TECH N ICAL FI E LD

The present invention relates to repair and renovation of building structures, and in particular to a nozzle for syringes that are used to apply filler material to cavities in surfaces of a building structure.

BACKG ROU N D

In a surface of a building structure, such as a wall, a floor, a ceiling or the like, there may be present one or more flaws due to e.g. wear and tear. There may for example be one or more cavities in the form of cracks, holes or other blemishes. A common example of this problem is holes remaining after removal of screws or nails, for example when a painting or other wall-hanging artwork has been taken down or been moved. It is often desirable to repair such flaws and cavities so that the surface of the building structure looks like its new.

A known way of repairing such cavities is by filling the cavity with a filler material, and there are several known devices for filling such cavities, including syringes.

However, known devices and methods for filling cavities with filler material have several drawbacks. For example, it may be difficult to entirely fill the cavity with filler material, and/or to obtain a smooth surface after filling the cavity.

From the above, it is understood that there is room for improvements and the invention aims to solve or at least mitigate the above and other problems.

SU M MARY

The invention is defined by the appended independent claims. Additional features and advantages of the concepts disclosed herein are set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the described technologies. The features and advantages of the concepts may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the described technologies will become more fully apparent from the following description and appended claims, or may be learned by the practice of the disclosed concepts as set forth herein.

In a first aspect there is provided a nozzle for a syringe, the syringe being a syringe for injecting a filler material into a cavity, the nozzle comprising: a nozzle inlet for receiving the filler material from the syringe; a nozzle outlet, in fluid communication with the nozzle inlet, for releasing the filler material into the cavity; a suction means for generating a suction pressure so as to remove air from the cavity through the nozzle outlet; and an actuation means for actuating the suction means.

Preferably, the suction means is a mechanical suction means.

Preferably, the suction means is an expandable volume which, in use, is in fluid communication with the cavity, and wherein the actuation means is means for expanding the expandable volume so as to generate a suction pressure in the expandable volume.

Preferably, the expandable volume comprises: a bottom disc comprising a central opening, an extendable wall section attached to a circumferential portion of the bottom disc in a first end; and a flexible top membrane comprising a central opening, wherein the flexible top membrane is provided with radial stiffeners; wherein the wall section is attached to a circumferential portion of the flexible top membrane in a second end of the wall section opposite to the first end.

Preferably, the flexible top membrane, in an unexpanded state of the expandable volume is substantially parallel to the bottom disc, and the central openings of the top membrane and bottom disc are both substantially aligned with, and in fluid communication with, the nozzle inlet and nozzle outlet.

Preferably, the wall section is extendable in a direction orthogonal to a top membrane facing surface of the bottom disc.

Preferably, the nozzle further comprises a sealing member for creating a seal between the nozzle outlet and a surface surrounding the cavity.

Preferably, the actuation means comprises: a hinge member provided with a slanted surface facing the top membrane, and an inlet cylinder attached to a surface of the top membrane opposite to a bottom disc facing surface, wherein: the inlet cylinder is configured to be pushed against the slanted surface of the hinge member, and the inlet cylinder being moved so as to push against the slanted surface causes an outer portion of the flexible top member to move in a direction opposite to the movement of the inlet cylinder.

Preferably, the inlet cylinder comprises the nozzle inlet in one end and is configured to receive an outlet of the syringe in that end.

Preferably, the hinge member is either: attached to a top membrane facing surface of the bottom disc, or integrated into the bottom disc.

Preferably, the slanted surface of the hinge member is slanting at an angle of between 30 to 45 degrees relative to a top membrane facing surface of the bottom disc.

Preferably, the hinge member comprises air slits for providing an air passage between the nozzle outlet and the expandable volume.

Preferably, the radial stiffeners of the top membrane are thin elongated members provided on one of the main surfaces of the top membrane, or integrated into the top membrane. In a second aspect there is provided an apparatus for filling a cavity, the apparatus comprising: a syringe for injecting a filler material into the cavity; and a nozzle according to the first aspect.

In a third aspect there is provided a method of injecting a filler material into a cavity, the method comprising: attaching a nozzle to a syringe for injecting a filler material into a cavity; placing an outlet of the nozzle over a cavity; actuate suction means of the nozzle; generate, by the suction means, a suction pressure so as to remove air from the cavity; inject, by the syringe and through the nozzle inlet and nozzle outlet, filler material into the cavity.

