Patent Publication Number: US-11033913-B2

Title: Dispensing head with a stepped swirling chamber for a dispensing device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119(a) to French Patent Application Serial Number 1851712, filed Feb. 27, 2018, the entire teachings of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a spraying device, in particular for a system for dispensing a product provided with a push-button. 
     Description of the Related Art 
     In a particular application, the dispensing system is intended to be provided on bottles used in perfumery, cosmetics or for pharmaceutical treatments. Indeed, this type of bottle contains a product which is supplied by the dispensing system including a device for collecting the product, the system being actuated for example by a push-button in order to allow for the spraying of the product. In general, the device for collecting includes a pump or a valve with manual actuation, for example by means of the push-button. 
     Such push-buttons are conventionally made of two portions, of which one is an actuating body and one a spraying nozzle, both being assembled one to the other. The nozzle generally includes a swirling chamber provided with a dispensing orifice, as well as at least one supply channel of the chamber. 
     The device for collecting samples the product from the bottle via a dip tube, and pushes it inside the duct arranged in the plunger, which is the actuating element of the collecting device. This duct opens into a so-called swirling chamber intended to rotate the liquid very quickly and therefore to give it the speed and the effects of centrifugal force. This swirling chamber is extended at its center by an outlet orifice through which the product escapes outside at a high speed. Moved by this speed, and subjected to the centrifugal forces, the liquid breaks up into droplets and forms an aerosol. The size of the droplets coming from the swirling chamber partially depends on the force and on the speed with which the user actuates the pump by pressing on the push-button with their finger, as the induced pressure depends on this. 
     In order to ensure good uniformity of the size of the droplets, one technology consists in using a revolution swirling chamber. Thus, the flow rotates in the chamber in the form of a sheet that is impacted on itself after the exiting therefrom through the dispensing orifice. 
     This technology is used for products that are not viscous or hardly viscous. 
     When the product is viscous, typically with about 50 or 100 times the viscosity of water, the impaction of the sheets does not occur correctly, for example when the viscosity is greater than 150 mPa·s. This results in an excessively large size of the droplets and the cone of sprayed product is then of poor quality. 
     In order to improve the cone of the sprayed product, when the product is viscous, one technology consists in adding steps in the swirling chamber. 
     The steps make it possible to improve the impaction of the sheets of product and to obtain droplets of small dimensions with a viscous product. 
     Although this technology improves the sprayed cone, a disadvantage remains. Indeed, the dimensions of the droplets are suitable in most of the sprayed cone which makes it possible to obtain a cone of fine droplets of product. However, a central zone of the cone does not have the needed requirements. This central zone is located immediately downstream from the dispensing orifice in the direction of displacement of the product, and extends substantially in a straight line. In this central zone, the droplets have dimensions that are much greater than in the rest of the cone. Frequently, a continuous stream in a central zone coexists with the peripheral droplets. In other words, the dimensions of the droplets are not uniform in the cone. 
     A user then receives, on their hands or another part of their body, product in the form of a continuous stream in the central zone, amongst a cone of fine droplets. The experience of the product is consequently altered. This is all the truer with customers whose expectations are often high. In addition to the unpleasant sensation that the continuous stream produces, the latter reflects a poor image of the product and of its manufacturer, despite the cosmetic qualities that it contains. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention relates to a dispensing head, in particular for a system for dispensing a product. The head includes a spraying nozzle including a dispensing orifice and a swirling chamber opening into the dispensing orifice, the swirling chamber including a converging portion, the swirling chamber extending along an axis, between an upstream end and a downstream end in the direction of displacement of the product, an anvil including a core provided with a peripheral wall, the core being housed inside the swirling chamber, the peripheral wall and the converging portion forming at least one fluidic path in which the product circulates. The converging portion includes an inner wall of the nozzle, the inner wall and/or the peripheral wall of the core is provided with a plurality of steps, each step being defined by a transverse wall that extends in a plane secant to the axis and a longitudinal wall substantially parallel to the axis, the steps forming obstacles in the fluidic path. 
