Diffuser of evaporable substances with improved Anti-removal wick

Abstract

A diffuser of evaporable substances comprises a plug (P) having a wick-holder passage equipped with retaining means (4, 5) for a wick (W). The lateral surface of the wick (W) is provided with one or more recesses, in the form of perimetral cuts (1) in the external covering (2) of said wick (W), within which said retaining means (4, 5) of the wick-holder passage engage during an extraction movement of the wick (W) from said wick-holder passage, to block the wick (W) and prevent its extraction from said wick-holder passage.

Description

[0001] DIFFUSER OF EVAPORABLE SUBSTANCES WITH IMPROVED ANTI-REMOVAL WICK

[0002] DESCRIPTION

[0003] FIELD OF INVENTION

[0004] The present invention relates to the field of diffusers or emanators of evaporable substances such as fragrances and / or insecticides . In particular, the invention relates to a wick-type dif fuser, provided with an improved anti-removal wick .

[0005] STATE OF THE PRIOR ART

[0006] Diffusers ( or emanators ) are devices widely available on the market and known for many years , which diffuse into the surrounding environment liquid evaporable substances , such as room fragrances or insecticides , contained in a portion of the device acting as a container of such substances . In the dif fusers which the present invention is addressed to, the evaporable substances are diffused by means of a wick, one end of which is conveniently dipped into the bottom of the container of evaporable substances , while the opposite end emerges from said container, through a plug which encloses the wick in a sealed manner, thus being in contact with the ambient air to obtain the desired evaporation ef fect . A container of this type , which is widely available on the market , generally has the shape of a bottle with a neck, and said plug allows therefore a dual sealed connection both between the bottle neck and the plug and between the plug and the wick . The evaporable substance diffusion is therefore mediated by a wick - which absorbs the evaporable substance from the container through its internal end and conveys it in the liquid state , by capillary effect , towards the external end from which this substance dif fuses in the vapour state - and can be accelerated by a ventilation or heating action targeting the wick external end .

[0007] Among the various problems pertaining to the construction of dif fusers , there is also the protection against access to the tank containing the liquid evaporable substances . In particular, such access must be prevented for at least two main reasons : first , and most important , to prevent users , especially children, from easily extracting the wick from the diffuser and thus coming into contact with the liquid evaporable substances ; second, to prevent users from refilling the tank with non-original evaporable substances - when the initial charge is depleted - which substances presumably have not been previously validated for operation on that specific type of dif fuser and can therefore give rise to the release of uncontrolled amounts of evaporable substances into the environment , or cause other types of malfunctions of the diffuser itself , not excluding for example a fire hazard . In some cases , as that of diffusers containing insecticidal substances , the evaporable substances can cause health or ecological problems if accidentally ingested or released into the environment , which is why in these cases there is even an increased concern about avoiding any possibility that the tank liquid contents could be spilled into the external environment upon accidental removal of the wick .

[0008] In order to achieve the obj ect of keeping the liquid in the container of evaporable substances completely isolated from the external environment , not only the bottle plug needs to be fixed to the bottle neck in a not easily removable way, but also the wick must remain permanently blocked inside the wick-holder passage provided in the plug, so that it cannot be either accidentally or voluntarily removed without leaving a very obvious sign of tampering, such as , for example, a wick breakage, which can adequately alert users of the occurred tampering .

[0009] To solve the above-described problem, many different solutions have been proposed over time, which include, by way of example , those disclosed by patents ES 2 137 108 , US 6 236 807 , US 6 354 513 , US 6 619 560 , and US 2008 / 0093475 .

[0010] ES 2 137 108 ( 1999 ) discloses a shutter device for a dif fuser of evaporable substances , consisting of a cylindrical body of plastic material equipped with stable means for mounting on the corresponding neck of the dif fuser . Such cylindrical body has a concentric axial passage to house a wick . The wick is then fixed in place by a compressive action exerted by the axial passage when this latter is deformed inwards by means of external flaps pro jecting from the body of the shutter device . Said flaps can in fact be moved from an upper non-working position to a lower position wherein they radially protrude inwards , narrowing the passage and thus fixing the wick in place inside the same .

