Multi-cavity dispensing refill cartridge

Abstract: A multi-cavity dispensing refill cartridge is provided, to be used with a reusable base. The refill cartridge has two hollow, separate parallel cylinders for containing flowable material. The cylinders have a first generally closed end and a second end which accommodates piston heads and outlet means. The piston heads are compressably engageable with piston rods of the reusable base. Relative compression of the piston heads and cylinders cause flowable material to flow toward the first end of the cylinders and out the outlet means. The outlet means include means for causing the flowable materials to flow toward each other at the outlet opening. The refill cartridge is provides with means for selectively, engaging the reusable base.

Description: The present invention relates to rigid telescopically arranged multi-cavity dispensing containers for flowable material, such as tooth paste and the like, from which it is desired to dispense simultaneously two or more reactive substances which require separate storage until time of use. More particularly it relates to a disposable refill cartridge for use in a dispensing container of the above type which can be used in conjunction with a reusable base. There exists a desire to provide sodium bicarbonate and peroxide gel as components of toothpaste. Sodium bicarbonate is a well known and commonly used abrasive and cleaner. Peroxide gel is regarded as a beneficial ingredient to help promote healthy gums. These components are reactive when mixed, and therefore must be maintained separately until time of use. U.S Pat. Nos. 5,020,694 to Pettengill and U.S. Patent No. 5,038,963, to Pettengill and Gentile, which are hereby incorporated by reference, disclose rigid piston type multi-cavity dispensing containers for the simultaneous coextrusion in predetermined proportions of two or more materials which may have different rheologies. The lower body members have a base and two or more pistons attached thereto. The upper body members have parallel cylinders for containing the flowable materials, and outlet means for dispensing the materials. The lower end of the cylinders receive the pistons whereby the relative compression of upper and lower body members forces the flowable materials out through the outlet means. This produces a single, banded unmixed stream of material that can be neatly and easily applied onto the narrow width of a toothbrush. The upper and lower members cannot be sold as separate independent units, because the piston heads which are attached to the lower member are needed to seal the flowable material within the upper member. In addition, ridges formed on both the upper and lower body members prevent them from being pulled apart. Thus both upper and lower body members must be discarded after the contents of dispenser are used up. This produces unnecessary waste and is not the most economical of arrangements. EP-A-0294672 describes a double delivery dispenser cartridge for two-component substances. In order to dispense the substances, it is necessary to place the cartridge in a dispensing device which comprises two parallel rams which move against pistons in the cartridge. However, no reference is made to means for detachably mounting the cartridge on a base unit so that the cartridge can be permanently mounted on the base unit until the contents are completely discharged. According to the invention, there is provided a multi-cavity dispensing refill cartridge, for use with a reusable base unit, for the coextrusion of at least two flowable materials as defined in claim 1. Claims 2 to 12 refer to preferred embodiments of the cartridge of claim 1. Claim 13 defines a toothpaste dispensing system with a cartridge according to the invention. By "selectively engagable" in this application, it is meant that the cartridge has a means which is part of the cartridge and is capable of engaging a part of the reusable base so as to prevent their separation when they are pulled apart, but which are operable so as to allow the refill cartridge to be removed from the usable base when empty. A first catching ridge formed on the refill cartridge may engage another catching ridge on the reusable base to prevent the unintended separation of the refill cartridge from the reusable base. The first catching ridge may be located on a flexible portion of the refill cartridge so that the two catching ridges may be pressed apart to allow separation of the refill cartridge from the reusable base. The cylinders may be incorporated in a shroud designed to conform with a shroud of the reusable base. In addition, the conforming shrouds may include