DEPOSITION OF SEALANT OR SIMILAR MATERIALS

Abstract

An applicator for the deposition of sealant onto a surface of a workpiece is disclosed including at least one inlet for depositing sealant on to a surface or a nozzle-receiving space for receiving a nozzle comprising at least one inlet for depositing sealant on to a surface; at least one sealant-contacting surface for contacting sealant deposited onto the surface through the inlet as the applicator is moved across said surface, thereby forming a film of sealant on the surface; at least one spacer for contacting a surface onto which sealant is to be deposited and for maintaining the sealant-contacting surface in spaced relationship with the surface; the applicator being configured to facilitate the formation of films of different widths.

Claims

1. An applicator for the deposition of sealant onto a surface of a workpiece, the applicator comprising: at least one inlet for depositing sealant on to a surface or a nozzle-receiving space for receiving a nozzle comprising at least one inlet for depositing sealant on to a surface; at least one sealant-contacting surface for contacting sealant deposited onto the surface through the inlet as the applicator is moved across said surface, thereby forming a film of sealant on said surface; at least one spacer for contacting a surface onto which sealant is to be deposited and for maintaining the sealant-contacting surface in spaced relationship with the surface; and, the applicator being configured to facilitate the formation of films of different widths.

2. The applicator according to claim 1 comprising a plurality of inlets, the inlets being configured to facilitate the formation of films of different widths, wherein the plurality of inlets are arranged laterally across the applicator.

3. The applicator according to claim 1 wherein at least one inlet is elongate, a long axis of the inlet being normal to the intended direction of motion of the applicator, and configured to be substantially parallel to a surface on which the film is to be deposited.

4. The applicator according to claim 1 comprising at least one inlet reservoir for receiving sealant from at least one inlet.

5. The applicator according to claim 4 comprising a plurality of inlet reservoirs for receiving sealant, the plurality of inlet reservoirs being configured to facilitate the formation of films of different widths.

6. The applicator according to claim 5 wherein the plurality of inlet reservoirs are arranged laterally across the applicator.

7. The applicator according to claim 5 wherein adjacent inlet reservoirs are separated by a partition to inhibit movement of sealant between adjacent inlet reservoirs.

8. The applicator according to claim 4, wherein at least one inlet reservoir has an open face for placement proximate to the surface on to which sealant is to be deposited, and at least one, each inlet reservoir is configured to provide a covered space when the applicator is in contact with a surface onto which sealant is to be deposited.

9. The applicator according to claim 4, comprising at least one overflow outlet for the egress of excess sealant from an inlet reservoir, the overflow outlet being in fluid communication with an inlet reservoir.

10. The applicator according to claim 1 comprising a plurality of sealant-contacting surfaces, wherein more than one sealant-contacting surface is provided with at least one spacer for contacting a surface onto which sealant is to be deposited and for maintaining the sealant-contacting surface in spaced relationship with the surface on which sealant is to be deposited, and at least one sealant-contacting surface is substantially devoid of such spacers.

11. The applicator according to claim 1 comprising a plurality of sealant-contacting surfaces mutually spaced along a length of the applicator, a space for the collection of sealant being provided between adjacent sealant-contacting surfaces, wherein each sealant-contacting surface comprises a flat portion.

12. The applicator according to claim 1 wherein at least one sealant-contacting surface is provided by a baffle, wherein at least one baffle comprises a curved surface and a flat surface configured to be adjacent to a surface on which sealant is to be deposited.

13. A method of forming a film of sealant on a workpiece, the method comprising: sensing a width of a surface of the workpiece; contacting sealant with the surface; and moving at least one sealant-contacting surface over the sealant, thereby forming a film on the surface, the width of said film depending on the sensed width of the surface.

14. A method according to claim 13 in which the workpiece is a vehicle component, such as an aircraft component.

15. A method according to claim 13 comprising sensing a width of the surface using electromagnetic radiation.

16. A method according to claim 13 in which the surface of the workpiece face substantially downwards, and the method comprises use of an applicator, the applicator being used in an inverted orientation, and in which contacting sealant with the surface comprises at least partially filling an inlet reservoir with liquid.

17. A method according to claim 16, wherein the applicator comprises one or more spacers for contacting a surface onto which sealant is to be deposited and for maintaining the sealant-contacting surface in spaced relationship with the surface, the method comprising urging the one or more spacers into contact with the surface onto which a film is to be deposited and maintaining contact between the one or more spacers and the surface onto which a film is to be deposited.

