WO2016120336A1

WO2016120336A1 - Aerosol spray can with unidirectional movement activation device and method of manufacture of such an aerosol spray can

Info

Publication number: WO2016120336A1
Application number: PCT/EP2016/051717
Authority: WO
Inventors: Rudi LETEN
Original assignee: Soudal
Priority date: 2015-01-28
Filing date: 2016-01-27
Publication date: 2016-08-04
Also published as: RU2017129395A; RU2692992C9; EP3250478B1; PL3250478T3; BE1023387A1; RU2692992C2; ITMI20150015U1; HUE051149T2; EP3250478A1; SI3250478T1; BE1023387B1; RU2017129395A3

Abstract

Aerosol spray can with unidirectional movement activation device Aerosol can (10) comprising a can body (12) in which a cartridge (14) is coaxially inserted and stabilized, which is coupled with an activation device or throttle lever (16) housed in a recessed portion (18) of a face of the body (12) from which the cartridge protrudes with a shaped appendix (20) forming the shank for the connection to the throttle lever (16); the lever defining, in the central part, a circular core (22)forming a circular mouth (30) starting from a circular crown (28). The core is provided with a series of shaped recesses (26) extending at least partly circumferentially along the internal side surface (26)' of the core and are intended to cooperate with complementary protrusions (36) extending on at least one part of the circumference of a bush (32). The bush is engaged in the circular mouth (30) and is connected to the shaped appendix (20).

Description

AEROSOL SPRAY CAN WITH UNIDIRECTIONAL MOVEMENT ACTIVATION DEVICE AND METHOD OF MANUFACTURE OF SUCH AN AEROSOL SPRAY CAN

FIELD OF THE INVENTION

The present invention relates to an aerosol spray can with unidirectional movement activation device. More specifically, this finding relates to an aerosol spray can or pressure can in which two different components, which are kept separate from each other, are inserted, and these two different components are to be mixed only upon imminent subsequent use to obtain and dispense the desired substance. The mixing is activated by means of the rotation of an activation device or a throttle lever.

BACKGROUND OF THE INVENTION

Aerosol spray canisters or cans of this type, which are often defined as two-component cans or 2K cans. They are known and used for example in the sector of cosmetics, paints, lubricants, polyurethane foam compositions, and in the industrial sector in general.

Aerosol cans are usually made of sheet metal and typically have a concave bottom or back face and a convex head or top face, both of which typically being flanged on the opposite sides of the cylindrical can body. The bottom or back face of the can is made concave in order to withstand the pressure inside the can. The concave bottom also makes it easier to put the can with its back face on a substantially flat surface, in an upright position. The head is made convex for the same pressure resistance reason, and typically is provided with a central opening. The opening is for filling the container, after which the container valve is installed by crimping the valve cup into the opening, thereby closing off the container or can. Propellants may still be added subsequently, by pushing them through the valve. The convexity of the head allows for easy access to the container valve, for instance for installing an adapter.

The concave bottom brings yet another advantage. If the pressure in the can exceeds the prescribed level, the bottom concavity is supposed to yield as the weakest part and reverse into a convex bottom or back face, usually making a clear and loud noise. This action significantly increases the internal volume of the can, resulting in an immediate reduction of the pressure inside the expanded can. A further advantage is, when the can is standing upright on a flat surface, such as on a shop shelf, that the expanded can itself is lifted up and also cannot anymore maintain its stable upright position. The expanded and thus failed can may therefore readily be spotted in a group of similar cans, so that appropriate action may be taken by an operator or guard.

Characteristic for the 2K type cans is that the second component is kept in a separate cartridge, inside the larger container containing the first component. Shortly before its intended first use, the cartridge is to be opened towards the container content, by an action from outside the container, and the two components are allowed to mix, usually assisted by the user shaking the container. In many cases a chemical reaction takes place between particular ingredients in the two components, forming the single mixed composition which is desired and ready for being dispensed from the container by again an action by the user on the container valve.

An example is found in polyurethane foam forming compositions, where the first (or "A") component is supplied in a first container and usually contains a prepolymer with remaining isocyanate functionality, while the second (or "B") component is supplied from a second container and contains a hardener, i.e. a polyfunctional isocyanate reactive compound, typically a low molecular weight polyol, preferably having primary alcohol functions. Typically the second component also contains a catalyst for the reaction between isocyanate and polyol, usually a tertiary amine. At the moment of application, the two components are mixed and the resulting mixture is applied to the desired location. The result is a very fast curing mixture forming a high density product with high mechanical properties, very suitable in the construction industry, such as for mounting doors and window frames. Optionally some water may be added to the polyol, which causes C0₂ to form, and in which case propellants may not be essential in order to obtain a foam. For expert professionals and intensive users, usually in a workshop environment, it is common to supply the two components in two separate pressure containers. The system of the two pressure containers and the mixing and application equipment is considered in the industry as being "the pure 2K delivery system".