BRI EF DESCRI PTION OF TH E DRAWI NGS

In order to best describe the manner in which the above-described embodiments are implemented, as well as define other advantages and features of the disclosure, a more particular description is provided below and is illustrated in the appended drawings. Understanding that these drawings depict only exemplary embodiments of the invention and are not therefore to be considered to be limiting in scope, the examples will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: Fig. 1 shows a section of a building structure;

Fig. 2 shows a syringe for applying filler material;

Fig. 3a shows a cavity in a wall surface;

Fig. 3b shows filler material injected into a cavity;

Fig. 3c shows filler material that has been pushed out of a cavity by a compressed air bubble;

Fig. 4 shows a block diagram of a nozzle according to embodiments;

Fig. 5 shows a method of injecting filler material into a cavity according to embodiments;

Figs. 6a-c show exemplary embodiments of a nozzle;

Figs. 7a-b show exploded views of a nozzle according to embodiments;

Fig. 8 shows a top view of each of the components of the nozzle;

Fig. 9a shows an illustrated schematic of a hinge member according to embodiments;

Fig. 9b shows a detail view of a hinge member according to embodiments;

Fig. 9c shows an illustrated schematic of a hinge member according to embodiments;

Fig. 9d shows a detail view of a hinge member according to embodiments;

Fig. 9e shows a sealing member according to embodiments;

Fig. 10a shows a top view of a bottom disc according to embodiments; Fig. 10b shows a side view of a bottom disc according to embodiments;

Figs. 11 a-b show schematic illustrations of a top membrane according to embodiments;

Figs. 11 c-d show top views of a top membrane according to embodiments;

Fig. 12a shows a cross-section of the nozzle in an unexpanded state;

Fig. 12b shows a cross-section of the nozzle in a partially expanded state;

Fig. 12c shows a cross-section of the nozzle in an expanded state;

Fig. 13 shows a method of removing air from a cavity according to embodiments;

Figs. 14a-c show schematic illustrations of a method of filling a cavity according to embodiments;

Fig. 14d shows a cavity filled with filler material by the method of Figs. 14a to 14c;

Fig. 15 shows a flowchart of a method of filling a cavity according to embodiments.

Further, in the figures like reference characters designate like or corresponding elements or parts throughout the several figures. The first digit in the reference character denotes the first figure in which the corresponding element or part appears.

DETAI LED DESCRI PTION

Various embodiments of the disclosed methods and arrangements are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components, configurations, and steps may be used without parting from the spirit and scope of the disclosure.

In the description and claims the words “comprise”, “include”, and variations of the words, such as “comprising” and “comprises”, “including”, “includes”, do not exclude other elements or steps.

Hereinafter, certain embodiments will be described more fully with reference to the accompanying drawings. It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the inventive concept. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice disclosed herein.

The embodiments herein are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept, and that the claims be construed as encompassing all modifications, equivalents and alternatives of the present inventive concept which are apparent to those skilled in the art to which the inventive concept pertains. If nothing else is stated, different embodiments may be combined with each other. Fig. 1 shows a section 101 of a building structure. The building structure may be a wall, a ceiling, a floor or the like. It will be appreciated that the section 101 shown is only a portion of the building structure. The section 101 comprises a surface 102, which may be an interior or exterior surface of the building structure. The surface

102 may for example be an inside wall surface. The surface 102 may be a substantially smooth surface. The surface 102 may be lined (e.g. with wallpaper) or painted.

In the surface 102, one or more cavities 103 may be present. The one or more cavity 103 may be cracks, holes and/or other blemishes. For example, one or more holes may be drilling holes and/or holes remaining after removal of screws or nails, for example when a painting or other wall-hanging artwork has been taken down or been moved. A common method of repairing such cavity 103 is by filling the cavity

103 with a filler material, for example by use of a syringe that can inject the filler material into the cavity 103. The filler material may be a putty material, a surfacing compound material, a spackle material, a plaster material, a resin material, a cement slurry material, or any other material that can be used to fill a cavity 103 in a wall surface. The type of filler material may depend on the type of building structure and/or the type of material from which the building structure and/or surface 102 is made from.

