Patent Description:
Fiber-reinforced plastics (FRP), also called fiber-reinforced polymers, for example carbon fiber-reinforced plastics (CFRP) are widely used materials for lightweight structures, ranging from sports equipment, to automotive components, to aircraft structures. A method for manufacturing of FRP's comprises depositing fiber tows, for example preimpregnated tows, for example tapes, onto a substrate. The depositing is, for example, done by a robot, for example a manipulator comprising a tape dispensing end effector for additive manufacturing. Depositing tapes imposes constraints on one or more of: the speed at which the tape is deposited, the trajectories described by the depositing end effector, the radius of curvature of the trajectories, the amount of adhesive polymer used, the amount of air trapped in the FRP, the fiber volume fraction inside the FRP, the deposition process temperature, the polymer's viscosity, the deposited layer's geometry, for example defined by its dimensions (for example defined by one or more of its length, width, and height), and the interleaving, juxtaposition, and superposition patterns of tapes, for example tape layers. <CIT> discloses a pressure foot device for applying an elongate fiber tow onto an object surface, the device comprising a foot surface for pressing the fiber tow onto the object surface, the foot surface comprising a straight foot segment for pressing the fiber tow onto the object surface. There is a need for systems and methods to deliver and apply fiber tows onto a surface to form an object. There is also a need to lay fiber tows over trajectories that comprise curves with small radii of curvature, and with improved and diversified fiber layout patterning capabilities.

<FIG> present example embodiments <NUM>, <NUM>, 1002B, <NUM>, 1004B, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of a pressure foot device <NUM> for applying an elongate fiber tow <NUM>. For example, a pressure foot device <NUM> for applying an elongate fiber tow <NUM> onto an object surface <NUM>, the device comprising: a foot surface <NUM>, for pressing the fiber tow <NUM> onto the object surface <NUM>, the foot surface <NUM> comprising a straight foot segment <NUM> for pressing the fiber tow <NUM> onto the object surface <NUM>, the straight foot segment <NUM> comprising a rear end <NUM> and a front end <NUM> that define a frontal direction Fx from the rear end to the front end; and a groove <NUM> comprising a left lip <NUM> and a right lip <NUM>, for guiding the tow to the foot surface <NUM>, the groove <NUM> defining a groove midplane 1130MP as a planar portion along the groove's mid-line <NUM> and extending until between the left lip <NUM> and the right lip <NUM> of the groove <NUM>, the groove <NUM> joining onto the front end <NUM> of the straight foot segment <NUM> and oriented at an elevation angle 1130A with respect to the straight foot segment <NUM>, wherein the groove <NUM> comprises a flared end <NUM> that joins with the foot surface <NUM>. For example, the elevation angle 1130A of a portion of the groove <NUM> is <NUM>°. For example, the groove <NUM> comprises a flared entry <NUM> at a groove entry 1130E located at the end that is opposite that of the flared end <NUM>. In some embodiments, the groove <NUM> comprises one or more enclosed portions forming, for example, a channel.

For example, the foot surface <NUM> comprises: a first toe surface <NUM> at a first side of the groove's midplane 1130MP and oriented at a first elevation angle 1161A1 and a first azimuthal angle 1161A2 offset from the frontal direction Fx; and a second toe surface <NUM> at a second side of the groove's midplane 1130MP and oriented at a second elevation angle 1162A1 and a second azimuthal angle 1162A2 offset from the frontal direction Fx, wherein the first azimuthal angle 1161A2 and the second azimuthal angle 1162A2 are comprised in a range from <NUM>° to <NUM>° with respect to the frontal direction Fx. For example, the first azimuthal angle 1161A2 and the second azimuthal angle 1162A2 are at about <NUM>° with respect to the frontal direction Fx. For example, the first toe surface <NUM> and the second toe surface <NUM> are coplanar. For example, the flared end <NUM> comprises a chamfer <NUM> with an elevation angle 1125A in a range from <NUM>° to <NUM>° with respect to the frontal direction Fx. For example, the flared end <NUM> comprises a fillet 1120F joining the groove <NUM> to the straight foot segment <NUM>. For example, the foot surface <NUM> is planar. For example, the foot surface <NUM>, viewed cross-sectionally in a Y-Z plane orthogonal to the straight foot segment <NUM>, comprises one or more raised contour portions <NUM>, <NUM> facing the object surface <NUM> that are raised in the Z-direction away from the object surface <NUM> with respect to the straight foot segment <NUM>.

For example, the pressure foot device <NUM> comprises a tow guide <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>. For example, a tow guide provides a method to guide a tow <NUM> or a tow portion, for example after it has been cut, towards the groove midplane 1130MP and towards the foot surface <NUM> as the pressure foot advances. The tow guide <NUM> provides, for example, a solution to a plurality of problems that may arise on their own or in combination. A first problem is that after a tow is cut, as the cut end 100E advances to the foot surface <NUM>, it may slam onto the surface upon emerging into the groove <NUM>. The tow guide, for example, provides a method to one or more of retain, slope down, align, and untwist the remaining tow portion leading to the cut end 100E. For example, the tow guide improves the ability of guiding the depositing a remaining portion of cut tow onto a surface, for example for guiding the tow along a curved path. A second problem is that some embodiments of the tow <NUM>, for example as a consequence of non-continuous supply, comprise a curvature that may cause a tow to disengage itself from the groove <NUM>. A third problem, is that one or more of dust and adhesive material may be entrained or formed, for example by a tow cutter assembly <NUM>, within a system <NUM> for applying an elongate tow. As the groove <NUM> provides an opening to monitor, clean, and heat one or more of the pressure foot and the tow, the tow guide provides, for example, a method to keep the groove visible and accessible while constraining the tow's motion.

For example, the tow guide is straddling the groove <NUM>. For example, the tow guide comprises a first arm or tow guide segment <NUM> along a path extending towards the frontal direction Fx from a first side 1100S1 of the pressure foot device <NUM> with respect to the groove <NUM> towards the groove midplane 1130MP and a second arm or tow guide segment <NUM> along a path extending towards the frontal direction from a second side 1100S2 of the pressure foot device with respect to the groove towards the groove midplane. For example, as illustrated in <FIG>, an upper edge 1181E of the first tow guide segment <NUM> and an upper edge 1182E of the second tow guide segment <NUM> slope downwards towards the groove midplane 1130MP and the plane of the foot surface <NUM> with an angle 1181A to the foot surface in a range between <NUM>° and <NUM>°, for example between <NUM>° and <NUM>°. For example, the slope is a ramp at a constant angle 1181A. For another example, the slope is of varying angle 1181A along the length of the upper edge 1181E, 1182E, for example a progressively shallower angle towards the groove midplane 1130MP.

For example, in the tow guide <NUM>-<NUM> as illustrated in <FIG>, the first tow guide segment <NUM> and the second tow guide segment <NUM> extend at least to within <NUM>, for example to within <NUM>, of the groove midplane 1130MP. For example, the tow guide comprises a gap in a direction orthogonal to the groove midplane 1130MP. For example, in the tow guide <NUM>-<NUM> as illustrated in <FIG>, the first tow guide segment <NUM> and the second tow guide segment <NUM> intersect the groove midplane 1130MP. For example, the tow guide comprises a gap in a direction parallel to the Z-axis, between the first tow guide segment <NUM> and the second tow guide segment <NUM>. For example, a gap provides for a method to enable one or more of pulling the tow out of, for example manually or electromechanically, and repositioning the tow into the tow guide <NUM>.

<FIG>, <FIG> present embodiments of a tow guide <NUM> that is, for example, connected at one end of each tow guide segment <NUM>, <NUM> to a support, for example to the pressure foot device <NUM>. For example, in <FIG>, the tow guide <NUM> embodiment is connected to the pressure foot <NUM> by an end of each of the tow guide segments <NUM>, <NUM>, for example with the first tow guide segment <NUM> connected to a first side of the pressure foot with respect to the groove <NUM> and the second tow guide segment <NUM> connected to a second side of the pressure foot with respect to the groove.

