Abstract:
The present invention provides a tool  1  for curing a composite component, the tool comprising a lay-up surface  8  for laying-up layers of an uncured composite component, a cover assembly  9  for moving in relation to the lay-up surface to cover a layed-up uncured composite component on the lay-up surface, the cover assembly comprising a sealable cover for sealing around the uncured composite component on the lay-up surface to form a sealed zone, and a vacuum port  25  for providing a vacuum to the sealed zone, wherein the tool further comprises at least one heating element  15, 53  within the sealed zone for heating the uncured composite component. The invention also provides a method of manufacturing a composite component and a composite component. The composite component may form at least part of a piece of aircraft furniture, such as an aircraft seat shell.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the benefit of United Kingdom Patent Application No. 1502323.7 filed Feb. 12, 2015, the contents of which are incorporated herein by reference in their entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention concerns a tool for curing a composite component, the tool comprising a lay-up surface for laying-up layers of an uncured composite component. The invention also concerns a method of manufacturing a composite component and a composite component. The composite component may form at least part of a piece of aircraft furniture, such as an aircraft seat shell. 
         [0003]    Seat shells for aircraft are often manufactured using composite laminate materials. The reason for using composite materials in the structure mostly is due to its lightweight and superior strength-to-weight properties of the material. These composite materials could be monolithic or sandwich composite laminates or a combination. The constituent materials for monolithic composite laminates are pre-impregnated materials (prepregs of resin impregnated fibres) whereas for sandwich composite laminates they are prepregs and a core material (e.g. honeycomb, foam). Honeycomb materials are preferable as a core material. Prepregs may be made with glass and/or carbon fibres impregnated with thermoset resin (e.g. phenolic or epoxy resin). The honeycombs core may be made with aramide based paper. Prepregs are often stored in freezers to ensure they are kept under the correct conditions. 
         [0004]    The composite materials are prepared in a clean room by laying up the prepregs (and cores) on a mould tool at room temperature. After being layed-up the composite materials are bagged up using a polytetrafluoroethylene (PTFE) release film (if required), a rubber intensifier layer (to enable a uniform pressure to be applied on the composite component), a breather layer (to absorb excess resin) and then nylon bagging materials. A vacuum is then applied through a port in the nylon bagging (known as de-bulking). The mould tool with these bagged up materials is transferred to an oven or autoclave where the materials are connected to a different vacuum port and taken through a heating cycle (typically, heating to 135° C. and remaining at that temperature for a certain period of time depending upon the prepregs, typically 1 hour for phenolic resin prepregs) to cure the material. The materials are allowed to cool down to room temperature before extracting the cured and moulded laminate off the tool. 
         [0005]    Following the curing of the material, the moulded part is machined into the required shape and profile as per the engineering design and then passed through an assembly line to attach metal and plastic bonding attachments, cushions and electrical components to complete the seat structure for the aircraft. 
         [0006]    This process has many disadvantages. For example:
       1) The process can be very long, and therefore expensive, due to operating and man power costs. For example,
           a. Laying-up of the part can take up to 1.5 days due to the difficulties in laying-up prepregs, particularly when it is required to drape them over complex curved profiles.   b. Moving layed-up composites in and out of the oven or autoclave can take 4 to 5 hours, due to the number of different components being cured in the oven or autoclave at once, and the need to attach each to its own vacuum supply in the oven or autoclave. Also, other components cannot be moved into or out of the oven or autoclave during the curing process, meaning there is a significant lead time in waiting for the oven or autoclave to be empty.   c. The curing process can take 3 hours as the oven or autoclave can take a while to heat up to the desired temperature.   d. CNC machining of the cured composite component can take up to half a day but the lead time in waiting for a machine may be half to 1.5 days.   e. CNC (and other) machining of the cured component can produce a lot of dust, which needs to be extracted using a dust extraction system.   f. It is time-consuming to apply the nylon bagging as it needs to be carefully sealed each time, using a sealant.   g. Transferring the component to and from the CNC machine takes time.   
           2) The nylon bagging is not reusable and so creates waste.   3) An oven or autoclave is expensive and takes up a lot of space.   4) Laying-up may require the use of separate heating ovens, guns or blankets.   5) Separate vacuum supplies are required for de-bulking and during curing in the autoclave.   6) The process consumes a lot of energy and the equipment requires a large amount of maintenance.       
 
         [0020]    The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved tool for curing a composite component. 
       SUMMARY OF THE INVENTION 
       [0021]    The present invention provides, according to a first aspect, a tool for curing a composite component, the tool comprising a lay-up surface for laying-up layers of an uncured composite component, a cover assembly for moving in relation to the lay-up surface to cover a layed-up uncured composite component on the lay-up surface, the cover assembly comprising a sealable cover for sealing around the uncured composite component on the lay-up surface to form a sealed zone, and a vacuum port for providing a vacuum to the sealed zone, wherein the tool further comprises at least one heating element within the sealed zone for heating the uncured composite component. 
         [0022]    Providing a tool with an “in-built” heating element allows the layers of uncured composite to be layed-up onto a warm lay-up surface, making lay-up quicker. There is also no need for separate and/or time-consuming heating equipment, such as a heating gun, oven or blanket. 
