The present invention relates to applicators for liquids. In particular, the present invention relates to applicators for liquids such as glues which include a volatile constituent, however, the present invention is not limited thereto.

BACKGROUND OF THE INVENTION

The present invention is particularly useful for glues used to seal PVC plumbing fixtures where the glue, normally coloured blue, includes a highly volatile organic solvent such as Methyl Ethyl Ketone. At present such glues are sold in small pots, having a screw cap with an applicator formed on the inside of the cap. The applicator can be either a bundle of hairs forming a brush or a swab formed by a piece of porous material such as a sponge held in a support formed by a looped and twisted piece of wire. In either of these circumstances, the glue adheres to the brush or swab and is then wiped onto the PVC services to be joined. A fundamental problem with such applicators is that the hairs of the brush or the swab do not reach to the bottom of the container and thus it is difficult to fully utilise all the contents of the container. US Patents Nos. 3,992,116 and 4,917,520 are illustrative of this art.

Furthermore, during the application procedure, the container is entirely open and thus the large surface area of the glue within the container is exposed to the atmosphere resulting in a substantial escape of the volatile constituent. As a consequence, repeated use of the applicator causes the glue to become increasingly viscose. As a result, if the entire contents of the glue container are not used within a short period of time, the remaining contents left within the container often become too viscose to be used, or used effectively.

Another prior art glue is PVA woodworking glue. This glue is traditionally stored in a flexible plastic container having a capped spout. In order to apply the glue the cap is removed from the spout and the container squeezed so as to eject the liquid glue from the spout directly onto the surface to which it is desired to apply the glue.

Such containers suffer from the problem that the glue to some extent fouls the outer

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surface of the spout. Thus the cap when re-applied does not perfectly seal the container.

OBJECT OF THE INVENTION The genesis of the present invention is a desire to address the abovementioned problems.

DISCLOSURE OF THE INVENTION

In accordance with a first aspect of the present invention there is disclosed a liquid applicator for glues and the like, said applicator comprising a closed reservoir, an applicator tube extending from said reservoir, a liquid permeable cover for said applicator tube, a removable cap to enclose said cover, said cover being in liquid communication with the interior of said applicator tube, and a return passage interconnecting said cover and reservoir.

In accordance with the second aspect of the present invention there is disclosed a method of storing and applying liquids such as glues, and the like, said method comprising the steps of:

(i) maintaining said liquid in a closed reservoir; (ii) when required, releasing said liquid into an applicator tube having a liquid permeable cover in liquid communication with the interior of said applicator tube;

(iii) removing a cap which encloses said cover;

(iv) applying said liquid impregnated cover to the surface(s) to which said liquid is to be applied;

(v) replacing said cap, and

(vi) providing a return passage between said cap enclosed cover and said reservoir whereby volatile constituents of said liquid can impregnate said cover.

BRIEF DESCRIPTION OF THE DRAWINGS

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Several embodiments of the present invention will now be described with reference to the drawings in which:

Fig. 1 is a perspective view of an applicator of a first embodiment, Fig. 2 is an exploded perspective view of the applicator of Fig. 1 except for the body of the reservoir,

Fig. 3 is a longitudinal cross-sectional view through the upper portion of the applicator of Fig. 1,

Fig. 4 is a perspective view of the applicator of Fig. 1 showing its cap removed and the pump being operated,

Fig. 5 is a perspective view of the applicator of Fig. 1, showing the application of the glue to a surface,

Figs. 6-8 are views similar to Figs. 1-3 but illustrating an applicator of a second embodiment, Fig. 9 is a perspective view of the applicator of a third embodiment,

Fig. 10 is a longitudinal cross-sectional view of the applicator of Fig. 9, Fig. 11 is an exploded perspective view of the applicator of Fig. 9 except for the body of the reservoir,

Fig. 12 is a perspective view of an applicator of a fourth embodiment, Fig. 13 is a longitudinal cross-sectional view of the applicator of Fig. 12,

Fig. 14 is an exploded perspective view of the applicator of Fig. 12 except for the body of the reservoir, and

Fig. 15 is a perspective view of the applicator of Fig. 12 showing its cap removed and ready for the application of the glue to a surface.

