Patent ID: 12258690

DETAILED DESCRIPTION

Braiding is a process including intertwining at least three yarns in order to create a continuous structure that may be referred to as a braid. A twist may be created using only two yarns. The braid may be produced by moving around carriers on a bedplate. A bedplate may be flat, conical, frustoconical, or cylindrical. A bobbin of yarn is placed on top of each carrier. Paths of the carriers, which may be grooved into the bedplate, intersect each other so as to selectively cause the yarns to intertwine together, hence creating the braid. A pulling mechanism is placed on top of the bedplate in order to pull the yarns and the braided product away from the bedplate.

Referring toFIG.1, a braiding machine is shown at10. The braiding machine10includes a frame12for supporting a plurality of gears14that are rotatable about respective axes. In an embodiment, the gears14are horn gears. For simplicity, the expression horn gear14is used herein, although other types of gears may be used. An overhead structure16may be present to exert a pulling action on yarns provided by carriers20. The braiding machine10includes a plurality of the carriers20, i.e., two or more, that are movable one relative to the others thanks to the gears14. Each of the carriers20carries a one or more bobbin of yarns. The braiding machine10creates a braid by relatively moving the carriers20with the horn gears14thereby intertwining yarns carried by the carriers20.

The braiding machine10may be used to braid yarns of various types, which may include fibers, such as carbon or glass fibers, in a way to meet target geometrical and mechanical performance of a product. The braided fibers may then be impregnated with polymer materials to form a composite material. During braiding, the fibers or yarn are maintained under tension to obtain the target geometry. The carriers20disclosed herein may allow to control the tension on the yarn.

Carrier

Referring toFIGS.2-3, one of the carrier20is shown in greater detail. The carrier20includes a housing21that is engageable by the horn gears14of the braiding machine10. The carrier20includes a spool22that is rotatably supported by the housing21via two arms23. Particularly, each of the two arms23may be cantilevered relative to the housing21and supports axial ends of an axle24(FIG.4) that supports the spool22. An inverted U-shaped structure or a single arm23could be used as examples of alternatives to the two arms23. The carrier20includes a motor25(FIG.3) that is disposed concentrically within the spool22. Therefore, a shaft of the motor25may be secured to the two arms23and powering of the motor25results in a casing of the motor25rotating about a rotation axis R with the spool22, as one possible arrangement. The rotation axis R may be generally horizontal, with a view of having a yarn pulled upwardly, i.e., generally transversely to the rotation axis R. The orientations are relative to one another, and may be changed depending on the orientation of the machine10.

A control system30is located within the housing21and will be described herein below with reference toFIG.4, the control system30being for example a PCB, a small processor, etc. The control system30is operatively connected to the motor25and operatively connected to an encoder26that is secured to the spool22. The encoder26is operable to supply data about a position and movement of the spool22relative to the arms23to the control system30. The control system30is operable to control a tension in the yarn that is wrapped around the spool22.

The carrier20may include a yarn level measuring system27that is operatively connected to the control system30operable for providing data to the control system30about a length of fiber remaining in the spool22. More particularly, as the yarn is wrapped around the spool22, the yarn increases an effective diameter of the spool22. As the yarn gets consumed, this effective diameter decreases until no more yarn is wrapped around the spool22and in which the effective diameter of the spool22becomes the nominal diameter of the spool22, that is, the diameter of the spool22when it is free of yarn. This change in diameter may affect how a torque generated by motor25varies the tension in the yarn. Particularly, for a same torque generated by the motor25, the tension in the yarn will be greater if the effective diameter is smaller.

In the embodiment shown, the yarn level measuring system27includes an arm27apivotably engaged to the housing21via a mount27b, which is secured to the housing21. Idler wheels27care rotatably supported at a distal end of the arm27aand used to rollingly engage the yarn. The idler wheels27cmaintain a slight pressure against the yarn thanks to a biasing member27d, such as a spring, engaged to the arm27aand to the mount27b. A sensor, herein a potentiometer27e, may be located within the mount27band may be operatively connected to the arm27a. The potentiometer27eis operatively connected to the control system30to supply data to the control system30about a level or condition of yarn in the spool22. For instance, a magnitude of a current going through the potentiometer27eis altered in function of a position of the arm27a.

It will be appreciated that any other suitable sensor operable to indicate a level of yarn into the spool22is contemplated. For instance, an optical sensor or an ultrasonic distance sensor may be used.

Referring more particularly toFIG.3, the housing21includes a top portion21aand a bottom portion21bsecurable to the top portion21a. The housing21defines an internal chamber21cthat is sized to house the control system30and a battery28that is operatively connected to the control system30and to the motor25. The battery28is centered within the housing21since it is the component that determines the size of the housing21. The housing21may be airtight to limit dust from entering the internal chamber21cof the housing21. A seal may be used to seal gaps between the top and bottom portions21a,21bof the housing21. The battery28is one possible way to power the control system30, with brush type arrangements being another embodiment.

