The present invention relates to panels, particularly to panels for ceilings, and more particularly but not exclusively to integrated ceilings.

BACKGROUND OF THE INVENTION

In most enclosed spaces, the ceiling is utilised as a convenient location for providing many of the necessary amenities to ensure the enclosed space is a comfortable environment for its occupants.

It is well known in the art to locate lighting systems on or in the ceiling to provide effective lighting of the entirety of the enclosed space and to avoid the requirement for any lighting to require valuable floor space, which is in greater demand for other uses.

For the same reasons, heating or cooling systems to maintain a desirable temperature or environment in the enclosed space. More so than lighting, temperature control systems are often very bulky, particularly convective air systems, and are located above the ceiling surface. Chilled or warmed ceilings have been developed, whereby the ceiling surface itself is cooled or warmed to regulate the temperature of the ambient air beneath the ceiling.

Ceilings are often used as the location for systems for ambient noise reduction, which can be particularly important in an office or business environment where noise reduction is a regular concern.

The three systems for lighting, heating, and acoustic attenuation are conventionally entirely separate systems, which must be manufactured, installed, and maintained separately. Separate skilled personnel are required for the installation and maintenance of each system, resulting in inefficiency and increased costs.

Additionally, the separation of the various systems results in the requirement for a large amount of space above the ceiling surface to contain the necessary components. This is particularly important in buildings with multiple stories as the increased depth of each floor/ceiling section required to house the competing systems is multiplied numerous times, increasing the total height of the building and, therefore, the expense of construction. It is clear, then, that improvements in the field of ceilings are required to provide an improved ceiling arrangement to provide the necessary amenities.

STATEMENT OF INVENTION

In a first aspect, the present invention provides a panel, the panel being bounded by an edge enclosing a panel area, the panel comprising a plurality of light sources, a plurality of fluid conduits, and a plurality of fins, wherein the fluid conduits are each thermally coupled to at least one fin, each fin is arranged to diffuse light emitted by at least one light source and the fins and light sources are distributed throughout the panel area.

A panel according to the present invention offers improved integration of the multiple functions required of a ceiling in the modern indoor environment. A plurality of light sources provides lighting for the space below the panel. However, without diffusion, these light sources may produce extreme areas of dark and light below the panel. Traditionally, diffusion means are provided to scatter the light emitted by light sources in a ceiling to illuminate portions of the ceiling and to light the area below the ceiling more evenly, however, a large area of ceiling is taken up by such diffusion means, meaning less available ceiling area for other systems that must be located within the ceiling area. A panel according to the invention is not limited to use as a ceiling panel, but may be used in ceilings, sloping ceilings, walls, or even floors.

The effectiveness of a chilled or heated ceiling is a function of the area of thermal elements exposed to the air below the ceiling. However, the provision of lighting and light diffusion systems reduces the available area of ceiling for thermal transfer surfaces.

Therefore, in order to avoid the competition between the lighting and heating/cooling systems for ceiling area, the fins of the present invention are arranged to diffuse light emitted by at least one light source, and both the fins and the light sources are distributed throughout the panel area. By way of this arrangement, the surface area of the panel is utilised in a far more efficient manner as the fins dually perform both the diffusion and heat transfer with the air, which systems would conventionally be competing for the limited area available on the panel.

Preferably, the one or more fluid conduits are distributed throughout the panel area. A plurality of separate conduits may extend across the panel area. A single fluid conduit may be distributed across the entire panel area, for example in a spiral, zig-zag, or serpentine arrangement. A plurality of fluid conduits, each of which extends across a portion of the panel area, could in combination distribute fluid conduits throughout the panel area when connected in series or in parallel.

Preferably, the fins form a discontinuous layer. By providing discontinuity in the fin layer, air in the space below the panel is exposed to all sides of the fin, which in most cases at least doubles the effective surface area for thermal transfer. Furthermore, a continuous layer of fins would reflect the majority of sound below the panel back towards the room, rather than allowing sound to be dissipated above the panel.

The discontinuity of the fin layer also allows the light emitting means to be located in a greater range of positions relative to the fins. A continuous layer would prevent the permeation of light, and therefore all light sources would necessarily be located below the fins. Advantageously, the discontinuous layer of fins allows the light to be diffused by more of the fins' area and therefore provides a more effective diffusion effect.

