Discharger for a flowable medium

Abstract

1. Discharger. 2.1. The invention relates to a discharger for a flowable medium, comprising a discharge sleeve (20), at whose one end there is provided a discharge opening (22) for discharging the medium, and a closing pin (30), which is provided in the discharge sleeve (20) and is longitudinally displaceable relative to the discharge sleeve (20) and by which the discharge opening (22) can be closed off. 2.2 According to the invention, the closing pin (30) has an outward-pointing cylindrical sub-portion (30a) and the discharge sleeve (20) has an inward-pointing cylindrical sub-portion (20a), the cylindrical sub-portions (20a, 30a) forming a transition fit or a tight clearance fit and a pressure-reducing and/or medium-flow-reducing working geometry (34) being provided in the cylindrical sub-portion (20a, 30a) of the closing pin (30) and/or of the discharge sleeve (20). 2.3 Use for mediums which are intended to be discharged with low pressure and without a pronounced spray jet.

Description

FIELD OF APPLICATION AND PRIOR ART

[0001] The invention relates to a discharger for a flowable medium, comprising a discharge sleeve, at whose one end there is provided a discharge opening for discharging the medium, and a closing pin, which is provided in the discharge sleeve and is longitudinally displaceable relative to the discharge sleeve and by which the discharge opening can be closed off.

[0002] Dischargers with designs of this type are known. One drawback with these is that a high medium pressure is generally present within the discharge sleeve before the closing pin opens up the discharge opening. Upon opening, this pressure results in a spray jet, which, according to the purpose of use, is meant to be prevented.

PROBLEMS AND SOLUTIONS

[0003] The object of the invention consists in refining the dischargers known from the prior art, particularly with regard to an improved spray pattern.

[0004] This object is achieved by a discharger of the generic type in which the closing pin has an outward-pointing cylindrical sub-portion and the discharge sleeve has an inward-pointing cylindrical sub-portion, the cylindrical sub-portions forming a transition fit or a tight clearance fit and a pressure-reducing and/or medium-flow-reducing working geometry being provided in the cylindrical sub-portion of the closing pin and/or of the discharge sleeve.

[0005] The working geometry is achieved, in particular, by a configuration having a small cross section through which the medium must flow. It thereby limits the fluid flow. This is particularly relevant in respect of mediums which are to be applied to an eye, since a strong spray jet caused by a large fluid flow is undesirable in this particular application. The working geometry which is provided according to the invention constitutes an advantageous and constructionally simple solution to the reduction of the fluid flow. This is advantageous, in particular, in dischargers whose discharge opening is opened in dependence on a medium pressure. It is particularly advantageous if the medium-flow-reducing geometry is adjoined by a diffuser in which the increased pressure is reduced again.

[0006] The configuration comprising cylindrical sub-portions means that the effect of the working geometry is not dependent on the relative position of the closing pin to the discharge sleeve, as would be the case, for example, with conical sub-portions whose spacing likewise changes as a result of an axial change of position.

[0007] In one refinement of the invention, the closing pin is longitudinally displaceable, in dependence on a fluid pressure of the medium, in a pumping chamber of a pumping device of the discharger and closes off the discharge opening if the fluid pressure of the medium is below a defined limit pressure. In this type of pressure-dependent closing pin control, the configuration according to the invention is particularly expedient, since the high pressure which is necessary for the relative displacement of the closing pin increases the risk of a problematic spray pattern.

[0008] In one refinement of the invention, the cylindrical sub-portion of the closing pin and/or of the discharge sleeve contains at least one medium duct. Such a medium duct constitutes a very simple form of a working geometry. The medium duct is preferably provided on the cylindrical sub-portion of the closing pin, since a removal from the mold during manufacture can then more easily be realized. In the simplest case, the medium duct extends axially parallel to the direction of displacement of the closing pin.

[0009] In a particularly preferred embodiment, the medium duct extends helically. Such an extent yields two advantages.

[0010] In the first place, a long medium duct is thereby attainable in spite of only short cylindrical sub-portions. In the second place, the medium duct having an outlet direction with a tangential component in combination with an adjoining chamber in front of the outlet opening acts at the same time as a diffuser, which latter reduces the pressure and velocity upon exit from the outlet opening.

[0011] In one preferred refinement of the invention, the closing pin is operatively connected to a pressure plate which can be actuated by the internal pressure, the closing pin preferably being configured in one piece with the pressure plate. Such a pressure plate allows the attainment of the intrinsically conflicting goals of the displacement of the closing pin at only low medium pressure, on the one hand, and the pressurization of the closing pin in the closing direction with a high spring force. As a result of its large surface area, the pressure plate leads to the opening force which opposes the spring force being achieved even by low pressure. This too helps to improve the medium discharge. For this purpose, the pressure plate surface area is preferably at least five times, preferably ten times larger, than the surface area of the discharge opening.

