Multi-Chamber Pack

This invention relates to a multi-chamber pack comprising at least two chambers separated by a frangible partition, externally operable means for breaking the partition, and means for mixing the contents of the two chambers.

Packs of this kind are used more particularly for two-component plastics.

A pack of this kind is disclosed in U.S. Pat. No. 3,153,531, and comprises a cylindrical vessel divided into two chambers by a relatively flat piston. The latter is in the form of a spoked wheel, the spaces between the spokes being closed by a thin membrane or foil and the piston is slideable by way of a piston rod passing through one of the cylinder end walls. In order to mix the contents of the two chambers e.g. resin and curing agent, the membrane closing the openings in the piston is broken by subjecting the piston to an axial load, and then the piston is moved to and fro in the container.

Another two-chamber pack is disclosed in U.S. Pat. No. 3,134,577. This pack has two containers disposed one inside the other to form two axially adjacent cylindrical chambers, and a plate is disposed in one of the chambers extending at right angles to the chamber axis, the plate edge being constructed as a knife edge. The base of the inner container forms the partition between the two chambers. The plate is screwed to a piston rod extending axially through the outer end wall of one of the chambers. To break the partition, the plate is pressed axially against the partition by means of the piston rod and rotated so that the knife-edge forming the edge of the plate cuts through the partition. The contents of the two chambers are mixed in the same way as the pack according to U.S. Pat. No. 3,153,531, by axial reciprocation of the plate by means of the piston rod.

With these known packs it is inevitable that small quantities of the pack contents will pass out through the piston rod and soil the pack, particularly those parts of the piston rod which are situated outside the container. This is highly undesirable for hygienic reasons, particularly in connection with plastics.

The object of this invention is to provide a multichamber pack, more particularly a two-chamber pack, which is of very simple design and accordingly cheap and yet satisfies all labour hygiene requirements. More particularly, the pack will prevent any contact between the skin and the pack contents and prevent fumes escaping.

To this end, according to the invention, the mixing means comprise a rotatable agitator disposed in one of the chambers and a rotatable actuator element disposed on the pack and coupled with the agitator element so as to rotate therewith. The construction of the mixing means as a rotatable agitator element gives a much more effective seal than in the conventional packs so that the pack according to the invention forms a system which is completely sealed off from the exterior and from which the pack contents cannot escape unintentionally.

Preferred embodiments of the invention will be explained in detail hereinafter with reference to the accompanying drawings in which:

FIG. 1 is an axial section through a pack in accordance with this invention, and

FIG. 2 is an axial section through a second form of pack in accordance with this invention.

The pack shown in FIG. 1 comprises two coaxial cups 1 and 2 disposed with their openings facing one another and fixed to one another in sealing-tight relationship by their edges 1a and 2a respectively, but so as to be rotatable in relation to one another about their common axis. A frangible partition in the form of a thin metal or plastic foil 3 is clamped over the opening edge 2a of the top cup 2. This metal or plastic foil 3 divides the interior of the pack into two separate chambers 4 and 5.

Cup 2 has a central recessed end portion 2b with an outwardly curved portion which can be deformed inwardly into the broken-line position when resistance to deformation has been overcome. A coupling sleeve 2c of square cross-section extends axially from the central end zone 2b and its front end extends as far as the metal foil 3 to which it is glued in sealing-tight relationship.

An agitator 6 comprising two perforated vanes 6a and a shaft 6b, is disposed in the bottom cup 1 and is centred by an axial journal 1b extending upwards from the bottom of the cup. The top end of the shaft is ribbed and is positively and operatively held in the coupling sleeve 2c so that the agitator 6 is coupled to the top cup 2 and is rotatable therewwith. The base of the bottom cup 1 also has an outflow aperture 1c and is closed by a welded-on tear-off cover 1d provided with a tab.

