The present invention relates to a fixture assembly for supporting a component to be machined. In particular, but not exclusively, the present invention relates to a fixture assembly for supporting a steel box-like container having regions which require precision machining.

It is known to safely dispose of a by-product of a manufacturing process or chemical reaction by placing it in a suitable container and storing the container at a waste storage site, typically deep underground. A conventional waste storage container is substantially box-like having a base and four side walls defining an upper edge region for a correspondingly sized and shaped lid to engage with and be securely attached to after the waste has been located in the container. The waste storage container (known as a‘skip’) is typically located in a larger box-like container (known as a‘box’) to add a second layer of security, protection and strength to the overall container assembly. The outer box also has an upper edge region for a

correspondingly sized and shaped lid to engage with and be securely attached to after the inner skip has been located in the outer box.

In view of the importance to achieve an efficient seal and attachment interface between the upper edge region of each container and their respective lid, the engaging surfaces of each component must be precisely machined by milling, drilling, and the like.

However, the walls and base of each component are prone to harmonic vibration when the component is excited during the machining process. This undesirably causes the component to act like a drum resulting in a poor surface finish on the engagement surfaces, poor tolerance parameters, reduced tool life, increased energy consumption and material/component waste, and extended machining times.

It is an aim of certain embodiments of the present invention to provide a fixture assembly for supporting a component of a waste storage container to

reduce/eliminate any movement and/or vibration of the component during a precision machining process. It is an aim of certain embodiments of the present invention to provide a fixture assembly for clamping a sheet portion of a component to be machined and dampening vibrations of the component during the machining process.

It is an aim of certain embodiments of the present invention to provide a fixture assembly for clamping a sheet portion of a component to be machined and measuring vibrations of the sheet portion during the machining process and controlling at least one parameter of the machining process based on the sensed vibrations.

According to a first aspect of the present invention there is provided a fixture for supporting a component to be machined, the fixture comprising:

at least one first airbag assembly engageable in an inflated state on a first surface of a sheet portion of a component to be machined; and

at least one second airbag assembly engageable in an inflated state on a second surface of the sheet portion such that in use the sheet portion is clamped between the first and second airbag assemblies.

Optionally, the fixture comprises a plurality of stop surfaces each configured to engage a respective outer surface of the component to locate the same in a desired position for machining.

Optionally, the fixture comprises a plurality of clamp members each configured to apply a clamp force to a respective outer surface of the component to urge the component towards a respective one of the stop surfaces.

Optionally, the plurality of clamp members comprises at least one X-axis clamp for urging the component towards at least one X-axis stop surface, at least one Y-axis clamp for urging the component towards at least one Y-axis stop surface, and at least one Z-axis clamp for urging the component towards at least one Z-axis stop surface. Optionally, the at least one X-axis clamp and the at least one Y-axis clamp each comprise selectively translatable clamp elements configured to engage an outer surface of the component.

Optionally, the at least one Z-axis clamp comprises a selectively rotatable clamp element configured to engage an edge region of the component when in a deployed position.

Optionally, the at least one Z-axis clamp comprises a selectively translatable clamp element configured to engage an outer surface of the edge region of the component.

Optionally, the fixture comprises a plurality of corner clamp members each

configured to apply a corner clamp force to a respective corner region of the component defined by a first sheet portion of the component oriented at an angle with respect to a second sheet portion of the component.

Optionally, each corner clamp member comprises a selectively translatable corner clamp element configured to engage an outer surface of the first sheet portion and an outer surface of the second sheet portion to apply the corner clamp force to the corner region.

Optionally, the at least one first airbag assembly comprises a plurality of outer airbag assemblies each configured to engage the first surface of a respective one of a plurality of connected sheet portions of the component, and wherein the at least one second airbag assembly comprises an inner airbag assembly configured to engage the second surfaces of each of the plurality of connected sheet portions of the component.

Optionally, the plurality of outer airbag assemblies comprises five outer airbag assemblies each configured to engage in an inflated state a respective one of five outer surfaces of an open box-like component, and the inner airbag assembly is configured to engage in an inflated state the five inner surfaces of the box-like component. Optionally, the inner airbag assembly comprises a plurality of inner airbags each configured to engage in an inflated state a respective inner surface of the

component.

Optionally, each airbag assembly comprises a back plate for mounting the airbag assembly to the fixture, a selectively inflatable airbag mounted to the back plate, and a protective layer located on an opposed side of the airbag to the back plate for engaging the component.

Optionally, the at least one first airbag assembly comprises a through aperture for locating a sensor array engageable with the sheet portion of the component.

Optionally, the sensor array comprises a vibration sensor for sensing a vibration in the sheet portion of the component during a machining process.

Optionally, the vibration sensor is coupled to a controller configured to selectively adjust a machining parameter and/or a clamp force and/or an inflation pressure of the airbag responsive to the sensed vibration.

Optionally, the machining parameter is a machining speed of a machine tool, such as a rotational speed of a drill bit, a reamer, or a milling tool.

Optionally, the machining parameter is a feed rate of a machine tool.

Optionally, the fixture comprises a main body assembly having a base portion, opposed side portions and a rear portion, and a top assembly removably mounted to the top assembly to form an upper portion of the fixture.

Optionally, the base portion comprises at least one mounting element for removably mounting the main body assembly to a pallet for a precision machining apparatus. According to a second aspect of the present invention there is provided a fixture system comprising at least one fixture according to the first aspect of the present invention.

Optionally, the fixture system comprises a first fixture for supporting a first box-like component, a second fixture for supporting a second box-like component, and a third fixture for supporting a lid component for locating on a respective one of the first and second box-like components.

According to a third aspect of the present invention there is provided a method of supporting a component to be machined, comprising:

inflating at least one first airbag assembly to engage on a first surface of a sheet portion of a component to be machined; and

inflating at least one second airbag assembly to engage on a second surface of the sheet portion such that in use the sheet portion is clamped between the first and second airbag assemblies.

Optionally, the method comprises:

engaging a respective outer surface of the component on one of a plurality of stop surfaces to locate the component in a desired position for machining.

Optionally, the method comprises:

by a plurality of clamp members, applying a clamp force to a respective outer surface of the component to urge the same towards a respective one of the stop surfaces, wherein the stop surfaces comprise at least one X-axis stop surface, at least one Y-axis stop surface, and at least one Z-axis stop surface.

Optionally, the method comprises:

by a plurality of corner clamp members, applying a corner clamp force to a respective corner region of the component defined by a first sheet portion of the component oriented at an angle with respect to a second sheet portion of the component. Optionally, inflating at least one first airbag assembly comprises:

inflating five outer airbag assemblies each to engage a respective one of five outer surfaces of an open box-like component; and

inflating at least one second airbag assembly comprises inflating an inner airbag assembly to engage the five inner surfaces of the box-like component to thereby clamp each sheet portion of the component between the inner airbag assembly and a respective one of the outer airbag assemblies.

Optionally, inflating the at least one second airbag assembly comprises selectively inflating five inner airbags to respectively engage each of the five inner surfaces of the open box-like component.

Optionally, the method comprises:

sensing a vibration in the sheet portion of the component during a machining process; and

selectively adjusting a machining parameter and/or a clamp force and/or an airbag inflation pressure responsive to the sensed vibration.

Optionally, the machining parameter is a machining speed of a machine tool, such as a rotational speed of a drill bit, a reamer, or a milling tool.

Optionally, the machining parameter is a feed rate of a machine tool.

Description of the Drawings

Certain embodiments of the present invention will now be described with reference to the accompanying drawings in which:

Figure 1 a illustrates a skip container according to certain embodiments of the present invention;

Figures 1 b and 1 c illustrate a skip lid for the skip container of Figure 1 a; Figure 2a illustrates a box container according to certain embodiments of the present invention for container the skip container of Figure 1 a;

Figures 2b and 2c illustrate a box lid for the box container of Figure 2a;

Figure 3 illustrates a palletised set of machining fixtures according to certain embodiments of the present invention;

Figure 4a illustrates an isometric front view of a skip fixture according to certain embodiments of the present invention with a skip located therein;

Figure 4b illustrates a first isometric front view of the main body assembly of the skip fixture of Figure 4a without a skip located therein and with the top assembly removed;

Figure 4c illustrates a further isometric front view of the main body assembly of Figure 4b;

Figure 4d illustrates an isometric rear view of the main body assembly of Figure 4b;

Figure 4e illustrates an isometric top view of the top assembly of the skip fixture of Figure 4a;

Figure 4f illustrates an isometric bottom view of the top assembly of Figure 4e;

Figure 4g illustrates an angle clamp of the skip fixture of Figure 4a;

Figures 4h and 4i illustrate a clamp assembly of the skip fixture of Figure 4a for engaging a lip region of a skip located in the fixture;

Figure 5a illustrates an airbag assembly of the skip fixture of Figure 4a for supporting the outer side faces of a skip located in the fixture; Figure 5b illustrates an airbag assembly of the skip fixture of Figure 4a for supporting the outer base face of a skip located in the fixture;

Figure 5c illustrates an airbag assembly of the skip fixture of Figure 4a for supporting the inner side faces and base of a skip located in the fixture;

Figure 5d illustrates a sensor array of the skip fixture of Figure 4a;

Figure 6a illustrates an isometric front view of a box fixture according to certain embodiments of the present invention with a box located therein;

Figure 6b illustrates a first isometric front view of the main body assembly of the box fixture of Figure 6a without a box present and with the top assembly removed;

Figure 6c illustrates a further isometric front view of the main body assembly of Figure 6b;

Figure 6d illustrates an isometric rear view of the main body assembly of Figure 6b;

Figure 6e illustrates an isometric top view of the top assembly of the box fixture of Figure 6a;