         [0023]    In addition, the tool can be used for the curing process. The tool heats up more quickly to the desired temperature than an oven or autoclave, as the heat is provided within the sealed zone. The volume to be heated is also a lot smaller than the volume of a typical oven or autoclave. 
         [0024]    The tool also takes up much less space and is cheaper than a typical autoclave. Typically, the tool may be portable and may be provided with holes for allowing it to be lifted by a fork-lift, or similar. 
         [0025]    In addition, providing a moveable cover assembly and sealable cover allows a seal to be established around the uncured component quickly and easily. It does not require a separate sealant. 
         [0026]    Further, there is no movement of the tool into and out of an oven or autoclave required. Also, the same vacuum source can be used for both de-bulking and curing. 
         [0027]    The layers of the uncured composite component are typically prepregs layers. The composite component may be a monolithic or a sandwich component. 
         [0028]    The lay-up surface may be formed of a composite material, such as a carbon fibre composite. 
         [0029]    Preferably, the cover assembly comprises a cover heating element for heating an upper side of the layed-up uncured composite component. 
         [0030]    More preferably, the cover heating element is attached to an underside of the sealable cover. 
         [0031]    Preferably, the cover assembly is provided with an insulating layer (above the cover heating element) to prevent heat from the cover heating element escaping out of the cover assembly. 
         [0032]    Preferably, the cover heating element comprises a heating blanket, for example formed of a wire mesh, or similar, embedded within a carrier material. 
         [0033]    Preferably, the lay-up surface comprises a surface heating element for heating a lower side of the layed-up uncured composite component. This surface heating element could also be used to warm the layers during laying-up by heating the surface above ambient temperature. For example, the surface could be heated to a temperature of 40 to 50° C. 
         [0034]    More preferably, the surface heating element is embedded beneath a top layer of the lay-up surface. 
         [0035]    Providing heating elements on the upper and lower sides of a composite component allows more even heating and a more uniform composite structure. 
         [0036]    The tool preferably further comprises a vacuum source, such as a vacuum pump, connected to the vacuum port. 
         [0037]    Preferably, the vacuum port is provided in the cover assembly. 
         [0038]    A vacuum port may, additionally or alternatively, be provided at the lay-up surface. 
         [0039]    Preferably, the sealable cover is a shaped cover that holds its shape. The sealable cover therefore has a volume associated with it for containing the uncured composite component. 
         [0040]    More preferably, the sealable cover is shaped such that it has a lower edge region that can seal around the lay-up surface and a roof region that holds its shape to extend above the lay-up surface. 
         [0041]    Preferably, the sealable cover is movably mounted (for example, with a hinge) in relation to the lay-up surface. 
         [0042]    Alternatively, or additionally the sealable cover is movably mounted to the tool. 
         [0043]    Preferably, the sealable cover is supported by a frame structure. The frame makes the sealable cover easier to move and provides a guide to move the sealable cover over the lay-up surface (to move it on to or off from the lay-up surface). 
         [0044]    The frame may comprise a hinge to enable the sealable cover to be pivoted over the lay-up surface. The frame structure may comprise a gas strut to aid lifting/pivoting up of the frame and/or to maintain the frame and sealable cover in a position away from the lay-up surface, for example during lay-up. The frame structure may be provided with at least one handle. This aids with control of moving the frame and the cover. 
         [0045]    Preferably, the sealable cover is made of flexible material such that it flexes when the vacuum is provided to the sealed zone. 
         [0046]    More preferably, the sealable cover is made of an elastomeric material. For example, the sealable cover may be made from a silicon based elastomeric material, such as one called Viton (™). 
         [0047]    Preferably, the tool further comprises a cooling apparatus for cooling the composite component. This allows the component to be cooled, and therefore removed earlier, from the tool. This reduces the tool time for the component and allows more components to be cured in a given time period. 
         [0048]    More preferably, the cooling apparatus is located in the frame structure. 
         [0049]    Even more preferably, the frame structure comprises a plurality of air outlets from which cooling air may be expelled. 
         [0050]    Preferably, the frame structure comprises an internal airflow channel through which cooling air passes. 
         [0051]    Preferably, the tool comprises a vortex tube for supplying cooling air. 
         [0052]    Preferably, the lay-up surface comprises a main surface portion, provided with a number of attachment points for attaching raised portions on the main surface portion. 
         [0053]    Preferably, the lay-up surface comprises a main surface portion and a number of raised portions on the main surface portion. 
         [0054]    The raised portions provide a required geometric profile to allow the layers to be layed-up and layers to abut against the raised portions so that the same required profile of the component is achieved. The required profile may be an edge with, for example, a castellated shape or may be an internal hole and/or recessed area within the component. A raised portion may comprise a dowel (for example, made of nylon) for providing a hole in the component, for example, for a rivet or other fastener. 
         [0055]    Preferably, the raised portions comprise through-holes for attaching the raised portions to corresponding attachment points on the main surface portion. The raised portions may be attached with fasteners, such as bolts. 
