SERIAL APPLICATOR DEVICE FIELD OF THE INVENTION The present invention relates to the field of applicators and dispensers. More specifically, the present invention relates to a device for the dosing and application of controlled dose of a substance to a surface. BACKGROUND OF THE INVENTION Liquid or paste applicators serve to apply a controlled quantity of a substance to a target surface. Devices of this kind divide into two primary categories: (a) those which merely take a liquid or paste stored in an external container and apply it to the target surface, and (b) those that combine both the storage function and the application function. Various types of brushes and spatulas fall into the former category, whereas tubes or pouch dispensers with integral spatulas fall into the latter. The present invention falls within this latter category of integraj dispenser/applicators while, in addition, overcoming the limitations of such products for specific applications. Various existing products and approaches among the existing products in this dispenser/applicator category suffer from one or more of the following limitations: (a) inexact dosing, (b) wastage of substance dispensed, (c) difficulty in applying to a precise point, (d) difficulty in enabling simultaneous or sequential application of a number of different substances, and (d) restriction to only one type of applicator (sponge, foam, brush, spatula, etc.). For example, the use of tube applicators with an integral spatula for the application of adhesives are often wasteful not just in regard to adhesive emitted from the tube but not applied, but also in terms of the degradation of the material and/or the blocking of the tube outlet due to the contact of air with the adhesive. Other prior art approaches use a capsular storage of precise doses of material, but are then difficult to apply to a point target surface or face problems in sequential or simultaneous application of two or more different substances. The prior art in this field contains a number of examples of attempts to overcome one or more of the above limitations, US 5,823,391 describes a dual chamber flexible tube dispensing package. While this dispenser does enable simultaneous dosing of two different substances, it cannot do so sequentially, nor
can it dose exact volumes. US 4,826,048 also describes a mechanism for the simultaneous dispensing of a plurality of substances, using two separate reservoirs, a discharge pump for each reservoir, and a common handle activating both pumps simultaneously. Similarly, US 6,462,025 envisages a similar dual dispensing pump for the simultaneous dispensing of an antibiotic together with benzoyl peroxide for treatment of acne. However, while both of the above mechanisms are capable of applying the substance(s) to a narrow target surface, neither of them is capable of delivering a plurality of substances in a sequential manner.
A further series of prior art devices utilizes a principle whereby capsules containing the substance(s) to be dispensed are fabricated on a sheet, and pressed against a target surface. US 5,242,433; US 5,417,674; US 5,470,323 and US 5,562,642 describe a system for topical drug delivery where two in-tandem absorbent pads, each containing a separate substances are packaged side by side on a base sheet. The related US 5,460,620 describes a method of applying said in-tandem pads by removing a cover sheet. In further developments of this concept of a dispensing sheet, US 6,325,565 and US 6,315,482 describe sheets with embedded capsules or micro-reservoirs containing anti-perspirant or deodorant substances to be dispensed when the sheet is pressed against the skin surface, the capsules thereby being ruptured due to the pressure applied. In this arrangement, where a plurality of adjacent capsules contain different substances, the different substances are applied simultaneously. However, applying said substances sequentially requires tailoring of the geometry of the sheet so as to enable the rupturing of one type of capsule to precede the rupturing of another. US 6,508,602 describes a further modification of this concept, whereby different capsules or pouches rupture at differing pressures, thereby enabling a sequential operation to be performed by increasing the pressure applied over time. A further dispenser sheet mechanism is provided by US 6,001 ,380; wherein an applicator sheet comprising a plurality of discrete areas containing at least two dermatological agents, said agent being released on contact with wet skin by the action of the water. Thus, while these prior art sheet applicator mechanisms can easily accommodate simultaneous application of disparate substances, the sequential application of disparate substances is either impossible or relatively complex. Furthermore, none of these sheet