Figure 6f illustrates an isometric bottom view of the top assembly of Figure 6e;

Figure 7a illustrates an airbag assembly of the box fixture of Figure 7a for supporting the outer side faces of a box located in the fixture;

Figure 7b illustrates an airbag assembly of the box fixture of Figure 7a for supporting the outer base face of a box located in the fixture;

Figure 7c illustrates an airbag assembly of the box fixture of Figure 7a for supporting the inner side faces and base of a box located in the fixture; Figure 8a illustrates a lid fixture according to certain embodiments of the present invention supporting skip and box lids;

Figure 8b illustrates a main support body of the lid fixture of Figure 8a;

Figure 8c illustrates a first skip vacuum plate for locating on the main support body of Figure 8b;

Figure 8d illustrates a skip lid securely mounted to the first skip vacuum plate of Figure 8c;

Figure 8e illustrates a second skip vacuum plate for locating on the main support body of Figure 8b;

Figure 8f illustrates the skip lid securely mounted to the second skip vacuum plate of Figure 8e;

Figure 8g illustrates a first box vacuum plate for locating on the main support body of Figure 8b;

Figure 8h illustrates a box lid securely mounted to the first box vacuum plate of Figure 8g;

Figure 8i illustrates a second box vacuum plate for locating on the main support body of Figure 8b;

Figure 8j illustrates a box lid securely mounted to the second box vacuum plate of Figure 8i;

Figure 9 illustrates a lifting device for lifting the top assembly of Figure 6e;

Figure 10 illustrates a lifting device for lifting a skip and a box into the respective fixture; Figure 1 1 illustrates a lifting device for lifting the inner airbag assembly into the skip or box;

Figure 12 illustrates a method of machining a skip supported in the skip fixture according to certain embodiments of the present invention;

Figures 13a to 13c illustrate a method of machining a box supported in the box fixture according to certain embodiments of the present invention;

Figure 14 illustrates a lifting device for lifting the vacuum plates onto and from the lid fixture main body of Figure 8b;

Figures 15a and 15b illustrate a lifting device for lifting a skip lid or a box lid onto and from a respective vacuum plate;

Figures 16a and 16b illustrate a method of machining both sides and profile of a skip lid supported on the lid fixture of Figure 8a;

Figures 17a and 17b illustrate a method of machining both sides and profile of a box lid supported on the lid fixture of Figure 8a;

Figure 18 illustrates a method of operating a precision machining apparatus according to certain embodiments of the present invention;

Figure 19 illustrates an alternative embodiment of the lip clamp assemblies used on either the skip or box fixtures;

Figure 20 illustrates an alternative embodiment of the rear outer airbag assembly used on the box fixture;

Figure 21 a illustrates the support frame of an alternative embodiment of the inner airbag assembly used on the box fixture;

Figure 21 b illustrates the assembled inner air bag assembly of Figure 21 a; and Figure 22 illustrates an airline connector for coupling an air source to each airbag of the inner airbag assembly of Figures 21 a and 21 b.

Detailed Description

As illustrated in Figure 1 a, a skip 100 for containing waste, such as a by-product from a chemical reaction, has a base 102 and four side walls 104 extending therefrom which define a lip region 106 in the form of an outwardly extending flange. The flange provides a continuous and planar seal surface 108 for engagement with a respective seal surface 1 10 of a correspondingly shaped lid 1 12 illustrated in Figures 1 b and 1 c. The skip 100 and skip lid 112 are both made of stainless steel. The base of the skip is around 1.1 m x 1.1 m and around 8mm thick, and each of the four side walls is around 1.1 m x 0.9m and around 6mm thick. The seal surfaces 108,110 of the skip 100 and skip lid 1 12 must be precisely machined to ensure efficient engagement and sealing therebetween. The inner face 1 14 and other surfaces of the lip region 106 of the skip 100 must also be machined, along with surfaces of a pair of spaced apart lifting elements 1 16 extending from each side wall 104 proximal the lip region. The lifting elements 1 16 are for attaching a lifting device, such as a hoist, to manoeuvre the skip in use.

The flanged lip region 106 may also require drilling to provide a plurality of spaced apart holes (not shown) therein which align with corresponding holes in the lid 1 12 for securing the lid to the skip with bolts. The skip lid 1 12 is around 1.25m x 1 25m and around 20mm thick. The edge region of the skip lid 1 12 requires machining to provide the planar seal surface 1 10 and also the fixing holes 118. A circular bracket 150 is provided on the outer surface of the skip lid 112 to allow a lifting device to attach to the skip lid for manoeuvring the same during machining and/or onto or off the skip 100. A centre hole 120 is provided for mounting a filter assembly to allow air/moisture to leave the interior of the skip when the lid is fitted in use.

As illustrated in Figure 2a, a box 200 for containing the skip 100 has a base 202 and four side walls 204 extending therefrom which define an upper edge region 206 in the form of an inwardly extending flange. The edge region 206 provides a continuous and planar seal surface 208 for engagement with a respective seal surface 210 of a correspondingly shaped lid 212 illustrated in Figures 2b and 2c.

Each corner of the box is strengthened by an internal corner member 220 extending from the base 202 to the upper edge region 206.

Each corner member 220 has a plurality of holes 222 therein. Each corner region of the edge region 206 is raised with respect to the planar seal surface 208 and an upper surface of each raised corner region includes an aperture 224 extending into the interior of the corner region. The aperture 224 allow adjacent boxes in a stack of boxes to be locked together by a suitable locking element. A drain pocket 226 is machined in each corner of the box below the raised corner region to allow water ingress to exit and prevent corrosion. An inner plate directs water or the like towards the drain pocket 226. The box 200 and lid 212 are both made of stainless steel. The base of the box is around 1.6m x 1 6m and around 8mm thick, and each of the four side walls is around 1.6m x 1.1 m and around 6mm thick. The seal surfaces 208,210 of the box 200 and the box lid 212 must be precisely machined to ensure efficient engagement and sealing therebetween. The inner face surface 214 of the inwardly extending flange 206 and the surfaces of the raised corner regions of the box 200 must also be machined. The raised corner regions each define a platform for a corresponding foot region on the base of another box to locate such that a plurality of the boxes can be stacked. Each foot also requires machining to ensure stable engagement with a raised corner region of a lower box in the stack. The inwardly extending flange 206 also requires drilling to provide a plurality of spaced apart holes 225 therein which align with corresponding holes 226 in the lid 212 for securing the lid to the box with bolts. A locating hole 228 is also provided in each of a pair of opposed corners of the seal surface 210 for locating the lid on the box prior to attachment thereto. The box lid 212 is around 1.6m x 1 6m and around 18mm thick. The edge region of the box lid 212 requires machining to provide the planar seal surface 210 and also the fixing holes 226 and locating holes 229. A pair of spaced apart scalloped regions (not shown) are optionally provided at the centre of each side region of the box lid 212 to allow the lid to be also welded to the upper edge of the box 200 to provide additional security. A circular bracket 250 is provided on the outer surface of the box lid 212 to allow a lifting device to attach to the box lid for manoeuvring the same during machining and/or onto or off the box 200. A centre hole is provided for mounting a filter assembly to allow air/moisture to leave the interior of the box when the lid is fitted in use.

As illustrated in Figure 3, a set of fixtures 400, 600, 800 according to certain embodiments of the present invention are located on a pallet 330 for use in a precision machining apparatus, such as the Taurus 30™ vertical milling machine by Waldrich Coburg GmbH. Such a machine is configured to use a two-pallet system allowing a set of fixtures to be located on each pallet in an opposed configuration. The set of fixtures includes a skip fixture 400 for supporting a skip 100 to be machined, a box fixture 600 for supporting a box 200 to be machined, and a lid fixture 800 for supporting a skip lid 112 and a box lid 212 to be machined. Each pallet 330 also supports a services unit 332 which includes a controller, a power management system, a hydraulic control system, vacuum pumps, back-up pumps, and control valves, etc. The controller may alternatively be located remotely from the pallet 330 and operably connect to the services unit 332 and in turn the fixtures 400,600,800 by way of one or more sockets or wirelessly.

As illustrated in Figure 4a, the skip fixture 400 includes a base plate 402 for supporting and coupling a main body assembly 404 of the skip fixture to the pallet 330. The base plate 402 has a plurality of pockets 403 and holes therein extending through the bottom surface to allow the bottom plate 402 to be securely attached to the pallet using suitable mechanical fasteners, such as a T-bolt and nut arrangement for engagement in corresponding slots of the pallet. Each pocket 403 allows access for a tool to tighten/loosen the nut located therein. The rectangular base plate 402 also includes a plurality of spaced apart locating elements (not shown) on its top surface for engagement with corresponding locating elements on the underside of the main body assembly 404 to allow for efficient installation and removal of the main body assembly 404 on and from the base plate 402. Aptly, a locating element is provided proximal each corner of the base plate and in the centre of the base plate. Each locating element on the base plate 402 comprises a recess and each locating element on the main body assembly 404 comprises a projection, or alternatively vice versa. Aptly, each locating assembly comprising the corresponding locating elements is provided by a Stark Speedy Classic™ zero-point mounting system by Roemheld. Such a zero-point mounting system is aptly hydraulically controlled. As illustrated in Figures 4a to 4d, the main skip body assembly 404 includes a base portion 410 attachable to the base plate 402 as described above, a pair of opposed side portions 412,414, a rear portion 416, and a top assembly 406 which is removably attachable to the main body assembly 404.

Figures 4b to 4d show the main body assembly 404 with the top assembly 406 removed therefrom.

Figures 4e and 4f respectively illustrate upper and lower views of the skip fixture top assembly 406.