<FIG> and <FIG> present, for example, embodiments of a tow guide <NUM> wherein the first tow guide segment <NUM> is connected to a support <NUM>, <NUM>, <NUM>, <NUM> and the second tow guide segment <NUM> is connected at a first end to the first tow guide segment and is free-floating at a second end. For example, in <FIG> the tow guide <NUM> is connected to a hollow foot shaft <NUM>, for example connected to the pressure foot <NUM>. For example, in <FIG> the tow guide <NUM>, <NUM>-<NUM> is connected by an end 1181E of the first tow guide segment <NUM> to the pressure foot <NUM> and the second tow guide segment <NUM> is connected to the first tow guide segment, leaving its end 1182E freely floating.

For example, the tow guide <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> is elastically deflectable with respect to the groove <NUM>. For example, the tow guide comprises one or more of a cantilever spring, a coil spring, an arc spring, and a torsion spring. For example, the tow guide <NUM> is elastically deflectable wherein a deflection of <NUM> in one or more directions with respect to the groove <NUM> results from applying a force in one or more direction at a point of the tow guide located along the groove midplane 1130MP, the force being comprised in a range from <NUM> N to <NUM> N, for example from <NUM> N to <NUM> N, for example from <NUM> N to <NUM> N.

For example, the tow guide <NUM> comprises an aperture <NUM> forming an inverted arch. For example, the inverted arch is inclined towards the plane comprising the foot surface <NUM>. For example, the nadir <NUM> of the inverted arch is comprised on the groove midplane 1130MP. For example, the inverted arch is a three-pointed arch, a pointed segmental arch, a parabolic arch, a flat arch, a round arch, a segmental arch, a horseshoe arch, a pointed horseshoe arch, an inflexed arch, a three- or four-centered arch, or a shouldered arch, for example comprising a meplat. For example, the tow guide <NUM> comprises a sector of a funnel, for example a sector comprised in a range from <NUM>° to <NUM>°, for example a sector of <NUM>° minus an azimuthal sector 1150A of the the foot surface <NUM> (<FIG>). For example, the axis of revolution of the funnel's sector is comprised on the groove midplane 1130MP.

<FIG> is a perspective view of a pressure foot device <NUM> comprising one or more curved raised contour portions <NUM>, <NUM>. For example, one or more of the one or more raised contour portions <NUM>, <NUM> forms a raising curve 1171C, 1172C. <FIG> is a perspective view of a pressure foot device <NUM> comprising one or more straight raised contour portions <NUM>, <NUM>. For example, one or more of the one or more raised contour portions <NUM>, <NUM> forms a raising straight line <NUM>, <NUM>.

For example, the foot surface <NUM> comprises an azimuthal sector 1150A of a truncated hollow body of revolution the axis of which is comprised in the groove's midplane 1130MP wherein the azimuthal sector 1150A is comprised in a range from <NUM>° to <NUM>°, for example from <NUM>° to <NUM>°, for example from <NUM>° to <NUM>°, for example <NUM>°, for example <NUM>°. For example, the device <NUM> comprises a hollow foot shaft <NUM>, the axis of which is comprised on the groove's midplane 1330MP.

For example, the device comprises a foot pinion <NUM>, the axis of which is comprised on the groove's midplane 1330MP. For example, the foot pinion <NUM> comprises an orifice <NUM> on its axis of rotation, for example for passage of a fiber tow <NUM>. For example, the foot pinion <NUM> comprises one or more fixation points <NUM>, for example a rail, for adjusting the position of the pressure foot device <NUM>, for example for adjusting the position of the groove <NUM>, with respect to the foot pinion's orifice <NUM>. For example, another embodiment for a pressure foot device <NUM> is an integral part, for example formed of a single milled or molded component, comprising the features of the pressure foot device <NUM> and the pressure foot pinion <NUM>, for example formed as a pressure foot device comprising a plurality of pinion teeth forming a pinion, the axis of which is comprised in the groove's midplane 1130MP.

For example, the device comprises a foot pulley <NUM>, the axis of which is comprised on the groove's midplane 1330MP. For example, the foot pulley <NUM> comprises an orifice <NUM> on its axis of rotation, for example for passage of a fiber tow <NUM>. For example, the foot pulley <NUM> comprises one or more fixation points <NUM>, for example a rail, for adjusting the position of the pressure foot device <NUM>, for example for adjusting the position of the groove <NUM>, with respect to the foot pulley's orifice <NUM>. For example, another embodiment for a pressure foot device <NUM> is an integral part, for example formed of a single milled or molded component, comprising the features of the pressure foot device <NUM> and the pressure foot pulley <NUM>, the axis of which is comprised in the groove's midplane 1130MP.

For example, the foot surface <NUM> comprises, with respect to the front end, a first material within a first sector <NUM> that is proximal to the front end and a second material within a second sector <NUM> that is distal from the front end, wherein the thermal conductivity of the second material is at most half that of the first material. One or more of the first material and the second material comprise, for example: a steel alloy, for example a hardened steel, for example a DIN <NUM> steel, for example a DIN <NUM> steel; an alloy, for example a metal alloy, comprising one or more of: copper, aluminium, iron, nickel, tin, titanium, tungsten, vanadium, and zinc; a ceramic, a glass, and a polymer. In some embodiments, the foot surface comprises a coating, for example a coating comprising one or more of: a metal; a hardened metal; a metal oxide; a ceramic; a polymer, for example a polytetrafluoroethylene. For example, the foot surface has a Rockwell scale hardness of HRC <NUM> or greater.

<FIG> is a perspective view and <FIG> is a cross-sectional side view of a pressure foot device <NUM> comprising a heat sink <NUM>. For example, the foot surface <NUM> comprises a heat sink <NUM>. For example, the heat sink comprises a plurality of blades 1155B, for example equispaced blades. For example, the blades are blown by a source of air, for example comprising one or more ducts 1155D, for example directed towards the plurality of blades 1155B. For example, the foot surface <NUM> comprises a heat sink <NUM> that forms a surrounding second sector around a first sector <NUM> that is proximal to the groove <NUM>.

For example, the flared end <NUM> comprises a first flared end portion <NUM>-<NUM> that is proximal to the groove <NUM>, is raised from the foot surface <NUM> by a distance 1115Z, and separated by a second sector <NUM> from a heat sink portion <NUM> comprised in the foot surface <NUM>, and wherein the second sector <NUM> forms a thermally insulating portion between the first flared end portion <NUM>-<NUM> and the foot surface <NUM>. For example, the thermally insulating portion of the second sector <NUM> comprises a thermally insulating material, for example one or more of: a ceramic, a glass, a polymer, a polymer foam, an elastomer, and a sandwich comprising a foam. For example, the second sector <NUM> limits the thermal conductivity from the first flared end portion <NUM>-<NUM> to the heat sink portion <NUM> to a value less than <NUM> W/m<NUM>/K. For example, the second sector <NUM> comprises a structure comprising a plurality of ribs, for example comprising cutouts, mechanically linking first flared end portion <NUM>-<NUM> to the heat sink portion <NUM>.

<FIG> is a bottom view of a pressure foot device <NUM> comprising a groove the cross-section of which comprises one or more pairs of symmetrically opposing circular contour sectors. For example, the groove's cross-section comprises one or more pairs of symmetrically opposing circular contour sectors 1130C11, 1130C12, 1130C21, 1130C22 with respect to the midplane 1130MP, comprised at a groove depth greater or equal than that of the radius 1130MR of the greatest circular contour sectors. For example, the groove's cross-section comprises a second pair of opposing circular contour sectors 1130C21, 1130C22 that is located at a groove depth, for example along the groove midplane 1130MP, that is greater than that of a first pair of opposing circular contour sectors 1130C11, 1130C12.