corresponding longitudinal axial grooves and ridges for linearly guiding axial movement between the refill cartridge and the reusable base. In a preferred arrangement, the shroud of the refill cartridge fits within the shroud of the reusable base and the catching ridge of the refill cartridge is located on-a longitudinal axial ridge of the refill cartridge, and the catching ridge of the reusable base is located on a longitudinal groove of the reusable base. In addition, in this preferred arrangement, the catching ridge of the refill cartridge has adjacent slots so that catching ridge can be pushed inward to allow the refill cartridge to be pulled apart from the reusable base. In the context of the invention, the refill container seletively engages the reusable base unit; by that is meant that the selectively engaging means can retain the integrity of the container such that the upper shroud does not disengage the lower shower unless it is required to. However, when desired, the selectively engaging means can be operated to allow the refill cartridge to be pulled apart from the reusable base, and replaced with a full cartridge. The invention will now be further described by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is an exploded view of a multi-cavity dispensing refill cartridge and a reusable base to be used in conjunction therewith. Fig. 2 is a sectional view of the Fig. 1 upper shroud taken through the outlet channels. Fig. 3 is a frontal cutaway view of the Fig. 1 refill cartridge. Fig. 4 is a side view of a refill cartridge and reusable base having front and back guide means. Fig. 5 is a frontal cutaway view of a refill cartridge mounted on a reusable base. Figs. 6a and 6b are respectively a sectional side view and a bottom view of a piston head. Fig. 7 is a perspective view of an outlet assembly. Fig. 8 is a sectional view of an outlet assembly. Fig. 9 is a frontal view of a nozzle with an opened, hinged cap. Fig. 10 is a sectional view from the side of the Fig. 9 nozzle. Fig. 11 is a sectional view from the side of a reusable lower body. Fig. 12 is a perspective view of a refill cartridge with a window. Fig. 13 is an alternate two piece outlet assembly. Fig. 14 is a cross-sectional view of the Fig. 13 outlet assembly. Fig. 15 is an enlarged interior end view of the nozzle member of the outlet of Fig. 13. An exploded view of a multi-cavity dispensing refill cartridge 1 and a reusable multifunction base 2, to be used in conjunction therewith, is shown in Fig. 1. The refill dispensing cartridge 1 has a upper shroud 3 which incorporates two hollow, separate, parallel cylinders which each contain one of two reactive flowable materials. Two cylindrical outlet channels 12 provide fluid communication between the cylinders and outlet assembly 5. Hinged cap 34 seals the outlet assembly 5. A sectional view of the Fig. 1 shroud 3, taken through the centre of the outlet channels 12, showing the two parallel cylinders 6, and their communication with the outlet channels 12, is shown in Fig. 2. The multifunction base 2 to which the parallel cylinders 6 are attached allows the device to stand upright, and also provides leverage for the device when the cartridge 1 is pressed by a user, facilitating single handed usage and dispensing from the device. Multifunction base 2 additionally rigidly retains parallel piston rods 8 so as to provide for the smooth, equal and simultaneous movement of piston heads 4 into the cylinders 6 during operation. Referring back to Fig. 1, the top end 41 of each cylinder is generally closed except for the outlet channels 12. The bottom end 42 of each cylinder is sealed by a piston head. Thus the flowable materials are completely sealed within the refill cartridge allowing it to be handled and sold as a unit separate and independent from the reusable base 2. Referring to Fig. 3, which is a frontal cutaway view of a refill cartridge, it can be seen that each cylinder 6 telescopically and slidingly accommodates a piston head 4 which conforms to ride sealingly within the inner walls 7 of the cylinders 6. Each piston head 4 has a central portion 11 designed to be received by openings in piston rods of the reusable base. Referring back to Fig. 1 it can be seen that the reusable base 2 has a pair of parallel piston rods 8, with openings 10 designed to surround the lower portion 11 of the piston heads 4. The openings 10 are dimensioned such that central portion 11 can easily slide into and out of them. This makes the piston heads 4, which are initially located in refill cartridge 1, compressibly engageable with piston rods 8. In other words, when the refill cartridge 1 and the reusable base 2 are compressed