As illustrated in Figure 4e, the top assembly 406 includes a rectangular support structure 420 and a plurality of attachment elements 422 mounted thereon for a lifting device (similar to that illustrated in Figure 9) to securely attach thereto for lifting and manoeuvring the top assembly when installing/removing the same on and from the main body assembly 404. The attachment elements 422 are aptly steel plates for correspondingly located electro-magnetic elements of a lifting device 980 (see Figure 9) to engage with.

As illustrated in Figure 4f, the top assembly 406 includes a locating element 424 in the form of a projection at each corner region on the underside thereof for engagement with a correspondingly shaped recess 426 in each upper corner of the main body assembly 404. The locating elements allow for efficient installation and removal of the top assembly on and from the main body assembly. Aptly, each locating assembly comprising the corresponding locating elements is provided by a Stark Speedy Classic™ zero-point mounting system by Roemheld.

The base portion 410, side portions 412,414, and rear portion 416 of the main body assembly 404, and the top assembly 406, provide a five-sided fixture for supporting a skip 100 located centrally therein. The front side of the skip fixture 400 is open to allow the skip 100 to be loaded therein and for the upper lip region 106 of the skip to extend outwardly from the fixture for machining (as illustrated in Figure 4a). As illustrated in Figures 4b to 4d, the main skip body assembly 404 includes a plurality of stop elements for locating the skip 100 in a repeatable position with respect to the X, Y, and Z axes of the skip when loaded into the skip fixture 400.

The plurality of stop elements includes a pair of spaced apart stop elements 430 mounted on the right-hand side one 414 of the side portions 412,414 of the main body assembly 404, four spaced apart stop elements 432 mounted on the base portion 410 of the main body assembly 404, and four spaced apart stop elements 434 mounted on the rear portion 416 of the main body assembly 404. Each stop element comprises a substantially planar stop surface for engagement with the respective face of the skip 100 when loaded in the fixture. Each stop element is aptly steel or the like to provide a positive stop surface.

The skip fixture 400 further includes a plurality of clamp members for locating and fixing the skip 100 in the desired position when abutting the stop elements. The plurality of clamp members optionally includes a pair of spaced apart linear clamp members 440 extending inwardly from the left-hand side one 412 of the side portions 412,414 of the main body assembly 404 each configured to engage the left-hand side of the skip and apply a force thereto to urge the skip in the X-axis and against the X-axis stop elements 430. The X-axis clamp members 440 are push actuators and are selectively driven by the controller. Aptly the clamp members 440 are hydraulically controlled but may be pneumatic or electrically controlled. Aptly, the end of each push clamp is steel or the like for engaging a respective outer face of the skip.

The plurality of clamp members optionally further includes a pair of spaced apart linear clamp members 442 extending downwardly from the support structure of the top assembly 406, as illustrated in Figure 4e. Each linear clamp member 442 is configured to engage a respective side of the skip and apply a force thereto to urge it in the Y-axis and against the Y-axis stop elements 432. The Y-axis clamp members 442 are hydraulic push actuators and are selectively driven by the controller.

The plurality of clamp members optionally further includes a set of three spaced apart lip clamp assemblies 444 mounted to each of the base portion 410 and side portions 412,414 of the main body assembly 404 and the support structure of the top assembly 406 to be locatable at the open side of the skip fixture 400 and engage with the lip region 106 of a skip 100 located therein.

As illustrated in Figures 4h and 4i, each lip clamp assembly 444 includes a rotatable clamp element 902 having a tapered free end 904 for engagement with the skip 100 and an opposite end 906 which is rotatably coupled to a linear actuator, such as a pneumatic piston, or motor. The clamp element 902 is rotatably coupled at around its midpoint with respect to a fixed body 908 of the clamp assembly 444 by a pair of spaced apart and parallel linkages 910. The linear actuator, and in turn the clamp element 902, is selectively moved by the controller to engage the clamp element 902 on the lip region of the skip and urge the same in the Z-axis and against the respective Z-axis stop elements 434. The clamp element 902 of each of the lip clamp assembly 444 is selectively rotatable between a retracted position (Figure 4h) and a deployed position (Figure 4i) to allow sufficient clearance for a skip 100 to be loaded into the skip fixture 400 when the clamp members are in the retracted position. Furthermore, each of the lip clamp assemblies 444 is configured to move its clamp element 902 away from the lip region 106 of the skip 100 to allow a cutting tool to machine the lip region proximal to that clamp assembly and then to re-engage the machined surface to re-clamp the skip.

Each lip clamp assembly 444 optionally further includes a linear clamp (not shown) located in the fixed body 902 to selectively apply a clamping force to the lip region of the skip in a direction substantially perpendicular to the respective outer face of the skip.

The lip clamp assemblies 444 are aptly hydraulically controlled but may alternatively be pneumatically or electrically controlled. Each clamp assembly 444 comprises a right-angle mount 912 for attaching, e.g. by welding, the clamp assembly to the respective portion of the main body assembly and top assembly of the skip fixture.

The skip fixture 400 optionally further includes a plurality of angle clamps for further fixing the skip 100 in the desired position when abutting the stop elements. The plurality of angle clamps includes three sets of angle clamps 446,448,450 extending inwardly from the base portion 410 at around 45 degrees to the horizontal plane to engage with the three lower edge regions of the skip when located in the skip fixture. Each of the side angle clamp sets 446,448 comprises two spaced apart angle clamps and the rear angle clamp set 450 comprises four spaced apart angle clamps.

The plurality of angle clamps optionally includes two further sets of angle clamps 452,454 extending inwardly from the rear portion 416 at around 45 degrees to the vertical plane to engage with the two vertically oriented rear edge regions of the skip when located in the skip fixture. Each of these sets of angle clamps comprises two spaced apart angle clamps.

The plurality of angle clamps optionally includes three further sets of angle clamps 456,457,458 extending downwardly from the support structure of the top assembly 406 at around 45 degrees to the horizontal plane to engage with the three upper edge regions of the skip when located in the skip fixture. As illustrated in Figure 4f, the right-hand side set 456 comprises two spaced apart angle clamps, the left-hand set 457 comprises three spaced apart angle clamps, and the rear set 458 comprises four spaced apart angle clamps.

As illustrated in Figure 4g, each angle clamp comprises a clamp member 445 configured to support a respective edge region of the skip. The clamp member 445 comprises a pair of fixed jaws 447,449 each having a substantially flat engagement surface 451 ,453 and defining an angle therebetween of 90-degree to engage with a respective face of the skip either side of the respective edge region. The

engagement surface does not extend the entire length of the respective jaw but instead each jaw includes a reduced region 455 extending from the engagement surface to where the jaws meet. The reduced regions allow the jaws not to engage with and apply pressure to the edge region of the skip itself. Each angled clamp member is rotatably coupled to a selectively controllable linear actuator 459, such as a hydraulic or pneumatic piston, by way of a swivel joint 461. Each linear actuator 459 is mounted to a right-angle mount 463 for attaching, e.g. by welding, to the respect portion of the main body assembly and top assembly of the skip fixture.

The skip fixture 400 further includes a plurality of airbag assemblies. The plurality of airbag assemblies includes a first side airbag assembly 460 mounted to the left-hand side portion 412 of the main body assembly 404 for engagement with the left-hand face of a skip located in the skip fixture, and a second side airbag assembly 470 mounted to the right-hand side portion 412 of the main body assembly 404 for engagement with the right-hand face of a skip located in the skip fixture. A third airbag assembly 480 is mounted on the base portion 410 of the main body assembly 404 for engagement with the lower face of a skip located in the skip fixture, and a fourth airbag assembly 490 is mounted on the rear portion 416 of the main body assembly 404 for engagement with the rear face of a skip located in the skip fixture. A fifth airbag assembly 500 is mounted on the underside of the top assembly 406 for engagement with the upper face of a skip located in the skip fixture. A sixth airbag assembly 510 is selectively locatable inside a skip when located in the skip fixture (see Figure 4a). The combination of the five outer airbags and the inner airbag supports the faces of the skip 100 when located in the skip fixture 400 and dampens/absorbs vibrations caused during machining.

The first, second and third airbag assemblies 460,470,480 for respective

engagement with the left-hand and right-hand faces and bottom face of the skip are substantially similar if not identical in configuration. As illustrated in Figure 5a, these airbag assemblies comprise an inflatable airbag 461 having a slotted through aperture 462 extending inwardly from a side surface of the airbag. The airbag 461 is mounted on a correspondingly shaped steel back plate 463 which is attachable to the respective portion, i.e. each side portion and base portion, of the main body assembly 404 of the skip fixture 400 by suitable means, such as bolts. A neoprene plate or layer 464 is attached by suitable means, such as adhesive, on the opposite surface of the airbag 461 to the back plate 463. The neoprene layer 464 is sized and shaped to engage a substantial portion of the respective skip face and protects the airbag. The neoprene layer will also help with vibration control by absorbing vibrational movement of the respective outer face of the skip with which it engages. The airbag assembly also includes a protective plate 465 extending from the back plate 463 which protects the airbag during the machining process, i.e. from chips and/or sparks. The protective plate 465 is steel or alternatively may be a hardened plastics material. The protective plate 465 may alternatively be attached to the airbag 461 by suitable means, e.g. bonding. The fourth airbag assembly 490 is illustrated in Figure 5b. This airbag assembly comprises an inflatable airbag 491 having a central through aperture 492. The airbag 491 is mounted on a correspondingly shaped steel back plate 493 which is attachable to the rear portion of the main body assembly 404 of the skip fixture 400 by suitable means, such as bolts. A neoprene plate or layer 494 is attached by suitable means, such as adhesive, on the opposite surface of the airbag 491 to the back plate 493. The neoprene layer 494 is sized and shaped to engage with a substantial portion of the base outer face of the skip and protects the airbag. The neoprene layer will also help with vibration control by absorbing vibrational movement of the respective outer face of the skip with which it engages.

