Patent Description:
Trigger dispensing devices are enormously popular today; several hundred million units are manufactured and sold each year.

These devices are used to dispense liquid products for countless uses, for example hygiene of household surfaces, car cleaning, and plant and animal care.

Exemplary embodiments are shown, for example, in the international <CIT> and <CIT> on behalf of the Applicant.

In some sectors, for example in the area of products dedicated to protecting skin and hair from the effects of the sun, also known as "sun care," or in the area of "aircare" products dedicated to the air quality of an environment, dispensing devices are specially designed to deliver doses in reduced quantities. Preferably, the term reduced dose refers to amounts of less than one milliliter, for example equal to <NUM> milliliters. More generally, in areas such as those indicated above, the dose delivered is roughly half the amount typically delivered for other uses, such as compared to devices in the "home care" sector.

The manufacture of dispensing devices suitable for delivering doses in reduced quantities requires the complex miniaturization of the parts thereof. Specifically, in order to achieve such a reduction in the delivered dosage, without varying the stroke of the moving parts, the bore of the head frame must be varied. Such modifications are however severely limited by compliance with molding conditions, thereby complicating the design and production thereof. Examples of structurally complex trigger dispensing heads are, for example, described in <CIT>, <CIT> and <CIT>.

There is therefore a strong need for a dispensing device suitable for dispensing doses in reduced quantities that is both simple and advantageous to manufacture.

The object of this invention is that of providing a trigger dispensing head that meets the aforesaid requirements and overcomes the aforementioned drawbacks.

This object is achieved by a dispensing head according to claim <NUM>. The dependent claims disclose further advantageous embodiments of the invention.

The features and advantages of the dispensing head according to this invention will be apparent from the description below, given by way of non-limiting example in accordance with the figures in the appended drawings, wherein:.

With reference to the figures of the appended drawings, a trigger dispensing device comprising a bottle <NUM> for containing a liquid product to be dispensed and a trigger dispensing head <NUM> applied to a neck 2a of the bottle has been collectively referred to as <NUM>. The neck 2a has a neck axis X. Preferably, the head <NUM> is applicable to the bottle <NUM> by means of a ferrule system comprising a threaded ferrule <NUM> which may be screwed to the neck 2a or, according to a variant embodiment, by means of a bayonet system, preferably equipped with an anti-removal ridge.

The head <NUM> comprises a frame <NUM>, preferably made in one piece of plastics material, for example by injection molding, adapted to support the components of the head <NUM>.

The frame <NUM> comprises an attachment portion <NUM> provided with a main opening 12a having an attachment axis Z; when the head <NUM> is applied to the neck 2a, the main opening 12a is in communication with a compartment inside the neck 2a, and the attachment axis Z is coincident with the neck axis X.

The head <NUM> also comprises a cylinder chamber <NUM>, of cylindrical circular shape, for example having a chamber axis K orthogonal to the attachment axis Z; preferably, the cylinder chamber <NUM> is formed in the frame <NUM>.

The head <NUM> further comprises a suction duct that connects the main opening 12a with the cylinder chamber <NUM>.

Preferably, said suction duct comprises a first suction segment <NUM> which, starting from the main opening 12a, extends along a first suction axis W, parallel to and preferably spaced apart from the attachment axis Z, and a second suction segment <NUM> which flows into the cylinder chamber <NUM> and extends along a second suction axis Y, parallel to the chamber axis K; for example, the second suction axis Y is coincident with the chamber axis K. The second suction segment <NUM> is delimited by a suction mouth 18a.

Preferably, moreover, the first suction segment <NUM> and/or the second suction segment <NUM> are formed in the frame <NUM>.

The head <NUM> further comprises a dispensing duct that puts the cylinder chamber <NUM> in communication with the external environment.

Preferably, the dispensing duct comprises a first dispensing segment <NUM> which, starting from the cylinder chamber <NUM>, extends along a first suction axis J incident, for example orthogonal, to the chamber axis K, and a second dispensing segment <NUM> which opens into the external environment and extends along a second dispensing axis Q parallel to the chamber axis K.

Preferably, moreover, the first dispensing segment <NUM> and/or the second dispensing segment <NUM> are formed in the frame <NUM>.

Preferably, the dispensing head <NUM> further comprises a nozzle assembly <NUM>, applied to the free end of the second dispensing segment <NUM>, and preferably rotatable at least between a dispensing position, in which the second dispensing segment <NUM> is in communication with the external environment, and a closed position, in which fluid communication between the second dispensing segment <NUM> and the external environment is prevented.

