Abstract:
A dynamic mixer configured to a double cartridge or a dispensing appliance, wherein the mixer includes two similarly configured inlets that are configured to connect to respective outlets of the double cartridge or the dispensing appliance, the outlets having either equal diameters wherein the inlets are inserted into the outlets of equal diameters, or the outlets have different diameters wherein one of the inlets fits over a smaller one of the outlets while another of the inlets fits into a larger one of the outlets. In another embodiment of the present invention, there is a dynamic mixer assembly including a dynamic mixer as just described, further attached to a double cartridge or a dispensing appliance.

Description:
This is a Continuation Application of U.S. patent application Ser. No. 09/716,323, now U.S. Pat. No. 6,443,612 B1, filed on Nov. 21, 2000, which claims priority from Switzerland Application Number 1999 2210/99, filed on Dec. 02, 1999 and from European Application Number 00810432.5 filed on May 18, 2000. The disclosures of the just mentioned applications and/or patents are incorporated by reference herein in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention refers to a dynamic mixer comprising a rotor housing in which a rotatable mixing rotor is arranged, said rotor housing being closed by a plate-shaped cover on the inlet side which is provided with inlets for the components to be mixed. 
     BACKGROUND OF THE INVENTION 
     A mixer of this kind is known from European Patent Application No. 0,492,412. An essential feature of this mixer is a plate-shaped connecting member comprising a wiper of a particular design on the mixing rotor. 
     SUMMARY OF THE INVENTION 
     On the background of this prior art, it is the object of the present invention to provide a dynamic mixer allowing to achieve an improved mixing quality as well as an increased mixing performance. This object is attained by a dynamic mixer wherein the mixing rotor comprises a rotor disk for the purpose of premixing said components, which is disposed near the inlets and whose surface is provided on the inlet side with means for carrying along the components to be mixed, said rotor disk comprising gaps allowing the passage of said components to the back side of said rotor disk and to the rotor hub, which are provided with mixing elements. 
     Preferred embodiments of the invention are defined in the dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail hereinafter with reference to drawings of exemplary embodiments, where 
         FIG. 1  shows a side elevation and partial section of a first embodiment of a mixing rotor of the invention; 
         FIG. 2  shows the mixing rotor of  FIG. 1  as seen from the inlet side; 
         FIG. 3  shows a cross-section of a second embodiment of a mixing rotor of the invention according to line III—III in  FIG. 4 ; 
         FIG. 3A  shows a cross-section according to line IIIA—IIIA in  FIG. 3 ; 
         FIG. 3B  shows a cross-section according to line IIIB—IIIB in  FIG. 3 ; 
         FIG. 4  shows the mixing rotor of  FIG. 3  as seen from the inlet side; 
         FIG. 5  shows the rotor housing of a mixer of the invention according to cross-section V—V in  FIG. 6 ; 
         FIG. 6  shows the rotor housing of  FIG. 5  as seen from the inlet side; 
         FIG. 7  shows the cover of the rotor housing of  FIGS. 5 and 6  according to section VII—VII in  FIG. 8 ; 
         FIG. 8  shows the rotor housing cover as seen from the outlet side; 
         FIG. 9  shows a longitudinal section of the assembled mixer of  FIGS. 3  to  8  connected to outlets of different diameters; and 
         FIG. 10  shows a longitudinal section of the assembled mixer of  FIGS. 3  to  8  connected to outlets of equal diameters. 
         FIG. 11  shows the dynamic mixer attached to an outlet end of a double cartridge or dispensing appliance with a screw nut. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The dynamic mixer of the invention is composed of a mixing rotor and a rotor housing comprising a rotor housing cover.  FIGS. 1 and 2  illustrate a first embodiment of a mixing rotor, and  FIGS. 3 and 4  show a second one. 
     Mixing rotor  1  of  FIGS. 1 and 2  essentially consists of a rotor hub  2  comprising a rotor disk  3  on the inlet side. The back side of the rotor disk is provided with mixing blades  4  which are followed by mixing projections  5 . According to  FIGS. 2 and 4 , on the inlet side, the rotor hub comprises a driver opening  6  for engagement with the driver of the mixer driving shaft which may have various shapes, e.g. rectangular, hexagonal, or cross-recessed. 