         [0056]    The tool may be provided with sensors to sense the temperature and/or pressure inside the sealed zone. 
         [0057]    The tool may also be provided with a data recorder to record the temperature and/or pressure inside the sealed zone. The data recorded may be able to be transferred to a portable data storage device for transferring to a computer or a similar tool. The second tool may then provide the same temperature and/or pressure profile during another curing process on another component. Having a set temperature and/or pressure profile associated with the curing of the components may aid in authentication or certification of the components. 
         [0058]    The tool may be provided with a control panel that controls the tool to provide a required temperature and/or pressure. The control panel may be a programmable interface device (such as a proportional-integral-derivative controller, for keeping the heating and cooling rates constant) to allow the tool to provide a require temperature and/or pressure profile during curing. 
         [0059]    According to a second aspect not of the invention there is also provided a tool for curing a composite component, the tool comprising a lay-up surface for laying-up layers of an uncured composite component, and a cover assembly for moving in relation to the lay-up surface to cover a layed-up uncured composite component on the lay-up surface, the cover assembly comprising a sealable cover for sealing around the uncured composite component on the lay-up surface to form a sealed zone, wherein the sealable cover comprises a shaped cover that holds its shape. 
         [0060]    The sealable cover therefore has a volume associated with it for containing the uncured composite component. 
         [0061]    Preferably, the sealable cover is shaped such that it has a lower edge region that can seal around the lay-up surface and a roof region that holds its shape to extend above the lay-up surface. 
         [0062]    Preferably, the sealable cover is supported by a frame structure. The frame makes the sealable cover easier to move and provides a guide to move the sealable cover over the lay-up surface (to move it on to or off from the lay-up surface). 
         [0063]    The frame may comprise a hinge to enable the sealable cover to be pivoted over the lay-up surface. The frame structure may comprise a gas strut to aid lifting/pivoting up of the frame and/or to maintain the frame and sealable cover in a position away from the lay-up surface, for example during lay-up. The frame structure may be provided with at least one handle. This aids with control of moving the frame and the cover. 
         [0064]    Preferably, the tool further comprises at least one vacuum port for proving a vacuum to the sealed zone and wherein the sealable cover is made of flexible material such that it flexes when the vacuum is provided to the sealed zone. 
         [0065]    More preferably, the sealable cover is made of an elastomeric material. For example, the sealable cover may be made from a silicon based elastomeric material, such as one called Viton (™). 
         [0066]    Preferably, the sealable cover and/or cover assembly are made of durable materials. This allows them to be re-used. 
         [0067]    According to a third aspect of the invention there is also provided a tool for curing a composite component, the tool comprising a lay-up surface for laying-up layers of an uncured composite component, wherein the lay-up surface has a main surface portion and wherein the main surface portion is provided with a number of raised portions on the main surface portion, and/or a number of attachment points for attaching raised portions on the main surface portion. 
         [0068]    The raised portions provide a required geometric profile to allow the layers to be layed-up and layers to abut against the raised portions so that the same required profile of the component is achieved. The required profile may be an edge with, for example, a castellated shape or may be an internal hole and/or recessed area within the component. A raised portion may comprise a dowel (for example, made of nylon) for providing a hole in the component, for example, for a rivet or other fastener. 
         [0069]    Preferably, the raised portions are removable from the main surface portion to aid laying-up of the composite component to and/or extraction of the composite component from the lay-up surface. 
         [0070]    Preferably, the raised portions comprise through-holes for attaching the raised portions to corresponding attachment points on the main surface portion. The raised portions may be attached with fasteners, such as bolts. 
         [0071]    Preferably, the raised portions comprise an attachment device that projects outwardly from the raised portion in a direction away from the main surface portion. The attachment device can be used to secure an insert in the composite component. 
         [0072]    More preferably, the attachment device is a split pin. This allows one or more layers of the uncured composite component to be cut in the split of the pin. 
         [0073]    Preferably, the attachment device comprises a pluck-out hole, into which a tool can be inserted in order to pluck-out the raised portion from the main surface portion. 
         [0074]    Preferably, a surface of the raised portion comprises a cutting guide groove. This facilitates the cutting of one or more layers of the uncured composite component, as a cutter may be placed in the groove and moved along the groove to cut the layers. 
         [0075]    Preferably, either the raised portion comprises a biased retaining stud that is biased to project outwards from the raised portion, such that it may be retained in a stud-receiving recess in the main surface portion, or the raised portion comprises a stud-receiving recess for receiving a biased retaining stud that is biased to project outwards from the main surface portion. This allows for the raised portion to be secured in the main surface portion but also allow it to be efficiently removed. 
         [0076]    More preferably, the stud-receiving recess or biased retaining stud of the main surface portion is located in a socket and the wall of the socket or the wall of the raised portion acts as a cam that exerts force on the stud as the raised portion attached to the main surface portion. 
         [0077]    According to a fourth aspect of the invention, there is also provided a tool for curing a composite component, the tool comprising a main body and a lay-up surface portion for laying-up layers of an uncured composite component, wherein the lay-up surface portion is removable from the main body of the tool. This allows the lay-up surface portion to be removed and replaced with a different lay-up surface portion. This allows the tool to be used to manufacture a number of different shaped components. 