For less experienced and/or less intensive users, and in particular for improved convenience in a construction site environment, a variant of the 2K delivery system has been developed wherein the second component is contained in a cartridge internal to the container containing the first component. In order to differentiate this version from the "pure 2K" system above, such delivery systems are sometimes addressed as 1 .5K or 1 ½ K PU cans, e.g. in Fig 1 on page 13 of "The Foam Manual" by A. De Schrijver, first published in 1986. For sake of simplicity, this document will stick to the term 2K cans or two-component cans for addressing these type of cans comprising an internal cartridge for the second component.

The two components contained in the 2K cans are isolated from each other in sealed independent enclosures; one of them being integrated in an internal cartridge, typically of cylindrical shape, which, during the assembly of the set, is placed coaxially into the can with respect to which it is stabilized in any known way. Such 2K cans have become widely known for several decades now. Suitable cans have for instance been described in EP 42128, WO 84/01355 and WO 85/00157.

The internal cartridge of such cans is provided with an activation device, usually in the form of a throttle lever, which protrudes from the back face or bottom of the canister or can. The throttle lever may be operated manually by the user, typically by rotation, to activate the cartridge valve, which opens the cartridge at the moment in which it becomes necessary to mix the two components. After the mixing, the operator may dispense or spray, by pressing any conventional dispensing valve installed as the container valve, the composition which has formed as a consequence of the mixing, in the direction of or directly at his target.

An embodiment is also known, as described in Italian utility model ITMI2012000421 , which published under no. IT-U-278.593, in which the activation element or device of the cartridge or throttle lever is arranged in such a way that it fits entirely into the bottom cavity and does not protrude downwards from the back face of the can body, beyond the rim of the bottom flange. This prevents involuntary impacts and movements of the device itself which may possibly lead to damage of the can as a whole. Moreover, this type of can may be placed in a stable way on any substantially flat surface, because the activation device does not protrude even by a minimum amount from the lower face of the can. A further advantage is that the bottom cavity with the throttle lever may be closed off by means of a simple flat flexible casing, e.g. fitting over the bottom flange of the container, and leaving in the cavity sufficient extra room for an accessory object, such as a pair of folded disposable gloves of polymeric material.

Another embodiment referring to two-component cans of the present concern is described in ITMI2013000396, which published under no. IT-U-280.846. The document describes 1 K as well as 2K cans. In both embodiments the can defines also at the upper end a concave development rather than the conventional convex head, the development being provided with a central opening. In the 2K can embodiment, the opening may be used for the introduction and the stabilization of the cartridge. Therefore, the actuating device of the latter is placed at the upper end of the can body, with respect to which it does not protrude because it is fully housed inside the concavity. The prime aim of this embodiment is to reduce the overall height of the can, in particular when including the usual plastic protection lid which is typically placed on the convex heads of pressure cans for protecting the container valve from damage or unintentional opening. At the same time, the actuating device of the cartridge is conveniently protected inside the concave head of ITMI2013000396, because it does not protrude from the body. In addition, a plastic closing lid of small height is sufficient to create a flat and uniform surface at the upper end, again offering sufficient room for an accessory object such as a pair of folded plastic gloves. In all the considered 2K can embodiments, the actuating device of the cartridge advantageously consists of the throttle lever mentioned before, and which is typically made of plastic material. It was however observed that the movement of the lever or actuating device of the cartridge has an important drawback, which is related to the direction of the rotation manually imposed to it.

In fact, these devices or throttle levers traditionally provide a right-hand or clockwise rotation for achieving the activation of the cartridge; this movement being the more spontaneous and intuitive for most people, except for the left-handed, who are led to automatically try an anti-clockwise rotation. Moreover, also right-handed people may occasionally rotate involuntarily or unintentionally, at least in an initial phase, the throttle lever of such conventional aerosol spray cans in the opposite direction with respect to the one that is traditionally arranged for activating the cartridge.

In both instances, significant damage may occur to the can as a consequence of such a rotation in the wrong direction, usually this rotation being performed with appreciable strength. This may lead to severe damage and may represent a significant safety and/or industrial hygiene hazard. It may happen, for example, that the actuating stem is pulled out of its seat, with the consequent possible leakage of liquid under pressure, which would make the aerosol spray can unusable and could create contact of operator skin and/or eyes with the container content, the latter usually still being chemically reactive.

A further problem with the 2K cans as described above relates to the force that needs to be exerted in order to open the cartridge and thereby allow a mix of the second component from the cartridge with the first component present the container and surrounding the cartridge.

In many conventional 2K cans, a rod extends axially and concentrically through the cartridge over its entire length. The rod projects on the one end through a packing or seal to beyond the cartridge and also beyond the concave surface of the container bottom, and the rod is adapted at that end to connect the throttle lever. The other end of the rod cooperates with an inner cover or lid of the cartridge, in a way by which for instance an axial rotation or axial movement of the rod is able to push the cover away from the cartridge and open the cartridge to the surrounding container contents.

In a fully assembled 2K container in accordance to the present invention, the cover of the cartridge is subject to significant forces increasing the force which is required for pushing away the cover or lid, and thus for opening the cartridge.

