Background of the Invention

1. Field of the Invention

This invention relates to two-compartment containers and in particular to collapsible containers used for holding two materials which can interact with each other.

2. Description of the Related Art

In US-A-4528180 there is disclosed a dental preparation comprising two separately stored dental preparations which are used in combination on expulsion from their respective containers, for example a hydrogen peroxide gel reacts in combination with a paste containing sodium bicarbonate, salt, or other cleansing and polishing agents. These dental preparations are stored in two-compartment containers, which are separated for simultaneous expulsion of the two dental preparations.

One form of construction of two-compartment containers comprises a pair of collapsible tubes which may be arranged side-by-side as in US-A-4528180. Alternatively, one tube may be located within a second tube as is shown in FR-A-2676210.

Summary of the Invention

The present invention relates to a two-compartment container for paste or other thixotropic material which comprises one compartment located within another compartment, and in which the two compartments have separated outlet ports at a common end of the container.

In order to simplify the construction of such tubes, m particular with respect to the expulsion and distribution of the contents, the present invention is characterised m that

the outer compartment has at said common end of the container a nozzle having two side-by-side outlet passageways and in that the outlet port of the inner compartment opens into one of said outlet passageways of the container nozzle.

Preferably the two outlet passageways terminate m two substantially semi-circular shapes and are located side-by- side to form a divided circular orifice to the container.

Nozzles of the two compartments can be formed of a suitable thermoplastics material, such as a composition including high density polyethylene or polypropylene, and the inner nozzle can be made to snap-fit into one outlet passageway of the outer nozzle.

The compartments can be formed from collapsible tube members, preferably made of thermoplastics material, and in particular a thermoplastic laminate comprising a plurality of layers of the same or different thermoplastics materials.

Also according to the invention there is provided a container closure having a lid which is removable from a nozzle to open the container, the lid having on its surface adjacent the nozzle opening a pair of radially spaced annular sidewalls that are concentric with the nozzle and m use seal against the inner and outer surfaces of the nozzle.

Brief Description of the Drawings

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: -

Figure 1 is a cross-section through a nozzle assembly of a container according to the present invention showing the container compartment walls on one side of the centre line only,

Figure 2 is a plan view of the assembly as shown in Figure 1 without the closure 40,

Figure 3 is a plan view of the inner compartment used in the assembly as shown m Figure 1,

Figure 4 is a cross-sectional view through a second nozzle assembly having a modified cap seal, and

Figure 5 is a cross-sectional view through a third assembly having a modified cap.

Descriptxon of the Preferred Embodiments

Now with reference to Figure 1, there is shown m cross- section one end portion of a multi-compartment container 10 for the storage of two different material compositions which are stored separately and which are mixed or put together at the point of delivery from the container Typical materials might be dental preparationε, food pastes, or two-part adhesives

The container 10 comprises an outer compartment 11 formed withm a substantially tubular housing 12, and an inner compartment 13 formed within a substantially smaller diameter tubular housing 14 The inner compartment 13 is eccentric relative to the outer compartment 11 as opposed to being coaxial or concentric thereto

The two tubular housings 12, 14 are preferably formed from flat flexible plastics strip, typically having wall thickness of between 0.2 and 0 5 mm and comprising a laminate of several layers of different plastics materials including a vapour-impermeable barrier which is typically a layer of a plastics material or a layer of aluminium foil The strip is generally formed from high density polyethylene-based materials and the barrier layer is generally based on an ethylene vmyl alcohol material The strip is rolled into a

round or oval shape with overlapping edges of the strip being welded together to form a substantially round/oval cross- section flexible tube, which is subsequently cut to the desired length.

Each tubular housing 12, 14 in use has a closed end (not shown) which is formed with a fish-tail type welded seam as is commonly known in the art The two closed ends may be formed so that each tube 12 or 14 has a respective end closure seam or the two closed ends may be welded together a single welded end closure seam.

The other end of each tubular housing 12 or 14 has a respective shoulder piece 16 or 17 located therein and which has a respective outlet nozzle 18 and 20 therein for expulsion of material from the tubular housings 12, 14 The two shoulder pieces 16 and 17 are moulded from a high density polyethylene compound

The outer tubular housing shoulder piece 16 has a lower cylindrical side wall 19 which is a close fit within an end portion of the outer tubular housing 12 The upper end of the side wall 19 extends mto a rounded edge 21 leading into a frusto-conical shoulder 22 tapering inwardly and upwardly away from the side wall 19 The upper end portion of the tubular housing 12 is then heat formed and welded to the shoulder 22 The radially inner end of the frusto conical shoulder 22 has the outlet nozzle 18 projecting axially therefrom. The nozzle 18 comprises a second cylindrical sidewall 23 coaxial with the first sidewall 19, projectmg coaxially upwardly and terminating at its upper end in a radially inwards projecting shoulder 24. A second frusto-conical portion 26 extends upwardly and inwardly away from the shoulder 24 and terminates in a cylindrical orifice 27 coaxial with the sidewall 23

A substantially diametrical partition 28 extends across both the orifice 27 and the nozzle 18 dividing them mto two passageways 31 and 32 each having a substantially semi-

circular or D-shaped cross-section. The lower portion of the partition 28, on that side which, in use, receives the outlet nozzle 20 of the inner compartment 13, may have a shoulder 29 formed therein.