together, edge 47 of the piston rods 8 abuts and presses upon the bottom portion 48 of piston heads 4 as shown in Fig. 5. Referring to Figs. 6a and 6b, which are respectively a sectional view from the side and bottom view of a piston head 4, it can be seen that bottom portion 48 of the piston head 4 is the bottom edges of ribs 74 which extend between the cap portion 76 of piston head 4 and central portion 11. In addition to providing a surface for edges 47 of the piston rods 8 to press against, ribs 74 also contribute to the structural stiffness of the piston heads 4. When the refill cartridge and the reusable base are pulled apart, central portions 11 of the piston heads 4 slide easily out of openings 10. Thus the piston heads 4 only engage the piston rods 8 when refill cartridge 1 and reusable base 2 are compressed. As shown in Fig. 1, reusable base 2 is dimensioned to telescopically receive refill cartridge 1. Specifically, upper shroud 3 is arranged to closely conform in sliding relation with lower shroud 9. The upper and lower shrouds 3 and 9 include means for guiding linear motion between the refill cartridge 1 and reusable base 2, shown as conforming longitudinal projecting ridges 51 and 52. These ridges are longitudinal, outward, rectangular extensions of the shrouds 3 and 9 having parallel side walls and flat facing surfaces. The projecting ridge 52 of the lower shroud 9, which forms an inner groove 55, is dimensioned to receive longitudinal ridge 51 of the upper shroud 3. When the two shrouds are assembled and compressed the longitudinal ridges 51 and 52 serve to guide the relative motion of the refill cartridge and the reusable base, preventing their relative rocking and providing smooth, equal, linear motion of the piston heads even where the materials in the two cylinders have different rheologies. The shrouds 3 and 9 may be provided with longitudinal projecting ridges on both their front and back sides. These are shown as 51a, 51b, 52a, 52b in Fig. 4. In addition, front ridges 51a and 52a may have different widths then back ridges 51b and 52b. These then serve to orient the reusable base with respect to the refill cartridge. This is especially useful when the refill cartridge is to be used with a reusable base which has an extension such as extension 57 designed to prevent the forward tipping of the reusable base 2 and refill cartridge 1 when downward pressure is applied to the refill cartridge 1. It is understood that the means for guiding linear motion between the refill cartridge and the reusable base may be of any acceptable shape and comprise a plurality of extensions, both inward and outward. In addition to providing guided relative motion of the shrouds, the extensions improve the mechanical rigidity of the shrouds. Referring to Fig. 5, when refill cartridge 1 and the reusable base 2 are compressed, piston rods 8 simultaneously and equally push upwards the piston heads 4 thereby forcing the flowable reactive materials upwards and into the outlet channels 12 and through outlet assembly 5. Flowable materials from each of the outlet channels 12 is received by outlet assembly 5, shown in Figs. 7 and 8, which provides for a forward facing dispensing nozzle. Outlet assembly 5 is fitted about outlet channels 12 and converges so as to end in an outlet passage 14. Outlet passage 14 has two passageways 15, each of which connects through one of the outlet channels 12 to one of the two cylinders 6. The outlet passage 14 of outlet assembly 5 is arranged to receive a separate nozzle 16, which together comprise the outlet means 17 as shown in Fig. 1. The outlet channels 12 receive sleeves 18 of the out assembly 5 shown in Figs. 7 and 8. As the tube sleeves 18 converge, they form a common rigid barrier 19. The outlet passage 14 is bisected by a flat rigid septum 20 extending from the barrier 19, sitting fixedly within the inner walls of the outlet passage 14 and projecting therefrom. The septum 20 is tapered cross-sectionally and ends in a straight edge 22. The cross-section of the septum edge 22 is a sharp angle approximated by a very small radius. The sides of the septum are preferably textured, for example by vapour honing,to a dull finish to promote adherence of the products thereto, which together with the taper causes the product streams to converge into a single stream as they emerge from adjacent outlet openings 23 shown in Fig. 9. The septum 20 acts to keep the two reactive materials separate as they emerge from the cylinders 6 and also prevents reaction and obstruction of the outlet means 17 by reaction products. The flowable materials converge as they flow through the outlet means 17 but the two streams do not