Referring more particularly toFIG.4, the control system30is illustrated in greater detail. The carrier20has a charge connector29operatively connected to the battery28for charging the battery28. In the embodiment shown, the battery is a lithium-polymer four-cells battery of 14.8 Volts and having a capacity of 5000 mAh, as an example. This battery28may provide the carrier20with an 8-hour autonomy. The battery28is operatively connected to a battery management system28aused for balancing the different cells of the battery28and to protect the battery28if it becomes depleted. The charge connector29is operatively connected to the battery28via the battery management system28a.

The control system30includes a controller31having a processor31aand a computer-readable medium31boperatively connected to the processor31a, the readable medium31bbeing for example a non-transitory computer-readable memory communicatively coupled to the processor31aand comprising computer-readable program instructions executable by the processor31a. The controller31is operatively connected to the encoder26, to the motor25, and to a transmission module32that is used to supply data to the carrier20and retrieve data20from the carrier20. The transmission module32is herein a wireless module. In the embodiment shown, the transmission module32is a Raspberry Pi™ zero wireless. All of the controller31, the transmission module32, the battery management system28a, the battery28, the transmission module32are contained within the housing21. The controller31may have a voltage regulator31cthat is operatively connected to the encoder26and to the motor25. The voltage regulator31cis operable to control a power supplied to the motor25to control the tension in the yarn. The controller31is further operatively connected to the potentiometer27eto receive data about a level of yarn remaining in the spool22.

The motor25may be a BR2212 BLDC motor. The encoder26may be a AMT102-V encoder. The controller31may be a BDDrive V1 with an on-board voltage regulator XL6009. Any other suitable components may be used without departing from the scope of the present disclosure. In the depicted embodiment, the housing21has a diameter of about 11 cm. The carrier20has a height of about 26.5 cm. The controller31may be an ODrive Robotics™ circuit.

Referring now toFIGS.5-6, another embodiment of a carrier is shown at120. This carrier120may be used in a process called “pultrusion”. Pultrusion is a continuous process in which yarns are unidirectional, woven or braided and impregnated with resin and pulled through a heated stationary die where the resin undergoes polymerization. The impregnation may be done by pulling the yarns through a bath of resin or by injecting the resin into an injection chamber.

In the pultrusion process, the yarns are pulled and the carriers120are used to control a rate at which the yarns get unwound from the spool to control the tension in the yarns. The carriers120do not need to move one relative to the other as may be the case for the braiding machine10ofFIG.1.

The carrier120has a housing121and a spool122rotatably supported by the housing121. The spool122is a rotary axle sized to engage bobbins and a tightening mechanism123is used to tighten the bobbins on the spool122so that the bobbins and the spool122rotate concurrently. In the embodiment shown, the tightening mechanism123includes a sprocket wheel123ahaving a member secured thereto threadingly engaged to the spool122. The spool122defines a plurality of sections123b, which are cantilevered. The sections123bare radially deformable relative to a rotation axis A of the spool122. Fastening the sprocket wheel123aand its member secured thereto into the spool122deforms the sections123bradially outwardly away from the rotation axis A until the sections123bare abutted against and frictionally engaged to the bobbin. The housing121is sized to receive the motor125, the encoder26, and a control system130. A connector129is secured to the housing21and is operatively connected to the control system130for powering the carrier120. The encoder26is secured above the motor125to obtain the position of the motor125. The motor125may be a MC5206 BLDC motor. The connector129may receive an input voltage from 12 to 24 Volts.

Referring toFIGS.7-8, the motor125is in driving engagement with the spool122via a transmission140including a first pulley141drivingly engaged to the motor125, a second pulley142drivingly engaged to the spool122, and a strap143wrapped around the first pulley141and the second pulley142for transmitting a rotation of the first pulley141to the second pulley142. Idler pulleys144, two in the present embodiment, are engaged by the strap143and are used to maintain appropriate tension in the strap143. The idler pulleys144may be slidingly engaged within grooves defined through a wall of the housing121to increase or decrease the tension in the strap143. The pulleys141,142may be sprockets, and a chain may be used. It will be appreciated that the transmission may be any suitable means able to transmit a rotational input from the motor125to the spool122without departing from the scope of the present disclosure. For instance, a gearbox may be used.

