Patent Description:
Typically, wind turbine blades are manufactured in two halves, or shells, which are adhesively bonded together along the leading and trailing edges of the blade. A shear web structure is provided between the shell halves.

Structural adhesive is used to bond the inner surfaces of the shells to the shear web structure, and to bond the edges of the shells together. It will be appreciated that the adhesive bonds provide critical connections between the various components of the blade, and that the bonds must therefore have extremely high integrity to withstand the high forces and fatigue loads experienced in operation. To this end, the process of creating adhesive bonds during production of wind turbine blades must be highly repeatable and robust.

It is known to apply adhesive to a surface of a wind turbine blade component using an adhesive deposition tool. Adhesive is supplied to the adhesive deposition tool at a constant flow rate and an operator moves the tool along an application surface of a first component, for example the inner surface of a blade shell, to deposit a continuous elongate bead of adhesive onto the surface. A second component, for example a web foot, to be adhered to the first component, is then placed on top of the adhesive bead and the assembly is cured to form an adhesive bond.

It has been found in practice that known adhesive deposition tools can produce adhesive beads having inconsistent cross-sections and thicknesses. Such inconsistencies negatively affect the repeatability and consistency of the bonding process.

It is against this background that the present invention has been developed.

<CIT> describes a sealant application nozzle and a sealant application method. The sealant is applied to stepped portions created by the bonding of two members to each other. <CIT> describes a dispenser for applying a structural adhesive to a wind turbine blade structure.

According to an aspect of the invention, there is provided an adhesive deposition tool according to claim <NUM>.

Preferably, the top portion comprises a first baffle downwardly pitched towards the front of the tool.

In addition, or alternative to the first baffle of the top portion, at least one of the two side portions may comprise a baffle inwardly pitched towards the front of the tool.

Preferably, the side portions forwardly extend ahead of the front end of the chamber.

The top portion comprises a baffle downwardly pitched towards the rear of the tool so as to decrease the height of the chamber towards the rear end of the chamber. This baffle of the top portion is referred to herein as the "second baffle".

Preferably, the height of the chamber at the front and rear ends of the chamber is substantially equal.

Preferably, the cross-sectional areas of the front and rear ends of the chamber are substantially equal.

Alternatively, the cross-sectional area of the front end of the chamber is smaller than the cross-sectional area of the rear end of the chamber.

Alternatively, the cross-sectional area of the front end of the chamber is greater than the cross-sectional area of the rear end of the chamber.

Preferably, the second baffle is configured such that the height of the chamber continuously decreases towards the rear end of the chamber.

Preferably, the top portion and/or the at least one side portion is configured such that the height and/or the width of the chamber continuously decreases towards the front end of the chamber.

Preferably, the top portion and/or the at least one side portion is configured such that the height and/or the width of the chamber increases and subsequently decreases towards the front end of the chamber.

Preferably, the tool further comprises a profiler having a cut-out profile portion.

Preferably, the cut-out profile portion of the profiler defines the rear end of the chamber.

Preferably, the overall length of the tool is greater than <NUM>.

Preferably, the tool further comprises an elongate handle defining the supply channel, wherein the elongate handle is configured to rearwardly extend away from the front end of the chamber.

One or more examples of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:.

In the drawings, like features are denoted by like reference signs.

The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and examples in which the invention may be practiced. These examples are described in sufficient detail to enable those skilled in the art to practice the invention. Other examples may be utilised, and structural changes may be made without departing from the scope of the invention as defined in the appended claims. Moreover, references in the following description to "upper", "lower" and any other terms having an implied orientation are not intended to be limiting, and refer only to the orientation of the features as shown in the accompanying drawings.