One force component is usually due to a pressure difference between the pressure in the container, where the first component resides, and the pressure in the cartridge, where the second component resides. The pressure inside the container may for instance be 6 bar gauge (barg), and may be higher than the pressure inside the cartridge, which may for instance be only 1 barg or even atmospheric, and the pressure difference may thus result in a first and important net force component, the advantage being that this first force component is keeping the cartridge cover in place at the upper end of the cartridge, the drawback being that this first force component needs to be overcome to open the cartridge.

It should further be realized that the pressure inside the cartridge acts on only a part of the underside surface area of the cartridge cover, i.e. the surface area excluding the area occupied by the rod where the rod engages with the cover. A net force on the cover, on top of any pressure difference between the container and the cartridge, is therefore the force corresponding to the pressure in the container which acts on this part of the outer surface of the cover which does not have an equivalent inner surface area of the cover because of the internal rod of the cartridge engaging with the inside of the cover. In other words, because the rod occupies part of the inner surface area of the cover, the inner surface of the cover on which the cartridge pressure acts is lower than the outer surface of the cover, on which the container pressure acts. This difference in action area results in a second net force component pushing the cover onto the cartridge, even in case the pressures in container and cartridge would be equal to each other. The inventors have found that this second net force component may also be of significance relative to the total force which has to be overcome to open the cartridge by pushing the cover up. In order to keep the two components in the aerosol spray can or pressure can separate, typically a seal is provided at the place where the cover of the cartridge engages with the cartridge head or wall. The seal may for instance be a rubber o-ring around the part of the cover which enters into the cartridge. The applicants have observed, when filling the cartridge with the second component, that a small amount of this second component may remain present on the inner surface of the cartridge head or wall where the cover, upon closing the cartridge, engages with the cartridge wall. Later, the space in the container surrounding the cartridge is filled with the first component, and the container is closed off by installing the valve. The first component may then come into contact with the small amount of second component against the inner surface of the cartridge wall. The two components readily react with each other, in many instances forming a cross- linked polymer with strong adhesive power. This adhesive thus glues the cover and/or the o-ring to its surroundings, in particular to the cartridge wall. The adhesive force of this small amount of cross-linked polymer in this location represents a third net force component which has to be overcome to open the cartridge by pushing the cover up.

The aim of the present findings is to prevent the above-mentioned drawbacks.

More specifically, the aim of the present invention is to provide an aerosol spray can of the two-component type, which is intended to prevent any drawback should the user impose to the activation device a rotational movement opposite to that which is intended to achieve the opening of the cartridge and the consequent mixing of the two substances inside the can itself.

A further aim of the present invention is to provide an aerosol spray can of the two-component type in which the opening of the valve of the internal cartridge occurs only following the rotation in the correct direction, that is to say, clockwise, of the respective activation device.

A further aim of the present invention is to provide users with an aerosol spray can of the two-component type, which is intended to ensure a high level of resistance and reliability, and which can also be made easily and economically.

The present invention aims to obviate or at least mitigate the above described problem or problems and/or to provide improvements generally.

SUMMARY OF THE INVENTION

According to the invention, there is provided an aerosol spray can as defined in any of the accompanying claims.

These and other aims are achieved by the aerosol spray can of the two-component type of the present invention according to the main claim.

In an embodiment, the present invention provides for an aerosol spray can or pressure can, specifically of the two-component type, with unidirectional movement activation device of the internal cartridge, comprising a can body in which the cartridge is coaxially inserted and stabilized in a known way, which is coupled with a device for its activation or throttle lever housed in a recessed portion of the upper face or of the lower face of the body from which the cartridge itself protrudes with a shaped appendix forming the tang or shank for the connection to the throttle lever, the latter defining in the central part a circular core from which the two opposing branches of the lever develop, the circular core reducing its internal diameter to form a circular mouth starting from a circular crown, characterised in that the throttle lever, in the central part consisting of the core, is provided with a series of shaped recesses, which extend at least partly circumferentially along the internal side surface of the core and are intended to cooperate with complementary protrusions, which extend on at least one part of the circumference of a bush, engaged in the circular mouth and connected to the shaped appendix of the cartridge.

We have found, with the 2K pressure can in accordance with the present invention, that the opening of the valve or cover of the internal cartridge only occurs as a result of the rotation of the activation device in the correct direction, typically the clockwise direction. When turning the activation device in the correct direction, the protrusions engage with the complementary shaped recesses thereby causing the torque force to be transferred from the core of the activation device onto the bush, and thus further onto the shaped appendix and thus onto the rod. The rotation of the rod then pushes away the cover from the cartridge. On the contrary, when the activation device is rotated in the incorrect direction, the core freely rotates around the bush, and is unable to cause a rotation of the rod.

We have thus found that a rotational movement imposed on the activation device opposite to the direction which is intended to achieve the opening of the valve or cover of the internal cartridge, does not run any risk for damage of the container or for a safety and/or industrial hygiene hazard, such as pulling the rod or actuating stem out of its seat, a damage of the cartridge cover, a leakage of liquid under pressure, as well as a possible contact of user skin and/or eyes with the container content.