         [0078]    Preferably, the removable lay-up surface portion comprises an electrical connector and the main body comprises a corresponding electrical connection point. This allows the lay-up surface portion to be provided with electricity, for example for powering a heating element. 
         [0079]    Preferably, the removable lay-up surface portion comprises a vacuum port connector and the main body comprises a corresponding vacuum port. This allows the lay-up surface portion to be provided with a vacuum supply. 
         [0080]    Preferably, the removable lay-up surface portion comprises alignment members and the main body comprises corresponding alignment members, to allow the removeable lay-up surface portion to be aligned with the main body. 
         [0081]    According to a fifth aspect of the invention there is also provided a method of manufacturing a composite component, the method including the steps of laying-up an uncured composite component on the lay-up surface of the tool of any preceding claim, curing the composite component, and extracting a cured component from the lay-up surface. 
         [0082]    The curing process may involve the steps of heating the uncured composite component and also providing a vacuum to the uncured composite component. 
         [0083]    According to a sixth aspect of the invention there is also provided a composite component manufactured by the method described above. 
         [0084]    Preferably, the composite component forms at least part of a piece of aircraft furniture, such as an aircraft seat shell. 
         [0085]    It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa. Also, features described in relation to one aspect of the apparatus of the present invention may be incorporated into other aspects of the apparatus of the present invention. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0086]    Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: 
           [0087]      FIG. 1  shows a perspective view of a heat mould tool, 
           [0088]      FIG. 2  shows a perspective view of a composite seat shroud manufactured using the heat mould tool of  FIG. 1 , 
           [0089]      FIG. 3  shows a cross-sectional view of part of a composite tooling surface structure of the heat mould tool of  FIG. 1 , 
           [0090]      FIG. 4  shows a cross-sectional view of the heat mould tool of  FIG. 1 , 
           [0091]      FIG. 5  shows a perspective view of the heat mould tool of  FIG. 1  with a cover open, 
           [0092]      FIG. 6  shows a cross-sectional view of a section of a vacuum bag and frame of the heat mould tool of  FIG. 1 , 
           [0093]      FIG. 7  shows an exploded perspective view of the heat mould tool of  FIG. 1  without the cover and with an intensifier layer, 
           [0094]      FIG. 8  shows a perspective view of the heat mould tool of  FIG. 1  without the cover and with removable nylon dowels and blocks located at cut-out locations on the composite tooling surface structure, 
           [0095]      FIG. 9  shows a graph of a typical cure temperature cycle, 
           [0096]      FIG. 10  shows a schematic view of a cooling arrangement of a second embodiment heat mould tool, 
           [0097]      FIG. 11  shows a perspective view of a heat mould tool according to a third embodiment. 
           [0098]      FIG. 12  shows a perspective view of the heat mould tool of  FIG. 11 , with the removable tooling surface removed, 
           [0099]      FIG. 13  shows a perspective view of a first tooling surface for use with the tool of  FIGS. 11 and 12 , 
           [0100]      FIG. 14  shows a perspective view of a second tooling surface for use with the tool of  FIGS. 11 and 12 , 
           [0101]      FIG. 15  shows a cross-sectional view of the heat mould tool of  FIG. 11  with plug and vacuum hose connected, 
           [0102]      FIG. 16  shows a cross-sectional view of a frusto-conical insert for use with a heat mould tool according to a fourth embodiment, 
           [0103]      FIG. 17  shows a schematic cross-sectional view of a composite structure and heat mould tool surface of the heat mould tool according to a fourth embodiment, 
           [0104]      FIG. 18  shows a perspective view of a cuboidal block insert for use with a heat mould tool according to a fifth embodiment, and 
           [0105]      FIG. 19  shows a perspective view of a second cuboidal block insert for use with a heat mould tool according to a fifth embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0106]      FIGS. 1 and 3 to 8  show a heat mould tool  1  according to a first embodiment of the invention. The tool  1  is provided for the manufacture of composite seat shrouds  3 , constructed from layers of pre-preg material, such as that shown in  FIG. 2 . The seat shroud  3  forms the main back bone of a seat shell structure for use on an aircraft. 
         [0107]    The tool  1  comprises a base  5  that supports a tooling surface structure  7 , providing a tooling surface  8 , shaped to match the desired surface profile of the composite seat shroud  3 , upon which the composite seat shroud  3  is layed-up and cured, and a cover  9  that, in use, envelops and creates a sealed environment around the tooling surface  8 . The tooling surface  8  is roughly 0.9 m×1.3 m. It extends typically 100 mm beyond the desired “edge of part” of the seat shroud  3 . The tool  1  has a plug (not shown) for plugging into a conventional power socket and providing power to the tool. 
