GB2533296A

GB2533296A - Masking tools

Info

Publication number: GB2533296A
Application number: GB1422263.2A
Authority: GB
Inventors: Williams Thomas; Wagstaff Lee; Beswick Robert
Original assignee: Airbus Operations Ltd
Current assignee: Airbus Operations Ltd
Priority date: 2014-12-15
Filing date: 2014-12-15
Publication date: 2016-06-22

Abstract

A masking tool 1 for use when coating the head of a fastener 4 protruding from an aerospace component. The masking tool 1 comprises a collar 2 for surrounding the head of the fastener, and a handle 10 connected to the collar. The collar comprises a lower edge 3 for contacting the surface 5 of the aerospace component. In use, when the collar is received over the head of the fastener the lower edge creates a boundary surrounding the head of the fastener, within which the head of the fastener 4 may be coated. Also claimed is a method for using such a tool. Further claimed is a kit of parts wherein there are multiple variously sized collars which can be interchangeable with a single handle.

Description

MASKING TOOLS

FIELD OF THE INVENTION

[0001] The present invention concerns masking tools. More particularly, but not exclusively, this invention concerns a masking tool for use when coating the head of a fastener protruding from an aerospace component. The invention also concerns a method of coating the head of a fastener using such a masking tool and a masking tool kit for use when coating the head of a fastener.

BACKGROUND OF THE INVENTION

[0002] The head of a fastener may remain exposed after the fastener has been connected to another component. In some applications it is desirable to apply a coating over the exposed head of such a fastener for aesthetic or performance reasons. For example, in aerospace applications, a coat of paint or other protective layer may be applied to the head of a fully torqued fastener after it has been fastened to part of a wing or other aircraft component. Typically, the coating is applied over the fastener by an operator with a brush and/or sponge in a 'free-hand' manner. This may lead to wasted coating material if too wide an area is covered and/or a non-uniform appearance if different amounts of coating material are applied around different fasteners. This 'free-hand' approach may be time consuming in terms of the time taken to apply the coating and/or in ternis of wasted time spent cleaning off misapplied coating material.

[0003] The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved means of applying a coating to the head of an aircraft fastener protruding from the surface of an aircraft component. -2 -

SUMMARY OF THE INVENTION

[0004] The present invention provides, according to a first aspect, a masking tool for use when coating the head of a fastener protruding from an aerospace component, the masking tool comprising a collar for surrounding the head of the fastener, and a handle connected to the collar, wherein the collar comprises a lower edge for contacting the surface of the aerospace component such that, in use, when the collar is received over the head of the fastener the lower edge creates a boundary surrounding the head of the fastener, within which the head of the fastener may be coated.

[0005] The lower edge of the collar may be defined as the edge of the collar which, in use, is adjacent to the surface of the aerospace component. In use, the lower edge of the collar may contact the surface of the aerospace component along the majority of its length.

[0006] It will be appreciated that the term "protruding" as used herein refers to an exposed portion on the surface of an aerospace component, and that masking tools in accordance with the present invention may be used with fasteners that project beyond and/or are substantially flush with the surface of the aerospace component.

[0007] The collar may comprise one or more side walls which define a central aperture arranged to receive the head of the fastener. Thus, the collar may be tubular. The collar may comprise an inner surface which faces towards the centre of the central aperture. The collar may comprise an outer surface which faces away from the centre of the central aperture. The diameter of the central aperture may be greater than the diameter of the head of the fastener such that, in use, the inner surface of the collar is spaced apart from the top and sides of the head of a fastener received in the collar. Providing an aperture with a larger diameter than the head of the fastener to be coated may allow access to the -3 -sides of the head of the fastener, thereby facilitating improved coverage of the head with the coating.

[0008] The side walls of the collar may have a radial thickness. The radial thickness of the side walls may vary with respect to the longitudinal axis of the collar. Thus, the collar may be a tube-like structure having a non-constant wall thickness.

[0009] The collar may have a depth. The depth of the collar may be greater than the radial thickness of the side walls of the collar. The height of the head of the fastener may be defined as the length of the portion of the fastener that protrudes from the surface. The depth of the collar may be greater than the height of the head of the fastener. Having a collar with a substantial depth may reduce the risk of a paint brush and/or sponge slipping outside the collar during use thereby making it easier to apply the coating to the fastener and/or reducing the risk of wasting coating material.

