Patent Description:
Such cartridges are typically single-use. They comprise a metal casing inside which the pressurized combustible fluid is present. These cartridges have a bottom, a lateral wall and an upper wall. A perforable zone is present at the centre of the upper wall. A dispenser which is equipped with a needle that pierces the cartridge allowing the fluid to flow out can be connected to the cartridge.

Safety systems are known which prevent the unwanted leak of the fluid; for example, if the still not perfectly empty cartridge is disconnected from the dispenser. In this case there is a sheet supporting an annular gasket. The sheet comprises four teeth between which the annular gasket is mounted. Appropriately, this sheet is fixed to two ends in a perimeter groove obtained along the lateral wall of the cartridge. The annular gasket is placed in the middle of this support sheet. In a fluid dynamic seal configuration, the annular gasket exerts a seal along a closed line that surrounds a zone in which the dispenser needle is expected to pierce the cartridge. When the needle pierces the cartridge, the needle will press on the support of the annular gasket moving it away from the upper wall. In this way, the fluid present in the cartridge is allowed to reach the hole made by the needle and therefore dispensing is allowed.

Cartridges are disclosed in <CIT>, <CIT>, <CIT>.

In this context, the technical task underlying the present invention is to propose a cartridge which allows the components to be optimized, allowing at the same time both high operational safety and competitive costs.

The stated technical task and specified objects are substantially achieved by a cartridge comprising the technical features set forth in one or more of the appended claims.

Further features and advantages of the present invention will become more apparent from the illustrative and thus non-limiting description of a preferred but not exclusive embodiment of a cartridge as illustrated in the appended drawings, in which:.

In the accompanying figures, the reference number <NUM> indicates a pressurized fluid cartridge (it is typically a gas; it could possibly also be in the liquid state inside the cartridge due to compression; when it is dispensed by the cartridge it is typically in gaseous form). This pressurized fluid is typically a fuel, for example it comprises butane and/or propane.

The cartridge <NUM> comprises an outer casing <NUM> which defines a tank for the fluid. Appropriately, the cartridge <NUM> or rather the casing <NUM> comprises a bottom <NUM>, a lateral wall <NUM> and an upper wall <NUM> opposite the bottom <NUM>. Appropriately, the cartridge <NUM> comprises a safety means <NUM> that opposes (in particular limits/prevents the) the leak of the fluid from the cartridge <NUM> after perforation of a predetermined perforable part <NUM> afforded in the upper wall <NUM>.

Therefore, it limits/prevents the leak of the fluid from the cartridge through a hole made by a dispenser for drawing the fluid. For example, the means <NUM> limits/prevents the leak of fluid from a cartridge which, by mistake or for any other reason, is decoupled from the dispenser (even if it is not completely exhausted). During coupling with the dispenser there are no unwanted leaks of fluid from the cartridge <NUM> as the dispenser is equipped with a seal element. The safety means <NUM> in a dispensing configuration allows the fluid to flow out from the cartridge. In fact, in this configuration it is the dispenser which, by means of a needle for piercing the cartridge, interacts with the safety means <NUM> allowing the fluid to flow out. The safety means <NUM>, however, tends to spontaneously evolve towards a safety configuration in which it prevents/limits the leak of the fluid from the cartridge (appropriately when the dispenser is removed). The safety means <NUM> allows/prevents/limits the leak of the fluid from a hole made by the needle (in particular it allows the fluid to flow out when there is a correct coupling with the dispenser, while on the other hand it prevents/limits the leak of the fluid when the dispenser is decoupled).

The safety means <NUM> comprises a fluid dynamic seal means <NUM> which in a fluid dynamic seal configuration contacts the upper wall <NUM> along an imaginary closed line which surrounds said predetermined perforable part <NUM>.

The lateral wall <NUM> connects the bottom <NUM> and the upper wall <NUM>. The lateral wall <NUM> can be substantially cylindrical, for example, possibly with a tapering towards the upper wall <NUM>. The bottom <NUM> and/or the lateral wall <NUM> and/or the upper wall <NUM> are appropriately metallic. Appropriately, the walls of the cartridge <NUM> have a thickness of less than <NUM> millimetre, preferably less than or equal to <NUM> millimetres.

