Abstract:
Trigger dispensers for liquids which include a dispenser head having a sliding valve dispenser element are provided. Also provided are dispenser heads suitable for use with trigger dispensers for liquids.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Phase Application of PCT International Application No. PCT/IB2013/054511, International Filing Date, May 31, 2013 claiming priority to Italian Patent Application No. BS2012A000109, filed Jul. 17, 2012, each of which is hereby incorporated by reference in its entirety. 
     FIELD OF THE INVENTION 
     The object of the present invention is a manual dispenser for a liquid, preferably a trigger dispenser. 
     BACKGROUND OF THE INVENTION 
     Trigger dispensers are highly widespread and used in different fields, for example for spraying household detergent liquids, anti-odour liquids, clothing ironing liquids. The production volumes of such devices are very large; a few hundred million pieces a year are currently produced. 
     It is therefore clear that improving a structural feature of a component of the dispenser or improving a step of the production process have a considerable economic implication. 
     In the specific field, many efforts in the research and development of new components aim to integrate a plurality of functions in a single component, especially if such component can be moulded. 
     In particular, trigger dispensers are known in which a single component integrates multiple valve functions, for example as described in the International Patent Application WO 2012/069939 by the Applicant. 
     However, known devices have some drawbacks, for example related to a poor behaviour repeatability in the dispensing. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a manual liquid dispenser, in particular a trigger dispenser, which should meet the requirements of structural simplicity while overcoming the drawbacks mentioned with reference to the prior art. 
     Such object is achieved by a manual dispenser as described and claimed herein. 
     Features and advantages of trigger dispensers and dispenser heads according to the present invention will be evident from the following description, with reference to the annexed Figures. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a cross section of a dispenser head of a dispenser according to an embodiment of the present invention; 
         FIG. 2 a    shows an enlargement of a detail of  FIG. 1 , wherein a valve dispenser element in a rest configuration is highlighted; 
         FIG. 2 b    shows the valve dispenser element in a pre-dispensing configuration of an active step; 
         FIG. 2 c    shows the valve dispenser element in a dispensing configuration of the active step; 
         FIG. 3 a    shows a main body of the dispenser element of the head of  FIG. 1 ; 
         FIG. 3 b    shows a cross section of the main body of  FIG. 3   a;    
         FIG. 4 a    shows an auxiliary body of a connection element of the head of  FIG. 1 ; 
         FIG. 4 b    shows a cross section of the auxiliary body of  FIG. 4   a;    
         FIG. 5  shows a cross section of a dispenser head of a dispenser according to a further embodiment of the present invention; 
         FIG. 6  shows an enlargement of a detail of  FIG. 5 ; and 
         FIG. 7  shows a frame of the head of  FIG. 1 ; 
         FIG. 8  shows a cross section of a dispenser head of a dispenser according to an even further embodiment of the present invention; 
         FIG. 9  shows an enlargement of a detail of  FIG. 8 ; 
         FIG. 10 a    shows an auxiliary body of the connection element of the head of  FIG. 8 ; 
         FIG. 10 b    shows a cross section of the auxiliary body of  FIG. 10   a;    
         FIG. 10 c    shows a side view of the auxiliary body of  FIG. 10   a;    
         FIG. 11 a    shows a main body of the valve element of the head of  FIG. 8 ; 
         FIG. 11 b    shows a cross section of the main body of  FIG. 11 a   ; and 
         FIG. 11 c    shows a side view of the main body of  FIG. 11   a.    
     
    
    
     DETAILED DESCRIPTION 
     With reference to the annexed figures, a manual dispenser  1  comprises a container C having an inner compartment V for the containment of the liquid to be dispensed, comprising a neck N consisting of an annular wall about a container axis X, which by an annular edge B defines a container opening A to access inside said compartment V. 
     Dispenser  1  comprises a dispenser head  20  attached to container C for manually drawing the liquid from the container and dispense it to the exterior. 
     Head  20  is preassembled and is generally sent to the filling of the container separately therefrom. After filling the container with liquid, the head is coupled to the container. 
     For example, head  20  may be coupled to container C by means of a threaded closure comprising a threaded ring nut  21  ( FIGS. 1 to 7 ) or by means of a bayonet closure ( FIG. 8  and following ones). 
     Head  20  further comprises a frame  22  which may be coupled to container C, preferably made as a single piece, for supporting the other components and making some passages for the liquid. 