         [0108]    The tooling surface structure  7 , a cross-sectional schematic of part of which is shown in  FIG. 3 , comprises an upper-most portion of eight plies (cured at 180° C.) of carbon fibre composite  11 , the upper surface of the uppermost carbon fibre ply  8  providing the tooling surface  8 . The upper surface  8  of the uppermost carbon fibre ply is therefore maintained with a surface finish of 0.4 μm or better to ensure that the cured composite seat shroud  3  has an adequate surface finish. Below the eight plies of carbon fibre composite  11 , the tooling surface structure  7  comprises a layer of tooling surface heating elements  15  (electrical heater wires) that are electrically insulated from the rest of the tooling surface structure  7  by being sandwiched between an upper layer of two glass fibre composite plies  17  and a lower layer of three glass fibre composite plies  19  (the glass fibre composite plies cured at 135° C.). At the edges of the tooling surface structure  7 , electrodes  28  are attached to the tooling surface heating elements  15  so that they may be connected to a power source  29  (taking power from the power socket) in the base  5  of the tool  1 . The lower layer of three glass fibre composite plies  19  is painted with a thermally insulating coating  21  in order to minimise heat transfer into the base  5  of the tool  1  during the curing process. 
         [0109]    The tooling surface structure  7  is provided with a number of removable side panels (or edge bars)  64  of the tooling surface  8  to produce a shaped edge of the cured component. The shaped edge is castellated. The tooling surface structure  7  is provided with a number of sunken portions  66  in the tooling surface  8 , into which correspondingly shaped nylon rectangular blocks  63  may be placed so as to protrude above the tooling surface  8 . The tooling surface structure  7  is provided with a number of rounded apertures  67  into which nylon dowels  65  may be placed. These provide rivet/fastener holes in the cured component. Thus, the tooling surface  8  is provided with inserts that cut-outs  62  in pre-preg layers can be abutted against during lay-up, thereby providing clean internal and external edges and holes in the cured seat shroud  3 . 
         [0110]    The tooling surface structure  7  is mounted on top of the base  5  of the tool  1  such that the uncured composite seat shroud  3  can be layed-up directly onto the tooling surface  8 . The base  5  comprises a hollow composite box that houses a dry-vane vacuum pump  23  and the power source  29 , as can be seen in the cross-section shown in  FIG. 4 . The vacuum pump  23  is in fluid communication with a vacuum port  25  on the tooling surface  8  via a vacuum line  27 . The power source  29  is connected to the electrodes  28  of the tooling surface heating elements  15 . In use, the vacuum pump  23  is operated to obtain the desired vacuum pressure at the tooling surface  8  and the heating elements  15  are operated to obtain the desired temperature at the tooling surface  8 . During the cure process, the tool  1  is thermally monitored by temperature sensors or thermocouples (not shown) and thermally controlled by a PID (programmable interface device)  30 , such as a proportional-integral-derivative controller (for keeping the heating and cooling rates constant), the display of which is located on a first side  31  of the base  5 . A pressure gauge  32  is situated on the first side  31  of the base  5  such that the vacuum pressure level at the tooling surface  8  can also be monitored (vacuum pressure sensors not shown). 
         [0111]    There is also an emergency stop switch, switches/buttons (such as warm, vacuum, run, stop), and a USB port on the side  31 . The USB port can be used to input settings to the PID  30 . The PID  30  is also able to store program settings, and can be controlled by a user. The USB port may also be used to export the temperature and/or pressure profile of a cure cycle so that the cycle can be reproduced on a different tool. 
         [0112]    Forklift apertures  33  (each 21 cm×10 cm) are located on the first side  31  and on a second opposite side  34  of the base  5 , such that the tool  1  (weighing 60 kg) may be transported by a forklift (or similar) by inserting the forks of the forklift into the forklift apertures  33  located on one of the sides of the base  5 , passing the forks through the interior of the base  5  and out of the forklift apertures  33  located on the other side of the base  5 . Each aperture edge is covered with a rubber material to help prevent damage to the apertures  33 . 
         [0113]    Two air vents  35  (each 20 cm×20 cm) are located on a front end  37  and on a back end  38  of the base  5  in order to encourage air flow through the interior of the base  5  and therefore cool the vacuum pump  23 , power source  29 , and PID  30  contained therein. 
         [0114]    Two hinges  40  (one of which is shown in  FIG. 5 ) are located on the upper most edge of the back end  38  of the base  5 , and connect the base  5  with the cover  9  of the tool  1 , such that the cover  9  is pivotally mounted on the base  5  and can be opened as shown in  FIG. 5 . Once opened, the cover  9  is held in the open position by two gas springs  41 ,  42 ; one at each side of the cover  9 . Each gas spring  41 ,  42  comprises a piston rod  39  and a cylinder  43 . The piston rod is connected to a side of the base  5  and the cylinder  43  is connected to the same side of the cover  9 . The gas springs  41 ,  42  also prevent the cover  9  from being pushed back further than the open position (at approximately 90° to the base  5 ). When the tool is being used to cure the composite seat shroud  3 , the cover  9  is locked in the closed position by two toggle clamps  44  that secure the front end of the cover  9  to the front end  37  of the base  5 . 