The upper wall <NUM> is for example shaped like a dome. In a central zone of the upper wall <NUM> (or dome), the upper wall <NUM> (or dome) can advantageously define a recess which protrudes towards the inside of the cartridge <NUM> (i.e. towards the bottom <NUM>). This central zone of the upper wall <NUM> is located on a top of the dome.

Appropriately the perforable part <NUM> (or better, the part intended for perforation typically using a dispenser) is part of said recess. The perforable part <NUM> is located in a central zone of the upper wall <NUM>.

The cartridge <NUM> is intended to be perforated in said part <NUM> by an outer dispenser.

In this way the means <NUM> separates a compartment <NUM> containing the fluid from a zone <NUM> interposed between said seal means <NUM> and said perforable part <NUM>. The fluid dynamic seal configuration coincides with the safety configuration illustrated above. In the dispensing configuration, the fluid dynamic seal means <NUM> is moved away from the upper wall <NUM>. In this dispensing configuration, between the upper wall <NUM> and the fluid dynamic seal means <NUM> there is therefore a passage for the outflow of the fluid. If the cartridge <NUM> were perforated externally to this perforable part <NUM>, the safety means <NUM> would not perform a safety action (but the connection between dispenser and cartridge <NUM> is such as to cause the perforation in this perforable part <NUM>).

The safety means <NUM> comprises a flexible strip <NUM> which pushes the seal means <NUM> towards the upper wall <NUM>. The strip <NUM> is therefore a spring. Preferably the strip <NUM> is symmetrical. In particular the strip <NUM> is symmetrical with respect to a plane. Appropriately the strip is symmetrical with respect to a plane that is orthogonal to an outer support plane on which the bottom <NUM> rests. The strip <NUM> does not come into contact with the bottom <NUM> either in the fluid dynamic seal configuration or in the fluid dispensing configuration.

The strip <NUM> defines a housing cup <NUM> in which the fluid dynamic seal means <NUM> is at least partially housed. For example, the cup <NUM> has a depth comprised between <NUM> and <NUM> millimetres. Appropriately the positioning of the fluid dynamic seal means <NUM> in the cup <NUM> facilitates the assembly thereof both in terms of speed and in terms of production flexibility (the assembly can be carried out during the implementation of the strip <NUM> or later).

The seal means <NUM> suitably comprises/is a gasket. The seal means <NUM> is housed in the cup <NUM>, preferably not projecting out of the cup <NUM>. The seal means <NUM> may be flush with an upper edge of the cup <NUM>. The cup <NUM> defines an annular housing seat <NUM> on which the gasket rests. Appropriately the cup <NUM> comprises a closed bottom <NUM>. It is intended to abut the dispenser needle which pierces the upper wall <NUM>. Appropriately, the needle pierces the upper wall <NUM>, passes through the gasket and contacts the bottom <NUM> of the cup <NUM>, pushing it away from the upper wall <NUM>. In this way the safety means <NUM> passes from the safety configuration to the dispensing configuration. It should be noted that the needle can pass through the gasket without damaging it since the gasket is advantageously annular. The housing seat <NUM> on which the gasket rests circumscribes a central recess <NUM> intended to abut the dispenser needle which allows the cartridge <NUM> to be pierced. However, this recess <NUM> could also be absent. The bottom <NUM> of the cup <NUM> could for example be flat or have a convexity which protrudes towards the upper wall <NUM> (solutions not shown). In both cases the bottom <NUM> is intended to abut the dispenser needle.

The seal means <NUM> comprises/is a ring having a constant cross section. It could possibly have a circular or polygonal cross section. In particular, this cross section is constant along the entire extension of the ring. For example, the seal means <NUM> comprises/is an O-ring (or an X-ring or a square or rectangular cross-sectional ring).

Appropriately, the seal means <NUM> is made of a compressible material, e.g. rubber or elastomer.

The strip <NUM> comprises at least a first and a second arm <NUM>, <NUM>. The strip <NUM> comprises an intermediate zone <NUM> to the first and the second arm <NUM>, <NUM> in which said cup <NUM> is afforded. From the intermediate zone <NUM> the first and second arm <NUM>, <NUM> extend towards the casing <NUM>, in particular towards the lateral wall <NUM>. The first and the second arm <NUM>, <NUM> both extend starting from the intermediate zone <NUM>. Appropriately, the first and the second arm extend away from the intermediate zone <NUM> until coming into contact with the casing <NUM>, in particular with the lateral wall <NUM>.