The fifth airbag assembly 500 mounted on the underside of the top assembly 406 is substantially similar to the first, second and third airbag assemblies. The fifth airbag assembly is deeper than the first, second and third airbag assemblies when in an inflated state in that it has a greater range of movement between a deflated state and the inflated state. Alternatively, the fifth airbag assembly 500 may be identical to the first, second and third airbag assemblies.

The sixth airbag assembly 510 is illustrated in Figure 5c. This airbag assembly comprises an airbag 51 1 which is substantially box-like to be correspondingly sized and shaped to engage with the inner side faces and base face of the skip when in an inflated state. The airbag 51 1 is mounted on a top plate 512 having an attachment element 513, such as a bracket or connector, disposed in its centre around an inflation hole 517. The attachment element 513 may be used for connecting an inflation device to the airbag and/or for a lifting device to securely attach and manoeuvre the airbag into and out of the box before and after machining. The top plate 512 aptly comprises carbon fibre but may alternatively be made of a metal or plastics material. A bottom plate or layer 514 is attached to the bottom face of the airbag, opposed to the top face, by suitable means, such as bonding. The bottom plate 514 is made from 20mm thick neoprene and is sized and shaped to engage with a substantial portion of the inner base face of the skip and protects the airbag.

A 16mm thick neoprene plate or layer 515 is attached by suitable means, such as bonding, to each of the four side faces of the airbag. Each side plate 515 is sized and shaped to engage a substantial portion of the respective inner side face of the skip and protects the airbag. The neoprene layers, combined with the air inside each airbag, absorb/dampen vibrations caused during the machining process. When the central airbag 510 is located inside the skip and inflated to engage with the inner side faces and the inner base face of the skip, and the other five airbags 460, 470, 480, 490, 500 are inflated to engage with their respective outer face, each wall and the base of the skip are held between a respective outer airbag and the central inner airbag to thereby securely supported each wall and the base of the skip and prevent the same harmonically oscillating during the machining process.

The skip inner airbag assembly 510 may include a plurality of securing members, such as swing clamps, coupled to the top plate 512 which are configured to engage with the inner surface of the lip region and prevent the inner airbag assembly 510 pushing itself out of the skip during inflation. The securing members may be manually operated or automatically controlled by the controller to move between a retracted position (for when the airbag assembly is being loaded into or removed from the skip) and a deployed position (for when the airbag assembly is secured in the skip and ready for inflation). Such a security arrangement also ensures the airbag assembly remains in the skip in the event of an unintentional airbag deflation during the machining process.

Additionally, or alternatively, the skip inner airbag assembly 510 may comprise more than one selectively inflatable airbag 51 1 or a two-stage airbag. For example, a first airbag portion may inflate to engage on the four inner wall surfaces of the skip to hold the airbag assembly in position before a second airbag portion inflates to engage on the inner base surface of the skip. The first and second airbag portions may be provided by the same or separate airbags.

Aptly, each airbag is a composite of a woven rubberised material and carbon fibre and flexible Kevlar™ outer surface.

As illustrated for example in Figure 4f in respect of the top assembly air bag, a sensor array 550 is provided in the aperture of the airbag and mounted on the support structure of the top assembly 406. As illustrated in Figure 5d, the sensor array 550 comprises a vibration sensor 551 mounted on a platform 552 which is coupled to the support structure of the top assembly 406 by a piston assembly 554 to move the platform towards or away from the respective skip face. A fixed stop element 556 and a proximity sensor or switch 558 are also mounted on the platform 552 to engage with the respective skip face. This arrangement confirms the platform and in turn the vibration sensor is located correctly with respect to the outer face of the skip, and also ensures any outward bowing of the outer face is

eliminated/minimised before machining commences. The same arrangement is provided in the slotted apertures of the side and rear airbag assemblies

460,470,480, 500. Each vibration sensor is configured to sense at least one parameter of a vibration caused in the respective skip face during the machining process, such as frequency and/or amplitude, and the controller is configured to selectively adjust at least one parameter of the fixture assembly and/or the machining process, such as clamp force, airbag pressure and/or the machining speed and/or feed rate of a machine tool, responsive to the sensed vibration.

As illustrated in Figures 6a to 6d, the box fixture 600 has a similar configuration to the skip fixture 400.

The box fixture 600 includes a base plate 602 for supporting and coupling a main body assembly 604 of the box fixture to the pallet 330. The base plate 602 has a plurality of pockets 603 and holes therein extending through the bottom surface to allow the bottom plate 602 to be securely attached to the pallet using suitable mechanical fasteners, such as a T-bolt and nut arrangement for engagement in corresponding slots of the pallet. Each pocket 603 allows access for a tool to tighten/loosen the nut located therein. The rectangular base plate 602 also includes a plurality of spaced apart locating elements (not shown) on its top surface for engagement with corresponding locating elements on the underside of the main body assembly 604 to allow for efficient installation and removal of the main body assembly 604 on and from the base plate 602. Aptly, a locating element is provided proximal each corner of the base plate and in the centre of the base plate. Each locating element on the base plate 602 comprises a recess and each locating element on the main body assembly 604 comprises a projection, or alternatively vice versa. Aptly, each locating assembly comprising the corresponding locating elements is provided by a Stark Speedy Classic™ zero-point mounting system by Roemheld.

As illustrated in Figure 6a, the box main body assembly 604 includes a base portion 610 attachable to the base plate 602 as described above, a pair of opposed side portions 612,614, a rear portion 616, and a top assembly 606 which is removably attachable to the main body assembly 604. Figures 6b to 6d show the main body assembly 604 with the top assembly 606 removed. Figures 6e and 6f illustrate upper and lower views of the box fixture top assembly 606 respectively.

As illustrated in Figure 6e, the top assembly 606 includes a rectangular support structure 620 and a plurality of attachment elements 622 mounted thereon for a lifting device 980 (see Figure 9) to securely attach thereto for lifting and manoeuvring the top assembly when installing/removing the same on and from the main body assembly 604. The attachment elements 622 are aptly steel plates for

correspondingly located electro-magnetic elements of a lifting device to engage with.

As illustrated in Figure 6f, the top assembly 606 includes a locating element 624 in the form of a projection at each corner region thereof for engagement with a correspondingly shaped recess 626 in each upper corner of the main body assembly 604. The locating elements allow for efficient installation and removal of the top assembly on and from the main body assembly. Aptly, each locating assembly comprising the corresponding locating elements is provided by a Stark Speedy Classic™ zero-point mounting system by Roemheld.

The base portion 610, side portions 612,614, and rear portion 616 of the main body assembly 604, and the top assembly 606, provide a five-sided fixture for supporting a box 200 located centrally therein. The front side of the box fixture 600 is open to allow the box to be loaded therein and for the upper edge region 206 of the box 200 to extend outwardly from the box fixture for machining.

As illustrated in Figures 6b and 6c, the box main body assembly 604 includes a plurality of stop elements for locating the box 200 in a repeatable position with respect to the X, Y, and Z axes of the skip when loaded into the box fixture 600. The plurality of stop elements includes a pair of spaced apart stop elements 630 mounted on the right-hand side one 614 of the side portions 612,614 of the main body assembly 604, four spaced apart stop elements 632 mounted on the base portion 610 of the main body assembly 604, and four spaced apart stop elements 634 mounted on the rear portion 616 of the main body assembly 604. Each stop element comprises a substantially planar stop surface for engagement with the respective face of the box 200 when loaded in the box fixture. Each stop element is aptly steel or the like.

The box fixture 600 further includes a plurality of clamp members for locating and fixing the box 200 in the desired position when abutting the stop elements. The plurality of clamp members optionally includes a pair of spaced apart linear clamp members 640 extending inwardly from the left-hand side one 612 of the side portions 612,614 of the main body assembly 604 each configured to engage the left-hand side of the box and apply a force thereto to urge the box in the X-axis and against the X-axis stop elements 630. These X-axis clamp members 640 are hydraulic push actuators and are selectively driven by the controller.

The plurality of clamp members optionally further includes a pair of spaced apart linear clamp members 642 extending downwardly from the support structure of the top assembly 606, as illustrated in Figure 6e. Each linear clamp member 642 is configured to engage the upper side of the box when located in the box fixture and apply a force thereto to urge it in the Y-axis and against the Y-axis stop elements 632. These Y-axis clamp members 642 are hydraulic push actuators and are selectively driven by the controller.

A pair of further spaced apart linear clamp members 641 acting in the X-axis are provided on each of the side portions 612,614 at the opening of the box fixture such that they engage with the upper edge region 206 of box 200 when located in the box fixture 600. These additional X-axis clamp members 641 are hydraulic push actuators and are selectively driven by the controller.

A pair of further spaced apart linear clamp members 643 acting in the Y-axis are optionally provided on the base portion 610 of the main body assembly 604 at the opening of the box fixture such that they engage with the upper edge region 206 of box 200 when located in the box fixture 600. A pair of Y-axis linear clamp members 645 are also optionally provided on the top assembly 606 at the opening of the box fixture when the top assembly is mounted on the main body assembly such that these additional Y-axis linear clamp members 645 engage with the upper edge region 206 of box 200 when located in the box fixture 600. The Y-axis clamp members 643,645 are hydraulic push actuators and are selectively driven by the controller.

