LIQUID APPLICATOR

Abstract: An applicator for liquid shoe polish or other liquid comprises a porous insert (4) mounted within a cup (14) such that an exposed tip portion (30) projects from the open mouth of the cup (14), the tip portion (30) defining an applicator zone for the liquid. Normal liquid flow to the applicator zone occurs through the porous insert. A groove (28) in the wall of the cup (14) is openable in response to deflection of the tip portion (30) in a predetermined direction to permit by-pass flow of the liquid to the applicator zone.

Description: "LIQUID APPLICATOR" The present invention relates to liquid applicators, and more particularly, but not exclusively, to applicators for liquid shoe polish. Previously proposed applicators for liquid shoe polish have not been entirely satisfactory in that inadequate control is provided over the flow rate of the polish being applied to the shoe, with the result that there is a tendency either for insufficient polish to be applied or, excessive amounts of polish to be applied. More particularly, one previously proposed applicator comprises, a rubber applicator cap which fits over the mout of a container for liquid shoe polish. The cap includes an integral closure diaphragm provided with a slit which, in an undefoππed mode of the cap, is held closed by the resilience of the rubber. Beyond the diaphragm, the cap supports an open cell foam pad. In use, when pressure is applied between the applicator and the shoe with the container held inverted, the applicator will deform to open the slit in the diaphragm and thus permit flow of polish from the container via the open slit in the diaphragm into the central region of the pad in order to be spread by the pad. With this previously proposed construction, the slit is, basically, either open or shut and it is impossible to control the flow rate through the slit. The pad itself does not tend to retain the polish, and apart from the difficulties which arise from the absence of the ability to properly control the flow rate, it is difficult to achieve uniform application of the polish. Another previously proposed applicator comprises a cylindrical sponge pad which extends from the mouth of the polish container, with the outer axial end face of the sponge constituting the face by which the polish is applied. The sponge extends into the interior of the container via an annular cup-like seating member which compresses the cylindrical sponge approximately midway along its length and forms a seal between the sponge and the container mouth. Air bleed holes lead from the base of the cup into the interior of the container, these holes normally being blocked* by the body of the sponge within the cup. When the container-is inverted, liquid polish flows to the outer end of the sponge by capillary action. Deformation of the sponge, which may occur as the sponge is wiped over the shoe, tends to cause part of the sponge body to move away from the body of the cup and thus expose the air bleed holes to permit flow of air into the interior of the container in order to maintain the capillary flow through the sponge. A limited degree of control can be obtained by manipulating the applicator so that greater or lesser amounts of air bleed into the container during use, but as the flow is only a capillary flow the extent of possible control is not very great. This means that for some uses , such as childrens' shoes, the minimum normal flow rate may be too great, whereas for use on, for example mens' boots, the maximum normal flow rate may be insufficient. According to the present invention, there is provided a liquid applicator comprising an enclosure adapted to communicate with the interior of a liquid container, a porous member located within the enclosure and having an exposed tip portion projecting from an open mouth of the enclosure, said porous member permitting liquid flow therethrough from a base part of the porous member to the tip portion which defines an applicator zone of the applicator, and passage means for permitting by-pass flow of the liquid to the applicator zone of the applicator, said passage means comprising a groove formed in the peripheral wall of the enclosure and extending to a position adjacent the mouth of the enclosure, said porous member normally providing a seal against by-pass liquid flow through the groove, the tip portion of the porous member being deflectable in a predetermined direction whereby to break the seal. Preferably, the porous member is such as to permit capillary flow of the liquid. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a longitudinal section through a cap of an applicator in accordance with a first embodiment of the invention; Figure 2 is a plan view of the cap shown in Figure 1; Figure 3 is a transverse section through the cap, and additionally showing a porous insert within the cap; Figure 4 is a view of the cap in the direction of arrow A in Figure 2. Figure 5 is a longitudinal section through a cap of an applicator in accordance with a second embodiment -of the invention; Figure 6 is a plan view of the cap shown in Figure 5; Figure 7 is a transverse section through the cap shown in Figure 5; and Figure 8 is a transverse section showing a lid for the cap of Figures 5 to 7; The applicator- shown in Figures 1 to 4 comprises a moulded cap 2 and a porous insert 4 seated within the cap, the insert preferably consisting of a porous foam. The body of the cap comprises a skirt portion 6 designed to fit over a shoulder of a container 8 of which the upper part is shown in broken lines in Figure 1, the lower part of the skirt portion 6 having inwardly-projecting lugs 10 which are a snap-fit within a peripheral groove 12 in the container shoulder to ensure positive retention of the cap 2 on the container 8. The lower part of the skirt portion 6 is an interference fit on the container shoulder. The interior of the cap body is formed with an upwardly-open enclosure in the form of a cup 14 of elongate rectangular cross-section to receive the porous insert 4 which is of similar cross-section. An . opening at the bottom of the cup communicates with the interior of the container via a downwardly-projecting tubular spigot 16 of circular section which fits within the neck 18 of the container 8. The exterior surface of the spigot 16 is provided with a locally-enlarged zone 16a which is an interference fit with the interior surface of the container neck 18 to provide a seal to prevent leakage of air into the interior of the container 8 between the external surface of the spigot 16 and the internal surface of the container neck 18. As will be seen from Figure 3, one of the two longer sides of the cup 14 terminates at a height below that of the other of the longer sides whereby the open top of the cup 14 lies in a plane inclined at an acute angle to the plane of Figure 1, typically an angle of about 30-50° to the vertical. For simplicity, the shorter of the two sides (designated 20) will now be referred to as the front side, and the longer side (designated 22) will be referred to as the rear side. The front and rear sides 20,22 of the cup 14 are each formed with inwardly-projecting barb-like retaining tangs 24 which bite into the insert 4 within the cup 14 in order to prevent withdrawal of the insert 4 during use. The rear side 22 of the cup 14 is formed with a relatively wide liquid feed groove 26 which extends upwardly from the tubular spigot 16. At its upper end portion, the feed groove 26 merges into a smaller section control groove 28 which continues upwardly to terminate at a distance beneath the upper edge of the rear side 22. The porous insert 4 acts as a capillary foam for the particular liquid being dispensed. The insert is initially of rectangular cross-section and is subjected to an areal compression when fitted into the cup 14. Typically, the transverse cross-sectional area of the cup 14 is about 25% less than that of the uncompressed insert 4. The purpose of this compression is to ensure that a seal exists between the surface of the insert 4 and the peripheral wall of the cup 14 for the reasons to be described later. The longitudinal corner zones of the cup 14 are rounded as shown in Figure 2 to provide an effective seal with the longitudinal edge portions of the insert 4. When the insert 4 is seated within the cup 14 a substantially air-tight seal is defined between the insert 4 and the peripheral wall of the cup 14 at least in the upper part thereof, and it is to be noted that the control groove 28 terminates- a sufficient distance beneath the upper edge of the rear side 22 of the cup 14 to define a sealing land which ensures that an adequate seal is provided between the insert and the rear side 22 above the upper end of the control groove 28. The insert 4 projects outwardly beyond the cup 14 to define an applicator tip 30, and the inclined configuration of the open top of the cup 14 provides, for the applicator tip 30, a large area front face 30a, and a smaller area rear face 30b. The inclination also provides for deflection of the tip preferentially in a predetermined direction as will be described shortly. In use, when the container 8 is inverted, liquid will flow to the applicator tip 30 by capillary.action. If the applicator tip 30 is applied to the shoe with the front face 30a of the tip 30 wiping the surface of the shoe, polish is applied to the shoe by the capillary flow through the tip 30. However, the seal between the insert 4 and the cup 14 will be unaffected by this action, and as air is unable to enter the container either between the cooperating surfaces of the insert 4 and the cap 2, or between the cap 2 and the container 8, a vacuum will begin to establish within the container and this will tend to reduce the capillary flow rate. If this occurs and results in an insufficient flow for * - the particular use, by periodically turning the container and briefly touching the rear face 30b of the tip 30 against the shoe, the tip 30 will be deformed forwardly away from the rear side 22 of the cup 14 (as shown in broken lines in Figure 3) thereby exposing the upper end of the control groove 28 whereby the pressure within the container can be at least partially restored by inflow of air via the control groove 28 and the wider feed groove 26; this, in turn, restores the capillary flow for application of the liquid by the front face 30a of the tip 30. The frequency at which this action is performed will, in effect, act as a means for controlling the capillary flow. The application of the rear face 30b of the tip 30 to the shoe to open the control groove 28 has another important function as will now be described. As mentioned above, if the rear face 30b of the tip 30 is briefly touched against the shoe in order to momentarily deflect the tip 30 forwardly, the control groove 28 will be opened to permit ingress of air; this will occur irrespective of the inclination of the container . 