The first and the second arm <NUM>, <NUM> are symmetrical and extend according to opposite directions starting from the intermediate zone <NUM>.

The cup <NUM> is made of the same material and is in a single body with the first and the second arm <NUM>, <NUM>. The first and the second arm <NUM>, <NUM> and the cup <NUM> are thus a single monolith. Appropriately, the strip <NUM> is made of metallic material.

The strip <NUM> is preferably made of tinplate. Such material has optimal ductility. Appropriately, the strip <NUM> is made of the same material as the bottom <NUM>, the lateral wall <NUM> and the upper wall <NUM>. This minimizes the risk of corrosion. In an alternative, not preferred solution, the strip <NUM> could be made of plastic material.

Typically the strip <NUM> is a single body to which the fluid dynamic seal means <NUM> is assembled. Advantageously, the fluid-dynamic seal means <NUM> are assembled with the strip <NUM> and not in a single piece with the strip <NUM>. Conveniently, the fluid-dynamic seal means <NUM> are assembled with the cup <NUM> and not in a single piece body with the cup <NUM>.

The seal means <NUM>, for example, may be connected by interference or by friction to the cup <NUM>. The cup <NUM> can have straight side flanks or defining an undercut (e.g. for holding the seal means <NUM> better).

Appropriately, the strip <NUM> is elastic and pushes the seal means <NUM> against the upper wall <NUM>. The strip <NUM> pushes the seal means <NUM> so that the safety means <NUM> spontaneously evolves from the dispensing configuration to the safety configuration. Appropriately the strip <NUM>, on the other hand, opposes the passage from the safety configuration to the dispensing configuration. This passage is instead forced by the pressure exerted by the dispenser needle after having penetrated through the perforable part <NUM>. In the dispensing configuration it is therefore the dispenser needle that keeps the seal means <NUM> away from the upper wall <NUM> (allowing the fluid to flow out).

Appropriately the strip <NUM> is constrained to the casing <NUM> (in particular to the lateral wall <NUM>) at a first and a second end <NUM>, <NUM>. For example, the strip <NUM> is mechanically constrained to the casing <NUM>. As exemplified in <FIG> the first and the second end <NUM>, <NUM> are associated with one or more grooves afforded on the lateral wall <NUM> of the cartridge <NUM>. In an alternative not preferred solution, which is not illustrated, the strip <NUM> could be connected to the casing <NUM> by welding or adhesive means.

The first arm <NUM> extends between said intermediate zone <NUM> and the first end <NUM>.

The intermediate zone <NUM> appropriately comprises a platform <NUM> from which the cup <NUM> extends. The cup defines a concavity facing the upper wall <NUM>. Appropriately, along the perimeter of the platform <NUM> one or more recesses <NUM> are afforded. Appropriately, the platform <NUM> is horizontal. The cup <NUM> extends fully below the platform <NUM> or however more below the platform <NUM> than above it. The platform <NUM> separates the first and the second arm <NUM>, <NUM>. In particular, the platform <NUM> is in contact on opposite sides both with the first and the second arm <NUM>, <NUM>.

The cartridge <NUM> according to the present invention will be described below, with particular reference to the solution of <FIG>.

The first arm <NUM> comprises a first slope <NUM> that extends from said intermediate zone <NUM>, in particular it extends from the platform <NUM>. In a particular non-limiting solution the first slope <NUM> extends in length for a dimension comprised between <NUM> and <NUM> millimetres. Appropriately, the first slope <NUM> extends in width for a dimension comprised between <NUM> and <NUM> millimetres, preferably between <NUM> and <NUM> millimetres. Appropriately, the thickness of the first slope <NUM> is less than <NUM> millimetres (advantageously this can be repeated for the entire strip <NUM>).

Appropriately, the strip <NUM> comprises a width (evaluated orthogonally with respect to a predominant extension line) less than <NUM> millimetres. The use of a commercial O-ring also facilitates the containment of the width of the strip <NUM>.

The first slope <NUM> and the intermediate zone <NUM> appropriately have a bending zone in common. It typically defines a bending edge.

The strip <NUM> comprises a first concavity <NUM> appropriately turned downwards. An edge of said first concavity <NUM> also defines the first end <NUM>. The first concavity <NUM> is appropriately defined by two converging portions. One of such portions has a length comprised between <NUM> and <NUM> millimetres and the other has a length comprised between <NUM> and <NUM> millimetres. By way of example, such two converging portions define an interposed angle of width comprised between <NUM>° and <NUM>° in the fluid dynamic seal configuration.