     This dispensing head has the advantage of eliminating the continuous stream that appears in the central zone. This is made possible by the combined action of the converging portion provided with steps and of a core forming at least one fluidic path wherein the product encounters obstacles. This is also made possible by the combined action of the converging portion and of a core provided with steps as well as a converging portion and a core, both provided with steps. The dispensing head is particularly advantageous when the product has a non-Newtonian rheological behaviour. This type of fluid is fluidified as the rate of shearing increases. This type of product is widely used in the cosmetics industry. The central zone then includes droplets of which the dimensions are substantially identical in the entire cone. 
     According to various embodiments of the invention, that can be taken together or separately:
         the converging portion includes at least one step nosing located at the junction between a transverse wall and a longitudinal wall, the step nosing being located at a proximal distance of between 70 and 250 micrometres from the peripheral wall of the core measured along an imaginary straight line traced from the step nosing to the peripheral wall following the shortest route;   a length of the longitudinal wall is between 30 and 250 micrometres measured along the axis;   a length of the transverse wall is between 30 and 350 micrometres measured along an axis orthogonal to the axis;   the steps extend from the upstream end to the downstream end;   the converging portion includes between three and fifteen steps, preferably four steps;   the swirling chamber includes a pre-chamber upstream from the converging portion;   the nozzle includes at least one supply channel of the swirling chamber;   the channel or channels open into the pre-chamber;   the pre-chamber is annular;   the height of the channel or channels corresponds to the height of the pre-chamber;   the channel or channels open tangentially into the swirling chamber;   the core includes a cone-shaped portion revolving about the axis and defines a top located opposite the dispensing orifice;   the top is flat and includes a planar wall substantially perpendicular to the axis;   the core is solid;   the dispensing orifice is only connected fluidically to the converging portion of the nozzle.   The invention also relates to a system for dispensing a product including a dispensing head such as described hereinabove.       

     Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. The embodiments illustrated herein are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein: 
         FIG. 1  is a two-dimensional cross-section view of a dispensing head according to the invention; 
         FIG. 2  is a perspective and cross-section view of a dispensing nozzle of the dispensing head of  FIG. 1 ; 
         FIG. 3  is a perspective view of the dispensing head of  FIG. 1  without the dispensing nozzle; 
         FIG. 4  is a two-dimensional view of the dispensing nozzle of  FIGS. 1 and 2 ; 
         FIG. 5  is a view similar to  FIG. 1  of a second embodiment; 
         FIG. 6  is a view similar to  FIG. 2  of the second embodiment of  FIG. 5 ; 
         FIG. 7  is a view similar to  FIG. 3  of the second embodiment; 
         FIGS. 8 a , 8 b , 8 c , 8 d , 8 e , 8 f , 8 g    diagrammatically show alternative embodiments wherein the nozzle includes steps; 
         FIGS. 9 a , 9 b , 9 c , 9 d , 9 e , 9 f , 9 g    diagrammatically show alternative embodiments wherein a core includes steps; 
         FIGS. 10A, 10B, 10B, 10C, 10D, 10E, 10F, 10G  diagrammatically show alternative embodiments wherein the nozzle and the core include steps. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a dispensing head  1 , in particular for a system for dispensing (not shown) a fluid product. 
     The dispensing system includes the dispensing head  1  and a device for collecting (not shown) provided with a feed tube inserted into a well  2  located in the dispensing head  1 . 
     In the rest of the description, by convention the direct orthogonal coordinate system defined as follows is used: 
     an axis X defining a first direction, which corresponds to the axis of a swirling chamber of the dispensing head  1 , 
     an axis Y orthogonal to the X axis and defining a second direction as well as a plane XY, 
     an axis Z orthogonal to both the Y axis and to the X axis and defining a third direction as well as planes ZY and ZX. 