<FIG> is a bottom view of a pressure foot device <NUM> comprising a groove the cross-section of which comprises one or more U-shaped groove cross-sections that scale down into the groove. For example, the groove's cross-section comprises one or more U-shaped groove cross-sections 1130U1, 1130U2 that scale down into the groove <NUM>, for example along the groove midplane 1130MP. For example, an embodiment of a U-shaped groove <NUM> comprises a semi-circular portion joining each side of the U. Other embodiments comprise for example, one or more of an elliptic, a parabolic, and a rounded portion joining each side of the U.

<FIG> is a bottom view of a pressure foot device <NUM> comprising a groove the cross-section of which comprises <NUM> or more straight sides joined by a fillet. For example, the groove <NUM> comprises a cross-section that comprises <NUM> or more straight sides 1130S1, 1130S2 joined by a fillet 1130F. For example, the <NUM> or more straight sides 1130S1, 1130S2 are arranged symmetrically with respect to the groove midplane 1130MP. For example, an embodiment of the groove's cross section forms a half-rectangle comprising rounded corners.

For example, a distance between a groove's first lip <NUM> and a groove's second lip <NUM> is comprised in a range from <NUM> to <NUM>, for example in a range from <NUM> to <NUM>.

For example, a groove <NUM> that comprises a width, for example expressed as the lip-to-ip distance 1130W between a groove's first lip <NUM> and a groove's second lip <NUM>, that is about equal to (for example by a margin of <NUM>% to <NUM>% greater, for example <NUM>% to <NUM>% greater, than the width of the tow <NUM>) the width 100W of a tow <NUM> (<FIG>) comprising a rectangular cross-section, provides a method to constrain and guide the orientation of the tow <NUM> according to the orientation of the groove's midplane 1130MP and, by extension, the orientation of the straight foot segment <NUM>. For example, the lip-to-lip distance 1130W is greater than the width 100W of the tow <NUM> by a margin comprised in a range from <NUM>% to <NUM>%, for example from <NUM>% to <NUM>%, for example from <NUM>% to <NUM>%. For example, a tow <NUM> having a width 100W of about <NUM> is conveyed in a groove <NUM> having a lip-to-lip distance 1130W in a range from <NUM> to <NUM>, for example <NUM>. For example, the width 100W of a tow <NUM> is formed and defined by the width 3531BW of a groove 3531BG of a grooved wheel 3531B (<FIG>) of a tow forming assembly <NUM> (<FIG>). For another example embodiment, a tow <NUM> having a width 100W of about <NUM> is conveyed in a groove <NUM> having a lip-to-lip distance 1130W in a range from <NUM> to <NUM>, for example <NUM>.

For example, a method that rotates the pressure foot device <NUM> around the Z-axis also rotates the tow <NUM> around the Z-axis. For example, a method <NUM>, device, or system <NUM> that rotates the tow <NUM> as it translates with respect to an object <NUM>, provides a method to, compared to a non-rotated tow, increase the adhesion surface of the tow <NUM> onto the object surface <NUM> and increase the adhesive force between the tow <NUM> and the object surface. For example, a method <NUM> for applying an elongate fiber tow (<FIG>) comprises rotating <NUM> the pressure foot device <NUM>, for example so that the angle of rotation matches the tangent 7001PT to the path of the pressure foot device <NUM> (<FIG>). For example, the method <NUM> that comprises rotating the tow <NUM> as it is applied to a curved path <NUM>-<NUM> onto an object surface <NUM> reduces the probability that the tow will unstick from the object surface <NUM> and form a shortcut with respect to the desired path for the tow. For example, the method <NUM> of rotating the tow <NUM> within a groove <NUM> that is about the same width as the tow <NUM>, prevents loss of tow positioning precision, for example cause by unplanned lateral position jumping of the tow that is, for example, observed in systems feeding and translating a tow or filament within a channel that is substantially larger than the width of the tow <NUM>.

<FIG> is a perspective view of a system <NUM> for applying an elongate fiber tow, comprising a pinion-driven pressure foot device <NUM>, a foot shaft housing <NUM> comprising one or more heat source <NUM>, and a heat exchanger housing <NUM>. <FIG> presents a cross-section of a system <NUM> for applying an elongate fiber tow <NUM> onto an object surface <NUM>, the system comprising a pressure foot device <NUM>. For example, the pressure foot device <NUM> comprises a foot surface <NUM>, for pressing the fiber tow <NUM> onto the object surface <NUM>, the foot surface <NUM> comprising a straight foot segment <NUM> for pressing the fiber tow <NUM> onto the object surface <NUM>, the straight foot segment <NUM> comprising a rear end <NUM> and a front end <NUM> that define a frontal direction Fx from rear end to front end; and a groove <NUM> comprising a left lip <NUM> and a right lip <NUM>, for guiding the tow to the foot surface <NUM>, the groove <NUM> defining a groove midplane 1130MP as a planar portion along the groove's mid-line <NUM> between the left lip <NUM> and the right lip <NUM> of the groove <NUM>, the groove <NUM> joining onto the front end <NUM> of the straight foot segment <NUM> and being oriented at an elevation angle 1130A with respect to the straight foot segment <NUM>. The elevation angle 1130A of a portion of the groove <NUM> is at <NUM>° to the foot surface <NUM>. For example, the groove <NUM> comprises a flared end <NUM> that joins with the foot surface <NUM>. For example, the system <NUM> further comprises a foot shaft housing <NUM>, characterized by a foot shaft's axis of rotation Z, defining a Z-axis, wherein the foot shaft's axis of rotation Z is orthogonal to the straight foot segment <NUM> and comprised in the groove midplane 1130MP. The pressure foot device <NUM> comprises a tow guide <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> straddling the groove <NUM> wherein the distance <NUM> from the front end <NUM> of the straight foot segment <NUM> to the tow guide <NUM> along the groove midplane 1130MP is comprised in a range from <NUM> to <NUM>.

For example, the pressure foot device <NUM> comprises a hollow foot shaft <NUM>, the axis of which is collinear with the foot shaft's axis of rotation Z and wherein a portion of the shaft forms a sliding fit within the foot shaft housing <NUM>. For example, the hollow foot shaft <NUM> comprises a through hole that is concentric with the external diameter of the hollow foot shaft <NUM>. In some examples of a hollow foot shaft <NUM>, a portion of the shaft forms a running fit within the foot shaft housing <NUM>. For example, the foot shaft housing <NUM> comprises one or more sources of heat <NUM>. A source of heat <NUM> comprises, for example, one or more of: one or more electrically resistive elements; and one or more inductive elements, for example formed as one or more coils <NUM>, <NUM>, <NUM>, <NUM>.

For example, the system <NUM> comprises a source of radiation <NUM> comprising infrared radiation directed towards the groove <NUM>. For example, the source of radiation <NUM> is comprised in a plane from the foot shaft's axis of rotation Z to the source of radiation <NUM> that is coplanar with the groove midplane 1130MP. For example, the source of radiation <NUM> comprises one or more electrically resistive elements, for example comprising one or more rods, for example oriented in a direction that is coplanar with the foot shaft's axis of rotation Z. For example, the source of radiation comprises a radiation reflector, for example oriented to reflect radiation towards one or more of the groove <NUM>, the flared end <NUM>, and the object surface <NUM>. For example, the source of radiation <NUM> comprises one or more optic fibers, for example to guide radiation emitted by one or more lasers towards one or more of the groove <NUM>, the flared end <NUM>, and the object surface <NUM>.

<FIG> are top views of a foot shaft housing <NUM> comprising one or more inductive coils as heat sources <NUM>, <NUM>, <NUM>, <NUM> to the underlying pressure foot device <NUM>. For example, the foot shaft housing <NUM> comprises one or more induction heating coils <NUM>, <NUM>, <NUM>, <NUM>. For example, the axis of one or more of the induction heating coils <NUM>, <NUM>, <NUM>, <NUM> is parallel to that of the foot shaft's axis of rotation Z.

