Abstract:
A two-piece dosing cap ( 10 ) comprised of a base part ( 2 ) and a closure part ( 3 ). Both parts ( 2  and  3 ) can be displaced in relation to one another in the axial direction by means of suitable threads ( 20, 30 ). Above a cylindrical part ( 22 ), the base part ( 2 ) has a head part ( 23 ) comprising an outer wall ( 24 ), which is closed on top by a top surface ( 25 ). A plurality of outlet orifices ( 21 ) is integrally formed in the outer wall ( 24 ). The closure part ( 3 ) includes a mirror-inverted truncated cone ( 33 ), the outer wall ( 34 ) of which is completely closed, and therefore rests in the closed state with the interior surface thereof on the exterior surface of the outer wall ( 24 ) of said base part ( 2 ). Both parts comprise sealing means which are matched to one another.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a plastic two-piece dosing cap for solid or flexible containers, particularly for the use on plastic collapsible bags, comprised of a base part, which can be mounted on the receptacle, and a closure part held thereon so as to be movable in a screw-like fashion, wherein the two parts can be displaced relative to one another in the axial direction and can be brought from a closed position to an open position and vice versa by the screw-like movement, wherein the base part has external thread and at least one outlet orifice arranged above the same, the closure part having on the other hand interior thread and a central outlet orifice, and wherein said base part comprises a cylindrical region having external thread and a head part having an external contour in the form of a truncated cone above of the latter. The head part has a conical outer wall, which has at least one outlet orifice and is closed by a top surface of said head part. The closure part on the other hand is configured as a mirror-inverted truncated cone above the interior thread thereof, which is positioned in a cylindrical section of said closure part. 
         [0002]    Dosing caps made from plastic having the construction, which is relative in this case, are known from prior art since the 1950&#39;s. The British patent publication GB-726756-A shows a typical example. This cap, which, for example, is suited to be placed on tubes, comprises a screw cap as the closure part, which has a conical outer wall, and a spring-loaded sealing peg is located inside of said closure part. The sealing peg is moved downwards when the internal pressure is raised and thereby unblocks the opening in said closure part. 
         [0003]    Whereas in the aforementioned solution, the closure part contributes a functional share to the dosed dispensing of fluids, the British patent publication GB-1399840 depicts a solution which is considerably more complex and is provided with an actual valve plate, wherein in this instance the closure part does not have any influence on the dosing action of the cap. Pursuant to the British patent publication 1187081-A, the closure part performs a closing and dosing function in the form of a screw cap. In this case, an orifice is eccentrically disposed in the top surface and said orifice is closed by the container neck or a base part, which in the closed position engages in said orifice. This solution is by design extremely simple, is, however, suited as a dosing cap only for dispensing small amounts. Typically such dosing caps are placed on containers for cosmetics. 
         [0004]    The majority of solutions, which apply in this case, usually comprise a closure part having an upper orifice positioned centrally in the top surface and a sealing peg, which is indirectly or directly connected to a base part, wherein these two parts can be moved upwards and downwards in relation to one another by a screw-like movement; thus enabling the fluid to flow around the sealing peg. The German patent publication DE 9204076 U depicts a typical example of such a solution. 
         [0005]    The German patent publication DE-A-2839284 is considered to be the most relative prior art. Said publication relates to a plastic two-piece dosing cap for solid and flexible containers, comprised of a base part which can be mounted on the receptacle and a closure part held thereon so as to be moved in a screw-like fashion, wherein the two parts can be displaced in relation to one another in the axial direction and can be brought from a closed position into an open position and vice versa. In so doing, the base part comprises exterior thread and at least one outlet orifice disposed above the same, the closure part on the other hand comprising interior thread and a central outlet orifice, wherein said base part has a cylindrical region with exterior thread and a part having an outside contour in the shape of a truncated cone, which is disposed above the latter. 
         [0006]    In principle, two-piece dosing caps of the above mentioned type have been known in similar design from prior art for quite some time. An example of these older caps is a tube cap pursuant to the German patent publication DE 636805. Caps based on the same principle, namely having a bottom part of truncated cone shape and a conical part which can be displaced in relation to the latter, have been known for a long time from prior art. Said caps, however, are conceived as tube caps and the base part is in this case virtually configured as a solid body. Even the proven, most relevant prior art comprises a bottom part, which is virtually manufactured from a solid body and the orifices are virtually configured as canals. A tube cap is also known from the German patent publication DE-A-1863157. In this case, however, instead of a truncated cone, two conical parts are aligned with one another. This arrangement of course allows for only a small outlet orifice and this opening has to be centrally disposed above the point of the lower cone, whereas in the bottom part, the orifices are formed in the conical wall. 