The inner tubular housing shoulder piece 17 has a substantially D-shaped lower side wall 33 which is a close fit within an end portion of the inner tubular housing 14 which is of a general flexible oval construction. The upper end of the side wall 33 has a rounded edge 34 leading into an inclined shoulder 35. The inclined shoulder 35 slopes inwardly away from the sidewall 33 and extends upwardly to define the outlet nozzle 20 which has a substantially D-shaped cross-section.

The inner tubular housing outlet nozzle 20 is a close fit within outlet passageway 32 and at its inner end abuts the shoulders 29 on the partition 28 and the shoulder 24 on the outer shoulder piece 16. The inner nozzle 20 has a bead 36 which may be a continuous bead or an interrupted bead, on its external surface which engages a like-contoured groove 37 on the inner surface of the outlet passageway 32 to form a snap- fit connection between the inner nozzle 20 and the partition 28 and part of the sidewall 23 of the outer shoulder piece 16.

A closure 40 is fitted over the outer shoulder piece 16 which acts as an external housing for the container 10. The closure 40 comprises a base 41 which is secured to the shoulder piece 16 and a lid or cover 42 which is hinged to the base 41 by a hinge 43 located at one side of the closure.

The base 41 may comprise two parts, an inner annular top portion 49 with a cylindrical wall 44, and an outer annular skirt portion 45 projecting downwardly from the top portion 49. The two parts 49, 44 and 45 may be formed integrally as a single one piece moulding (see Figure 4) , or produced separately and assembled together. The inner wall 44 makes a snap fit connection with the side wall 23 of the outer

nozzle 18 and the outer wall 45 forms an outer decorative skirt. The inner wall 44 has a groove 46 on its inner surface that engages a bead 25, which may be a continuous bead or an interrupted bead, on the outer surface of the side wall 23. The cap 49 has a central aperture 47 through which portions 26 and 27 of the outer nozzle 18 project.

The lid 42 has a central annular side wall 48 which, in use, is concentric with the nozzle orifice 27 and has an annular resilient detent 51 projecting radially inwardly that is engagable with an external bead 52 surrounding the orifice

27 to hold the lid snapped shut over the orifice when the closure is in a closed condition, and which allows the lid to be flipped up to open the container 10 when required.

When the closure is in its open condition and both flexible tubular housings 12 and 14 are subject to pressure to expel their contents, the contents of the inner compartment

13 will be expelled through nozzle 20 and outlet passageway

32 and the contents of the outer compartment 11 will be expelled through passageway 31. The two separated contents will be held apart by the partition 28 but will combine on exiting the orifice 27.

With reference to Figure 4 there is shown a modified container 110 and only the differences, as compared with the first embodiment of the invention, will be described in detail.

The lid 142 included a central portion 143 which may be formed separately and then assembled to the outer portion of the lid 142. The central portion 143 on its side adjacent the nozzle has a pair of radially spaced annular sidewalls 147, 148 that are concentric with the nozzle orifice 127, and a pair of diametrical walls 149 that align with the partition 128.

The sidewalls 147,148 engage the inside and outside

surfaces, respectively, of the nozzle to seal the closure and the diametrical walls 149 engage each side of the partition to seal the passageways 31, 32 from each other.

The inner tube outlet nozzle 120 has an inwardly projecting lip 121 at its outer end to stiffen the nozzle and help prevent retraction after the nozzle has been assembled into the passageway 32 when the discontinuous bead 137 snaps mto cooperating groove 146.

With reference to Figure 5 there is shown a closure 240 m which the cap or lid 242 makes a screw-threaded connection with the outer shoulder piece 216 which is provided with an external screw thread 225 on its cylindrical sidewall 223.

The lid 242 has a top portion 231 and an outer cylindrical sidewall 232. The sidewall 232 has an internal screw thread 233 which co-operates with the thread 225 on the shoulder piece 216 for sealing and opening the passageways 31, 32 The top portion 231 has an annular inner sidewall 248 which seals against the outer surface of the nozzle orifice 227 A circular seal wad 235 is located withm the annular sidewall 248 against the top portion 231.