     Frame  22  has a pressure chamber  24 , annularly delimited by a chamber wall  25 , having extension along a pressure axis Y, preferably incident with the container axis X, for example orthogonally. 
     Head  20  comprises a piston  26 , sealingly slidable in the pressure chamber  24  along the pressure axis Y, between a rest position in which the volume of the pressure chamber  24  is maximum, and a limit dispensing position, in which the volume of the pressure chamber  24  is minimum, passing by intermediate dispensing positions. 
     Preferably, piston  26  comprises a head seal  26   a  and a tail seal  26   b , spaced apart from the head seal along the pressure axis Y, for the seal between piston and the chamber wall  25  in which it slides. 
     Head  20  further comprises a manual actuation element adapted to manually move piston  26  in the pressure chamber  24 . 
     Preferably, the actuation element comprises a trigger  28 , adapted to operate on piston  26 , for example anchored thereto, and engaged with frame  22 , for example rotatably hinged thereto or sliding in translation thereon. 
     Preferably, moreover, head  20  comprises an elastic return element suitable for influencing piston  26  or trigger  28  for returning piston  26  towards the rest position. 
     Frame  22  further has a dispenser duct  30  having extension along a dispensing axis Z, between a distal end  32 , at the outwards opening, and an opposite distal end  34 . 
     Preferably, the pressure axis X is parallel to and separate from the dispensing axis Z. 
     Preferably, head  20  further comprises a nozzle  38 , attached to the distal end  32  of the dispenser duct  30 , for allowing the liquid to be dispensed according to the desired modes. 
     Frame  22  preferably comprises a mouth  90 , formed by a mouth wall  92 , having axial extension, which communicates with the pressure chamber  24  through a passage  93 . 
     The mouth wall  92  is provided with an inner surface  92   a , comprising a first portion or continuous cylindrical portion  92   a ′, immediately upstream of passage  93 , and a second portion or flared portion  92   a ″, having a truncated-cone shape, converging towards passage  93 , jointed to the cylindrical portion  92   a′.    
     The flared portion  92   a ″ consists of a plurality of projections  92   b  in a circumferential sequence, separated by recessed passages  92   b ′ ( FIG. 7 ). 
     Moreover, frame  22  comprises an annular connection wall  100  about the container axis X, radially externally spaced apart from the mouth wall  92 . 
     Said connection wall  100  annularly delimits an intermediate compartment  102  suitable to be placed in communication with passage  93  through mouth  90  and in communication with an intermediate duct  104 , which connects said intermediate compartment  102  with the dispenser duct  32 , and in particular with the proximal end  34  thereof. 
     Preferably, the intermediate duct  104  extends along an intermediate axis K, parallel to the container axis X. 
     In particular, according to a preferred embodiment, the intermediate duct  104  laps the pressure chamber  24 , from which it is separated by a bottom wall  24   a  which constitutes the bottom of the pressure chamber  24 . 
     According to a further embodiment ( FIG. 8  and following ones), frame  22  comprises a secondary connection wall  112 , annular about the container axis X, radially externally spaced apart from the connection wall  100 . 
     Moreover, frame  22  comprises a venting duct  110  suitable to place in communication compartment V inside container C with the external environment; said venting duct  110  opens towards the exterior on the sliding surface on which the sealing lips  26   a ,  26   b  of piston  26  slide. 
     Head  20  further comprises a valve dispenser element suitable for preventing the dispensing of liquid from the pressure chamber towards the dispenser duct up to reaching a predetermined threshold pressure in the pressure chamber. 
     Said valve dispenser element comprises a main body  200 , made of a flexible material, such as EVA (ethyl-vinyl-acetate), PELD (low density polyethylene) or TPE (thermoplastic elastomer), attached to the connection wall  100  and to the mouth wall  92  of the frame so as to delimit the intermediate compartment  102 . 
     The main body  200  comprises an annular membrane  202 , attached to the connection wall  100 . 
     According to an embodiment, in a rest configuration the membrane has a dome shape, convex towards the intermediate compartment  102  and concave at the opposite side. 
     The main body  200  further comprises an annular sealing lip  204 , axially protruding from membrane  202  in the intermediate compartment  102 , suitable for sealingly resting against the inner surface of the connection wall  100 . 
     Preferably, the sealing lip  204  protrudes from membrane  202  to a predetermined distance from the peripheral edge, so as to determine a residual portion  206  of said membrane  202 , which radially extends outside the sealing lip  204 . 
     Preferably, the residual portion  206  abuts on the free end of the connection wall  100  of frame  22 . 