         [0007]    The present two-piece dosing cap according to the invention is however configured and designed for containers having large capacities and correspondingly larger quantities to be dosed. Considerably larger outlet orifices are thus closed. In such systems, bottom parts, which for all intents and purposes are designed from a solid body, are no longer ecologically and economically feasible. The material usage is thereby much too large. A suitable thin-walled solution to the bottom part as well as to the top part in order to thereby save material would seem logical to the specialist in the field. Such a solution, however, cannot be realized in an obvious way due to the forces which thereby arise. This results from the fact that a one to one implementation of the conventional solutions to date would lead to impermeability deficiencies, which would result from the thin-walled parts. 
       SUMMARY OF THE INVENTION 
       [0008]    It is therefore the aim of the present invention to improve a two-piece dosing cap of prior art mentioned above such that a large dosing cap can be produced in a thin-walled and thereby material saving manner and at the same time be capable of withstanding a correspondingly higher internal pressure. 
         [0009]    This aim is met by a two-piece plastic dosing cap of the kind mentioned at the beginning of the application. The base part is hereby to have a head part disposed above a cylindrical region having exterior thread, wherein the at least one outlet orifice is positioned in the conical outer wall and the top surface of the head part is closed. The closure part on the other hand is designed as a mirror-inverted truncated cone above the interior thread thereof, which is positioned in a cylindrical section of said part. In so doing, the top surface of the truncated cone is at least almost completely open; and in the closed state, the conical exterior surface of the outer wall of the base part and the conical interior surface of the closure part come to rest in a sealing manner one on top of the other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Additional advantageous embodiments of the subject matter of the invention are disclosed in the dependent claims and the effect and relevance of said embodiments are explained in the following description with reference to the accompanying drawings. The following are shown: 
           [0011]      FIG. 1  an exploded view of the dosing cap according to the invention in perspective depiction having the two main components, namely the base part and the closure part, arranged in alignment one above the other; 
           [0012]      FIG. 2  the same dosing cap as in  FIG. 1  in the assembled state in an open position, once again in perspective depiction, whereas 
           [0013]      FIG. 3  a vertical partial section shows again the same dosing cap in the closed state, and 
           [0014]      FIG. 4  the same view as pursuant to  FIG. 3 , wherein the dosing cap is depicted here in the open state. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    It can be clearly seen in  FIG. 1  that the dosing cap, which as a total entity is denoted by the reference number  1  and can be as such in  FIG. 2 , comprises two main components, namely the base part  2  and the closure part  3 . Said base part  2  allows for the direct mounting on a container, in the example depicted here for mounting on a plastic bag. For this purpose, the base part  2  has a circumferential, outwardly directed flange  26 , which is adjoined at the end thereof by a cylindrical region  22 . This cylindrical region  22  has exterior thread  20 . The cylindrical region  22  is in turn adjoined by a part, which as a total entity is designated as the head part  23 . Said head part  23  comprises a conical outer wall  24 . A top surface  25  closes said head part  23  from above. The top surface  25  is therefore completely closed. 
         [0016]    At least one outlet orifice  21  is formed in the conical outer wall  24 . A plurality of outlet orifices  21  are, however, preferably disposed in said outer wall. The outlet orifices  21  can be dimensioned here practically so large that only narrow webs remain between the individual outlet orifices  21 . In the preferred exemplary embodiment depicted here, three outlet orifices  21  are formed in the outer wall  24 , which in total make up about 50% of the surface area of said conical outer wall  24 . The outlet orifices  21  are likewise preferably configured height-wise such that they extend at least approximately over the entire height of said conical outer wall  24 . This embodiment is particularly suited to fluids, of which a large volume is to be dispensed each time. If the subject matter relates more to pourable products, as, for example, salt, the outlet orifices are to be dimensioned so large that practically only narrow webs remain between the individual outlet orifices. In so doing, practically no material can remain on the outer surface of the conical outer wall  24 , which has now been reduced to very few webs, when the dosing cap is closed. 
         [0017]    The conical outer wall  24  is adjoined from above, as previously mentioned, by the completely closed top surface  25 . Said top surface is preferably embodied having a material thickness such that the wall thickness of said top surface  25  is virtually twice as thick as the conical outer wall  24  of the head part  23 . A circumferential shoulder, which forms a ledge  28 , is formed in the edge area of said top surface  25 . The height of this ledge  28  corresponds approximately to the thickness of said conical outer wall  24  of the head part  23 . In addition, a circumferential sealing groove  29  is formed in the vertical section of the ledge  28 . This can be seen best in  FIG. 4 . 