The housing121defines inner walls121dand guides121e. The guides121eare sized for receiving the alimentation cables therebetween. The inner walls121dmay extend along an entire height of the housing121, from a top wall to a bottom wall thereof, and may substantially define a first chamber121f(FIG.8) enclosing the motor125and the transmission140, and a second chamber121g(FIG.8) separate from the first chamber121f. The second chamber121gmay house the control system130. Therefore, in the embodiment shown, the electrical components (e.g., controller31) are substantially isolated from the spool and transmission140.

As illustrated inFIG.7, ventilators150, two in the embodiment shown, are secured to the housing121and are operable to create an airflow between the second chamber121gof the housing121and an environment outside the housing121. This airflow may cool the different components of the control system130that are located inside the housing121. These ventilators may have a diameter of about 40 mm. The ventilators150are used to increase a pressure inside the housing121beyond that of the environment outside the housing121to limit dust from penetrating the housing121.

Referring toFIGS.6-7, the spool122is rollingly engaged to the housing121. Particularly, the spool122is secured to the second pulley142for concurrent rotation therewith. The spool defines a groove122athat is rollingly engaged by idler wheels122b, five idler wheels122bbeing present in this embodiment. The idler wheels122bare rotatably supported by two arcuate members122cthat extend around a circumference of the spool122. The two arcuate members122care secured to the housing121. The idler wheels122bare in engagement with the groove122afor guiding a rotation of the spool122. The idler wheels122bmay be V-wheels. Nuts122dare engaged to the housing121and to one of the two arcuate members122c. The nuts122dmay be removed to remove the one of the two arcuate members122cthereby allowing the spool122to be separated from the housing121and replaced if need be. The nuts122dare used to maintain a relative position between the two arcuate members122cto maintain the idler wheels122bin rolling contact with the spool122.

Referring now toFIG.9, the control system130of the carrier120is shown in greater detail. The control system130includes the controller31having a processor31aand a computer-readable medium31boperatively connected to the processor31a, the readable medium31bbeing for example a non-transitory computer-readable memory communicatively coupled to the processor31aand comprising computer-readable program instructions executable by the processor31a. The controller31is operatively connected to the encoder26, to the motor125, and to the transmission module32that is used to supply data to the carrier20and retrieve data20from the carrier120. The transmission module32is herein a wireless module. In the embodiment shown, the transmission module32is a Raspberry Pi™ zero wireless. All of the controller31, the transmission module32, the battery management system28a, the transmission module32are contained within the housing121. The controller31has a voltage regulator31cthat is operatively connected to the encoder26and to the motor125. The voltage regulator31cis operable to control a power supplied to the motor125to control the tension in the yarn.

The control system130is similar to the control system30described above with reference toFIG.4, but lacks the battery and the battery management system. That is, the carrier120may be powered via cables connected to the power connector129. In the pultrusion process, the carriers120may not need to move one relative to the other and, consequently, may not need a battery and may be directly connected to a power grid. Although not illustrated inFIGS.6-7, the carrier120also includes the yarn level measuring system27described above with reference toFIGS.2-3. The controller31is further operatively connected to the yarn level measuring system27as explained herein above. That is, the controller31is further operatively connected to the potentiometer27eto receive data about a level of yarn remaining in the spool22.

Referring toFIG.10, the controller31may comprise any suitable devices configured to implement a method200such that instructions, when executed by the controller31or other programmable apparatus, may cause the functions/acts/steps performed as part of the method200as described inFIG.10to be executed. The processing unit31amay comprise, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, a central processing unit (CPU), an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuits, or any combination thereof.

The computer-readable medium31bmay comprise any suitable known or other machine-readable storage medium. The computer-readable medium31bmay comprise non-transitory computer readable storage medium, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The computer-readable medium31bmay include a suitable combination of any type of computer memory that is located either internally or externally to device, for example random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically-erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like. Computer-readable medium31bmay comprise any storage means (e.g., devices) suitable for retrievably storing machine-readable instructions executable by processing unit31a.

The method200for operating the carrier20and/or the carrier120described herein may be implemented in a high level procedural or object oriented programming or scripting language, or a combination thereof, to communicate with or assist in the operation of a computer system, for example the controller31. Alternatively, the method200may be implemented in assembly or machine language. The language may be a compiled or interpreted language. Program code for implementing the method200may be stored on a storage media or a device, for example a ROM, a magnetic disk, an optical disc, a flash drive, or any other suitable storage media or device. The program code may be readable by a general or special-purpose programmable computer for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein. Embodiments of the method200may also be considered to be implemented by way of a non-transitory computer-readable storage medium having a computer program stored thereon. The computer program may comprise computer-readable instructions which cause a computer, or more specifically the processing unit31a, to operate in a specific and predefined manner to perform the functions described herein, for example those described in the method200.

Computer-executable instructions may be in many forms, including program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.

The method200comprises the steps of receiving data about a desired tension in the yarn202; determining operation parameters of the motor25,125based on the received data204; and operating the motor25,125per the determined operation parameters to create the desired tension in the yarn206.

