Patent Description:
Components made from thermoplastic materials are increasingly in demand in the aircraft and other industries as a result of the wide-ranging advantages of the materials. Thermoplastic materials can be used to form lightweight and high-strength structures having complex shapes. In addition, thermoplastic materials, as compared to thermoset materials, offer practically infinite shelf life, faster cycle time, the ability to be recycled/reformed, improved damage tolerance properties, as well as moisture and chemical resistance.

Currently available welding processes include using a single structure to hold the to be welded thermoplastic components together during the welding process. While acceptable, such a device as a means to hold thermoplastic components together is less than ideal. For example, very often a single device that extends across the weld line will obscure the operator's vision of the welding point and inhibit or prevent sensors (e.g., thermal sensors, thermal cameras, etc.) from sensing the welding point. What is needed is an improved method and/or system for holding thermoplastic components together during the welding process, and one that does not obscure sensing the welding process or impede a line of sight inspection technique.

<CIT> discloses a hot air welder for welding roofing material by the use of hot air provided by a shaped delivery port, the welder having a pressure wheel behind the port for rolling over the overlapped joint of the roofing material.

<CIT> discloses a method for connecting material webs disposed with overlapping edges wherein a welding unit (known hot-air or hot-wedge welding devices) is guided along the overlap zone of the material webs to be connected.

According to an aspect of the present invention, a system for welding thermoplastic components along a weld line is provided. The system includes a component positioning system and a welding subsystem. The component positioning system includes a trailing force applicator having a first lateral side trailing force applicator disposed on a first lateral side of the weld line and a second lateral side trailing force applicator disposed on a second lateral side of the weld line. The welding subsystem is configured to weld the thermoplastic components together at a weld zone. The welding subsystem includes a probe. The first lateral side trailing force applicator and the second lateral side trailing force applicator are laterally spaced apart from the weld zone. At least a portion of the first lateral side trailing force applicator and at least a portion of the second lateral side trailing force applicator are disposed aft of the weld zone. The system is configured so that during welding the first lateral side trailing force applicator, the second lateral side trailing force applicator, and the welding subsystem probe are moved relative to the thermoplastic components, or the thermoplastic components are moved relative to the first lateral side trailing force applicator, the second lateral side trailing force applicator, and the welding subsystem probe.

According to another aspect of the present invention, a method for welding thermoplastic components along a weld line is provided. The method includes: a) disposing a first lateral side trailing force applicator disposed on a first lateral side of the weld line and a second lateral side trailing force applicator on a second lateral side of the weld line; the first lateral side trailing force applicator and the second lateral side trailing force applicator are laterally spaced apart from the weld zone, and at least a portion of the first lateral side trailing force applicator and at least a portion of the second lateral side trailing force applicator are disposed aft of a weld zone; b) welding the thermoplastic components together at the weld zone using a welding subsystem having a probe; and c) during welding, moving the first lateral side trailing force applicator, the second lateral side trailing force applicator, and the welding subsystem probe relative to the thermoplastic components, or moving the thermoplastic components relative to the first lateral side trailing force applicator, the second lateral side trailing force applicator, and the welding subsystem probe.

In any of the aspects or embodiments described above and herein, at least one of the first lateral side trailing force applicator or the second lateral side trailing force applicator may include at least one roller configured for contact with the thermoplastic components.

In any of the aspects or embodiments described above and herein, a biasing structure may bias the at least one roller into said contact with the thermoplastic components. The biasing structure may be pneumatically actuated.

In any of the aspects or embodiments described above and herein, at least one of the first lateral side trailing force applicator or the second lateral side trailing force applicator may include a plurality of rollers mounted on a carriage.

In any of the aspects or embodiments described above and herein, at least one of the first lateral side trailing force applicator or the second lateral side trailing force applicator may include a rotatable belt assembly having a belt configured for contact with the thermoplastic components.

In any of the aspects or embodiments described above and herein, at least one of the first lateral side trailing force applicator or the second lateral side trailing force applicator may be disposed aft of the weld zone.

In any of the aspects or embodiments described above and herein, the belt assembly may be configured to contact the thermoplastic components over an engagement distance. The engagement distance may be long enough such that solidification of the weld zone occurs prior to the weld zone traveling aft of the first lateral side trailing force applicator and the second lateral side trailing force applicator.

