Patent Publication Number: US-8985401-B2

Title: Fluid discharge head

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of German Application No. 102008027600.6, entitled “Fluidaustragkopf,” filed 10 Jun. 2008, of German Application No. 102008027598.0, entitled “Fluidaustragkopf,” filed 10 Jun. 2008, and of International Application Number PCT/EP09/003,721, entitled “Fluidaustragkopf,” filed 26 May 2009, and incorporates each of those applications herein by reference in their entireties. 
     The invention relates to a fluid discharge head. 
     WO2007/009617 A1 discloses a fluid discharge head having a discharge nozzle which has a discharge opening and which holds an inner sleeve. Arranged in the inner sleeve is an inner body, which delimits an outlet duct and has a connecting element for providing a connection to the mating piece of a discharge device. At the front end adjacent to the discharge opening, the inner sleeve has a sealing face, against which a valve plug located on the inner body and closing the outlet duct is spring-prestressed. Therefore, a valve is integrated into the discharge head, in which the valve closure is implemented by a relative movement when actuated by the user. Such a valve can be dimensioned to be small. However, because of the problems of the fluid discharge head sucking back, security against penetration of germs and bacteria is not adequately provided. In order that no germs or other contaminants can penetrate into the system through the discharge opening, the use of oligodynamic substances can therefore be necessary. The use of such oligodynamic substances when conservation-medium-free media are employed is disadvantageous. 
     It is therefore an object of the invention to devise a fluid discharge head which permits an improved valve closure. 
     This object is achieved by the features of Claim  1 . 
     By this means, a fluid discharge head with a valve closure is devised in which the problems of sucking back as the valve is closed are eliminated by a positive pressure valve. A lightning closure directly after a spraying surge ensures that neither germs nor other contaminants can penetrate into the fluid discharge head through the medium outlet opening. The force for opening the valve is applied directly via the medium conveyed into the discharge head. An adjustable medium pressure opens the spring-loaded valve closure by moving the valve body counter to a spring force. The medium conveyed into the fluid discharge head by means of a discharge device is led into a closed and sealed space in the cylinder chamber, from which it flows to the medium outlet. The chamber applies a quantity of medium to the medium outlet, the medium surface of which, in conjunction with the medium forward pressure, opposes the penetration of bacteria and contaminants. Small dimensioning of the valve closure is possible. 
     The intermediate valve plate, on which the spring acts in order to press the valve body into the upper valve seat, preferably has a sealing strip to seal off the bottom of the cylinder chamber. Given an adequate medium pressure in the cylinder chamber, the bottom of which forms the intermediate valve plate, the upper valve seat lifts off when the force on the intermediate valve plate brought about by the medium forward pressure is greater than the spring force holding it closed. By means of the step-up ratio of the projected areas and of the rising pressure within the cylinder chamber, an influence can be exerted on the opening and closing behaviour. 
     The lower valve seat preferably has the function of a stuffing box packing for the medium duct, on which the moving lower end of the valve body bears in a sealing manner. 
     Further refinements of the invention can be gathered from the following description and the subclaims. 
    
    
     
       The invention will be explained in more detail below by using the exemplary embodiments illustrated in the appended figures. 
         FIG. 1  shows, schematically in section, a fluid discharge head according to a first exemplary embodiment, 
         FIG. 2  shows, schematically, the valve closure of the fluid discharge head according to  FIG. 1  in an enlarged illustration, 
         FIG. 3  shows the fluid discharge head according to  FIG. 2  with the valve closure open, 
         FIG. 4  shows, schematically in section, a fluid discharge head according to a second exemplary embodiment, 
         FIG. 5  shows the fluid discharge head according to  FIG. 4  with the valve closure open, 
         FIG. 6  shows, schematically, a plan view of the fluid discharge head according to  FIG. 4  with the discharge nozzle partly removed 
         FIG. 7  shows, schematically in section, a fluid discharge head according to a third exemplary embodiment, 
         FIG. 8  shows, schematically, the fluid discharge head according to  FIG. 7  with possible routes of the pressure drop. 
