Patent Publication Number: US-2023142585-A1

Title: Dispensing head for a trigger dispenser

Description:
FIELD OF THE INVENTION 
     The present invention relates to a dispensing head for a trigger dispenser. In particular, the present invention relates to a dispensing head provided with precompression valve means. 
     BACKGROUND OF THE INVENTION 
     Trigger dispensers are widespread on the market and used to spray liquid products for the most diverse uses: products for the hygiene of the home, for the perfuming of the rooms, for the ironing of fabrics, for gardening, and the like. 
     Every year some hundreds of millions of pieces are produced. It is therefore a sector in which a small improvement, such as to make production more cost-effective, is able to bring a considerable advantage. 
     The present invention, in particular, is directed to a dispensing head provided with precompression means which allow the dispensing of the product present in a precompression chamber only when a predefined threshold pressure is exceeded in said chamber. 
     This feature is extremely appreciated by the market, as the product is dispensed more efficiently, for example by allowing finer nebulization. 
     However, the known solutions of trigger dispensers with precompression means are often complex and therefore expensive. 
     OBJECT OF THE INVENTION 
     The object of the present invention is to provide a trigger dispenser with precompression means which meets the requirements of the field and at the same time overcomes the drawbacks mentioned above with reference to the prior art. 
     Such an object is achieved by a dispensing head according to claim  1 . The dependent claims describe further advantageous embodiment variants. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and the advantages of the dispensing head according to the present invention will appear more clearly from the following description, made by way of an indicative and non-limiting example with reference to the accompanying figures, in which: 
         FIG.  1    shows a sectional view of a dispensing head according to an embodiment of the invention, in a rest configuration; 
         FIG.  2    shows an enlargement of an upper zone of a frame of the dispensing head of  FIG.  1   ; 
         FIG.  3    shows the dispensing head of  FIG.  1   , in a suction configuration; 
         FIG.  4    shows the dispensing head of  FIG.  1   , in a dispensing configuration; 
         FIGS.  5   a  and  5   b    show a frame of the dispensing head of  FIG.  1   ;  FIG.  5   c    is an enlargement of a region of  FIG.  5     a;    
         FIGS.  6   a  and  6   b    show valve means of the dispensing head of  FIG.  1   ; 
         FIG.  7    shows a cover of the dispensing head of  FIG.  1   ; 
         FIG.  8    shows a sectional view of a dispensing head according to a further embodiment of the invention, in a rest configuration; 
         FIG.  9    shows an enlargement of an upper zone of a frame of the dispensing head of  FIG.  8   ; 
         FIG.  10    shows the dispensing head of  FIG.  8   , in a suction configuration; 
         FIG.  11    shows the dispensing head of  FIG.  8   , in a dispensing configuration; 
         FIGS.  12   a  and  12   b    show a frame of the dispensing head of  FIG.  8   ; 
         FIGS.  13   a  and  13   b    show valve means of the dispensing head of  FIG.  8   ; 
         FIG.  14    shows a cover of the dispensing head of  FIG.  8   ; 
         FIG.  15    shows a sectional view of a dispensing head according to yet a further embodiment of the invention, in a rest configuration; 
         FIG.  16    shows an enlargement of an upper zone of a frame of the dispensing head of  FIG.  15   ; 
         FIG.  17    shows the dispensing head of  FIG.  15   , in a suction configuration; 
         FIG.  18    shows the dispensing head of  FIG.  15   , in a dispensing configuration; 
         FIGS.  19   a  and  19   b    show a frame of the dispensing head of  FIG.  15   ; 
         FIGS.  20   a  and  20   b    show valve means of the dispensing head of  FIG.  15   ; 
         FIG.  21    shows a cover of the dispensing head of  FIG.  15   . 
     
    
    
     FIRST EMBODIMENT OF THE INVENTION 
     With reference to a first embodiment of the invention ( FIGS.  1  to  7   ), a trigger dispenser  1  comprises a bottle  2 , provided with a neck  4  having a central axis X, and a dispensing head  6 , applicable to the neck  4 , for example via a threaded connection or a bayonet fitting. 
     The dispensing head  6  comprises a frame  10 , preferably made in a single piece, of plastic material, for example polypropylene, obtained by injection molding. 
     The frame  10  comprises a lower region  12  intended for mechanical coupling with the neck  4  of the bottle  2 , having a lower reference plane  14  which, when the dispensing head  6  is applied to the bottle  2 , is substantially perpendicular to the central axis X of the neck  4 . 
