Patent Publication Number: US-2012024983-A1

Title: Liquid Dispensing System

Description:
FIELD OF THE INVENTION 
     The present invention relates to an easy to use dispenser for liquid products, comprising a liquid holding reservoir connectable to a chamber for holding liquid under pressure and in turn connected to a spray arrangement for spraying the relevant liquid. The system of the invention is intended for the spraying of liquids selected from pesticides, such as herbicides, insecticides, fungicides, and others, house-hold cleaning products including for instance detergents, window cleaning products, carpet cleaning products or similar. 
     BACKGROUND OF THE INVENTION 
     Dispensers are generally well known in the art. Prior art dispensers of the general type typically include a bottle and a dispensing mechanism, for instance a trigger sprayer. The trigger sprayer may be attached to the bottle in any conventional way, e.g. by a threaded connection, a bayonet connection or a snap connection. Such trigger sprayers are well known in the art. 
     A problem with such dispensers is that those containers, when completely filled or filled to a substantial extent, are mostly uncomfortable to use as a result of the weight of the liquid contained therein. Also, most of these dispensers are intended to be used once and thrown in the waste when empty. 
     In the light of environmental concerns and also for reasons of cost reductions, reusable spray equipments have been proposed that can be connected to different containers or refill packs. Some others can be (re)loaded with diluted concentrates from refill packs or with ready-to-use liquids from refill packs, preferably environmentally friendly refill packs. 
     Known dispensers include squeeze bottles made of a rather flexible material and connected to a spray nozzle. The liquid contained in the bottle is pressurized by the squeezing of the bottle and liquid is released through the nozzle. Such arrangement is very simple and of low cost but leads to irregular spray patterns and leakage. 
     In the alternative, the liquid containing bottle is a more rigid bottle and pressurized by pumping air into it. The liquid under pressure then may be released through the sprayer. Here again, the spray pattern is not constant as it changes along with pressure reduction in the bottle in the course of use. Also, these equipments are generally rather heavy and inconvenient to use. 
     Another alternative is to mount a re-usable spray arrangement that includes a trigger sprayer on refill packs. In such cases, the refill packs need to comprise appropriate connection means and be of the appropriate shape, thus of relatively high cost and more likely to be less environmentally friendly than one-way refill packs. Such arrangements comprising trigger sprayers further require the user to accomplish inconvenient pumping actions with his or her finger and the spray volume per pumping movement is rather small, mostly around 1 ml. 
     EP-0814913 discloses a pump sprayer apparatus intended for being mounted on a liquid supply container suitable to contain pesticides, detergents or other liquid chemical compositions. The sprayer apparatus comprises a pump assembly, such as a positive displacement pump with a piston reciprocally movable in a cylinder, an inflatable accumulating bladder and a dispensing assembly. The piston raised by the user draws liquid from the supply container into the cylinder and then, when movement is reversed, pushes the said liquid into the inflatable bladder which accumulates the liquid under pressure. The energy accumulated into the expanded bladder may then be transferred to the liquid in an essentially constant manner when released from the bladder for discharge through the sprayer. One of the disadvantages of that system though is that it needs to be combined with a rather rigid supply container. In addition, the volume of the liquid ready to be dispensed through the sprayer is relatively small, thus allowing for a reduced number of sprays. 
     OBJECTS OF THE INVENTION 
     The present invention now seeks to provide a dispenser for liquid products selected from pesticides, such as herbicides, insecticides, fungicides, and others, house-hold cleaning products including for instance detergents, window cleaning products, carpet cleaning products or similar. 
     It is desired that the invention dispenser is easy to operate and of convenient use, while allowing for a comfortable spray volume prior to each recharging (in other words showing higher autonomy), more specifically adapted to the relevant use of the equipment. 
     It should advantageously be reusable by disconnection from the liquid holding reservoir and reconnection to a refill liquid holding reservoir. 
     Further objects and advantages will appear from the description herein. 
     SUMMARY OF THE INVENTION 
     The dispenser of the invention for liquid products comprises
         a removable liquid holding reservoir,   an essentially rigid chamber for holding liquid under pressure and comprising a spring and a piston to place liquid injected into said chamber under pressure,   a pump arrangement for pumping liquid from the liquid holding reservoir into the said chamber for holding liquid under pressure,   the pump being connected to the chamber through a one-way valve preventing liquid to flow from the chamber back into the pump arrangement   the chamber being connected to a spray nozzle through a valve controllable by the user for spraying said liquid.       