The strip <NUM> comprises a first portion <NUM> interposed between the first slope <NUM> and the first concavity <NUM>. The first portion <NUM> joins the first slope <NUM> and the first concavity <NUM> (therefore it is adjacent to both). The joining zone of the first portion <NUM> with the first concavity <NUM> is a bending zone of the strip <NUM>. The first portion <NUM> is appropriately substantially rectilinear (at least in the fluid dynamic seal configuration). Despite this, at least in the fluid dynamic seal configuration (or more generally when it is inside the cartridge <NUM>), the first portion <NUM> is not horizontal. Such first portion <NUM> has a length comprised between <NUM> and <NUM> millimetres. Appropriately, the first portion <NUM> has a width comprised between <NUM> and <NUM> millimetres.

Along the linear extension of the first arm <NUM> the ratio between the length of the first slope <NUM> and the length of said first interposed portion <NUM> is comprised between <NUM> and <NUM>.

The fact that the length of the first slope <NUM> is similar to that of the first portion <NUM> enables the strip <NUM> to be processed better without overloading specific zones.

The first portion <NUM> interposed in the seal configuration extends downwards starting from the first concavity <NUM>.

The first arm <NUM> comprises at least a first and a second bend <NUM>, <NUM>.

The first and the second bend <NUM>, <NUM> at least in the fluid dynamic seal configuration are located in two opposite half-spaces with respect to an imaginary plane <NUM> which passes through the first end <NUM> of the first arm <NUM> and orthogonal to an axis defining the extension in height of the cartridge <NUM>. Such axis is orthogonal to an outer support plane on which the bottom <NUM> is placed. When the cartridge <NUM> is normally supported this axis is vertical.

Appropriately, the first arm <NUM> also comprises a third bend <NUM>.

The third bend <NUM> corresponds to the bending zone interposed between the first interposed portion <NUM> and the first slope <NUM>. Appropriately, the third bend <NUM> comprises a connection radius comprised between <NUM> and <NUM>, for example between <NUM> and <NUM> millimetres, preferably comprised between <NUM> and <NUM> millimetres.

The first arm <NUM> also comprises a fourth bend <NUM>. Appropriately, the fourth bend <NUM> corresponds to the bending zone interposed between the intermediate zone <NUM> and the first slope <NUM>.

Appropriately in the solution exemplified in the appended figures the first arm <NUM> along the longitudinal extension comprises exactly four bends. The second arm <NUM> extends between the intermediate zone <NUM> and the second end <NUM>.

Appropriately in the seal configuration the first and fourth bend <NUM>, <NUM> lie in the first of the two half-spaces identified by the imaginary plane <NUM>. In the seal configuration, the second and third bend <NUM>, <NUM> lie in a zone identified by the union of the imaginary plane <NUM> and the second of the two half-spaces identified by the plane <NUM>.

What has been described with reference to the first arm <NUM> may also be repeated for the second arm <NUM>.

In the fluid dynamic seal configuration extensions of the first and the second portion <NUM>, <NUM> are converging (in particular they identify an upward concavity).

In a configuration in which the strip <NUM> is undeformed and extracted from a compartment <NUM> delimited by the combination of the bottom <NUM>, the lateral wall <NUM> and the upper wall <NUM>, the first and the second interposed portion <NUM>, <NUM> are coplanar. This configuration is exemplified in <FIG>. It is to be noted that in the preferred solution, in order to be able to extract the strip <NUM> from the casing <NUM> which defines the compartment <NUM> it is necessary to irreparably destroy the casing <NUM>.

Appropriately, in the undeformed configuration (e.g. <FIG>) the ratio between:.

Appropriately, the angle comprised between said first slope <NUM> and said first intermediate portion <NUM> is comprised between <NUM> and <NUM>° in the fluid dynamic seal configuration.

Appropriately, the first and the second slope <NUM>, <NUM> are rectilinear. Appropriately, extensions of the first and second slope <NUM> towards the upper wall <NUM> are converging.