     
    
    
       FIGS. 1 to 3  show a fluid discharge head  1  for use with a discharge device  2 , the discharge device  2  comprising a medium store, not shown, for fluid, in which the medium is placed under pressure or from which the medium is discharged via a medium pump  3 , in particular a thrust piston pump. The discharge device  2  has a mating piece  4 , to which the fluid discharge head  1  can be fitted. The discharge device  2  with fluid discharge head  1  put in place forms a dispenser for in particular liquid media. 
     The fluid discharge head  1  and the discharge device  2  can be moved axially towards each other for the purpose of discharge actuation or shortening of the dispenser. When an actuating force is released, they return back in the opposite direction to the initial position according to  FIG. 1  by means of a spring F. 
     The fluid discharge head  1  comprises a discharge nozzle  5  having a discharge opening  6  which, here, is provided at the end of the discharge nozzle  5 . The discharge nozzle  5  holds an inner sleeve  7 , which delimits a medium duct  8  which adjoins a discharge section  26  of a medium guide  34  in the form of duct sections and/or medium spaces adjoining one another and located within the fluid discharge head  1 . 
     The inner sleeve  7  can additionally have a connecting element  9  for providing a connection to the mating piece  4  of the discharge device  2 . The inner sleeve  7  is formed in the shape of a pot at its end  11  facing the discharge opening  6 , in order to form a cylinder chamber  12  in conjunction with the front end  13  of the discharge nozzle  5 , which has the discharge opening  6 . To close the discharge opening  6 , the inner sleeve  7  holds a spring-loaded valve body  10  automatically closing the discharge opening  6 . 
     The valve body  10  is formed as a cylindrical piston, which can be displaced axially in the cylinder chamber  12  formed by the inner sleeve  7  on the top side. The movable valve body  10  subdivides the cylinder chamber  12  into an upper and a lower chamber section. The upper chamber section forms a pressure chamber  19 , which is connected to the medium duct  8  and can be opened and closed with respect to the discharge opening  6 . The lower chamber section is used to hold a spring element, in particular a compression spring  20 , for the pressure loading of the valve body  10 , in order that the latter closes the discharge opening  6  with a prestressing force as a spring-loaded valve body  10 . 
     For the valve body  10 , an upper valve seat  14  and a lower valve seat  15  are provided, which at the same time can serve as guide bearings for the piston ends  16 ,  17 . At least one of the two valve seats  14 ,  15  preferably serves as a guide bearing. The piston of the valve body  10  has an intermediate valve plate  18 , which forms a chamber bottom of the pressure chamber  19  connected to the medium duct  8 . The intermediate valve plate  18  seals off the pressure chamber  19  with respect to the upper valve seat  14 . The intermediate valve plate  18  is further preferably used to guide the movement of the valve body  10  in the cylinder chamber  12 . The intermediate valve plate  18  is preferably formed as a peripheral sealing lip, which guides the valve body  10  in the cylinder chamber  12  during its upward and downward movement. The intermediate valve plate  18  forms a chamber bottom of the pressure chamber  19 , which can be moved axially with respect to the discharge opening  6 , specifically as a result of movement of the valve body  10 . The volume content of the pressure chamber  19  consequently varies, the enlargement in volume during the opening of the discharge opening  6  being filled by the medium pressure in the passage duct  21 , so that no germs can penetrate. The reduction in the size of the volume content of the pressure chamber  19  as the discharge opening  6  is closed has the effect of a residual medium thrust, which prevents the penetration of germs. 
     To open the upper valve seat  14 , a medium discharge pressure which is higher than a spring force of the compression spring  20  holding the valve body  10  closed can be set in the pressure chamber  19 .  FIG. 1  and  FIG. 2  show a discharge opening  6  closed by the valve body  10 . 