Preferably, the first dispensing segment <NUM> is positioned in a rear region of the dispensing head <NUM>, and the nozzle assembly <NUM> is positioned in a front region of the dispensing head <NUM>.

The dispensing head <NUM> comprises a cylinder wall <NUM>, having an inner chamber surface 24b which annularly delimits the cylinder chamber <NUM>. The cylinder chamber <NUM> is axially delimited by a bottom wall <NUM>, for example from which the suction mouth 18a of the second suction segment <NUM> protrudes.

Preferably, the cylinder wall <NUM> and the bottom wall <NUM> are formed in the frame <NUM>.

According to one embodiment, in the cylinder wall <NUM>, a main vent passage <NUM> is formed which puts the main opening 12a in communication with the cylinder chamber <NUM>, for example with the inner chamber surface 24b.

The head <NUM> further comprises a sleeve <NUM> inserted into the cylinder chamber <NUM> along the chamber axis K, having an inner sleeve surface 32a that annularly delimits a pressure chamber 30a in which a piston <NUM> flows sealingly, which will be described hereinafter.

In accordance with an embodiment, the sleeve <NUM>, the cylinder wall <NUM> and the bottom wall <NUM> define a valve compartment <NUM>' in the cylinder chamber.

According to a first embodiment, the sleeve <NUM> is received in a fixed angular position, i.e. constrained to rotate around the chamber axis K, in such a way as to implement the solution referred to in the international application <CIT> on behalf of the Applicant.

In accordance with a second embodiment, the sleeve <NUM> is rotatable within the cylinder chamber <NUM> around the chamber axis K, in such a way as to implement the solution referred to in the <CIT> on behalf of the Applicant.

The sleeve <NUM> has a sleeve axis M and comprises a bottom wall <NUM> transverse to the sleeve axis M, preferably having an annular end wall <NUM> defining a bottom opening <NUM> of the sleeve <NUM>. The suction duct flows into the sleeve <NUM> through the bottom opening <NUM>; in particular, the second suction segment <NUM> opens into the sleeve <NUM>, for example in the compartment delimited by the end wall <NUM>.

The sleeve <NUM> comprises an annular inner sleeve wall <NUM> that extends axially from the bottom wall <NUM> and annularly delimits the pressure chamber 30a. In addition, the sleeve <NUM> comprises an annular outer sleeve wall <NUM> that extends axially from the bottom wall <NUM> positioned externally radially spaced from the inner sleeve wall <NUM> and put in contact with the inner chamber surface 24b.

In particular, the outer sleeve wall <NUM> has an annular outer surface 66a, positioned directly in contact with the inner chamber surface 24b. Preferably, the outer surface 66a has a converging truncated conical shape, for example converging at the rear.

In one embodiment, the inner sleeve wall <NUM> and the outer sleeve wall <NUM>, both having, for example, cylindrical shapes, are concentric and spaced in the radial direction with respect to the sleeve axis M, annularly defining an annular sleeve gap <NUM> therebetween.

In one embodiment, the sleeve <NUM> is open at a free sleeve end <NUM> axially opposite the bottom wall <NUM>, having a head opening <NUM> delimited by a sleeve edge 33a. Preferably, the annular sleeve gap <NUM> is open at said free sleeve end <NUM>.

The sleeve <NUM> also has a closing wall <NUM> positioned transversely to the sleeve axis M between the inner sleeve wall <NUM> and the outer sleeve wall <NUM>, i.e. having an at least partially annular course, in such a way as to divide the annular sleeve gap <NUM>, along the sleeve axis M, into a first sleeve compartment <NUM>, closed by the bottom sleeve wall <NUM>, and an opposite second sleeve compartment <NUM>, towards the free sleeve end <NUM>. In other words, said second sleeve compartment <NUM> is open and axially accessible through the head opening <NUM>.

The sleeve <NUM> has a secondary vent passage <NUM> passing through the inner sleeve wall <NUM> and the outer sleeve wall <NUM>, suitable for putting the main vent passage <NUM> in communication with the external environment. In particular, the secondary vent passage <NUM> is open between the outer surface 66a and the inner chamber surface 24b, i.e. it is suitable for putting the pressure chamber 30a in communication with the cylinder chamber <NUM>.