In the solution exemplified in <FIG> the first arm <NUM>, at the joining zone with the platform <NUM>, comprises two U-bent portions <NUM>, <NUM>. They define a concavity turned the upper wall <NUM>. Appropriately such two portions <NUM>, <NUM> are opposing each other. Appropriately they are close to each other. Appropriately, one of the two portions <NUM>, <NUM> extends less in height than the other. Such portion which extends less in height is the most distant one from the platform <NUM>. A first flap <NUM> (appropriately rectilinear) extends from one of the two U-bent portions <NUM>, <NUM>. Appropriately, the first flap <NUM> extends from the portion that extends less in height.

Likewise, also the second arm <NUM>, at the joining zone with the platform <NUM>, comprises two U-bent portions. A second flap <NUM> (appropriately rectilinear) extends from one of them.

The strip <NUM> comprises a collar <NUM> which projects towards the upper wall <NUM> and surrounds the cup <NUM>. Appropriately it delimits the perimeter of the cup <NUM>.

Subject matter of the present invention is a method for making a cartridge <NUM> having one or more of the characteristics described hereinabove.

The method comprises the step of arranging the flexible strip <NUM> provided with the first and the second arm <NUM>, <NUM> and extending between a first and a second end <NUM>, <NUM>.

As mentioned above, the first arm <NUM> comprises: a first slope <NUM> which extends from said intermediate zone <NUM>, a first concavity <NUM>, a first portion <NUM> interposed between the first slope <NUM> and the first concavity <NUM>.

The second arm <NUM> comprises a second slope <NUM> that extends from said intermediate zone <NUM>, a second concavity <NUM>, a second portion <NUM> interposed between the second slope <NUM> and the second concavity <NUM>. In an undeformed configuration of the strip <NUM> the first and said second intermediate portions <NUM>, <NUM> are coplanar. In particular they define a horizontal pedestal for the strip <NUM>. This facilitates the movement of the strip <NUM>. In the undeformed configuration the ratio between an angle comprised between said intermediate zone <NUM> and the first slope <NUM> and an angle comprised between said first slope <NUM> and said first interposed portion <NUM> is comprised between <NUM> and <NUM>.

Appropriately, the method comprises the step of housing the strip <NUM> in a compartment <NUM> defined by the lateral wall <NUM> and by the upper wall <NUM>. The method also comprises the step of introducing the pressurized fluid into the compartment <NUM>.

The method then comprises the step of occluding the compartment <NUM> by connecting the bottom <NUM> to the lateral wall <NUM>.

The present invention achieves important advantages.

First of all it enables the components of the cartridge to be optimized. This is important in order to reduce production costs.

In particular, the use of a gasket recessed into the strip enables the production costs of the safety system to be minimised. It further facilitates the use of a standard commercial gasket, e.g. an O-ring and does not require the use of an appropriately shaped gasket.

In the preferred solution, a careful study of the geometry of the strip <NUM> allows to implement measures aimed at optimizing an effective action for the purpose of optimizing the safety of the cartridge.

The invention as it is conceived is susceptible to numerous modifications and variants, all falling within the scope of the inventive concept, as defined in the appended claims.

Claim 1:
A pressurized fluid cartridge comprising:
i) a bottom (<NUM>), a lateral wall (<NUM>) and an upper wall (<NUM>) opposite the bottom (<NUM>);
ii) a safety means (<NUM>) that opposes the leak of fluid from the cartridge (<NUM>) after perforation of a predetermined perforable part (<NUM>) afforded in the upper wall (<NUM>);
said safety means (<NUM>) comprising:
*) a fluid dynamic seal means (<NUM>) which in a fluid dynamic seal configuration contacts the upper wall (<NUM>) along an imaginary closed line which surrounds said predetermined perforable part (<NUM>);
*) a flexible strip (<NUM>) which pushes said seal means (<NUM>) towards the upper wall (<NUM>), the strip (<NUM>) being a single body to which the fluid dynamic seal means (<NUM>) is assembled; said strip (<NUM>) comprising:
- a housing cup (<NUM>);
- at least a first and a second arm (<NUM>, <NUM>);
- an intermediate zone (<NUM>) to the first and the second arm (<NUM>, <NUM>) in which said cup (<NUM>) is afforded and from which the first and the second arm (<NUM>, <NUM>) extend towards the lateral wall (<NUM>), said cup (<NUM>) being made of the same material and in a single body with the first and the second arm (<NUM>, <NUM>);
characterised in that the fluid dynamic seal means (<NUM>) is at least partially housed in the housing cup (<NUM>); the housing cup (<NUM>) defining a concavity facing the upper wall (<NUM>).