For example, the system comprises a temperature sensor <NUM>, <NUM>, <NUM> comprised in one or more of: the foot shaft housing <NUM>; and the pressure foot device <NUM>. In some embodiments of the system <NUM>, a temperature sensor <NUM> is comprised in a heat exchanger housing <NUM>. For example, the foot shaft housing <NUM> comprises a cylindrical sleeve <NUM> that is coaxial with the foot shaft's axis of rotation Z.

For example, the system <NUM> comprises one or more pinch roller assemblies <NUM>.

<FIG> is a top view of the rollers of a pinch roller assembly <NUM> comprised in a system for applying an elongate fiber tow <NUM>. For example, one or more of the pinch roller assemblies <NUM> comprises a first roller <NUM>-<NUM> and a second roller <NUM>-<NUM>, wherein a tangent that is common to the first roller and to the second roller is collinear with the foot shaft's axis of rotation Z. For example, in some embodiments, the tangent that is common to the first roller and to the second roller is intersected by the foot shaft's axis of rotation Z.

For example, one or more of the pinch roller assemblies <NUM> comprises a first roller <NUM>-<NUM> and a second roller <NUM>-<NUM>, wherein one or more of the rollers <NUM>-<NUM>, <NUM>-<NUM> comprises a rectangular groove <NUM> in the roller's perimeter. For example, the groove's cross section intersects the foot shaft's axis of rotation Z. For example, one or more of the first roller <NUM>-<NUM> and the second roller <NUM>-<NUM> can be separated away from the other roller or brought back against the other roller by acting, for example by a user, on the roller support handle <NUM> (shown in <FIG>). For example, the rotation axis of one or more of the rollers is supported by the roller support handle <NUM>.

For example, the system <NUM> comprises: an inlet <NUM>, for example comprising one or more of an inner cylindrical geometry for receiving a tube and a funnel for guiding a filament, for example a roving or tow, for example comprising one or more folds along the longitudinal axis, for example the Z-axis; and a tubular conduit <NUM>, for example for straightening and guiding the filament from the inlet <NUM> into the groove <NUM>.

For example, the system <NUM> comprises a tow cutter assembly <NUM> comprising an orifice <NUM> and a blade <NUM>, the orifice <NUM> intersecting the foot shaft's axis of rotation Z. For example, an embodiment of a tow cutter assembly <NUM> comprises an ultrasonic cutter, for example a blade actuated at one or more ultrasonic frequencies.

For example, the system <NUM> comprises a tow cutter assembly <NUM> comprising a blade <NUM> guided by a rail <NUM> that is mechanically coupled to a rotatable <NUM> ring, the rotation axis of which is collinear with the foot shaft's axis of rotation Z. For example, the rotatable ring is coupled to a driving assembly <NUM> comprising, for example, one or more of: a gear; a pulley; and a motor <NUM>, for example a stepper motor.

For example, the system <NUM> comprises a heat exchanger housing <NUM> disposed between the foot shaft housing <NUM> and one or more of the one or more pinch roller assemblies <NUM>, the heat exchanger housing <NUM> comprising a first through hole <NUM>, the axis of which is collinear with the foot shaft's axis of rotation Z. In some embodiments of the system <NUM>, a temperature sensor <NUM> is comprised in the heat exchanger housing <NUM>. For example, the heat exchanger housing <NUM> is disposed between a tow cutter assembly <NUM> and the foot shaft housing <NUM>.

<FIG> is a top cross-section of a heat exchanger housing <NUM> comprising one or more ducts <NUM>. For example, the heat exchanger housing <NUM> comprises one or more ducts <NUM>. For example the one or more ducts <NUM> comprises one or more duct ports <NUM>, for example comprising a controllable valve or vane, for example for adjusting the flow of a fluid flowing inside the one or more ducts <NUM>. For example, the heat exchanger housing <NUM> comprises a duct <NUM> that forms a turning path of at least <NUM>° around the foot shaft's axis of rotation Z. For example, a duct forms one or more semi-circle loops around the foot shaft's axis of rotation Z. For example, the heat exchanger housing <NUM> comprises a second through hole <NUM>, the axis of which is parallel to the foot shaft's axis of rotation Z. For example, the heat exchanger housing <NUM> comprises a drive shaft <NUM> that forms a coupling with the pressure foot device <NUM>. For example, the drive shaft comprises a pinion <NUM> that is coupled with the pressure foot pinion <NUM>. For another example, as shown in <FIG>, the drive shaft comprises a pulley <NUM> that is coupled with the pressure foot pulley <NUM>.

For example, the heat exchanger housing <NUM> forms a thermally conductive contact <NUM> with a drive shaft <NUM> that forms a coupling with the pressure foot device <NUM>, wherein the contact's interfacial conductance is greater than <NUM> W/m<NUM>/K.

For example, the heat exchanger housing <NUM> comprises a tow duct <NUM>, wherein the tow duct comprises an entry portion <NUM> and an exit portion <NUM>, and wherein the exit portion's axis of symmetry is comprised in the groove midplane 1130MP.

For example, a portion of the tow duct <NUM> comprises a convergent tow duct nozzle or funnel <NUM>, the outlet <NUM>-O of the convergent tow duct nozzle being oriented towards the groove <NUM>, and wherein the axis of symmetry of the outlet <NUM>-O is comprised in the groove midplane 1130MP. For example, the tow duct <NUM> comprises an exit duct <NUM>, for example aligned with the foot shaft's axis of rotation Z, for example having an inner diameter that is inferior to that of the inner diameter of the portion of tow duct <NUM> comprised between the rollers <NUM>-<NUM>, <NUM>-<NUM> and the tow duct nozzle or funnel <NUM>. For example, the system <NUM> comprises a duct extension <NUM>, the axis of which is aligned with the pressure foot device's axis of rotation Z. For example, the duct extension is aligned with the tow duct <NUM>. In some embodiments, the duct extension passes, for example, through one or more of: the through hole <NUM>, the foot shaft housing <NUM>; and a portion of the pressure foot device <NUM>, for example a portion of the pressure foot device passing through the foot shaft housing <NUM>.

For example, the system <NUM> comprises one or more rangefinding detector assemblies <NUM> each comprising a rangefinder <NUM>, one or more of the rangefinder's measurement axes ZR being oriented along a direction parallel that of the foot shaft's axis of rotation Z, wherein the distance <NUM> from the rangefinding detector's measurement axis ZR to the foot shaft's axis of rotation Z is greater than the distance <NUM> from the foot shaft's axis of rotation Z to the straight foot segment's rear end <NUM> and less than <NUM>.

For example, one or more of the one or more rangefinding detector assemblies <NUM> comprises a translation stage <NUM>. For example, the translation stage <NUM> provides a method to adjust the position of the one or more rangefinding detector assemblies <NUM> with respect to the pressure foot device <NUM>.

For example, the system <NUM> comprises a tow forming assembly <NUM>, for example supported by a tow forming assembly chassis <NUM>. For example, the tow forming assembly chassis <NUM> comprises one or more of: a tape orienter and tensioner assembly <NUM>; a tape pre-heating assembly <NUM>; a tape heater <NUM>; a tow forming assembly <NUM>; and a tow heating assembly <NUM>. For example, the tow forming assembly <NUM> comprises one or more grooved wheels <NUM>, 3531A, 3531B wherein at least a portion of the groove's cross-section is rectangular. For example, the tow forming assembly <NUM> comprises a tape orienter and tensioner assembly <NUM>, for example comprising a wheel <NUM>, for example comprising a flat-bottomed groove, for example configured to apply a load, for example via a weight, a spring, or a servomotor, onto the tape <NUM>. For example, the tow forming assembly <NUM> comprises a tape pre-heating assembly <NUM>. For example, the tape pre-heating assembly <NUM> comprises one or more of: a first grooved wheel <NUM> comprising, for example, a flat-bottomed groove <NUM>; and a wheel cooler 3522C. For example, the wheel cooler comprises one or more of: an air blower, for example comprising an air supply and one or more orifices, for example in the tow forming assembly's chassis <NUM>; and a cooling bath, for example comprising water.