[0012] It is particularly preferred if the pressure plate consists at least partially of an elastic material, preferably of a material having an E-modulus below 1 kN/mm.sup.2, in particular having an E-modulus below 0.5 kN/mm.sup.2. The elasticity leads to transient pressure peaks of the medium pressure being absorbed by the pressure plate. This leads to improved opening characteristics of the discharge device. In particular, the combination of an inventive working geometry with an elastic pressure plate has proved very well-suited to ensuring an advantageous spray pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Further advantages and features of the invention emerge from the claims and the following description of a preferred illustrative embodiment of the invention, which is represented with reference to the drawings in which:

[0014] FIG. 1 and 2 show a discharge device according to the invention in a partially sectioned perspective representation and a partially sectioned side view, only that part of the discharge device which is relevant to the invention being represented.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0015] FIG. 1 and 2 show a portion 10 of a discharger according to the invention in a partially sectioned perspective representation and a partially sectioned side view.

[0016] The portion 10 comprises a discharge sleeve 20, which, in the represented embodiment, is configured in one piece with a housing (otherwise not represented) of the discharger, and a closing pin 30, which is disposed in the discharge sleeve 20 and the lower end of which is adjoined by an integrally attached pressure plate 40.

[0017] The discharge sleeve 20 has at its upper end a discharge opening 22, through which medium can escape when the discharger is used. In the non-actuated state of the discharger, this discharge opening 22 is closed off by a sealing portion 32 disposed at the upper end of the closing pin 30. The closing force is applied by a valve spring (not represented), which forces the unit comprising closing pin 30 and pressure plate 40 jointly upwards in the direction 2.

[0018] A discharge process is triggered by the pressure in an interspace 50 between the discharge sleeve 20 and the unit comprising closing pin 30 and pressure plate 40 being increased by means not represented in detail, in particular by a pump. This increased pressure acts upon the pressure plate 40 in a sub-region 50a, a slightly increased pressure, owing to the relatively large surface area of the pressure plate 40, producing a substantial opening force in a direction opposite to the direction 2. This opening pressure brings about a relative displacement of the closing pin 30 relative to the discharge sleeve 20 and thus an opening of the discharge opening 22.

[0019] In a region 60, the discharge sleeve 20 and the closing pin 30 have mutually matched cylindrical sub-portions 20a, 30a. The external diameter of the cylindrical sub-portion 30a of the closing pin 30 and the internal diameter of the cylindrical sub-portion 20a of the discharge sleeve 20 form a tight clearance fit. In the cylindrical sub-portion 30a of the closing pin 30 there is provided a helical 34 groove, which forms a duct 34 for the escaping medium. Owing to the tight clearance fit, the medium is able to make its way from the interspace 50 to the discharge opening 22 only through this groove 34.

[0020] When the discharger is actuated, the closing pin 30, in a manner not represented in detail in FIG. 1 and 2 and as a result of an increased fluid pressure of the medium, is displaced relative to the discharge sleeve 20 counter to the direction 2, so that the discharge opening 22 is opened up by sealing portion 32 at the upper end of the closing pin 30. The pressurized medium then makes its way through the groove 34 to the open discharge opening 22, the groove reducing the fluid flow of the medium in the style of a throttle valve. The fluid flow escapes at the upper end from the groove 34 into an interspace 52, which acts as a diffuser. In this interspace, the fluid pressure is decreased and the medium is released with reduced pressure through the discharge opening 22.

[0021] In a non-represented embodiment, the groove is provided in the cylindrical portion on the discharge sleeve instead of in the cylinder portion of the closing pin. Moreover, other configurations are also possible, in the simplest case, for example, grooves which are straight and orientated in the longitudinal direction of the closing pin.

Claims

1. Discharger for a flowable medium, comprising a discharge sleeve (20), at whose one end there is provided a discharge opening (22) for discharging the medium, and a closing pin (30), which is provided in the discharge sleeve (20) and is longitudinally displaceable relative to the discharge sleeve (20) and by which the discharge opening (22) can be closed off, characterized in that the closing pin (30) has an outward-pointing cylindrical sub-portion (30a) and the discharge sleeve (20) has an inward-pointing cylindrical sub-portion (20a), the cylindrical sub-portions (20a, 30a) forming a transition fit or a tight clearance fit and a pressure-reducing and/or medium-flow-reducing working geometry (34) being provided in the cylindrical sub-portion (20a, 30a) of the closing pin (30) and/or of the discharge sleeve (20).

2. Discharger according to claim 1, characterized in that the closing pin (30) is longitudinally displaceable, in dependence on a fluid pressure of the medium, in a pumping chamber of a pumping device of the discharger and closes off the discharge opening (22) if the fluid pressure of the medium is below a defined limit pressure.

3. Discharger according to claim 1, characterized in that the cylindrical sub-portion (20a, 30a) of the closing pin (30) and/or of the discharge sleeve (20) contains at least one medium duct (34).

4. Discharger according to claim 3, characterized in that the medium duct (34) extends helically.

5. Discharger according to claim 1, characterized in that the closing pin (30) is operatively connected to a pressure plate (40) which can be actuated by the internal pressure, the closing pin (30) preferably being configured in one piece with the pressure plate (40).

6. Discharger according to claim 5, characterized in that the pressure plate (40) a pressure plate surface area which is at least five times, preferably ten times larger, than the surface area of the discharge opening (22).

7. Discharger according to claim 5, characterized in that the pressure plate (40) consists at least partially of an elastic material, preferably having an E-modulus below 1 kN/mm.sup.2, in particular having an E-modulus below 0.5 kN/mm.sup.2.