     The dispensing head  1  includes a body  3 . The body  3  defines a support wall  4  located on an upper portion of the latter. The support wall  4  allows the user to press the dispensing head  1  in order to spray the product. 
     As shown in  FIG. 3 , the body  3  defines a housing  6 . The housing  6  is in fluidic communication with the well  2 . This fluidic communication is achieved through an inner channel  27  made in the body  3 . 
     The body  3  includes an anvil  8 . More preferably, the anvil  8  is made from a single piece with the dispensing head  1 . The anvil  8  extends longitudinally according to the X axis into the housing. The anvil  8  has a circular section in the plane ZY. 
     The anvil  8  includes a core  9  visible in  FIGS. 1 and 3 . The core  9  has the form of an element protruding according to the X axis from a distal surface  10  of the anvil  8 . 
     The core  9  includes a cylindrical portion  11 . The cylindrical portion  11  is located at the base of the core and is adjacent to the distal surface  10  of the anvil  8 . The core  9  includes a cone-shaped portion  12  revolving about the axis X. The conical portion  12  extends from the cylindrical portion  11  and finishes with a top  13 . The top  13  is flat. The top  13  has the form of a planar wall substantially perpendicular to the axis X. 
     The cylindrical portion  11  and the conical portion  12  together form a peripheral wall  36  of the core  9 . 
     The dispensing head  1  includes a spraying nozzle  14 . The spraying nozzle  14  is an element added on the dispensing head  1 . The spraying nozzle  14  includes an annular wall  15  forming a volume open on one side and closed on the other by a distal wall  16 . The spraying nozzle  14  defines a central opening  17  laterally bordered according to the axes Y and Z by the annular wall  15  and longitudinally according to the X axis by the distal wall  16 . The annular wall  15  includes a locking tab  18 . The locking tab  18  has the form of a protruding annular edge, which extends along the perimeter of the annular wall  15 . 
     The distal wall  16  includes a dispensing orifice  19  and a swirling chamber  20 . The swirling chamber  20  opens into the dispensing orifice  19 . The swirling chamber  20  revolves about the axis X. More precisely, the swirling chamber  20  includes a converging portion  37 . The swirling chamber  20  includes an inner wall  35  and extends from an upstream end  21  coinciding with an inner surface  23  of the distal wall  16  to a downstream end  22 . The downstream end  22  can easily be located by being positioned in the dispensing orifice  19  and then by being displaced according to the X axis from an outer surface  24  of the distal wall  16 . The dispensing orifice  19  is a revolving cylinder, thus the section of the latter is substantially constant. The location where the section begins to vary is the border between the dispensing orifice  19  and the swirling chamber  20 , namely the downstream end  22 . 
     In an alternative embodiment not shown, the downstream end  22  of the swirling chamber  20  is the dispensing orifice  19 . In other terms, the dispensing orifice  19  coincides with the downstream end  22 . 
     In an alternative embodiment not shown in the figures, only a portion of the swirling chamber  20  revolves. 
     In the shown embodiment, the swirling chamber  20  further includes a pre-chamber  50 , located upstream from the converging portion  37  of the swirling chamber. The pre-chamber  50  is here annular. It is delimited by the cylindrical portion  11  of the core  9 , the portion opposite the distal wall  16  of the nozzle, the distal surface  10  of the anvil and the converging portion  37  of the swirling chamber. Thus, the upstream end of the chamber  20  corresponds to the upstream end of the pre-chamber  50 . 
     The dispensing nozzle  14  includes at least one supply channel  25  of the swirling chamber  20 . In the preferred embodiment shown in the figures, the dispensing nozzle  14  includes two supply channels  25 . The supply channels  25  are made in the distal wall  16 . 