8 at the time. If, however, the tip 30 is maintained in its forwardly-deflected position other than for very brief periods, when the container is inverted liquid will flow to the rear face 30b of the tip 30, directly via the feed groove 26 and the control groove 28, as a by-pass flow separate from the capillary flow through the insert 4 itself. In this mode, a high flow rate to the tip 30 can be obtained as may be required when cleaning a large boot, for example. Within limits, the greater the pressure applied by the user to deflect the tip 30, the greater will be the area of the exposed part of the control groove 28 and the greater will be the by-pass flow. Air will also pass back into the container via the grooves 28 and 26 during this action in order to maintain the capillary flow and the by-pass flow. In a practical embodiment, the insert consists of a PVA (polyvinyl alcohol) sponge in the form of a three-dimensional interconnected porous structure. The pore size of the structure will be dependent on the viscosity of the particular liquid formulation, although in practice the average pore size will be between 30μ and 350u , more usually between about 50 and 150μ . With pore sizes below 30 the pores are likely to be blocked by pigments within the liquid, the risk of blockages being substantially reduced at pore sizes of 50 and above. At pore sizes of above 150μ problems might arise in securing an adequate seal between the insert and the cap, although the larger pore sizes might be necessary for use with highly pigmented polishes, such as whiting. For general purpose polishes an average pore size of 60μ , with a porosity of 85-95% has been found to give good results. Although PVA foam is exemplified for use in a practical embodiment of the invention, other foams may be used, for example high density polyethylene, polyurethane, polyester or neoprene foam. It is not essential for the porous insert to consist of a foam; for example the insert may consist of a bundle of fibres or a felt, or even bonded paper. In practice the insert should be of a relatively rigid material rather than a relatively soft material; More particularly, the insert should be such that under in use conditions, the applicator tip 30 will not, under compressive loading, compress to an extent sufficient to permit the outer end of the cup to scrape along the surface of the- shoe, and that when the tip 30 is deflected (as by applying the rear face 30b of the tip against the shoe) , the insert will deform arcuately in a zone including the end portion of the control groove 28. The distance between the upper end of the control groove 28 and the upper edge of the rear face 22 of the cup 14 is of importance in practice. If this distance is too small, an inadequate seal may be formed, thereby permitting uncontrolled air leakage into the container and uncontrolled flow of liquid when the container is inverted. If, however, the distance is too large, excessive deflection of the tip 30 is required to open the control groove 28. It has been determined that if the control groove 28 terminates about 3mm beneath the upper edge of the rear face 22, effective sealing is obtained without requiring excessive deflection of the tip 30 to open the control groove 28. With this preferred configuration, the container could be held inverted for at least half a minute without dripping. Inadequate sealing was obtained with a distance of less than 2mm between the end of the groove 28 and the upper edge. In general it has been determined that the distance should be between about 2mm and 4mm, with about 3mm being preferred. In the practical embodiment, the applicator tip 30 is about 28mm wide and projects from the end of the cup by about 4 to 5mm. The control groove 28 must be of a sufficient depth to ensure that the insert 4 does not deform into the groove and block the groove. For this reason, it has been determined that the groove should be at least 0.2mm in depth, preferably at least 0.5mm. The cross-sectional area of the control groove 28 is determined by the required maximum by-pass flow rate of the liquid. It is to be noted that the larger section feed groove 26 merges smoothly with the control groove 28 in order to prevent air locks. The feed groove 26 acts as a reservoir for the control groove 28 whereby to provide for quicker flow response to opening of the control groove 28 when the tip 30 is deflected for by-pass liquid flow. The container is provided with a removable lid (not shown) which fits over the cap 2 with a sealing fit. In modified form of this embodiment, the spigot 16 and neck 18 may be of oval or elliptical section, rather than of circular section as shown. Also, the