         [0115]    The cover  9  comprises a rectangular aluminium frame  45  that in the closed position sits on top of the base  5  such that the frame  45  surrounds the tooling surface  8 . A flexible vacuum bagging sheet  47  spans the interior of the frame and is connected within an inner edge  48  of the frame  45  such that the vacuum bagging sheet  47  of the cover  9 , when the cover  9  is in the closed position, envelops the tooling surface  8 . A neoprene (or similar) seal  49  runs around the underside of the frame  45  at the interface between the frame  45  and the base  5  ensuring that when the cover  9  is in the closed position the tooling surface  8  is situated within a sealed environment, the pressure of which may be controlled by the vacuum pump  23 . 
         [0116]    A cross-sectional schematic of the frame  45  and vacuum bagging sheet  47  is shown in  FIG. 6 . The vacuum bagging sheet  47  has a bottom layer  51  made of a synthetic rubber sold under the trademark Viton by DuPont and, in use under the pressure applied by the vacuum pump  23 , is in contact with the upper surface of the lay-up of the composite seat shroud  3  on the tooling surface  8 . Above the bottom layer  51 , sits a layer of vacuum bagging sheet heating elements  53  distributed along the length of the vacuum bagging sheet  47  in order to provide a heat source to the upper surface of composite seat shroud  3  during the cure process. The vacuum bagging sheet heating elements  53  are connected to the power source  29  and controlled by the PID  30 , both situated within the base  5  of the tool  1 . The vacuum bagging sheet heating elements  53  are sandwiched between two thermally conductive heating blankets  55  that aid with the distribution of heat. The uppermost layer of the vacuum bagging sheet  47  is a thermally insulating layer  57  that prevents heat escaping from the cover  9 . 
         [0117]    The edges of the layers that comprise the vacuum bagging sheet  47  are received within a channel  58  that runs around the interior edge  48  of the aluminium frame  45  and are clamped within the channel  58  under the action of clamping screws  59  situated at intervals around the perimeter of the frame  45 . Each screw  59  enters an upper side of the frame, substantially opposite the side comprising the neoprene seal  49 , and act directly on a clamping plate  60  situated within the channel  58  such that the edges of the vacuum bagging sheet  47  can be clamped between the clamping plate  60  and a lower interior face of the channel  58 . It is expected that the vacuum bagging sheet  47  will be capable of being used for at least 300 curing operations. It can be replaced at a suitable time. 
         [0118]    An intensifier layer  61 , shown in  FIG. 7 , may be used to enhance the uniformity of the pressure distribution across the upper surface of the composite seat shroud  3  during the cure process. The intensifier layer  61  comprises a silicon sheet that has been moulded to match the desired profile of the upper surface of the composite seat shroud  3  and, in use, sits on top of the composite seat shroud  3  during the curing process, beneath the vacuum bagging sheet  47 . 
         [0119]    As mentioned, the tool is used in the manufacture of composite components constructed from pre-preg material, such as the composite seat shroud  3  shown in  FIG. 2 . In use, the tooling surface  8  of the tool  1  (provided with the appropriate inserts) is prepared with a coating of a suitable release agent, such as that sold in the UK under the trademark Frekote 700-NC by Henkel Ltd., and then warmed to 45° C. in order to aid the drape of the uncured pre-preg layers of the composite seat shroud  3  and facilitate the lay-up process onto the tooling surface  8 . A number of cut-outs  62  are located in the layers of the composite seat shroud  3 , and as the layers are layed-up by hand on to the tooling surface  8 , the cut-outs are lined up around the side panels/edge bars  64  and with the blocks  63  and dowels  65 . 
         [0120]    Once the uncured composite seat shroud  3  has been layed-up on the tooling surface  8 , it is covered with a release film (not shown) and then the intensifier layer  61  is placed on top. A breather cloth (not shown) is then placed on top of the intensifier layer  61  in order to encourage a uniform air pressure distribution and absorb any resin that bleeds out of the edges of the shroud  3  during the cure process. The cover  9  is then moved to the closed position and locked via the clamps  44 . The appropriate vacuum pressure is applied via the pump  23 , typically a vacuum of 1 bar (or 29.5 inHg) is applied to de-bulk the lay-up. Furthermore, it is possible to de-bulk the uncured composite component during the lay-up process after laying each layer of the component. It is noted that the tool  1  has a maximum vacuum loss of 1 inHg per 5 minutes. 
         [0121]    The PID  30  is programmed with the appropriate times and temperatures of the ramp-up (heating to a desired temperature at a given rate), dwell (at desired temperature for a given time) and cooling (to room temperature at a given rate) stages of the cure process as provided by the pre-preg manufacturer and the cure run cycle is started. The PID controls the temperature by controlling the heat provided by the heating elements  15  and  53 . A typical cure temperature cycle with a cure temperature of 135° C. is shown in  FIG. 9 . It is noted that the heating elements  15  and  53  are capable of achieving a ramp-up rate of between 0.5 and 5° C./min, a dwell temperature of between 25 and 150° C. with a variation of ±5° C. between top and bottom surfaces of the shroud  3 . 