Fig. 2 shows a syringe 201 for applying filler material to a cavity 103 in a wall surface. The syringe 201 comprises a container body 202 for holding the filler material, a syringe outlet 203 through which the filler material can be applied to a cavity 103, and a plunger 204 for pushing the filler material out through the syringe outlet 203 and into the cavity 103.

Although a specific type of syringe 201 is shown in Fig. 2, it will be appreciated that embodiments include the use of all types of syringes. For example, embodiments include the use of syringes that has a different mechanism than a plunger 204 for pushing and/or pressing out the filler material.

However, existing syringes have several drawbacks when used to repair cavity 103 in a surface, as will be described in relation to Fig. 3.

Fig. 3a shows a cavity 103 in a wall surface. The cavity 103 is filled with air, due to being subjected to an environment in which air is present.

As filler material is injected into the cavity 103, a pressure is applied (by the filler material) to the air in the cavity 103. The air in the cavity 103 will thus be compressed and pushed further into the cavity 103 by the filler material. This is illustrated in Fig. 3b. Hence, there is a disadvantage that the filler material cannot fill the entire cavity 103.

Furthermore, upon completion of the filling process, the compressed air in the cavity 103 is no longer under the same enhanced pressure. The air will thus expand and push out some of the filler material out of the cavity 103. This is illustrated in Fig. 3c. It may therefore be difficult to achieve a smooth surface on the wall surface after injecting the filler material. Moreover, if a putty knife or the like is used to smooth the surface, the same problem once again arises, as the smoothing motion of the putty knife will inevitably push some of the filler material back into the cavity 103 thereby again compressing the air trapped therein.

To mitigate the above-described problems, the inventor has provided a nozzle which, before injection of a filler material, removes air in the cavity 103.

Fig. 4 shows a block diagram of a nozzle 401 according to embodiments. The nozzle 401 comprises a nozzle inlet 402, a nozzle outlet 403, a suction means 404, and an actuation means 405. The nozzle 401 may be used together with the syringe 201 , or any other syringe for applying filler material into a cavity 103.

The nozzle 401 may be connectable to the syringe, such that the nozzle 401 can be removed from the syringe. Thus, the nozzle 401 may be sold separately from the syringe. Furthermore, the nozzle 401 may thus be used on several different syringes.

The nozzle 401 may alternatively form an integral part of the syringe. In other words, the nozzle may be permanently attached to the syringe.

In the following figures, a nozzle 401 that is connectable to the syringe will be described, but it will be appreciated that the same structural and functional features would apply to a nozzle forming an integral part of the syringe.

The nozzle inlet 402 is, in use, connected to the syringe outlet 203. As filler material is pushed out of the syringe outlet 203 by use of the plunger 204, the filler material immediately enters the nozzle inlet 402. The nozzle inlet 402 may be adapted to the specific syringe 201 used. For example, the nozzle inlet 402 may be adapted so that the syringe outlet 203 can fit snugly inside the nozzle inlet 402. The nozzle 401 may thus be securely and removably attached to the syringe 201 . Furthermore, the nozzle 401 can be kept in place on the syringe 201 throughout the procedure for filling one or more cavity 103 without being held in place by a user. In embodiments, the nozzle inlet 402 comprises an elastic portion that can be fitted around the outside of the syringe outlet 203. The nozzle 401 can accordingly be used with a variety of syringes 201 irrespective of the diameter of the syringe outlet 203. In embodiments, the inside of the nozzle inlet 402 is provided with a seal so as to ensure the seal between the nozzle inlet 402 and the syringe outlet 203 is airtight. The nozzle outlet 403 is in fluid communication with the nozzle inlet 402 at a first end and, in use, with the cavity 103 at a second end opposite the first end. Filler material can therefore be pushed through the nozzle 401 , by use of the plunger 204, so as to enter the cavity 103. In embodiments, the nozzle 401 comprises a channel with the nozzle inlet 402 at one end and the nozzle outlet 403 at the other end.

The suction means 404 are means for generating a suction pressure (i.e. a reduced or negative pressure). The suction pressure means are fluidly connected to the nozzle outlet 403 and, in use, thereby to the cavity 103. The suction means 404 can thereby remove air from the cavity 103. In embodiment, the suction means 404 generate a suction pressure in a volume in fluid connection to the nozzle outlet 403 (and in turn the cavity 103).