A further advantage is that a rotational movement imposed on the activation device opposite to the direction which is intended to achieve the opening of the valve or cover of the cartridge will make some sound, typically a clicking sound. Such a clicking sound is a clear and intuitive audible sign to the user that the movement he has been making will be of no effect. The sound will give the user a fast and clear signal that he should be turning the throttle lever in the opposite direction in order to activate the container. The present invention therefore brings the advantage that the user is quickly informed about his unsuccessful attempt to activate the container, and may thus more quickly make the correct action on the throttle lever and activate the container. The present invention therefore also represents a time saving for the user.

We have further found that the pressure can in accordance to the present invention provides an even higher level of resistance against damage due to wrong manipulation and an even higher reliability of good and flawless operations, as compared to the pressure cans known in the art, and also may be produced easily and economically. In an embodiment, the present invention provides for a process for the production of the can (10) according to any one of the preceding claims, comprising the steps of

• folding a rectangular metal sheet into a cylinder and welding two sides of the metal sheet to form the cylindrical part of the can body (12),

• flanging a concave face to one end of the cylindrical part, thereby forming the recessed portion (18), the face comprising a central opening for receiving a cartridge (14),

• coaxially inserting the cartridge (14) into the opening of the face,

• stabilizing the inserted cartridge to the can body (12), preferably by shrinking a cup which is comprised as part of the cartridge (14) onto the rims of the opening in the face, thereby forming a flange between the internal cartridge (14) and the face of the can body (12), and

• flanging a head to the other end of the cylindrical part, thereby forming the can body (12), the head comprising a central opening for receiving a valve.

The construction and functional characteristics of the aerosol spray can of this finding can be better understood from the following detailed description, in which reference is made to the enclosed drawings which represent a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 schematically shows, in a partial perspective view, the aerosol spray can or pressure can of this invention in which a throttle valve forming the cartridge activation device is, by way of example, embedded in a concavity formed on its upper face.

Figure 2 schematically shows an exploded and partial view of the same aerosol spray can, to highlight the connection between the throttle lever and the cartridge;

Figure 3 schematically shows, in a partial perspective view, the aerosol spray can of this finding in which the throttle valve forming the cartridge activation device is, by way of example, embedded in a concavity formed on its lower face;

Figure 4 schematically shows, in an exploded view, said throttle lever coupled with a complementary bush of connection to the cartridge;

Figure 5 schematically shows, in a view from the internal face, the throttle lever and the bush of figure 4 coupled with each other;

Figure 6 schematically shows, in a partially sectioned side view, the throttle lever and the bush according to the previous figure.

Figure 7 schematically shows, in a partially sectioned side view, an aerosol spray can in accordance with the present invention.

Figure 8 schematically shows a cross section of detail A of Figure 7.

DETAILED DESCRIPTION

The present invention will be described in the following with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. Any drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.

As used herein and in the claims, the terms "comprising" and "including" are inclusive or open-ended and do not exclude additional unrecited elements, compositional components, or method steps. Accordingly, the terms "comprising" and "including" encompass the more restrictive terms "consisting essentially of" and "consisting of."

Unless specified otherwise, all values provided herein include up to and including the endpoints given, and the values of the constituents or components of the compositions are expressed in weight percent or % by weight of each ingredient in the composition.

Additionally, each compound used herein may be discussed interchangeably with respect to its chemical formula, chemical name, abbreviation, etc.

In the context of the present invention, the terms "aerosol spray can", "pressure can" and "pressure container" are used interchangeably, all meaning a metal can which may be put under internal pressure and which may be used for dispensing a variety of products.

Suitable products may have a low viscosity, such as at most 4000 mPa.s at 20°C, preferably at most l OOO mPa.s, more preferably at most 500 mPa.s, even more preferably at most 100 mPa.s, yet more preferably at most 50 mPa.s, preferably at most 10 mPa.s, more preferably at most 5.0 mPa.s, even more preferably at most 1 .50 mPa.s at 20°C, and these low viscosity products may often end up being sprayed, such as a personal deodorant, a perfume, a hair spray, a hair colorant, a water-like or water-based composition, a household product, a cosmetic product, a food product, a decoration product, or a technical product, a cleaning liquid, a lubricating oil, a bactericide, a fungicide, an insecticide, and the like.

Suitable products may alternatively have a high viscosity, such as at least 5.000 mPa.s at 20°C, preferably at least 10.000 mPa.s, more preferably at least 20.000 mPa.s, even more preferably at least 40.000 mPa.s, such as a polyurethane (PU) foam forming composition, a silicone paste, a glue, or combinations thereof.

The internal cartridge of the pressure can may for instance be stabilized or fixed inside the container by bolting the cartridge into an opening in the bottom or top face of the container, such as disclosed in WO 84/01355, by a nut which is screwed over a screw threaded outwardly projecting socket of the cartridge, extending through the opening and being sealed by means of a gasket between the bottom part of the cartridge and the inner surface of the container wall around the opening where the cartridge is being fixed.

In another embodiment, similar to what is disclosed in WO 85/00157 A1 , the cartridge comprises a cup which is crimped or shrunk onto the rims of the opening in the bottom or top surface of the container, suitable provided for forming a flange similar to when a conventional valve is shrunk onto a container head, typically additionally sealed with a sealing compound provided as part of the flange.