meet until they have fully left the outlet means opening 23. The taper design of the septum 20 causes the two streams to gradually converge until they meet at the septum edge 22 beyond the end of the outlet means opening 23. At this point they smoothly touch and continue to flow onto the intended surface, e.g. toothbrush, as a single, substantially cylindrical, banded stream. This stream is convenient and easy to direct with accuracy upon a limited surface area. The diameter of the emerging stream may be regulated according to the packaging specifications. For example, nozzle 16, shown in Figs. 1, 9 and 10, which snaps on around the outlet passage 14 by engaging ridge 38 may have an interior taper which reduces the effective outlet passage diameter as shown in Fig. 10. In such an embodiment, the length of the septum edge 22 may be reduced and the side edges of the septum conform to the converging inner shape 35 of the nozzle 16. With reference to Fig. 9, nozzle 16 is provided with longitudinal grooves 37 along its converging inner wall for retaining the inward sloping sides of the septum 20 residing therein. Such an arrangement maintains the septum 20 within a rigid position within the outlet means 17 and prevents intermixing of the streams at contact points of the assembled septum 20 and outlet means 17. The septum 20 extends to a location preferably 0.005 to 0.010 inches beyond the outlet means opening 23. The nozzle 16 preferably has a cap 34 connected thereto by a hinge 33. Cap 34 includes a complimentary, engaging means comprising recesses 31a and 22a for receiving respectively nozzle rim 31 and septum edge 22 during closure, so that intermixing of the two substances is prevented once the cap is closed. The outlet means 17 is provided with one or more means for causing the outlet streams to flow toward each other and avoid the otherwise uncontrolled outlet flow which can result in the streams of the two or more materials flowing away from each other as they emerge from the outlet opening. The means may include a tapered septum 20 which divides the outlet, tapered peripheral walls on the outlet means as exemplified by nozzle 16, a differential surface resistance on the interior walls of the outlet means, such that greater surface resistance is provided on the interior surfaces which are adjacent to other outlet openings than on the peripheral interior surfaces of the outlet means, or any combination of these features. Thus the surfaces of the septum 20 may be provided with a dull finish, such as by vapour honing, while the interior peripheral surfaces of nozzle 16 remain smooth. As the materials flow over the surfaces there will be greater assistance to the flow over the septum, tending to cause the flow of materials to "curl" in the direction of the septum as they emerge from the outlet, whereby the two or more streams of material curl towards each other and converge into a single stream. Alternatively, the interior peripheral surfaces of the outlet means can be treated, e.g. with a lubricant, such as polytetrafluoroethylene or silicone materials to reduce the surface friction of the interior peripheral surfaces as compared to the surface friction of the septum 20. Referring once again to Fig. 1, it can be seen that means for selectively engaging reusable base 2, shown as horizontally extending catching ridge 61, protrudes outward from the longitudinal extending ridge 51 on the front side of upper shroud 3. This ridge is used to keep the upper shroud 3 from disengaging from the lower shroud 9 when the dispenser is lifted by the upper shroud 3. As shown in Fig. 11, a corresponding catching rib 62 projects inward from the inside groove 55 of longitudinal extending ridge 52a of lower shroud 9. The two catching ridges engage when the upper and lower shrouds are pulled apart so as to prevent their separation. Referring back to Fig. 1, it can be seen that two vertically oriented slots 65 may be formed on either side of catching ridge 61. This makes the area around catching ridge 61 relatively flexible such that when the area 64 above it is pressed upon by a thumb or finger, catching ridge 61 moves inward sufficiently so that it will not engage with catching ridge 62 when refill cartridge 1 is pulled apart from reusable base 2. This allows the refill cartridge to be removed from the reusable base when it has been emptied so that it may be replaced with a full cartridge. As an alternative to the vertical slots 65, the area around the catching ridge 61 may be made sufficiently flexible by making it thinner than the rest of the upper shroud 3. As an alternative to the catching ridge 61, upper shroud 3 may be provided with a window 