The sleeve <NUM> is provided with an annular vent wall <NUM> that extends in a radial direction with respect to the sleeve axis M, between the inner sleeve wall <NUM> and the outer sleeve wall <NUM>, internally delimiting the secondary vent passage <NUM> therein. In other words, said annular vent wall <NUM> has an incident vent axis S, for example orthogonal to the sleeve axis M.

Preferably, said annular vent wall <NUM> is positioned at the closing wall <NUM>, for example by subdividing it substantially into two semi-walls symmetrical in relation to the vent axis S.

The sleeve <NUM> is provided with a pair of angularly spaced partition walls <NUM>, <NUM> extending from the closing wall <NUM> to the bottom sleeve wall <NUM> and defining the angular width of the first sleeve compartment <NUM>.

Preferably, each partition wall <NUM>, <NUM> is positioned on a relevant plane passing through the sleeve axis M.

According to one embodiment, the sleeve <NUM> has a bottom window <NUM> axially passing through the bottom sleeve wall <NUM> and positioned in an imaginary plane passing through the sleeve axis M and passing through the secondary vent passage <NUM>, as seen in <FIG>.

Specifically, the bottom window <NUM> faces the valve compartment <NUM>', i.e., it puts the first sleeve compartment <NUM> in communication with said valve compartment <NUM>'.

The bottom window <NUM> opens for a portion of the circular crown <NUM> radially delimited between the inner sleeve wall <NUM> and the outer sleeve wall <NUM> and angularly delimited between the partition walls <NUM>, <NUM>, as seen in <FIG>.

In other words, the first sleeve compartment <NUM> is axially closed by the closing wall <NUM>, is angularly delimited by the pair of partition walls <NUM>, <NUM> and radially between the inner sleeve wall <NUM> and the outer sleeve wall <NUM>; it is also open at the bottom sleeve wall <NUM> by means of the bottom window <NUM>.

In one embodiment, the sleeve <NUM> comprises a labyrinth seal <NUM> which extends over the outer surface 66a, suitable for putting the main vent passage <NUM> in communication with the external environment.

Preferably, the labyrinth seal <NUM> comprises a channel <NUM>', suitable for putting the main vent passage <NUM> in communication with the external environment. For example, the channel <NUM>' has a circumferential or spiral extension. In an embodiment variant, the channel is linear and curvilinear, for example linear in sections.

Furthermore, the sleeve <NUM> preferably comprises a continuous ridge <NUM> which laterally defines the channel <NUM>'. In particular, said continuous ridge <NUM> is positioned in contact with the inner chamber surface 24b, thus creating a seal against product leakage.

In other words, the labyrinth seal <NUM> is shaped to provide a tortuous path suitable for putting the external environment in fluid connection with the main vent passage <NUM>. In fact, the air may be drawn back, for example as a result of a depression, towards an internal compartment of the bottle <NUM> through the channel <NUM>'; however, a small quantity of liquid that comes out of the main vent passage <NUM> may not go entirely through the channel <NUM>' and exit outside the dispensing head <NUM>. In particular, the continuous ridge <NUM> forces the liquid to continue along the channel <NUM>', preventing the leakage, since it forms a channel with the inner chamber surface 24b.

Further features of the sleeve and labyrinth seal are contained in the international application <CIT> on behalf of the Applicant.

The dispensing head <NUM> further comprises a manually operable piston <NUM> for translating between an initial rest position and a final end-of-stroke position.

The piston <NUM> is inserted into the sleeve <NUM> through the head opening <NUM> and slides so as to seal the inner sleeve surface 32a, i.e., within the pressure chamber 30a.

The piston <NUM>, which is preferably hollow and manufactured as a single piece of plastics material, for example by means of injection molding, comprises an annular piston wall <NUM> extending along a piston axis P between a front end <NUM> and a rear end <NUM>.

Preferably, the piston <NUM> comprises a piston bottom <NUM> at the front end <NUM>. At the rear end <NUM>, the piston <NUM> has a piston engaging portion <NUM> provided with, for example, holes <NUM> for engaging the trigger <NUM> of the head <NUM>.

Preferably, the piston <NUM> comprises a circumferential main piston seal <NUM> and a secondary piston seal <NUM>, projecting externally from the piston wall <NUM>. In particular, inside the sleeve <NUM>, the main piston seal <NUM> axially delimits the pressure chamber 30a together with the bottom wall <NUM>.

Preferably, the secondary vent passage <NUM> is open on the inner sleeve surface 32b between the main piston seal <NUM> and the secondary piston seal <NUM>, in the initial rest position of the piston <NUM>.

