Fluid discharge head

Fluid discharge head having a discharge nozzle (5) which has a discharge opening (6) in which an inner sleeve (7) is arranged, which has a medium duct (8) and holds a spring-loaded valve body (10) automatically closing the discharge opening (6), the valve body (10) being formed as a cylindrical piston, which can be displaced axially in a cylinder chamber (12) formed by the inner sleeve (7), an upper (14) and a lower valve seat (15) being provided for the piston ends (16, 17), and the valve body (10) having an intermediate valve plate (18), which forms a chamber bottom of a pressure chamber (19) connected to the medium duct (8), and, in order to open the upper valve seat (14), a medium discharge pressure which is higher than a spring force holding the valve body (10) closed can be set in the pressure chamber.

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 Claim1.

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.

FIGS. 1 to 3show a fluid discharge head1for use with a discharge device2, the discharge device2comprising 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 pump3, in particular a thrust piston pump. The discharge device2has a mating piece4, to which the fluid discharge head1can be fitted. The discharge device2with fluid discharge head1put in place forms a dispenser for in particular liquid media.

The fluid discharge head1and the discharge device2can 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 toFIG. 1by means of a spring F.

The fluid discharge head1comprises a discharge nozzle5having a discharge opening6which, here, is provided at the end of the discharge nozzle5. The discharge nozzle5holds an inner sleeve7, which delimits a medium duct8which adjoins a discharge section26of a medium guide34in the form of duct sections and/or medium spaces adjoining one another and located within the fluid discharge head1.

The inner sleeve7can additionally have a connecting element9for providing a connection to the mating piece4of the discharge device2. The inner sleeve7is formed in the shape of a pot at its end11facing the discharge opening6, in order to form a cylinder chamber12in conjunction with the front end13of the discharge nozzle5, which has the discharge opening6. To close the discharge opening6, the inner sleeve7holds a spring-loaded valve body10automatically closing the discharge opening6.

The valve body10is formed as a cylindrical piston, which can be displaced axially in the cylinder chamber12formed by the inner sleeve7on the top side. The movable valve body10subdivides the cylinder chamber12into an upper and a lower chamber section. The upper chamber section forms a pressure chamber19, which is connected to the medium duct8and can be opened and closed with respect to the discharge opening6. The lower chamber section is used to hold a spring element, in particular a compression spring20, for the pressure loading of the valve body10, in order that the latter closes the discharge opening6with a prestressing force as a spring-loaded valve body10.

For the valve body10, an upper valve seat14and a lower valve seat15are provided, which at the same time can serve as guide bearings for the piston ends16,17. At least one of the two valve seats14,15preferably serves as a guide bearing. The piston of the valve body10has an intermediate valve plate18, which forms a chamber bottom of the pressure chamber19connected to the medium duct8. The intermediate valve plate18seals off the pressure chamber19with respect to the upper valve seat14. The intermediate valve plate18is further preferably used to guide the movement of the valve body10in the cylinder chamber12. The intermediate valve plate18is preferably formed as a peripheral sealing lip, which guides the valve body10in the cylinder chamber12during its upward and downward movement. The intermediate valve plate18forms a chamber bottom of the pressure chamber19, which can be moved axially with respect to the discharge opening6, specifically as a result of movement of the valve body10. The volume content of the pressure chamber19consequently varies, the enlargement in volume during the opening of the discharge opening6being filled by the medium pressure in the passage duct21, so that no germs can penetrate. The reduction in the size of the volume content of the pressure chamber19as the discharge opening6is closed has the effect of a residual medium thrust, which prevents the penetration of germs.

To open the upper valve seat14, a medium discharge pressure which is higher than a spring force of the compression spring20holding the valve body10closed can be set in the pressure chamber19.FIG. 1andFIG. 2show a discharge opening6closed by the valve body10.

Medium flows through the valve body10, for which purpose the valve body10has a passage duct21, which connects the medium duct8to the pressure chamber19. The passage duct21is preferably led centrally through the valve body10. The passage duct21is formed by a rising tube section which, on the outlet side, preferably ends in an annular groove22, which leads the passage duct21over into the pressure chamber19.

The lower valve seat15preferably has the function of a stuffing box packing, in which a piston end17of the valve body10, broadened in the manner of a funnel, bears in a sealing manner, specifically during a downward and upward movement of the valve body10.

The upper valve seat14preferably comprises a slotted bush24, which is able to guide the upper piston end16during the opening and closing movement, but on the other hand permits flow towards the discharge opening6through bush slots when the upper piston end16having a preferably rounded sealing face23lifts off and opens the discharge opening6with respect to the pressure chamber19. The discharge opening6can have one or more openings, depending on which spray pattern or jet pattern is desired. The bush24can form a swirl chamber.