68 as shown in Fig. 12. In this embodiment the lower edge 69 of the windows serves as a means for selectively engaging the reusable base 2 via catching ridge 62. Once again vertical slots 65 on either side of the window 68 make the area relatively flexible such that when area 64 is pressed upon by a thumb or finger, the lower edge 69 moves inward sufficiently so that it will not engage the catching ridge 62 when refill cartridge 1 is pulled apart from reusable base 2. The upper edge 70 of the window is bevelled so that it does not prevent the relative compression of the refill cartridge 1 and the reusable base 2. A preferred embodiment of outlet assembly 5 is shown in Figs. 13, 14 and 15. Outlet assembly 5, as shown in Figs. 7 and 8, includes a projecting thin septum 20, which may pose difficulties in fabrication. In the alternate embodiment of Figs. 13 through 15 the outlet assembly 5 is fabricated of connecting part 242 and nozzle member 252, and the use of a thin projecting septum is eliminated. Connecting part 242 includes a housing arrangement similar to that of part 5 which engages projecting outlets 12 of the refill cartridge and includes sleeves 241 which have internal passages 254 and 256. A cylindrical extension 244 of connecting part 242 includes an interior septum 262 extending to the forward end thereof and separating internal outlet passages 258 and 260 which are respectively connected to inlet passages 254 and 256. A separate nozzle member 252 is arranged to snap fit over cylindrical extension 244 of connecting part 242. To facilitate the snap fit in an appropriate rotational orientation, cylindrical extension 244 is provided with an engaging rib 246 and triangular shaped locating protrusions 250. Nozzle member 252 has a recess portion 264 with an interior rib 266, shown in Fig. 14 which is engaged by rib 246. As shown in Fig. 15 interior rib 266 only extends partially around the peripheral nozzle member 252 whereby gaps are formed to receive triangular locating ridge 250 to assure appropriate angular orientation of nozzle member 252 when is fitted over extension 244. Nozzle member 252 includes a nozzle portion 269, which is circular in cross-section and includes septum 270 which bifurcates nozzle 269 into channels 272 and 274. Septum 270 is preferably tapered and textured as described above and extends to the outlet opening of nozzle member 252. The interior ends of channels 272 and 274 within recess 264 include projecting ribs 276 which form grooves 280 and 278 for receiving respectively the edges of the peripheral walls of extension 244 and septum 262. Tapered ridges 268 on the interior wall of recess 264 are arranged to press the peripheral edges of extension 244 of member 242 into close fit with ridges 276. In an exemplary embodiment four such tapered ridges are provided at equal spacing around recess 264. Nozzle member 252 is provided with a snap fit cap pivotally mounted thereto having a configuration similar to cap 34. When assembled, the peripheral edges of channels 258 and 260 are guided into the proper orientation of grooves 280 and 278 by triangular ridges 250 acting in conjunction with interior ridges 266. When fully inserted ridge 266 snaps behind ridge 240 and the forward edges of extension 244 are pressed close to projections 276 by ribs 268, forming a close fit between outlet passages 258 and 260 of connecting 242 and passages 272 and 274 of nozzle member 252.

Claims: A multi-cavity dispensing refill cartridge (1), for use with a reusable base unit (2), for the coextrusion of at least two flowable materials, the cartridge comprising: at least two hollow and separate parallel cylinders, each cylinder for containing one of the flowable materials, the cylinders having a first generally closed end (41) and a second end (42) telescopically and slidingly accommodating at least two parallel piston heads (4) which conform to ride sealingly along the interior walls of the cylinders so as to force the flowable materials to flow towards the first end (41) of the cylinders upon relative compression of the cylinders and piston heads (4), the piston heads (4) being engageable with piston rods (8) of a reusable base unit (2), the cylinders having outlet channels (12) at the closed end; and an outlet means (17) in fluid communication with the outlet channels (12), the outlet means (17) including adjacent outlet openings (23) unconnected to each other and having means (20) for causing the flowable materials to flow towards each other at the outlet openings (23) to form a single banded, unmixed stream of the materials outside of the outlet means (17), characterised in that the piston heads (4) are compressibly