     The lower surface  14  has a venting outlet port  16 , which can be connected with the environment outside the device  1  for the entry of air into the bottle  2 , and a suction inlet port  18  for suctioning the product from the bottle  2 . 
     The frame  10  also internally has a suction duct  20  extending along a suction axis Y, incident to the lower plane  14 , for example orthogonal thereto. 
     A functional zone or upper zone  22  of the frame  10 , intended for the connection of the frame  10  with a cover  24  which will be discussed later, has a suction outlet port  23  and the suction duct  20  extends from the suction inlet port  18  to the suction outlet port.  23 . 
     Preferably, the upper zone  22  provides a reference first plane or upper plane  26  on which the suction duct  20  opens, through a suction shank  28 . 
     The upper zone  22  also has a frame port  30 , for example made on the upper plane  26 . 
     According to a preferred embodiment, the frame  10  has a pressure chamber  32 , inside which a piston  34  can be sealedly slidable along a piston axis Z. 
     The lower zone  12  and the upper zone  22  are on opposite sides of the piston axis Z. 
     The dispensing head  6  further comprises a trigger  35 , preferably hinged to the frame  10 , operable by a user, operatively connected to the piston  34 , so as to operate it in translation in the pressure chamber  32  for dispensing the product, between a limit dispensing position and a rest position. 
     The dispensing head  6  also comprises elastic return means (not shown), adapted to operate permanently on the trigger  35  to bring it towards the rest position. 
     Preferably, the elastic return means are integrated in the trigger structure, i.e. formed in a single piece therewith, for example according to what is illustrated in International Application WO-A1-2017/115159 in the name of the Applicant, whose specific teaching is herein explicitly incorporated. 
     A main duct  36 , preferably extending along a main duct axis K, parallel to and spaced from the suction axis Y, puts the frame port  30  in communication with a chamber port  38  which opens into the pressure chamber  32 . 
     The frame  10  further comprises a dispensing duct  40 , extending along a dispensing axis W, terminating at the front with a dispensing output port  42 . 
     In other words, preferably, the main duct  36  extends along the main duct axis K, the suction duct  20  extends along the suction axis Y and the main duct axis K is parallel to and spaced from the suction axis Y. Moreover, the dispensing duct  40  extends along the dispensing axis W, orthogonal to the suction axis Y and to the main duct axis K. 
     The dispensing head  6  further comprises a nozzle  44 , applicable to the frame  10  at the dispensing outlet port  42  of the dispensing duct  40 , to close it or to diffuse the product in the external environment according to predetermined patterns. 
     The upper zone  22  of the frame  10  also has a dispensing inlet port  46  in communication with the dispensing duct  40 ; preferably, said dispensing inlet port opens at the top of a dispensing shank  48 , protruding from the upper plane  26 . 
     The upper zone  22  of the frame  10  further comprises a frame wall  49  protruding from the upper plane  26 , which surrounds the suction shank  28  and the dispensing shank  48 . 
     Preferably, moreover, the dispensing shank  48  is surrounded by a chamber wall or constraining wall  51 , protruding from the upper plane  26 , provided with openings  53  along the free end edge. 
     The dispensing head  6  further comprises valve means  50 , preferably one-piece, applicable to the frame  10  and suitable for regulating the suction and dispensing of the product. Said valve means  50  are engaged with the upper zone  22  of the frame  10 , and in particular with the frame wall  49 . 
     Preferably, the valve means  50  are made in a single piece, for example in POP (POlyolefin Plastomer), by injection molding. 
     Said valve means  50  comprise a valve body  52 , preferably elongated along a longitudinal axis J, for example of rectangular shape. 
     The valve body  52  comprises a bottom  54 , having an inner face  56 , which when the valve body  52  is applied to the frame  10  faces the upper plane  26 , and an opposite outer face  58 . 
     Once the body  52  has been applied to the upper zone  22  of the frame  10 , the constraining wall  51 , the bottom  54  and the upper plane  26  delimit a precompression chamber  59 , upstream of the dispensing inlet port  46  and downstream of the suction outlet port  23 . 
     The valve means  50  also comprise a suction shutter  60  and a dispensing shutter  62 , preferably made in a single piece with the valve body  52 , protruding from the inner face  56  of the bottom  54 . 