For example, the tow forming assembly <NUM> comprises a tape post-heating assembly or first tow forming assembly <NUM>. For example, the cross-section of the groove of one or more second grooved wheels 3531A, 3531B comprises a V-shaped groove entry 3531E and a rectangular-shaped groove depth 3531D. For example, the tape <NUM> is folded into a tow <NUM> at the second grooved wheel 3531A. For example, the first tow forming assembly <NUM> comprises a wheel cooler 3522C.

For example, the system <NUM> comprises one or more source of infrared radiation <NUM>, <NUM> directed towards the path of the tow <NUM>. For example, a tape-heating source of infrared radiation <NUM> is comprised between the first grooved wheel <NUM> and the second grooved wheel 3531A. For example, the tow heating assembly <NUM>, for example comprising a tow-heating source of infrared radiation <NUM>, is comprised down-tow of one or more of the second grooved wheel 3531A, 3531B, for example at a tow heating assembly <NUM> of the tow forming assembly <NUM>. For example, the tow-heating source of infrared radiation <NUM> comprises an aperture 3542A for one or more of: inserting the tow; enabling visual monitoring of the tow; and heating only a portion of the tow's periphery.

For example, the one or more source of infrared radiation <NUM>, <NUM> is connecting to an actuator assembly <NUM> the end-effecting path of which has a vector component that is orthogonal to one or more of the path of the tape <NUM> and tow <NUM>. For example, the path of the tape <NUM> or tow <NUM> is a line joining the periphery of the first grooved wheel <NUM> to the periphery of the second grooved wheel 3531A. Note, for example in some embodiments, that it is within and between the first grooved wheel <NUM> and the second grooved wheel 3531A that the tape <NUM> is converted into the tow <NUM>. At some locations of the tow forming assembly <NUM>, the tape <NUM> becomes the tow <NUM> and therefore both the words tape and tow are appropriate to describe the material comprising fibers. For example, the actuator assembly <NUM> comprises one or more of: a lever arm assembly, a pantograph assembly, and a rail assembly. For example, the one or more source of infrared radiation <NUM>, <NUM> is connecting to a guiding rail 3544R. For example, the actuator assembly <NUM> comprises an actuator <NUM>, for example a servomotor. For example, the actuator <NUM> is connected to one or more of a data bus <NUM> and a processor <NUM>. For example, the actuator <NUM> is configured to receive instructions to adjust the position, for example the distance, of the one or more source of infrared radiation <NUM>, <NUM> with respect to the tow <NUM> as a function of one or more of: the speed of the tow; the tension of the tow; and the temperature of the tow. For example, the actuator assembly has a maintenance configuration, for example providing a distance separating the source of infrared radiation <NUM>, <NUM> by a distance comprised in a range from <NUM> to <NUM> from the path of the tow, for example to enable an operator to manually insert a tow <NUM> or to clean the tow forming assembly <NUM>.

For example, the system <NUM> comprises a tow tractor assembly <NUM>. For example, the tow tractor assembly is located down-tow of the tow forming assembly's chassis <NUM>. For example, the tow tractor assembly <NUM> comprises one or more pinch roller assembly <NUM>, <NUM>, <NUM>, for example <NUM> pinch roller assemblies. For example, the one or more pinch roller assembly <NUM>, <NUM>, <NUM> is driven by a tow tractor assembly motor <NUM>. For example, tow tractor assembly <NUM> comprises one or more of: a speed sensor, for example to measure or estimate tow speed, for example as one or more of a wheel encoder or resolver mounted on one or more of the pinch roller and an optical sensor, for example monitoring the tow; a tension sensor, for example mounted on one or more of the pinch roller; and a motor power sensor, for example to estimate tension in the tow.

For example, the system <NUM> comprises a tow buffer assembly <NUM>. For example, the tow buffer assembly <NUM> comprises one or more flexible tubing assemblies comprising a first tube <NUM> and a second tube <NUM>, wherein the outer diameter of the first tube is less than the inner diameter of the second tube and wherein the first tube is slidingly inserted into the second tube. For example, the buffer assembly <NUM> wherein the outer diameter of the first tube is less than the inner diameter of the second tube enables a method wherein the first and the second tube slide, for example telescopically, with respect to each other as the tension on the tow <NUM>, that passes within the first tube <NUM> and the second tube <NUM>, successively increases and decreases as the tow <NUM> is supplied by the tow forming assembly <NUM> and demanded by the pinch wheel assembly <NUM>. For example, the first tube <NUM> and the second tube <NUM> slide into each other telescopically and form a loop <NUM>. For example, the tow entrance of the first tube <NUM> is anchored by a first fastener 3610F. For example, the tow exit of the second tube <NUM> is anchored by a second fastener 3620F. For example, one or more of the first tube <NUM> and the second tube <NUM> is constrained by a unidirectional restraint <NUM> to allow motion of the tubes <NUM>, <NUM> in a single direction, for example a loop's radial direction. For example, the unidirectional restraint <NUM> comprises one or more restraint rollers <NUM>, for example <NUM> restraint rollers <NUM>. For example, the restraint rollers <NUM> are slidingly mounted to a rail <NUM>, for example oriented in a loop's radial direction, for example a direction orthogonal to the direction at which the tow exits the tow forming assembly <NUM>, for example a vertical direction. For example, one or more of the restraint rollers <NUM> is spring-loaded along the rail's direction. In some embodiments, the unidirectional restraint <NUM> comprises a sensor, for example a position sensor, for example a strain gauge, to detect one or more of the loop's tension and geometry.

For example, the system <NUM> comprises a tow longitudinal tension detector <NUM>. For example, the tension detector <NUM> comprises for example one or more wheels, for example one or more sliders, that is configured to be in contact with the tow <NUM> at a first end and coupled to a force measurement sensor, for example a strain gauge at a second end.

For example, the system <NUM> comprises a slide head <NUM> comprising one or more axes <NUM>, <NUM>. For example, the slide head <NUM> comprises a first axis <NUM> that is orthogonal to a second axis <NUM>. For example, one or more of the one or more axes <NUM>, <NUM> is intersected by the Z-wise extended groove midplane 1130MPZ that extends the groove midplane 1130MP in the Z-direction.

For example, one or more of the one or more axes <NUM>, <NUM> comprises two orthogonal axes <NUM>, <NUM>, the intersection point of which is about on the Z-wise extended groove midplane 1130MPZ that extends the groove midplane 1130MP in the Z-direction. For example, the intersection point is comprised within a radius from the Z-axis that is equal to <NUM> diameters of the axis of greatest diameter.

For example, the system <NUM> comprises a support chassis comprising a tubular clamp <NUM>, the axis of which is parallel to the foot shaft's axis of rotation Z.

For example, the system <NUM> comprises one or more of a pinch roller motor <NUM> coupled to one or more pinch roller assemblies <NUM>, a tow cutter motor <NUM> coupled to a tow cutter assembly <NUM>, and a foot rotation motor <NUM> coupled to the pressure foot device <NUM>.

For example, the system <NUM> comprises a dispenser nozzle outlet <NUM> for dispensing a thermoplastic material onto the object surface <NUM>. For example, the dispenser nozzle outlet is adapted to dispense a thermoplastic material that comprises one or more of: a metal, for example a metal powder; chopped fibers, for example comprising chopped carbon fibers; a silicate, for example sand; a ceramic; a powder, for example a carbon black powder; a silicone; a foam, for example a urethane, a polyurethane, or a polystyrene foam; and an elastomer.

For example, the system <NUM> comprises a dispenser nozzle assembly <NUM>. For example, the dispenser nozzle assembly <NUM> comprises: an inlet <NUM>, for example comprising one or more of an inner cylindrical geometry for receiving a tube and a funnel for guiding a filament, for example a thermoplastic material filament; one or more rollers <NUM>-<NUM>, <NUM>-<NUM>, for example comprising a groove <NUM> in the roller's perimeter, and driven by a pinch roller motor <NUM>; a tubular conduit <NUM>, for example for straightening and guiding the material filament from the inlet <NUM> into the groove <NUM>; and a duct <NUM>, for example for guiding the material filament to the nozzle <NUM>.

