HEATING TOOL

A heating tool for preparing a planar material for cutting, the heating tool includes an airflow generator for generating an airflow; a heater for heating the generated airflow; a flow director assembly configured to direct the heated airflow, wherein the flow director assembly is configured to move between a first configuration and a second configuration, wherein in the first configuration, the flow director assembly directs the heated airflow towards a heating target position and, in the second configuration, the flow director assembly directs the heated airflow away from the heating target position; and means for powering motion of the flow director assembly between the first configuration and the second configuration.

TECHNICAL FIELD

The invention relates to heating tools for use in sealing a planar material, such as a composite material. The invention also relates to cutting systems and processes for planar materials.

BACKGROUND

It is common to prepare a large piece of a planar material and then cut the piece into individual units according to required shapes and quantities. For example, this may be applied to a composite material, such as a woven material or textile.

However, cutting a planar material can cause weaknesses such as frayed edges or loose threads. In order to reduce this effect, the material may be sealed along an intended cutting pattern, usually before the cutting is performed (although it may also be sealed after cutting). For example, the material may be sealed using a chemical treatment, such as an adhesive, or using a heat treatment, such as a targeted heating tool.

In many targeted heating tools, a heating element takes a significant amount of time and energy to heat up and cool down. Additionally, an operating temperature of the heating element can be hot enough to damage some components of the tool unless adequate heat dissipation is provided. The combination of a high operating temperature and a non-instantaneous starting and stopping can mean that a continuous flow of heat from the heating element (for example using an air flow past the heating element) is necessary in order to preserve a lifespan of the tool. As a result, the tool cannot be conveniently stopped and started according to the requirements of an arbitrary cutting pattern.

In view of the above, it is desirable to provide a heating tool suitable for applying heat in an arbitrary pattern on a planar material.

SUMMARY

According to a first aspect, this disclosure provides a heating tool for preparing a planar material for cutting, the heating tool comprising: an airflow generator for generating an airflow; a heater for heating the generated airflow; a flow director assembly configured to direct the heated airflow, wherein the flow director assembly is configured to move between a first configuration and a second configuration, wherein in the first configuration, the flow director assembly directs the heated airflow towards a heating target position and, in the second configuration, the flow director assembly directs the heated airflow away from the heating target position.

By providing such a flow director assembly, the heater can be operated continuously while activating and deactivating a heating effect at the heating target position. The second configuration could be referred to as a “standby” configuration, where the heating tool is ready to apply heat to the heating target position, without needing to restart the heater.

Even in cases where it is not necessary to continuously operate the heater, the flow director assembly may be advantageous for providing a sharp activation and deactivation of heating at the heating target position, without applying intermediate temperatures as the tool turns on or off. For example, after the heater is turned off, it may take a while before the flow of heated air completely stops. This may improve safety, as well as improving consistency of the heating effect.

In some embodiments, the flow director assembly comprises a receiving channel having an inlet, wherein the receiving channel is configured to move between a first receiving channel position for receiving the heated airflow at the inlet and a second receiving channel position away from the heated airflow.

With this configuration, the receiving channel can cool down while in the second receiving channel position, meaning that an average expected temperature of the receiving channel can be reduced, and a wider variety of materials are suitable.

The receiving channel may be connected to an exhaust channel for discarding the heated airflow. In this case, in the first configuration of the flow director assembly, the receiving channel is in the second receiving channel position, and in the second configuration of the flow director assembly, the receiving channel is in the first receiving channel position.

Discarding the heated airflow means that the heater can be operated continuously and a rise in internal temperature of the heating tool can be avoided while in the second configuration (when the heated airflow is not being used on the heating target position).

More specifically, the exhaust channel may comprise a mixing chamber for internally mixing the heated airflow with ambient air.

This may improve safety by reducing the temperature of the heated airflow before the airflow is discarded from the heating tool.

Additionally or alternatively, the receiving channel may be connected to a recycling channel for recycling the heated airflow through the heater. In this case, in the first configuration of the flow director assembly, the receiving channel is in the second receiving channel position and, in the second configuration of the flow director assembly, the receiving channel is in the first receiving channel position.

Recycling the heated airflow through the heater in the second configuration can improve energy efficiency. Recycling the heated airflow may in some cases be combined with reducing a power, current or voltage supplied to the heater in order to continue operating the heater while avoiding a rise in internal temperature of the heating tool.

Alternatively, the receiving channel may comprise an outlet directed towards the heating target position. In this case, in the first configuration of the flow director assembly, the receiving channel is in the first receiving channel position and, in the second configuration of the flow director assembly, the receiving channel is in the second receiving channel position.

In some embodiments, the flow director assembly comprises a directing channel having a nozzle that is configured to move between a first nozzle position for directing the heated airflow towards the heating target position and a second nozzle position for directing the heated airflow away from the heating target position. In this case, in the first configuration of the flow director assembly, the nozzle is in the first nozzle position and, in the second configuration of the flow director assembly, the nozzle is in the second nozzle position.

In some embodiments, the flow director assembly comprises a shutter configured to move between an open shutter position and a closed shutter position wherein, in the open shutter position, the heated airflow passes through the shutter and, in the closed shutter position, the heated airflow is deflected by the shutter. A shutter may be simpler to construct, operate and/or maintain when compared to a moveable channel or nozzle.

In some embodiments, the flow director assembly comprises an actuator for moving the heater between a first heater position and a second heater position, wherein a distance between the first heater position and the heating target position is smaller than a distance between the second heater position and the heating target position, and the first configuration comprises the first heater position and the second configuration comprises the second heater position.

By moving the heater, a distance between the heater and the heating target position can be reduced while heating, while still allowing adequate space for other components of the flow director assembly (such as a channel or shutter) while not heating the heating target position.

Preferably, the flow director assembly is biased to the second configuration. This means that, in the event of a failure such as a loss of power for controlling the configuration of the flow director assembly, the heating tool will fail safely into a configuration at which heat is not directed toward the heating target position.

According to a second aspect, the present disclosure provides a cutting system for a planar material, the system comprising: a heating tool according to the first aspect; a conveyor configured to move a piece of planar material and/or move the heating tool, such that the heating target position follows an intended cutting pattern on the piece of planar material; and a cutting tool configured to cut the piece of planar material along the intended cutting pattern.

In some embodiments, the cutting tool is the heating tool. For example, the heating tool may provide a heated airflow with sufficient temperature to simultaneously cut the planar material and seal an edge of the planar material.

According to a third aspect, the present disclosure provides a cutting method for a planar material, the method comprising: using a heating tool according to the first aspect, heating a piece of planar material along an intended cutting pattern; and using a cutting tool, cutting the piece of planar material along the intended cutting pattern.

In some embodiments, the cutting tool is the heating tool. For example, the heating tool may provide a heated airflow with sufficient temperature to simultaneously cut the planar material and seal an edge of the planar material.

DETAILED DESCRIPTION

FIGS.1A to1Care schematic perspective, plan and cross-section views respectively of a heating tool according to a first embodiment.FIG.1Cadditionally includes arrows illustrating air flow in the tool.

The heating tool comprises a heater1configured to receive an airflow, and heat the airflow as it passes through the heater. The airflow in this embodiment is generated by a compressed air supply (not shown) which feeds into inlet2of the heater1, as indicated by the arrow31inFIG.1C. Alternatively, the heater1may comprise an integrated airflow generator, such as an integrated fan or an integrated compressor, in which case the inlet2may be configured to receive uncompressed air (e.g. ambient air). The heater and airflow generator (e.g. compressed air supply) may be implemented using known components. The heating tool may, for example, provide a heated airflow at a temperature of at least 100° C., at least 200° C. or at least 400° C., and may provide the heated airflow at a temperature of less than 600° C. The compressed air supply may, for example, provide compressed air at between 2 and 8 bar and at a rate of between 200 and 600 I/min, preferably around 400 l/min.

The heated airflow is directed by a flow director assembly. When the heating tool is actively heating a target, the flow director assembly is in an active configuration (first configuration) in which the heated airflow is directed towards the heating target position (as illustrated by the arrow X). In one example, the heating tool may be oriented vertically above a target (i.e. the arrow X points downwards).

However, in the heating tool as shown inFIGS.1A to1C, the flow director assembly is in a standby configuration (second configuration) in which the flow director assembly directs the heated airflow away from the heating target position X. Preferably, in all embodiments, the flow director assembly is biased to the standby configuration (second configuration) so that, in the event of a loss of powered control, the flow director assembly reverts to the standby configuration under the power of one or more resilient elements (such as one or more spring mechanisms).

More specifically, the flow director assembly of this embodiment comprises a directing channel3with a fixed nozzle. The directing channel3is connected to the heater1to direct the airflow as it emerges from the heater1. This directing channel3is aligned to direct the airflow towards the heating target position X.

The flow director assembly further comprises a moveable receiving channel4. The receiving channel4is connected to a pneumatic rotating actuator5which is configured to rotate the receiving channel4between a first receiving channel position and a second receiving channel position.

As shown inFIG.1A, when the receiving channel4is in the first receiving channel position, its inlet is aligned with the nozzle of the directing channel3, and the airflow is redirected into an exhaust channel6for discarding the heated airflow, as shown using arrow32.

Referring now toFIGS.2A to2C, these are schematic views showing additional detail of the flow director assembly as it moves between the standby configuration and the active configuration.

In particular,FIG.2Ashows the receiving channel4in the first receiving channel position, as part of the standby configuration (second configuration), andFIG.2Bshows the receiving channel4in the second receiving channel position, as part of the active configuration (first configuration).

In the standby configuration (FIG.2A), the inlet of the receiving channel4blocks the heated airflow from travelling out of the directing channel3towards the heating target position X, and instead redirects the heated airflow into the exhaust channel6.

When the heating tool goes from the standby configuration to the active configuration, the pneumatic rotating actuator5moves the receiving channel4into a second receiving channel position (FIG.2B) where the receiving channel4is away from the heated airflow, and the heated airflow can reach the heating target position X. Specifically, the receiving channel4in this example is partially within the exhaust channel6in the second receiving channel position.

A transition from the standby configuration to the active configuration may further comprise moving the heater1. More specifically, as shown inFIGS.2A to2C, the heating tool may comprise a heater actuator10configured as a linear actuator for moving the heater1between a first heater position (FIG.2C) and a second heater position (FIGS.2A and2B). In this example, the directing channel3is attached to the heater1and moves with the heater1. This means that, in the active configuration (FIG.2C) the heater1and a nozzle of the directing channel3are closer to the heating target position, and are able to deliver heat more effectively. On the other hand, in the standby configuration, the heater1is retracted to the second heater position so that the directing channel3can fit behind and direct airflow into the receiving channel4.

It should be noted that whileFIGS.2A to2Cshow an example transition from the standby configuration to the active configuration, a transition from the active configuration to the standby configuration may be the reverse of that described above, and is illustrated by viewing the figures fromFIG.2CtoFIG.2A.

In the above description of the flow director assembly, the pneumatic rotating actuator5is merely an example, and the receiving channel4can be moved along any path between the first receiving channel position and the second receiving channel position, with the motion powered by any means such as pneumatic power or a motor.

Referring again toFIGS.1A to1C, these figures show an embodiment of the standby configuration (second configuration) in which the receiving channel4connects with an exhaust channel6. As shown in this example, this connection may simply be a connection between airflow in the receiving channel4and airflow in the exhaust channel6and does not require physical contact between the receiving channel4and the exhaust channel6.

Once the heated airflow has entered the exhaust channel6, the heated airflow is directed towards a mixing chamber8, as illustrated by the arrow33. As well as receiving air from the exhaust channel6, the mixing chamber8is configured to receive a cold air source7. The cold air source7may, for example, draw in room temperature air from outside the heating tool, and may draw air using a fan. The mixing chamber8allows the cold air source to mix with the heated airflow to produce cooled air. The cooled air is desirably cool enough to be safely released from the heating tool without posing a safety risk to any nearby operator. A maximum temperature of the cooled air may be controlled by controlling a rate of flow of the cold air source7, and may be controlled automatically using a temperature sensor in the mixing chamber8.

FIGS.1A and1Balso illustrate a mounting bracket9for supporting the heating tool, for example when including the heating tool on an assembly line. The heating tool may further comprise a cold skin surrounding the heating tool. The cold skin is thermally insulated from components which become hot during operation (such as the heater1and the channels3,4,6), so that an exterior of the heater tool is safe to touch during operation. The cold skin may be supported by one or more additional cooling elements such as fans arranged to drive air through or within the cold skin.

As one possible modification of the design inFIGS.1A to2C,FIGS.3A to3Care schematic perspective drawings illustrating part of an alternative flow director assembly. Although not fully shown, this alternative flow director assembly may again comprise a directing channel3and an exhaust channel6.

Referring toFIG.3A, the alternative flow director assembly comprises a shutter assembly including a shutter41and a window plate42having a hole43. When the shutter41is in an open shutter position, as shown inFIG.3A, the heated airflow can pass through the hole43. On the other hand, when the shutter41is in a closed shutter position, the shutter41blocks the hole43.

The shutter assembly may for example comprise an actuator44configured to move the shutter between the open and closed positions. The actuator44may be a pneumatic actuator, and may guide the shutter41parallel to a rail.

The shutter41may comprise a deflection element45for deflecting the heated airflow away from the hole43, and a cover41for covering the hole43. The deflection element45may be separated from the cover43by a thermal insulator46, so that the cover41is not directly heated by the heated airflow.

The shutter assembly may be arranged between the directing channel3and the heating target position, so that the deflection element45of the shutter can occupy a similar position to the receiving channel4inFIG.1A.

In other words, when the shutter is in the closed shutter position as shown inFIG.3B, the deflection element45, together with the window plate42, deflects the heated airflow into the exhaust channel6. At the same time, as previously shown inFIGS.2A and2B, the heater1and directing channel3are in a second heater position, retracted away from the heating target position.

On the other hand, when the shutter is in the open shutter position as shown inFIGS.3A and3C, the heated airflow passes through the window plate42at the hole43and is directed towards the heating target position. Additionally, as previously shown inFIG.3A, the heater1and directing channel3may be in a first heater position, extended toward the heating target position. As shown inFIG.3C, a nozzle of the directing channel3may extend through the hole43of the shutter assembly.

Various other ways of implementing the flow director assembly are also envisaged.

For example, as a modification of the exhaust channel6and mixing chamber8, the heated airflow could instead be recycled through the heater1through a secondary inlet in parallel with the inlet2. With this configuration, the heat energy of the heated airflow can be retained in the standby state. Of course, without any outlet for this heat energy, the temperature of heater1would rise. To address this, in embodiments the exhaust channel6is replaced with a recycling channel, the power dissipated in the heater1could be reduced in the standby state, for example by reducing the voltage or power supplied to the heater1. Nevertheless, the power supplied to the heater1can be matched to the power lost in order to maintain an operating temperature of the heater1.

As another alternative, the directing channel3may be modified so that its outlet is directed away from the heating target position. For example, the directing channel3may be directed towards an inlet of the exhaust channel6. In this case, the receiving channel4may comprise an outlet directed towards the heating position, and the receiving channel4may be moved to a position for receiving the heated airflow when the flow director assembly is in its active configuration and a position away from the heated airflow when the flow director assembly is in its standby configuration, contrary to the above examples.

As a further example, the directing channel3may have a nozzle section which can move relative to a main section. For example, the directing channel3may comprise a hinged section or a flexible section. The mobile nozzle may be configured to move between a first nozzle position for directing the heated airflow towards the heating target position and a second nozzle position for directing the heated airflow away from the heating target position. In other words, the mobile nozzle may be used as an addition or alternative to the receiving channel4.

Any of the heating tools described above can be used as part of a cutting system. For example,FIG.4is a schematic block diagram of a cutting system for cutting a planar material51.

Referring toFIG.4a piece of the planar material51is conveyed by a conveyor52along an assembly line. The planar material51may for example be a composite material. For example, the composite material may be a textile or a woven material. In one specific example, the composite material may be thermoplastic-reinforced fiberglass fabric.

The planar material51first passes under a heating tool53. The heating tool53is arranged so that its heating target position is a position on the conveyor52, such that when the planar material51passes it can be heated. As the conveyor52moves the planar material51relative to the heating tool53, the heating target position follows an intended cutting pattern on the piece of planar material51, and the cutting pattern is heat sealed in the planar material. The conveyor52may move the planar material51in two dimensions under the heating tool53.

Additionally, the heating tool53may have its own conveyor55(for example a conveyor perpendicular to conveyor52), and the two conveyors52and55may work together to provide two dimensional motion.

The planar material51then passes under a cutting tool54. The cutting tool54is similarly arranged to cut the planar material51as it passes. As the conveyor52moves the planar material51relative to the cutting tool54, the cutting tool54cuts the planar material51along the intended cutting pattern, and the edges of the cutting pattern experience reduced fray because they have been heat sealed by the heating tool53. The conveyor52may move the planar material51in two dimensions under the cutting tool54. Additionally, the cutting tool54may have its own conveyor56(for example a conveyor perpendicular to conveyor52), and the two conveyors52and56may work together to provide two dimensional motion.

The tools53,54and conveyors52,55and56may be controlled by controller57which coordinates motion of the conveyors and activation of the tools.

More preferably, rather than providing two separate tool heads which both have to follow a cutting pattern, the heating tool53and the cutting tool54are mounted on a single head which is moved along the intended cutting pattern, such that the heating tool53and cutting tool54can operate almost simultaneously.

Yet further, the heating tool53may be operated as a cutting tool54. More specifically, the heating tool53may be configured to melt the planar material51at the target heating position such that it breaks on either side of the cut, but at the same time the broken edges of the material51are sealed to reduce fraying.

FIG.5is a schematic flow chart of a cutting method according to an embodiment. This corresponds to, for example, the system illustrated inFIG.4. Step61comprises, using the heating tool53, heating the piece of planar material51along the intended cutting pattern. Step62comprises, using the cutting tool54, cutting the piece of planar material51along the intended cutting pattern.