[0010] The collar may comprise a lower portion. The lower portion may be defined as the region of the collar adjacent to the lower edge. In the lower portion of the collar, the thickness of the collar wall(s) may decrease with proximity to the lower edge. The lower part of the collar may taper to form a thinner lower edge. Providing a thinner lower edge may improve the contact between the component surface and the lower edge, particularly where the component surface is curved. Providing a thinner lower edge may also reduce the risk of the masking tool transferring excess paint from the region of one fastener to another. It will be appreciated that the lower part of the collar may taper to form a lower edge that has a radial thickness less than the thickness of the rest of the collar (excluding any tapered upper region, if present). The radial thickness of the collar at the lower edge may be substantially less than the mean radial thickness of the collar. The outer and inner surfaces of the collar may meet at the lower edge. The lower edge may be pointed and/or form a knife-edge. It may be that the outer surface of the collar is inclined at an angle to the longitudinal axis of the collar in the lower region to form a taper. It may be that the inner surface of the collar extends parallel to the longitudinal axis of the collar in the -4 -lower region. The angle between the inner and outer surfaces of the collar at the lower edge may be between 20 degrees and 40 degrees, for example between 25 degrees and 35 degrees.

[0011] It may be that the collar has an upper portion located at the opposite end of the collar to the lower edge. It may be that the inner surface of the collar in the upper portion is arranged to guide a brush and/or sponge towards the centre of the collar when the mask is in use. Providing a guide for a brush and/or sponge may reduce the risk of the operator painting outside the mask and/or increase the ease of use of the masking tool. The upper portion may be defined as the region of the collar adjacent to an upper edge. It may be that in the upper portion the thickness of the collar decreases with proximity to the upper edge. It may be that the inner surface of the collar in the upper region is inclined at an angle to the longitudinal axis of the collar to form a guide for a brush and/or sponge. It may be that the outer surface of the collar extends parallel to the longitudinal axis of the collar in the upper region. The outer and inner surfaces of the collar may meet at the upper edge. Thus, the upper edge may be pointed and/or form a knife edge. The angle between the inner and outer surfaces at the upper edge may be between 25 and 45 degrees, for example between 30 and 40 degrees.

[0012] It may be that the collar is substantially cylindrical. A cylindrical collar may be easier to manufacture. It will be appreciated that the tubular body may have a non-circular cross section depending on the shape of the fastener to be coated. For example the tubular body may have a hexagonal or square cross-section.

[0013] The collar may be more rigid than the handle. Providing a rigid collar in combination with a relatively flexible handle may allow the collar to provide a solid boundary around the area to be coated while the compliance in the handle may improve the contact between the collar and the surface. -5 -

[0014] The handle may comprise a bend arranged to allow the fingers of a user to be located between the lower surface of the handle and the surface of the aerospace component when the lower edge of the collar is in contact with the surface of the component. The handle may comprise a first portion which in use is held by a user and a second portion inclined at an angle to the first portion and which connects the first portion to the collar such that the collar is displaced away from the longitudinal axis of the first portion of the handle. Displacing the collar away from the longitudinal axis of the first portion of the handle may increase the ease of use of the masking tool by allowing a user's fingers to wrap around the handle when the collar is in use.

[0015] It may be that the handle of the masking tool comprises a fold arranged to increase the flexibility of the handle. The fold may be arranged to increase the flexibility of the handle with respect to a handle made of the same material which does not have a fold. The fold may be arranged to allow a first portion of the handle to move relative to the second portion of the handle. Increasing the flexibility of the tool may allow a better contact between the lower edge of the collar and the surface of the aerospace component, thereby reducing the risk of the coating fluid escaping underneath the collar.

[0016] It may be that the handle and collar are formed as a single component. Forming the handle and collar as a single component may reduce manufacturing costs.

[0017] It may be that the handle and collar are formed separately. Forming the handle and collar separately may facilitate the design of masking tools having interchangeable collars for use with differently sized fasteners, thereby increasing the range of applications in which the masking tool can be used. In the case that the collar is formed separately from the handle, the handle may comprise a collar receiving portion in which the collar is located when the mask is in use. The collar receiving portion may be located at a first end of the handle. The collar receiving portion may be resiliently biased towards a position in which the collar receiving portion grips a collar received in the receiving portion. It may be that the receiving portion comprises an annulus formed at the first end -6 -of the handle. It may be that the annulus comprises a gap in its circumference such that the sides of the annulus can be pushed apart by the insertion of a collar therein. It may be that each collar comprises a recess in its outer surface arranged to receive a portion of the handle, for example a portion of the annulus therein. The outer diameter of the collar may be greater in the upper region of the collar than in the lower region of the collar such that the collar can sit in the receiving portion.

[0018] It may be that at least the handle is made from metal, for example stainless steel. Providing a handle made from metal may allow the masking tool to be cleaned after use using a solvent.