applicators are capable of applying the required substances to a point target surface. It is therefore the object of this invention to provide an integrated dispenser/applicator capable of dispensing controlled doses of a substance to a point target surface. It is also the object of the present invention to dispense either a single substance or a plurality of substances. It is a further object of the present invention to enable a plurality of substances to be applied sequentially. It is a still further object of the present invention to enable a plurality of applicator heads to be utilized to apply the substance(s) to said target surface. It is furthermore the object of the present invention to enable accurate dosing of the substance(s) dispensed while preventing air contamination of the substance(s) and also preventing contamination of the applicator head(s) used. These and other objects of this invention will become more evident in the summary of the invention and in the description of the preferred embodiment. SUMMARY OF THE INVENTION According to the present invention there is now provided a device for the dosing and application of controlled dose of a substance to a surface. More specifically according to the present invention there is now provided a device for the dosing and application of a controlled dose of a substance to a target area, said device comprising an elongate strip containing a plurality of capsules, a housing, and a transport mechanism within said housing, whereby said mechanism advances said strip toward the applicator end of said device at which point said strip is peelably separable to expose the content of said capsule at said applicator end and enabling said content to be applied to a target surface. Said device enables the application of substances from capsules to a small target area, said device comprising: an elongate strip containing said capsules, a housing, and a means within said housing whereby said elongate strip is parted at the applicator end of said device to release and apply the substance. The strip utilized in the present invention is based upon a modification of a concept previously used for inhalation devices as described in US 5,590,645; US 5,860,419;
US 5,873,360; US 6,032,666; US 6,065,472; US 6,098,619; US 6,378,519; and US 6,536,427; all hereby incorporated by reference. In a preferred embodiment, said strip is formed from a base sheet having a plurality of recesses spaced along its length and a lid sheet hermetically but peelably sealed thereto to define a plurality of containers, hereinafter termed capsules. In an alternative embodiment, said strip is formed using form-fill-seal technology. . Whereas in the inhaler implementation discussed above each such capsule contains an inhalable medicament in powder form, in the present invention the contents of the capsules are either (a) substances which are applied to a target surface (typically skin) by physical contact such as smearing or brushing, or (b) applicator tips for accomplishing said physical contact. Additionally, said capsule may of course contain both the applicator tip and the substance to be applied. As the strip is moved forward via a transport mechanism through the housing toward the applicator end of the device, the layers of said strip are peelably separated, thereby bringing the capsule's content into contact with the target surface. Where said capsule content is a substance, it is applied to the target surface either by the sheet(s) of which the strap is formed or by a pre-located applicator tip within the device. Where said capsule content is an applicator tip, said tip serves to apply a substance released from a further capsule. Where said capsule contains both a substance and an applicator tip, said tip serve to apply said substance, possibly together with previously applied substances. As will be seen from the detailed description below, the generality of the device of the present invention is such either one substance may be applied, one dose at a time, or that a plurality of different substances may be applied sequentially. In this manner, the device may be used to apply a complete medical or cosmetic treatment or procedure comprising a number of stages. For example, in treating a cut, first a cleansing and anaesthetizing substance can applied, followed by an active ingredient to treat the cut, followed by a protective covering such as a liquid Band-Aid. In preferred embodiments of the present invention said device further comprises a sequencing mechanism ensuring that the stages of the treatment are performed as a group, a further action being required by the user before the next such treatment is performed. For example, the depression of one button may serve to move from stage to stage, whereas a further button needs to