Preferably, each of the fins is thermally coupled to at least one fluid conduit. In this way, all of the fins can be utilised as a heat transfer element and provide a greatly increased effective surface area for heat transfer with air below the pane!

Advantageously, the light sources may be distributed within the panel area. The even distribution of the light sources can prevent light or dark spots on the panel, or in the room below the panel.

Also advantageously, the fluid conduits may be arranged within both the peripheral and central areas. Providing evenly distributed fluid conduits avoids hot and cold spots amongst the distributed fins. Extremes of cold or heat can cause condensation or overheating issues, and therefore providing an even spread of fluid conduits thermally connected to the fins can prevent localised extremes of temperature in the panel.

Preferably, the fins are distributed within the peripheral and central areas. Therefore, the light diffusion and heat transfer can take place across substantially all of the panel area.

Advantageously, the light sources can be LED light sources. The cooling power generated by the fins may be compromised if it must also remove excessive heat produced by the light sources. LED light sources are increasingly efficient over conventional light sources and therefore, if these low heat light sources are utilised, the cooling that can be applied to the ambient air by the fins is increased. LED light sources have improved performance and an extended life if their junction temperature is kept low. Integrating lighting and cooling systems in this way can increase the life expectancy, efficiency, brightness, and overall efficacy of the LED light sources.

Preferably, the panel may further comprise acoustic damping means. If the three key systems of temperature control, illumination, and acoustic damping are integrated into the same panel, then complex and time-consuming installation of each system separately is avoided. Furthermore, if located within the same panel, each of these systems can be tailored to compliment the function of the other two systems. For example, the shape of the fins of the panel can be designed such that sound is preferably directed towards the acoustic damping means, rather than reflected back into the room below the panel. Advantageously, the acoustic damping means may also be arranged above said fins. Therefore, the damping means will not obscure the light sources and any diffused light, and will not inhibit airflow around the fins, which is vital for their cooling or heating function. Preferably, the acoustic damping means may comprise a passive acoustic absorbing material, for example a panel of such material arranged above the lights and fins.

Advantageously, one or more of the fins may comprise one or more perforations. When utilised with an acoustic damping material, the fins may tend to reflect sound back into the room below the panel, which can increase noise rather than reduce it. If perforations are provided in the fins, then sound may more easily permeate the layer of fins and be absorbed or dampened by the acoustic damping means. Furthermore, perforations in the fins may serve to increase the surface area of the fins, provide better air circulation around the fins, and/or provide increased diffusion of light hitting the fins.

Preferably, when the panel is in use, a substantial temperature gradient may be created between one or more of the fins and ambient air around the fins. A substantial driving temperature gradient between the fins will serve to heat or cool the surrounding air.

Advantageously, the total surface area of the fins may be greater than the projected area of the panel. As the fins define the total surface area for heat transfer with the ambient air, it is advantageous to provide more surface area than would be provided by a conventional flat chilled ceiling.

Preferably, the panel may be a modular panel. Modular systems are constructed in standardized units or with standardised dimensions, which provide flexibility and variety in arrangement, design, and use. Therefore, similar panels can be used to create a variety of differently shaped or sized ceilings or walls without the requirement for bespoke components. Furthermore, the panels may be arranged to give a seamless appearance. The edge of one panel may arrange with the edge of an adjacent panel such that the pattern of fins on each panel is repeated across a join or abutment of panels without a break or interruption, thereby giving the illusion of a continuous ceiling or wall. Preferably, two or more panels may be arranged with adjacent to one another such that the two or more panels define a substantially continuous surface. Preferably, the fins on each panel may be arranged in a regular or repeated pattern.

Advantageously, the fins may be non-planar. A non-planar fin can provide an increased surface area for heat transfer within its projected surface area than the equivalent planar fin. Furthermore, a non-planar fin can scatter light from the light sources in a greater variety of directions, providing more even illumination.

Preferably, one or more of the fins may comprises a reflector portion arranged such that a portion of light emitted by one or more of said light sources is reflected at least partially towards said panel. Reflecting light back towards the panel can illuminate the panel more evenly and thereby avoid unattractive or distracting contrasts between light and dark spots on the panel. For example, a light source may be arranged to emit light downwards, away from the panel. The reflector portion of a fin may be arranged to reflect that light upwards, back towards the panel, and onto a diffusion portion of the fin such that light from the light source is diffused from a larger area of the fin that might otherwise be achieved by seeking only to directly illuminate diffusion areas of the fins.