In any of the aspects or embodiments described above and herein, the rotatable belt assembly may include a forward support wheel, an aft support wheel, and a plurality of intermediary support wheels disposed between the forward support wheel and the aft support wheel. The forward support wheel, the aft support wheel, and the intermediary support wheels may be disposed to contact an interior surface of the belt. The intermediary support wheels may be biased against the interior surface of the belt.

In any of the aspects or embodiments described above and herein, a biasing structure may bias the belt assembly into contact with the thermoplastic components. The biasing structure may be pneumatically actuated.

In any of the aspects or embodiments described above and herein, the component positioning system may further include a leading force applicator having a first lateral side leading force applicator disposed on the first lateral side of the weld line and a second lateral side leading force applicator disposed on the second lateral side of the weld line. The first lateral side leading force applicator and the second lateral side leading force applicator may be laterally spaced apart from the weld zone, and the first lateral side leading force applicator and the second lateral side leading force applicator may be disposed forward of the weld zone.

In any of the aspects or embodiments described above and herein, at least one of the first lateral side leading force applicator or the second lateral side leading force applicator may include at least one roller configured for contact with the thermoplastic components. The at least one of the first lateral side trailing force applicator or the second lateral side trailing force applicator may comprise a plurality of rollers mounted on a carriage.

In any of the aspects or embodiments described above and herein, at least one of the first lateral side leading force applicator or the second lateral side leading force applicator may include a rotatable belt assembly having a belt configured for contact with the thermoplastic components.

In any of the aspects or embodiments described above and herein, the welding subsystem may be an induction welding subsystem.

In any of the aspects or embodiments described above and herein, the thermoplastic plastic components may include a thermoplastic material and electrically conductive elements.

For example, aspects and/or embodiments of the present invention may include any one or more of the individual features or elements disclosed above and/or below alone or in any combination thereof.

Components made from thermoplastic composite materials are utilized in a variety of different applications, including but not limited to aircraft components. In the manufacture of such components, it is often necessary to join two thermoplastic components together using an induction welding process to form a single component. The need for dimensional accuracy makes it important to properly position the components prior to welding and also to maintain component positioning for a period of time after the welding is performed to ensure no distortion or failure of the weld occurs as the weld zone cools. The present disclosure provides an improved system and method for joining thermoplastic components together.

Referring to <FIG>, the present disclosure system <NUM> includes a component positioning subsystem <NUM> and a thermoplastic component welding subsystem <NUM>. In the thermoplastic component welding process, the thermoplastic components <NUM> to be joined are either moved and the welding subsystem <NUM> remains static, or the thermoplastic components <NUM> to be joined are held static and the system is moved, or some combination thereof. To facilitate such relative movement, in some embodiments, the present disclosure system <NUM> may include an actuation system (e.g., robotics) operable to move elements of the component positioning subsystem <NUM> and the induction welding subsystem <NUM> relative to the thermoplastic components <NUM> to be joined. The term "weld line" (weld line <NUM>) is used herein to refer to a dynamic line defined by the weld zone <NUM> as the thermoplastic components <NUM> are welded and the thermoplastic components <NUM> and/or the system components are moved relative to one another.

The term "thermoplastic component" as used herein includes components comprised partially or entirely of a thermoplastic material. In some embodiments, electrically conductive elements (e.g., carbon fibers or other electrically conductive fibers, etc.) may be incorporated into the thermoplastic material. As indicated above, thermoplastic components <NUM> may be used in a wide variety of different applications that dictate different mechanical strength requirements, rigidity or flexibility requirements, thermal environment requirements, or the like, or any combination thereof. Hence, the material comprising the thermoplastic component is chosen to satisfy those requirements. Components used to produce aircraft structures (e.g., fuselage, nacelle, etc.) are a non-limiting example of a thermoplastic component. Non-limiting examples of a thermoplastic material that may be welded according to the present disclosure include low melt (LM) polyaryletherketone ("PAEK") and polyether ether ketone ("PEEK"). The present disclosure method may be utilized with a variety of different thermoplastic materials and is therefore not limited to any particular thermoplastic material.