In the embodiment shown, the receiving of the data includes receiving data about a quantity of yarn remaining around the spool22,122. The receiving of the data about the quantity of the yarn may include receiving a signal from a sensor such as the potentiometer27eindicative of the quantity of the yarn remaining. Determining of the operation parameters includes determining a torque generated by the motor25,125. The determining of the torque includes determining a current and/or tension to be supplied to the motor25,125to achieve the determined torque. The receiving of the data includes receiving data about an angular position of the motor. The angular position may be supplied by the encoder26.

The control system30,130is configured to control an input current supplied to the motor25,125to control the torque generated by the motor25,125. Based on the quantity of yarn remaining on the spool22,122, which is provided by the yarn level measuring system27, the controller31is able to calculate the tension exerted on the yarn.

The controller31may be able to store a database to operate the carrier20,120. The controller31may be able to supply data that is visualized by a user in real time. This data may include, for instance, current to the motor, tension of the power supplied to the motor, the amount of yarn remaining in the spool22,122, tension in the yarns, and so on. Each of the communication module32of each of the carriers20,120of the braiding machine10or pultrusion machine may communicate with a central controller operable by a user, who can visualize the data and control operation of the processes. That is, a user may wirelessly send control commands to the carriers20,120in real time. The user may control the tension wirelessly in real time via the communication module32.

In a particular embodiment, the carriers20,120allow the programming on-demand of each of the carriers of the braiding machine10individually (FIG.1). The tension in the yarns may be modified without any modification to the carriers. The tension may be adjusted in real time during the braiding process. This may allow the creation of a braid of complex and variable geometry. Moreover, the carriers20,120may rewind the yarn on the spool22when the yarn is not under sufficient tension. This may allow braiding in three dimensional geometries. The disclosed carriers20,120may allow real-time data to be obtained thanks to the bi-directional communication between a control center and each of the carriers. This may allow the building of a database from the plurality of carriers20,120. This database may be loaded on the braiding machine10for braiding composite yarns. The database may allow a control of each manufacturing step of the composite yarn. Any abnormality may be detect as soon as it appears. This may allow a reduction of operation costs. The carriers20,120may rewind some of the yarns of a braid to change its structure and its geometry during the braiding process. The braiding machine10may be used, for instance, to manufacture composite yarns that may go into fabricating aircraft fuselage, pressurized reservoir, variable geometry beams, sticks, turbine blades, landing gears, and so on.

Braiding Machine

Referring toFIG.11, a braiding machine in accordance with one embodiment is shown at300. The braiding machine300includes a bedplate302, i.e., a table or like supporting structure, supporting a plurality of horn gears304. A plurality of carriers220are engaged by the gears304, such as horn gears, to move the carriers220along a predefined path defined by a track320a(FIG.12) of the bed plate302. The carriers220include spools222and tensioner224for creating a tension in the yarns wrapped around the spools222while it is being pulled by a pulling mechanism306of the braiding machine300. The carriers220may be for example the carriers20described herein.

Referring more particularly toFIG.12, the horn gears304are discs with a number of evenly spaced notches304aaround their circumferences. These notches304acontain the carriers220during their movement. That is, each of the carriers220has a shaft engageable within the notches304aof the horn gears304. The horn gears304are placed on the bedplate302according to a grooved path. Each horn gear304rotates in the opposite side of its neighbours. When two notches304aof two adjacent horn gears304are in register with one another, the carrier220is transferred from one horn gear304to a neighbouring horn gear304. The carriers220therefore follow the track302aby being passed from one horn gear304to the next.

The braiding architecture in a textile fabric has a great impact on its mechanical properties. The position of each intertwined yarn, dictated by the speed and trajectory of the carriers, defines the braid geometry. With the horn gear system depicted inFIG.12, the path followed by the carrier is fixed and cannot be altered. This fix trajectory limits the braid to a fixed shape with a constant braiding pattern. In order to create a complex preform with a continuous variable shape, carriers' trajectory needs to be modifiable. In this case, greater mechanical properties could be reached and the position of each intertwined yarn could be controlled at any time during the braiding process.

Referring now toFIG.13, a braiding machine has a matrix400of gears402, with adjacent pairs of the gears402being evenly spaced apart from one another, the gears402being rotatable about their respective rotation axes, but in either direction, i.e., clockwise and counter clockwise. The matrix of gears may be flat, conical, cylindrical. All of the gears402are secured to a support structure401and are substantially coplanar. The rotation axes of the gears402are normal to a plane defined by the support structure401. Each of the gears402may be engaged by a respective bi-directional motor403to be individually rotated in a clockwise direction or a counter clockwise direction. The motors403may be servo actuator such as Dynamixel™, AX-12aactuators. Such an actuator may provide a high torque while having a compact frame. This actuator has an internal closed loop control system that may allow a higher accuracy for speed, position, and torque commands. All of the motors403are operatively connected to a controller, which may be a ArbotiX-M Robocontroller™ board.