18. An apparatus for forming a film of sealant on a surface of a workpiece, the apparatus comprising: one or more sensors for sensing a width of a surface of a workpiece; an applicator mount for mounting an applicator for forming a film on a surface of a workpiece; a means of moving a mounted applicator for forming a film on a surface of a workpiece such that an applicator fixed to said mount is movable along a surface of a workpiece; a plurality of outlets for supplying sealant to corresponding sealant inlets provided in an applicator; and one or more sealant supply means for moving sealant from a source of sealant to said outlets, the apparatus being configured to supply sealant to one or more of the plurality of outlets dependent on a sensed width of a surface of the workpiece as determined by one or more of the sensors.

19. An apparatus according to claim 18 in which at least one of the sensors is configured so that the sensors move as a mounted applicator moves.

20. An apparatus according to claim 18 in which at least one of the sensors is operable to emit electromagnetic radiation and sense electromagnetic radiation, the sensed radiation determining a width of the surface and/or the apparatus comprises a biasing means for urging a mounted applicator into contact with a surface on to which a film is to be formed.

Description

DESCRIPTION OF THE DRAWINGS

[0089] FIG. 1 shows a perspective view of the underside of an example of an embodiment of an applicator in accordance with the first aspect of the present invention;

[0090] FIG. 2 shows a cross-sectional perspective view of part of the applicator of FIG. 1;

[0091] FIG. 3 shows a perspective view of an example of an embodiment of an apparatus in accordance with the third aspect of the present invention; and

[0092] FIG. 4 shows a schematic representation of an example of an embodiment on a method of depositing sealant in accordance with the second aspect of the present invention.

DETAILED DESCRIPTION

[0093] FIGS. 1 and 2 shows perspective views of the underside of applicator 1 in accordance with the first and second aspects of the present invention. FIG. 2 is a cross-sectional perspective view. The applicator 1 comprises three inlets 2, 3, 4 for depositing sealant on to a surface. The applicator comprises an applicator main body 100, which comprises three sealant-contacting surfaces 5, 6, 7 for contacting sealant deposited onto the surface through the inlet as the applicator is moved across said surface. Essentially. sealant is deposited through inlets 2, 3, 4 into a respective inlet reservoir 12, 13, 14 and onto a surface on which a film of sealant is to be formed. Spacers, in the form of projections (some of which are labelled 8a, b, c. 9a, b, c) contact the surface onto which the sealant is deposited and maintain the sealant-contacting surfaces 5, 6, 7 at a predetermined spacing from the surface. The applicator 1 is moved in a forwards motion, shown generally by reference numeral F. This movement causes the sealant-contacting surfaces 5, 6, 7 to move over the sealant deposited through inlets 2, 3, 4, thereby forming a film of sealant, the thickness of the film of sealant being determined by, amongst other things, the spacing between the sealant-contacting surfaces 5, 6, 7 and the surface on which the film of sealant is formed. The applicator 1 comprises three inlet reservoirs 12, 13, 14, each of which receives sealant from a respective inlet 2, 3, 4. Each inlet reservoir 12, 13, 14 is configured to provide a covered space when the applicator is in contact with a surface onto which sealant is to be deposited. The covered space allows the applicator to be used in an inverted orientation, inhibiting loss of sealant from that space. Each inlet reservoir 12, 13, 14 comprises an open face 62, 63, 64 that is, in use, placed proximate the surface onto which sealant is to be deposited. The use of multiple inlets and associated inlet reservoirs facilitates the production of films of different width. For example, by supplying sealant through inlets 2, 3 and 4 a film having a width approximately corresponding to the width of the whole applicator may be deposited. Narrower films may be formed by supplying sealant to any one or two of inlets 2, 3, 4. Furthermore, in the present case, inlet 4 and inlet reservoir 14 are each wider than their respective counterpart inlets 2, 3 and inlet reservoirs 12, 13. This facilitates even greater control of the width of the film deposited using the applicator 1 of the present invention.

[0094] The volume of each inlet reservoir 12, 13, 14 facilitates the storage of a reasonable volume of sealant in the reservoir. This ensures that there is sufficient sealant in a reservoir to help facilitate the deposition of a uniform film, particularly if the applicator 1 is used in an inverted orientation.