     The supply channels  25  open tangentially into the annular pre-chamber  50  belonging to the swirling chamber  20 . They could open along any other orientation. In particular, the channels  25  could open according to a direction tangential to the first step  30 , immediately downstream from the pre-chamber  50 . The pre-chamber  50  allows for the rotation of the product around the cylindrical portion  11  of the core  9 . The annular pre-chamber  50  has a length measured along the axis X equal to a depth of the supply channels  25  measured along the axis X. The annular pre-chamber  50  is not a step in the sense of the invention. 
     As mentioned hereinabove, the spraying nozzle  14  is a separate element added on the dispensing head  1 . More precisely, the spraying nozzle  14  is inserted into the housing  6  and fixed to the body  3  thanks to the locking tab  18  embedded into the body  3 . 
     As shown in  FIG. 1 , the anvil  8  is partially arranged in the central opening  17  of the nozzle in such a way that the distal surface  10  is in abutment on the inner surface  23 . The core  9  is thus housed inside the swirling chamber  20 . The peripheral wall  36  of the core  9  and the converging portion  37  of the swirling chamber  20  form a fluidic path in which the product coming from the supply channel  25  circulates. 
     As can be seen in  FIGS. 1 and 2 , the converging portion  37  of the swirling chamber  20  includes a plurality of steps  30 . A step  30  is defined by a transverse wall  31  and a longitudinal wall  32 . 
     The transverse wall  31  extends in a plane secant to the X axis. Indeed, by extending the transverse wall  31  in the direction of the X axis using an imaginary straight line in  FIG. 1 , the latter cuts the X axis. The longitudinal wall  32  is substantially parallel to the axis X. By extending the longitudinal wall  32  on either side to infinity with an imaginary straight line, the latter is substantially parallel to the axis X. 
     In this configuration, the steps  30  form obstacles in the fluidic path. More precisely, the transverse walls  31  of the steps  30  form obstacles in the fluidic path. 
     The combination of the steps  30  and of a core  9  that extends in the swirling chamber  20  makes it possible to eliminate the continuous stream that appears in a central zone  28  of a cone  29  of droplets sprayed at the output of the dispensing orifice  19 . In other words, the combination of the core  9  and the steps  30  forming obstacles in the fluidic path advantageously makes it possible to obtain in the central zone  28  droplets that have dimensions that are identical or otherwise similar to the droplets present in the rest of the sprayed cone  29 . Thus the dimensions of the droplets in the cone  29  are substantially uniform. 
     In a preferred embodiment of the invention, the transverse walls  31  are substantially orthogonal to the X axis. The impact with the product in the fluidic path is then sudden, which results in a better impaction of the product on the steps  30 . 
     In an alternative embodiment not shown, the transverse walls  31  are not orthogonal. In this latter case the energy of the impact between the product and the transverse walls  31  is not as high. The energy of the impact of the product against the steps  30  can be adjusted by modifying the angle that the transverse walls  31  form with the X axis. 
     Each transverse wall  31  crosses at each one of its ends a longitudinal wall  32 . In what follows, these intersections are referred to as step nosing  33  and step hollows  34  according to their separation in the plane ZY of the peripheral wall  36  of the core  9 . 
     In a preferred embodiment, the step nosing  33  is located at a proximal distance of between 70 and 250 micrometres from the peripheral wall  36  of the core  9 . In  FIG. 1 , this proximal distance is measured along an imaginary straight line traced from the step nosing  33  to the peripheral wall  36  following the shortest route. More preferably the proximal distance is of about 160 micrometres. 
     The proximal distance providing the interval mentioned hereinabove and more particularly the specific values indicated, allow for shearing of the product that is sufficient in the vicinity of the step nosing  33  against the peripheral wall  36  of the core  9 . This results in a localised increase in the rate of shearing induced by the peripheral wall  36  in the vicinity of the step nosing  33  that makes it possible to reduce the viscosity of the product. In other terms, this makes it possible to fluidify the product. 
     It has been determined that a length of between 30 and 350 micrometres for the transverse wall  31  measured along the axis Y in  FIG. 1  and in the plane ZY in perspective, is particularly effective. It has also been determined that a length of between 30 and 250 micrometres for the longitudinal wall  32  according to the X axis in  FIG. 1  and in the plane ZX in perspective is particularly effective. 