The suction means 404 may be a mechanical suction means, an electrically powered suction means, or other type of suction means capable of generating a suction pressure. Mechanical suction means include for example, mechanical pumps (e.g. hand pumps), and expandable volumes. Electrically powered suction means include, for example, electrically powered pumps.

In embodiments, the suction means 404 is an expandable volume. As the expandable volume expands, air is sucked from the cavity 103 through the suction pressure generated in the expanded expandable volume. The expandable volume may have a volume expansion corresponding to at least the volume of a cavity 103 to be repaired. However, too large a volume expansion may cause the nozzle 401 to be too large to be conveniently used by a user. The volume expansion may preferably correspond to a volume of 10 to 100 ml, more preferably 30 to 70 ml, and most preferably 40 to 60 ml.

The actuation means 405 is a means for actuating (e.g. starting or causing to start) the suction means 404. The actuation means 405 may be a processor configured to initiate the suction means 404 (e.g. a processor for starting an electrical pump), a user interface (e.g. a button or display) for causing a processor to initiate the suction means 404, a mechanical device which can be used to cause initiation of the suction means 404 (e.g. a handle of a hand pump with which the user can initiate the generation of a suction pressure). In embodiments, the actuation means 405 is a means for expanding, or causing to expand, an expandable volume.

Furthermore, the nozzle 401 may preferably comprise a sealing member 406. The sealing member 406 may be located around the nozzle outlet 403 so that the sealing member 406 can form a seal between the wall surface and the nozzle outlet 403. The sealing member 406 thus allows for improved performance of the suction means 404. The sealing member 406 may be made from a relatively soft material, such as rubber and/or silicon. The sealing member 406 can thus conform to the potentially uneven wall surface so as to form a good seal. A thickness of the sealing member 406 may be at least as large as the largest unevenness in the surface. However, as nozzle outlet 403 is displaced from the cavity 103 by the thickness of the sealing member 406, too great a thickness of the sealing member 406 may cause difficulties in injecting the filler material directly into the cavity 103. The thickness may be 0.1 to 5 mm, preferably 0.3 to 3 mm, more preferably 0.5 to 2 mm, and even more preferably 0.5 to 2 mm.

Fig. 5 shows a method of injecting filler material into a cavity 103 according to embodiments.

In step 501 , the nozzle 401 is attached to a syringe 201. In step 503, the attached nozzle 401 is placed over a cavity 103 such that the nozzle outlet 403 covers the cavity 103. Preferably, the sealing member 406 is placed so that is surrounds the cavity 103.

In step 505, the actuation means 405 are actuated so that a suction pressure is generated by the suction means 404. Air is thus removed from the cavity 103. Preferably, the suction pressure is maintained until step 507 is performed, to reduce the risk of air returning to the cavity 103.

In step 507, filler material is injected into the cavity 103 by pushing it through the nozzle 401 using the syringe 201 .

In an embodiment, the nozzle 401 may already be attached to the syringe 201 . Step 501 is accordingly unnecessary and may be neglected. The method of repairing a wall surface may then accordingly comprise steps 503 to 507.

Figs. 6a to 6c show an exemplary embodiment of a nozzle 401 which is attached to a syringe 201 . In this exemplary embodiment, the suction means 404 is an expandable volume 601 . The actuation means 405 are means for expanding the expandable volume 601 . Figs. 6a and 6b show the nozzle 401 in an expanded state (i.e. when the expandable volume 601 is expanded). Fig. 6c shows the nozzle 401 in an unexpanded state (i.e. when the expandable volume 601 is unexpanded).

Fig. 7 shows an exploded view of the nozzle 401. Fig. 7a shows the exploded view of the nozzle 401 when the expandable volume 601 is in its unexpanded state, whereas Fig. 7b shows the corresponding exploded view when the expandable volume 601 is in its expanded state. The nozzle 401 comprises an inlet cylinder 701 , a top membrane 702, a wall section 703, a hinge member 704, a bottom disc 705, and the sealing member 406.

The inlet cylinder 701 forms in an upper end the nozzle inlet 402. The inlet cylinder 701 is preferably made from a rigid material, such as plastic. In embodiments, the inlet cylinder 701 comprises an upper portion, which includes the nozzle inlet 402, which is made from an elastic material. The inlet cylinder 701 is in a lower end attached to an upper side of the top membrane 702.

The top membrane 702 is a substantially flat membrane provided with a central opening. The top membrane 702 is flexible such that a central portion can move relative to a periphery portion in a direction orthogonal to the main surface of the top membrane 702, i.e. along vertical axis A. This movement can be seen by a comparison of Fig. 7a and 7b. The top membrane 702 is provided with radial stiffeners 707. The radial stiffeners 707 ensure a stiffness in the radial direction. The top membrane 702 and the radial stiffeners 707 will be explained in more detail in relation to Fig. 11.

The wall section 703 is formed of a substantially cylindrical member comprising a thin wall. The thin wall is elastic such that it can extend in a longitudinal direction, i.e. along axis A. To achieve this, the thin wall may be made of an elastic material such as rubber. The wall section 703 may be substantially unstressed in a non-extended state such that it retracts back to the non-extended state after expansion. This ensures that the wall section 703 is kept in its non-expanded state when no force is applied. The wall section 703 is attached in an upper end to a lower side of the top membrane 702 and in a lower end to an upper side of the bottom disc 705. The thin wall of the wall section 703 is preferably located at a circumferential position of both the bottom disc 705 and top disc.

The bottom disc 705 is a substantially flat disc provided with a central opening. The bottom disc 705 is preferably rigid such that it does not bend significantly under pressure from the inlet cylinder 701 and/or the wall section 703. The bottom disc 705 is preferably made from a plastic material.

The top membrane 702, wall section 703 and bottom disc 705 are integrally connected to form the expandable volume 601.

The sealing member 406 is a cylinder with a central opening. The sealing member 406 may comprise a substantially flat upper surface facing the bottom disc 705. The sealing member 406 may comprise a substantially flat or round lower surface opposite the surface facing the bottom disc 705. Alternatively, the sealing member 406 may have a circular cross-section. The upper surface of the sealing member 406 is attached to the lower surface of the bottom disc 705. The sealing member 406 is located around the periphery of the nozzle outlet 403.

The hinge member 704 is a cylinder with a central opening. The hinge member 704 comprises a substantially flat lower surface which is attached to the upper surface of the bottom disc 705. The hinge member 704 comprises a slanted surface 708 such that a height of the hinge member 704 is lower in an inner portion (radially) than in an outer portion (radially) of the hinge member 704. An outermost portion (radially) of the hinge member 704 may further preferably comprise a substantially flat upper surface.

The hinge member 704 may be provided with a plurality of air slits 709 through which air can travel in a radial direction from an inner portion of the hinge member 704 to an outside portion of the hinge member 704. The hinge member 704 characteristics will be described further in relation to Figs. 9 and 10.

In various embodiments, at least some of the components of the nozzle 401 are transparent so as to allow the user to see through the nozzle 401 in order to locate the cavity 103, and accurately place the nozzle 401 so as to cover it.

Fig. 8 shows a top view of each of the above-described components of the nozzle 401 . The outer diameter d1 of the top membrane 702, wall section 703, and bottom disc 705 are preferably substantially the same, such that they can form a space-efficient expandable volume 601 where the thin wall of the wall section 703 is located at an outermost or circumferential part of both the top membrane 702 and bottom disc 705. Preferably, the outer diameter d1 is 20 to 200 mm, more preferably 30 to 150 mm, even more preferably 40 to 100 mm, and most preferably 40 to 60 mm. The inner diameter d2 of the central openings of the inlet cylinder 701 , top membrane 702, hinge member 704, bottom disc 705, and sealing member 406 are preferably substantially the same. An inner channel of the nozzle 401 can thus be formed from the nozzle inlet 402 to the nozzle outlet 403. The inner diameter d2 may be dependent on the type of syringe 201 used so as to allow the syringe outlet 203 to be inserted therein. Preferably, the inner diameter d2 is larger than the outer diameter of the syringe outlet 203.

The outer diameter d4 of the slanted portion of the hinge member 704 is at least as great as the outer diameter d3 of the inlet cylinder 701. Thus, the slanted surface 708 of the hinge member 704 completely overlaps the inlet cylinder 701. Preferably, the outer diameter d4 is larger than the outer diameter d3 of the inlet cylinder 701

The outer diameter d7 of the sealing member 406 is preferably at least as large as the outer diameter d3 of the inlet cylinder 701 , and more preferably at least as large as the outer diameter d5 of the hinge member 704. This increases the stability of the nozzle 401 when using the nozzle 401.

A height of the inlet cylinder 701 is preferably sufficiently large to accommodate a significant portion of the syringe outlet 203. This ensures that the nozzle can stay firmly on the syringe outlet during use. Preferably, the height of the inlet cylinder is between 10 to 50 mm, more preferably between 15 to 35 mm, and even more preferably between 20 to 30 mm.

A height of the wall section 703, in its extended state, is preferably between 5 to 20 mm, and more preferably between 10 and 15 mm.

Fig. 9a to 9d show the hinge member 704 according to embodiments. The hinge member 704, as previously described, comprises a plurality of air slits 709. The air slits 709 are openings in the hinge member 704 extending radially from the central opening of the hinge member 704 to an outside portion of the hinge member 704, wherein the outside portion is located in the expandable volume 601. There is thus provided a passage for air from the nozzle outlet 403 to the expandable volume 601.

As shown In Fig. 9a, the air slits 709 may be provided in the slanted portion of the upper surface of the hinge member 704. This allows the air slits 709 to be closed off by the top membrane 702 when the expandable volume 601 is fully expanded.

As shown in Fig. 9c, the air slits 709 may alternatively be provided at least partially below the slanted portion of the upper surface of the hinge member 704, in other words at least partially in the vertical inner section of the hinge member 704. The air slits 709 may, for example be provided at or near the bottom surface of the hinge member 704 (i.e. the surface in contact with the bottom disc 705).

Although eleven air slits 709 are shown in Figs. 9a and 9c, it will be appreciated that fewer or more air slits 709 may be provided. Although rectangular air slits 709 are shown in the illustrations, it will be appreciated that any shape may be used. As shown in Figs. 9b and 9d, which show a cross-section of one half of the hinge member 704, the hinge member 704 has a slanted surface 708 which is slanted at an angle alpha a (alpha). The angle a is preferably between 20 and 60 degrees, and more preferably between 30 and 45 degrees.

Fig. 9e shows a sealing member 406 according to embodiments. Note that not all components of the nozzle 401 are shown. The sealing member, and in turn the nozzle outlet, can be placed so as to surround the cavity in the wall surface 102. Even though the wall surface 102 is uneven, the sealing member 406 ensures an airtight seal between the nozzle and the surface. In the shown embodiment, the sealing member 406 comprises a rounded lower surface facing the wall surface 102.

Figs. 10a and 10b show a top view and side view respectively of an alternative embodiment of the bottom disc 705. In this embodiment, the hinge member 704 is integrated into the bottom disc 705. The slanted surface 708 of the hinge member 704 is thus provided in the portion of the bottom disc 705 closest to the central opening. In this embodiment, the air slits 709 are provided in the bottom disc 705 as well. The characteristics of the integrated hinge member 704 and bottom disc 705 are otherwise substantially identical to the previously described characteristics of each separate component.

Figs. 11 a to 11 d show a top membrane 702 provided with radial stiffeners 707.

As shown in Fig. 11a, the radial stiffeners 707 may be thin elongated ribs. The ribs extend substantially from the central opening of the top membrane 702 to a circumferential portion of the top membrane 702.

As shown in Fig. 11 b, the radial stiffeners 707 may alternatively be integrated into the top membrane 702. This may be achieved by integrating the elongated ribs into the top membrane 702. Alternatively, interspersed portions 707 of the top membrane 702 may be made from a stiffer material than the remaining portions of the top membrane 702.

As shown in Figs. 11c and 11 d, the radial stiffeners 707 may alternatively have a tapered profile such that the thickness of the radial stiffeners 707 increases closer to the central opening. When pressure is applied to the inner portion of the top member, so as to pivot it around the hinge member, the local stress will be greatest close to the pivot point. A tapered radial stiffener thus reduces the maximum local stress experienced at the pivot point and thereby reduces the risk of bending (or breaking) of the radial stiffeners 707.

Although six radial stiffeners 707 are shown in Figs. 11a to 11 d, it will be appreciated that fewer or more radial stiffeners 707 may be provided. The radial stiffeners 707 may be provided at even angular intervals around the top membrane 702. The radial stiffeners 707 may be provided on the upper or lower surface of the top membrane 702. Fig. 12a shows a cross-section of the nozzle 401 in an unexpanded state. In the unexpanded state, the expandable volume 601 is substantially unexpanded. The top membrane 702 is substantially horizontal and rests on an upper surface of the hinge member 704.