Advantageously, the panel may further comprise one or more hangers, wherein the mechanical support of the panel is provided substantially by the hangers. By providing mechanical support for the panel, and therefore the systems integrated into the panel, each system does not require separate attachment and fitting. Furthermore, the entire panel can be easily removed for servicing or decommissioning by removing a small number of convenient connections, rather than the removal of the cooling, lighting, or acoustic damping systems separately.

Preferably, each fluid conduit may be thermally coupled to two or more fins. A reduced number of fluid conduits is required if each fluid conduit is thermally coupled to more than one fin. Furthermore, the temperature of multiple fins can be controlled simultaneously by changing the temperature of a single fluid conduit, which provides more efficient and simple control of an even temperature across all or a selection of the fins.

Each light source may illuminate at least two fins. Therefore, the light from each light source can be diffused by a greater number of fins, providing more distributed diffusion of light. The greater the number of fins illuminated the more diffusion of the light takes place.

Advantageously, the panel may further comprise one or more thermally conductive support members. The support members may mechanically support one or more of the fluid conduits and one or more of said fins and may thermally couple one or more of the fluid conduits to one or more of the fins. A multi-purpose support member such as this can provide both thermal connection and mechanical attachment between the fins and the fluid conduits. Both mechanical support and thermal connection require an area of attachment of the components to be attached, so the effectiveness of both systems can be increased by providing both functions in a single component.

The panel area may comprise a peripheral area surrounding a central area, the peripheral area extending from the edge of the panel area around the panel. Preferably, the panel area is bounded by four edges, comprising a pair of opposed longitudinal edges and a pair of opposed lateral edges. The peripheral area may include areas adjacent each of the edges. Preferably, the peripheral area may comprise at least 20% of the panel area. More preferably, the peripheral area comprises at least 40% of the panel area or, even more preferably, comprises at least 50% of the panel area.

Preferably, substantially all of the panel area is illuminated. Illumination of the entire panel area reduces the tendency for dark and light spots.

All of the fins on the panel may be identical in shape, or a selection of the fins may have an identical shape. In this manner, the fins may be mass-produced or otherwise manufactured in bulk, which may provide cheaper and simpler manufacturing and easy replacement of fins.

Advantageously, the fins and support members may be constructed of materials having high thermal conductivity, for example metals. Preferably, the fins and/or the support members are made from aluminium, which is both lightweight and has a high thermal conductivity. Other parts of the panel, for example the fluid conduits and the light battens may also be manufactured from metals, or preferably aluminium. The fluid conduits may be clipped in place on the support members or directly to the fins for easy fitting and replacement of faulty conduits. Alternatively, the fluid conduits may be formed as an integral part of the panel, or formed within the fins, support members, or light battens.

The fluid conduits may be linear and arranged in series or parallel between the inlet and outlet. The fluid conduits may be shaped in a serpentine fashion. The serpentine arrangement may be formed of a single piece, or alternatively a combination of multiple pieces of linear and curved pipework joined together in parallel or in series. If the fluid conduits are arranged in parallel, then a reduced number of inlets and outlets may be required for a set number of fluid conduits. For example, a plurality of parallel fluid conduits could be fed fluid from a single shared inlet and expel fluid at a single shared outlet.

The panel may further comprise a plenum chamber at the inlet, outlet, or both to provide a pressure differential through the fluid conduits and thereby promote flow of fluid.

The fluid to be flowed through the fluid conduits may be any suitable fluid. Preferably, the fluid may comprise water or oil. The fluid may further comprise additives with desirable properties such as anti-corrosion and anti-freeze.

It has been contemplated that the fins of the present invention could be elongate strips of thermally conductive material. The elongated strips may be secured within the panel at either end. The elongated strips may be shaped to form a helix or may alternatively be flat or serpentine, or otherwise formed about a central axis. Two or more helical strips may be arranged about a common axis to form a multiple helix, such as a double or triple helix. Each helical strip may have its own fluid conduit, which may further extend substantially along the length of the strip. Each strip may further comprise one or more of the light sources. The light sources on the strip may be arranged on an inner surface of the helical strip, such that when two or more helical strips are arranged about a common axis to form a multiple helix, the light sources on each strip illuminate the one or more other strips in the multiple helix. One or more multiple helixes formed of multiple strips may be arranged in the panel. A number of multiple helixes or strips may be distributed throughout the panel area, for example a number of strips or helixes may be arranged adjacent one another in a layer.