Referring toFIGS.13-14, a chain410(a.k.a., a link, a chain link) is engageable by the gears402and movable by the gears402along a path. The path may be selected by controlling the direction of rotation of the different gears402and is nota fixed path contrary to the horn gear configuration described above with reference toFIG.12.

The chain410includes three or more rollers411, also referred to as cylindrical shafts, disposed longitudinally about a longitudinal axis L of the chain410. The rollers411are connected to one another via arms or links412. In the embodiment shown, the chain410of three rollers411defines a pivot axis P allowing the chain410to change shape. That is, the chain410has two or more sections413connected to one another at a pivot point414and pivotable one relative to the other about the pivot axis P defined by the pivot point414. The pivot axis P is normal to the plane of the support structure401. It will be appreciated that the chain may include more than three rollers and define more than two sections. For a chain of “n” rollers, the chain has “n−1” sections and “n−2” pivot points. For instance, a 4-roller chain has three sections connected to one another via two pivot points. The rollers411have a cylindrical shape in order to fit in notches402aof the gears402. The rollers411may be rotatable about respective roller central axes.

Opposed ends of the chain410define flanges415that protrude away from the longitudinal axis L. These flanges415may provide stability to the carriers20,120,220when the carriers20,120,220are moving, or ensure that the chains410are constrained to a planar movement in a plane of the support structure401. In the embodiment shown, some of the flanges415are defined by the links412. Some other of the flanges415are defined by separate parts secured to the chain410.FIG.15illustrates a plate416that may be used as an interface to connect the carriers20,120,220to the chain410. As illustrated, a footprint of the bottom plate220ais greater than that of the chain410. Moreover, a center of the carriers220may be in register with the pivot point P of the chain410.

It will be appreciated that a braiding machine may include any of the carriers20,120described herein above with reference toFIGS.2and5with the matrix400and chain410system described herein.

Referring toFIGS.16-18, another embodiment of a gear is shown at502. The gear502includes nine equidistantly spaced notches502a. The gear502has a radius R and the notches502aare spaced apart from one another by a distance b. In the embodiment shown, free ends of teeth502bare contained within a circle having the radius R. The distance b between two adjacent notches is a straight line between centers of the two notches502a. The distance b also corresponds to the distance between centers of two adjacent rollers411. The notches502ahave a diameter D that is herein generally equal to or slightly larger than a diameter of the rollers411shown schematically inFIG.18. A center of the diameter D of the notches502ais at a point of a tangent to a circumference of the gear502as shown with dashed lines inFIG.16. As illustrated inFIG.18, a length of the link412substantially corresponds to the spacing b between two adjacent notches502a. As shown inFIG.16, a depth d of the notches502agenerally corresponds to or is slightly large than a radius of the rollers411, which is half the diameter D.

Referring toFIG.17, an hexagonal compact arrangement of three gears502is shown. The gears502are in close contact. The dimension x is the free length between the circumference of the gear502and a contact point between two adjacent gears502. A diameter of the rollers411is selected to limit mechanical blockage. In some embodiments, D is close to b while letting the teeth502bof the gears502to extend to the circumference of the gears502.

The dimension x may be calculated as follows:
x=(√{square root over (3)}−1)R

Whereas the dimension b is calculated as follows:

b=2⁢R⁢sin⁡(πN)

Where N is the number of notches502aof the gear502.

The number of notches is selected as to prevent the chain410from buckling. This may imply that b is less than x. If b is greater than x, the chain410might cause a mechanical blockage when transitioning from a gear502to the adjacent gears502. Moreover, to facilitate the engagement of the chain410in the adjacent gears502, which is responsible for steering, b is close to x.

To determine the number of notches N, the following equations are resolved:

b<x2⁢R⁢sin⁡(πN)<12-22⁢R
This Yields:

N>πsin-1(3-12)

This means that N is greater than 8.3835. This design equation fixes the number of notches for the hexagonal compact arrangement of gears to 9. In the embodiment shown, the gears have a gear radius R of 33.25 mm. The dimension x is 24.3 mm. Each notch502aand chain rollers411, have a diameter of D of 21.92 mm.

Referring now toFIGS.19ato19f, a movement of a chain410relative to a portion of the matrix400ofFIG.13is illustrated. Only a portion of the matrix400is illustrated. Each of the gears402has nine notches402aas established per the calculations above.