be depressed before the next sequence can commence. Alternatively, a further depression of the same button can commence the next sequence. In preferred embodiments of the present invention said device further comprises a mixing mechanism enabling the contents of two or more capsule to be mixed directly prior to application. Advantageously, this enables the application of substances, which need to be stored separately but applied together. Examples include everything from simple two-component adhesives to medical products such as the antibiotic - benzoyl peroxide acne treatment referenced above. As will be realized, the device of the present invention enables an application system and method offering greater convenience, improved safety and different form factors than those provided by existing systems. Advantageously, this device and its method of operation overcome the difficulties inherent in trying to apply a series of doses to a target surface, especially in a given sequential order. However, even where the use of the device is relatively simple, such as for the application of a single-substance adhesive, it still possesses advantages over existing systems in that it prevents waste and fouling of the applicator tip. The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood. With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 shows a roll-to-roll embodiment of the device;
Figure 2 illustrates an isometric detail of an elongate strip suitable for use within the device as it reaches the applicator end of said device; Figure 3 shows the use of applicator tips within capsules as they reach the application end of the device; and Figure 4 illustrates a closed-loop embodiment of the device. DETAILED DESCRIPTION OF THE DRAWINGS The present invention will be described in detail according to the preferred embodiments illustrated in the accompanying drawings. Like reference numerals are used to identify identical components in the various views. Referring now to Figure 1a, a roll-to-roll configuration of the device is shown, said device comprising a housing 10, an applicator end 11 , a feeder roll 12, two take-up chambers 13. A transport mechanism 14 serves to unwind the strip 15 from its feeder roll 12 and move it toward the applicator end 11 of the device. In a preferred embodiment, the "strip 15 further comprises holes for the transport mechanism 14 to engage, and a plurality of capsules 17 formed within said strip. The device further comprises a button 19 connected by a ratchet (not shown) to said transport mechanism 14 such that each depression of said button 19 serves to move the strip 15 forward by one capsule position. In a preferred embodiment of said transport mechanism 14, a rubber tenser wheel is employed which has a flexible section between the hub and the circumference, whereby the sprockets of said wheel engage the holes 16 in the strip 15 such that the friction of the hub on its axle keeps the flexible section distorted and the strip 15 under tension. This transport mechanism 14 serves to advance the strip 15 towards the applicator end 11 of the device, where the upper and lower surfaces of the strip 15 are peelably separated on passing between the two pulleys 18. On said separation, the substance or applicator tip enclosed within each capsule 17 is applied, typically to the user's skin, the separated layers of the strip then being separately fed into the two take-up chambers 13. In this embodiment, taking advantage of the strip's rigidity, the strip 15 will roll/unroll and accommodate itself in the specified chambers and thus no spools are required. The two pulleys 18 are mounted on a flexible fork that enables them to move farther away from one another as they rotate but keeps them close together in application position. An optional substance-mixing
mechanism may be located adjacent to the strip 15 prior to the point where the strip 15 is separated. In a preferred embodiment said mixihg mechanism may use a roller moving within a guide groove 20. (The broken line around said guide groove
20 shows the area, which is described in more detail in Figure 1 b below.) In a further embodiment of the transport mechanism, the strip 15 is pulled forward by friction as opposed to the tractor mechanism described above. In a still further embodiment the transport mechanism comes after the application surface; i.e. it pulls the separated stretches of the strip, potentially by winding them on a spool turned by said mechanism. In either case, the transport mechanism can engage with the strip either in a linear or a rotating manner. Referring now to Figure 1b, the detailed area delimited by the broken line in Figure 1a above is shown, and illustrates a preferred embodiment of a mixing mechanism. The objective of said mixing mechanism is to mix the substances contained in one or more adjacent capsules 22 directly prior to their application. Advantageously, this mechanism provides for those cases in which a plurality of mutually incompatible substances need to be stored separately but applied simultaneously. In the preferred embodiment shown, a mixing roller 21 is moved along a guide groove 20, thereby squeezing the adjacent capsules 22 against part of the housing. As these adjacent capsules 22 are squeezed, the pressure within the capsule ruptures the seal between each two adjacent capsules such that they combine into a larger combined or merged capsule. Further movement of the roller