The plurality of clamp members optionally further includes a set of three spaced apart upper edge clamp assemblies 644 mounted to each of the base portion 610 and side portions 612,614 of the main body assembly 604 and the support structure of the top assembly 606 to be locatable at the open side of the box fixture 600 and engage with the upper edge region 206 of a box 200 located therein. Each set of three upper edge clamp assemblies 644 are located in an alternating arrangement with the respective pairs of X-axis and Y-axis linear clamp members 641 ,643 located at the opening of the fixture 600. Like the rim clamp assemblies 444 of the skip fixture 400, each upper edge clamp assembly 644 of the box fixture 600 comprises a rotatable clamp element 902 (see for example Figures 9a and 9b) which is selectively moveable between a retracted position and a deployed position by the controller. When in the deployed position, the clamp element 902 engage the upper edge region of the box to urge the same in the Z-axis and against the Z-axis stop elements 634 to be in the desired position for machining. The retracted position provides clearance for a box 200 to be loaded into the box fixture 600. Furthermore, each of the rotatable Z-axis clamps 644 is configured to move away from the upper edge region 206 of the box 200 to allow a cutting tool to machine the upper edge region proximal to that clamp assembly and also to re-engage the machined surface to re-clamp the box. The upper edge clamp assemblies 644 are aptly hydraulically controlled but may alternatively be pneumatically or electrically controlled. Each clamp assembly 644 comprises a right-angle mount 912 for attaching, e.g. by welding, the clamp assembly to the respective portion of the main body assembly and top assembly of the box fixture. The box fixture 600 optionally further includes a plurality of angle clamps for further fixing the box 200 in the desired position and orientation when abutting the stop elements. The plurality of angle clamps includes three sets of angle clamps

646,648,650 extending inwardly from the base portion 610 to engage with the three lower edge regions of the box when located in the box fixture. The plurality of angle clamps optionally includes two further sets of angle clamps 652,654 extending inwardly from each side of the rear portion 616 to engage with the two vertically oriented rear edge regions of the box when located in the box fixture. The plurality of angle clamps optionally includes three further sets of angle clamps 656,657,658 extending downwardly from the sides and rear portions of the support structure of the top assembly 606 to engage with the three respective upper edge regions of the box when located in the box fixture.

In a similar manner to the angle clamps of the skip fixture 400, each angle clamp of the box fixture 600 comprises a clamp member (not shown) configured to support a respective edge region of the box. The angled clamp member comprises a pair of substantially flat engagement surfaces angularly spaced apart by 90-degree to engage with a respective face of the box either side of the respective edge region whilst not to engage with and apply pressure to the edge region itself. Each clamp portion is rotatably coupled to a selectively controllable actuator, such as a hydraulic or pneumatic piston, by way of a swivel joint.

As an alternative embodiment, each angle clamp as illustrated for example in Figure 4g may be replaced by a pair of linear clamps each configured to engage on the flat outer surface of a respective one of the sides adjacent to a corner edge region of the box, e.g. a first linear actuator of the pair may selectively engage a first clamp foot on a first outer surface of the box and be oriented in a substantially horizontal direction, and a second linear actuator of the pair may selectively engage a second clamp foot on a second outer surface of the box perpendicular to the first outer surface and be oriented in a substantially vertical direction. This alternative clamp arrangement may also be used for the skip fixture.

An alternative embodiment of each lip clamp assembly for the skip fixture and/or box fixture is illustrated in Figure 19. Each lip clamp assembly 1900 includes a rotatable swing arm 1902 selectively rotatable with respect to the skip or box between a first position and a second position by an actuator, such as an electric motor or a pneumatic or hydraulic drive, or the like. The swing arm 1902 is also translatable inwardly and outwardly along its rotational axis 1903 such that it has a clamping stroke of around 25mm. A clamp foot 1904 is also provided proximal the free end region of the swing arm 1902 which is selectively moveable by a suitable linear actuator 1906 in a direction substantially parallel to the rotational axis of the swing arm. In use, the swing arm is selectively rotated from the first position (A) to a pre clamp position (B). The swing arm is then selectively translated towards the lip region of the box or skip to a clamped position (C) such that the clamp foot engages therewith. The clamp foot is then optionally translated towards the lip region to apply a further clamping force thereto.

The box fixture 600 further includes a plurality of airbag assemblies. The plurality of airbag assemblies includes a first side airbag assembly 660 mounted to the left-hand side portion 612 of the main body assembly 604 for engagement with the left-hand face of a box located in the box fixture, and a second side airbag assembly 670 mounted to the right-hand side portion 612 of the main body assembly 604 for engagement with the right-hand face of a box located in the box fixture. A third airbag assembly 680 is mounted on the base portion 610 of the main body assembly 604 for engagement with the lower face of a box located in the box fixture, and a fourth airbag assembly 690 is mounted on the rear portion 616 of the main body assembly 604 for engagement with the rear face of a box located in the box fixture.

A fifth airbag assembly 700 is mounted on the underside of the top assembly 606 for engagement with the upper face of a box located in the box fixture. A sixth airbag assembly 710 is selectively locatable inside a box when located in the box fixture. The combination of the five outer airbags and the inner airbag supports the faces of the box 200 when located in the box fixture 600 and dampens/absorbs vibrations caused during machining.

The first, second and third airbag assemblies 660,670,680 for respective

engagement with the left-hand and right-hand faces and bottom face of the box are substantially similar if not identical in configuration. As illustrated in Figure 7a, these airbag assemblies comprise an inflatable airbag 661 having a central through aperture 662. The substantially rectangular shaped airbag 661 is mounted on a correspondingly shaped steel back plate 663 which is attachable to the respective portion, i.e. each side portion and base portion, of the main body assembly 604 of the box fixture 600 by suitable means, such as bolts. A neoprene plate or layer 664 is attached by suitable means, such as adhesive, on the opposite surface of the airbag 661 to the back plate 663. The neoprene layer 664 is sized and shaped to engage a substantial portion of the respective box face and protects the airbag.

The fourth airbag assembly 690 is illustrated in Figure 7b. This airbag assembly comprises an inflatable airbag 691 having a central through aperture 692. The substantially octagonal shaped airbag 690 is mounted on a correspondingly shaped steel back plate 693 which is attachable to the rear portion of the main body assembly 604 of the box fixture 600 by suitable means, such as bolts. A neoprene plate or layer 694 is attached by suitable means, such as adhesive, on the opposite surface of the airbag 691 to the back plate 693. The neoprene layer 694 is sized and shaped to engage with a substantial portion of the base outer face of the box and protects the airbag. The rear airbag assembly 690 also includes a protective plate 695 extending at right angles from every other edge of the back plate 693 to protect the respective sides of the airbag during the machining process, i.e. from chips and/or sparks. The protective plate 695 is steel or alternatively may be another metal or a hardened plastics material. The protective plates 695 may alternatively be attached to the airbag 691 by suitable means, e.g. bonding, and/or extend from all the edges of the back plate 693 depending on the proximity of machining.

The fifth airbag assembly 700 mounted on the underside of the top assembly 606 is substantially similar to the first, second and third airbag assemblies. The fifth airbag assembly is deeper than the first, second and third airbag assemblies when in an inflated state in that it has a greater range of movement between a deflated state and the inflated state. Alternatively, the fifth airbag assembly 500 may be identical to the first, second and third airbag assemblies.

As illustrated in Figure 20, an alternative embodiment of the fourth airbag assembly 2690 may include a backplate 2693 having side regions 2695 extending perpendicularly from each edge region of the backplate to fully contain and protect the airbag 2691 mounted on the backplate. Each edge region may be integral with the backplate 2693 or may be a separate component attached to the backplate.

Each edge region may be formed from a metal or plastic, or aptly may be formed from bristles to form a brush edge region which desirably protects the outer airbag whilst providing each edge region with a degree of flex/resilience when the airbag is being inflated and/or when the airbag is deflated and a box to be machined is being loaded into the box fixture. This brush arrangement may also be used for the side airbag assemblies of the box fixture, and also for the skip fixture.

The airbag 2691 includes a neoprene plate or layer 2694 attached by suitable means, such as adhesive, on the opposite surface of the airbag 2691 to the back plate 2693. The backplate 2693 is aptly aluminium and is around 10mm thick, and the neoprene layer 2694 is also around 10mm thick. An uppermost one of the side regions 2695 may include a first fixation element 2700, such as a post, hook or loop or the like, for attaching a first end of a resilient element (not shown), such as a spring, elastic or rubber element or the like, to and the airbag 2691 may include a second fixation element 2702, such as a tag, hook or loop or the like, for attaching a second end of the resilient element to. Aptly, the upper side region includes a pair of spaced apart first fixation elements and an upper region of the airbag includes a corresponding pair of second fixation elements such that a pair of resilient elements couple the airbag to the upper side region. In use, the resilient element/s support the rear airbag and prevent the same drooping under its own weight. This arrangement for supporting a vertically oriented airbag may also be used for the side airbag assemblies of the box fixture, and also for the skip fixture.

The sixth airbag assembly 710 is illustrated in Figure 7c. This airbag assembly comprises an airbag 71 1 which is correspondingly sized and shaped to engage with the inner side faces and base face of the box when in an inflated state. The airbag 71 1 is mounted on a top plate 712 having an attachment element 713, such as a bracket or connector, disposed in its centre around an inflation hole 717. The attachment element 713 may be used for connecting an inflation device to the airbag and/or for a lifting device to securely attach and manoeuvre the airbag into and out of the box before and after machining. The top plate 712 aptly comprises carbon fibre but may alternatively be made of a metal or plastics material. A bottom plate or layer 714 is attached to the bottom face of the airbag, opposed to the top face, by suitable means, such as bonding. The bottom plate 714 is made from 20mm thick neoprene and is sized and shaped to engage with a substantial portion of the inner base face of the skip and protects the airbag. A 16mm thick neoprene plate or layer 715 is attached by suitable means, such as bonding, to each of the four side faces of the airbag. Each side plate 715 is sized and shaped to engage a substantial portion of the respective inner side face of the box and protects the airbag. The neoprene layers, combined with the air inside each airbag, absorb/dampen vibrations caused during the machining process. When this central airbag 710 is located inside the box and inflated to engage with the inner side faces and the inner base face of the box, and the other five airbags 660, 670, 680, 690, 700 are inflated to engage with their respective outer face, each wall and the base of the box are held between a respective outer airbag and the central inner airbag to thereby securely supported each wall and the base of the box and prevent the same harmonically oscillating during the machining process.