[0095] Each inlet reservoir 12, 13, 14 is provided with a respective set 52, 53, 54 of overflow outlets, some of which are labelled 52a, b, d, 53a, b, 54a, b. Each overflow outlet is substantially triangular in cross-section, and is in communication with an outlet flow channel (not shown) that leads from the overflow outlet to a position above an overflow reservoir 55 (best seen in FIG. 2). If excess sealant is delivered to an inlet reservoir, then sealant passes through the respective overflow outlets, through the respective outlet flow channels into the overflow reservoir. The overflow reservoir 55 retains the excess sealant and prevents it from dropping from the applicator when the applicator is used in an inverted orientation, as shown in FIGS. 1 and 2. Each overflow outlet 52a, b, d, 53a, b, 54a, b inhibits unwanted leakage of sealant from the respective inlet reservoir 12, 13, 14, while permitting passage of sealant in the event that the pressure in the inlet reservoir exceeds a certain level. The overflow outlets provide a narrowing in the flow path between an inlet reservoir and the overflow reservoir, inhibiting unwanted leakage from the applicator, while permitting egress of sealant in the event that the pressure in the inlet reservoir becomes too high.

[0096] The overflow reservoir 55 is provided by a trough 56, which is formed by first 56a, second 56b, and third 56c trough walls. The overflow reservoir 55 and hence trough 56 are located towards the front of the applicator and are located forwards of the three inlet reservoirs 12, 13, 14. Trough 56 extends across the width of applicator 1, normal to the direction of intended movement F of the applicator 1 and normal to a longitudinal axis L of applicator 1. First trough wall 56a extends away from the main body 100 of the applicator 1. Second trough wall 56b extends from an end of the first trough wall 56a remote from the main body 100. Third trough wall 56c extends from an end of the second trough wall 56b remote from its attachment to the first trough wall 56a. Third trough wall 56c is relatively short, effectively forming a lip to help retain excess sealant in the trough 56. Referring to FIG. 2, the relatively small height of third trough wall 56c provides a space S that facilitates insertion of nozzles 57, 58, 59 into main body 100 of the applicator. Referring to FIG. 1, a trough end wall 56d is provided on each end of the trough 56 to help retain excess sealant when the applicator is used in an inverted orientation.

[0097] Applicator 1 comprises three nozzles 57, 58, 59 in a unitary nozzle attachment 60. Nozzle attachment 60 is located in a slot provided in applicator main body 100. Each nozzle 57, 58, 59 provides a respective inlet 2, 3, 4 to provide sealant to the applicator 1. Each inlet 2, 3, 4 is slot-shaped and is elongate, and extends across the width of a respective inlet reservoir 12, 13, 14. This arrangement facilitates provision of sealant across substantially the entire width of a reservoir, and facilitates the formation of a film of uniform width. Each nozzle 57, 58, 58 is attached to a separate source of sealant (not shown) and is provided with a separate means of urging the sealant to the respective nozzle. This means that sealant may be delivered separately through the different nozzles, and into the different reservoirs. Partitions 10, 11 are provided between adjacent inlet reservoirs 12, 13, 14. This inhibits movement of sealant between inlet reservoirs and facilitates the deposition of films of well-defined and uniform width. Lateral walls 40, 41 inhibit loss of sealant from the inlet reservoirs, and therefore facilitate the deposition of films of well-defined and uniform widths.

[0098] As mentioned above, applicator 1 comprises three sealant-contact surfaces 5, 6, 7. Each of said sealant-contacting surfaces is provided by a respective baffle 15, 16, 17. Each sealant-contacting surface 5, 6, 7 comprises a curved portion 5a, 6a, 7a that extends to a flat portion 5b, 6b, 7b. The front-most two of those flat portions 5b, 6b are provided with sets 8, 9 of squat projections (some of which are labelled 8a, b, c, 9a, 9b, 9c) for contacting the surface on which the film is to be deposited, and for maintaining the respective sealant-contacting surfaces in spaced relationship with the surface on which the film is to be formed. The squat projections in this case are cuboids, though alternative projection shapes may be used. As the applicator is moved in a forwards direction, a film is formed on the surface of the workpiece. The squat projections cause furrows to be formed in the film, and this may be undesirable, not least because this may cause a film of uneven thickness. Rearmost sealant-contacting surface 7 is smooth and devoid of squat projections, and passage of this rearmost sealant-contacting surface 7 over the furrows formed by the projections projecting from the sealant-contacting surfaces 5, 6 substantially removes said furrows and produces a film of substantially uniform thickness.