<FIG> illustrates a component of a wind turbine blade, in the form of a wind turbine blade half shell <NUM> (hereinafter, "the half shell <NUM>"), supported in a blade mould <NUM>. The half shell <NUM> may form a windward half or a leeward half of a wind turbine blade. An operator <NUM> is shown depositing a bead of structural adhesive <NUM> (hereinafter, "the bead of adhesive <NUM>") on an application surface <NUM> of the half shell <NUM> using a known adhesive deposition tool <NUM>. In this example, the application surface <NUM> forms part of an inner surface <NUM> of the half shell <NUM> and the bead of adhesive <NUM> is used to bond a shear web (not shown) to the inner surface <NUM>.

The adhesive deposition tool <NUM> comprises an elongate handle <NUM>, to which a supply hose <NUM> is connected for delivering a continuous supply of structural adhesive to the tool <NUM>. The elongate handle <NUM> is used by the operator <NUM> to push the tool <NUM> along the application surface <NUM> of the half shell <NUM> in a spanwise direction (indicated by arrow S). That is to say, the tool <NUM> is pushed along the length of the half shell <NUM>. As the tool <NUM> is moved, the bead of adhesive <NUM> is dispensed in its wake.

The tool <NUM> is moved over the application surface <NUM> along a predefined adhesive deposition path <NUM>, which is indicated on the inner surface <NUM> of the half shell <NUM>. The adhesive deposition path <NUM> indicates the precise location at which the structural adhesive should be deposited in accordance with the design specification of the wind turbine blade. The adhesive deposition path <NUM> may be indicated on the inner surface <NUM> of the half shell <NUM> by means of laser projection. Alternatively, or additionally, the adhesive deposition path <NUM> may be physically marked on the inner surface <NUM> of the half shell <NUM> using a pen or pencil, or the like. The adhesive deposition path <NUM> therefore indicates a predefined path along which the tool <NUM> must be moved. A physical guide (not shown), attached to the inner surface <NUM> of the half shell <NUM> adjacent the adhesive deposition path <NUM>, might also be used for guiding the tool <NUM> along the adhesive deposition path <NUM>. The physical guide is arranged parallel to the adhesive deposition path <NUM> and is spaced apart therefrom by a predetermined distance. The physical guide extends longitudinally in the spanwise direction along the whole or part of the length of the half shell <NUM>.

With reference to <FIG>, the tool <NUM> comprises a top portion <NUM>, two parallel side portions <NUM>, the elongate handle <NUM>, located substantially on the longitudinal axis of the tool <NUM>, and an adhesive profiler <NUM>. The adhesive profiler <NUM> is located at the rear end <NUM> of the tool <NUM> and comprises a rectilinear cur-out profile <NUM>, generally in the shape of a house, for profiling the structural adhesive as it is deposited from the tool <NUM> onto the application surface <NUM>. The front end <NUM> of the tool <NUM> is open. That is, the tool <NUM> does not include a feature to restrict the flow of structural adhesive from its front end <NUM>.

Turning to <FIG>, the handle <NUM> defines a supply channel <NUM> for supplying structural adhesive <NUM> (hereinafter, "the adhesive <NUM>") to a chamber <NUM> that is defined within the volume of the tool <NUM> by the interior surfaces of the top and side portions <NUM>, <NUM>, and the adhesive profiler <NUM>. The top portion <NUM> is configured to slope upwardly from the rear to the front end <NUM>, <NUM> of the tool <NUM>, progressively increasing the height, and so the cross-sectional area, of the chamber <NUM> towards the front end <NUM> of the tool <NUM>. In use, the adhesive <NUM> is supplied to the chamber <NUM> through the supply hose <NUM> and then the supply channel <NUM>. The adhesive <NUM> is allowed to largely fill the chamber <NUM> before the tool <NUM> is moved by the operator <NUM> along the adhesive deposition path <NUM> in the direction S. As the tool <NUM> is moved, the adhesive <NUM> exits the tool <NUM> through the cut-out profile <NUM> of the adhesive profiler <NUM> to form the bead of adhesive <NUM> on the application surface <NUM>. Due to the high viscosity of the adhesive <NUM> at typical application temperatures of around <NUM> to around <NUM>, the bead of adhesive <NUM> generally retains the shape of the cut-out profile <NUM> of the adhesive profiler <NUM> after it has been deposited on the application surface <NUM>.

Due to profile of the top portion <NUM>, configured to slope upwardly from the rear to the front end <NUM>, <NUM> of the tool <NUM>, a large proportion of the adhesive <NUM> entering the chamber <NUM> from the supply channel <NUM> tends firstly to flow towards the front end <NUM> of the tool <NUM>, following the path of least resistance. This flow pattern causes the adhesive <NUM> to form a rounded nose <NUM> at the front end <NUM> of tool <NUM>, flowing downwards from the top portion <NUM> of the tool <NUM> towards the application surface <NUM>. This establishes a number of drawbacks with using the known tool <NUM>. For example, during the application of the adhesive <NUM>, it is desirable that the operator <NUM> controls the movement of the tool <NUM> so as to apply the adhesive <NUM> to the application surface <NUM> at approximately the same rate as it is supplied to the tool <NUM>. If the application rate of the adhesive <NUM> is below the supply rate, the rounded nose <NUM> of the adhesive <NUM> extends further forward of the front end <NUM> of the tool <NUM>. This can cause some of the adhesive <NUM>, forming the rounded nose <NUM>, to work its way underneath the side portions <NUM>, <NUM> as the tool <NUM> is moved along the adhesive deposition path <NUM>. That is, some of the adhesive <NUM> gets drawn in between the bottom surfaces of the side portions <NUM>, <NUM> and the application surface <NUM> as the tool <NUM> is moved along the adhesive deposition path <NUM>. This creates strips of adhesive <NUM> either side of the bead of adhesive <NUM>, which need to be removed before the shear web can be bonded to the inner surface <NUM> of the half shell <NUM>, adding to the workload of the operator <NUM> and generating wasted adhesive <NUM>.

Another drawback with using the known tool <NUM> is the creation of an inconsistent connection between the bead of adhesive <NUM> and the application surface <NUM> as the tool <NUM> is moved along the adhesive deposition path <NUM>. With reference to <FIG>, when the tool <NUM> is stationary or moved so as to apply the adhesive <NUM> at a low application rate, some of the adhesive <NUM> entering the chamber <NUM> is pushed downward, by the continuous flow of the adhesive <NUM>, onto an area of the application surface <NUM> approximately below the supply channel <NUM> and extending rearwardly therefrom. The rest of the adhesive <NUM> generally flows forward to create the rounded nose <NUM>, in which the adhesive <NUM> flows downward from the top portion <NUM> of the tool <NUM> to sit on the application surface <NUM>. That is, the adhesive <NUM> at the base of the rounded nose <NUM> is not positively forced into but rests on the application surface <NUM>, establishing a poorer connection therebetween when compared to the situation in which the adhesive <NUM> is pushed onto the application surface <NUM>. This can lead to "dead areas" within the chamber <NUM>, generally indicated by <NUM>, in which the adhesive <NUM> continuously circulates without ever being laid down on the application surface <NUM>. As the application rate increases, some of the adhesive <NUM> at the base of the rounded nose <NUM> is drawn under the tool <NUM>, as shown in <FIG>, to form part of the bead of adhesive <NUM>. Nevertheless, the difference in the pressures under which the adhesive <NUM> is initially laid down on the application surface <NUM> between the front and rear sections of the tool <NUM> can lead to inconsistencies in the profile of the bead of adhesive <NUM>. In particular, with reference to <FIG>, in sections where the connection between the adhesive <NUM> and the application surface <NUM> is poorer, the bead of adhesive <NUM> is pulled and stretched as it is dispensed from the tool <NUM>. This causes its width to narrow, as generally indicated by <NUM>, relative to those sections of the bead of adhesive <NUM> in which the connection between the adhesive <NUM> and the application surface <NUM> is comparatively better. The operator <NUM> is therefore required to correct these inconsistences in the profile once the bead of adhesive <NUM> has been laid down on the application surface <NUM> to ensure a reliable bonding of the shear web.

The invention seeks to overcome or substantially mitigate at least some of the drawbacks associated with the known tool <NUM>.

In general terms, the adhesive deposition tools of the present disclosure are configured such that the cross-sectional area of the chamber, defined by a substantially vertical plane extending between lower and upper boundaries of the chamber, decreases towards a front region of the chamber. This is advantageous as it increases the pressure exerted by the adhesive on the boundaries of the chamber in that region of the chamber, comparative with the known tool, and, in doing so, improves the initial contact established between the adhesive and the application surface.

<FIG> shows an example of an adhesive deposition tool <NUM> comprising a top portion <NUM>, two side portions <NUM> and a supply channel <NUM>. An inner surface <NUM> of the top portion <NUM> defines the upper boundary of an open-ended chamber <NUM> within the volume of the tool <NUM>, and inner surfaces <NUM> of the two side portions <NUM> respectively define side boundaries of the chamber <NUM>. The chamber <NUM> comprises a front end <NUM> and a rear end <NUM>, and, in use, the application surface <NUM>, onto which structural adhesive is deposited from the tool <NUM>, defines the lower boundary of the chamber <NUM>.

With reference to <FIG>, the tool <NUM> is operated in substantially the same way as the known tool <NUM>. That is, adhesive <NUM> is supplied to the chamber <NUM> through the supply channel <NUM>. The adhesive may be allowed to largely fill the chamber <NUM> before the tool <NUM> is moved by the operator <NUM> along the adhesive deposition path <NUM> in the direction S. As the tool <NUM> is moved, the adhesive <NUM> exits the tool <NUM> from the rear end <NUM> of the chamber <NUM> to form a bead of adhesive <NUM> on the application surface <NUM>. The supply channel <NUM> may be defined by an elongate handle <NUM>. The elongate handle <NUM> may be configured to extend rearwardly away from a front end <NUM> of the tool <NUM>. The operator <NUM> may use the elongate handle <NUM> to move to tool <NUM> along the adhesive deposition path <NUM>.

The top portion <NUM> is configured such that the height of the chamber <NUM> decreases towards the front end <NUM> of the chamber <NUM>, resulting in a progressive decrease in the cross-sectional area of the chamber <NUM> towards its front end <NUM>. Specifically, the top portion <NUM> comprises a first baffle <NUM> downwardly pitched towards the front end <NUM> of the tool <NUM>. This arrangement reduces the volume of chamber <NUM> towards its front end <NUM> This may restrict the flow of the adhesive <NUM> towards the front end <NUM>, preventing the formation of a large rounded nose of adhesive. The arrangement of the first baffle <NUM> may increase the pressure exerted by the adhesive <NUM> on the boundaries of the chamber <NUM> in that region of the chamber <NUM> (when compared with the known tool <NUM>). This pressure increase pushes the adhesive <NUM> onto the application surface <NUM> below the front end <NUM> of the chamber <NUM>, improving the connection that is initially established therebetween. The decrease in the cross-sectional area of the chamber <NUM> towards the front end <NUM> may also increase the uniformity of the pressure along the chamber <NUM> under which the adhesive <NUM> is initially laid down on the application surface <NUM> before it exits from the rear end <NUM> of the chamber <NUM> to form the bead of adhesive <NUM>. The improvement in the initial contact formed between the adhesive <NUM> and the application surface <NUM> eliminates inconsistences in the profile of the bead of adhesive <NUM> brought about by the pulling or stretching of the adhesive <NUM> as it exits the tool <NUM>.

The top portion <NUM> comprises a second baffle <NUM>. The second baffle <NUM> is downwardly pitched towards a rear end <NUM> of the tool <NUM> so as to decrease the height of the chamber <NUM> towards its rear end <NUM>. Downwardly pitching the second baffle <NUM> towards the rear end <NUM> of the tool <NUM> may progressively decreases the cross-sectional area of the chamber <NUM> towards its rear end <NUM>. This arrangement reduces the volume of the chamber <NUM> towards its rear end <NUM> which may restrict the flow of adhesive <NUM> thereto. Reducing the volume of the chamber <NUM> towards its rear end <NUM> may cause a pressure in that region of the chamber <NUM> to be exerted on the adhesive, similar to the pressure applied at the front end <NUM>, thereby improving the uniformity of the pressure under which the adhesive <NUM> is initially laid down on the application surface <NUM>.

In this example, the height of the chamber <NUM> at its front and rear ends <NUM>, <NUM> is substantially equal. This arrangement serves to promote the formation of a stratum or layer of adhesive <NUM>, the upper region of which is generally indicated by line <NUM>, immediately above the application surface <NUM>, which flows unimpeded from the front end <NUM> of the chamber <NUM> to the rear end <NUM>. The stratum of adhesive <NUM> is continuously resupplied with the entrainment of adhesive <NUM> entering the chamber <NUM> as the tool <NUM> is moved along the adhesive deposition path <NUM>. This helps to prevent the formation of dead areas of recirculating adhesive <NUM> within the chamber <NUM>, thereby minimising waste.

Such dead areas of adhesive <NUM> are also avoided by ensuring that the cross-sectional area of the chamber <NUM> continuously decreases towards the front and rear ends <NUM>, <NUM> of the chamber <NUM>, as opposed to decreasing over a series of intermittent steps that could give rise to pockets of recirculating adhesive <NUM> within the chamber <NUM>. For example, in the present example, the second baffle <NUM> is configured such that the height of the chamber <NUM>, and so the cross-sectional area of the chamber <NUM>, continuously decreases towards the rear end <NUM> of the chamber <NUM>. The top potion <NUM> is also configured such that the height of the chamber <NUM> continuously decreases towards the front end <NUM> of the chamber <NUM> through the use of the first baffle <NUM>.

More specifically, the top portion <NUM>, through the combination of the first and second baffles <NUM>, <NUM>, may be configured such that the height of the chamber <NUM> increases and subsequently decreases in the direction of the front end <NUM> of the chamber <NUM>. This initial increase in the height contributes to an overall increase in the volume of the chamber <NUM> in comparison to the known tool <NUM>. Moreover, the overall length of the tool <NUM> is at least <NUM>, which is more than the length of the known tool <NUM>. Specifically, the overall length of the tool <NUM> of this example is <NUM>. This too contributes to a comparative increase in the volume of the chamber <NUM>, providing the advantage of the tool <NUM> being able to accommodate an increased amount of adhesive <NUM> within the chamber <NUM> during use. A chamber which has a larger volume will hold an increased volume of adhesive, and this helps the operator provide a consistent bead of adhesive.

The side portions <NUM> may be substantially parallel and since the height of the chamber <NUM> at its front and rear ends <NUM>, <NUM> may be substantially equal, the cross-sectional areas of the front and rear ends <NUM>, <NUM> may also be substantially equal. Accordingly, the pressure exerted by the adhesive <NUM> on the boundaries of the front and rear regions of the chamber <NUM> is considerably equal, further improving the uniformity of the pressure under which the adhesive <NUM> is initially laid down on the application surface <NUM>.

The side portions <NUM> may forwardly extend ahead of the front end <NUM> of the chamber <NUM> defining a channel <NUM> located ahead of the chamber <NUM>. The channel <NUM> is used to collect any excess adhesive <NUM> that might spill from the front end <NUM> of the chamber <NUM> in the event the supply rate exceeds the application rate of the adhesive <NUM>. This arrangement prevents adhesive <NUM> from spilling around and being drawn in underneath the leading edges of the side portions <NUM>, between the bottom surfaces of the side portions <NUM> and the application surface <NUM>, as the tool <NUM> is moved along the adhesive deposition path <NUM>.

Moreover, the channel <NUM> also provides the operator <NUM> a visual indication, during use, on whether the application rate of adhesive <NUM> needs to be altered. Ideally, the operator <NUM> would be able to see adhesive <NUM> at the front end <NUM> of the chamber <NUM>, indicating that the chamber <NUM> is full of adhesive <NUM>, as the bead of the adhesive <NUM> is laid down, but the existence of excess adhesive <NUM> in the channel <NUM> could be an indication that the application rate of the adhesive <NUM> needs to be increased relative to the supply rate.

<FIG> show another example of an adhesive deposition tool <NUM> comprising a top portion <NUM>, two side portions 16a, 16b and a supply channel <NUM>. An inner surface <NUM> of the top portion <NUM> defines the upper boundary of an open-ended chamber <NUM> within the volume of the tool <NUM>, and inner surfaces <NUM> of the two side portions 16a, 16b respectively define side boundaries of the chamber <NUM>. The chamber <NUM> comprises a front end <NUM> and a rear end <NUM>, and, in use, the application surface <NUM>, onto which structural adhesive is deposited from the tool <NUM>, defines the lower boundary of the chamber <NUM>.

This example differs from the previous example of the tool <NUM> in that one of the side potions 16a, 16b is configured such that the width of the chamber <NUM> decreases towards the front end <NUM> of the chamber <NUM>, which provides the progressive decrease in the cross-sectional area of the chamber <NUM> towards its front end <NUM>. Specifically, the side potion 16a comprises a baffle <NUM> inwardly pitched towards the front end <NUM> of the tool <NUM>. This arrangement reduces the volume of chamber <NUM> towards its front end <NUM>, which restricts the flow of adhesive <NUM> thereto and increases the pressure exerted by the adhesive <NUM> on the boundaries of the chamber <NUM> in that region of the chamber <NUM> relative to the known tool <NUM>. This increase in pressure pushes the adhesive <NUM> onto the application surface <NUM> below the front end <NUM> of the chamber <NUM>, improving the connection that is initially established therebetween and increasing the uniformity of the pressure under which the adhesive <NUM> is initially laid down on the application surface <NUM> before it exits from the rear end <NUM> of the chamber <NUM> to form the bead of adhesive <NUM>.

The other side portion 16b may be straight. This is particularly advantageous if, during use, the tool <NUM> is being guided along the adhesive deposition path <NUM> using a physical guide as it maximises the contact between the tool <NUM> and the physical guide, ensuring the stability of the tool <NUM> as it is moved along the adhesive deposition path <NUM> by the operator <NUM>. In an alternative example, the outer surface of the side portion 16a comprising the baffle <NUM> may also be straight, so it too can be used to achieve maximum contact between the tool <NUM> and a physical guide during use.

The side portions 16a, 16b may forwardly extend ahead of the front end <NUM> of the chamber <NUM> defining a channel <NUM> located ahead of the chamber <NUM>. As with the previous example, the channel <NUM> is used to collect any excess adhesive <NUM> that might spill from the front end <NUM> of the chamber <NUM> in the event the supply rate exceeds the application rate of the adhesive <NUM>. This arrangement prevents adhesive <NUM> from being drawn in underneath the side portions <NUM> as the tool <NUM> is moved along the adhesive deposition path <NUM> and also provides the operator <NUM> a visual indication, during use, on whether the application rate of adhesive <NUM> needs to be changed.

With reference to <FIG>, the top portion <NUM> comprises a baffle <NUM> downwardly pitched towards the rear end <NUM> of the tool <NUM> so as to decrease the height of the chamber <NUM> towards its rear end <NUM>, resulting in a progressive decrease in the cross-sectional area of the chamber <NUM> towards its rear end <NUM>. This arrangement reduces the volume of chamber <NUM> towards its rear end <NUM>, restricting the flow of adhesive <NUM> thereto.

The height of the chamber <NUM> at its front end <NUM> is greater than at its rear end <NUM>. However, due to the inwardly pitched baffle <NUM> on the side potion 16a, the cross-sectional areas of the front and rear end <NUM>, <NUM> of the chamber <NUM> are substantially equal. This has the advantage that the pressure exerted by the adhesive <NUM> on the boundaries of the front and rear regions of the chamber <NUM> is considerably equal, improving the uniformity of the pressure under which the adhesive <NUM> is initially laid down on the application surface <NUM>.

It will be appreciated that various changes and modifications can be made to the tool <NUM> without departing from the scope of the invention as defined in the appended claims.

For example, one of the examples shown includes a top portion <NUM> configured such that the height of the chamber <NUM> decreases towards the front end <NUM> of the chamber <NUM>, and the other example shows a side potion 16a configured such that the width of the chamber <NUM> decreases towards its front end <NUM>. However, other examples/ variants of the tool <NUM> are envisaged in which the top portion <NUM> and at least one of the side portions 16a, 16b are configured such that both the height and width of the chamber <NUM> concurrently decrease in order to reduce the cross-sectional area of the chamber <NUM> towards its front end <NUM>.

Similarly, it will be appreciated by the skilled reader that the cross-sectional area at the front and rear ends <NUM>, <NUM> of the chamber <NUM> need not be substantially equal. The tool <NUM> may be configured such that the cross-sectional area at the front end <NUM> of the chamber <NUM> is smaller than the cross-sectional area at the rear end <NUM>. Such a configuration may be used, for example, when one wishes to increase the pressure applied by the adhesive <NUM> to the front region of the tool <NUM> relative to its rear region. Alternatively, the tool <NUM> may be configured such that the cross-sectional area at the front end <NUM> of the chamber <NUM> is greater than the cross-sectional area at the rear end <NUM>. This configuration may be used, for example, to prevent a situation in which the flow of adhesive <NUM> towards the front end <NUM> of the chamber <NUM> is overly restricted, preventing the chamber <NUM> from filling completely, as might occur when the adhesive <NUM> is supplied at a low temperature, and so an increased viscosity. In both situations, however, the uniformity of the pressure under which the adhesive <NUM> is applied to the application surface <NUM> along the length of the tool <NUM> is improved when compared with the known tool <NUM>.

It will also be appreciated by the skilled reader that the baffles <NUM>, <NUM>, <NUM>, used to restrict the flow of adhesive <NUM> within the chamber <NUM>, do not necessarily need to be straight, but could instead comprise a non-straight profile, provided that the height and/or width of the chamber <NUM> decreases towards the front end <NUM> or, in the case of the second baffle <NUM>, the rear end <NUM> of the chamber <NUM>. For example, one or more of the baffles <NUM>, <NUM>, <NUM> might have a convex profile tapering towards the front or rear end <NUM>, <NUM>, which could aid the development of the stratum of adhesive <NUM> at the bottom of the chamber <NUM> and also help to prevent the formation of "dead areas" of adhesive <NUM> within the chamber <NUM>.

Claim 1:
An adhesive deposition tool (<NUM>) for applying a bead of structural adhesive (<NUM>) onto an application surface (<NUM>) of a wind turbine blade component, the tool comprising:
a top portion (<NUM>) defining an upper boundary of an open-ended chamber (<NUM>), the chamber comprising a front end (<NUM>) and a rear end (<NUM>), the rear end being the end from which adhesive is deposited onto the surface when the tool is moved along the surface;
two side portions (<NUM>) defining side boundaries of the chamber; and,
a supply channel (<NUM>) for supplying adhesive to the chamber,
wherein the top portion (<NUM>) and/or at least one side portion (<NUM>) is configured such that the height and/or the width of the chamber (<NUM>) decreases towards the front end of the chamber; characterised in that
the top portion (<NUM>) further comprises a baffle (<NUM>) downwardly pitched towards the rear of the tool so as to decrease the height of the chamber (<NUM>) towards the rear end of the chamber.