[0011] US 6 236 807 ( 2001 ) discloses a liquid diffuser equipped with a wick and containing a liquid to be evaporated with the aid of heat . A retaining plug is inserted into a neck of the dif fuser; the retaining plug has an axial passage for housing a wick; the lower portion of said wick extends downward into the container body to absorb liquid from the container . Immediately below said axial passage of the retaining plug, the wick is provided with a through steel pin which prevents the removal of the wick by abutting against the retaining plug .

[0012] US 6 354 513 ( 2002 ) discloses a plug for containers containing evaporable liquids . The plug consists of a body permanently coupled to the neck of the liquid dif fuser, and a wick axially coupled in a concentric passage of the plug itself . An inner portion of the axial passage of the plug wherein the wick is inserted is provided with longitudinal slots separating adj acent sectors , each provided with a semi-pyramidal pro jection . The plurality of semi-pyramidal pro j ections allows the wick to move in the direction of insertion but blocks its movement in the opposite direction towards the outside, thus preventing the wick from being removed from the plug .

[0013] US 6 , 619 , 560 ( 2003 ) discloses a diffuser of evaporable substances having a neck into which a wick-holder assembly provided with a passage formed therethrough housing a wick is press-fitted and snap-locked, said passage being provided with at least two opposing fingers . Each of the fingers has an internal surface defining part of the passage of the wick-holder and an external surface , a sealing ring being further provided on the external surfaces of the two fingers to thereby compress the wick between them .

[0014] US 2008 / 0093475 discloses a diffuser of evaporable substances having a neck into which a wick-holder assembly provided with a passage formed therethrough housing a wick is press-fitted and snap-locked . A slot is formed in the lower portion of the wick, which thus forms a retaining element which gets caught on the wick-housing passage to prevent removal of the wick from the container .

[0015] From the above illustrated state of the art , it clearly appears that all the cited known devices disclose rather complicated structures of plugs , which are therefore more expensive to manufacture, or require a modification of the wick - as disclosed in patents ' 807 and ' 475 - an intervention which complicates assembly, thus lengthening production times and impairing the wick mechanical resistance . Furthermore, apart from the two patents indicated above , the other devices aimed to prevent the removal of the wick exclusively rely on increasing the friction force between the wick surface and the wick-housing passage formed in the diffuser closing plug . However, these devices have been found ineffective in preventing the removal of wicks having a smooth or very smooth external surface, or of wicks made by compliant material which therefore easily lose their own proper shape under pressure without determining a high friction resistance .

[0016] PROBLEM AND SOLUTION

[0017] The technical problem underlying the invention is therefore that of providing a diffuser of evaporable substances equipped with an anti-removal wick, which does not suf fer from the above- mentioned drawbacks , and, in particular, a dif fuser which does not require complicated structures of the wick-holder passage inside the plug to increase the friction resistance with the wick, or modifications to the wick during assembly of the dif fuser .

[0018] In the context of this technical problem, it is an obj ect of the present invention to provide a modified wick which can be easily blocked in the wick-holder passage of a plug, in the event of attempted extraction therefrom, regardless of the roughness degree of the wick external surface, or of the compliance degree of the material which the wick is made from .

[0019] A further ob ject of the present invention is to provide a modified wick which can be easily blocked in the wick-holder passage of a plug, in the event of attempted extraction therefrom, without any modification of the structure of the wick after its manufacture and without deteriorating its mechanical resistance .