The box inner airbag assembly 710 may include a plurality of securing members, such as swing clamps, coupled to the top plate 712 which are configured to engage with the inner surface of the lip region and prevent the inner airbag assembly 710 pushing itself out of the box during inflation. The securing members may be manually operated or automatically controlled by the controller to move between a retracted position (for when the airbag assembly is being loaded into or removed from the box) and a deployed position (for when the airbag assembly is secured in the box and ready for inflation). Such a security arrangement also ensures the airbag assembly remains in the box in the event of an unintentional airbag deflation during the machining process.

Additionally, or alternatively, the box inner airbag assembly 710 may comprise more than one selectively inflatable airbag 71 1 or a two-stage airbag. For example, a first airbag portion may inflate to engage on the four inner wall surfaces of the box to hold the airbag assembly in position before a second airbag portion inflates to engage on the inner base surface of the box. The first and second airbag portions may be provided by the same or separate airbags. An alternative embodiment for the box inner airbag assembly is illustrated in Figures 21 a and 21 b. The inner airbag assembly 2100 includes an inner frame 2102 for supporting five airbags (four airbags 2104,2106,2108,2110 shown) mounted thereon. The frame may comprise inner cross braces 2103 for additional strength and rigidity. The frame 2102 is mounted on a backplate 21 12 which is aptly aluminium and around 10mm thick. Four of the five airbags are for engaging with a respective inner side wall surface of the box in use and the fifth airbag 21 10 is for engaging with the inner base surface of the box in use. Each airbag is mounted to an airbag backplate 21 14 which is attached to the frame 2102 by suitable means, such as bolts. Each airbag backplate 21 14 is aptly aluminium and around 10mm thick. Each airbag includes a neoprene plate or layer 21 16 attached by suitable means, such as adhesive, on the opposite surface of the airbag to its backplate. The neoprene layer is around 10mm thick.

A protection flange 2115 extends outwardly from the edges of the frame backplate 21 12 to protect the airbags from sparks, swarf etc. during a machining process. The protection flange 21 15 may be formed from a metal or plastic, or aptly may be formed from bristles to form a brush edge region which desirably protects the inner airbags whilst providing the flange with a degree of flex/resilience when the inner airbag is being loaded into the box fixture and past the lip region thereof. This flange arrangement may also be used for the skip fixture inner airbag assembly.

As illustrated in Figure 21 b, a plurality of rotatable clamp members 21 17 are pivotally attached to the backplate 21 12 and configured to be rotatable between engaged and disengaged positions with respect to an inner surface of the lip region of the box. When the inner airbag assembly is loaded into a box to be machined, the clamp members 21 17 are manually rotated from the disengaged position to the engaged position (as illustrated) such that when at least the fifth airbag is inflated to engage with the base of the box, the inner airbag assembly is urged outwardly with respect to the box and the clamp members are urged against the inner surface of the lip region. This arrangement prevents the inner airbag assembly from being forced out of the box when at least the fifth airbag is inflated. When the inner airbag assembly is to be removed from the box after a machining process, the clamp members 2117 are manually moved to the disengaged position. Each clamp member may include a snap-lock mechanism, such as a nipple or spring-loaded ball engageable in a recess on the back plate 2112, to retain the clamp member in the engaged or disengaged position. This inner airbag clamp member arrangement may also be used for the skip fixture inner airbag assembly.

Each airbag is coupled by a respective airline to a compressed air source and/or pump for selectively inflating the airbag. Each airline may also be used to exhaust gas, e.g. air, from the respective airbag when the same is being deflated. As illustrated in Figure 21 a, the airlines (not shown) extend from each airbag and terminate in a collar 21 16 mounted to the backplate 21 14. Each airline may be supported by the frame 2102. After the airbag assembly 2100 has been inserted into the box, the airlines are coupled to the air source for selective and controlled inflation by a controller.

To ensure each airline is coupled to a correct one of a plurality of input airlines (not shown) connected to the air source, a connector 2150 as illustrated in Figure 22 is used. The connector 2150 includes a substantially circular body portion 2152 having five holes 2154 for supporting five female connector portions (not shown) attached in use to respective male connector portions 2155 supported by the central collar 21 16 on the backplate 21 12 of the inner airbag assembly 2100. The connector 2150 further includes a central keyed through hole 2156 for mounting on a

correspondingly shaped keyed spigot 2158 extending from the collar 21 16 on the frame backplate 2112, as illustrated in Figure 21 b. The keyed relationship between the spigot and the hole ensures the connector can only be mounted on the spigot in a specific predetermined orientation thereby ensuring each airbag airline is coupled to a correct one of the input airlines. The connector further includes a pair of handles 2160 for handling the connector in use. The connector is aptly lockable to the backplate or collar when coupled thereto to prevent the same unintentionally coming away from the backplate or collar and the airlines unintentionally becoming uncoupled. The connector efficiently, correctly and consistently couples each airbag to a respective and corresponding one of the input airlines for selectively

inflating/deflating each airbag as and when required, such as in a predetermined order, stages and/or rate/pressure. This box fixture inner airbag assembly arrangement eliminates any risk of a single, large inner airbag drooping under its own weight which could make it difficult to insert/remove the inner airbag assembly into/from the box and without damaging the airbag itself. Furthermore, it provides a stronger internal bag system and support, each airbag thereof can be independently inflated/deflated as required to selectively adjust the clamping load on the respective box wall, and the remaining airbags will continue to provide a clamping load on the box in the unlikely event one airbag fails. This box fixture inner airbag assembly may also be used for the skip fixture inner airbag assembly.

In the same or similar manner as illustrated in Figure 5d for the skip fixture outer airbag assemblies, a vibration sensor is located in the central aperture 662,692 of each airbag of the outer airbag assemblies 660, 670, 680, 690, 700. The vibration sensor is mounted on a platform which is coupled to the base portion 610 of the main body assembly 604 of the box fixture 600 by a piston assembly to move the platform towards or away from the respective box face. A fixed stop element and a proximity sensor or switch are also mounted on the platform to engage with the respective box face.

Figure 8a illustrates the lid fixture 800 for supporting a skip lid 1 12 and a box lid 212 to be machined on both sides in two separate operations. Figure 8a shows a box lid 212a supported on the left-hand side of the fixture 800 with its upper surface facing outwardly and a box lid 212b supported on the right-hand side of the fixture 800 with its inner surface facing outwardly. Likewise, a skip lid 1 12a, 1 12b is supported on the other face of the fixture 800 in the same two orientations as the box lids. In use, the box lid is located on one side of the fixture for a first machining operation to one of its surfaces and then moved to the other side of the fixture for a second machining operation to its other surface. Likewise, on the opposite surface of the fixture, the skip lid is located on one side of the fixture for a first machining operation to one of its surfaces and then moved to the other side of the fixture for a second machining operation to its other surface. Alternatively, a first box lid having its upper surface facing outwardly may be mounted on the lid fixture next to a second box lid having it lower surface facing outwardly and the two box lids may be machine at the same time. The same may apply for machining two skip lids.

As illustrated in Figure 8b, the lid fixture 800 includes a substantially rectangular main support body 802 having a first surface 804 and an opposed second surface 806. A plurality of spaced apart pockets 808 are provided along the lower edge region of the main support body 802 and each pocket includes a hole extending through the lower surface of the main body. This arrangement allows the main support body 802 to be securely attached on its long lower edge to the pallet 330 using suitable mechanical fasteners, such as a T-bolt and nut arrangement for engagement in corresponding slots of the pallet. Each pocket allows access for a tool to tighten/loosen the nut located therein.

The rectangular main support body 802 also includes a plurality of spaced apart locating elements 810 on each of the first and second surfaces 804,806 for engagement with corresponding locating elements on a correspondingly flat base surface of a vacuum plate 820, 822, 824, 826 for supporting a respective one of the skip lid 100 and box lid 200, as described further below. Aptly, four locating elements 810 are arranged in a square to each align with a corresponding locating element proximal each corner of the corresponding vacuum plate. Each locating element 810 on the main support body 802 comprises a recess and each locating element on each vacuum plate 820, 822, 824, 826 comprises a projection, or alternatively vice versa. Aptly, each locating assembly comprising the corresponding locating elements is provided by a Stark Speedy Classic™ zero-point mounting system by Roemheld. Such an arrangement allows for efficient installation and removal of the vacuum plates 820, 822, 824, 826 on and from the main support body 802 of the lid fixture 800. Alternatively, other forms of mounting system may be used to securely mount the vacuum plates to the main support body, such as electro magnetic, mechanical fasteners, solenoids, or the like. Further alternatively, the vacuum plates may be an integral part of the main body. The main body is aptly steel or the like.

The main support body 802 further includes a plurality of vacuum ports 828 coupled to a vacuum pump or the like operably connected to the controller for securely mounting the skip lid 112 and box lid 212 to the support body for machining, as described further below. The support body 802 may comprise a rectangular support frame with the first and second rectangular surfaces 804,806 fixed thereto to provide a substantially hollow interior for creating a negative pressure therein and in turn the vacuum to mounting the skip lid and box lid to the support body for machining.