The bush24is preferably formed on the discharge nozzle5and, to this end, is made to be self-supporting. The pressure chamber19surrounds the discharge opening6with a forward-flow reservoir of fluid which, between the intermediate valve plate18and the upper valve seat14, provides a standing height of fluid as a forward-flow reservoir adjacent to the discharge opening6. Before the valve body10lifts off the upper valve seat14, the medium is present with a high initial pressure. This pilot pressure in the pressure chamber19is higher than the surrounding pressure, so that, when the discharge opening6is opened, the medium present emerges immediately. The pilot pressure is preferably set in a range between 1.5 and 2.3 bar.

FIG. 3shows the opened discharge opening6. For this purpose, the valve body10has executed a movement away from the discharge opening6, which means that the sealing face23has lifted off. The medium present in the pressure chamber19then forces its way out of the discharge opening6through the chamber28formed between the top end of the valve body10and the front end13of the discharge nozzle5. The chamber28is preferably a swirl chamber. In this case, the quantity discharged is not restricted to the volume content of the pressure chamber19, since medium is conveyed as far as the end of a pump or pressure stroke via the passage duct21and is discharged.

The opening characteristic is determined by the step-up ratio of the projected areas F1and F2, F1being determined by the valve seat15for the lower piston end17and its diameter, while F2is determined by the pressure chamber19and the diameter of the intermediate valve plate18. F3determines the opening width of the discharge opening6in the region of the sealing face23at the upper piston end of the valve body10.

The compression spring20is inserted into the cylinder chamber12and is supported at one end on an underside of the intermediate valve plate18and a shoulder27of the cylinder chamber12adjacent to the valve seat15.

The valve body10can be displaced axially, counter to the spring force of the compression spring20, in order to open and close the upper valve seat14. 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 seat15.

The inner sleeve7is seated arranged fixedly in the discharge nozzle5, it being possible for the fixing to be made detachably via a snap-in connection.

The discharge nozzle5has finger contact surfaces25for manual actuation by applying actuating forces to the mating piece4. The medium duct8of the discharge nozzle5, which is used to pass on the fluid discharged from the medium container, adjoins a discharge section26in the form of a discharge duct belonging to the mating piece4. The opening width of the duct26can be chosen and can be matched to the desired delivery quantity via insert pieces. The ducts26,8and21are preferably placed one above another along a central axis.

The discharge nozzle5here has the form of a nasal olive, in order to be able to be placed on the mating piece4as a nasal adapter. For other applications, the discharge nozzle5can have other external contours.

FIG. 4toFIG. 6show a second exemplary embodiment of the fluid discharge head1, which differs from the first exemplary embodiment described previously in that the bush24here is formed on an inserted component29, which is fixed between the inner sleeve7and the upper end13of the discharge nozzle5. For this purpose, the component29can be provided in the manner of a spider with legs30, which can be used for positioning on the inner sleeve7. Furthermore, swirl ducts31can be formed on the bush24integrated into the component29. Via the swirl ducts31, a selectable spray pattern can be imparted to the medium emerging from the chamber28.

Furthermore, the second exemplary embodiment differs from the first exemplary embodiment in that the medium duct8joins a discharge section26in 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 valve32. The fluid discharge head1according to the invention can in this case be combined with a large number of different discharge and conveying systems33.

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 inFIG. 7andFIG. 8, a fluid discharge head1is 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 nozzle5having a discharge opening6and in which there is arranged an inner sleeve7which has a medium duct8and holds a spring-loaded valve body10which automatically closes the discharge opening6and, as an axially displaceable piston having an upper14and a lower valve seat15for the piston ends16,17, is arranged in a pot-shaped end of the inner sleeve7. The pot-shaped end11forms a cylinder chamber12for the valve body10with an inner passage duct21, and the pot-shaped end11has a wall opening42between the cylinder chamber12and an interior43of the discharge nozzle5.

The pot-shaped end11has a wall opening42between the cylinder chamber12and an interior43of the discharge nozzle5.FIG. 8shows the sealing points that can be checked and the possible routes of the pressure drop V1, V2and V3in the event of leaks. For this purpose, an air pressure P is applied in the direction of the medium guide47(cf.FIG. 7). If the intermediate valve plate18does not seal off with respect to the upper valve seat14and/or the valve seat15does not seal, air penetrates through the wall opening42into the interior43and can be measured as a pressure drop V2. Leaks in the region of the valve seat14can be measured as a pressure drop V1. Leaks between the inner sleeve7and the discharge nozzle5can be measured as a pressure drop V3.

At the pot-shaped end11, the fluid discharge head1also has an external cam44which, as a stop, interacts with a rib45on an inner wall48of the discharge nozzle5during a movement of the inner sleeve7that is directed axially upwards.

The medium duct8of the discharge nozzle5, which is used to forward the fluid discharged from the medium container, adjoins a discharge section26in the form of a discharge duct belonging to the mating piece4. The opening width of the duct26can be chosen and can be matched to the desired delivery quantity via insert pieces. The ducts26,8and21are preferably placed one above another along a central axis.

The discharge nozzle5here has the form of a nasal olive, in order to be able to be placed on the mating piece4as a nasal adapter. For other applications, the discharge nozzle5can 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.