[0020] This ob ject is achieved, and the related technical problem solved, by a diffuser of evaporable substances having the features defined in claim 1 . The dependent claims describe other preferred features of the invention . US 2008 / 0093475 is the prior art document closest to the present invention and its related features are reported in the preamble of the main claim . BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Further features and advantages of the diffuser of evaporable substances of the present invention will anyhow become more evident from the following detailed description of preferred embodiments of the same , given by mere way of non-limiting example and illustrated in the accompanying drawings , wherein :

[0022] Fig . 1A is a front , axial cross-section view of a plug for a dif fuser of evaporable substances , wherein an anti-removal wick according to a first embodiment of the present invention is inserted in its normal working position;

[0023] Fig . IB is a view similar to Fig . 1A, after an attempt to extract the wick in the direction indicated by the arrow;

[0024] Fig . 2A is a front , axial cross-section view of a plug for a dif fuser of evaporable substances , wherein an anti-removal wick according with a second embodiment of the present invention is inserted; and

[0025] Fig . 2B is a view similar to Fig . 2A, after an attempt to extract the wick in the direction indicated by the arrow . DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0026] According to the present invention, to overcome the above- mentioned drawbacks of the known dif fusers , it has been envisaged to improve the interaction between a wick and the walls delimiting a wick-holder passage formed in the plug of the container of evaporable substances wherein the wick is housed . Such modification only concerns the external surface of the wick, wherein one or more recesses are provided, with which the end edge of the wick-holder passage walls engages , when an attempt to extract the wick from the plug is made , thus preventing its removal .

[0027] Referring to the first embodiment of the invention, illustrated in Figs . 1A and IB, and according to a construction forming part of the known art , a wick W is housed inside a corresponding wick-holder passage of a plug P of a container of liquid evaporable substances (not illustrated) associated with a device for diffusing such substances . Most commonly, the wick W has a circular cross-section; however, the solution of the present invention can be implemented with wicks having a cross-section of another shape as well, such as for example a squared or polygonal shape .

[0028] In the present invention, a two-component wick W is used, i . e . , a wick comprising a core portion (or inner portion) and an external covering (or skin) . The core portion may consist of a bundle of wicks simply juxtaposed or partially joined together by a physical process . Alternatively, the core portion may be composed of a fine particulate of plastic materials subj ected to a sintering process .

[0029] The external covering is preferably formed by at least one layer of a material which is porous or in any case permeable to evaporable substances . Preferably, the external covering is thin, for example , weighting 40-120 g / m2and being made of paper or textile material , in which latter case it is preferably a nonwoven fabric . The external covering can be simply wrapped around and in contact with the core portion, i . e . , without the use of any means of mutual bonding; alternatively, the external covering can be joined to the core portion using adhesives , or by any other known means .

[0030] Still referring to Fig . 1A, the plug P comprises a shoulder S which is stably fixed to the neck of said container of evaporable substances in a manner known per se , for example by means of a rib R which allows the plug P to be snap-locked in a not easily removable manner . Alternatively, the shoulder S can be fixed to the neck of the container of evaporable substances by other means , all well-known per se .

[0031] According to the known art , the wick-holder passage of the plug P , wherein the wick W is housed, is slightly smaller in its cross dimension than the wick W, so that a moderate interference is generated with the internal surface of said passage when the wick W is inserted therein, which interference therefore causes a pre-compression of the wick W - in its area Ws remaining inside the wick-holder passage - which makes it more difficult for the user to extract the wick W, thanks to the greater friction thus generated between these two elements .

[0032] To further increase such friction, the lower end of the walls delimiting the wick-holder passage of the plug P can have a sharp edge 4 in contact with the wick W surface , i . e . , an edge ending with an angle of less than 90 ° and / or comprising other elements of interference with the wick W (not illustrated) , for example in the form of ribs formed on the internal surface of the wick-holder passage of the plug P parallelly to the longitudinal axis of the wick W . Said ribs may also be provided with a hook- or toothshaped end, still for the purpose of increasing friction with the wick W surface, and are also preferably oriented to facilitate the entry of the wick W into the wick-holder passage of the plug P and, on the contrary, hinder its removal , i . e . , gradually increasing their thickness starting from the wick-insertion side, the exit edge of said wick-holder passage of the plug P ending then with an angle of less than 90 ° .