     Moreover, the main body  200  comprises an annular engagement wall  208 , having axial extension, protruding from membrane  202  towards the intermediate compartment  102 . 
     The engagement wall  208  annularly delimits a feeding compartment  210 , open on one side towards mouth  90  and passage  93  towards the pressure chamber  24  and on the other side through a gap  212  in membrane  202 . 
     Moreover, preferably, the engagement wall  208  has an outer surface  208   a  having at least one end zone, distal from membrane  202 , flared outwards. 
     According to a preferred embodiment ( FIG. 8  and following ones), the main body  200  comprises a plurality of spacing elements  214 , axially projecting from membrane  202 , on a side opposite to the sealing lip  204 , for constituting a firm support for the main body  200  on base  502  of the auxiliary body  500 . Preferably, said spacing elements are arranged as a crown, peripherally to the main body  200 , forming a sequence of ridges and depressions. 
     Moreover, head  20  comprises a check valve element suitable for preventing the return of liquid from the pressure chamber  24  towards the container. 
     According to a preferred embodiment ( FIGS. 1, 2, 3   a ,  3   b ,  8  and following ones), the check valve element comprises a shutter  300 , for example a ball, movable in the feeding duct  210  of the main body  200 , and a shutter seat  302 , for example having a truncated-cone shape, which defines gap  212 . 
     Moreover, said check valve element comprises a retaining element suitable for retaining shutter  300  within the feeding duct  210 . 
     For example, said retaining element comprises at least one protrusion  304 , protruding within the feeding duct  210 . 
     According to a further embodiment ( FIGS. 5 and 6 ), shutter  300  of the check valve element consists of a flexible septum  400  set to close the feeding duct  210 , hinged along a stretch of the edge thereof and separated by a cut. 
     In said embodiment, the engagement wall  208  cooperates with the mouth wall  92  through a protruding lip  402 , sliding along the engagement wall  208 . 
     Moreover, head  20  comprises a connection element suitable for mechanically connecting the main body  200  of the valve dispenser element with frame  22 . 
     Preferably, said connection element comprises an auxiliary body  500 , made of a stiff material compared to the material which constitutes the main body of the valve dispenser element. For example, said auxiliary body is made of PP (polypropylene). 
     Preferably, the auxiliary body  500  comprises a base  502 , for example having a disc shape, and an annular coupling wall  504 , which axially extends from base  502 , for example in peripheral portion. 
     Moreover, the auxiliary body  500  comprises a tang  506 , protruding from base  502  towards container C, which defines a suction duct  507  in communication with compartment V of container C, provided with a tang gap  508  passing through base  502 . 
     Tang  506  is suitable for the insertion of a flexible suction pipe. 
     The coupling wall  504  of the auxiliary body  500  is coupled, for example snap-wise, with the connection wall  100  of the frame, so that membrane  202  of the valve dispenser element and in particular the residual portion  206  thereof, is kept abutting on the free end of said connection wall  100 . 
     In the embodiment variant which contemplates the secondary connection wall  112  ( FIG. 8  and following ones), the radial distance between said secondary connection wall  112  and the connection wall  100  is such as to allow the insertion and seating without radial interference of the coupling wall  504  of the auxiliary body  500 . 
     Moreover, according to such embodiment variant, the element connecting the main body  200  of the valve dispenser element to frame  22  are is integrated with a sealing element between the dispenser head  20  and neck N of container C. 
     For example, the auxiliary body  500  comprises a secondary annular sealing lip  510  arranged radially externally to the coupling wall  504 . Preferably, said secondary sealing lip  510  has a recessed bevel  512  at the free end to facilitate the insertion of neck N of container C in the access opening A. 
     In fact, once head  20  has been applied to container C, said secondary sealing lip  510  arranges itself in contact with the inner surface of neck N for implementing the seal between head  20  and said container C. 
     Preferably, said secondary sealing lip  510  consists of the end portion of a turned lip  514  which extends from base  502  of the auxiliary body  500 . Said turned lip  514  comprises a secondary coupling wall  516  which connects base  502  to the secondary sealing lip  510 , suitable for mechanically connecting, preferably snap-wise, with the secondary connection wall  112  of frame  22 . 
     Advantageously, the turned lip configuration increases the component elasticity, facilitating the insertion in the bottleneck, and improves the seal. 