In order to move the chain410around the support structure401, the gears402cooperate to orient the chain410. As shown inFIG.19b, a bottom one of the gears402rotates clockwise and orient the chain410toward the right. The upper and left gears402rotate respectively in counter clockwise and clockwise direction to push the chain410along the direction imparted by the bottom gear402as shown inFIG.19c. Further rotation as illustrated inFIG.19dresults in a leading roller of the chain410to be received in a notch402aof the right gear402as shown inFIG.19e. At that point, the chain410can go left and downwards by rotating the left gear in a clockwise direction and by soliciting the cooperation of the other gears402.

As shown inFIG.19a, the chain410is located between the top and left gears and reaches an intersection between two possible paths P1, P2. Each of the paths is defined by two adjacent gears. A shown inFIG.19b, the bottom gear410is powered in a clockwise direction to orient the chain410toward the second path P2. The bottom gear therefore acts as a steering gear. As shown inFIGS.19cto19e, the top, bottom, and left gears410are powered to move the chain410in the second path P2. As shown inFIG.19f, the chain410reaches another intersection between two paths P3and P4. The right gear now becomes the steering gear and may rotate in a clockwise direction to orient the chain in the path P3or in the counter clockwise direction to orient the chain toward the path P4. The left, top, and bottom gears are then powered to move the chain in either one of the two paths P3, P4.

In the depicted embodiment, at least some of the gears of the matrix arranged to form a path between a pair of adjacent ones of the gears to lead to two distinct paths P1, P2with other adjacent ones of the gears, each of the two distinct paths defined by two of the gears, the two of the gears including one of the pair of the adjacent ones of the gears and another gear.

In the embodiment shown, the cycle of displacement can be divided into two sequential steps: a 10-degree rotation of the gear responsible to steer the chain410in a particular direction; and a 60-degree rotation of the three adjacent gears402allowing to move the402in the direction selected by the steering gear402. Therefore, the gears402perform two roles: moving the chain410; and steering the chain410. This dual role of the gears402is such that no other mechanism, such as a switch, a guiding foot, or a transfer mechanical system, is required to steer and move the chain410, and the carrier20,120,220secured thereto on the support structure401. The gears402are rotated in accordance with a determined sequence. In the embodiment shown, a gear402can only house one roller411at a time. This may allow a completely independent carrier movement and the carrier may move around the support structure401by successively operating sets of three gears402.

Referring toFIGS.20ato20l, different steps to create a standard flat braid are illustrated. Three chains410and three carriers220secured thereto are used to create this braid. For simplicity, the gears402are depicted as hexagons in those figures, though the gears40may be horn gears as those described above. InFIGS.20ato20k, the movements of each of the three chains410are depicted with arrows to show the steps required to create the braid.

InFIG.20a, a first chain410is moved south-east. InFIG.20b, a second chain410is moved north. InFIG.20c, a third chain410is moved south west. InFIG.20d, the first chain410is moved north. InFIG.20e, the second chain410is moved south east. InFIG.20f, the third chain410is moved north. InFIG.20g, the first chain410is moved south west. InFIG.20h, the second chain410is moved north. InFIG.20i, the third chain is moved south east. InFIG.20j, the first chain410is moved north. InFIG.20k, the second chain410is moved south west. InFIG.20l, the third chain is moved north. This process is repeated until the braid has the desired length.

Using the disclosed gears402and chains410, a cross-section of the braid may be varied along its length. This may be done by having one of the chains410, and carrier220secured thereto, set aside thereby winding only two yarns of the remaining carriers220. The chain410that was set aside can, after the two yarns have been wound around one another, rejoin them to continue the normal braiding process. With reference toFIG.20, to do the winding of the two yarns, two of the chains410and carriers220have to move simultaneously about a circular path while the third chain410is set aside on the side of the support structure401and remains immobile.

Consequently, by individually controlling any number of chains410by individual control of the motors moving the gears402, complex geometries of structure may be created. This is enabled by allowing a plurality of possible paths for each of the chains410. Each of the chains410and carriers20,120,220supported thereto is movable independently from the others. One or more of the chains/carriers may be parked on the side to punctually change the geometry of the braided structure and may re-integrate at any moment to resume the nominal geometry of the braided structure.

The disclosed system may allow to create braid with many thicknesses all connected to one another, within a single fabrication cycle. This is not possible using the horn gear system ofFIG.12. The disclosed system may allow braiding many different structures such has layers interconnected or non-interconnected, yarn winding, braid, unidirectional yarn, within a same braid. Moreover, the disclosed system may allow controlling the position of each yarn crossing. Mechanical properties of the braid may therefore be optimized. It may be possible to produce a braid by decreasing the amount of yarn required while still meeting the desired mechanical properties.

Referring toFIG.21, a matrix of gears402in accordance with another embodiment is shown. The gears402are disposed in an hexagonal arrangement. As shown, the gears402, in this arrangement, are equidistantly spaced apart from one another. In this embodiment, the chain moved by a pair of gears402may be directed in two different directions. In this arrangement, a gear402may have six neighbours. In this embodiment, the chain may be directed in six different directions. The matrix of gears402ofFIG.21may be viewed as a sample of a matrix of many other gears.

Referring toFIG.22, a matrix of gears402in accordance with yet another embodiment is shown. The gars402are disposed in a row-and-column arrangement. The distance between two gears402that are above one another is different than the distance between two gears402located on a diagonal. In this embodiment, the chain moved by a pair of gears402may be directed in three different directions. A gear402, in this matrix, may have up to eight neighbours. Again, the matrix of gears402ofFIG.22may be viewed as a sample of a matrix of many other gears.

In this matrix of gears, the chain410may be directed toward one of three different paths P5, P6, P7. In this embodiment, once the chain410reaches a crossroads of the three paths P5, P6, P7, two gears are powered in opposite direction to direct the chain in either one of those paths. For instance, to direct the chain in the vertically upward path P5, the two gears between which the vertically upward path P5is defined may be powered to move the chain in said path. Similarly, to direct the chain in the horizontal path P6, the two gears between which said path is defined are powered, and so on for the vertically downward path P7. Once the chain is engaged in one of these three paths P5, P6, P7, a third gear may be powered to move the chain. For instance, when the chain engages any of these three paths P5, P6, P7, the two gears that define the original path P0containing the chain as it reaches the crossroads of the three paths P5, P6, P7may be powered to move the chain.

In the embodiment shown, at least some of the gears of the matrix are arranged to form a path between a pair of adjacent ones of the gears to lead to three distinct paths P5, P6, P7with other adjacent ones of the gears, one of the three distinct paths defined by two of the gears, the two of the gears including, for the path P5or P7, one of the pair of the adjacent ones of the gears and another gear, or, for the path P6, two other gears, each of the two other gears adjacent a respective one of the gears of the pair of adjacent ones of the gears. The pair of adjacent ones of the gears defining the original path P0.

Referring toFIG.23, a matrix of gears602disposed in a row-and-column fashion is shown. The gears602have five notches each. Each of the gears602is individually motorized to displace the chain410on the support structure. The sequence of movements described above with reference toFIG.22may apply to this particular matrix of gears602.

Referring toFIG.24, a matrix of gears702disposed in a row-and-column fashion is shown. The gears702have six notches each. Each of the gears702is individually motorized to displace the chain410on the support structure. The sequence of movements described above with reference toFIG.22may apply to this particular matrix of gears702.

Referring now toFIG.25, a braiding machine is shown at700and includes the carriers220, three in the embodiment shown, having a tensioner224and a spool222. Each of the carriers220is secured to a respective chain410. A support structure401supports a plurality of the gears402described above with reference toFIG.13. The gears402are disposed in a hexagonal manner as illustrated inFIGS.13and21.

Referring toFIG.26, a controller for the braiding machine700is shown at800. The controller800includes a processing unit802and a computer-readable medium804operatively connected to the processing unit802. The controller800is operatively connected to the motors403of the gears402for controlling rotation of the gears402following instructions. Individually controlling of the gears may include powering a first one of the gears to orient the carrier toward one of the at least two distinct paths and powering at least a second one of the gears distinct than the first one of the gears for moving the carrier in the one of the at least two distinct paths.

That is, the computer-readable medium804may have stored thereon instructions characteristics of a given braid geometry to be created. These instructions may include a sequence of movements to be carried by each of the carriers220to achieve the braid geometry. The controller800therefore execute the instructions and control rotation of the gears402with their respective motors403to move the different carriers220with respect to the sequence of movements.

The controller800is configured for rotating the gears by powering the motors403for moving the chains410on the support structure401to braid the yarns. The controller800may be configured to obtaining data about a desired braid geometry. The data about the desired braid geometry may include obtaining data about a sequence of movements of the gears to move the chains on the support structure to obtain the desired braid geometry. The controller800may be able to create the sequence of movements in function of a desired braid geometry.

In a particular embodiment, the controller800of the gears403is operatively connected to the controllers31of each of the carriers20to allow a control of the tension the yarn in function of the position of the carriers20on the support structure, a speed of the carriers20, and any other suitable properties.

Referring now toFIGS.27to29, another embodiment of a link is shown at600. The link600includes a top plate601and a bottom plate602. Top and bottom do not necessarily entail a given orientation of the link600. Rollers603, three in the embodiment shown, are disposed between the top plate601and the bottom plate602. The rollers603includes a central roller and two lateral rollers. Each of the two lateral rollers603includes a central section603A, a top shank603B and a bottom shank603C. The top and bottom shanks603B,603C extend away from one another and protrude from the central section603A. Portions of the rollers603located between the two plates are sized to be engaged by teeth of gears as will be discussed below.