     Medium flows through the valve body  10 , for which purpose the valve body  10  has a passage duct  21 , which connects the medium duct  8  to the pressure chamber  19 . The passage duct  21  is preferably led centrally through the valve body  10 . The passage duct  21  is formed by a rising tube section which, on the outlet side, preferably ends in an annular groove  22 , which leads the passage duct  21  over into the pressure chamber  19 . 
     The lower valve seat  15  preferably has the function of a stuffing box packing, in which a piston end  17  of the valve body  10 , broadened in the manner of a funnel, bears in a sealing manner, specifically during a downward and upward movement of the valve body  10 . 
     The upper valve seat  14  preferably comprises a slotted bush  24 , which is able to guide the upper piston end  16  during the opening and closing movement, but on the other hand permits flow towards the discharge opening  6  through bush slots when the upper piston end  16  having a preferably rounded sealing face  23  lifts off and opens the discharge opening  6  with respect to the pressure chamber  19 . The discharge opening  6  can have one or more openings, depending on which spray pattern or jet pattern is desired. The bush  24  can form a swirl chamber. 
     The bush  24  is preferably formed on the discharge nozzle  5  and, to this end, is made to be self-supporting. The pressure chamber  19  surrounds the discharge opening  6  with a forward-flow reservoir of fluid which, between the intermediate valve plate  18  and the upper valve seat  14 , provides a standing height of fluid as a forward-flow reservoir adjacent to the discharge opening  6 . Before the valve body  10  lifts off the upper valve seat  14 , the medium is present with a high initial pressure. This pilot pressure in the pressure chamber  19  is higher than the surrounding pressure, so that, when the discharge opening  6  is opened, the medium present emerges immediately. The pilot pressure is preferably set in a range between 1.5 and 2.3 bar. 
       FIG. 3  shows the opened discharge opening  6 . For this purpose, the valve body  10  has executed a movement away from the discharge opening  6 , which means that the sealing face  23  has lifted off. The medium present in the pressure chamber  19  then forces its way out of the discharge opening  6  through the chamber  28  formed between the top end of the valve body  10  and the front end  13  of the discharge nozzle  5 . The chamber  28  is preferably a swirl chamber. In this case, the quantity discharged is not restricted to the volume content of the pressure chamber  19 , since medium is conveyed as far as the end of a pump or pressure stroke via the passage duct  21  and is discharged. 
     The opening characteristic is determined by the step-up ratio of the projected areas F 1  and F 2 , F 1  being determined by the valve seat  15  for the lower piston end  17  and its diameter, while F 2  is determined by the pressure chamber  19  and the diameter of the intermediate valve plate  18 . F 3  determines the opening width of the discharge opening  6  in the region of the sealing face  23  at the upper piston end of the valve body  10 . 
     The compression spring  20  is inserted into the cylinder chamber  12  and is supported at one end on an underside of the intermediate valve plate  18  and a shoulder  27  of the cylinder chamber  12  adjacent to the valve seat  15 . 
     The valve body  10  can be displaced axially, counter to the spring force of the compression spring  20 , in order to open and close the upper valve seat  14 . The axial stroke can be limited by a spring compression and the spring force rising as a result and/or by a stop, which can be provided on the lower valve seat  15 . 
     The inner sleeve  7  is seated arranged fixedly in the discharge nozzle  5 , it being possible for the fixing to be made detachably via a snap-in connection. 
     The discharge nozzle  5  has finger contact surfaces  25  for manual actuation by applying actuating forces to the mating piece  4 . The medium duct  8  of the discharge nozzle  5 , which is used to pass on the fluid discharged from the medium container, adjoins a discharge section  26  in the form of a discharge duct belonging to the mating piece  4 . The opening width of the duct  26  can be chosen and can be matched to the desired delivery quantity via insert pieces. The ducts  26 ,  8  and  21  are preferably placed one above another along a central axis. 