     In a preferred embodiment shown in the figures, the converging portion  37  of the swirling chamber  20  includes between three and fifteen steps  30  and preferably four steps  30 . Thus, the converging portion  37  includes more preferably four transverse walls  31  and four longitudinal walls  32 . This makes it possible to obtain significant results with a total elimination that is otherwise quasi-total of a continuous stream in the central zone  28 . 
     Advantageously, the core  9  is arranged inside the swirling chamber  20  in such a way that any point of the planar wall is located at a predetermined distance from the downstream end of between 100 and 300 micrometres, and more preferably of about 200 micrometres. This distance is particularly advantageous as it allows for an optimum evacuation of the product in that the product is both correctly fluidified on the one hand and it limits the load loss when circulating in the fluidic path. 
     The core  9  and more precisely the planar wall is arranged next to the dispensing orifice  19  in such a way that the core defines an obstacle to any intrusion from the external environment by the dispensing orifice  19  in such a way as to not obstruct the ducts. 
     Advantageously the core  9  of the anvil  8  is solid. In other terms, the core  9  does not include any orifice whatsoever that opens for example onto the external environment on the one hand and onto the swirling chamber  20  on the other hand or onto any portion whatsoever of the housing  6 . 
     Advantageously the dispensing orifice  19  is only connected fluidically to the converging portion  37 . In other terms, the dispensing nozzle  14  does not include any channel or output that connects the swirling chamber  20  or the housing  6  to the external environment, for example when it is mounted on the body  3 . 
     This advantageously makes it possible to maintain the favourable pressure conditions in the swirling chamber  20  and more globally in the housing  6  on the one hand and to prevent any bacterial contamination with the external environment on the other hand. 
     In an alternative embodiment shown in  FIGS. 5 to 7 , the swirling chamber  20  is longer along the X axis than that of the embodiment shown in  FIGS. 1 to 4 . 
       FIGS. 8 a  to 8 g    show embodiments wherein the steps are arranged on the nozzle. 
       FIGS. 9 a  to 9 g    show embodiments wherein the steps are arranged on the core. 
       FIGS. 10 a  to 10 g    show embodiments wherein the steps are arranged on the nozzle and on the core. 
       FIGS. 8 a , 9 a  and 10 a    show alternatives wherein longitudinal and transverse walls are approximately the same dimension. 
       FIGS. 8 b , 9 b  and 10 b    show alternatives wherein longitudinal and transverse walls are of different dimensions. 
       FIGS. 8 c , 9 c  and 10 c    show alternatives wherein the longitudinal wall located most downstream according to the displacement of the fluid is longer than the other longitudinal walls located further upstream. 
       FIGS. 8 d , 9 d  and 10 d    show alternatives wherein any longitudinal wall is longer than the other longitudinal walls. 
       FIGS. 8 e , 9 e  and 10 e    show alternatives wherein the fluidic path is divergent. 
       FIGS. 8 f , 9 f  and 10 f    show alternatives wherein the fluidic path is convergent. This alternative is particularly interesting as it allows for an increasing rate of shearing in the upstream to downstream direction according to the displacement of the product. 
       FIGS. 8 g , 9 g  and 10 g    show alternatives wherein a planar intermediate section  51  separates two groups of steps  53 . 
     In an alternative embodiment not shown in the figures, the steps can be arranged by angular sector. In other terms, the steps extend uninterruptedly around the perimeter of the converging portion  37  of the swirling chamber  20  and/or of the peripheral wall  36  of the core  9 . In this alternative, the core  9  and/or the swirling chamber  20  include at least two groups of steps separated by smooth walls. 
     The invention also relates to a system for spraying a product including a dispensing head  1  such as described hereinabove. 
     Having thus described the invention of the present application in detail and by reference to embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims as follows: