FIELD OF THE INVENTION The present invention relates to cartridges for dispensing fluids. More particularly, but not exclusively, the invention relates to cartridges for dispensing a two part adhesive.

BACKGROUND OF THE INVENTION To prevent leakage and air spoilage, it can be difficult to fill and assemble cartridges for dispensing fluids, particularly in a cost effective manner. Previously, cartridges have been capped at a dispensing end and fluid introduced from a rearward end. With elongate cartridges which use a piston for dispensing the fluids, inserting the piston can be difficult as ventilation is required to evacuate air from between the piston and the fluid. One solution is to provide a piston having a valve, which adds complexity and cost to the cartridge. Another solution is to provide a narrow member along a wall of the cartridge and slide the piston along the narrow member to create a ventilation space. Removal of the narrow member then seals the cartridge, however, damage to the piston and seals commonly occurs. Sealing of cartridges used for two part fluids such as adhesives having a resin and catalyst, for example a masonry anchor cement, can be difficult as highly fluid components of resin and/or catalyst can separate from the adhesive and find a path through the smallest gap between a seal and cartridge wall. As such, it is important that a seal on the piston is optimally placed and not compromised in any way during assembly.

Generally, it is desirable to provide a cartridge that can be quickly and easily filled and which does not leak. It is also desirable to provide a cartridge that is refillable and recyclable.

Examples of the invention seek to solve, or at least ameliorate, one or more disadvantages of previous cartridges.

SUMMARY OF THE INVENTION According to one aspect of the present invention, there is provided a cartridge for dispensing two-part fluids, comprising: a cartridge body having a first fluid reservoir and at least one aperture in a dispensing end of the cartridge body through which fluid can flow for dispensing, and a second fluid reservoir with a dispensing conduit at the dispensing end through which fluid can flow for dispensing; and a nozzle member configured for engagement with the dispensing end and forming a fluid path from the at least one aperture to an outlet disposed in close proximity to an outlet of the dispensing conduit. According to a preferred embodiment of the present invention, the cartridge further comprises a cap configured to close the outlet and the dispensing conduit. Preferably, the cap has an annular portion for sealing the outlet from the first fluid reservoir and a circular portion for sealing the dispensing conduit from the second fluid reservoir, the annular and circular portions being concentric.

The second fluid reservoir is preferably disposed generally within the first reservoir. The reservoirs are preferably concentric.

In a preferred embodiment, the nozzle member forms a chamber or an outer conduit around the dispensing conduit, the conduits terminating in close proximity and forming a dispensing nozzle.

Preferably, the nozzle member is removable to allow filling of the reservoirs from the dispensing end. The nozzle member and cartridge body may be configured for threaded engagement. The nozzle member can have a plurality of lobes formed on an other surface thereof, the lobes configured for engagement to rotate the nozzle member to fix it to the cartridge body.

According to another aspect of the present invention, there is provided a method of filling a cartridge for dispensing fluid, the cartridge having a cartridge body having a first fluid reservoir with at least one aperture in a dispensing end of the cartridge body for dispensing the fluid and a second fluid reservoir with a dispensing conduit at the dispensing end, including the steps of: installing a piston in each reservoir near the dispensing end of the cartridge body; filling the first fluid reservoir with fluid through the at least one aperture and filling the second fluid reservoir with fluid through the dispensing conduit; bringing a nozzle member into engagement with the dispensing end of the cartridge body, the nozzle member forming a fluid path from the at least one aperture to an outlet disposed in close proximity to an outlet of the dispensing conduit; and installing a cap over the outlets to close the cartridge.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be further described, by way of non-limiting example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a cartridge of one embodiment of the invention; Figure 2 is a perspective view of the cartridge with an end cap removed;

Figure 3 is a close perspective view of a dispensing end of the cartridge;

Figure 4 is a side sectional view of the cartridge;

Figure 5 is a close side sectional view of a dispensing end of the cartridge;

Figure 6 is an end view of the cartridge;

Figure 7 is an end view of the cartridge with an end cap removed;

Figure 8 is an end view of a cartridge body; and

Figure 9 is a perspective view of a cartridge body.

DETAILED DESCRIPTION

A cartridge 10 according to a preferred embodiment of the present invention is shown in Figure 1. The cartridge is configured for dispensing two-part fluids, which is the described embodiment is a two-part resin and catalyst adhesive.