lugs 10 may be replaced by a continuous ring which snaps into engagement with a groove on the container shoulder. A modified form of cap is shown in Figures 5 to 7. Whereas the cap 2 of Figures 1 to 4 is of approximately rectangular section with its longer sides rounded, the cap 40 in Figures 5 to 7 is of circular section in its lower part, and of rectangular section in its upper part. However in terms of its basic construction and function the cap 40 is substantially identical to the cap 2 and it will be seen that the cap 40 includes upwardly-open cup 14 of rectangular section to receive the porous insert 4, the cup 14 including insert-retaining tangs 24, and feed and control grooves 26, 28 with the open top of the cup 14 being inclined, whereby to permit the functions and operations described in connection with Figures 1 to 4. The base of the cup 14 is defined by transverse webs 42. At its lower end portion, the cap 40 comprises a tubular spigot 44 which is arranged to lie within the container neck 46, which is shown in broken lines in Figure 5. An annular shoulder formation 48 which surrounds the spigot 44 carries an inwardly-directed tang 50 (see Figure 7) which snaps into engagement with a groove in the external surface of the container neck 46 whereby to retain the cap 40 on the neck 46. Above the groove, the neck 46 is formed with an annular sealing rib 52 which engages the inner surface of the shoulder formation 48 in order to provide a liquid-tight seal between the container and the cap 40. A removable lid 60 which defines a sealed enclosure for the insert 4 is shown in Figure 8. The lid.60 is of three-part construction comprising a body 62 which engages as a snap-fit on the container, a top 64 which is snap-fitted or welded into the upper end portion of the body 62, and an annular sealing member 66 of urethane, rubber or other suitable compressible material interposed between the lid body 62 and top 64. More particularly, the lid body 62 is formed with an inwardly-directed annular flange 68 which supports the sealing member 66. The bottom edge of the lid top 64 faces the annular flange 68 and forms an annular knife edge 70 which engages into the surfac of an annular groove 72 extending around the sealing member 66 with the sealing member 66 thus being compressed between the knife edge 70 of the lid top 64 and the flange 68 on the lid body 62. The knife edge 70 provides an effective seal between the lid top 64 and the sealing member 66 without requiring close tolerances when manufacturing the components, and without requiring high sealing forces which might act to cause deformation of the lid top 64 or body 62. The upper, inner, edge portion of the sealing member 66 , sealingly engages the cap 40 beneath the upper end of the cup 14. There is thus defined between the cap 40, the sealing member 66 and the lid top 64 a sealed enclosure 72 within which the applicator tip 30 lies when the lid 60 is in position. This enclosure forms a liquid-tight reservoir of small volume so that when the reservoir is filled with a small volume of liquid, as may occur by capillary flow through the insert 4 if the container is inverted for a period of time or if the container is subject to reduced pressures as may occur in an aircraft, only a few further drops of liquid into the reservoir will increase the pressure sufficiently to prevent further capillary flow. The small volume liquid reservoir also reduces drying out of the applicator tip 30, and improves shelf life. A similar sealing lid of appropriate shape may also be used in conjunction with the applicator of Figures 1 to 4. To summarize, in contradistinction to the previously proposed applicators described above, the applicator in accordance with the preferred embodiments of the invention permits a controllable capillary flow, supplemented when required by a controllable by-pass flow.- The control is achieved simply by the user reversing the orientation of the applicator so that the rear face 30b of the tip 30 contacts the shoe and is deflected. Control is therefore effected by a positive action on the part of the user, and the user will quickly acquire the actions necessary for this. In the embodiments described, the porous insert is arranged to provide for capillary flow of the liquid being dispensed, and this is applicable irrespective of whether the insert is composed of a sponge or is of other porous structure for example a bundle of fibres. It is envisaged, however, that the porous insert could be such as to provide a restricted flow other than a capillary flow. For example, the insert might be composed of a microporous foam. Even when the flow through the insert is other than a capillary flow, a degree of control over this flow will be possible due to the build-up of vacuum within the container with the ability to at least partially restore the internal pressure in a controlled manner, as described previously. However, greater control can be achieved when the flow is a capillary flow and it is for this reason that it is preferred to provide for capillary flow through the insert. The embodiments have been described by way of example only and modifications are possible within the scope of the invention.