A central one of the rollers603remains substantially immobile relative to the top and bottom plates601,602. The lateral ones of the rollers603are able to move along direction depicted by arrow A1in relationship to the top and bottom plates601,602. In this regard, each of the top and bottom shanks603B,603C of the lateral rollers603rides within slots601A,602A defined by the top and bottom plates601,602. These slots601A,602A extend generally transversally to a longitudinal axis L along which the rollers603are distributed. The slots may be curvilinear, but any suitable shape is contemplated.

In the embodiment shown, biasing members604are used to bias the lateral rollers603toward a central position, a.k.a., neutral position, in which they are substantially centered within their respective slots601A,602A and aligned with the longitudinal axis L. The biasing members604includes herein biasing rods605that are fixedly secured at their center to one or both of the top and bottom plates601,602. Each of the two biasing rods605therefore defines two cantilevered rod portions605A,605B. The cantilevered rod portions605A,605B are able to exert a force on the top shanks603B of the lateral rollers603. The biasing rods605are able to ride within a recess601B, which may be shaped like a bowtie, and defined by the top plate601. In some embodiments, two additional rods may be mounted within a similar recess defined by the bottom plate602. As an alternative, leaf springs may be used as well.

The link600includes a guiding foot606, or guide606, that protrudes from the bottom plate602. The guiding foot606includes a front wedge606A and a rear wedge606B that may assist in guiding the link600within a correspondingly sized track as will be discussed below. The guiding foot606may be connected to the bottom plate602via fillets. Any suitable shape of the guiding foot606is contemplated.

It will be appreciated that a link may include more than three rollers. For instance, a link with five rollers, hence with five axes, may be used without departing from the scope of the present disclosure. More or less rollers may be used.

Referring now toFIGS.30-31, a matrix of gears is shown at900. The matrix900includes a plate901and a plurality of gears902rollingly engaged to the plate901for rotation about respective rotation axes. In the present embodiment, the gears902include each twelve teeth, but more or less teeth are contemplated. Each of the gears902may be individually controlled for moving the link600along a desired path. The gears902are herein disposed in a plurality of rows with the gears of two adjacent rows being staggered.

As shown inFIG.31, the plate901defines a plurality of tracks901A. Each of the tracks901A is sized to accept the guiding foot606of the link600. The tracks901A have a convergent section901B, a straight section901C, and a divergent sections901D. The straight section901C is located between the convergent and divergent sections901B,901D such that the convergent section901B converges toward the straight section901C, which then opens to the divergent section901D. A width of the straight section901C is sized to accommodate the guiding foot600. It will be appreciated that shapes of the different sections of the tracks901may be adjusted if need be.

In use, the guiding foot606enters the convergent section901B and is guided toward the straight section901C, which registers with a location where two adjacent gears are the closest to one another. When it exits the straight section901C, the divergent section901D allows the link to move along either one of the two possible directions depending of the rotation of the gears902. When such engagement is achieved, the link600is constrained to movement in a single translational degree of freedom.

The track901A may help in guiding the links600namely during their transition between the different gears902. This may prevent the links600from getting stuck between the gears902. Therefore, when the guiding foot600is located within the straight section901C of the track901A, it becomes constrained to a single degree of freedom, thereby reducing the risk of the link600getting blocked.

Because of the track901A in the plate901, it may be possible to increase a number of the teeth of the gears902, and, consequently, to increase a number of the notches defined between the teeth of the gears902. Herein, the gears902have 12 notches, but they may have more or less notches. In some embodiments, gears with twenty four notches may be used. These twenty four notch gears may be used with links having 5 rollers. In some embodiments, the notches of the gears may be deeper or shallower than illustrated inFIG.30and they may have a different shape than circular. This may improve the overall operation of the braiding machine. Roundover, chamfers, geometrical modifications of the notch may be used to smooth operation of the braiding machine as along as the rollers are able to easily enter the notches of the gears.

To control the gears902, a controller, such as the controller800described above with reference toFIG.26, is able to receive a geometric representation of a structure to be braided; to extract trajectories of the different yarns to obtain the braided structure; to convert these extracted trajectories into link trajectories of the links600, and of the carriers20,120,220mounted to these links600; and to control rotation of the different gears902to move the links600per the link trajectories. The algorithm may ensure that the different links600do not bump into one another, are not simultaneously on the same notch of the same gear902.

As can be seen therefore, the examples described above and illustrated are intended to be exemplary only. The scope is indicated by the appended claims.