As before, the helixes provide a discontinuous covering to the panel allowing sound to reach any acoustic damping material provided above the panel. Further advantageous features may be described in the appended dependent claims. DETAILED DESCRIPTION OF THE EMBODIMENT

A better understanding of the present invention will be obtained from the following detailed description. The description is given by way of example only and makes reference to the accompanying drawings, in which:

Figure 1 is a bottom view of a ceiling panel according to the present invention; and

Figure 2 shows a top view of the technical layers of the ceiling panel of Figure 1 ;

Figure 3 shows a cross section of the ceiling panel of Figure 1 on the line A-A;

Figure 4 illustrates a cross section of the ceiling panel of Figure 1 on the line B-B;

A ceiling panel 10 according to the present invention is shown in Fig 1. Fig 1 shows a bottom view of the panel in which number of fins 12 and LED light sources 14 are visible.

The LEDs 14 are set out in a repeating pattern with a central LED 14 and 6 LEDs 14 arranged around it at the vertices of a hexagon centred on the central light. Each LED 14 at a vertex forms a central LED 14for another hexagon.

It will be understood that other shapes of fin or patterns could be used; however, the repeated hexagonal arrangement provides that each pair of fins 12 must occupy 60° of the 360° around each LED 14. Therefore, manufacture of the fins is made easier as each fin may be identical. This arrangement also provides a good compromise between the depth of the fin and the difficulty of folding each fin to a small angle.

Each fin 12 is constructed from a single sheet of aluminium having a thickness of around 1 mm. The shape and construction of each of the fins 12 is shown in more detail and described here with reference to Figs 3 and 4.

Each fin comprises a flange 120 that is substantially planar and serves as the attachment point by which each fin 12 is secured to the panel 10. Said attachment point provides the thermal connection between the fluid conduits 16 and the fins 12. During manufacture, the flange 120 is bent away from the fin sheet fin 12 to form a fin portion 122. Each fin 12 further comprises a plurality of slits 124, two cutaways 126, and two reflector portions 128. Features of each fin 12 are shown in detail in Fig 4, where it can be seen that the reflector portion is folded underneath the fin portion 122 to provide a surface substantially parallel to the flange 120 of the fin 12. The cutaways 126 are located at either end of the fin portion 122 and define the reflector portions 128 below. The reflector portions 128 at either end of the fin portion 122 are folded at an angle underneath the rest of the fin portion 122 such that the inner surface of the reflector portion 128 faces toward the flange 120. The slits 124 are punched out of the fin portion 122 on the triangular face of the fin portion defined by the folds of the reflector portions 128. These slits are provided to give acoustic transparency through the fins 12, so that sound can permeate the layer of fins 12 more easily. The slits 124 also allow better airflow around the fins 12, which can provide more efficient heat transfer. The slits can also provide more effective diffusion of light as more reflective surfaces are created and may increase the surface area of the fin 12 slightly.

Returning to Fig 1 , away from the edge 102 of the panel 10, the fins 12 are arranged in pairs that are secured adjacent one another along the fold between the flange 120 and the fin portion 122 to form a petal 104. Along each edge 102 of the panel 10, the fins are arranged such that the fold between the flange 120 and the fin portion 122 meets the edge 102 of the panel. Therefore, when two panels 10 are arranged with abutting edges 102, the single fins 12 along the adjacent edges 102 align along the fold to form a petal similar to the other petals 104 on the remainder of the panels 10. This arrangement provides a 'seamless' effect when two or more panels are installed adjacent one another. To the casual observer, this arrangement gives the illusion that the multiple panels are in fact a single continuous ceiling. When arranged adjacent another panel 10, the lights at the edge 104 of one or both of the panels' edge illuminate fins on the adjacent panel.

The panel 10 is arranged with a group of six petals 104 around each LED 14. Furthermore, each petal 104 has a light at each of its ends. The angle of each end portion 128 of each fin 12 and between adjacent edges 102 of the panel 10 are such that the petals 104 are congruous and the pattern can be repeated across the entire bottom surface of the panel 10 with single fins 12 arranged at each edge 102 as shown in Fig 1.