     The discharge nozzle  5  here has the form of a nasal olive, in order to be able to be placed on the mating piece  4  as a nasal adapter. For other applications, the discharge nozzle  5  can have other external contours. 
       FIG. 4  to  FIG. 6  show a second exemplary embodiment of the fluid discharge head  1 , which differs from the first exemplary embodiment described previously in that the bush  24  here is formed on an inserted component  29 , which is fixed between the inner sleeve  7  and the upper end  13  of the discharge nozzle  5 . For this purpose, the component  29  can be provided in the manner of a spider with legs  30 , which can be used for positioning on the inner sleeve  7 . Furthermore, swirl ducts  31  can be formed on the bush  24  integrated into the component  29 . Via the swirl ducts  31 , a selectable spray pattern can be imparted to the medium emerging from the chamber  28 . 
     Furthermore, the second exemplary embodiment differs from the first exemplary embodiment in that the medium duct  8  joins a discharge section  26  in the form of a medium chamber, which is shut off or secured against a reverse flow of medium by a valve, in particular a ball valve  32 . The fluid discharge head  1  according to the invention can in this case be combined with a large number of different discharge and conveying systems  33 . 
     Otherwise, the above explanations relating to the first exemplary embodiment apply in a corresponding way to the second exemplary embodiment. 
     According to a third exemplary embodiment, as represented in  FIG. 7  and  FIG. 8 , a fluid discharge head  1  is devised which can be tested for leaks on the assembly line. This fluid discharge head is devised in which checking of various routes of the pressure drop is made possible. As a result, complete checking for tightness is possible. 
     For this it is provided a fluid discharge head having a discharge nozzle  5  having a discharge opening  6  and in which there is arranged an inner sleeve  7  which has a medium duct  8  and holds a spring-loaded valve body  10  which automatically closes the discharge opening  6  and, as an axially displaceable piston having an upper  14  and a lower valve seat  15  for the piston ends  16 ,  17 , is arranged in a pot-shaped end of the inner sleeve  7 . The pot-shaped end  11  forms a cylinder chamber  12  for the valve body  10  with an inner passage duct  21 , and the pot-shaped end  11  has a wall opening  42  between the cylinder chamber  12  and an interior  43  of the discharge nozzle  5 . 
     The pot-shaped end  11  has a wall opening  42  between the cylinder chamber  12  and an interior  43  of the discharge nozzle  5 .  FIG. 8  shows the sealing points that can be checked and the possible routes of the pressure drop V 1 , V 2  and V 3  in the event of leaks. For this purpose, an air pressure P is applied in the direction of the medium guide  47  (cf.  FIG. 7 ). If the intermediate valve plate  18  does not seal off with respect to the upper valve seat  14  and/or the valve seat  15  does not seal, air penetrates through the wall opening  42  into the interior  43  and can be measured as a pressure drop V 2 . Leaks in the region of the valve seat  14  can be measured as a pressure drop V 1 . Leaks between the inner sleeve  7  and the discharge nozzle  5  can be measured as a pressure drop V 3 . 
     At the pot-shaped end  11 , the fluid discharge head  1  also has an external cam  44  which, as a stop, interacts with a rib  45  on an inner wall  48  of the discharge nozzle  5  during a movement of the inner sleeve  7  that is directed axially upwards. 
     The medium duct  8  of the discharge nozzle  5 , which is used to forward the fluid discharged from the medium container, adjoins a discharge section  26  in the form of a discharge duct belonging to the mating piece  4 . The opening width of the duct  26  can be chosen and can be matched to the desired delivery quantity via insert pieces. The ducts  26 ,  8  and  21  are preferably placed one above another along a central axis. 
     The discharge nozzle  5  here has the form of a nasal olive, in order to be able to be placed on the mating piece  4  as a nasal adapter. For other applications, the discharge nozzle  5  can have other external contours. 
     Otherwise, the above explanations relating to the first and second exemplary embodiment apply in a corresponding way to the fluid discharge head.