Fig. 12b shows a cross-section of the nozzle 401 in a partially expanded state. In the partially expanded state, the expandable volume 601 has partially expanded due to the inlet cylinder 701 being pressed downwards (i.e. towards the hinge member 704). Since the top membrane 702 is provided with radial stiffeners 707, the top member forms a lever pivoted around a hinge of the hinge member 704. Thus, as the innermost portion of the top membrane 702 is pushed down by the inlet cylinder 701 , the outer portion of the top membrane 702 will pivot upwards. The thin wall of the wall section 703 thus starts to extend or stretch which causes the expandable volume 601 to expand. Accordingly, the inlet cylinder 701 together with the hinge member 704 forms the actuation means 405.

Fig. 12c shows a cross-section of the nozzle 401 in an expanded state. In the expanded state the expandable volume 601 has expanded fully due to the inlet cylinder 701 being pushed downwards with a greater force than in the partially expanded state. The wall section 703 is further expanded. The top membrane 702 rests on the slanted surface 708 of the hinge member 704, and can accordingly not be pushed further down by the inlet cylinder 701.

Fig. 13 shows air being removed from the cavity 103 by use of the nozzle 401 according to embodiments. As the inlet cylinder 701 is pressed down against the surface, the top membrane 702 is pivoted around the hinge member 704 causing the expandable volume 601 to expand. A suction pressure is thus generated in the expandable volume 601 causing air in the cavity 103 to flow through the air slits 709 in the hinge member 704 into the expanded expandable volume 601 . Thus, the air initially present in the cavity 103 is at least partially removed. Since, in use, the syringe 201 is attached to the nozzle 401 , no air can enter the cavity 103 through the nozzle inlet 402.

Figs. 14a to 14d shows a method of filling a cavity 103 using the nozzle 401 according to embodiments.

In Fig. 14a, the nozzle 401 , in its unexpanded state, has been attached to the syringe 201 and placed over the cavity 103.

In Fig. 14b, the inlet cylinder 701 is pushed downwards by pushing the syringe 201 towards the surface of the building structure. This causes the expandable volume 601 to expand and air to be sucked out of the cavity 103. The expandable volume 601 is maintained in its expanded state until filler material is injected by maintaining the pressure on the inlet cylinder 701 . In Fig. 14c, filler material is injected into the cavity 103 by pushing the plunger 204 on the syringe 201. The cavity 103 can thus be completely filled with filler material.

As shown in Fig. 14d, the cavity 103 may thus be completely filled with filler material, and a smooth surface can be obtained (without a bulge as in Fig. 3c).

Fig. 15 shows a flowchart of a method filling a cavity 103 using the nozzle 401 according to embodiments. In step 1501 , the nozzle 401 is attached to the syringe 201. In step 1503, the nozzle 401 is placed over the cavity 103. In step 1505, a suction pressure is generated by expanding the expandable volume 601 so as to remove air from the cavity 103. In step 1507, filler material is injected into the cavity 103. The cavity 103 can thus be completely filled with filler material.

Although specific reference has been made to application of filler material to a cavity 103 in a building structure, it should be appreciated that the invention may be used to fill cavity 103 in other structures than building structures.

Throughout this specification, the word “may” is used in a permissive sense (i.e. meaning having the potential to), rather than in the mandatory sense (i.e. meaning must).

As used throughout this specification, the singular forms “a”, “an”, and “the”, include plural referents unless explicitly indicated otherwise. Thus, for example, reference to “an” element includes a combination of two or more elements, notwithstanding use of other terms and phrases for one or more elements, such as “one or more” or “at least one”.

The term “or” is, unless indicated otherwise, non-exclusive, i.e. encompassing both “and” and “or”. For example, the feature “A or B” includes feature “A”, feature “B” and feature “A and B”.

Unless otherwise indicated, statements that one value or action is “based on” and/or “in dependence on” another condition or value or action, encompass both instances in which the condition or value or action is the sole factor and instances where the condition or value or action is one factor among a plurality of factors.

Unless otherwise indicated, statements that “each” instance of some collection have some property should not be read to exclude cases where some otherwise identical or similar members of a larger collection do not have the property, i.e. each does not necessarily mean each and every.