[0033] According to the present invention, along with the above examined teachings of the prior art - all aimed at enhancing the level of friction between the wick W and the walls delimiting the wick-holder passage of the plug P - the interaction between these two elements is additionally radically modified by providing one or more recesses on the lateral surface of the wick W in an area below the lower end of the wick-holder passage of the plug P , in order to avoid, even more safely, a possible extraction of the wick W from the plug P . Thanks to these recesses , when the wick W undergoes an attempt to be extracted from the container, both the end edge of the walls delimiting the wick-holder passage of the plug P , or any other additional elements exerting friction on the wick W, form retaining means of the wick W which engage within said recesses , thus abruptly increasing the force needed to extract the wick W to such an extent as to make it impossible to extract the wick W intact from the plug P . As a matter of fact , by further increasing the extraction force applied to the wick W, the wick W breaking load is exceeded without however being able to remove it intact from the wick-holder passage of the plug P . In this case, in fact , when the wick W breaks , its lower part remains stuck in the terminal part of the wick-holder passage of the plug P , still preventing the user from direct access to the evaporable substance . It should be noted, in this regard, that since the recesses are only formed on the external covering of the wick, the mechanical resistance of the wick body is not impaired and therefore its possible breakage does not occur at the end edge of the wick-holder passage - on which only the wick external covering gets caught - but inside said passage . The favourable consequence is thus determined that the piece of wick not extracted remains firmly stuck in the wick-holder passage rather than falling inside the tank, as instead happens when the recess is in the form of a notch in the wick body as disclosed in the closest known art of the patent ' 475 .

[0034] The drawings illustrate two different embodiments of the invention, wherein a plug P with a wick-holder passage is provided with retaining means comprising a sharp edge 4 facing the wick (Figs . 1 ) and with retaining means comprising a bevelled edge 5 (Figs . 2 ) , respectively, according to a typical structure of standard plugs currently available on the market . In the preferred embodiments illustrated in the drawings , said one or more recesses consist of perimetral cuts 1 in the skin 2 of the wick W . Each perimetral cut 1 preferably goes through the entire thickness of the skin 2 , thus exposing the inner portion 3 of the wick W in front of the walls forming the wick-holder passage of the plug P .

[0035] Figs . 1A and 2A show the normal working position of the wick W, wherein the lower end of the wick-holder passage is positioned just above the cuts 1 , while Figs . IB and 2B show the position of the wick W after an attempt to extract the same from the plug P in the direction of the arrow, where it can be noted that the retaining means of the wick-holder passage engaged within the cuts 1 , thus blocking any further movement of the wick W in the direction of the arrow .

[0036] In the above embodiments , the perimetral cut 1 is preferably partial , i . e . , it is in the shape of a discontinuous line , which therefore does not extend along the entire perimeter of the wick W, so as not to excessively weaken the skin 2 . This measure is necessary above all in the embodiments where the skin 2 is simply resting, without any means of mutual bonding, on the underlying inner portion 3 of the wick W; in this case, in fact , a perimetral complete cut would make it possible the easy breaking and extraction of the skin 2 alone even through a modest force of extraction . In other words , in such embodiments the recesses consist of a plurality of perimetral cuts 1 formed on the same perimeter of the wick W, mutually separated by sections of intact skin 2 . This embodiment is preferred as it allows for a more balanced distribution of the forces applied to the skin 2 by the lower end of the wick-holder passage of the plug P , during an attempt to extract the wick W .

[0037] When the perimetral cut 1 is not continuous , it is however necessary to ensure that the retaining means of the wick-holder passage are effectively aligned with the perimetral cuts 1 when they do not extend along the entire perimeter of the wick-holder passage in order to contact them during an attempt to extract the wick W .