Claims: CLAIMS : 1. A liquid applicator comprising an enclosure adapted to communicate with the interior of a liquid container, a porous member located within the enclosure and having an exposed tip portion projecting from an open mouth of the enclosure, said porous member permitting liquid flow therethrough from a base part of the porous member to the tip portion which defines an applicator zone of the applicator, and passage means for permitting by-pass flow of the liquid to the applicator zone of the applicator, said passage means comprising a groove formed in the peripheral wall of the enclosure and extending to a position adjacent the mouth of the enclosure, said porous member normally providing a seal against by-pass liquid flow through the ~ groove^__the tip portion of the porous member being deflectable in a predetermined direction whereby to break the seal. 2. An applicator according to claim 1, wherein the porous member is such as to permit capillary flow of the liquid. 3. An applicator according to claim 1, wherein an outer end of the groove is adjacent to but spaced from the mouth of the enclosure whereby to define a sealing land on the enclosure wall against which the tip portion normally seals whereby to prevent said by-pass liquid flow. 4. An applicator according to claim 3, wherein the mouth:-of the enclosure is inclined at an acute angle to the axis of the enclosure whereby to permit deflection of the tip portion preferentially in said predetermined direction. 5. A liquid applicator according to claim 1, wherein the enclosure comprises a cup having a base adapted to communicate with the interior of the liquid container, and the groove extends from the base portion of the cup to a position adjacent the mouth of the cup. 6. A liquid applicator according to claim 4, wherein the enclosure comprises.a cup having a base adapted to communicate with the interior of the liquid container, and the groove extends from the base portion of the cup to a position adjacent the mouth of the cup. 7. An applicator according, to claim 1, wherein .the porous member is of substantially elongate rectangular cross section, with the shorter sides of the cross section being oriented in said predetermined direction. 8. An applicator according to claim 6, wherein the porous member is of substantially elongate rectangular cross section, with the shorter sides of the cross section being oriented in said predetermined direction. 9. An applicator according to claim 4, wherein the porous member is held under compression in the enclosure. 10. An applicator according to claim 1, in combination with a removable lid operative to enclose the exposed tip portion of the applicator, said lid including sealing means which co-operates with the applicator to define a small volume liquid-tight sealed chamber in which the exposed tip portion lies. 11. An applicator according to claim 1 in combination with a liquid container. 12. A shoe polish applicator comprising an applicator according to claim 1 mounted on the neck portion of a container for liquid shoe polish, the enclosure projecting upwardly from the neck portion.

Inventors: FOX JAMES CHARLES, FOX, JAMES, CHARLES
Applicants: NICHOLAS KIWI PACIFIC PTY LTD, NICHOLAS KIWI (PACIFIC) PTY. LTD.
Application year: 1985
Main classification: B65D47
IPC codes: A47L23, B65D47