For example, the system <NUM> comprises a dispenser nozzle extension actuator <NUM> to adjust the Z-axis position of the dispenser nozzle's outlet <NUM>.

For example, the Z-axis position of the dispenser nozzle's outlet <NUM> is offset from the Z-axis position of the straight foot segment <NUM> by an offset <NUM> comprised in a range from - <NUM> to +<NUM>.

<FIG> is a perspective view of a system <NUM> for applying an elongate fiber tow mounted on a robotic manipulator <NUM>. For example, the system <NUM> comprises a robotic support <NUM> to configure one or more of the position and speed of the pressure foot device <NUM> at one or more spatial positions (XF, YF, ZF) and one or more spatial orientations (φF, θF, ψF). For example, the robotic support comprises one or more motor <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to actuate one or more joint for configuring the pressure foot device, placed for example at a robot's end-effector location, into a spatial position and orientation.

<FIG> presents a block diagram of a computer system <NUM>. For example, the system <NUM> comprises the computer system <NUM>. For example, the computer system <NUM> comprises one or more of a digital processor <NUM>, a computer-readable non-volatile storage device or medium <NUM>, a user interface device <NUM>, a data bus <NUM> connected to one or more sensor <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and one or more actuator <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> comprised in the system, a memory <NUM>, and a communication interface device <NUM> for transferring data between one or more of the digital processor <NUM>, the computer-readable non-volatile storage device <NUM>, the data bus <NUM>, the user interface device <NUM>, and one or more external systems <NUM> external to the system comprising one or more of a processor, a storage device, a user interface, an actuator, and a sensor.

For example, the one or more sensor comprises one or more of: a rangefinder <NUM> comprising a measurement axis oriented along a direction parallel that of the foot shaft's axis of rotation Z, a tow longitudinal tension detector <NUM>, a temperature sensor <NUM> comprised in the foot shaft housing <NUM>, and a temperature sensor <NUM> comprised in a heat exchanger housing <NUM>. For example, the one or more actuator <NUM> comprises one or more of: a foot rotation motor <NUM>, a pinch roller motor <NUM>, one or more induction heating coils <NUM>, <NUM>, <NUM>, <NUM> of the pressure foot device <NUM>, and a tow cutter assembly motor <NUM>.

<FIG> presents a block diagram of a method <NUM>, for example a computer-based method comprising computer-readable instructions stored in a non-transitory storage medium, for applying an elongate fiber tow <NUM> onto an object surface <NUM>, the method comprising: translating <NUM> an elongate fiber tow <NUM> into a groove <NUM> of a pressure foot device <NUM> unto a foot surface <NUM> of the pressure foot device <NUM>, the groove <NUM> comprising a left lip <NUM>, a right lip <NUM>, and defining a groove midplane 1130MP along the groove's mid-line <NUM> and extending until between the left lip <NUM> and the right lip <NUM> of the groove <NUM>; guiding <NUM> the fiber tow to a straight foot segment <NUM> comprised in the foot surface <NUM> of the pressure foot device, wherein the straight foot segment <NUM> comprises a rear end <NUM> and a front end <NUM> that define a frontal direction Fx from the rear end to the front end, and the groove <NUM> joining onto the front end of the straight foot segment <NUM>; and pressing <NUM> the fiber tow between the straight foot segment and the object surface <NUM>.

For example, the method comprises guiding <NUM> the fiber tow <NUM> within the groove <NUM> to a flared end <NUM> of the groove and curving <NUM> the fiber tow around the flared end of the groove to the straight foot segment <NUM>. For example, the method comprises guiding <NUM> the fiber tow <NUM> within the groove <NUM> wherein guiding the fiber tow comprises sliding the fiber tow against the tow guide <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>. For example, the method comprises sliding the fiber tow <NUM> against the tow guide <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> comprises sliding the fiber tow against one or more tow guide segment <NUM>, <NUM>. For example, the fiber tow <NUM> within the groove <NUM> comprises a cut end 100E. For example, the method comprises intercepting the cut end 100E of the fiber tow <NUM> with the tow guide <NUM>, for example as the cut end emerges into the groove <NUM>. For example, the intercepting comprises aligning the cut end 100E into the groove midplane by way of the cut end 100E sliding against the inverted arch or the funnel of the tow guide.

For example, one or more of translating <NUM>, guiding <NUM>, curving <NUM>, and pressing <NUM> comprises heating <NUM> the fiber tow <NUM>. For example, pressing <NUM> comprises cooling <NUM> the fiber tow <NUM>. For example a method of cooling the fiber tow <NUM> comprises contacting the fiber tow <NUM>, for example pressing the fiber tow <NUM> with the distal portion (with respect to the groove <NUM>) or the heat sink portion <NUM> of the pressure foot device <NUM>. For example, pressing <NUM> comprises a first step that comprises heating <NUM> the fiber tow <NUM> and a second step that comprises cooling <NUM> the fiber tow <NUM>.

For example, the method <NUM> comprises adjusting electrical power <NUM> delivered to one or more sources of heat <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> for heating the fiber tow <NUM>.

For example, the method <NUM> comprises rotating <NUM> the pressure foot device <NUM> around an axis of rotation Z that is orthogonal to the straight foot segment <NUM> and comprised within the groove midplane 1130MP. For example, the method <NUM> comprises translating <NUM> the pressure foot device <NUM>. For example, the method <NUM> comprises simultaneously translating <NUM> and rotating <NUM> the pressure foot device <NUM> wherein the rotating comprises orienting the straight foot segment <NUM> away from a tangent to the translational path for one or more excursion by an angle comprised in a range from <NUM>° to <NUM>°. For example, orienting the straight foot segment <NUM> away from a tangent to the translational path comprises oscillating the orientation in a range from <NUM>° to <NUM>° one or more of left and right of the path, for example from <NUM>° to <NUM>°. For example the oscillation comprises one or more of a sinewave, a square, a triangle, and a sawtooth oscillation. For example, each of the one or more excursion lasts for a duration comprised between <NUM> and <NUM>. For example, the duration of an excursion is controlled, for example by the processor <NUM> according to instructions recorded on a non-volatile storage medium <NUM>, as a function of one or more of tow speed and relative speed of the pressure foot device <NUM> with respect to the object surface <NUM>.

<FIG> is a top view of an object <NUM> comprising a layer of tows <NUM> comprising a plurality of fiber tow segments <NUM>, <NUM>, <NUM>. For example, the method <NUM> comprises one or more of translating <NUM> and rotating <NUM> the pressure foot device <NUM> along a path <NUM>, <NUM>, <NUM> from a path start <NUM>-S to a path end <NUM>-E, wherein the straight foot segment <NUM> is collinear with a tangent 7001T to the path of the pressure foot device <NUM> and the point of tangency 7001PT to the path <NUM> is comprised within the groove midplane 1130MP. For example, the method <NUM> comprises simultaneous translation and rotation. A method to form a spiral path <NUM> comprises forming one or more paths, for example successively arranged paths <NUM>, <NUM>, <NUM>, that form a spiral arrangement. For example, the method <NUM> comprises forming an internal region <NUM>, also called an infill <NUM>, that fills the area or volume, for example in a plurality of stacked rows or layers <NUM>, comprised within one or more of the external contour formed by the path <NUM>, <NUM>, <NUM> of the object <NUM>.

For example, the fiber tow <NUM> is translated within the groove <NUM> at a speed equal to the speed at which the point of tangency 7001PT to the path <NUM> translates along the path.

For example, the method <NUM> comprises forming a cut <NUM> in the fiber tow <NUM> at the location <NUM>-E where the radius of curvature of the path is one or more of: less than <NUM>; less than <NUM>; and less than <NUM>. For example, the radius of curvature of the path is a path that is planned by one or more path instructions, for example generated by a computer-based path-planning system. For example, the path is segmented at locations where the path plan comprises a radius of curvature that is below a threshold, for example a threshold of one or more of: less than <NUM>; less than <NUM>; and less than <NUM>.