Alternatively, the support body 802 may comprise a lattice of hollow square section beam members which provide the first and second surfaces 804,806 for mounting the respective box/skip lid on and also a hollow interior passageway for coupling the vacuum ports 828 to a suitable vacuum pump for creating the negative pressure and in the vacuum.

Figure 8c illustrates a first skip vacuum plate 820 for supporting the skip lid 1 12a in a first orientation. Figure 8d shows the skip lid 1 12a mounted to the first skip vacuum plate 820 with its inner surface facing outwardly for machining.

The first skip vacuum plate 820 is substantially square and includes a recessed vacuum region 832 surrounding a recessed centre region 834. The recessed centre region 834 is substantially circular and accommodates the raised centre region (lifting bracket) of the skip lid when the lid is mounted on the vacuum plate. The recessed vacuum region 832 has a substantially octagonal outer edge 836 and a substantially circular inner edge 838. The outer edge 836 has alternating long and short portions. Alternatively, the recessed vacuum region 832 may be any suitable shape and size for securely mounting a skip lid to the vacuum plate for machining. The recessed vacuum region 832 is separated from the recessed centre region 834 by a raised annular region 840 which engages with the skip lid 1 12 when mounted to vacuum plate 820. The inner and outer edges of the vacuum region include a continuous seal to ensure an effective vacuum is created in the vacuum region when the skip lid is mounted on the vacuum plate. Four spaced apart vacuum ports 832 are provided in the vacuum region 832 and are arranged at 0, 90, 180, and 270 degrees relative to the centre and edges of the plate 820. Each vacuum port 832 extends through the vacuum plate and communicates with a corresponding one of the vacuum ports 828 of the main support body 802. An O-ring or the like is provided around each vacuum port 832 in the vacuum plate 820 to provide a seal between the plate and the main support body. A pair of apertures 842 are provided outboard of each short edge of the octagonal vacuum region 832 to accommodate a drill bit when corresponding fixing holes 843 are being drilled in the skip lid. Furthermore, the skip vacuum plate 820 includes a plurality of spaced apart projections 844 for engagement with the edge of the skip lid to support and locate the same in the desired position and orientation on the vacuum plate 820.

Figure 8e illustrates a second skip vacuum plate 822 for supporting the skip lid 1 12b in a second orientation. Figure 8f shows the skip lid 1 12b mounted to the second skip vacuum plate 822 with its outer surface facing outwardly for machining.

The second skip vacuum plate 822 is substantially square and includes a recessed vacuum region 852 surrounding a recessed centre region 854. The recessed vacuum region 852 is substantially octagonal having alternating long and short sides. The recessed centre region 854 is substantially circular and is separated from the vacuum region by a raised annular region 856. A continuous sealing element is provided at the inner and outer peripheral boundaries of the vacuum region 852 to ensure an effective seal is achieved when the skip lid 1 12 is supported on the second skip vacuum plate 822. Four spaced apart vacuum ports 858 are provided in the vacuum region 852 and are arranged at 0, 90, 180, and 270 degrees relative to the centre and edges of the plate 830. Each vacuum port 858 extends through the vacuum plate and communicates with a corresponding one of the vacuum ports 828 of the main support body 802. An O-ring or the like is provided around each vacuum port 858 in the vacuum plate 822 to provide a seal between the plate and the main support body. A pair of location pins 860 are provided to engage with corresponding location holes in the skip lid 1 12 to thereby support the same on the second skip vacuum plate in the desired position and orientation.

Figure 8g illustrates a first box vacuum plate 824 for supporting a box lid 212a in a first orientation. Figure 8h shows the box lid 212a mounted to the first box vacuum plate 824 with its inner surface facing outwardly for machining. The first box vacuum plate 824 is substantially square and includes four spaced apart recessed vacuum regions 862 surrounding a recessed centre region 864. The recessed centre region 864 is substantially circular and configured to accommodate the raised centre region (lifting bracket) of the box lid (see Figure 2c) when the box lid is mounted on the vacuum plate. Each recessed vacuum region 862 is

substantially triangular but may be any suitable shape and size for securely mounting a box lid to the first box vacuum plate for machining. The vacuum regions are arranged to support each quadrant of the box lid. The recessed vacuum regions 862 and the recessed centre region 864 are surrounded by raised planar regions which engage with the box lid when mounted to the vacuum plate 824. A peripheral channel 866 is provided in the vacuum plate to accommodate the edge regions of the box lid. The peripheral channel 866 comprises a plurality of spaced apart holes 868 for accommodating a drill bit when the corresponding fixing and locating holes are being machined in the box lid. The inner and outer edges of each vacuum region 862 include a continuous seal to ensure an effective vacuum is created in each vacuum region when the box lid is mounted on the first box vacuum plate. A vacuum port 870 is provided in the centre of each vacuum region 862 which extends through the vacuum plate and communicates with a corresponding one of the vacuum ports 828 of the main support body 802. An O-ring or the like is provided around each vacuum port 870 in the first box vacuum plate 824 to provide a seal between the plate and the main support body. The first box vacuum plate 824 further includes a plurality of spaced apart projections 872 for engagement with a corresponding edge of the box lid to support and locate the same in the desired position and orientation on the first box vacuum plate 824.

Figure 8i illustrates a second box vacuum plate 826 for supporting the box lid 212b in a second orientation. Figure 8j shows the box lid 212b mounted to the second box vacuum plate 826 with its outer surface facing outwardly for machining.

The second box vacuum plate 826 includes a substantially square recessed vacuum region 882 separated from a substantially circular recessed centre region 884 by an annular raised region 886. A continuous seal element is provided at each of the inner and outer boundaries of the vacuum region to provide an effective seal when the box lid is mounted to the second box vacuum plate. A vacuum port 888 is provided proximal each corner of the vacuum region 882 which extends through the vacuum plate and communicates with a corresponding one of the vacuum ports 828 of the main support body 802. An O-ring or the like is provided around each vacuum port 888 in the second box vacuum plate 826 to provide a seal between the plate and the main support body. A pair of location pins 890 are provided to engage with corresponding location holes in the box lid 212 to thereby support the same on the second box vacuum plate in the desired position and orientation.

Each vacuum plate 820,822,824,826 further includes at least one identification element to allow the controller to determine which machining program to execute corresponding to the configuration of the vacuum plate. For example, the vacuum plate may be configured for machining a skip lid or a box lid and one type of lid selected from a plurality of differently configured lids for use on different skips or boxes. The identification element is aptly a hole 900 (see for example Figure 8e) for a probe of the machine to detect and measure, such that a dimension of the hole, e.g. diameter, corresponds with a specific machining program. Flowever, the identification element may alternatively comprise a barcode, label, NFID,

digits/letters stamped or punched in the plate, or other visual and/or tactile ID element to determine a machining program to be executed by the controller.

A pressure sensor is aptly located in each airbag and operably coupled to the controller to allow the same to monitor an internal pressure of a respective one of the airbags and adjust the internal pressure accordingly to thereby adjust a force being applied to the corresponding inner or outer face of the skip or box.

A method of locating and fixing a skip 100 to be machined in the skip fixture 400 according to certain embodiments of the present invention will now be described.

The skip 100 is oriented on its side and a lifting device 1000 as illustrated in Figure 10 is located inside the skip via its opening. The lifting device 1000 includes a support frame 1002 and a plurality of spaced apart lifting pads 1004 mounted thereon and arranged in a square configuration to adequately support and lift the skip via one inner face thereof. Within the square defined by the lifting pads is a plurality of suction elements 1006 also arranged in a square configuration. The suction elements securely hold the skip with respect to the lifting device. A lifting ring 1008 is coupled to the support frame by three lifting bars 1010 to allow a crane or the like to lift the lifting device and a skip supported thereon. A counterweight 1012 is slidably mounted on the support frame to ensure the lifting operation is balanced.

The skip 100 is loaded into the skip fixture 400 without the top assembly 406 mounted thereon such that its opening is facing outwardly from the skip fixture. The skip is located on the Y-axis stop elements 432 and is optionally moved by the lifting device to locate the skip 100 close to or against the X-axis stops 430 and the Z-axis stops 434.

The top fixture assembly 406 is then lifted via the metal plates 422 thereof by the lifting device 980 illustrated in Figure 9 onto the main body assembly 404 of the skip fixture 400 and securely attached thereto by the zero-point hydraulic mounting system. The lifting device 980 includes a main frame 982 and a plurality of electro magnetic elements 984 suspended therefrom for selective attachment by the controller or other control means with the metal plates 422 of the top assembly 406. The lifting device 980 is coupled to a hoist or crane by way of a lifting ring (not shown) coupled to the main frame by lifting bars 986.

The X, Y and Z datums are then located. The linear X-axis push clamps 440 are actuated to urge the skip against the X-axis stops 430 and to apply a first

predetermined clamp force to the skip thus locating the same in a desired position on the X-axis. The lip clamp assemblies 444 are then actuated to urge the skip against the Z-axis stops 434 and to apply a first predetermined clamp force to the skip thus locating the same in a desired position on the Z-axis. Aptly, only the rotatable clamp elements 902 of the lip clamp assemblies 444 located opposite the respective Z-axis stops 434 are actuated to ensure a balanced first clamping operation in the Z-axis is achieved. The linear Y-axis push clamps 442 of the top assembly 406 are then actuated to urge the skip against the Y-axis stops 432 and to apply a first

predetermined clamp force to the skip thus locating the same in a desired position on the Y-axis. The skip is now located in a desired position with respect to all three axes and is clamped at a first predetermined clamp force. The desired position is confirmed by the proximity sensors 558 of the sensor arrays 550 and/or additional proximity sensors located on the X, Y and Z axes, such as on each stop element. The proximity sensor/s may also be used to indicate to the controller that a skip is present in the skip fixture prior to machining commencing.