With reference to Fig 2, the technical arrangement of the panel 10 will be described in more detail. Fig 2 shows the technical layers of the panel 10 from a top view. The flanges 120 of the fins 12 in each petal 104 are shown on the bottom layer. The flanges 120 are connected to a layer of support members 22 (not shown in Fig 2). Substantially all of each flange 120 is in contact with one or more of the support members 22 to provide maximum area of contact between the flange and the support members 22. The support members 22 are extruded aluminium section, which have mating portions 220 on either edge (see Fig 4), which provide a sliding connection between adjacent members 22. When a number of support members 22 are connected adjacent one another, a substantially continuous layer is formed.

Arranged above the support members 22 are a plurality of fluid conduits 16. The conduits 16 each have an inlet 162 and an outlet 164. Each conduit 16 is a copper pipe. Each conduit 16 is arranged to have sections 164 extending linearly in a first direction adjacent the layer of support members 22, then return in a second direction substantially opposite and parallel to the first direction in a repeated pattern with regular spacing between each linear section 164 of the conduit 16, forming a serpentine path. Each of the conduits 16 is arranged in a track 224 in the support members 22 to increase the contact area between the conduit 16 and the support members 22. In the panel 10, two fluid conduits 16 are provided, each being distributed across half of the panel, which in combination distribute fluid conduits across the entire panel area.

Above the layer of support members 22, a number of light battens 18 are arranged with even spacing. Along each of these battens 18, LEDs 14 are located at regular intervals. Apertures 226 in the support members 22 locate the LEDs 14 such that they are arranged at the meeting point of the ends of each group of six petals 104 as shown in Figure 1. Power is provided to each LED 14 along its corresponding light batten 18, which in turn is fed by a single electrical connection 24. The electrical connection 24 is connected to the mains and provides the electrical power for all of the LEDs 14 in the panel 10.

Arranged above the light battens 18 are six acoustic damping pads 20. The pads 20 are constructed from rock wool, dense foam, or other acoustic damping material that absorbs sound in a passive manner. At the edges of each pad 20, the support member 22 below has a protruding bracket 228 as shown in Figure 4 that supports the pad 20 at its edges. Furthermore, bolts 202 are arranged at even spacings across each pad, which are mated with corresponding threads 204 in the support members 22 below to provide further support for each pad 20. Although the panel as illustrated has gaps between the pads 20, it will be understood that specially shaped pads could be used to fill the edge gaps, or cover substantially the entire upper surface of the panel.

The brackets 228 also provide a connection to the hanger arrangement 26. The brackets 228 are bolted to a lower hanger 262 that provides multiple connection points for the adjacent brackets 228. The lower hanger 262 is further bolted to an upright hanger 264, which provides some vertical spacing from the upper surface of the pads 20. The top of the upright hanger 264 is bolted to the ceiling shaft 266, which is connected to the ceiling at the location of the panel. The shafts 266 support the entire panel 10, via the hanger arrangement 26. A number of hangar arrangements 26 are provided on each panel 10, which will depend upon the weight of the panel 10 and the load bearing capacity of the shafts 266.

Now, the operation of the panel will be described in more detail with reference to all of the Figures, but in particular to Figs 3 and 4.

In use, a fluid is flowed along the fluid conduits 16 from the inlet 162 to the outlet 164. A push-fit connection is provided at the inlet 162 and the outlet 164 to provide simple installation without the requirement for specially trained personnel. The temperature of the fluid is tailored to the required cooling or heating power required from the panel. For brevity, the panel 10 will be described henceforth as providing a cooling function, but it will be understood that the panel 10 could perform a heating function if a fluid at a temperature above the ambient temperature of flowed through the fluid conduits 16.

The fluid flowed through the panel 10 is at a substantially lower temperature than the ambient temperature of the air around the panel 10. Therefore, the fluid conduits 16, which are constructed of copper, have a substantially similar temperature to the fluid therein. The support members 22 are constructed from extruded aluminium, which has a high thermal conductivity, and have a large area of contact with the fluid conduits 16 via the tracks 224. As a result, the support members 22 are also cooled to a substantially similar temperature to the fluid in the conduits 16.

