AU651815B2 - An improved soap cake - Google Patents

Description

WO 91/13970 PCT/AU91/00079 1 AN IMPROVED SOAP CAKE This invention relates to improvements in and to a soap cake.

In using cakes of toilet soap for example, it is well known that considerable annoyance and wastage occurs when the soap cake is worn beyond a practicable manageable size. The soap becomes thin and fragile and in turn difficult to hold and apply to the body, eventually breaking into even smaller fragments or portions. These smaller fragments or portions normally find their way into drain outlets and are difficult if not impossible to remove. It is also common place for people to discard the soap cake after it has reduced to an unmanageable holding size which again represents significant wastage of the product.

It is an object of the present invention td obviate the aforementioned problems by providing a soap cake that eliminates wastage by the end user.

It is a further object of the present invention to provide an improved soap cake which is designed so that it will always be in a size convenient to a user for holding and handling and which will allow the soap cake to be entirely consumed.

In its simplest form therefore, this invention is directed to an improved soap cake having in one of its major surfaces a recess shaped and dimensioned so as to be able to receive therein an implant of a smaller worn or used soap cake, said recess being provided with means for assisting the retention of the implant therein, whereby the implant, when so received, becomes integrated with the host cake.

Preferably the surface of the recess is provided with a plurality of small shallow dimples or depressions and/or intersecting grooves for assisting the retention of the implant.

With this invention, a soap cake which has dissolved away to an unmanageable washing size or one which has, through use, reduced considerably in thickness but is still of a manageable size, can be implanted into the recess of a WO 91/13970 PCT/AU91/00079 2 new host soap cake, and once implanted, can be used up entirely. Of course, it is advantageous for the implant to occur before the used cake wears to an extent where it becomes too small to be manageable and/or too fragile.

In order to more fully describe the invention, tqo embodiments are described hereunder in some further detail, with reference to the accompanying drawings in which: Fig. 1 shows a perspective view of a soap cake according to a first embodiment and a worn or used cake of reduced size, ready for integration with the host cake; Fig. 2 is a plan view of the cake of soap shown in Fig. 1; Fig. 3 is a sectional view along the lines Y-Y of Fig. 2; Fig. 4 is a longitudinal section along the lines X-X of Fig. 2; Figs 5 to 8 are longitudinal sections along the lines X-X of Fig. 2 showing the various stages of wear of both the host soap cake and the 'insert' soap cake; Fig. 8 showing that the insert soap cake has been completely consumed and the host soap cake worn to a size which is now suitable for implantation into a new host cake, whilst Fig. 9 is an elevational view showing a soap cake according to a second embodiment, which is suitable for nesting with an adjacent soap cake for packaging purposes.

Referring to Figs. 1 to 4 of the drawings, a soap cake is formed with an approximately oval-shaped recess 11 in one of its major faces, the recess 11 being dimensioned such that it will allow an implant 12 of a partially worn soap cake to be received therein while the implant 12 is still of a reasonable size. The periphery of the recess 11 (as shown in Fig. 2) is to resemble as closely as possible the profile of an average partially worn soap cake, the length and width of which will correspond approximately with the length and width of the recess 11. Preferably, the maximum depth of the recess 11 is approximately 50% of the thickness of the partially worn soap cake implant 12.

WO 91/13970 PCT/A U91/00079 3 The general shape of the base, 'side and end walls of the recess 11 are formed by a compound curve terminating at the periphery of the cavity. Preferably the recess 11 is formed as an oblong crater with its base wall 14 having a shallow dish shape which curves upwards progressively more steeply towards its periphery 15 on all sides as shown in Figs. 3 and 4 of the drawings. The general contour of the base wall of the cavity is shaped approximately to conform to the contour of the worn cake as shown in Fig. 8, it being appreciated that a cake of soap, after a period of use, will reduce in thickness at a much faster rate than that for its length and width.