The remaining clamps are now activated to securely fix the skip in the desired position. The linear push clamps of the lip clamp assemblies 444 are activated to engage against the outside face of the lip region of the skip and apply a second predetermined clamp force thereto in the X and Y directions. The remaining rotatable clamp elements 902 of the lip clamp assemblies 444 are activated to apply a second predetermined pressure to the upper face of the lip region of the skip in the Z direction. The 45-degree angle clamps are then activated to apply a first predetermined clamp force to a respective side face of the skip proximal a corner region thereof and in a respective direction. Aptly, the first clamp force of the angle clamps is the same or similar to the first clamp force of the linear clamps. Aptly, the force applied by each clamp is selectively adjustable by the controller responsive to a signal from at least one proximity sensor, a force transducer, a strain gauge, a pressure sensor, or the like. For example, a proximity sensor and/or force transducer may be located on each stop element opposed to a respective clamp, and/or each clamp may comprise a force transducer to determine the force being applied by that clamp.

The sensor arrays 550 located at the centre of each airbag assembly are then moved by actuating their respective pistons until the stop element 556 of each sensor array engages with a respective outer face of the skip. At this point, the respective vibration sensors and proximity sensors will also engage with the respective outer face of the skip. Any outward bowing in a wall of the skip is also eliminated to ensure each outer face is substantially planar prior to machining.

The centre airbag assembly 510 is then lifted and inserted into the skip by way of an airbag lifting device. As illustrated in Figure 1 1 , the airbag lifting device 1 100 includes a main frame 1 102 attachable to a crane or hoist by way of a lifting ring 1 104 coupled to the main frame by a pair of angled lifting bars 1106. A subframe 1 108 is mounted to the main frame which supports a plurality of sets of suction elements 1 110 for securing the airbag assembly 510 to the lifting device 1 100. A counterweight 1 1 12 is slidably mounted on the main frame to ensure the lifting operation is balanced.

The centre airbag 510 is then inflated to a first predetermined inflation pressure such that each side thereof engages with and urges the respective wall of the skip outwardly to ensure the same is substantially planar and not inwardly bowed. The proximity sensors of the sensor arrays 550 confirm this and also that that each vibration sensor is engaging its respective outer face of the skip. The centre airbag also supports the side walls of the skip and dampens/absorbs any vibrations thereof during machining. The outer airbags are then inflated to a first predetermined inflation pressure to clamp each wall of the skip between its respective outer air bag assembly and the inner airbag assembly. The skip is now fixed in its desired position for machining. The outer and inner airbags may now optionally be inflated to an increased second predetermined position, and all clamps may also optionally be clamped to an increased second predetermined clamping force. The skip is now ready to be machined by the precision machining apparatus.

If one or more of the proximity sensors located for example at each stop element confirm that the respective side or bottom of the skip are not in the desired location, the machining operations will not start.

A method of machining the skip according to certain embodiments of the present invention is illustrated in Figure 12. The skip 100 is unloaded from the skip fixture 400 by performing the steps of the loading process in reverse.

The method of locating and fixing a box 200 to be machined in the box fixture 600 according to certain embodiments of the present invention is the same as described above for the skip 100 using the same or similar lifting device 1000 as illustrated in Figure 10 and locating and clamping the box in the desired position with respect to the X, Y and Z axes ready for machining. Aptly, the box lifting device may be sized differently to the skip lifting device to ensure the lifting points on the inside of the respective container are proximal the corner regions thereof to prevent bending of the container wall during lifting. A method of machining the box according to certain embodiments of the present invention is illustrated in Figure 13. The box 200 is unloaded from the box fixture 600 by performing the steps of the loading process in reverse.

A method of mounting the skip lid and box lid vacuum plates on the main body of the lid fixture 800 according to certain embodiments of the present invention will now be described.

The first and second skip lid vacuum plates 820,822 and the first and second box lid vacuum plates 824,826 are each lifted onto the main body 802 of the lid fixture 800 by a vacuum plate lifting device 1400 as illustrated in Figure 14.

The vacuum plate lifting device 1400 includes an elongate main frame 1402 supporting an elongate electro-magnetic element 1404 from its underside. The main frame is coupled to a lifting ring 1406 by a pair of lifting bars 1408 for a hoist or crane to attach and lift the lifting device 1400. The electro-magnetic element 1404 is electrically coupled to the controller to allow the same to be selectively energised to securely attach to the upper edge region of one of the vacuum plates, and selectively deenergised to decouple from the vacuum plate. Each vacuum plate comprises a tapered recess along its upper edge to allow for efficient coupling of the lifting device 1400 thereto.

A method of fixing a skip lid 1 12 to be machined on the lid fixture 800 according to certain embodiments of the present invention will now be described.

The unmachined skip lid 1 12 is lying flat on a pallet. A lid lifting device 1500 as illustrated in Figures 15a and 15b is used to manoeuvre the skip lid 1 12 from the pallet and onto the first skip lid vacuum plate 820 mounted to the main body 802 of the lid fixture 800. The lid lifting device 1500 includes a rotatable frame 1502 rotatably coupled to a main frame 1504. The rotatable frame 1502 is selectively rotatable through ninety degrees relative to the main frame by a pair of actuators 1506, such as a pair of rams, between a horizontal position (Figure 15b) and a vertical position (Figure 15a). The rotatable frame 1502 supports a plurality of sets of suction elements 1508 for selectively securing to the skip lid 1 12. The main frame 1504 is coupled to a lifting ring 1510 by a pair of lifting bars 1512. A hoist, crane or the like couples to the lifting ring 1510 to thereby lift the lifting device and skip lid attached thereto.

The skip lid 1 12 is lifted from the pallet by the lifting device 1500 and swung into the vertical plane. The skip lid 1 12 is then located onto the first skip lid vacuum plate 820 for the first machining operation to be performed on the lid. The skip lid is located in the desired position by abutting the edges of the lid against the stop elements 844 of the first vacuum plate. A vacuum is applied within the recessed vacuum region 832 to secure the skip lid to the first vacuum plate. At least one proximity switch located on a lid engagement surface of the vacuum plate confirms the skip lid is located and secured correctly. Aptly, a proximity sensor/switch is located at each quadrant of the lid when mounted on the vacuum plate. The machining program to be executed by the machining apparatus based on the vacuum plate is determined by use of the identification element 900 on the vacuum plate. The first machining process is then performed.

The skip lid 1 12 is then removed from the first vacuum plate by the skip lid lifting device 1500 and placed vertically in a holding fixture (not shown). The skip lid lifting device 1500 is then manoeuvred to the other face of the skip lid and secured thereto by the suction elements. The skip lid 1 12 is then lifted from the holding fixture and located on the second skip lid vacuum plate 822 in the desired position and orientation using the locating pins 860. A vacuum is applied in the recessed vacuum region 852 to secure the skip lid to the second skip lid vacuum plate 822. The proximity switch confirms the skip lid is located and secured correctly. The machining program to be executed by the machining apparatus based on the vacuum plate is determined by use of the identification element on the vacuum plate. The second machining process is then performed.

Machining of the box lid 200 is performed in the same manner on the first and second box lid vacuum plates 824,826. A method of performing the two machining operations on the skip lid 1 12 and the box lid 212 according to certain embodiments of the present invention is illustrated in Figures 16a and 16b and 17a and 17b respectively.

A method of operating a precision machining apparatus, such as the Taurus 30™ vertical milling machine by Waldrich Coburg GmbH, configured to accept a palleted fixture assembly according to certain embodiments of the present invention, as illustrated for example in Figure 3, will now be described with reference to Figure 18. A first pallet 330 supporting a skip fixture 400, a box fixture 600, and a lid fixture 800, as illustrated for example in Figure 3, is loaded into the machine. The components to be machined, i.e. a skip, a box, first and second skip lids, and first and second box lids have been preloaded into or onto their respective fixtures. At operation 1 , the box is machined. At operation 2, the skip is machined. At operation 3, the first box lid is machined. At operation 4, the second box lid is machined. At operation 5, the first skip lid is machined. At operation 6, the second skip lid is machined. The first pallet is then unloaded from the machine, and the same operations are carried out in relation to a second pallet supporting further skip, box and lid fixtures according to certain embodiments of the present invention. In this manner, a batch of

components (skip, box and lids) can be machined on a single pallet and in a single pallet operation by a single precision machining apparatus.

Certain embodiments of the present invention therefore provide a machining fixture for supporting a sheet component, such as the wall of a box container, from both sides to thereby ensure precision machining of the component is achieved. A machining fixture according to certain embodiments of the present invention is configured to efficiently and consistently locate a box container having four walls and a base in a desired position, and to securely fix the box container in the desired position for precision machining thereof. The fixture comprises a clamping

arrangement for efficiently, consistently and securely locating the box container in the desired position before and during machining thereof. The fixture comprises an airbag arrangement for efficiently, consistently and securely supporting each wall and base of the box container from both sides and to absorb/prevent the base and walls vibrating during the machining process. One or more of airbag assemblies are configured to protect the airbag thereof from swarf and heat produced by the machining process. A machining fixture according to certain embodiments of the present invention is configured to efficiently and consistently locate a lid for a box container in a desired position, and to securely fix the lid in the desired position for precision machining thereof. A palletised set of machining fixtures are provided according to certain embodiments of the present invention which allows a batch of interoperable components to be machined on a single pallet and in a single pallet operation by a single precision machining apparatus. In accordance with certain embodiments of the present invention, a machine fixture is provided that ensures a desired surface finish on the engagement surfaces of the box container and lids is consistently achieved to high tolerance parameters, which in turn maximises tool life, reduces energy consumption and material/component waste, and optimises machining times.