As described, the flanges 120 of the fins 12 are connected with substantially the entire surface of the flange in contact with one or more support members 22. Conduction of heat between the cooled support members and the fin 12 through the flange 120 results in cooling of the fins 12, which are chilled to a temperature around 5-6 degrees below the temperature of the ambient air.

It will be understood that a reduction or increase of the temperature of the fluid in the conduits 16 will result in a corresponding increase or decrease of the temperature gradient between the fins 2 and the ambient air. As the air around the fins 12 meets the chilled fin portions 122 or the chilled support members 22, heat transfer takes place and the air is cooled, predominantly by convention and conduction. As the fluid conduits 16 have a constant flow of chilled fluid, the fluid conduits provide a heat sink, which removes heat from the air via the fins 12 and the support members 22. As the air around the panel 10 is cooled, it sinks and is replaced by warmer air rising below the panel 10, which is then cooled. This convective current is self-maintained so long as chilled fluid is flowed through the fluid conduits 16.

As all of the fins 12 are thermally coupled to the chilled support members 22, substantially all of the fins 12 are cooled, and a large effective area is provided for heat transfer with the air. Traditional chilled ceilings are predominantly flat, so the panel 10 represents a significant improvement in the area for heat transfer.

The illumination of the panel will now be explained with reference to Figs 1 and 3. Fig 3 illustrates an exemplary portion of the cross-section of the panel 10 along the line A-A, which shows two fins 12 and three LEDs 14 arranged at the ends of the fins 12.

As previously described with reference to Fig 1 , each pair of fins 12 form a petal 104. Six petals 104 are arranged in a star formation around each LED 14, such that that every petal 104 has an LED 14 adjacent each end.

Each LED 14 has a beam angle β. The beam angle is the angle defined between a line perpendicular to the LED 14 and the extent of the light cone emitted by the LED 14, as shown in Fig 3. Each LED will have a different beam angle, so it will be understood that the beam angle and any associated angles may be altered without changing the principles of the invention.

As shown in Fig 3, a central portion of the light cone of the LED 14, which passes between the tips of the reflector portions 128, will be unaffected by the fins 12 and will provide direct illumination to the area below the panel 10. However, it is undesirable to illuminate the area below the panel 10 completely by direct illumination from the LEDs 14. Lighting in this manner can create light and dark areas below the panel 10, as the light from the LEDs 14 would not be effectively diffused.

In order to diffuse the light from the LED 14 more effectively, the reflector portions 128 of the fins 12 protrude into the light cone of the LED 14. Above the reflector portion 128, the cutaway 126 is carefully shaped to allow the maximum amount of light to reach the reflector portion with the minimum loss of surface area of the fin portion 122. To achieve this, the top edge of the cutaway 126 is cut into the fin portion at substantially the same angle as the beam angle β.

As shown in Fig 3 where a petal 104 is shown in cross-section, the reflector portions 128 and the cutaways 126 of each pair of fins 12 are arranged adjacent one-another to define an aperture 1210. As six petals 104 are arranged around each LED 14, the majority of the light produced by each LED is either projected directly below the panel, or enters the petals 104 arranged around it through the apertures 1210.

Returning to Fig 4 once the light has entered the petal 104 through the aperture 1210, it reaches the upturned inner surface 130 of the reflector portions 128. The shape of each reflector portion 128 provides a range of angles at which the light entering the petal 104 can be reflected back towards the panel 10 and the fin portion 122. This causes scattering or diffusion of the reflected light, which is then reflected again by the fin portion 122 in a direction below the panel 10. The folds and multi-faceted nature of each fin 12 provides very effective diffusion of the light entering the apertures 1210.

Furthermore, the slits 124 also increase the scattering of light. The diffusion of the LED 14 light provides multiple advantages. Firstly, the light is scattered before being reflected into the area below the panel 10, which provides more even illumination of the entire area below the panel and helps to prevent the appearance of dark and light spots. Secondly, the reflected light also illuminates each of the fins 12, thereby providing a more even illumination of the entire panel 10, which is more aesthetically pleasing and less distracting to the eye. Thirdly, the use of a portion of the fins 10 to reflect the light removes the need to provide separate light diffusers as would present in a conventional ceiling, thereby increasing the available area for heat transfer through the fins 12.

The present invention is not limited to the specific embodiments described herein. Alternative arrangements and suitable materials will be apparent to a reader skilled in the art.