DETAILED DESCRIPTION OF THE INVENTION

As seen in Figs 1-3, the applicator 1 of the first embodiment has a reservoir 2 having a screw top 3 which includes a sleeve 4, a cap 5 and a pump 6. As best seen in Fig. 2, the pump 6 has an inlet 7 and a handle 8 which connects with a plunger 9.

As seen in Fig 3, the pump 6 has an outlet 12 which leads into a hollow stem 13 which in turn leads into the interior of an applicator tube 14 which is provided with

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numerous perforations 15. The sleeve 14 is co-axial with the stem 13 and surrounds it so as to form a passageway which interconnects the interior 17 and the interior 18 of the cap 5. As seen in Fig. 3, the sleeve 4 is provided with a funnel-shaped rim 24 which provides a substantially fluid tight frictional seal with the cap 5.

The applicator tube 14 is surrounded with a cover 20 which is shaped like the finger of a glove and which is formed from liquid permeable material. The preferred material from which the cover 20 is fabricated is a plastics foam type material such as polypropylene. .

Within the pump 6 are two valves 26 and 27 which respectively contain spring biased balls 28 and 29. The handle 8 of the plunger 9 is moved up and down so as to reciprocate the plunger 9. When the plunger 9 is drawn upwardly, a low pressure is created within the interior of the pump 6 thereby closing the valve 27 and opening the valve 26 to permit liquid from within the reservoir 2 to pass into the interior of the pump 6. Conversely, when the plunger 9 is moved downwardly in Fig. 3, the valve 26 shuts as the pressure within the pump 6 increases and the valve 27 opens thereby permitting liquid to pass through the valve outlet 12 and into the stem 13 and thus into the applicator tube 14. Such liquid then passes through the permeable cover 20 and is available for application. Any excess liquid runs into the funnel-shaped rim 24 and returns to the reservoir 2 via the hollow sleeve 4. This manual reciprocation of the plunger 9 is schematically illustrated in Fig. 4 and the application of the liquid glue from the cover 20 onto the surface where it is desired is illustrated in Fig. 5.

A number of important consequences flow from the above-described construction. Firstly, the body of liquid within the reservoir 2 is never open to the atmosphere so volatile constituents in the liquid glue are unable to readily evaporate. Secondly, the operation is one handed as opposed to the conventional applicator brash or swab which requires a two-handed operation in which one hand holds the body of the container whilst the other hand unscrews or dips the applicator brash or swab into the liquid. As a consequence, the applicator illustrated in Figs. 1-5 can be used in

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awkward positions, such as up a ladder or with the arm holding the applicator outstretched.

Furthermore, because the cap 5 forms a fluid tight seal as a result of a friction fit between the cap 5 and the rim 24, the sealing surfaces of which are free of any liquid glue, not only does any excess liquid drain from the rim 24 into the reservoir 2, but volatile vapours from the reservoir interior 17 can pass through the hollow sleeve

4 and into the interior 18 of the cap 5 thereby preventing the liquid glue which remains impregnated in the cover 20 from setting, or otherwise going hard or becoming increasingly viscous. As a consequence, the liquid glue within the reservoir

2 can be stored therein for long periods of time without any deterioration.

Figs. 6-8 illustrate a second embodiment of the present invention in which the inlet 107 of the pump 106, and the pump 106 itself, are slightly differently configured. Otherwise the embodiment of Figs 6-8 is substantially similar to that of Figs 1-3.

Figs. 9 - 11 illustrate a third embodiment of the present invention in which the pump 206, inlet 207 of the pump 206, the pump outlet 212, the hollow stem 213 are located in a body 204 screwed onto the reservoir. The pump 206 is operated by pushing on a pivoted button 209 and operates in a similar manner to the two previously described embodiments.

A further embodiment of the present invention is illustrated in Figs. 12-15.

This embodiment of the applicator does not include a pump but operates by gravity as the liquid flows into the stem 313 when the applicator is turned upside down as seen in Fig. 15. The applicator is substantially similar to the other embodiments except for the lack of a pump and plunger.

The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the plumbing arts, can be made thereto without departing from the scope of the present invention. For example, although the

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screw top 3 is preferably made from metal and the reservoir 2 from plastics, if desired the entire structure can be fabricated from plastics.

The term "comprising" (and its grammatical variations) as used herein is used in the inclusive sense of "including" or "having" and not in the exclusive sense of "consisting only of.

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