The cartridge 10 includes a cartridge body 12 having first and second reservoirs which, in the described embodiment are referred to as a primary fluid reservoir 14 (refer Figure 4) and a secondary fluid reservoir 18. Although the primary fluid reservoir 14 is shown as being of a larger volume than the secondary fluid reservoir 18, it will be appreciated that the volumetric ratio between the reservoirs will vary depending on the product being dispensed and it may be that the reservoirs are of equal volume or that the primary fluid reservoir 14 has a larger volume than the secondary reservoir 18.

The primary fluid reservoir 14 has at least one aperture formed in a dispensing end 26 of the cartridge body and through which the fluid can flow for dispensing. In the illustrated embodiment, two apertures 16a, 16b are provided, though it will be appreciated that a single aperture may be sufficient, as would be 3, 4 or more apertures, depending on the nature of the fluid to be dispensed and the required dispensing performance. In use, fluid flows from the primary fluid reservoir 14, through apertures 16a, 16b under the action of piston 22, which is urged toward a dispensing end 26 of the cartridge.

The secondary fluid reservoir 18 has a dispensing conduit 20 at the dispensing end 26 of the cartridge body and extending therefrom. The conduit 20 is shown as being integral with the secondary fluid reservoir 18, though may be separate from the cartridge body 12 and simply fixed, either removably or permanently, to the cartridge body. In use, fluid flows from the secondary fluid reservoir 18 through dispensing conduit 20 under the action of piston 24 , which is urged toward the dispensing end 26 of the cartridge.

In the illustrated embodiment, the secondary fluid reservoir 18 is disposed within the primary fluid reservoir 14 in a concentric arrangement, though it will be appreciated that the fluid reservoirs may be otherwise arranged. In this regard, the reservoirs may or may not be concentric. Also, they may or may not be coaxial and share a longitudinal axis. Also, the secondary fluid reservoir 18 may be only partly or generally within the primary fluid reservoir 14. Furthermore, the secondary fluid reservoir 18 may be disposed outside of the primary fluid reservoir 14, in an adjacent or side by side arrangement for example.

The illustrated cartridge body 12 is integrally formed with the cartridge body 12 defining the primary and secondary fluid reservoirs 14, 18. The cartridge body 12 is preferably formed of polypropylene, preferably a glass filled polypropylene having 20% glass fill, and formed using conventional injection moulding techniques.

The cartridge 10 also includes a nozzle member 28 configured for engagement with a dispensing end 26 of the cartridge body 12. The nozzle member 28 is in the form of a lid and forms a fluid path from the apertures 16a, 16b to an outlet 30a. The outlet 30a is disposed in close proximity to an outlet 30b of the dispensing conduit 20. In the illustrated embodiment, the outlets 30a, 30b are concentric and the nozzle member 28 forms a chamber or an outer conduit around the dispensing conduit 20, though it will be appreciated that other arrangements are also possible, provided that the outlets terminate in close proximity with each other so as to dispense the fluids from the primary and secondary fluid reservoirs 14, 18 while bringing the fluids into contact with each other so as to promote activation of the resin by the catalyst. The nozzle member 28 may promote mixing, though mixing may also occur outside of the nozzle member, in a hole for example. Although shown as being concentric, the outlets 30a, 30b may be in an adjacent or side by side arrangement, for example.

The nozzle member 28 may also be formed of polypropylene, such as glass filled polypropylene having 20% glass fill for example, and formed using conventional injection moulding techniques .

As illustrated in Figure 9, the dispensing conduit 20 is formed with ribs 21 which assist in locating the nozzle member 28 during assembly and act to maintain separation between the conduit 20 and the nozzle member 28.

In use, a further nozzle (not shown), which may be a conventional nozzle of elongate form, may be fitted to the nozzle member 28. The nozzle provides means for dispensing fluids in narrow openings and may assist in mixing of the fluids. As illustrated in Figure 5, the nozzle member 28 and the cartridge body 12 cooperate to transfer fluid from the primary and secondary fluid reservoirs 14, 18 to outlets 30a, 30b. In some embodiments, the nozzle member 28 and the cartridge body 12 together define fluid paths. In other embodiments, the nozzle member 28 alone may define the fluid paths with the nozzle member 28 forming a dispensing nozzle.