[0099] Applicator 1 comprises first 22, second 23 and third 24 sub-spaces between sub-spaces between first 15 and second 16 baffles. The sub-spaces 22, 23, 24 permit the storage of sealant. Furthermore, the width of each of the sub-spaces 22, 23, 24 is essentially the same as that of the corresponding inlet reservoir. The width of first sub-space 22 is essentially the same as that of first inlet reservoir 12, the width of second sub-space 23 is essentially the same as that of second inlet reservoir 13 and the width of third sub-space 24 is essentially the same as that of third inlet reservoir 14. First divider 35 separates first 22 and second 23 sub-spaces. Second divider 36 separates second 23 and third 24 sub-spaces. Applicator 1 also comprises fourth 32, fifth 33 and sixth 34 sub-spaces between sub-spaces between second 16 and third 17 baffles. The sub-spaces 32, 33, 34 permit the storage of sealant. Furthermore, the width of each of the sub-spaces 32. 33, 34 is essentially the same as that of the corresponding inlet reservoir. The width of fourth sub-space 32 is essentially the same as that of first inlet reservoir 12 and first sub-space 22, the width of fifth sub-space 33 is essentially the same as that of second inlet reservoir 13 and second sub-space 23, and the width of sixth sub-space 34 is essentially the same as that of third inlet reservoir 14 and third sub-space 24. Third divider 37 separates fourth 32 and fifth 33 sub-spaces. Fourth divider 38 separates fifth 33 and sixth 34 sub-spaces. The matching of the widths of the sub-spaces with the width of the respective inlet reservoir helps produce sealant films of uniform width.

[0100] The applicator 1 is formed from plastics material and is disposable.

[0101] Nozzle attachment 60 is detachable from the main body 100 of applicator 1 to facilitate cleaning of the nozzles.

[0102] An example of an embodiment of an apparatus in accordance with the third aspect of the present invention will now be described by way of example only. The apparatus is denoted generally by reference numeral 200. The apparatus 200 comprises a line laser sensor 201 for sensing a width of a surface of a workpiece. Briefly, the sensor emits of line of laser radiation onto a surface on to which a film is to be formed. The direction of the line of radiation corresponds to the width of the workpiece. The radiation reflected by the surface depends on the width of the surface; a narrow surface will only reflect a narrow strip of radiation, whereas a wider surface will reflect a wider strip of radiation. This is detected by the sensor, and therefore a width of the surface is sensed. The apparatus 200 comprises an applicator mount 202 for mounting an applicator 1 for forming a film on a surface of a workpiece, such as a vehicle component. In certain embodiments, applicator mount 202 comprises, or is replaced by, a compliant material, such as foam, to facilitate further compliance. While the applicator 1 is shown in FIG. 3, the applicator 1 is not part of the apparatus 200. The applicator mount 202 (and therefore the mounted applicator 1) are moved by means 203 of moving the applicator mount 202 such that an applicator fixed to said mount is movable along a surface of a workpiece. The apparatus 200 comprises a plurality of outlets 204a, b, c for supplying liquid to corresponding liquid inlets provided in the applicator 1. In the present case, outlets 204a, b, c are configured to deliver liquid to the inlets of the applicator 1 via nozzle attachment 60, which is described above in relation to applicator 1. Each of outlets 204a, b, c is coupled to a conduit that is coupled to a respective applicator inlet 2, 3, 4, as described above in relation to FIGS. 1 and 2 so that liquid can be delivered selectively to inlets 2, 3, 4 of the applicator, and therefore different widths of film can be formed on a surface of a workpiece. The apparatus 200 comprises three liquid supply means 205a, b, c for moving liquid from a respective source of liquid 206a, b, c to said outlets 204a, b, c. In the present case, each liquid supply means 205a, b, c comprises a pump for pumping the liquid from the respective source of liquid 206a, b, c to the applicator 1. The apparatus 200 is configured to supply liquid to one or more of the plurality of outlets 204a, b, c dependent on a sensed width of a surface of the workpiece as determined by line sensor 201.

[0103] Applicator mount 202 is in the form of a plate and is configured to securely mount the applicator 1. Applicator mount 202 is coupled to a biasing means 209, which is provided by a Zimmer RP80P compliance unit. The compliance unit may optionally provide an applicator mount in that the applicator may be mounted to the compliance unit without the plate shown in FIG. 3. The biasing means 209 ensures that the applicator 1 maintains contact with the surface of the workpiece at all times, and mitigates against any misalignment of the applicator 1 relative to the workpiece 1. Furthermore, the biasing means 209 ensures that the force between the applicator 1 and workpiece is not excessive. The biasing means 209 may be optimised to ensure constant contact between the applicator 1 and workpiece, without there being too high a contact force that may damage one or both of the applicator 1 and the workpiece.

[0104] The compliance unit is coupled to the L-shaped bracket 208 so that movement of the L-shaped bracket 208 causes movement of the compliance unit. In this connection, motor 207 is configured to move the L-shaped bracket 208 and compliance unit (and therefore the applicator mount 202 and the mounted applicator 1) in a lateral direction (shown by the double headed arrow L in FIG. 3) in order to line-up the applicator mount 202 (and therefore any mounted applicator 1) with a workpiece so that it is in position for deposition. Motor 207 is also configured to move the L-shaped bracket 208 and the compliance unit (and therefore the applicator mount 202 and the mounted applicator 1) in a vertical direction (shown by the double headed arrow labelled V) to move the applicator into, and out of, contact with a workpiece surface.