[0019] It may be that at least the collar is made from nylon. Providing a non-metal collar may reduce the risk of the collar damaging the surface of the aerospace component and/or reduce manufacturing costs. It may be that the collar and handle are both made from nylon. Making the masking tool from nylon may facilitate lightweight and/or flexible masking tools and/or reduce manufacturing costs.

[0020] It will be appreciated that masking tools in accordance with the present invention are designed to be held by the operator in one hand while applying the coating to the fastener with the other hand. Consequently, the handle may be arranged to be gripped by an operator with one hand during use. The handle may have a length of between 150 and 250 mm, for example between 200 and 220 mm.

[0021] The aerospace component may be an airframe panel, for example a wing panel. The surface may be metal, for example aluminium or a composite. The fastener may comprise more than one component. For example, the fastener may comprise a bolt and a threaded nut arranged to engage the bolt. The head of the fastener may be defined as any portion of the fastener that protrudes from the surface of the aerospace component. The head of the fastener may be defined as an end portion of the fastener. For example the head of the fastener may comprise a portion of the bolt and the nut, or a portion of the bolt only. The fastener may be a fully torqued aircraft fastener for example a bolt and threaded nut, for example a 5/16 inch (approx. 7.94 mm) nut. It will be appreciated that the masking tool may be used with a wide variety of fasteners. The collar may be suitable for use with fasteners having heads with a diameter of between 4 mm and 40 mm. The collar may have an inner diameter between 20 mm and 50 mm, for example between 30 mm and 40 mm.

[0022] According to a second aspect of the invention, there is provided a method of coating the head of a fastener protruding from an aerospace component, using a masking tool comprising a collar for surrounding the head of the fastener, and a handle connected to the collar, the method comprising the step of placing a lower edge of the collar in contact with the surface of the aerospace component such that the head of the fastening is received within the collar and then applying a coating to the area inside the collar.

[0023] 'The coating may be applied with a brush and/or a sponge. It will be appreciated that the coating may be any one of a wide variety of flowable materials, for example the coating may be a paint.

[0024] It may be that the method includes a step of cleaning the mask with a solvent after use. It will be appreciated that the solvent used will depend on the coating material.

[0025] The method may comprise a step of producing the tool using an additive manufacturing process, for example selective laser sintering. Using additive manufacturing to produce the tool may reduce manufacturing costs while providing masking tools having a wide variety of shapes. For example the method may comprise a step of producing the collar and/or the handle using an additive manufacturing process. The method may comprise a step of forming the collar and the handle as a single component using an additive manufacturing process. -8 -

[0026] According to a third aspect of the invention there is provided a method of applying a coating to the heads of first and second fasteners protruding from the surface of an aerospace component, using a masking tool comprising a collar and a handle connected to the collar, wherein the heads of the first and second fasteners have different diameters, the method comprising: using a masking tool comprising a handle and a first collar having a first diameter to coat the first fastener in accordance with the method described above, swapping the first collar for a second collar having a second, different, diameter, and then using the masking tool comprising the handle and the second collar to coat the second fastener in accordance with the same method. Using a masking tool with interchangeable collars to coat differently sized fastener heads may reduce the number of tools required in the manufacturing process thereby simplifying the manufacturing process.

[0027] According to a fourth aspect of the invention, there is provided a kit for use when coating the head of a fastener protruding from an aerospace component, the kit comprising a plurality of collars each collar being suitable for surrounding the heads of a fastener having a differing diameter and a handle arranged for connection to at least one of the collars. It may be that each collar has a different inner diameter to any other collar. It may be that each collar has the same outer diameter as every other collar.

[0028] The kit may comprise a handle and a plurality of separate collars. The handle may comprise a receiving portion arranged to receive any one of the collars.

[0029] It may be that the kit comprises a plurality of masking tools, each masking tool comprising a collar connected to a different handle. In the case that the kit comprises a plurality of masking tools, the kit may further comprise a holder, for example a ring. It may be that each of the plurality of masking tools is mounted on the holder. For example, the handle of each masking tool may comprise a hole through which the holder passes. -9 -

[0030] According to a fifth aspect of the invention, there is provided a masking tool, the masking tool comprising a collar that surrounds the head of a fastener protruding from an aerospace component, and a handle connected to the collar, wherein the collar further comprises a lower edge, the lower edge being in contact with the surface of the aerospace component such that the collar creates a boundary surrounding the head of the fastener, within which the head of the fastener may be coated. The inner surface of the collar may be spaced apart from the head of the fastener such that there is a gap between the collar and the fastener.

[0031] It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa.