In some embodiments, the thermoplastic component welding subsystem <NUM> may include an induction welding probe <NUM> having a head <NUM> disposed at a distal end. The head <NUM> includes one or more induction coils that may be selectively energized with a radio-frequency electric current produced from a power source <NUM>. The radio-frequency electric current passing through the induction coil(s) produces a high-frequency electromagnetic field. The electromagnetic field(s) produced by the induction coil(s) act on electrically conductive elements (e.g., carbon fibers or other electrically conductive fibers, etc.) that may be disposed within the thermoplastic components <NUM> to be joined to produce magnetically induced currents ("eddy currents") within the electrically conductive elements. Electrical resistance produced within the electrically conductive elements as a result of the induced currents produces resistive heating utilized in the component <NUM> joining process (i.e., the "welding process").

The induction welding probe <NUM> (and the radio-frequency electric current power source <NUM>) may be controlled to produce the desired electromagnetic field(s) and related degree of resistive heating for the component welding process. Component characteristics such as the particular type of thermoplastic material, the thickness of the components to be welded, and the like often dictate welding parameters such as the amount of resistive heat required to weld the thermoplastic components <NUM>, the depth of the melt zone, etc. Controlling the induction welding process in a desired manner is not, however, always an easy task and the need to repeatably produce an acceptable weld is important. Embodiments of the present disclosure may include one or more sensors <NUM> operable to sense the weld zone <NUM> to monitor the welding process. Non-limiting examples of such sensors <NUM> include temperature sensors that operate by being in close proximity to the weld zone <NUM>, or temperature sensors that optically sense the weld zone <NUM> but require line-of-sight access to the weld zone <NUM> (e.g., thermal cameras, etc.). As will be described below, the present disclosure embodiments permit advantageous sensor access to the component weld zone <NUM>.

Referring to <FIG>, embodiments of the component positioning subsystem <NUM> includes a plurality of force applicators <NUM> configured to apply a force to a surface of the thermoplastic components <NUM> to be joined. The force applicators <NUM> operate to position the thermoplastic components <NUM> during the welding process to facilitate achieving the desired weld. One or more of the force applicators <NUM> may be disposed at a "trailing" position (e.g., see <FIG>). These force applicators may be referred to as "trailing force applicators 40T". The term "trailing" as used herein refers to a position aft of the position where welding occurs; i.e., the welded portion of the thermoplastic components <NUM> travels aft of the welding position after being welded. One or more of the force applicators <NUM> may be disposed at a "leading" position (e.g., see <FIG>). These force applicators <NUM> may be referred to as "leading force applicators <NUM>". The term "leading" as used herein refers to a position in front of where welding occurs; i.e., the thermoplastic components <NUM> to be joined will encounter a leading force applicator <NUM> prior to being welded, prior to the weld position. Thermoplastic components <NUM> may be welded along a straight linear line or may be welded along a line that is other than a straight linear line, or any combination thereof.

Force applicator <NUM> embodiments may include at least one roller <NUM> having a rotational axis <NUM> that is perpendicular to the weld direction. The roller <NUM> is in direct or indirect contact with the thermoplastic component workpieces <NUM> and rotates as the workpieces <NUM> move relative to the welding subsystem <NUM>. In some embodiments, a force applicator <NUM> may have a single roller <NUM> (e.g., see <FIG>). In some embodiments, a plurality of independent force applicators <NUM> each having a single roller <NUM> (e.g., see <FIG>) may be used. In some embodiments, a force applicator <NUM> may have a plurality of rollers <NUM> acting in concert (e.g., see <FIG>). In those embodiments where a force applicator <NUM> has a plurality of rollers <NUM> acting in concert, the plurality of rollers <NUM> may be mounted to a carriage structure <NUM> allowing the plurality of rollers <NUM> to collectively act as a single structure.