     Advantageously, the liquid holding reservoir may be a flexible, one-way refill pack. It may be connected to the pump arrangement by a flexible tube and a one-way valve that allows flow of liquid solely from the reservoir to the pump, thus avoiding liquid to escape from the pump. Or the pump arrangement can be connected directly to a one-way valve/closure on the liquid holding reservoir. 
     In a preferred embodiment, the pump arrangement comprises a cylinder of essentially circular section, one end of which is connectable to the liquid holding reservoir through a one-way valve that allows flow of liquid solely from the reservoir to the pump, and is further connected to the chamber through a one-way valve preventing liquid to flow from the chamber back into the pump cylinder, and a piston slidably mounted in the cylinder in a liquid tight manner, the piston being assembled with a rod extending through the opposite end of the cylinder into a handle for operation by the user. 
     Further embodiments and variations will become apparent from the description and drawings following hereafter. 
    
    
     
       SHORT DESCRIPTION OF THE DRAWINGS 
       The invention will now be illustrated with reference to the annexed drawings: 
         FIG. 1  is a schematic side view of the invention dispenser in an upright position; 
         FIG. 2  is a schematic view of a cross section along a longitudinal plane; 
         FIG. 3  is a top plane view of the dispenser of  FIG. 1 ; 
         FIG. 4  is a schematic side view analogous to the view of  FIG. 1 , showing different positions of movable parts; 
         FIG. 5  is a perspective view of a different embodiment of the invention; 
         FIG. 6  is a schematic view of a longitudinal cross-section of the embodiment of  FIG. 5 . 
         FIG. 7  is a schematic view of the arrangement of the valves, as well as of the flow of liquid between the individual elements of the invention dispenser; 
         FIGS. 8A and 8B  are exploded views from the top of the embodiment of  FIGS. 1-4 , the casing having been omitted; and 
         FIGS. 8C and 8D  are partial side views of the same embodiment as represented in  FIGS. 8A  and B, the casing being omitted in order to better represent schematically the internal connections. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the figures for a same embodiment, same reference numerals refer to the same element. The dispenser represented schematically in  FIGS. 1 to 4  constitutes a first embodiment of the invention. The dispenser  10  comprises a removable liquid holding reservoir (not represented) that can be connected to it under  2  by way of a flexible tube  1 , an essentially rigid chamber  20  for holding liquid under pressure and comprising a spring  22  acting on a piston  24  arranged at the bottom of the cylinder to place liquid injected into said chamber  20  under pressure, a pump arrangement  30  for pumping liquid from the liquid holding reservoir (not represented) into the said chamber  20  for holding liquid under pressure, the pump  30  being connected to the chamber  20  through a conduct  32  which incorporates a one-way valve (see description with respect of  FIG. 7  herein below), thus preventing liquid to flow from the chamber under pressure  20  back into the pump arrangement  30 . The chamber  20  is in turn connected to a spray nozzle  40  through a valve  42  controllable by the user by exerting pressure on a trigger button  44  for spraying said liquid stored in chamber  20 . The flexible tube connection  2  may advantageously be arranged at the top of the chamber  20 , preferably right underneath the nozzle  40 . In the alternative, the spring and the piston may be arranged at the top of the chamber  20  and the tube connector  2  is arranged at the bottom thereof. 
     In the case of a direct connection to the liquid holding reservoir, thus without flexible tube, this connector may also be placed at a location at the bottom of the chamber  20  or at the bottom of the handle. 
     The connector  2  may include the one-way valve  3  allowing liquid to flow from the external container to the pump  30  and preventing liquid to flow back into the liquid holding reservoir. 
     The dispenser  10  may advantageously be equipped with a handle  50  designed in such a way so as to facilitate holding of the device and spraying on target surface in ergonomically advantageous position or inclination. More specifically in the case of a dispenser of pesticides intended to be sprayed on target pests, such as weeds, the handle  50  may be inclined such as to ease directing the whole device loaded with liquid in a downward position. 
