and variations considered above, the present invention utilizes a servo-driven fixture 320 and provides at least the following benefits:

[0199] - It allows the clamp to reach any position at any speed and torque within the limits of the electric motor's output capacity.

[0200] - Different closing positions can be defined to capture different weft yarns.

[0201] - It allows access to any angular position for clamping the yarn.

[0202] - It allows for the use of weft materials and the fixing of the angular position for clamping between picks, as well as the adjustment of the clamping force of the claws.

[0203] It provides two parallel clamping edges to effectively capture the weft yarn.

[0204] - It allows the closing motion of the claws to be adjusted by adjusting the torque transmitted by the servo motor, while taking into account the friction of the weft yarn traveling in the shed.

[0205] - It allows adjustment of the closing motion and position of the claw based on the tension / braking conditions of the weft yarn in the weft selector or any feeding device.

[0206] - It allows checking for the presence of weft material at the pickup location by measuring the torque transmitted by the servo motor near the pickup location.

[0207] - It allows checking the weft yarn thickness / yarn count by detecting the angular position of the claw when it leaves the pick-up position.

[0208] - It allows, for example, checking that the yarn has not been lost between the pick-up and release positions by verifying that the torque applied in the verification phase Φ3 varies by no more than 20% between time t4 and t5.

[0209] - It allows for continuous opening / closing movements of the claw and checks whether the weft yarn has been correctly released at the release position P3 by checking whether the closed position corresponds to the zero value of angle θ.

[0210] It also allows determining whether the gripper is empty by implementing small movements of the claw along a set position based on a given signal for the weft yarn. If the gripper is not empty, the sensed position will remain within a given range around the set position.

[0211] It allows for the determination of the length of the unwound weft yarn. Once the clamp is empty, the control unit 207 can detect a successful release. Using information about the cutting time, pull-in time, and rapier speed, the controller correlates the available data to determine the length of the weft yarn that has been captured, pulled in, cut, and released into the shed.

[0212] - It allows for inspection of the weft yarn position in small, inaccessible sheds.

[0213] - It does not rely on springs to close the clamps. Its movement is precisely controlled.

[0214] The embodiments and alternative embodiments considered above can be combined to generate new embodiments of the invention within the scope of the appended claims.

Claims

1. A rapier (20) for pulling a weft yarn (34) from a pick-up position (P1) into the shed of a loom (2) along a pull-in path (Y20), the rapier comprising: - A sword head (206) is installed at one end of the sword shaft, the sword head extending along the main longitudinal axis (A20) of the sword shaft and driven by a drive member (203) along the pull-in path; - A clamp (320) for capturing the weft yarn, the clamp being mounted in the rapier head and operable between an open and closed configuration; - An actuator (208) mounted on the rapier shaft is used to actuate the clamp; as well as - Motion conversion mechanism (260 to 328), the motion conversion mechanism being used to convert the output motion of the actuator into the opening or closing motion of the clamp. The actuator is an electric motor (208), and the output motion of the electric motor is a rotation about a rotation axis (A208) that is parallel to the main longitudinal axis (A20) of the sword (20).

2. The sword shaft according to claim 1, wherein, The motion conversion mechanism (260 to 328) is configured to operate the clamp (320) from its closed configuration to its open configuration when the output shaft (208a) of the electric motor (208) rotates about the rotation axis (A208) in a first direction (R1), and to operate the clamp from its open configuration to its closed configuration when the output shaft (208a) of the electric motor rotates about the rotation axis in a second direction (R2) opposite to the first direction.

3. The sword shaft according to claim 2, wherein, The motion conversion mechanism (260 to 328) includes a slider (260) capable of translational movement between a first longitudinal position and a second longitudinal position along a direction parallel to the main longitudinal axis (A20). The slider is configured to operate the clamp (320) from its closed configuration to its open configuration when the slider moves from its first longitudinal position to its second longitudinal position, and to operate the clamp from its open configuration to its closed configuration when the slider moves from its second longitudinal position to its first longitudinal position.

4. The sword shaft according to claim 3, wherein, The slider comprises a group of two plates (262, 264) extending parallel to the main longitudinal axis (A20) on two lateral sides of the main longitudinal axis. Each plate comprises a first sliding surface and a second sliding surface (279, 281) that are separated from each other along the main longitudinal axis and configured to slide along a corresponding guide surface (S294) disposed on a frame (290) of the rapier head (206).

5. The sword shaft according to any one of claims 1 to 4, wherein, The clamp includes two claws (322, 324), wherein at least the first claw (322) is hinged about a pivot axis (A322; A320) perpendicular to the main longitudinal axis (A20) relative to the frame (290) of the rapier head (206), wherein the first claw extends along the longitudinal axis at least between the pivot axis and the claw tip (322a), the claw tip being configured to engage with the other claw (324) of the clamp to capture the weft yarn (34) to be pulled into the shed.

6. The sword shaft according to any one of claims 1 to 4, wherein, The clamp includes: a first pawl (322) hinged to a frame (290) of the sword head (206) about a first pivot axis (A322; A320) perpendicular to the main longitudinal axis (A20); and a second pawl (324) hinged to the frame of the sword head about a second pivot axis (A324; A320) perpendicular to the main longitudinal axis, wherein the first pivot axis and the second pivot axis (A322, A324; A320) are parallel and / or overlap.

7. The sword shaft according to claim 6, wherein, The first claw (322) and the second claw (324) extend symmetrically on both sides of the main longitudinal axis (A20), and the motion conversion mechanism (260 to 328) applies opposing forces to the first claw and the second claw to pivot the first claw and the second claw toward or away from each other relative to the main longitudinal axis (A20).

8. The sword shaft according to any one of claims 3 and 4, wherein, - The clamp includes two claws (322, 324), wherein at least the first claw (322) is hinged about a pivot axis (A322; A320) perpendicular to the main longitudinal axis (A20) relative to the frame (290) of the rapier head (206), wherein the first claw extends along the longitudinal axis at least between the pivot axis and the claw tip (322a), the claw tip (322a) being configured to engage with the other claw (324) of the clamp to capture the weft yarn (34) to be pulled into the shed. - The first claw (322) is provided with a groove (328) and the slider (260) is equipped with a driven member (278) engaging in the groove of the first claw, or the slider (260) is provided with a groove and the first claw is equipped with a driven member (278) engaging in the groove of the slider. as well as - The groove is configured to guide the driven member engaged in the groove and is configured to convert the translational motion of the slider (260) parallel to the main longitudinal axis (A20) into the pivoting motion of the first claw (322).

9. The sword shaft according to claim 8, wherein, - The groove (328) has a curved profile extending between a first end (328a) and a second end (328b); - When the driven member (278) is at the first end (328a), the clamp (320) is in its open configuration; - When the driven member is at the second end (328b), the clamp is in its closed configuration; as well as - The second end (328b) of the profile extends by a distance (d3) measured parallel to the main longitudinal axis (A20), which is less than 35% of the distance (L320) between the pivot axis (A322, A324) and the claw end (322a, 324a) measured along the main longitudinal axis.

10. The sword shaft according to any one of claims 3 and 4, wherein, - The slider (260) is equipped with a nut (266) integral with or rotatably fixed to the slider, and the electric motor (208) is equipped with a threaded rod (284) engaged in the nut; or - The electric motor (208) is equipped with a nut that is integral with or rotatably fixed to the electric motor, and the sliding member (260) is equipped with a threaded rod that engages in the nut. This converts the rotational motion of the output shaft (208a) of the electric motor into the translational motion of the slider.

11. The sword shaft according to any one of claims 1 to 4, wherein, The scissor includes: a position encoder (210) for measuring geometric parameters representing the opening of the clamp (320), and / or a torque controller (212) for measuring the torque transmitted by the electric motor (208).

12. The sword shaft according to claim 5, wherein, The claw tip is a clamping edge (322a) perpendicular to the main longitudinal axis.

13. The sword shaft according to claim 8, wherein, The claw tip is a clamping edge (322a) perpendicular to the main longitudinal axis.

14. The sword shaft according to claim 9, wherein, The second end (328b) of the profile extends by a distance (d3) measured parallel to the main longitudinal axis (A20), which is less than 25% of the distance (L320) between the pivot axis (A322, A324) and the claw end (322a, 324a) measured along the main longitudinal axis.

15. A method for drawing a weft yarn (34) into a shed (S) on a loom (2), the loom comprising: -Warp yarn transfer unit; -Heddle wire (17) used to move the warp yarns in order to form the shed; - shed forming mechanism (6), which causes the heddle wire to move; - Weft bobbin (26), which supplies weft yarn to the loom; and - Used to pull the weft yarn from the pick-up position (P1) into the rapier (20) in the shed along the pull-in path (Y20). The method includes at least the following steps: a) Capture (Φ3) the weft yarn (34) at the pick-up position (P1); b) Pull the weft yarn along the pull-in path (Y20) into the shed to the predetermined position (P3); c) Release the weft yarn (Φ4) at the predetermined position (P3); as well as d) Remove the rapier from the predetermined position (P3) of the shed; in, - The method is carried out using the rapier (20) according to any one of claims 1 to 14, and -Measure the geometric parameter (θ) representing the opening of the clamp and the parameter (T) representing the clamping force during at least one of steps a), b), or d). mot At least one of the parameters (θ, T) is used, and the value of the measured parameter (θ, T) is compared with the threshold (θ). T T T This can be compared, or two values ​​of a parameter measured during two different steps can be compared with each other.

16. The method according to claim 15, wherein, The geometric parameter (θ) representing the opening of the clamp (320) or the parameter (T) representing the clamping force. mot )respectively, -The angular position of the output shaft (208a) of the electric motor (208) about the axis of rotation (A208) is measured by the electric motor (208), or -Measured as the torque (T) applied to the clamp by the electric motor (208). mot The physical values ​​are proportional to each other.

17. The method according to claim 15, wherein, -At step c), the clamp (320) is placed in its open configuration; - During step d), a sub-step is performed, the sub-step comprising: -d1) Move the clamp from its open configuration (Φ5) to its closed configuration. -d2) Measure the geometric parameters (θ) representing the opening of the clamp in the closed configuration. And among them, -Measured in at least one of steps a), b), or d) and compared with the threshold (θ) T The geometric parameters being compared are the geometric parameters (θ) measured at sub-step d2), or - The two values ​​of the geometric parameter (θ) measured during the two different steps are included in the values ​​measured in sub-step d2).

18. The method according to claim 17, wherein, The value of the geometric parameter (θ) representing the opening of the fixture (320) measured during step b) is compared with the value of the same geometric parameter measured during sub-step d1).

19. The method according to claim 15, wherein, The rapier (20) is a rapier according to any one of claims 5 to 14, wherein the clamping force applied by the clamp (320) in its closed configuration or the angle (θ) between the two claws (322, 324) of the clamp at the pickup position can be adjusted between two consecutive pickups according to parameters depending on the weft yarn characteristics or according to external parameters, and wherein the clamping force or opening of the clamp is measured by the electric motor during step a).

20. A loom (2) for weaving a fabric using warp yarns (18) and interlaced weft yarns (34), the loom comprising: -Warp yarn transfer unit; -Heddle wire (17) used to move the warp yarns in order to form the shed; - A shed forming mechanism (6) that causes the heddle wire to move; - Weft bobbin (26), which supplies weft yarn to the loom; and - Used to pull the weft yarn from the pick-up position (P1) into the rapier (20) in the shed along the pull-in path (Y20). The rapier (20) is a rapier according to any one of claims 1 to 13, and includes an embedded control unit (207) communicating with the main control unit (82) of the loom (2), and the embedded control unit controls the electric motor (208) of the rapier based on data provided by the main control unit of the loom.

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