In an embodiment of the aerosol spray can or pressure can in accordance with the present invention, the internal cartridge comprises a longitudinal body which is on one end closed off with a detachable lid or cover and on the other end is connected to the upper face or the lower or back face of the can, the cartridge further comprising a rod positioned inside the longitudinal body and extending through the entire length of the cartridge, the rod comprising an upper end arranged for being in loose engagement with an inner surface of the cover and a bottom end projecting beyond the upper face or the lower or back face of the can body, forming the shaped appendix (20) which is arranged for coupling with the activation device (16).

In an embodiment of the can in accordance with the present invention, a first elastic ring is provided between the cartridge cover and the cartridge body, which elastic ring is adapted for providing a seal between the content of the cartridge and the content of the can outside the internal cartridge.

In the embodiment of the aerosol spray can or pressure can in accordance with the present invention with the rod in the cartridge, the rod extends through the entire length of the cartridge axially and concentrically relative to the cartridge body.

In the embodiment of the aerosol spray can or pressure can in accordance with the present invention with the rod in the cartridge, the rod is provided with lateral extensions adapted for maintaining the position of the rod relative to a cross section of the cartridge which cross section is taken perpendicular to the central axis of the cartridge body.

In the embodiment of the aerosol spray can or pressure can in accordance with the present invention with the rod in the cartridge, the upper end of the rod comprises an outer screw thread engaging with a corresponding inner screw thread in the cover of the cartridge.

In the embodiment of the aerosol spray can or pressure can in accordance with the present invention with the screw thread engagement between rod and cover, the cartridge body and the cartridge cover are provided with cooperating means preventing the cover from rotating relative to the cartridge. Preferably the longitudinal wall of the cartridge extends for a segment of its circular cross section upward, and the cover has a recess for accepting the cartridge wall extension. Preferably the segmental extension of the longitudinal wall of the cartridge is for a longer distance than the axial contact area between the cover and the cartridge wall. This feature assures that the cover is prevented from rotating relative to the cartridge wall until the cover is pushed entirely free from the cartridge body.

In the embodiment of the aerosol spray can or pressure can in accordance with the present invention with the screw thread engagement between the rod and the cartridge cover, the cartridge cover comprises a tube-shaped extension extending axially from the cover outer surface beyond its inner screw thread, the tube-shaped extension being open at both ends and arranged for cooperating with the upper end of the rod.

The inventors have found that the opening in the cartridge cover acts as a sort of "pressure decompression hole" when the cartridge is being opened. When the rod is being rotated in the correct direction and the cover of the cartridge is being pushed up, the cover needs to move only a small distance before the typically much higher pressure surrounding the cartridge is allowed access to the internals of the cartridge, through the pressure decompression hole. As of that moment, the first net force component as described hereinbefore has removed. Also the second force component as described hereinbefore has been removed. The opening in the cartridge cover through which the rod extension comes into contact with the content of the container outside the cartridge reduces the area of cover outer surface which is subject to the pressure in the container, where the first component resides. For that amount of reduced area, the pressure in the container is, thanks to the present invention of the pressure decompression hole, acting directly on the rod extension and not on the cartridge cover. This brings the benefit that the force needed to push away the cover from the rod and from the cartridge, and thus to open the cartridge, may be further reduced. Preferably the amount of area with which the cover surface is reduced represents at least 40% of the area of the underside of the cartridge cover which is occupied by the rod where the rod engages with the inside of the cover, and where the pressure inside the cartridge cannot act on the inner surface of the cartridge cover. More preferably the amount of area with which the cover surface is reduced represents at least 50%, even more preferably at least 55%, yet more preferably at least 60% of the area of the underside of the cartridge cover which is occupied by the rod. The applicants have found that this feature is able to bring another significant reduction in the total force needed for opening the cartridge. The inventors have further found that this second advantage is already in effect before the rod is rotated, and hence already applies at the first rotational movement given to the rod in the cartridge.

The inventors have found, by providing the pressure decompression hole, that both the first net force component and the second net force component of the force needed to open the cartridge have been removed. The only net force component to overcome in opening the cartridge therefore may be the adhesive power of any cross-linked polymer that has formed as a premature reaction in between the cover, the cartridge wall, and the first o-ring which is providing the seal between the cartridge cover and the wall of the cartridge body.

In the embodiment of the aerosol spray can or pressure can in accordance with the present invention with the screw thread connection between the rod and the cover, the area of the underside of the cartridge cover which is occupied by the rod is calculated as the cross sectional area of the rod where the rod is provided with the external screw thread.

In the embodiment of the aerosol spray can or pressure can in accordance with the present invention with the axial extension of the cartridge cover and of the rod, a recess is provided in at least one axial extension of the cartridge cover and of the rod, and a second elastic ring is provided in the recess and adapted for providing a seal between the content of the cartridge and the content of the can outside the internal cartridge.