     The pump arrangement  30  comprises a cylinder  34  with a piston  36  of essentially circular section. One end of cylinder  34  is connectable to the liquid holding reservoir through a one-way valve  3  that allows flow of liquid solely from the reservoir to the pump  30 , and is further connected to the chamber  20  through a one-way valve  32  preventing liquid to flow from the chamber  20  back into the pump cylinder  34 . The piston  36  is slidably mounted in the cylinder  34  in a liquid tight manner, and is assembled with a rod  38  extending through the top end of the cylinder  30  into a handle  39  for operation by the user. According to the represented embodiment, the pump is arranged in an essentially parallel fashion to the cylindrical chamber  20  and adjacent to it. The handle  39  is arranged at the top of the dispenser or, expressed differently, at the same side as the spray nozzle  40 . 
     When lifting the handle  39  and hence piston  36  (see  FIG. 1 ), the user generates a depression in the cylinder  30  and liquid is extracted from the liquid holding reservoir into cylinder  30 , see  FIGS. 2 and 7 , following flow direction a. When pushing the handle  39  back down, the liquid stored in the cylinder  30  is expelled under pressure into the chamber  20 , through connections following flow direction b. The pressure of the liquid pushes piston  24  down, thus compressing the spring  22 . The energy stored in the spring allows to maintain the liquid under an essentially constant pressure in the chamber  20 . The user may repeat the same operation several times until the chamber  20  is essentially full. One may then disconnect the device  10  from the liquid holding container for instance by unscrewing or unplugging tube  1  at its connection  2  with the dispenser, and use the dispenser to apply the liquid as appropriate.  FIG. 7  schematically represents the flow of liquid and shows the operation of the one-way valves. When generating a depression in the pump cylinder  38 , one-way valve  3  opens to allow flow of liquid from the liquid holding reservoir  1  into the pump cylinder according to flow direction a. One-way valve  32  is closed by the depression. When expelling the liquid with the pump piston  36  according to flow direction b, valve  3  closes because of the pressure acting on the side of the pump but one-way valve  32  opens and allows flow of liquid into chamber  20  where said liquid is maintained under pressure. When releasing valve  42 , liquid under pressure may escape along direction c and finally d through nozzle  40 . 
     Chamber  20  may be designed to contain an adequate volume, thus giving the dispenser a reasonable autonomy. In the case of use for pesticide application, more specifically herbicide application, a volume of approximately 200 to 600 ml is advantageous. The volume of the pump arrangement  30 , i.e. cylinder  34 , is preferably adapted to the volume of the chamber  20 , in order for the user to fill chamber  20  after preferably  4 - 10  pumping operations. 
     One of the advantages of the invention arrangement is that the liquid to be sprayed is maintained in chamber  20  under an essentially constant pressure, thus allowing the user to preserve an essentially equal spray pattern all along the spraying operation. 
     Another advantage of the invention consists in the fact that the user bears a relatively light equipment with reasonable autonomy. Refill packs may be provided that are more environmentally friendly and need not consist in rigid containers. The invention equipment allows to conceive a liquid holding container for instance made of a flexible plastic bag with a rather small connection for tube  1 . Several volumes may be provided for, e.g. 1 l, 2 l, 5 l and more. Such containers may be filled with so-called ready-to-use spray solution. One may also provide for containers partially filled with a concentrate and that allow top-up with water or other diluents, thus allowing for reduced transportation costs and energy resources. 
     Nozzle  40  may advantageously be mounted on an essentially rigid tube also called lance  41  which in turn is advantageously slidably mounted in casing  11 . In addition, grips  45  may be fastened to the lance, advantageously on both sides thereof, and extend through casing  11  in order to facilitate the sliding of said lance  41 . 
     In a particularly preferred embodiment, the grips  45  interact with trigger button  44  in order to provide a child-safety arrangement. When nozzle  40  and thus grips  45  are in retracted position, said grips may block movement of the trigger button  44  and thus prevent opening of the release valve  42 . When sliding said grips outwardly in order to expend the lance  41 , the trigger button  44  is released and may be operated as appropriate in order to release liquid through the spray nozzle  40 . 
     Even more preferred, an additional child-resistance may be provided, such that preferably both grips  45  are in the form of a click assembly that snap into a counterpart on casing  11  in several (intermediate) locked positions of the lance  41  and that require pressure on one part of each grip  45  or a squeezing action to slightly buckle the relevant grips  45  or their link to the lance  41  in order to release said click assembly. 