It will be appreciated that the nozzle member 28 may be of a modular design and interchangeable with alternative nozzle members taking different forms depending on the requirements of the application. For example, the nozzle member may incorporate additional functionality or technical features, such as gas operated means for assisting fluid flow. Also, the nozzle member may incorporate a valve or mixing means. Advantageously, the cartridge 10 may have other applications and be used for dispensing different fluids.

The nozzle member 28 and cartridge body 12 may be configured for threaded engagement so as to securely affix the parts together. To facilitate installation, the nozzle member 28 can have a plurality of lobes 42 formed on an other surface thereof. The lobes 42 are configured for engagement to rotate the nozzle member 28 to fix it to the cartridge body 12. Although the nozzle member 28 is shown as having three lobes 42, it will be appreciated that arrangements having 2, 4 or more lobes may also be provided. By providing the nozzle member 28 and cartridge body 12 in threaded engagement, the nozzle member 28 may be removable to allow refilling. In other embodiments, the nozzle member 28 may be permanently fixed or bonded to the cartridge body 12.

The cartridge 10 further comprises a cap 32 configured to close the outlets 30a, 30b. In the illustrated embodiment, the cap 32 is in threaded engagement with the nozzle member 28, though it will be appreciated that it may be affixed by other means, such as a tight or tapered fit using friction for retention, for example. To close the outlets 30a, 30b the cap has respective portions for sealing each of outlets 30a, 30b. In this regard, the cap 32 has an annular portion 34 for sealing the outlet 30a from the primary fluid reservoir 14 and a circular portion 36 for sealing the outlet 30b from the secondary fluid reservoir 18. Owing to the nature of the outlets 30a, 30b, the annular and circular portions 34, 36 are concentric, though in other embodiments they will be otherwise arranged to be complimentary with the outlets 30a, 30b.

To prevent or at least reduce leakage from outlets 30a, 30b, seals are provided within the cap. In this regard, the cap 32 includes seals 38a, 38b for sealing the outlet 30a. The cap also includes seal 40 for sealing outlet 30b. The seals 38a, 38b and 40 are preferably formed with a narrowed wall thickness so as to be flexible yet retain sufficient rigidity to maintain a seal, and dimensioned so as to be tightly fitting or in a slight interference fit with the conduit 20 and nozzle member 28. As described above, the nozzle member 28 is configured for engagement with a dispensing end 26 of the cartridge body 12. By providing a nozzle member 28 as a separate part, the cartridge 10, in particular the reservoirs 14, 18, may be filled from the dispensing end 26. Furthermore, by providing the nozzle member 28 as a separate part, manufacturing is simplified and a favourable tool draw is obtained that allows prominent markings to be formed on an outer surface. This can improve aesthetics and allow prominent branding to be displayed. Filling of the cartridge 10 is performed by installing pistons 22, 24 into the cartridge body 12. The pistons 22, 24 are advanced toward the dispensing end 26. By filling the primary and secondary fluid reservoirs 14, 18 under pressure, the pistons 22, 24 are pushed into an in use position away from the dispensing end. Advantageously, as the pistons pass over a clean surface, leakage may be avoided. The primary fluid reservoir 14 is filled with a resin, preferably an epoxy resin, through apertures 16a, 16b using an apparatus having nozzles which are correspondingly shaped with the apertures 16a, 16b so as to prevent leakage. The secondary fluid reservoir 18 is filled with a catalyst or hardener through conduit 20. A filling machine (not shown) may be provided for simultaneous filling. The filling machine may contain a supply of resin stored separately from a catalyst and have respective nozzles for engagement with the apertures 16a, 16b and conduit 20.

Once the respective primary and secondary reservoirs 14, 18 have been filled with resin and catalyst, the nozzle member 28 is installed to form a fluid path from the aperture 16a, 16b to outlet 30a, thereby providing a dispensing nozzle for the fluids. Once filling is complete and the nozzle member 28 installed, the pistons may be advanced to remove air from the cartridge. Finally, cap 32 is installed over the outlets 30a, 30b to close the cartridge.

Compared with previous filling methods, the described cartridge allows conventional pistons to be used yet provides an improved seal that has the potential to minimise leakage.

The embodiments have been described by way of example only and modifications are possible within the scope of the invention disclosed.