engageable with the piston rods (8), and in that the refill cartridge (1) further comprises means (61) for selectively engaging the reusable base unit (2) such that the refill cartridge (1) is removable from the reusable base unit (2) when said cartridge (1) has been emptied. A multi-cavity dispensing refill cartridge (1) according to claim 1 wherein the cylinders are incorporated within an upper shroud (3), the upper shroud (3) being arranged to closely conform in sliding relation with a lower shroud (9) of a reusable base unit (2), whereby relative motion between the shrouds (3,9) is constrained to be substantially linear providing equal linear motions of the piston heads (4) into the cylinders. A multi-cavity dispensing refill cartridge (1) according to claim 1 or claim 2 wherein the means (61) for selectively engaging the reusable base unit (2) comprises a horizontally extending first catching ridge (61) formed on the upper shroud (3), the horizontally extending first catching ridge (61) being sized to engage a horizontally extending second catching ridge (62) formed on a lower shroud (9) of a reusable base (2). A multi-cavity dispensing cartridge (1) according to claim 3 wherein the upper shroud (3) is arranged to closely conform in sliding relation within a lower shroud (9) and wherein the horizontally extending first catching ridge (61) protrudes outward from a relatively flexible portion (64) of the upper shroud (3) so as to be selectively engageable with an inwardly projecting, horizontally extending second catching ridge (62) formed on the inside of the lower shroud (9) whereby when an area (64) above the first catching ridge is pressed upon by a thumb or by a finger, the first catch ridge (61) moves sufficiently inward so that it will not engage the second catching ridge (62) when the refill cartridge (1) is pulled apart from the reusable base (2). A multi-cavity dispenser (1) according to any of claims 2-4 characterised in that it further comprises means (51,52) for guiding linear motion between the refill cartridge (1) and a reusable base (2). A multi-cavity dispensing refill cartridge (1) according to claim 5 wherein the means (51,52) for guiding linear motion between the refill cartridge (1) and a reusable base (2) comprise a longitudinal projecting ridge (51) in the upper shroud (3) which conforms to an inner groove (52) of a lower shroud (9) for guiding the linear notion. A multi-cavity dispensing refill cartridge according to claim 6 wherein the horizontally extending first catching ridge (61) is formed on a longitudinal projecting ridge (51) of the upper shroud (3) so as to be selectively engageable with the horizontally extending second catching ridge (62) formed on the inner groove (52) of a lower shroud (9). A multi-cavity dispensing refill cartridge (1) according to claim 6 or claim 7 wherein the upper shroud (3) has two longitudinal projecting ridges (51a,51b) of different widths whereby two the longitudinal projecting ridges (51a,51b) serve to properly orient the dispensing refill cartridge (1) in the reusable base unit (2) having two corresponding inner grooves (52a,52b) of appropriate widths. A multi-cavity dispensing refill cartridge (1) according to any of claims 3-8 wherein the upper shroud (3) defines vertically oriented slots (65) on either side of the horizontally extending first catching ridge (61). A multi-cavity dispensing refill cartridge (1) according to any of claim 4-9 wherein the relatively flexible portion (64) of the first shroud (3) is thinner than the rest of the upper shroud (3). A multi-cavity dispensing refill cartridge (1) according to claim any of claims 3-10 wherein the horizontally extending first catching ridge (61) is formed on a front side of the refill cartridge (1). A multi-cavity dispensing cartridge (1) according to any of claims 1-11 wherein the means for selectively engaging a reusable base unit (2) comprises a window (68) having a lower edge (69) formed in a relatively flexible portion of the upper shroud (3) so as to be selectively engageable with a catching ridge (62) formed on the lower shroud (9) whereby when an area (64) above the window (68) is pressed on by a thumb or a finger, the window (68) moves so that it will not engage the catching ridge (62) formed on the lower shroud (9). A toothpaste dispensing system characterised in that it comprises a multi-cavity dispensing refill cartridge (1) according to any of the preceding claims, in conjunction with a reusable base (2).

Inventors: GENTILE JAMES LOUIS, GENTILE, JAMES LOUIS
Applicants: UNILEVER NV, UNILEVER PLC, UNILEVER N.V.
Application year: 1993
Main classification: B65D81
IPC codes: B65D83, B65D81