In this embodiment, the surface of.the recess 11 is formed with an array of intersecting grooves 17 and small circular shaped dimples or depressions 18, the grooves 17 running longitudinally and transversely of the cake 10, with the dimples 18 being located within the land areas formed between the intersecting grooves 17. As shown in Fig. 2, the grooves 17 form a rectangular grid pattern with each of the grooves 17 being approximately 1mm in width and Imm in depth and being spaced approximately 10mm apart. The grooves 17 extend to the periphery 15 of the recess 11 with their depth gradually reducing over their last few millimetres to virtually zero at the periphery 15. The dimples 18 have a circular profile and a shallow dished cross section.

Referring to Fig. 5, there is shown a partially worn soap cake 12 inserted or implanted into the recess 11 of a host soap cake 10. This would normally be done with the worn smaller cake 12 in a wet condition, preferably just having been in use so that its surfaces are soft or in a slightly gelled or tacky condition. The recess 11 of the host cake may also be wet immediately prior to inserting the worn cake 12 but this is not essential. In use, one simply holds the new cake 10 in one hand with the recess 11 facing out, the worn cake 12 is placed into the recess 11 and pressed thereinto using the palm of the other hand. The 'pressing home' of the cake 12 is important to ensure proper retention WO 91/13970 PCT/AU91/00079 4 and bonding between the host and insert cakes. Preferably the insert cake 12 is pressed home with sufficient force so that it makes approximately continuous surface contact with the surface of the recess 11. The insert cake 12, being thinner and softer, will tend to conform to the shape of the recess 11. Any excess air and water trapped between the two cakes can be forced out mainly via the grooves 17. The slightly soft surface of the insert cake 12 is forced partially into the grooves 17 and smaller dimples 18 replacing air and/or water via the grooves 17. It is considered that the dimples 18 may act as 'suction cups' helping in part to keep the insert cake 12 retained within the recess 11 at least initially.

The merging of the softer surfaces of the insert cake 12 into the grooves 17 and dimples 18 of the host cake provides a physical keying together of the two surfaces, which also helps to retain the insert cake 12 in the recess 11.

Ideally, the insert cake 12 should be implanted when its profile is such that it will allow the thin shaped edges 21 of the insert cake 12 to fit snugly into the perimeter wall section of the recess 11 and in so doing help resist any shearing action between the two cakes which might otherwise cause the insert cake 12 to be dislodged from its host cake Referring to Fig. 6, the integrated 'host and insert' cake is shown after its initial stages of wear, with portions of both the host and insert cakes 10, 12 having been consumed, as would be expected, and the integrated cake having assumed an approximately smooth continuous curved surface 22. At this stage, the integrated cake, in typical usage conditions, would have been subjected to numerous alternating 'wetting' and 'drying' cycles, and as a result a considerable amount of bonding is able to take place at the interface between the cakes 10, 12. The pattern of grooves 17 allows some movement of moisture and/or air at the interface so encouraging a wetting/softening and a drying/ WO 91/13970 PCT/AU91/00079 solidifying cycle and in turn the fusing or moulding together of the two cakes 10, 12. This action is continuous throughout the life of the integrated cake until the stage of wear shown in Fig. 8 has been reached, that is, where all of the insert cake 12 has been consumed. The fusing action would normally take place over the whole of the interface but would tend to be more active at or near the perimeter of the insert cake 12. As the perimeter diminishes through wear during the life of the integrated cake so this fusing action is continually reinforcing the perimeter bond ensuring that the bond is continuous until the last minute portion of the insert soap cake 12 has been used.

Fig. 7 shows an integrated cake worn to a stage where only an extremely small fragment of the insert cake 12 remains, yet as a whole is in a manageable and usable form.