In some embodiments, a force applicator <NUM> may have a rotating belt assembly <NUM> with a belt <NUM> that rotates around a plurality of support rollers <NUM> (e.g., see <FIG>). The belt <NUM> and the support rollers <NUM> have a rotational axis <NUM> that is perpendicular to the weld direction. The belt <NUM> may be configured to contact a thermoplastic component workpiece over an engagement distance <NUM>. The belt <NUM> has an exterior surface <NUM> and an interior surface <NUM>. The rotatable belt <NUM> extends between and wraps around a forward support roller 142F and an aft support roller 142A separated from one another. Some belt assembly <NUM> embodiments may include one or more additional support rollers ("intermediary support rollers 142I") disposed between the forward and aft support rollers 142F, 142A. The support rollers 142F, 142A, 142I may be in contact with the interior surface <NUM> of the rotatable belt <NUM>. The exterior surface <NUM> of the rotatable belt <NUM> may be applied directly to the surfaces of the thermoplastic component workpieces <NUM>. Examples of a belt assembly <NUM> having forward and aft support rollers 142F, 142A and one or more intermediary support rollers 142I is shown in <FIG>. In the embodiment shown in <FIG>, a plurality of intermediary support rollers 142I are attached to a carriage for mounting the intermediary support rollers 142I in concert. The intermediary support rollers 142I help to increase the uniformity of the force applied against the thermoplastic component workpieces <NUM> along the length of the belt assembly <NUM>.

The force applicator <NUM> embodiments shown in <FIG> represent non-limiting examples of force applicator <NUM> configurations. In some component positioning subsystems <NUM>, combinations of different force applicator <NUM> configurations may be used.

In some embodiments, a force applicator <NUM> may include a biasing structure <NUM> (e.g., one or more springs, pneumatic cylinders, hydraulic cylinders, a weight, etc.) operable to force the roller(s) <NUM> or a belt assembly <NUM> in a direction toward (and in some embodiments against) a thermoplastic component workpiece <NUM>. The force applied by the biasing structure <NUM> may increase the uniformity of the force applied to the workpiece by the force applicator <NUM>. As shown in <FIG>, some belt assembly <NUM> embodiments may include a biasing structure <NUM> operable to bias intermediary support rollers 142I against the interior surface <NUM> of the belt <NUM>; e.g., to increase the uniformity of the force applied by the belt <NUM> against the thermoplastic component workpieces <NUM> along the engagement distance <NUM> of the belt <NUM> (see <FIG>).

Referring to <FIG>, in some embodiments a force applicator <NUM> may be mounted in a manner that permits a second axis of rotation. As described above, force applicator rollers <NUM> (or belts <NUM>) are configured to rotate about a first axis <NUM> that is perpendicular to the weld direction. In these embodiments, a force applicator <NUM> is mounted in a manner that permits a second axis <NUM> of rotation orthogonal to the first axis <NUM>. For example, if the weld direction extends along an X-axis and the first rotational axis <NUM> of the roller <NUM> extends along a Y-axis, then the second rotational axis <NUM> of the roller <NUM> may extend along a Z-axis, where X, Y, and Z are orthogonal axes. In this manner, the roller <NUM> (or belt <NUM>) is mounted to pivot about an axis (e.g., the Z-axis) to help maintain rotational axis alignment of the roller <NUM> (or belt <NUM>) perpendicular to the weld direction; e.g., as may be beneficial for weld lines <NUM> that are not straight.

In present disclosure system <NUM> embodiments that utilize inductive heating, components of the force applicators <NUM> may be made of electrically non-conductive material to avoid any collateral inductive heating that may occur in the proximity of an induction welding probe <NUM>.

Referring to <FIG>, some embodiments of the component positioning subsystem <NUM> include a first lateral side trailing force applicator 140A and a second lateral side trailing force applicator 140B. Both the first and second lateral side trailing force applicators 140A, 140B may be disposed on the same side of the thermoplastic component workpieces <NUM> to be welded (e.g., on the top) and they are laterally separated from one another a distance so as to be on opposite lateral sides of the weld zone <NUM>; i.e., the first lateral side trailing force applicator 140A is disposed on a first lateral side of the weld zone <NUM> and the second lateral side trailing force applicator 140B is disposed on a second lateral side of the weld zone <NUM>, opposite the first lateral side. Hence, the weld zone <NUM> is exposed between the first and second lateral side trailing force applicators 140A, 140B. As indicated above, embodiments of the present disclosure may include one or more sensors <NUM> operable to sense the weld zone <NUM> to monitor the welding process. The lateral separation between the first and second lateral side trailing force applicators 140A, 140B facilitates sensing of the weld zone <NUM>; e.g., permits line-of-sight sensing.

As indicated above, a force applicator <NUM> (in this case the first and second trailing force applicators 140A, 140B) may be configured in a variety of different configurations. <FIG> illustrate an embodiment wherein the first and second trailing force applicators 140a, 140B each include a single roller <NUM>. <FIG> illustrate an embodiment that includes a plurality of independent first lateral side trailing force applicators 140A each having a single roller <NUM>, and a plurality of independent second lateral side trailing force applicators 140B each having a single roller <NUM>. <FIG> illustrate an embodiment that includes a first lateral side trailing force applicator 140A having a plurality of rollers <NUM> acting in concert, and a second lateral side trailing force applicator 140B having a plurality of rollers <NUM> acting in concert. <FIG> illustrate an embodiment that includes a first lateral side trailing force applicator 140A having a belt assembly <NUM>, and a second lateral side trailing force applicator 140B having a belt assembly <NUM>. As indicated herein, the above described trailing force applicator configurations 140A, 140B are non-limiting examples. In the examples shown in <FIG>, the first and second lateral side trailing force applicators 140A, 140B are shown with the same configuration on both lateral sides; e.g., both the first and second lateral side trailing force applicators 140A, 140B have single rollers <NUM>, or both have a belt assembly <NUM>, etc. The present disclosure is not limited to having first and second lateral side trailing force applicators 140A, 140B that mirror one another. For example, embodiments of the component positioning subsystem <NUM> may include a first lateral side trailing force applicator 140A configured as a belt assembly <NUM> and include a plurality of second lateral side trailing force applicators 140B; e.g., a plurality of single roller <NUM> force applicators <NUM>. In addition, more than one type of force applicator <NUM> (e.g., a single roller <NUM>, or rollers <NUM> acting in concert, or a belt assembly <NUM>, etc.) may be disposed on a lateral side, and the types of the force applicators <NUM> (e.g., a single roller <NUM>, or rollers <NUM> acting in concert, or a belt assembly <NUM>, etc.) disposed on one lateral side may be different from the types of force applicators <NUM> disposed on the opposite lateral side.

As indicated above, in some embodiments both the first and second lateral side trailing force applicators 140A, 140B may be disposed aft of the position where welding occurs. The embodiments shown in <FIG>, <FIG>, <FIG>, and <FIG> illustrate the first and second lateral side trailing force applicators 140A, 140B disposed aft of the induction welding probe <NUM>. Hence, during the welding process the first and second lateral side trailing force applicators 140A, 140B "trail" the weld zone <NUM>; i.e., the newly welded region of the workpieces <NUM> reaches the first and second lateral side trailing force applicators 140A, 140B subsequent to being welded. In some embodiments a portion of the trailing force applicators 140A, 140B may be disposed adjacent the welding position and a portion of the trailing force applicators 140A, 140B may be disposed aft of the position where welding occurs. The embodiment shown in <FIG> illustrates an embodiment wherein each of the first and second lateral side trailing force applicators 140A, 140B includes a plurality of independent single roller <NUM> force applicators <NUM> and the induction welding probe <NUM> is disposed between (and therefore adjacent) a forward pair of the independent single roller <NUM> force applicators <NUM>, and the remaining independent single roller <NUM> force applicators <NUM> are disposed aft of the position where welding occurs. In similar fashion, <FIG> illustrates the induction welding probe <NUM> disposed between (and therefore adjacent) a forward portion of the belt assemblies <NUM> of the first and second lateral side trailing force applicators 140A, 140B and aft portions of the belt assemblies <NUM> of the first and second lateral side trailing force applicators 140A, 140B trail behind the weld zone <NUM>.