The seal between the extension of the cartridge lid and the extension of the rod brings the advantage that the snug fitting between the two extensions is made less critical. This brings the advantage that the two collaborating elements, i.e. the cartridge cover or lid and the rod end, may be fabricated with more tolerance and less precision, such that the production of these elements require less skill and experience. As a result, the elements become more readily available from a higher number of possible sources, and can be offered under more economical conditions.

In an embodiment of the aerosol spray can or pressure can in accordance with the present invention, the recess in the extension of the cartridge or of the rod is circular.

In an embodiment of the aerosol spray can or pressure can in accordance with the present invention, the second elastic ring is made of rubber.

In an embodiment of the aerosol spray can or pressure can in accordance with the present invention, the second elastic ring is an o-ring.

In an embodiment of the process according to the present invention, the process further comprises the step, prior to coaxially inserting the cartridge into the opening of the face, of filling the cartridge with a second component and closing the cartridge with a cover.

In an embodiment of the process according to the present invention, the process further comprises the step of filling the can with a first component and closing the can with a valve, preferably by shrinking a cup which is comprised as part of the valve onto the rim of the opening in the head.

In an embodiment of the process according to the present invention, the process further comprises the step of injecting at least one propellant into the can, preferably injecting the propellant through the valve.

In an embodiment of the process according to the present invention, the process further comprises the step of connecting the bush to the shaped appendix of the cartridge.

In an embodiment of the process according to the present invention, the process further comprises the step of connecting the circular core of the activation device to the bush.

In this document the following reference numbers are used in association with the following corresponding elements:

1 0 aerosol spray can (or pressure can)

1 2 can body

14 internal cartridge

1 6 activation device (or throttle lever)

1 8 recessed portion

20 shaped appendix

22 circular core

24 branch

26 shaped recess (of the core)

26' internal side surface (of the core)

28 circular crown

30 circular mouth

32 bush

34 upper part (of the bush)

36 protrusion

36' external side surface (of the bush)

37 lower part (of the bush)

38 axial through-hole (of the bush)

40 cover (or lid) (of the cartridge) 42 rod

44 lateral extensions (of the rod)

46 cartridge body

48 outer screw thread (on the rod)

50 inner screw thread (in the cover)

52 tube-shaped extension (of the cover)

54 recess (in the rod or in the cover)

56 second elastic ring

58 first elastic ring

With initial reference to figures 1 to 3, the aerosol spray can with unidirectional movement activation device of this finding, indicated as a whole by 10 in figure 1 , comprises a cylindrical can body 12 in which a cartridge 14, which is cylindrical too, is coaxially inserted and stabilized in a known way, said cartridge being coupled with a device for its activation or throttle lever 16. The latter is housed in a recessed portion 18, which can be obtained along the outer face of the body 12, as in figure 1 , or along the opposite lower face, as in figure 3. In both cases, as schematically shown by way of example in figure 2, the cartridge 14 protrudes from said recessed portion 18 with a shaped appendix 20, forming the element for its activation and the tang or shank for the connection to the throttle lever 16.

According to the invention the throttle lever, which in the central part consists of the circular core 22 from which the two opposing branches 24 develop, is provided with a series of shaped recesses 26 having a generally triangular shape, which extend circumferentially along the internal side surface 26' of said core 22, as in figure 4. The recesses 26 are preferably equidistant and made along the entire development of the internal side surface of the core 22, which reduces its internal diameter and forms a circular mouth 30 starting from a circular crown 28; according to the preferred embodiment as in figure 4, the recesses 26 develop in depth into the core 22 until reaching the plane defined by said circular crown 28 and alternate in sections of the side surface 26'.

The throttle lever 16, advantageously made of plastic material, is coupled with a bush 32 made of the same material. The bush 32, shown in detail in the same figure 4 and visible also in figure 2 in the assembly position with the lever 14 on one side and with the appendix 20 of the cartridge 14 on the other side, comprises a substantially cylindrical body with two diameters; the upper part, indicated by 34, defines the smaller diameter, which corresponds to the diameter of the circular mouth 30 of the core 22, except for coupling tolerance. The lower part of the bush 32, indicated by 37, defines a diameter which is appreciably larger with respect to the upper part 34 and is peripherally provided with a plurality of equidistant pointed protrusions 36, shaped in a complementary way and developed in the same direction with respect to the shaped recesses 26 made on the core 22 of the throttle lever 16. The height of said upper part 34 substantially corresponds to that of the internal side surface of the mouth 30 of the core 22, while the diameter of the lower part 32, referred to the side surface without the protrusions 36 and indicated by 36', is equivalent to that of the internal side surface 26' of said core 22, except for coupling tolerance.

The bush 32 is provided with an axial through- hole 38, of quadrangular shape, sized in such a way as to house and stabilize with negative allowance the tang or shank coming out of the cartridge 14, formed by the shaped appendix 20.