         [0122]    Once the cure cycle is complete and the composite seat shroud  3  has cooled sufficiently, the cover  9  is unlocked by clamps  44  and moved to the open position. The breather cloth, intensifier layer  61 , and release film are removed to expose the upper surface of the cured composite seat shroud  3 . The nylon blocks  63  and dowels  65  are then removed. The cured composite seat shroud  3  can then be removed from the tooling surface  8 . It can then be polished around its perimeter to achieve a clean “edge of part”. 
         [0123]    A second embodiment of the tool comprises an arrangement which expedites the post-cure cooling of the tool. The frame  145  of the cover of the second embodiment of the invention, shown in  FIG. 10 , comprises a plurality of air outlets  170  positioned along the interior edge  148  of the frame. The air outlets  170 , shown in  FIG. 10  with arrows indicating the cooling air flow direction, are positioned such that cooling air may be expelled from them onto the surface of the cured composite component. 
         [0124]    The cooling air is supplied by a vortex tube  172 , the vortex tube  172  being fed by a compressed air supply  173 . A regulator  175 , which can regulate the flow of cooling air, may be positioned between the compressed air supply  173  and the vortex tube  172 . A programmable logic control device (PLC)  177  may be connected to the regulator  175  such that the cooling air flow volume can be adjusted to suit the required cooling rate. 
         [0125]    A flexible conduit  174  passes the cooling air from the vortex tube  172  to a connection inlet  176  located on the exterior edge of the frame  145 . An air amplifier  178  may be connected in series with the flexible conduit  174  which allows for alteration of the flow rate of the cooling air. The cooling air flows from the connection inlet  176  to the air outlets  170  through an air flow channel (not shown) located inside the frame  145 . 
         [0126]      FIG. 11  shows a perspective view of a heat mould tool  301  according to a third embodiment. The tool  301  is substantially the same as the heat mould tool  1  according to the first embodiment of the invention. However, the heat mould tool  301  now comprises a removable tooling surface  308 . The heat mould tool  301  is shown in  FIG. 12  with the removable tooling surface  308  removed. This arrangement advantageously allows different tooling surfaces to be used with the tool  301 , for example a first removable tooling surface  308  shown in  FIG. 13  and a second removable tooling surface  312  shown in  FIG. 14 . 
         [0127]    The removable tooling surfaces  308 ,  312  comprises four alignment members  370  which project outwardly from the rear side of the removable tooling surface (the rear side being opposite to the side onto which the composite is layed-up). The removable tooling surfaces can therefore be mounted upon the heat mould tool  301  by inserting the alignment members  370  into corresponding openings  372  located on the main body of the heat mould tool  301  and lowering the removable tooling surface  308 ,  312  into contact with the main body of the tool  301 . Once the tooling surface is in place, the removable tooling surface  308 ,  312  is fastened to the main body of the tool  301  by tightening clamping screws  375  which are arranged to clamp the alignment members  370  within the openings  372 . 
         [0128]    An electrical plug  376  is located on the rear side of the removable tooling surfaces  308 ,  312 . The plug  376  is arranged to be connected to a corresponding electrical socket  377  on the main body of the heat mould tool  301  such that power may be supplied to the heating elements located within the removable tooling surfaces  308 ,  312 . Similarly, a vacuum hose  379  also extends from the rear side of the removable tooling surfaces  308 ,  312 . The vacuum hose  379  is arranged to be connected to the pump  323  located within the main body of the heat mould tool  301  such that vacuum pressure may be applied to the removable tooling surfaces  308 ,  312 . The plug  376  and vacuum hose  379  are shown as connected to the heat mould tool in  FIG. 15 . 
         [0129]    A fourth embodiment of the tool, not shown, is arranged such that various removable inserts are mountable upon the tooling surface. The inserts enable composite panels to be cured with pre-formed cut-outs or with inserts cured in situ.  FIG. 16  shows a cross-sectional view of a frusto-conical insert  401  that is arranged to be mounted within a frusto-conical socket  403  located upon the tooling  408  surface, shown in  FIG. 17 . When mounted upon the tooling surface, the tooling end of insert  405  (the tooling end corresponding to the end with the largest diameter) sits flush with the tooling surface  408 . The insert is secured in place by a spring  402  and double-ended stud  404 ,  406  arrangement contained within a chamber  413  located in the body of the insert  401 , as shown in  FIG. 16 . 
         [0130]    A first stud  404  and a second stud  406  are positioned diametrically opposite one another within the chamber  413  and are arranged such that the tips of the studs  404 ,  406  pass through holes in the walls of the chamber and project out of diametrically opposite sides of the insert  401 . The end of each stud  404 ,  406  (the end being the distal end located within the body of the insert) is flanged so as to be of a larger diameter than the hole through which the stud tip passes. A helical spring  402  is positioned between the studs  404 ,  406  such that a first end of the spring  402  reacts on the flanged end of the first stud  404  and the second end of the spring reacts on the flanged end of the second stud  406 . The spring  402  is therefore arranged to push both studs  404 ,  406  outwardly from within the body of the insert  401 . The studs are retained within the chamber  413  by their flanged ends abutting the inner wall of the chamber  413 . 