     In an initial rest configuration ( FIG. 2 a   ), piston  26  is in the rest position and shutter  300  closes gap  212  of the feeding duct  210 , so that the pressure chamber  24  is separate from compartment V of container C and in particular from the suction duct  507  defined by tang  506 . 
     Moreover, membrane  202  is separate from the mouth wall  92 , while the engagement wall  208  is sealingly engaged with said mouth wall  92 , and in particular with the cylindrical portion  92   a ′ of the inner surface  92   a  thereof, so that the pressure chamber  24  is separate from the intermediate compartment  102  and thus from the dispenser duct  32 . 
     Admitting that an amount of liquid is already present in the pressure chamber  24 , by actuating the trigger, an active step is started in which piston  26  works in pressure in the pressure chamber  24 , trying to push the liquid out of the pressure chamber  24 , towards mouth  90 . 
     The liquid works on shutter  300  for closing the feeding duct  210  more powerfully; therefore, the liquid does not return into compartment V of the container through the suction duct  507 . 
     The liquid works on shutter  300  and on the surfaces of the feeding duct  210  developing an action which, deforming membrane  202 , makes the engagement wall  208  slide with respect to the mouth wall  92 . 
     The displacement of the engagement wall  208  is linked to the deformation of membrane  202 ; such deformation takes place in a particularly effective and repetitive manner since the membrane, in the rest configuration, is not engaged with the mouth wall  92 . 
     Therefore, in a first sub-step or pre-dispensing sub-step of the active step, the liquid pressure in the pressure chamber increases, but no liquid is yet dispensed to the outside since the engagement wall  208  is still sealingly in contact with the mouth wall  92 , so that the pressure chamber  24  is separate from the dispenser duct ( FIG. 2 b   ). 
     The sliding of the engagement wall  208 , due to the further deformation of membrane  202 , continues until, at the flared portion  92   a ″, passages  92   b ″ of the flared portion  92   a ″ open up, suddenly placing the pressure chamber  24  in communication with the intermediate compartment  102  and thus with the dispenser duct  32 . 
     Therefore, in a second sub-step or dispensing sub-step of the active step, the liquid is dispensed to the outside since passages  92   b ″ open up between the engagement wall  208  and the mouth wall  92 , so that the pressure chamber  24  is in communication with the dispenser duct ( FIG. 2 c   ). 
     The deformation of membrane  202  is limited by the auxiliary body  500 , and in particular by base  502  which forms a stiff abutment for said membrane  202 . 
     When the trigger is released, the elastic return element moves piston  26  or trigger  28  from the limit dispensing position towards the rest position. 
     The vacuum resulting in the pressure chamber  24  and the elastic return of membrane  202 , return the engagement wall  208  in sealed engagement with the mouth wall  92 , and in particular with the cylindrical portion  92   a ′ of the inner surface  92   a.    
     Moreover, the vacuum resulting in the pressure chamber  24  works on shutter  300  so as to open the feeding duct  210  towards the pressure chamber  24 . The liquid contained in compartment V of container C is thus drawn through tang  506 , the feeding duct  210  and mouth  90 , reaching the pressure chamber  24 . 
     At least by a stretch of the return step, the venting duct  110  is in communication with the external environment, so that the air may be drawn in compartment V of container C, before being closed again by the sealing lips  26   a ,  26   b  of piston  26 . 
     Innovatively, the dispenser according to the present invention allows a high behaviour repeatability of the dispenser to be obtained in dispensing, since the opening of the valve dispenser element is precise and repetitive, while keeping a simple structure thanks to the integration of the valve functions in few components. 
     In particular, advantageously, the device has a high operating repeatability especially in dispensing, mainly because the membrane, in the rest configuration, is not subject to any deformation since it is separate from the mouth wall. 
     Advantageously, moreover, the aesthetics of the device, defined for example by the shape of the cover or frame, may take several configurations. 
     This is mainly due to the position of the functional component of the device and in particular to the membrane position, which prevents structural interferences with the elements defining the aesthetics of the device, without detriment to the correct and functional sizing of the same. 
     Advantageously, moreover, the device operation is highly reliable since even strong pressures cause a controlled deformation of the membrane, limited by the auxiliary body. 
     According to a further advantageous aspect, the suction pipe connection is particularly easy and has no consequences on the functionality of the other parts of the valve dispenser element since the suction pipe is connected to the stiff auxiliary body. 
     It should be noted that a person of skill in the relevant art can make certain modifications to the invention by reference to the present description and Figures. Such modifications are intended to fit within the scope of protection as claimed herein.