For example, the method <NUM> comprises actuating <NUM> a tow cutter assembly <NUM> at a location <NUM>-C, <NUM>-C, <NUM>-C along the path <NUM>, <NUM>, <NUM> that is ahead of the path end by a path length <NUM> equal to the length <NUM> of fiber tow from the tow cutter assembly's blade <NUM> to the front end <NUM> of the straight foot segment <NUM>.

For example, the method <NUM> comprises unwinding <NUM> the tow <NUM> wherein unwinding comprises rotating <NUM> the pressure foot device <NUM>.

For example, the method <NUM> comprises forming a measurement <NUM> of a distance <NUM> between the straight foot segment <NUM> and the object surface <NUM>. For example the distance corresponds to a height along the Z-axis.

For example, the method <NUM> comprises adjusting <NUM> a distance <NUM> between the straight foot segment <NUM> and the object surface <NUM>. For example, adjusting a distance <NUM> is a function of one or more measurements of a distance from the object surface <NUM>, for example acquired with one or more of the rangefinding detector assemblies <NUM>. For example, the method <NUM> comprises adjusting <NUM> a distance <NUM> between a dispenser nozzle <NUM> and the object surface <NUM>. For example, adjusting a distance <NUM> is a function of one or more measurements of a distance from the object surface <NUM>, for example acquired with one or more of the rangefinding detector assemblies <NUM>. For example, the method <NUM> comprises adjusting <NUM> a distance offset <NUM>, for example along the Z-axis, of the dispenser nozzle <NUM> with respect to the object surface <NUM> as a function of a distance <NUM> between the straight foot segment <NUM> and the object surface <NUM>.

For example, the method <NUM> comprises: translating <NUM> the fiber tow <NUM> within the groove <NUM> by a length <NUM> comprised in a range from <NUM> to <NUM>; and guiding the pressure foot device <NUM> along a landing trajectory <NUM>, <NUM>, <NUM> onto the object surface <NUM>.

For example, the method <NUM> comprises forming <NUM> one or more folds along the length of the fiber tow <NUM> by passing a fiber tape <NUM> within one or more grooves comprising a rectangular cross-section. For example, passing comprises engaging the fiber tape <NUM> into and out of one or more grooves, for example a static groove, for example the groove of one or more grooved wheels. For example, the passing results in one or more of: aligning the tape <NUM>; compressing the tape <NUM>; and folding the tape <NUM>, for example into a tow <NUM>.

For example, the forming <NUM> one or more folds comprises passing the fiber tape <NUM> within one or more grooves <NUM>, 3531AG, 3531BG that are comprised on one or more grooved wheels <NUM>, 3531A, 3531B.

For example, the method <NUM> comprises acquiring <NUM> measurements of the longitudinal tension of the fiber tow <NUM> from a tow longitudinal tension detector <NUM>.

For example, the method <NUM> comprises adjusting <NUM> the speed of the translating <NUM> of the tow <NUM> as a function of measurements of the longitudinal tension of the fiber tow <NUM> from a tow longitudinal tension detector <NUM>.

<FIG> presents a block diagram of instructions <NUM> for a method comprised in a computer-readable non-volatile storage device <NUM>. For example, the instructions <NUM> or parts thereof, are representative of a method, for example a computer-implemented method. For example, the computer-readable non-volatile storage device <NUM> comprises executable instructions <NUM> that, when executed by one or more processors <NUM> of a system <NUM> for applying an elongate fiber tow <NUM> onto an object surface <NUM>, cause the system <NUM> to at least: a) command <NUM> one or more of position and speed of a first tow entrainment motor <NUM>, causing an elongate fiber tow <NUM> to translate along a groove <NUM> of the pressure foot device <NUM>; and b) command <NUM> one or more of position and speed of a second motor <NUM> coupled to a pressure foot device <NUM> and causing the pressure foot device to rotate. For example, the pressure foot device <NUM> rotates around an axis of rotation Z that is orthogonal to the straight foot segment <NUM> and comprised within a groove midplane 1130MP along a groove's mid-line <NUM> comprised between a left lip <NUM> and a right lip <NUM> of the groove.

For example, the instructions <NUM> comprise instructions for a method wherein the speed at which the first motor <NUM> is commanded <NUM> is a function of the speed at which the second motor <NUM> is commanded <NUM>.

For example, the instructions <NUM> further comprise instructions for a method to command <NUM> a third motor <NUM> coupled to a tow cutter assembly <NUM> and causing the tow cutter assembly to displace a blade <NUM> from a first position to a second position. For example, the instructions <NUM> comprise instructions <NUM> to command a cut in the tow as a function of the curvature of the path <NUM>, <NUM>, <NUM> of the tow, for example at a point of tangency 7001PT (see <FIG>). For example, the cut is commanded upon reaching a cut position <NUM>-C, <NUM>-C, <NUM>-C to form a complete cut across the entirety of the tow's cross-section. For example, the cut is commanded to form a partial cut across a portion of the tow's cross-section. For example, the extent of the cut across the tow's cross-section is a function, for example a linear function, of the path's radius of curvature, for example at a point of tangency 7001PT.

For example, the instructions <NUM> comprise instructions for a method to adjust the speed <NUM> of the first motor <NUM> as a function of a command sent to the third motor <NUM>.

For example, the instructions <NUM> comprise instructions for a method to acquire <NUM> rangefinder measurement data from one or more rangefinding detector assemblies <NUM>.

For example, the instructions <NUM> comprise instructions for a method to adjust <NUM> the speed of the first motor <NUM> as a function of measurements acquired from the one or more rangefinding detector assemblies <NUM>.

For example, the instructions <NUM> comprise instructions for a method to acquire <NUM> measurement data from one or more tow longitudinal tension detectors <NUM>.

For example, the instructions <NUM> comprise instructions for a method to adjust <NUM> the speed of the first motor <NUM> as a function of measurements acquired from one or more of the one or more tow longitudinal tension detectors <NUM>.

For example, the instructions <NUM> comprise instructions for a method to adjust <NUM> the relative speed of one or more first motors <NUM>, <NUM> as a function of measurements acquired from one or more of one or more tow longitudinal tension detectors <NUM>.

For example, the instructions <NUM> comprise instructions for a method to adjust <NUM> infrared radiation power of one or more of: one or more source of infrared radiation <NUM>, <NUM>, <NUM>; and one or more sources of heat <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. For example, the instructions to adjust <NUM> infrared radiation power comprised adjusting an electrical power supply, for example in one or more of voltage, current, and duty cycle. For example, the instructions <NUM> comprise instructions to adjust <NUM> tow cooling. For example, one or more of the instructions to adjust <NUM> infrared radiation power and the instructions to adjust <NUM> tow cooling comprise instructions to adjust as a function of one or more of: tow tension measurement; tow translation speed; the speed of one or more motors <NUM>, <NUM>, <NUM>; the speed of one or more wheels <NUM>, <NUM>; one or more tow cross-sectional dimension; one or more thermoplastic material cross-sectional dimension; the rotational speed of one or more rollers <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>; the temperature measured by one or more temperature sensor <NUM>, <NUM>, <NUM>; a relative amount of thermoplastic material comprised in a tow, for example in a tow cross-section; and an ambient temperature measurement. For example, the instructions to adjust <NUM> tow cooling comprise instructions to adjust one or more of: the flow rate of a cooling fluid, for example of a cooling fluid flowing inside the heat exchanger housing <NUM>, for example by sending one or more commands to one or more flow control devices, for example a valve or a vane, for example comprised in the one or more ports <NUM>.

For example, the instructions <NUM> comprise instructions to store <NUM> one or more numerical toolpath instructions <NUM>-S, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-E, <NUM>-S, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-E, <NUM>-S, <NUM>-<NUM> comprising one or more of position and orientation of the pressure foot device <NUM>.