21 can then mix the contents of said combined capsule by continued up and down motion. In this way, a combined capsule containing the various substances in a mixed fashion is prepared for use at the application end 11 of the device. As said combined capsule proceeds towards the application end 11 , the various substances are mixed further as the strip is manipulated through the device. Referring now to Figure 2, an isometric view of a preferred embodiment of the strip 15 is provided, showing the lower surface 24 and upper surface 25 and a capsule 17 formed therebetween. As this strip is peelably separated, the inner surfaces 26 of the strip are exposed and can serve as applicators against the skin of the product contained within said capsule 17. Said capsules comprise a trapped volume of a substance sealed between the layers of the strip, and may be
fabricated using a form-fill-seal machine or by using a heated needle to inject a liquid into the capsules 17 after their formation. In a further embodiment, one or more sides of the strip are thermoformed to form indentations, the substance is then deposited in the indentations so formed (either directly or through a hole in a further, vented, layer), and then the upper layer of the strip is adhered to it. In a further preferred embodiment of the strip, a sequencing mechanism is implemented by providing sequencing marks or perforations (not shown) along the strip 15, said marks serving to identify the start and/or end point of a sequence of capsules that are to be applied. In this embodiment, a sequence of substances may be applied to the skin, with each capsule containing a different substance or applicator tip. As the sequence is concluded, the strip 15 will not advance any more until a further action such as the depression of a button is performed. For example, a protrusion may catch on these perforations, said protrusion being connected to a release button which needs to be depressed before the next sequence can start. In this way, a means of ensuring the integrity of a complete sequential application is maintained. Additional perforations to enable tractor motion 16 may exist on the strip 15 independently of said sequencing marks. Referring now to Figure 3, the strip 15 of the present invention is shown as it is transported toward the applicator end 11 of the device. Figure 3a shows a sponge-type applicator surface 30 as it is stored within a capsule, typically together with a substance to be applied by said sponge. As it reaches the applicator end 11 of the device, the peelable separation of the strip 15 exposes the sponge surface 32, enabling it to apply the contents of the capsule. In this embodiment, the applicator tip (i.e. the sponge) is packaged together with the substance to be applied. Figure 3b shows a different approach, where the applicator tip and the substance to be applied are stored separately. In an example of this preferred embodiment, each brush applicator tip 34 is stored within a dry capsule while the adjacent capsule 36 contains the substance to be applied. By ensuring the correct sequence, the substance is deposited on the skin first, and then the next capsule brings the brush applicator tip 39 to the application end 11 for applying or rubbing in said substance. Alternatively, by employing a mixing mechanism such as that described in Figure 1b above, the contents of these
capsules can be mixed directly before application, and thus the applicator tip will already have the substance on it before said tip 36 appears at the applicator end 11. As will be obvious to one skilled in the art, numerous applicator tips can be used in this arrangement, including but not limited to various nozzles, spray nozzles, and spatulas, in addition to the sponges and brushes described above. In a trivial case of this mechanism, the inner surface of the strip itself serves as the applying surface or applicator tip. Referring now to Figure 4, a preferred closed-loop embodiment of the device of the present invention is shown. Advantageously, this embodiment employs a closed loop of the strip 15 such that a more compact and less expensive implementation of the device may be fabricated. Said embodiment will typically be used to deliver and apply one sequence of substances to the target area and is similar in use to a syringe. In this preferred embodiment the strap comprises two closed-loop straps, which are connected together in a section that contains the capsules. Said straps 15 are looped around a frame 50 where they are held taught by cantilever spring arms. 45 that extend from said frame 50. On depressing the button 46, said frame 50 is pushed down through the housing 51 , thus exposing the application end 11 through a hole at the base of said housing 51. As the frame 50 is pushed downwards, a detent tooth 40 extending from the housing 51 holds the holds the outer loop of the strap 15, preventing said strap 15 from moving with the frame 50, and thus causing a relative motion between the strap 15 and the frame 50. This relative motion causes the central section of the strap 15 (containing the capsules) to advance by one capsule position. As the frame 50 moves downward, a further protrusion 42 on the housing 51 presses against the cam 43 on the frame 50, thereby opening the application end 11 sufficiently for the capsule to pass through. Said opening of the application end 11 is enabled by the separation of the prongs of the flexible fork 44 in the frame 50. A sequencing mechanism holds the frame 50 in the exposed position shown in figure 4b until a second depression of the button 46 releases the frame such that the spring 47 causes the frame 50 to return to its initial position as shown in figure 4a. In a preferred embodiment, said sequencing mechanism comprises a labyrinth 48 in the housing 51 and a cantilever