     Preferably, the suction shutter  60  consists of a truncated-cone annular wall  64 , adapted to be inserted on the suction shank  28  of the upper zone  22 , which is sufficiently flexible to deform due to the suction of the product. 
     In particular, the suction shank  28  is inserted inside the annular wall  64 , which, at rest, adheres to the outer surface of said suction shank  28 . 
     During the suction step ( FIG.  3   ), the annular wall  64  is detached from the outer surface of the suction shank  28 , allowing the product coming from the suction duct  20  to pass towards the pressure chamber  32 , through the frame port  30  and the main duct  36 ; during the dispensing step ( FIG.  4   ), the annular wall  64 , by the action of the product pressure, continues to adhere to the outer surface of the suction shank  28 , preventing the product from returning into the bottle through the suction duct  20 . 
     The dispensing shutter  62 , preferably, consists of a portion  66  of the bottom  56 , adapted to close, at rest, the dispensing inlet  46  of the dispensing shank  48 , adhering to the edge thereof. 
     During the dispensing step ( FIG.  4   ), when the pressure of the product in the precompression chamber  59  exceeds a predefined threshold value, the portion  66  rises and becomes detached from the edge of the dispensing inlet port  46 , allowing the product to pass towards the dispensing duct  40 ; during the suction step ( FIG.  3   ), the portion  66  instead remains adherent to the edge of the dispensing inlet port  46 , which thus remains closed, preventing air from the external environment from being suctioned through the dispensing duct  40 . 
     The valve body  52  further comprises:
         an inner perimeter wall  70 , protruding from the bottom  54  on the side of the inner face  56 , which surrounds the suction shutter  60  and the dispensing shutter  62 ;   an outer perimeter wall  72 , which surrounds the inner perimeter wall  70 , at a predefined distance, so as to form a perimeter pocket  74 .       

     At the end of the outer perimeter wall  72 , there is a perimeter shelf  76  protruding externally, orthogonally to the outer perimeter wall  72 ; when the valve body  52  is applied to the frame wall  49 , the perimeter shelf  76  rests on said frame wall  49 , while the outer perimeter wall  72  of the valve body  52  abuts on the frame wall  49 . 
     The dispensing head  6  also comprises a cover  80  suitable for being applied to the frame  10  to cover the upper zone  22 , up to the nozzle  44 . 
     The cover  80  comprises a cap  82  and sides  84 ,  86 ; the cap  82  has an exposed outer surface and an inner surface  88 . 
     The cover  80  comprises an annular inner cap wall  90  and an annular outer cap wall  92 , protruding from the inner surface  88 , between which the outer perimeter wall  72  of the valve body  52  and the frame wall  49  are forcedly forced. The inner cap wall  90  and the outer cap wall  92  thus form an example of connecting means for connecting the valve means to the upper zone  22  of the frame  10 . 
     Moreover, the cover  80  comprises an annular counter-wall  94 , for example continuous or continuous in sections, protruding from the inner surface  88 , configured so as to overlap the constraining wall  51  of the upper zone  22  of the frame. 
     When the valve body  50  is applied to the upper zone  22  of the frame  10 , the bottom  54 , and in particular the portion  66  which implements the dispensing shutter  62 , is against the free edge of the dispensing shank  48 ; when the cover  80  is applied, the inner cap wall  90  and the outer cap wall  92  clamp the outer perimeter wall  72  of the valve body  52  and the frame wall  49 , while the counter-wall  94  is positioned above the constraining wall  51 , pressing the bottom  54  against this. 
     Advantageously, this configuration allows creating an almost interlocking constraint around the portion  66  which constitutes the dispensing shutter  61 , so that this portion  66  operates effectively for the precompression. The product passes through said constraining wall  51  due to the openings  53 . 
     The bottom  54  of the valve body  52 , the counter-wall  94  which is tightly coupled with the bottom  54  and an auxiliary portion  81  of the cap  82  of the cover  80 , define an auxiliary compartment  83 . 
     The cover  80  is also provided with a venting hole  95 , made through the thickness of said auxiliary portion  81  of the cover  80 ; said venting hole  95  allows the escape of the air from the auxiliary compartment  83  during the dispensing step, i.e. during the lifting of the portion  66  of the bottom  54  which closes the dispensing inlet port  46 . 