For example, the instructions <NUM> comprise instructions for a method to insert <NUM> one or more commands for a third motor <NUM> coupled to a tow cutter assembly <NUM> into the numerical toolpath instructions <NUM>-S, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-E, <NUM>-S, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-E, <NUM>-S, <NUM>-<NUM> as a function of one or more of a path length and one or more path curvatures.

For example, the instructions <NUM> comprise instructions for a method to insert <NUM> one or more instructions to command unwinding <NUM> of the tow <NUM>, the instructions comprising commands to actuate the second motor <NUM>.

<FIG> is a top view of a system <NUM> for applying an elongate fiber tow comprised in an X-Y gantry <NUM> that further comprises a Z-wise actuated object support <NUM>. For example, the gantry <NUM> comprises an X-motor <NUM> for translating one or more of the pressure foot device <NUM> and the system <NUM> in the X-direction and a Y-motor <NUM> for translating in the Y-direction. For example, the gantry <NUM> comprises a Z-motor <NUM> for actuating the object support <NUM> in the Z-direction. For example, the instructions <NUM> comprise instructions for a method to command <NUM> one or more motors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to configure one or more of the position and speed of the pressure foot device <NUM> at one or more spatial positional coordinates XF, YF, ZF and one or more spatial orientation coordinates.

For example, the instructions <NUM> comprise instructions for a method to adjust <NUM> the distance <NUM> between the straight foot segment <NUM> and the object surface <NUM>, for example by commanding one or more motors <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to configure one or more of the position (XF, YF, ZF; φF, θF, ψF) and speed of the pressure foot device as a function of measurements acquired from one or more rangefinding detector assemblies <NUM>. For example, adjusting a distance <NUM> comprises instructions wherein the distance is a function of one or more measurement data of a distance from the object surface <NUM>, for example data acquired from one or more of the rangefinding detector assemblies <NUM>.

For example, the instructions <NUM> comprise instructions <NUM> for a method to adjust the distance <NUM> between the straight foot segment <NUM> along the axis of rotation Z and the object surface <NUM> to a value comprised in a range from <NUM> to <NUM>. For example, the value is comprised in a range from <NUM> to <NUM>, for example from <NUM> to <NUM>, for example <NUM>.

For example, the instructions <NUM> comprise instructions <NUM> for a method for translating and rotating the pressure foot device <NUM> along a path <NUM>, <NUM>, <NUM> from a path start <NUM>-S, <NUM>-S to a path end <NUM>-E, <NUM>-E, wherein the second motor <NUM> is commanded so that the straight foot segment <NUM> remains collinear with the local tangent 7001T to the path <NUM>, <NUM>, <NUM> of the pressure foot device <NUM> and the point of tangency 7001PT remains comprised within a segment extending from the straight foot segment's front end <NUM> into the length of the groove's mid-line <NUM>. For example, the translating and the rotating are simultaneous.

For example, the instructions <NUM> comprise instructions <NUM> for a method to adjust the distance <NUM> between the nozzle <NUM> and the object surface <NUM>. For example, the instructions <NUM> to adjust the distance <NUM> are a function of one or more of: the distance <NUM> between the nozzle <NUM> and the object surface <NUM>; the offset, for example along one or more of the X-, the Y- and the Z-axis, of the nozzle <NUM> with respect to the pressure foot device <NUM>, for example the Z-axis through the axis of rotation of the pressure foot device; the three-dimensional geometrical characteristics of the object surface; the speed of one or more of the pressure foot device <NUM> and the nozzle <NUM> with respect to the object surface <NUM>; and the three-dimensional geometrical characteristics of the path <NUM>, <NUM>, <NUM>, for example characterized by the curvature of a curved portion of the path comprised between two straight portions in one or more of the X-, Y-, and Z- dimensions, for example at the point of tangency 7001PT at maximum curvature of the curved portion. For example, forming a path comprising a portion comprising one or more curve or curved portion comprises decreasing the distance <NUM> between the nozzle <NUM> and the object surface <NUM> within the curved portion in comparison with the distance <NUM> in a straight portion, for example as a function of speed, for example comprising a rule that comprises a linear function of speed.

For example, the instructions <NUM> comprise instructions <NUM> for a method to adjust the distance offset, for example along one or more of the X-, the Y- and the Z-axis, between the pressure foot device <NUM> and the nozzle <NUM>. For example, the instructions <NUM> to adjust the distance offset are a function of the three-dimensional geometrical characteristics of the path <NUM>, <NUM>, <NUM>, for example to follow changes in elevation in a path, for example to maintain a constant height of the nozzle <NUM> with respect to the object surface <NUM>.

For example, the instructions <NUM> comprise instructions <NUM> for a method to guide the pressure foot device <NUM> along a landing trajectory <NUM>, <NUM> onto the object surface <NUM>. The landing trajectory comprises, for example, a trajectory portion <NUM> that is parallel to the object surface <NUM>, for example at a distance or altitude <NUM> with respect to the object surface <NUM> that is equal to that of the thickness <NUM> of a pressed filament or folded tow, for example comprised in a range from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>. For example, the landing trajectory reaches a distance or altitude with respect to the object surface <NUM> prior to the foot shaft's axis of rotation Z being brought over the object surface <NUM>. For example, the landing trajectory comprises a round out <NUM> to, for example, blend a descending trajectory <NUM>, for example a straight line descending trajectory, towards the object surface with a trajectory portion that is parallel to the object surface. For example, a tangent, for example prior to the round out <NUM>, of the descending trajectory <NUM> forms an angle with respect to the object surface <NUM> comprised in a range from <NUM>° to <NUM>°, for example from <NUM>° to <NUM>°, for example from <NUM>° to <NUM>°. For example, the landing trajectory is commanded with the rangefinder <NUM> positioned ahead of the pressure foot device <NUM>. For example, the landing trajectory is initiated from an initial approach height <NUM> comprised in a range from <NUM> to <NUM>, for example from <NUM> to <NUM> with respect to the object surface. For example, the instructions <NUM> to guide the pressure foot device along a landing trajectory comprise instruction to wind out an initial tow length <NUM>, for example for anchoring the tow to the surface, beyond the pressure foot device's foot surface <NUM>. For example, the initial tow length <NUM> has a range from <NUM> to <NUM>, for example from <NUM> to <NUM>, for example from <NUM> to <NUM>, for example from <NUM> to <NUM>.

For example, the instructions <NUM> comprise instructions <NUM> to command one or more motors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to configure one or more of the position and speed of a dispenser nozzle <NUM> at one or more spatial positional coordinates (XF, YF, ZF) and one or more spatial orientation coordinates (φF, θF, ΨF).

Claim 1:
A pressure foot device (<NUM>) for applying an elongate fiber tow (<NUM>) onto an object surface (<NUM>), the device comprising:
a foot surface (<NUM>) comprising a straight foot segment (<NUM>) configured to press the fiber tow (<NUM>) onto the object surface (<NUM>), the straight foot segment (<NUM>) having a rear end (<NUM>) and a front end (<NUM>) that define a frontal direction (Fx) from the rear end to the front end;
characterised in that
the device further comprises a groove (<NUM>), wherein an elevation angle (1130A) of a portion of the groove (<NUM>) is at <NUM>° to the foot surface (<NUM>), the groove comprising a left lip (<NUM>) and a right lip (<NUM>), configured to guide the fiber tow to the foot surface (<NUM>), the groove (<NUM>) defining a groove midplane (1130MP) as a planar portion along a mid-line (<NUM>) of the groove and extending until between the left lip (<NUM>) and the right lip (<NUM>) of the groove (<NUM>), the groove (<NUM>) joining onto the front end (<NUM>) of the straight foot segment (<NUM>), and
a tow guide (<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>) straddling the groove (<NUM>) wherein a distance (<NUM>) from the front end (<NUM>) of the straight foot segment (<NUM>) to the tow guide (<NUM>) along the groove midplane (1130MP) is in a range from <NUM> to <NUM>.