The head <NUM> further comprises a trigger <NUM>, comprising a lever actuation portion <NUM> suitable for positioning the user's fingers for actuating the head <NUM>, and a trigger engagement portion <NUM> for connecting with the piston <NUM>. For example, the trigger <NUM> is hinged to the piston <NUM>, by means of the engagement of the trigger engagement portion <NUM> with the piston engagement portion <NUM> of the piston <NUM>.

Preferably, the head <NUM> also comprises elastic return means suitable for operating permanently on the piston <NUM>, directly or indirectly, to bring it to an initial position, which will be discussed later. For example, said return means comprise at least one flexible element <NUM>, preferably a pair of flexible elements, made in one piece with the actuation portion <NUM> of the trigger <NUM>.

The head <NUM> further comprises valve means suitable for adjusting the product flow from the suction duct to the pressure chamber 30a and from the pressure chamber 30a to the dispensing duct. Said valve means are accommodated in the valve compartment <NUM>'.

Preferably, said valve means comprise an at least partially flexible valve element <NUM>, made in a single piece, for example by injection molding.

The valve element <NUM> comprises a tubular portion <NUM> comprising an annular valve wall <NUM> extending along a valve axis V, between a rear end <NUM> defining a rear opening <NUM>, and a front end <NUM>.

The valve element <NUM> further comprises a flexible flap <NUM> connected in a cantilevered manner to the front end <NUM> of the valve wall <NUM>, projecting radially internally.

The flap <NUM> has, on the side facing the rear opening <NUM>, a shutter portion <NUM>, for example having a flat or hemispherical or truncated-cone shape.

The valve element <NUM> further comprises an annular membrane <NUM> that extends radially externally from the tubular portion <NUM>. The membrane <NUM> is, for example, concave on the side facing the front end <NUM> of the tubular portion <NUM>.

The valve element <NUM> further comprises a support portion <NUM> composed of an annular support wall <NUM> that connects to and surrounds the membrane <NUM>.

Preferably, the support wall <NUM> has a flared shape toward the front end <NUM> of the tubular portion <NUM> and, on the side facing the rear end <NUM>, a wavy valve base <NUM> that forms a support for the valve element.

The valve element <NUM> is located in the cylinder chamber <NUM>, against the bottom wall <NUM> against which the valve base <NUM> is placed; the support wall <NUM>, on the other hand, is in contact with the cylinder wall <NUM> and creates a seal against product leakage.

The tubular portion <NUM> is threaded onto the suction duct, and in particular onto the second suction segment <NUM>, and the flap <NUM> forms a flexible shutter for said suction duct. The suction mouth 18a of the suction duct and the flexible flap <NUM> form suitable suction valve means for allowing product to pass from the suction duct to the pressure chamber 30a in a suction step and preventing product from passing from the pressure chamber 30a to the suction duct in a dispensing step.

The membrane <NUM> cooperates with the sleeve <NUM>, and in particular closes the bottom opening <NUM> of the pressure chamber 30a and abuts against the end wall <NUM>. The end wall <NUM> and the membrane <NUM> form pre-compression valve means suitable for allowing product to pass from the pressure chamber 30a to the dispensing duct only when the pressure in the pressure chamber 30a exceeds a predetermined threshold value. Said pre-compression valves are also suitable for preventing the product from passing from the dispensing duct to the pressure chamber 30a during a suction step.

The valve element <NUM>, cooperating with the suction mouth 18a of the suction duct and the end wall <NUM> of the sleeve, thus integrates both the suction valve means and the pre-compression valve means into a single component.

In normal operation of the trigger dispensing device, the head <NUM> is applied to the bottle <NUM>, so that the suction duct is in communication with the compartment inside the bottle <NUM> through the main opening 12a.

Preferably, in an initial configuration in which the trigger <NUM> and the piston <NUM> are in a relevant initial rest position (<FIG>), the pre-compression valve means and the valve suction means are in a relevant closed configuration.

Furthermore, preferably, in the initial configuration, the secondary vent passage <NUM> is axially included between the main piston seal <NUM> and the secondary piston seal <NUM> of the piston <NUM>. Furthermore, in the initial configuration, the main vent passage <NUM> is fluidically isolated from the external environment.

By actuating the trigger <NUM>, the axial translation of the piston <NUM> occurs, said piston moving within the sleeve <NUM> and putting pressure on the product contained in the pressure chamber 30a.