[0105] Means 203 comprises a motor (not shown) and is used to move not only the applicator mount 202, but all the other components that are directly or indirectly coupled to the applicator mount 202, such as the laser line sensor 201, liquid outlets 204a, b, c. liquid supply means 205a, b, c, sources of liquid 206a, b, c, biasing means 209 and the motor 207 for moving the applicator 1 into lateral alignment with the workpiece and for moving the applicator 1 into contact with said surface.

[0106] Operation of the apparatus 200 and an example of a method 300 according to an embodiment of a second aspect of the present invention will be described with reference to FIGS. 1, 2, 3 and 4, but in particular with reference to FIGS. 3 and 4. A control module 250 is configured to control the operation of apparatus 200. Control module 250 is configured to control operation of laser line sensor 201, liquid supply means 205a, b, c, motor 207 for moving the applicator 1 into lateral alignment with the workpiece and for moving the applicator 1 into contact with said surface and means 203 of moving the applicator mount 202 such that an applicator fixed to said mount is movable along a surface of a workpiece. Operation of the apparatus 200 will now be described. Control module 250 is used to control operation of motor 207 to move the applicator 1 into a starting position and a correct alignment relative to the workpiece. Motor 207 is used to urge the applicator 1 into engagement with the surface of the workpiece. A sensor (not shown) is used to measure the distance to the contact surface onto which the sealant is to be deposited. This distance may then be used to infer a contact force.

[0107] Apparatus 200 is configured to sense 301 the width of a portion of surface of the workpiece in front of the applicator 1. In this connection, the laser line sensor 201 is located forwards of applicator 1, the forwards direction being defined by the intended direction of movement of the applicator 1 as shown by the arrow labelled F. Control means 250 is in communication with laser line sensor 201, and senses a width of a portion of the surface of the workpiece a known distance ahead of the applicator 1. The sensed width of said portion of the surface is used to determine the width of the film that is to be formed on the surface of the workpiece. For example, if the sensed width of said portion of the surface is wide and therefore it is desirable to form a wide film on said portion, control means 250 activates liquid supply means 205a, b, c so that liquid is transferred through liquid outlets 204a, b, c to applicator inlets 2, 3, 4 into applicator reservoirs 12, 13, 14 and deposited 302 onto the workpiece surface. Movement 303 of the applicator 1 in a forwards direction causes sealant-contacting surfaces 5, 6, 7 to pass over the liquid, forming a wide film.

[0108] If the laser line sensor 201 senses 301 a narrowing of the workpiece at a second portion of the surface of the workpiece, then it may be desirable to deposit a narrower film on the surface of the workpiece. As the applicator passes the second portion of the surface of the workpiece, control means 250 activates liquid supply means 205a only that liquid is transferred through liquid outlet 204a only to applicator inlets 2 only into applicator reservoir 12 only, and is deposited 302 onto the surface of the workpiece. Movement 303 of the applicator 1 in a forwards direction causes sealant-contacting surfaces 5, 6, 7 to pass over the liquid, forming a narrow film having a width primarily determined by the width of applicator reservoir 12.

[0109] The apparatus 200 may therefore be used to deposit liquid films of different widths without having to predetermine the shape, size and/or geometry of the surface of the workpiece, and without having to use the predetermined shape, size and/or geometry of the surface of the workpiece to control the movement of the applicator.

[0110] 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.

[0111] The applicator in the examples above is described as having three inlets and three inlet reservoirs to facilitate deposition of films of different widths. Other arrangements are possible. For example, the applicator need not have inlet reservoirs at all. In this connection, the controlled deposition of sealant through any of plurality of inlets may be used to deposit different widths of sealant onto a surface without providing the sealant into an inlet reservoir. That sealant is then transformed into a film by moving the applicator over the sealant. Alternatively or additionally, the rate of supply of sealant to the applicator may define the width of sealant deposited onto a surface, and therefore the width of the film produced from that sealant.

[0112] The examples above illustrate the present invention in relation to the processing and manufacture of workpieces in the form of aircraft components. Those skilled in the art will realise that the present invention may be used with other workpieces.

[0113] The sensors used to sense a width of the surface of the workpiece are line lasers. Those skilled in the art will realise that other sensors may be used.

[0114] The method of forming a film described above uses an applicator. Those skilled in the art would realise that this need not be the case. In the event that an applicator is used in the method of forming a film, it need not be the same applicator as that described above.

[0115] 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.