[0038] To achieve such alignment , a first method may be that of inserting elements of correct mutual coupling, both in the wick W and in the wick-holder passage of the plug P , such as for example a longitudinal groove in the wick W and a longitudinal rib in the wick-holder passage of the plug P so that the perimetral cut 1 in the wick W can come into contact with the retaining means of the wick-holder passage when the wick W is pulled upwards . This option leads to a satis factory result but is complicated to implement during manufacture and assembly and is therefore not currently preferred .

[0039] A second, preferred method for obtaining the desired alignment between said retaining means and the perimetral cuts 1 involves instead making several superimposed lines of perimetral cuts 1 (not illustrated in the drawings ) along the entire length of the wick W, each line of cuts being appropriately staggered with respect to the adj acent lines of cuts , so that sooner or later, during the attempted extraction of the wick W, the retaining means will necessarily coincide with one of the perimetral cuts 1 of said superimposed lines of cuts , regardless of which angular orientation the wick W has been inserted with into the wick-holder passage of the plug P . In this second method, the distance between two superimposed lines of perimetral cuts 1 must be less than the distance between the retaining means of the wick-holder passage and the bottom of the container of evaporable substances , when the plug P is fixed on the neck of said container . In this way, it is certain that there will always be at least two partially superimposed lines of perimetral cuts 1 below said retaining means .

[0040] To reduce the range of movement of the wick W before the blocking action described above takes place during an extraction attempt , it is advisable to narrow the distance between the superimposed lines of perimetral cuts 1 along the length of the wick W . As a matter fact , the greater the number of lines of cuts 1 , the smaller the distance by which the wick can be moved - in an extraction attempt - before said retaining means engage within one of the perimetral cuts 1 . However, this will also lead to a higher impact on the reduction of mechanical resistance of the wick skin 2 . Hence , it is necessary to optimise the distance between the superimposed lines of perimetral cuts 1 as a function of the mechanical features of the wick W to obtain the shortest possible extraction stroke while maintaining a satis factory mechanical resistance of the wick skin 2 .

[0041] Furthermore, this second method of implementing the perimetral cuts 1 is very suitable for the wick manufacturing process which is currently most widely used by manufacturers . In said process , wicks are in fact manufactured in a cylindrical shape , given that such shape is the simplest to be produced and assembled, as it does not request any specific orientation to be respected . This type of cylindrical wick is made in a continuous process , wherein all the wick components are assembled in a flow, resulting in a long, continuous wick, which is then cut into separate individual wicks of the desired length . With this type of process , characterised by an extremely high productivity, it would therefore be rather problematic to insert one or more perimetral cuts on the external covering of the wick, both in a radially and longitudinally predetermined position so that it coincides with said retaining means . On the contrary, the above method which provides for perimetral cuts along the entire length of the wick solves any alignment problem and also allows for the perimetral cuts to be made on the wick skin 2 before it is wrapped around the wick inner portion 3 , thus carrying out this operation with much more ease on a flat surface rather than on the cylindrical surface of the already formed wick W .

[0042] For example, for a cylindrical wick W having a length of 70 mm and a diameter of 6 . 7 mm, discontinuous recesses can be obtained by means of a sequence of superimposed lines of perimetral cuts 1 , each comprising 4 cuts of 3 mm in length, separated by a section of intact skin 2 of approximately 2 mm; this type of line of cuts can be repeated several times , in an appropriately staggered manner, at a distance of 3 mm from one another along the entire length of the wick, thus obtaining 23 lines of cuts per wick . In this example , the wick W can therefore be moved, in an extraction attempt , from a minimum of 3 mm to a maximum of 6 mm before it is blocked by the retaining means of the wick-holder passage which engage within a perimetral cut 1 , depending on whether the engagement already occurs on the first line of cuts 1 or on the immediately following one .