spring arm 49 with a protrusion that travels within said labyrinth 48 where it engages and disengages according to a sequence dictated by said labyrinth 48. As will be obvious to one skilled in art, various types of sequencing mechanism may be implemented in the device of the present invention, and may, for example, be based either on the mechanism employed in the roll-to-roll embodiment shown in Figure 1 or on that employed in the closed-loop embodiment shown in Figure 4. Said mechanism can be designed to perform various sequences including but not limited to sequences that involves more then one button and sequences that involves accumulated actions. The sequencing mechanism can further comprise (a) a counting means to show the current place within the sequence, for instance using indicia on a dial or on the strap; and (b) a locking means to prevent an action at any point in a sequence, said means being either mechanical or electronic. An "accumulated action" as described herein refers to the case where the force applied to move the strip through the device also serves to prime a further or secondary mechanism located adjacent to the application,, end of the device. In a preferred embodiment, said secondary mechanism is a spring which is compressed as the device is used, said spring later being released at the appropriate point in the application sequence. Such a mechanism can, for example, serve to apply pressure to a capsule, causing it to spray its contents through a nozzle or other applicator tip. The strip used in the present invention can be fabricated using a number of well known materials and methods. For example, some of the prior art patents incorporated above suggest that the layers comprising the strip be formed of a plastics/aluminum laminate, where they be adhered to each by heat sealing. By way of example, the upper layer may be a laminate consisting of 50 gsm bleach kraftpaper/12 micron polyester (PETP) film/20 micron soft temper aluminum foil/9 gsm vinylic peelable heat seal lacquer (sealable to PVC), and the lower layer material may be a laminate consisting of 100 micron PVC/45 micron soft temper aluminum foil/25 micron orientated polyamide. In this case, the lacquer of the upper layer material is sealed to the PVC layer of the lower layer material to provide the peelable seal between the upper and lower sheets. Alternatively a thin polyethylene layer on the inner surfaces of both layers can also serve as the heat-
seal layer. In general any combination of paper, plastics and metal (e.g. aluminum) can serve to fabricate the strip. Furthermore, several layers may be used in the strip's fabrication, providing that, on peelable separation, said strip parts into only two layers as shown in the above embodiments. As will be obvious to one skilled in the art, the applicator of the present invention supports numerous modes of action: Substances can be applied either singly or after mixing; a series of different substances can be applied sequentially; combinations of substances can be applied sequentially; the inner surface of the strip can serve as the applicator surface "as is"; or a range of applicator tips can be provided from within the capsules of the strip. Similarly a plurality of straps can be manipulated in parallel, either by having more than one strip mounted in parallel on the same mechanism or by having more than one mechanism working in parallel. In addition to the cosmetic and medical uses described above, the device can also be used as a sticker or tattoo applicator where its first action is to spread glue or other liquid, followed by the application of a sticker or tattoo. In a, further preferred embodiment of the device, the application of the substance(s) to the skin can be enhanced by any combination of heat, vibrations or electrophoresis as required. Lastly, the device of the present invention can either be operated manually, or can be operated by an external activation machine to which it is attached. In this manner, the device of the present invention can be treated as a replaceable cartridge for a more complex device for which the sequential application of substances is just one part of a more extensive procedure or process. While the invention has been shown herein in what is presently conceived to be the most practical and preferred embodiment thereof, it will be apparent to those of ordinary skill in the art that many modifications may be made thereof within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and devices.