DESCRIP HON OF THE DRAWINGS

[0032] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: [0033] FIG. 1A, 1B and 1C show a perspective view of (a) the top, (b) the underside and (c) a cross-section of a masking tool according to a first embodiment of the invention; and [0034] FIG. 2A, 2B and 2C show a perspective view of (a) the top, (b) the underside and (c) a cross-section of a masking tool according to a second embodiment of the invention.

DETAILED DESCRIPTION

[0035] FIG. IA shows a masking tool 1 in accordance with a first example embodiment. The masking tool 1 comprises a tubular nylon collar 2 which in FIG. 1A is shown -10 -surrounding the head of a fastener 4 which is protruding from a portion of a wing surface 5. The lower edge 3 of the collar 2 is in contact with the surface 5. The tubular collar 2 sits within a stainless steel holding ring 6 which has a small gap 8 in its circumference. The holding ring 6 is formed on one end of a stainless steel handle 10. The handle 10 extends radially away from the holding ring 6 from a point on the circumference of the ring 6 which is spaced apart from the gap 8 by 180 degrees. The handle I 0 comprises a first portion I Oa a second portion I Ob and a third portion I Oc. The first portion I Oa is adjacent to the ring 6 and extends in substantially the same plane as the ring 6. The second portion I Ob extends between the first portion I Oa and the third portion I Ob and is inclined upwards at an angle to the first portion I Ob. The third portion I Oc is connected at one end to the second portion 10b and extends parallel to the first portion 10a. A hole 12 is formed in the distal end of the handle 10 (in the third section 10c). The underside of the masking tool I can be seen in FIG. 1B. FIG I C shows a cross-sectional view of the collar 2. As shown in FIG. IC, the radial thickness of the collar 2 varies along the longitudinal axis of the collar 2. The outer surface 9 of a lower portion 2a of the collar 2 is inclined with respect to the longitudinal axis of the collar. The inner surface 7 of the lower portion 2a extends parallel to the longitudinal axis of the collar 2 such that the thickness of the collar is reduced in the region of the lower edge 3 (that is to say the lower region of the collar 2 tapers to a point at lower edge 3). At the other end of the collar 2, the inner surface 7 of an upper portion 2b of the collar 2 is inclined with respect to the longitudinal axis of the collar 2 while the outer surface 9 extends parallel to the same axis. A circumferential groove I I is formed in the outer surface 9 of the collar 2 around halfway along the length of the collar 2.

[0036] In use, the user inserts the collar 2 into the holding ring 6 until the ring 6 is located in the circumferential groove 11. As the user inserts the collar 2 into the ring 6 the sides of the ring 6 located either side of the gap 8 are pushed apart by the inclined outer surface 9 of the lower region 2a so that the ring 6 securely grips the collar 2. Consequently, masking tools in accordance with the present embodiment provide a secure connection between the interchangeable collar 2 and the handle 10. Once a collar 2 of the appropriate dimension has been inserted into the tool the user grasps the handle 10 and places the collar 2 over the fastener 4 with the lower edge 3 in contact with the surface 5. A paint brush (not shown) is then used to apply a layer of paint over the head of the fastener 4 and the surrounding portion of the surface 5 located within the boundary formed by the collar 2. Thus, masking tools in accordance with the first embodiment define a boundary which may make it easier to apply a coat of paint to the head of a fastener in a consistent manner. Using a masking tool in accordance with the present embodiment may also increase the speed with which paint can be applied and reduce wastage by reducing the area of the surface of the component which is painted. Applying the paint to a fastener using a masking tool in accordance with the present embodiment may also improve the aesthetic appearance of the aircraft as substantially the same area is painted for each fastener of the same diameter.

[0037] Forming the metal handle I 0 and nylon collar 2 as separate components may facilitate the use of interchangeable collars having different diameters for use with a variety of fasteners, thereby increasing the utility of the paint mask 1. Masking tools in accordance with the present invention may be used with other fasteners having different diameters by replacing the collar 2 shown in FIG. 1 with another collar (not shown) having different internal dimensions.

[0038] The tapered lower portion 2a of the collar 2 means that lower edge 3a effectively forms a knife edge, and consequently, masking tools in accordance with the present embodiment may improve the definition of the edge of the painted area providing a better aesthetic appearance and reducing the risk of the tool 1 leaving unwanted paint marks on the surface 5. The inclined outer surface 9 of the lower portion 2b of the collar 2 may also make inserting the collar 2 into the holding ring 6 easier.

[0039] The inclined inner surface 7 of the upper portion 2b acts as a guide which directs the paint brush towards the centre of the aperture, thereby increasing the ease of use of the tool.

-12 - [0040] Having a metal handle may allow the handle and ring to be cleaned with a solvent after use. Using a solvent may provide a quick and easy way of cleaning the tool.