     Said venting hole  95  therefore provides an example of venting means integrated in the cover  80 , suitable for the escape of air from the auxiliary compartment  83  during the product dispensing step. 
     Preferably, moreover, the cover  80  comprises a shutter abutment  87  protruding from the inner surface  88  and suitable for implementing a travel end abutment for the portion  66  of the bottom  54  during the dispensing step. 
     Said shutter abutment  87  provides an example of abutment means integrated in the cover  80 , suitable for providing a travel end abutment for the dispensing shutter during the dispensing step. 
     SECOND EMBODIMENT OF THE INVENTION 
     According to a further embodiment of the invention ( FIGS.  8  to  14   ), a trigger dispenser  1 ′ comprises a dispensing head  6 ′ and has structural and functional features similar to those illustrated for the above embodiment, except for what will be said hereinafter, using the same numerical references to identify features identical to those described above. 
     A frame  10 ′ has a functional zone or upper zone  22 ′, intended for connecting the frame  10 ′ with a cover  80 ′, having a reference first plane or upper plane  26 ′. 
     A suction shank  28  and a dispensing shank  46  protrude from the upper plane  26 ′ and carry a suction outlet port  23  and a dispensing inlet port  46 , respectively. 
     In this embodiment, the dispensing shank  48  is not surrounded by the constraining wall  51  described for the above embodiment. 
     The dispensing head  6 ′ comprises valve means  50 ′ comprising a valve body  52 ′ having a base  54 ′ having an outer face  56 ′, which when the valve body  52 ′ is applied to the upper zone  22 ′ of the frame  10 ′, is contact with the upper plane  26 ′, and an opposite inner face  58 ′. 
     The base  54 ′ has a wide base opening  96  through its own thickness, surrounded by an annular opening wall  98 , which protrudes from the inner face  58 ′. 
     The valve body  52 ′ further comprises a suction shutter  60 ′ comprising a cantilever arm  100  (or preferably a pair of arms  100 ) with respect to the opening wall  98  and a shutter body  102  provided with a convex surface  104 , for example hemispherical, suitable for closing the suction inlet port  23 . 
     During the suction step ( FIG.  10   ), the shutter body  102  rises and becomes detached from the edge of the suction inlet port  23  of the suction shank  28 , allowing the product coming from the suction duct  20  to pass towards the pressure chamber  32 , through the frame port  30  and the main duct  36 . 
     The product fills a well  106  formed by the opening wall  98  and the upper surface  26 ′ and the excess product is poured onto the base  54 ′, from the side of the inner face  58 ′. 
     The valve body  52 ′ further comprises an annular chamber wall  108  protruding from the inner face  58 ′ of the base  54 ′, configured in such a way that, applying the valve body  52 ′ to the upper zone  22 , said chamber wall  108  surrounds the dispensing shank  48 . 
     The valve body  52 ′ further comprises a dispensing shutter  62  consisting of a flexible membrane  110 , having an outer face  110   a  and an inner face  110   b,  supported by the chamber wall  108 . At rest, the membrane  110  engages the dispensing shank  48  on the side of the inner face  110   b,  closing the dispensing inlet port  46 . 
     The upper plane  26 ′, the chamber wall  108  and the membrane  110  define a precompression chamber  59 ′. 
     The chamber wall  108  has a plurality of chamber passages  112  through the thickness, such as to put the inner face  58 ′ of the base  54 ′ in communication with the precompression chamber  59 ′. 
     The excess product in the well  106 , flows onto the inner face  58 ′ of the base  54 ′ and penetrates into the precompression chamber  59 ′ through the chamber passages  112 . 
     During the dispensing step ( FIG.  11   ), when the pressure of the product in the precompression chamber  59  exceeds a predefined threshold value, the membrane  110  rises and becomes detached from the edge of the dispensing inlet port  46 , allowing the product to pass towards the dispensing duct  40 ; during the suction step ( FIG.  10   ), the membrane  110  instead remains adherent to the edge of the dispensing inlet port  46 , which thus remains closed, preventing air from the external environment from being suctioned through the dispensing duct  40 . 
     The valve body  52 ′ further comprises an inner perimeter wall  70 ′, protruding from the base  54 ′ from the side of the inner face  58 ′, which surrounds the opening wall  98  and the chamber wall  108 ; at the end of the inner perimeter wall  72 ′, there is a perimeter shelf  76 ′ protruding externally, orthogonally to the inner perimeter wall  72 ′; when the valve body  52 ′ is applied to the frame wall  49 , the perimeter shelf  76 ′ rests on said frame wall  49 , while the inner perimeter wall  70 ′ abuts on the frame wall  49 . 