       FIGS. 5 and 6  now represent a different embodiment of the invention. While the individual elements are essentially the same, they are assembled in a slightly different arrangement. The dispenser  110  comprises a removable liquid holding reservoir (not represented) that can be connected to it by way of a flexible tube  101 , an essentially rigid chamber  120  for holding liquid under pressure and comprising a spring  122  acting on a piston  124  to place liquid injected into said chamber  120  under pressure, a pump arrangement  130  for pumping liquid from the liquid holding reservoir (not represented) into the said chamber  120  for holding liquid under pressure, the pump  130  being connected to the chamber  120  through a conduct which incorporates a one-way valve, thus preventing liquid to flow from the chamber under pressure  120  back into the pump arrangement  130 . Here too, the chamber  120  is in turn connected to a spray nozzle  140  through a release valve  142  controllable by the user by exerting pressure on a trigger button  144  for spraying said liquid stored in chamber  120 . In the advantageous embodiment of  FIGS. 5 and 6 , the pump  130  is arranged in the form of a handle slightly inclined compared to the axis of the cylindrical chamber  120  and detached from it, while connected at the top end to the chamber  120  and the handle  139  extending through the opposite end of the pump. The tube connector  102  is then preferably arranged at the top of the cylindrical chamber  120 . The nozzle  140  then is arranged at the top of the pump, right next to the connector  102 . The dispenser  110  does not need a separate handle as the pump arrangement  130  is in the form of a handle already. The inclination of pump arrangement  130  and possibly of the spray nozzle  140  both compared to the axis of the essentially cylindrical chamber  120  may be designed in such a way so as to facilitate holding of the device and spraying on target surface in ergonomically advantageous position or inclination. More specifically in the case of a dispenser of pesticides intended to be sprayed on target pests, such as weeds, the inclination will be such as to ease directing the whole device loaded with liquid in a downward position. 
     As mentioned in relation to the embodiment described above, one may also provide for a direct connection between the liquid holding reservoir and the pump. In such a case, the connector  102  may be arranged at the bottom of the chamber  120  or at the bottom of the handle. 
     Contrary to the embodiment of  FIGS. 1 to 4 , the embodiment of  FIGS. 5 and 6  does not allow pumping operation when resting in upright position on a surface. Handle  139  needs to be pulled out downwardly to generate a depression in the pump for extracting liquid from the liquid holding reservoir. Pushing the handle  139  back into the handle pushes the liquid into chamber  120 . The pressure of the liquid pushes piston  124  down, thus compressing the spring  122 . The energy stored in the spring allows to maintain the liquid under an essentially constant pressure in the chamber  120 . The user may repeat the same operation several times until the chamber  120  is essentially full. One may then disconnect the device  110  from the liquid holding reservoir for instance by unscrewing or unplugging tube  101  at its connection  102  with the dispenser, and use the dispenser to apply the liquid as appropriate. 
     One of the advantages of the embodiment shown in  FIGS. 5 and 6  is that the nozzle  140  bearing lance may be longer as it may easily be arranged in parallel to either the pump  130  or chamber  120 . The connecting tube schematically represented with flow direction d then needs to extend up to the end of the lance opposite nozzle  140 . 
     The internal connections are essentially the same as per the embodiment of  FIGS. 1-4 . As can be seen from  FIG. 6 , liquid is extracted from the liquid holding reservoir through tube  101  and its connection to the pump cylinder  134  following direction a; it may then be expelled through tubular connections following direction b, into chamber  120 . Opening of the release valve  142  then finally allows liquid to escape passing through tubular connections c and d, as schematically represented in  FIG. 6 . 
     Turning now to  FIGS. 8A and 8C , nozzle  40  bearing lance  41  is shown in retracted position, blocking with corresponding grips  45 , and possibly an extension thereof, the movement of trigger button  44 , thus preventing release of spray liquid through release valve  42 . In order to better show the interaction of grips  45  with button  44 , the casing of the device has been omitted from the drawing. The tubular connection (d) is shown in a schematic way. In  FIGS. 8B and 8D , the nozzle  40  bearing lance  41  has been shown in extended position, the grips thus liberating button  44  which may thus be operated to spray liquid. As already mentioned, the grips  45  slide in the casing which has been omitted for the sake of clarity.