[0041] FIG. 2A shows a masking tool 101 in accordance with a second example embodiment. Only those elements of this embodiment which differ with respect to the first embodiment will be discussed here. Like features with respect to FIG. 1 are indicated with like references. In contrast to the embodiment of FIG. 1 where the collar 2 sits within the holding ring 6, the nylon masking tool 101 of the second embodiment comprises a handle 110 and collar 102 which are formed as a single component using selective laser sintering. The handle 110 also includes triangular bracing portions 114 extending between the first 110a and second 110b handle portions and between the second 110b and third 110c handle portions. The underside of the masking tool 101 of the second embodiment is shown in FIG. IC and a cross-section through the collar 102 and a portion of the handle 110 of the masking tool 101 is shown in FIG 2C.

[0042] Bracing portions 114 provide additional structural strength to the handle 110 but are sized to allow some rotation of the handle portions 110a, 110b and 110c relative to each other. Consequently, masking tools 101 in accordance with the present embodiment may provide an improved contact between the collar 102 and the surface 105 as the compliance of the handle 110 allows the tool 101 to better conform to variation in angles of the surface 105.

[0043] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described. For example, while the tools described above are made from stainless steel and/or nylon it will be appreciated that a wide variety of materials may be used. It will also be appreciated that -13 -masking tools in accordance with the present invention may be used in non-aerospace applications when coating the head of a fastener protruding from a component.

[0044] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims

-14 -CLAIMS1 A masking tool for use when coating the head of a fastener protruding from an aerospace component, the masking tool comprising a collar for surrounding the head of the fastener, and a handle connected to the collar, wherein the collar comprises a lower edge for contacting the surface of the aerospace component such that, in use, when the collar is received over the head of the fastener the lower edge creates a boundary surrounding the head of the fastener, within which the head of the fastener may be coated.
2. A masking tool according to claim 1, wherein the lower part of the collar tapers to form a thinner lower edge.
3 A masking tool according to claim 1 or claim 2, wherein the collar has an upper portion located at the opposite end of the collar to the lower edge, and wherein the upper portion comprises an inner surface arranged to guide a brush and/or sponge towards the centre of the collar when the mask is in use.
4. A masking tool according to any previous claim, wherein the handle comprises a bend arranged to allow the fingers of a user to be located between the lower surface of the handle and the surface of the aerospace component when the lower edge of the collar is in contact with the surface of the component.
5. A masking tool according to any previous claim, wherein the collar is substantially cylindrical.
6. A masking tool according to any previous claim, wherein the handle of the coating mask comprises a fold arranged to increase the flexibility of the handle.

-15 -
7. A masking tool according to any previous claim, wherein the handle and collar are formed as a single component.
8. A mask tool according to any of claims 1 to 7, wherein the handle and collar are formed separately and wherein the handle comprises a collar receiving portion in which the collar is located when the mask is in use.
9. A masking tool according to any previous claim, wherein at least the handle is made from metal.
10. A masking tool according to any previous claim, wherein at least the collar s made from nylon.
I I A method of coating the head of a fastener protruding from an aerospace component, using a masking tool comprising a collar for surrounding the head of the fastener, and a handle connected to the collar, the method comprising the step of placing a lower edge of the collar in contact with the surface of the aerospace component such that the head of the fastening is received within the collar and then applying a coating to the area inside the collar..
12. A method of applying a coating to the heads of first and second fasteners protruding from the surface of an aerospace component, using a masking tool comprising a collar and a handle connected to the collar, wherein the heads of the first and second fasteners have different diameters, the method comprising: using a masking tool comprising a handle and a first collar having a first diameter to coat the first fastener in accordance with the method of claim I I, swapping the first collar for a second collar having a second, different, diameter, and then using the masking tool comprising the handle and the second collar to coat the second fastener in accordance with the method of claim 11.

-16 -
13. A method according to any of claims 11 or 12, wherein the coating is a paint.
14. A method according to any of claims 11 to 13, wherein the method includes a step of cleaning the mask with a solvent after use.
A kit for use when coating the head of a fastener protruding from an aerospace component, the kit comprising a plurality of collars suitable for surrounding the heads of fasteners having differing diameters and a handle arranged for connection to at least one of the collars.
16. A kit according to claim 15, wherein the handle comprises a receiving portion arranged to receive any one of the collars.
17. A kit according to claim 15, wherein the kit comprises a plurality of masking tools mounted on a holder, each masking tool comprising one of the plurality of collars connected to a different handle.
18. A mask substantially as herein described with reference to the drawings.
19. A method of coating a fastener substantially as herein described with reference to the drawings.