The joint between the two cups is covered by an adhesive strip 7 to provide better sealing properties before use and in order to secure the two cups 1 and 2 against unintentional relative rotation. Of course this object could be achieved by other means, e.g. by a tear-off ring or the like formed integrally after the style of the guarantee ring on bottle closures.

For the purposes of mixing the two chamber contents, the adhesive strip 7 is removed and the deformable central end part 2b of the top cup 2 is pressed in which then remains in the deformed position. Consequently, the coupling sleeve 2c moves down and bursts the metal foil 3 so that the contents of the top chamber 5 flow into the bottom chamber 4. The top cup 2 is then rotated in relation to the bottom cup 1 to actuate the agitator 6 therein so that the contents of the two chambers are mixed. When mixing is complete, the tear-off cover 1d is removed and the mixed contents of the pack discharged.

The two-chamber pack shown in FIG. 2 comprises a mixing container 11 in the form of a cup which holds one of the components which are to be mixed together. The second container is formed by an annular cup 13 which is fixed with its open end downwards over a cover 12 which forms a partition between the two containers or reservoirs 11 and 13 and may be made of the same material as that of the partition 3 in the pack described with reference to FIG. 1. The cover 12 has a funnel-shaped recess 14 having a substantially circular frangible line 15 so that the bottom part 16 of the recess 14 can be relatively easily broken in the manner to be described and swung into the position 16 shown in dashed lines.

Container 11 contains an agitator 17 comprising two perforated vanes 17a and a shaft 17b of square cross-section, the agitator being centred by a journal projecting upwards from the base of the container 11. Shaft 17b passes through an opening in the cover 12 and extends through a tubular inner boundary wall 18 of the annular top container 13. A drive member 19 in the form of a cap for the agitator 17 is rotatably mounted on the container 13 and is prevented from being pulled off the container 13 by means of an annular bead 20 on the outer wall of container 13.

The drive member 19 is provided with a coaxial coupling sleeve 21 which engages the agitator shaft 17b and is sealed off from the inner wall 18 of the container 13 by means of sealing lips 22. Coupling sleeve 21 has longitudinal ribs 21a, which project radially inwards and which engage the drive shaft 17b of the agitator or engage therewith on rotation of the cap 19, thus coupling the agitator 17 to the cap 19 so as to rotate therewith.

Opposite the funnel-shaped recess 14, the end wall of the top container 13 has a raised deformable dome 23 which can be pressed by finger pressure inwardly into the broken-line position 23'. A small trough 23a is provided at the topmost point of the dome 23 and co-operates with a cam 19a on the cap 19 to form a resilient detent to secure the cap 19 against unintentional rotation.

A push rod 24 parallel to the container axis is fixed on the inside of the inwardly deformable dome 23 and its bottom end extends nearly as far as the base 16 of the funnel-shaped recess 14 in the cover 12. When the dome 23 is deformed inwardly, the push rod 24 slides down into the position 24' and in so doing breaks the base part 16 along the frangible line 15. In this way the contents of the top container 13 flow into the mixing container 11.

The drive cap 19 has a window 25 which is normally in the position shown. The dome 23 is thus covered with respect to the exterior by the cap 19 so that it cannot be unintentionally deformed. When the contents of the two containers are to be combined, cap 19 must first be turned until the window is exactly above the dome 23. The frangible partition between the two containers can then be broken in the manner described above and the contents of the two containers can be intimately mixed by turning the actuating cap 19. Discharge of the mixed container contents is similar to the embodiment described with reference to FIG. 1, through a opening 27 in the bottom of the mixing container which is closed by a push-in cover 26.

The above-described two-chamber pack can readily be enlarged or modified to form a three-chamber or multi-chamber pack. All that is required is to divide the top container 13 by one or more radial walls into two or more chambers, and provide each such chamber with a deformable wall and a push rod together with a frangible partition.

The multi-chamber pack according to this invention allows handling to be carried out satisfactorily from the working hygiene aspect and is therefore particularly suitable for substances which evolve noxious fumes or with which skin contact must be avoided.