Fig. 8 §hoxs the original host cake 10 worn to a suitab'e size where it can now become an insert cake for a new t cake. It should be appreciated that the size of the cake shown in Fig. 8 is still sufficiently large to be easily manageable and although it can still be used as an insert if it is of a smaller size, it will become less and less manageable as its size decreases beyond this stage and so as product wastage has been eliminated, there is no reason to continue using the cake beyond this point the optimum insert size).

In the second embodiment shown in Fig. 9, the soap cake has on its other major face 26, i.e. that opposite to the face that contains the recess 11, a raised convex portion 27 which is shaped complementary to the recess 11, such that when two cakes 25 are placed together to form a stack as they may in a package or being stored prior to use, the cakes nest together with the raised portion 27 on one cake nesting into and filling the recess 11 on the adjacent cake 25. The nesting of any such stack of cakes 25 permits a significant reduction in the height of the stack. This of course makes for savings in packaging materials and in volume for the purposes of transport and warehousing.

W-O0 91/13970 PCT/AU91/00079 6 In a variation to the abovedescribed embodiment, the core material of the new host cake is formed of a contrasting colour to the material of the outer layers of the cake. In this way, a person can readily identify when the optimum insert size of the worn cake has been reached. Such a colour change facility would tend to act as a reminder to the user that it was time to implant the worn cake into a new one.

It will, of course, be appreciated that most soap cake formulations would be suitable for application with a product made in accordance with this invention in a simple one colour form. If a two colour system is utilised however, the formulation of each of the col.oured portions of the cake may, or may not, be of the same formulation. If of different formulations the two portions would obviously have to be chemically compatible.

In another variation, the surface of the recess 11 may be provided with protrusions (instead of or as well as the dimples) in order to provide greater surface area contact between the mating surfaces of the host and insert cakes and to further assist their integration.

A brief consideration of the abovedescribed embodiment will indicate that the -invention provides a very simple and inexpensive means for eliminating soap wastage by providing a soap cake which is able to have integrated therewith a partly consumed soap cake to in turn allow the latter to be consumed entirely.

Claims (9)

1. A cake of soap (hereinafter "the host cake") having recess forming walls in one of its major surfaces to define a recess shaped and dimensioned for receiving therein an implant of a smaller worn or used soap cake, characterised by said recess forming walls being provided with keying means for physically keying together the mating surfaces of the host cake and implant when the latter is manually pressed into the recess, whereby the implant, when thus received in the recess is fast with and becomes integrated with the host cake, said keying means comprising an array of elongate grooves at least partly into which respective surface portions of said implant cake are forced, when the host cake and the implant cake are pressed together, said grooves connecting to the periphery of said recess so as to permit water and/or air to move therealong to thereby promote wetting/softening and drying/solidifying cycles and in turn the fusing together of said mating surfaces of the host cake and the implant.

2. A cake of soap according to claim 1 wherein said keying means further comprises an array of shallow dimples or depressions formed over a major part of the surface area of said recess.

3. A cake of soap according to claim 1 or 2 wherein said grooves intersect and extend longitudinally and transversely of the host cake.

4. A cake of soap according to claim 3 when appended to claim 2 wherein said dimples are respectively located in land areas formed between said intersecting grooves. A cake of soap according to claim 2 wherein said dimples or depressions have a circular profile and a shallow dished cross section.

PCT/ AU 9 1 0 0 0 7 9 RECEIVEO 2 0 MAR 1992 8

6. A cake of soap according to any one of claims 1 to wherein each said groove is approximately 1mm in width and 1mm in depth, the spacing between adjacent grooves being approximately

7. A cake of soap according to any one of the preceding claims which comprises an internal core portion formed of a contrasting colour to that of the remainder of the cake.

8. A cake of soap according to any one of the preceding claims comprising a convexly curved protrusion on its other major surface, which is shaped complementary to said recess.

9. A cake of soap according to any one of the preceding claims wherein the recess comprises a concavely curved wall, the curvature of which matches the curvature of the underside of the implant cake, said recess being formed centrally of the host cake.