As it is disclosed in particular by figure 2, the bush is pressure-fitted onto said shaped appendix 20, which engages in the hole 38; the throttle lever 16 is in its turn fitted onto the bush 32, so that the protrusions 36 of the upper part of the bush 32 arrange themselves in the corresponding shaped recesses 26 of the core 22. This situation of occurred coupling between the bush 32 and throttle lever 16 is noticeable in particular from figure 5, while figures 1 and 2 show, on the opposing branches 24 of the throttle lever 16, arrows indicating the rotational movement to be imposed to the lever to activate the valve of the cartridge 14. Said movement, in this particular case, is performed clockwise and the arrows indicate it. Therefore, it is a rotation suitable above all for the people who usually/mainly use their right hand for the various movements connected with the most variable activities. Any possible accidental rotation imposed specifically by left-handed people in the opposite direction, that is to say, counter-clockwise, would not cause damage in any way, because the throttle lever 16 would rotate in idle state; the pointed protrusions 36 of the bush 32, in fact, would slide along the internal side surface 26' of the core 22 without ever engaging in the shaped recesses 26. This idle rotation is made possible thanks to, and simplified by, the slightest deflection of the plastic material forming said protrusions 36.

It must be considered that this structural setting, with protrusions 36 and corresponding shaped recesses 26, can advantageously be used on any type of two-component or even one- component aerosol spray can of the known type, not only on those which are the object of the above-mentioned exclusive rights of the applicant.

As it can be observed from the above, the advantages achieved by the finding are evident.

In the aerosol spray can of this finding, the presence of the protrusions 36 of the bush 32 and of the complementary shaped recesses 26 created on the core 22 of the throttle lever 16 give rise to an engagement system which allows for the rotation only when the coupling between said two elements has occurred and which also obliges to have the rotation in a given direction, namely clockwise, to obtain the mixing of the two components.

In fact, the possibility of inadvertently rotating the throttle lever 16 in an opposite direction with respect to the planned clockwise direction, without this leading to risks for the integrity or functionality of the aerosol spray can, is particularly advantageous.

In Figure 7 is schematically shown, in a partially sectioned side view, an aerosol spray can 10 in accordance with the present invention. Figure 7 shows how the bottom or back face of the can body 12 is forming a recessed portion 18 having a central opening in which an internal cartridge 14 is stabilized. The cartridge 14 has a cartridge body 46 and is at its upper end closed off by a cover 40. Inside the cartridge 14 is rod 42 extending through the entire length of the cartridge 14. The bottom end of the rod is projecting beyond the back face of the can body and forming the shaped appendix 20. To this shaped appendix 20 is connected the activation device 16, which comprises circular core 22 and opposing branches 24. The activation device and the stabilizing connection between the cartridge 14 and the recessed portion 18 of the can body are only partly cross-sectioned in Figure 7. In figure 7 is indicated a detail A which is shown in Figure 8.

Figure 8 schematically shows a cross section of detail A of Figure 7. Figure 8 shows how the cover 40 is closing off the cartridge by fitting partly inside the cartridge body 46. The cover has a recess in which a first o-ring is provided for forming a seal preventing the content of the cartridge from leaking in between cartridge body and cartridge cover, and possibly coming in contact with the surroundings of the cartridge, as long as the cover is appropriately in place on the cartridge body, as shown in Figure 8.

Figure 8 further shows the engagement between the rod 42 and the cartridge cover 40 in accordance with the present invention. The rod 42 comprises an external screw thread 48 engaging with a corresponding inner screw thread 50 provided as part of the cover 40. The cover 40 has a tube-shaped extension 52 extending axially from the cover outer surface beyond its inner screw thread. The tube-shaped extension is open at both ends, and the upper end of the rod 42 extends into the tube- shaped extension 52 of the cover. The upper end of the rod 42 comprises a circular recess 54 in which fits a second o-ring 56 for forming a seal w2hich prevents the content of the cartridge from leaking in between the upper end of the rod and the tube-shaped extension of the cover, as long as the cover and the rod are appropriately in place, as shown in Figure 8.

Also shown in Figure 8 are lateral extensions 44 provided for maintaining the position of the rod relative to the cartridge body, particularly in the central position of the cartridge.

Having now fully described this invention, it will be appreciated by those skilled in the art that the invention can be performed within a wide range of parameters within what is claimed, without departing from the scope of the invention, as defined by the claims.

Claims

1 . An aerosol spray can or pressure can (10), specifically of the two-component type, with unidirectional movement activation device of the internal cartridge (14), comprising a can body (12) in which the cartridge (14) is coaxially inserted and stabilized in a known way, which is coupled with a device for its activation or throttle lever (16) housed in a recessed portion (18) of the upper face or of the lower face of the body (12) from which the cartridge itself protrudes with a shaped appendix (20) forming the tang or shank for the connection to the throttle lever (16), the latter defining in the central part a circular core (22) from which the two opposing branches (24) of the lever develop, the circular core reducing its internal diameter to form a circular mouth (30) starting from a circular crown (28), characterised in that the throttle lever, in the central part consisting of the core (22), is provided with a series of shaped recesses (26), which extend at least partly circumferentially along the internal side surface (26') of the core and are intended to cooperate with complementary protrusions (36), which extend on at least one part of the circumference of a bush (32), engaged in the circular mouth (30) and connected to the shaped appendix (20) of the cartridge (14).