As long as the secondary piston seal <NUM> is positioned axially beyond the secondary vent passage <NUM>, the secondary vent passage <NUM> is in fluid communication with the external environment.

Once a predefined threshold pressure in the pressure chamber 30a has been exceeded, the pre-compression valve means switch to an open configuration in which they allow the passage of the product from the pressure chamber 30a to the dispensing duct.

In particular, the membrane <NUM> separates from the end wall <NUM> of the sleeve <NUM> and allows the product to pass into the valve compartment <NUM>' and then to the dispensing duct, allowing it to be dispensed externally through the nozzle <NUM> (dispensing step). Specifically, the product wets both the valve compartment <NUM>' and the first sleeve compartment <NUM>. The suction valve means remain in the closed configuration (<FIG>).

Once the trigger <NUM> and the piston <NUM> have reached the end-of-stroke position (<FIG>) and the dispensing step has finished, the trigger <NUM> is released and the elastic return means operate to return the piston <NUM> and the trigger <NUM> to the initial rest position.

The return of the piston <NUM> towards the initial rest position causes a depression in the pressure chamber 30a, which causes the switching of the suction valve means to an open configuration in which they allow the suction of the product from the suction duct into the pressure chamber 30a (<FIG>). In particular, the flap <NUM> flexes and separates from the suction mouth 18a of the suction duct, allowing the product to pass from the suction duct into the pressure chamber 30a (suction step). Furthermore, in the suction step, the internal compartment of the bottle is in communication with the external environment by means of the secondary vent passage <NUM> and the main vent passage <NUM>.

According to a preferred embodiment, moreover, the head <NUM> comprises a shell <NUM> attached to the frame <NUM> to cover it. Preferably, the shell <NUM> is applied to the frame <NUM> by at least one snap coupling.

Innovatively, the dispensing head described above meets the needs of the sector and overcomes the aforementioned drawbacks, insofar as it makes it possible to dispense reduced doses of product while interchanging a limited number of components of the head, i.e., avoiding a complete redesign of the head.

Advantageously, it is possible to utilize the frame of the trigger dispensing heads according to the prior art, adapting it to the needs of the sector for dispensing devices that are intended to dispense reduced doses.

Advantageously, the sleeve is a unique and integrated component that is easily interchangeable.

Advantageously, the sleeve has a labyrinth seal that engages with the cylinder chamber, minimizing possible losses of unwanted product.

Claim 1:
A trigger dispensing head (<NUM>) applicable to a bottle (<NUM>) of a trigger dispensing device (<NUM>) for dispensing a product, comprising:
- a frame (<NUM>), suitable for supporting the components of the head (<NUM>), comprising a main opening (12a) suitable to be in communication with an internal compartment of the bottle (<NUM>);
- a cylinder chamber (<NUM>) annularly delimited by a cylinder wall (<NUM>), having an inner chamber surface (24b), and by a bottom wall (<NUM>) at the bottom;
- a manually-operable piston (<NUM>) for translating between an initial rest position and a final end-of-stroke position;
- a pressure chamber (30a) in which said piston (<NUM>) operates;
- a suction duct suitable for putting the internal compartment of the bottle (<NUM>) in communication with the pressure chamber (30a);
- a dispensing duct suitable for putting the pressure chamber (30a) in communication with the external environment;
- valve means for adjusting the product flow from the suction duct to the pressure chamber (30a) during a suction step and from the pressure chamber (30a) to the dispensing duct during a dispensing step;
- a sleeve (<NUM>) having a sleeve axis (M), housed in the cylinder chamber (<NUM>), comprising:
i) a bottom sleeve wall (<NUM>) transverse to the sleeve axis (M);
ii) an annular inner sleeve wall (<NUM>) extending from said bottom sleeve wall (<NUM>) and annularly delimiting the pressure chamber (30a);
iii) an annular outer sleeve wall (<NUM>) extending from the bottom sleeve wall (<NUM>), positioned radially externally spaced from the inner sleeve wall (<NUM>) and placed in contact with the inner chamber surface (24b);
wherein the dispensing head is characterized in that the sleeve (<NUM>) also includes an annular vent wall (<NUM>) that extends radially between the inner sleeve wall (<NUM>) and the outer sleeve wall (<NUM>), internally delimiting a secondary vent passage (<NUM>) passing radially in the inner sleeve wall (<NUM>) and in the outer sleeve wall (<NUM>).