     The dispensing head  6 ′ also comprises a cover  80 ′ suitable for being applied to the frame  10 ′ to cover the upper zone  22 , up to the nozzle  44 . 
     The cover  80 ′ comprises an annular counter-wall  94 ′, for example continuous or continuous in sections, protruding from the inner surface  88 , configured so as to overlap the membrane  110 , with or without contact. 
     The valve body  52 ′ further comprises an annular sealing wall  120 , protruding from the chamber wall  108 , configured to provide a seal with the counter-wall  94 ′ of the cover  80 ′, both in the suction step and in the dispensing step. These features cause the upper face  110   a  of the membrane  110  to be sealedly separated from the suction outlet port  23  and from the frame port  30 , in any working condition of the dispensing head, i.e. both during the suction step and during the dispensing step, to prevent the product from accumulating on the concave upper face  110   a.    
     The membrane  110 , the sealing wall  120 , the counter-wall  94 ′ and an auxiliary portion  81 ′ of the cap  82  of the cover  80  define an auxiliary compartment  83 ′ within which the membrane  110  is deformed during the dispensing step. 
     The cover  80  is also provided with a venting hole  95 , made through the thickness of said auxiliary portion  81  of the cover  80 ; said venting hole  95  allows the escape of the air from the auxiliary compartment  83  during the dispensing step, i.e. during the lifting of the membrane  110 . 
     Said venting hole  95  therefore provides an example of venting means integrated in the cover  80 . 
     The cover  80 ′ further comprises a shutter abutment  87 ′ protruding from the inner surface  88 , surrounded by the counter-wall  94 ′, i.e. inside the auxiliary compartment  83 ′. Said shutter abutment  87 ′ acts as a reference for the membrane  110  in deformation during the dispensing step and therefore provides a further example of abutment means integrated in the cover. Third embodiment of the invention 
     According to a still further embodiment of the invention ( FIGS.  15  to  21   ), a trigger dispenser  1 ″ comprises a dispensing head  6 ″. 
     A frame  10 ″ has a functional zone or upper zone  22 ″, intended for connecting the frame  10 ′ with a cover  80 ″, having a reference first plane or upper plane  26 ″. 
     A suction shank  28  and a dispensing shank  46  protrude from the upper plane  26 ″ and carry a suction outlet port  23  and a dispensing inlet port  46 , respectively. 
     The dispensing shank  48  is surrounded by an annular chamber wall or constraining wall  51 ″, continuous or continuous in sections, continuous provided with openings  53 ″ through the thickness, for example such as to extend over the entire height of said constraining wall  51 ″. 
     The dispensing head  6 ″ comprises valve means  50 ″ comprising a valve body  52 ″, provided with a bottom  54 ″, having an inner face  56 ″, which when the valve body  52 ″ is applied to the frame  10 ″ is facing the upper plane  26 ″, and an opposite outer face  58 ″. 
     The valve means  50 ″ also comprise a suction shutter  60 ″ and a dispensing shutter  62 ″, preferably made in a single piece with the valve body  52 ″, protruding from the inner face  56 ″ of the bottom  54 ″. 
     Preferably, the suction shutter  60 ″ consists of a truncated-cone annular wall  64 ″, adapted to be inserted on the suction shank  28  of the upper zone  22 ″, which is sufficiently flexible to deform due to the suction of the product. 
     In particular, the suction shank  28  is inserted inside the annular wall  64 ″, which, at rest, adheres to the outer surface of said suction shank  28 . 
     During the suction step ( FIG.  17   ), the annular wall  64 ″ is detached from the outer surface of the suction shank  28 , allowing the product coming from the suction duct  20  to pass towards the pressure chamber  32 , through the frame port  30  and the main duct  36  ; during the dispensing step ( FIG.  18   ), the annular wall  64 ″, by the action of the product pressure, adheres to the outer surface of the suction shank  28 , preventing the product from returning into the bottle through the suction duct  20 . 
     The dispensing shutter  62  consists of a membrane  110 ″ having an outer face  110   a ″ and an inner face  110   b ″. The membrane  110 ″ at rest, is adapted to close, from the side of the inner face  110   b ″, the dispensing inlet port  46  of the dispensing shank  48 , adhering to the edge thereof. 
     The constraining wall  51 ″, the membrane  110 ″ and the upper plane  26 ″ delimit a precompression chamber  59 ″, upstream of the dispensing inlet port  46  and downstream of the suction outlet port  23 , in communication with the frame port  30  via said openings  53 ″. 
     During the dispensing step ( FIG.  18   ), when the pressure of the product in the precompression chamber  59 ″ exceeds a predefined threshold value, the membrane  110 ″ rises and becomes detached from the edge of the dispensing inlet port  46 , allowing the product to pass towards the dispensing duct  40 ; during the suction step ( FIG.  17   ), the membrane  110 ″ instead remains adherent to the edge of the dispensing inlet port  46 , which thus remains closed, preventing air from the external environment from being suctioned through the dispensing duct  40 . 
     The valve body  52 ″ further comprises:
         an inner perimeter wall  70 , protruding from the bottom  54 ″ on the side of the inner face  56 ″, which surrounds the suction shutter  60  and the dispensing shutter  62 ;   an outer perimeter wall  72 , which surrounds the inner perimeter wall  70 , at a predefined distance, so as to form a perimeter pocket  74 .       

     When the valve body  52 ″ is applied to the upper zone  22 ″, the frame wall  49  is inserted into the perimeter pocket  74 , tightly sealed. 
     The dispensing head  6 ″ also comprises a cover  80 ″ suitable for being applied to the frame  10 ″ to cover the upper zone  22 ″, up to the nozzle  44 . 
     The cover  80 ″ comprises a cap  82  and sides  84 ,  86 ; the cap  82  has an exposed outer surface and an inner surface  88 . 
     Internally, in front of the inner surface  88  and spaced therefrom it, the cap  80 ″ has a counter-wall  94 ″, which extends parallel to the dispensing axis W, preferably supported by the sides  84 ,  86 . 
     When the cap  80 ′&#39; is applied to the frame  10 ″, the counter-wall  94 ″ operates on the valve body  52 ″, pushing it towards the frame wall  49 , thus fixing the valve body  52 ″ to the frame  10 ″. 
     Preferably, moreover, the counter-wall  94 ″ can be hooked to the frame  10 ″. For example, the upper zone  22 ″ of the frame  10 ″ has a hooking portion  136  and the counter-wall  94 ″ has a hooking slot  138  at the front, within which the hooking portion  136  snaps. 
     The membrane  110 ″ and an auxiliary portion  97 ″ of the counter-wall  94 ″ define an auxiliary compartment  83 ″ within which the membrane  110 ″ is deformed during the dispensing step. 
     The valve body  52 ″ has, on the outer face  58 ″, a transverse groove  134 , preferably positioned so as to ideally intercept the projection of the membrane  110 ″ on the outer face  58 ″, so as to be able to discharge the air from the auxiliary compartment  83 ″ towards the environment during the deformation of the membrane  110 ″. 
     The groove  134  implements an example of venting means integrated in the valve body, suitable for discharging the air during the dispensing step. 
     The valve body  52 ′″ further comprises a body abutment  140  protruding from the outer face  110   a ″ of the membrane  110 ″ which implements a travel end abutment against the counter-wall  94 ″ for the membrane  110 ″ during the dispensing step. 
     Said body abutment  140  implements an example of abutment means integrated in the valve body  52 ″. 
     Advantageously, the cover  80 ″ is applicable to the frame  10 ″ by relative sliding parallel to the dispensing axis W, considerably simplifying the assembly operations of the dispensing head. 
     Further Embodiments of the Invention 
     According to a further embodiment variant of the trigger dispenser, the piston is replaced by a deformable cap membrane. 
     According to a further variant, the trigger is engaged with the frame so as to be translatable. 
     According to a still further variant, the valve means comprise two separate valve bodies, each of which carries the respective dispensing shutter and suction shutter. 
     Innovatively, the dispensing head according to the present invention meets the needs of the sector and overcomes the aforementioned drawbacks. 
     Such a dispensing head allows having a precompression of the product before dispensing, while maintaining a simple structure. 
     Advantageously, moreover, the assembly of the dispensing head is particularly fast, thus positively influencing the production times. 
     It is clear that a man skilled in the art may make changes to the dispensing head described above in order to meet incidental needs, all falling within the scope of protection defined in the following claims.