[0043] In a dif ferent arrangement of the above-mentioned recesses , only two perimetral cuts 1 are provided, located under the retaining means at dif ferent heights of the wick W, and said perimetral cuts 1 as a whole must cover the entire circumference of the wick W with also sufficient mutual superimposition at their ends , so that said retaining means must necessarily engage within one or the other of said perimetral cuts , preventing the wick W extraction .

[0044] With regard to the orientation of the perimetral cuts 1 , i . e . , the inclination of the plane wherein they lie with respect to the longitudinal axis of the wick W, the preferred direction is perpendicular to such axis , since a configuration of this type offers the maximum resistance with respect to the movements of the wick in the longitudinal direction of extraction . However, if for some reason it were more convenient to make the perimetral cuts 1 with a moderate inclination with respect to the above said direction perpendicular to the axis , the ob jectives of the invention would still be achieved .

[0045] From the preceding description it should be clear how a dif fuser of evaporable substances according to the present invention, comprising a plug P , a wick-holder passage formed in the plug P and equipped with retaining means of a wick W housed therein, wherein said wick W has at least one recess on its external covering 2 , has fully achieved the obj ects of the invention . AS a matter of fact , the engagement of the retaining means within said recess ( es ) blocks the wick with an additional force over the ordinary friction force, preventing the extraction of the same from its seat , regardless of the roughness degree of the wick external surface or the yielding degree of the material which the wick is made from . Furthermore, since the cuts 1 are only formed in the wick skin 2 , the mechanical resistance of the wick body is not impaired and, furthermore , the implementation of the cuts on the skin 2 can be carried out during manufacturing of said skin 2 , and not on the already finished wick, thus considerably simplifying such operation .

[0046] However, it is understood that the invention is not to be considered as limited to the specific arrangements illustrated above , which are only exemplary embodiments thereof , but that dif ferent variants are possible, all within the reach of a person skilled in the art , without thereby departing from the scope of protection of the invention itself , as defined by the following claims .

Claims

CLAIMS1) Diffuser of evaporable substances, comprising a plug (P) having a wick-holder passage equipped with retaining means (4, 5) for a wick (W) , and a wick (W) housed in said wick-holder passage, wherein the lateral surface of said wick (W) is provided with one or more recesses within which said retaining means (4, 5) of the wick-holder passage engage during an extraction movement of the wick (W) from said wick-holder passage, to block the wick (W) and prevent its extraction from said wick-holder passage, characterised in that said wick (W) includes a core portion (3) wrapped by an external covering (2) of a porous material and in that said one or more recesses consist of perimetral cuts (1) formed in said external covering (2) .2) Diffuser of evaporable substances according to claim 1, wherein said perimetral cuts (1) go through the entire thickness of said external covering (2) .3) Diffuser of evaporable substances according to claim 2, wherein said perimetral cuts are arranged along a line of cuts, separated by sections of said intact external covering (2) , said line of cuts extending along the entire perimeter of the wick (W) .4) Diffuser of evaporable substances according to claim 3, comprising a mutually parallel and superimposed plurality of said lines of cuts, which are evenly spread over the entire surface of the external covering (2) of said wick (W) .5) Diffuser of evaporable substances according to claim 4, wherein the perimetral cuts (1) of one of said lines of cuts are staggered with respect to the perimetral cuts (1) of the adjacent lines of cuts.6) Diffuser of evaporable substances according to claim 3, comprising two superimposed lines of cuts, each of said lines of cuts comprising a single perimetral cut (1) , the perimetral cuts (1) of said two superimposed lines of cuts covering the entire perimeter of the wick (W) with mutual superimposition at their ends .7) Diffuser of evaporable substances according to any oneof the preceding claims 3 to 6 , wherein said lines of cuts lie in a plane perpendicular to the longitudinal axis of the wick (W) .8 ) Dif fuser of evaporable substances according to any one of the preceding claims , wherein said retaining means of the wick- holder passage of the plug (P ) engage within said wick (W) with one of their edges ( 4 ) .

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