Embodiments of the component positioning subsystem <NUM> may include one or more leading force applicators <NUM> disposed forward (or "leading") the weld zone <NUM>. The force applicator <NUM> configurations described above are applicable to both the leading and trailing force applicators <NUM>, and the leading force applicators <NUM> may be the same as or different from the trailing force applicators. <FIG> illustrate embodiments of the component positioning subsystem <NUM> that include a first lateral side leading force applicator 240A and a second lateral side leading force applicator 240B both disposed forward (or "leading") the weld zone <NUM>. Both the first and second lateral side leading force applicators 240A, 240B may be disposed on the same side of the thermoplastic component workpieces <NUM> to be welded (e.g., on the top) and they are laterally separated from one another a distance so as to be on opposite lateral sides of the weld zone <NUM>; i.e., the first lateral side leading force applicator 240A is disposed on a first lateral side of the weld zone <NUM> and the second lateral side leading force applicator 240B is disposed on a second lateral side of the weld zone <NUM>, opposite the first lateral side. Hence, the weld zone <NUM> is exposed between the first and second lateral side leading force applicators 240A, 240B. In the embodiments shown in <FIG>, the leading force applicators 240A, 240B and the trailing force applicators 140A, 140B are disposed on the same side of the workpieces <NUM>; e.g., on the top. In some embodiments, leading force applicators 240A, 240B and trailing force applicators 140A, 140B may be disposed on opposite sides of the workpieces <NUM>; e.g., leading force applicators 140A, 140B disposed on the bottom side of the workpieces <NUM> and trailing force applicators 240A, 240B disposed on the top side of the workpieces <NUM>.

In some embodiments, force applicators <NUM> may be disposed both above and below the workpieces <NUM> in the trailing position or the leading position or both.

As indicated above, in the welding process thermoplastic component workpieces <NUM> to be joined are either moved in a weld direction and the welding subsystem <NUM> remains static, or the workpieces <NUM> to be joined are held static relative to the weld direction and the system is moved, or some combination thereof. In a present disclosure system embodiment wherein the component positioning subsystem <NUM> and the thermoplastic component welding subsystem <NUM> are moved in the weld direction, the present disclosure system <NUM> may include an actuation system (e.g., robotics) operable to move elements of the component positioning subsystem <NUM> and the thermoplastic component welding subsystem relative to the thermoplastic component workpieces <NUM>. For example, elements of the component positioning subsystem <NUM> and the thermoplastic component welding subsystem may be mounted on a robotic actuator controlled to apply the same to the workpieces <NUM>. The robotic actuator may be used to apply biasing force against one or more of the force applicators.

In some embodiments, the present disclosure may include a system controller <NUM> in communication with system components (e.g., the welding subsystem <NUM>, fluid powered force applicator biasing systems, actuation systems such as robotic actuators, weld zone sensors <NUM>, etc.) and the like to control and or receive signals therefrom to perform the functions described herein. The system controller <NUM> may include any type of computing device, computational circuit, processor(s), CPU, computer, or the like capable of executing a series of instructions that are stored in memory. The system controller <NUM> may be configured as hardware or software or any combination thereof. The instructions may include an operating system, and/or executable software modules such as program files, system data, buffers, drivers, utilities, and the like. The executable instructions may apply to any functionality described herein to enable the system <NUM> to accomplish the same algorithmically and/or coordination of system components. The system controller <NUM> may include a single memory device or a plurality of memory devices and the present disclosure is not limited to any particular type of memory device. The system controller <NUM> may include, or may be in communication with, an input device that enables an operator to enter data and/or instructions, and may include, or be in communication with, an output device configured, for example to display information (e.g., a visual display or a printer), or to transfer data, etc. Communications between the system controller <NUM> and other system components may be via a hardwire connection or via a wireless connection.

Referring to <FIG>, an example of how an embodiment of the present disclosure system <NUM> may be utilized is provided. <FIG> illustrates a side view of a pair of thermoplastic component workpieces <NUM> that are to be joined together. In this example, the workpieces <NUM> are moved relative to the elements of the component positioning subsystem <NUM> and the thermoplastic component welding subsystem <NUM> in the direction shown by arrow <NUM>. An induction welding probe <NUM> is shown disposed between leading force applicators 240A, 240B and a trailing force applicators 140A, 140B. A weld zone <NUM> is disposed at the junction of the thermoplastic workpieces <NUM>. As the workpieces <NUM> traverse through the system <NUM>, the weld zone <NUM> is created at the induction welding probe <NUM> and continues in the weld direction (forward to aft) for a distance until the thermoplastic materials solidify. Depending on various factors, the weld zone <NUM> may continue for a distance and be disposed at least partially between the lateral side trailing force actuators 140A, 140B. <FIG> illustrate a plurality of sensors <NUM> positioned to sense parameters within the weld zone <NUM> and beyond, some of which are positioned to sense along a line-of-sight. <FIG> illustrates an embodiment wherein the induction welding probe <NUM> is disposed between some (or a portion of) lateral side trailing force applicators 140A, 140B. In some applications, it may be beneficial to position the induction welding probe <NUM> in this manner. It should be noted that in this alternative induction welding probe <NUM> embodiment, using the present disclosure it is still possible to sense the weld zone <NUM> using line-of-sight sensors <NUM>. The present disclosure is, therefore, not limited to disposing the induction welding probe <NUM> forward of the trailing force applicators 140A, 140B.

The respective leading and trailing force applicators 240A, 240B, 140A, 140B facilitate positioning of the thermoplastic components <NUM> to be joined as the components traverse through the system <NUM>. In those system <NUM> embodiments that utilize trailing force applicators 140A, 140B configured as belt assemblies <NUM>, the engagement distance <NUM> of the belt assemblies <NUM> (see <FIG>) may be chosen to be long enough to ensure thermoplastic solidification prior to exiting the belt assemblies <NUM>.

The present disclosure system is described above as having, but not limited to a thermoplastic component welding subsystem <NUM> utilizing induction welding. In some embodiments, the thermoplastic component welding subsystem <NUM> may use an alternative welding process such as ultrasonic welding or the like. In addition, the present disclosure is described above in terms of welding a thermoplastic material that includes electrically conductive elements such as carbon fibers or the like. In some embodiments, thermoplastic components <NUM> that do not include electrically conductive elements may be inductively welded using an electrically conductive body (sometimes referred to as a "susceptor") placed in contact with the thermoplastic components <NUM> over the area to be welded. In these embodiments, the induction welding probe <NUM> may be used to heat the susceptor, and the susceptor in turn heats the regions of the thermoplastic components <NUM> to be welded to the appropriate temperature for joinder. Hence, in these embodiments the thermoplastic components <NUM> need not include electrically conductive elements.

While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the invention as defined by the claims.

The singular forms "a," "an," and "the" refer to one or more than one, unless the context clearly dictates otherwise. For example, the term "comprising a specimen" includes single or plural specimens and is considered equivalent to the phrase "comprising at least one specimen. " The term "or" refers to a single element of stated alternative elements or a combination of two or more elements unless the context clearly indicates otherwise. As used herein, "comprises" means "includes. " Thus, "comprising A or B," means "including A or B, or A and B," without excluding additional elements.

It is noted that various connections are set forth between elements in the present description and drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect.

Claim 1:
A system (<NUM>) for welding thermoplastic components (<NUM>) along a weld line (<NUM>), comprising:
a component positioning system (<NUM>) that includes a trailing force applicator (40T); and
a welding subsystem (<NUM>) configured to weld the thermoplastic components (<NUM>) together at a weld zone (<NUM>), the welding subsystem (<NUM>) having a probe (<NUM>),
characterised in that:
the trailing force applicator (40T) has a first lateral side trailing force applicator (140A) disposed on a first lateral side of the weld line (<NUM>) and a second lateral side trailing force applicator (140B) disposed on a second lateral side of the weld line (<NUM>);
the first lateral side trailing force applicator (140A) and the second lateral side trailing force applicator (140B) are laterally spaced apart from the weld zone (<NUM>);
at least a portion of the first lateral side trailing force applicator (140A) and at least a portion of the second lateral side trailing force applicator (140B) are disposed aft of the weld zone (<NUM>); and in that
the system (<NUM>) is configured so that the first lateral side trailing force applicator (140A), the second lateral side trailing force applicator (140B), and the welding subsystem probe (<NUM>) are moved relative to the thermoplastic components (<NUM>) during welding, or the thermoplastic components (<NUM>) are moved relative to the first lateral side trailing force applicator (140A), the second lateral side trailing force applicator (140B), and the welding subsystem probe (<NUM>).