2. The can according to claim 1 characterised in that the protrusions (36) of the bush (32) engage in the shaped recesses (26) and, like the latter, define a clockwise orientation which imposes to the throttle lever (16) a right-hand rotation for the activation of the cartridge (14), starting from its shaped appendix (20).

3. The can according to claim 1 or 2 characterised in that the bush (32) consists of a substantially cylindrical body with two different diameters in which the upper part (34) defines the smaller diameter which corresponds to that of the circular mouth (30) of the core (22), while the lower part (37) defines a larger diameter and is peripherally provided with said plurality of protrusions (36), the height of said upper part (34) of the bush (32) being substantially corresponding to that of the internal side surface

(26') of the core (22).

4. The can according to the preceding claim characterised in that the diameter of the external side surface (36') without the protrusions (36) of the lower part of the bush (32) is substantially equivalent to that of the internal side surface (26') of the core (22).

5. The can according to any one of the preceding claims characterised in that the bush (32) is provided with an axial through-hole (38), sized to house and stabilize the shaped appendix (20) coming out of the cartridge (14).

6. The can according to any one of the preceding claims characterised in that the shaped recesses (26) define a substantially triangular shape and are equidistant from each other.

7. The can according to any one of the preceding claims characterised in that the shaped recesses (26) are made along the entire development of the internal side surface (26') of the core (22).

8. The can (10) according to any one of the preceding claims wherein the internal cartridge (14) comprises a longitudinal body (46) which is on one end closed off with a detachable lid or cover (40) and on the other end is connected to the upper face or the lower or back face of the can (10), the cartridge (14) further comprising a rod (42) positioned inside the longitudinal body (46) and extending through the entire length of the cartridge (14), the rod (42) comprising an upper end arranged for being in loose engagement with an inner surface of the cover (40) and a bottom end projecting beyond the upper face or the lower or back face of the can body (12), forming the shaped appendix (20) which is arranged for coupling with the activation device (16).

9. The can according to claim 8 wherein a first elastic ring (58) is provided between the cartridge cover (40) and the cartridge body (46), which elastic ring is adapted for providing a seal between the content of the cartridge (14) and the content of the can (10) outside the internal cartridge (14).

10. The can according to claim 8 or 9 wherein the rod (42) extends through the entire length of the cartridge (14) axially and concentrically relative to the cartridge body (46).

1 1 . The can according to any one of claims 8-10 wherein the rod (42) is provided with lateral extensions (44) adapted for maintaining the position of the rod relative to a cross section of the cartridge (14) which cross section is taken perpendicular to the central axis of the cartridge body (46).

12. The can according to any one of claims 8-1 1 wherein the upper end of the rod (42) comprises an outer screw thread

(48) engaging with a corresponding inner screw thread (50) in the cover (40) of the cartridge (14).

13. The can according to any one of claims 8-12 wherein the cartridge body (46) and the cartridge cover (40) are provided with cooperating means preventing the cover (40) from rotating relative to the cartridge body (46).

14. The can according to claim 12 or 13 wherein the cartridge cover (40) comprises a tube-shaped extension (52) extending axially from the cover outer surface beyond its inner screw thread (50), the tube-shaped extension being open at both ends and arranged for cooperating with the upper end of the rod (42).

15. The can according to claim 14 wherein a recess (54) is provided in at least one axial extension (52) of the cartridge cover (40) and of the rod (42), and a second elastic ring (56) is provided in the recess (54) and adapted for providing a seal between the content of the cartridge (14) and the content of the can (10) outside the internal cartridge (14).

16. The can according to claim 15 wherein the recess (54) is circular.

17. The can according to claim 15 or 16 wherein the second elastic ring (56) is made of rubber.

18. The can according to any one of claims 15-17 wherein the second elastic ring (56) is an o-ring.

19. A process for the production of the can (10) according to any one of the preceding claims, comprising the steps of

• folding a rectangular metal sheet into a cylinder and welding two sides of the metal sheet to form the cylindrical part of the can body (12), • flanging a concave face to one end of the cylindrical part, thereby forming the recessed portion (18), the face comprising a central opening for receiving a cartridge (14),

• coaxially inserting the cartridge (14) into the opening of the face, · stabilizing the inserted cartridge to the can body (12), preferably by shrinking a cup which is comprised as part of the cartridge (14) onto the rims of the opening in the face, thereby forming a flange between the internal cartridge (14) and the face of the can body (12), and

20. The process according to the preceding claim further comprising the step, prior to coaxially inserting the cartridge into the opening of the face, of filling the cartridge (14) with a second component and closing the cartridge with a cover (40).

21 . The process according to claim 19 or 20 further comprising the step of filling the can with a first component and closing the can with a valve, preferably by shrinking a cup which is comprised as part of the valve onto the rim of the opening in the head.

22. The process according to any one of claims 1 9-21 further comprising the step of injecting at least one propellant into the can, preferably injecting the propellant through the valve.

23. The process according to any one of claims 19-22 further comprising the step of connecting the bush (32) to the shaped appendix (20) of the cartridge (14).

24. The process according to the preceding claim further comprising the step of connecting the circular core (22) of the activation device (16) to the bush (32).