         [0018]    The closure part, which has already been mentioned, can be screwed onto the base part  2 . Said closure part  3  is designed such that the interior surface thereof rests in the closed state against the exterior surface of the base part in a sealing manner. Said closure part  3  has accordingly likewise a cylindrical section  31 . The interior thread  30  of said closure part  3  is formed on the interior side of said cylindrical section  31 . Said interior thread can only be seen in the sectional drawings of  FIGS. 3 and 4 . The cylindrical section  31  of said closure part  3  is also adjoined here by a truncated cone  33 . The outer wall  34  of the truncated cone  33  is completely closed. In contrast, the top surface  32  of said truncated cone  33  is completely open except for an upper edge  35  and forms the outlet orifice  32 ′ of said closure part  3 . Said cylindrical section  31  has on the outer side thereof means  42  for increasing adhesion. These means can, for example, be configured as ribs running vertically or, as is depicted here, in the shape of a polygon, similar to a polygonal nut. 
         [0019]    Depending upon how high the cylindrical region  22  or the cylindrical section  31  of the closure part are configured, the greater is the relative, axial mobility of said closure part in relation to the base part  2  and the remaining clearance between the truncated cone  23  of the base part  2  and the truncated cone  33  of said closure part  3  is respectively correspondingly large. For the use of pourable products, said cylindrical region  22  or the cylindrical section  31  should preferably be configured longer than would be the case for a dosing cap suitable for fluids. 
         [0020]    The required impermeability for such a cap is of course correspondingly higher for applications using liquid media than for applications on receptacles, which contain pourable media. In  FIGS. 3 and 4 , a preferred embodiment of different sealing options for a dosing cap for liquid media is depicted. In principle, the sealing takes place as a result of the truncated cone  23  of the base part  2  engaging in a positive-locking manner in the outlet orifice  32 ′ of the top surface  32  of the closure part  3 . For this purpose, said base part  2  comprises, as already described, a circumferential shoulder  28  and the outer wall  34  of the truncated cone  33  of said closure part  3  is configured such that said outer wall  34  is bent towards the inside at the end thereof and thus forms the stated bend  36 . Said bend  36  comes to rest in a positive-locking manner in and on the shoulder  28 , which bounds the top surface  25  by projecting inwardly from the margins of the top surface  25 . In order to increase the impermeability, said bend  36  is preferably is provided with a sealing bead  37 , which is directed towards the center, at the end which extends vertically. This sealing bead basically relates to a short, inwardly directed lip having a thickness of only a few tenths of a millimeter. It is useful to introduce a sealing groove  29 , which matches the sealing bead  37  in a positively-locking manner, into the vertical section of the shoulder  28 . In the completely closed state, said sealing bead  37  thus engages in the corresponding sealing groove  29 . 
         [0021]    Provision is made here for a further sealing option by sealing beads  38  being integrally formed on the interior side of the conical outer wall  34 . These sealing beads  38  project vertically from said conical outer wall  34  and the extension thereof is matched to the form of the outlet orifices  21 . In the completely closed state of the dosing cap, said sealing beads  38  rest against the edges of the outlet orifices  21  in a sealing manner. As a result, a tactile engagement in the closing position arises because said sealing beads  38  already bear on the exterior surface of the conical outer wall  24  before reaching the end position and in the process practically clean said conical outer wall. The user consequently hears and feels if he completely closes the dosing cap, and in the same manner said user has to overcome an increased resistance before he can open said dosing cap. 
         [0022]    It is of course useful and particularly for the dosed dispensing of liquid media if the orifice region is bounded and the user cannot mistakenly screw the closure part completely off of the base part. In order to prevent this, a retaining collar  27  is integrally formed on the base part  2 . This retaining collar  27  runs below the exterior thread  20  of said base part  2 , i.e. practically in the region between the flange  26  and said exterior thread  20  in the cylindrical region  22 . Retaining hooks  39  are accordingly integrally formed on the closure part  3 , which catch when said closure part  3  is maximally screwed onto said retaining collar  27 . Said retaining hooks  39  can be directly molded on extensions or integrally formed on the bottom edge of the cylindrical section  31 . In the especially preferred embodiment depicted here, said retaining hooks  39  are molded on spring tongues  41 . These spring tongues  41  are molded into recesses  40  in the outer wall of the cylindrical section of said closure part  3 . This embodiment has two advantages, namely on the one hand that assembly is hereby facilitated and on the other hand said retaining hooks  39  prevent any damage being done to the threads during assembly. The threads thereby retain the sealing effect thereof. The spring tongues  41  are configured to be longer than the height of the cylindrical section  31  and therefore project downwards. This can, for example, be seen in  FIG. 2 , however, also in  FIGS. 3 and 4 . Such spring tongues  41  cannot be seen in  FIG. 1  because in this instance the retaining hook  39  is configured as a circumferential bead on the interior side of the cylindrical section  31  of said closure part  3 .