         [0131]    Two corresponding stud-shaped recesses  415  are located on diametrically opposite sides of the frusto-conical socket  403  located in the tooling surface  408  and are arranged such that when the insert  401  is mounted within the socket  403 , the studs  404 ,  406 , sit within the recesses  415 . Therefore, as the insert is inserted into the socket, the walls of the socket  403  act as a cam which pushes the studs into the body of the insert  401 , against the force of the spring  402 . When fully inserted into the socket  403 , the spring  402  pushes the studs  404 ,  406  outwardly into the recesses  415 . This arrangement ensures that the insert  401  is securely mounted upon the tooling surface  408 . 
         [0132]    A split pin  407  projects outwardly from the tooling end  405  of the insert  401 . Such an arrangement allows for composite panels to be cured with inserts  411  in situ, thereby eliminating the post-cure steps of machining holes in a composite panel and mounting the inserts  411 . A first layer of pre-preg  409  is layed-up directly onto the tooling surface  408  such that the split pin  407  pierces the pre-preg  409 . A knife blade (not shown) may be passed within the split of the split pin  407  to cut the layed-up pre-preg  409  in the vicinity of the split pin  407 . An insert  411  may then be placed onto the split pin  407 , such that the split pin  407  is received within the insert. The remainder of the panel, for example a honey-comb core  417  and a pre-preg face sheet  418 , may then be layed-up around the insert  411 . 
         [0133]    Post cure, the insert  401  may be removed from the tooling surface by passing a suitable tool through a pluck-out hole  419  that passes in a radial direction through the split-pin  407  and pulling the insert  401  out of the tooling surface. This action causes the walls of the socket to again push the studs  404 ,  406  into the chamber  413  of the insert in a camming action. 
         [0134]    A cuboidal block insert  501  for use with a fifth embodiment heat mould tool is shown in  FIG. 18 . The block insert may be secured within a corresponding cuboidal socket on a tooling surface of the heat mould tool by a spring and stud  504  system located within the block insert  501  that acts substantially the same way as the spring  402  and stud system  404 ,  406  employed in the previously described frusto-conical insert  401 . Four cutting lines  503  run diagonally across the top face  505  of the block insert  501  (the top face  505  being the uppermost face of the block insert  501  when it is mounted within the cuboidal socket on the tooling surface) in a criss-cross pattern. The cutting lines  503 , which are grooves in the surface of the block insert  501 , facilitate the cutting of the cut-outs in the pre-preg during the laying-up process as a knife may be placed in the groove and moved in a straight line by following the cutting line  503  across the top face  505  of the block insert  501 . 
         [0135]    Similarly to the frusto-conical insert  401 , the block insert  501  comprises a pin  507  which projects out of the top face  505  of the block insert  501 . During the lay-up process the pre-preg is placed on to the block insert  501  and the pin  507  pierces the pre-preg. The pin  507  thereby positions the pre-preg and holds it in place during cutting. 
         [0136]    Post cure, the block insert  501  may be removed from the tooling surface by passing a suitable tool through a pluck-out hole  513  located in the top face and pulling the insert out of the tooling surface. 
         [0137]    A second cuboidal block insert  601  is shown in  FIG. 19 . The block insert is substantially the same as the block insert  501 . However, the cuboidal block insert  601  comprises two pins  607 ; one at each of the intersection points of the cutting lines  603  on the top surface of the block insert  601 . The block insert  601  also comprises two pluck-out holes  613  which facilitate removal of the insert from the tooling surface. 
         [0138]    Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described. 
         [0139]    A similar tool  1  may be used to produce any composite component, not just a seat shroud  3 . For example, the composite component may be significantly larger or significantly smaller than a seat shroud  3  or a different shape. 
         [0140]    The composite component may be a monolithic laminate (comprising just pre-preg layers) or a sandwich laminate (also comprising a comb structure) or a combination. 
         [0141]    The tooling surface  8 , intensifier layer  61  and cover  9  etc. may therefore be made to any suitable size/shape. 
         [0142]    The intensifier layer  61  may be made with carbon fibre combined with silicon. 
         [0143]    The tool  1  may be provided with any required number/shape/size of sunken portions and corresponding nylon dowels  65 , blocks  63  and side panels/edge bars  64 . For example, the side panels/edge bars  64  may provide a wavy or a zig-zag shape and the blocks  63  may be triangular or round. 
         [0144]    The forklift apertures may be provided on one side of the base  5  only. 
         [0145]    The cover  9  may be provided with a handle on one/each side to aid opening and closing of the cover  9 . 
         [0146]    The tool  1  may be provided with a network cable connection so that settings can be sent to the PID  30  using the internet. 
         [0147]    The tool  1  may be provided with rubber feet to minimize the impact when placing the tool  1  down and to ensure that the tool  1  does not shift positions. 
         [0148]    The tooling surface structure  7  may be formed of any suitable materials and/or any number of plies of composite material. 
         [0149]    The tool  1  may comprise a first tooling surface structure  7  which may be removed and replaced with a second tooling surface structure  7   a  such that two different composite components may be manufactured using the same tool  1 . 
         [0150]    The tool  1  may be provided with a number of separate tooling surfaces  8  such that a plurality of composite components may be manufactured during a single cure cycle. 
         [0151]    Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.