     On the inlet side, the rotor disk is provided with chamber partitions  7  which divide the rotor disk into chamber sections  8 . These sections serve for the metered, alternating and diametrically offset intake of the two components to be mixed and for their further transport. In order to prevent a stemming of the components, partitions  7  are shortened, i.e. they are not thoroughgoing. The rotor disk further comprises a collar  9  intended to cooperate with a sealing lip  34  attached to the rotor housing. Between the rotor housing and the circumference of the rotor disk, annular gaps  10  are created which are interrupted by partitions  7  and through which the components pass to the back side of the rotor disk and from there to the mixing elements in the cylindrical portion of the housing. 
     With reference to the second embodiment of a mixing rotor according to  FIGS. 3 and 4 , mixing rotor  11  with rotor hub  12  is provided with a rotor disk  13  on the inlet side. Mixing blades  4  as well as additional mixing blades  4 A are disposed on the back side of the rotor disk and followed by mixing projections  5 .  FIG. 3A  shows the cross-section of mixing projections  5  and  FIG. 3B  that of mixing blades  4 . 
     On the inlet side, rotor disk  13  is provided with carriers of alternating outward extension, i.e. carriers  15  project less to the periphery than carriers  14 . Carriers  14  and  15  have a tooth-shaped profile, and respective blades  15 Y or  15 Z provided on carrier  15  are staggered with respect to blades  14 Y or  14 Z on carrier  14 . 
     In this manner, the inlet side of the rotor disk is divided into partly open chamber sections  16  which serve for the metered, diametrically offset and alternating intake and for the further transport of the two components to be mixed, thus contributing to premixing. In this embodiment as well, the components coming from the inlets can only pass to the back side of the rotor disk through the annular gaps between the circumference of the rotor disk and the rotor housing. However, it is also possible to provide annular gaps which are closer to the center, either combined with the peripheral gaps or exclusively. Furthermore, the rotor disk comprises a collar  18  intended to cooperate with the above-mentioned sealing lip. 
     Mixing rotor  1  or  11  is disposed in a bipartite rotor housing as illustrated in  FIGS. 5  to  8 . Rotor housing  19  according to  FIGS. 5 and 6  comprises a plate-shaped housing portion  20  receiving rotor disk  13  and a cylindrical housing portion  21  receiving rotor hub  12 . The bottom surface of plate-shaped housing portion  20  comprises a first, outer stator comb composed of individual ridges  23 , the premixed components passing through the spaces  24  between the ridges to the second, inner stator comb  25  comprising inner ridges  26  with spaces  27  through which the premixed components pass to mixing blades  4 A,  4  and to mixing projections  5  in order to be divided and mixed once again. The plate-shaped housing portion further comprises a contact surface  28  for a bayonet ring  35 . 
       FIGS. 7 and 8  show a rotor housing cover  29  comprising a rotor bearing  30  receiving the carrier hub  31  and two similar inlets  32  and  33 . For a good sealing of the carrier hub, rotor housing cover  29  is provided with a sealing lip  34 .  13 . As can be seen from  FIGS. 7 and 8 , in an embodiment of the present invention, each of the two inlets  32 ,  33  comprises a cylindrical projection  400  having a first hollow portion  410 , the cylindrical projections  400  being attached to or formed into the cover  29  of the dynamic mixer. Still further, as can be seen from  FIGS. 7 and 8 , the cover may include second hollow portions  420  which are proximate to the first hollow portions  410 , the second hollow portions being angled with respect to the first hollow portions. Additionally, as can be seen from these figures, the hollow portions are configured to channel components to be mixed into the dynamic mixer, and the cross sections normal to the direction of channeling of the first hollow portions are substantially similar to the cross sections normal to the direction of channeling of the second hollow portions.  FIGS. 7-10  show that the area of the cross sections normal to the direction of channeling of the second hollow portions may be substantially equal to each other. 
     It is also possible to provide further stator elements on cylindrical housing portion  21  in the area of the crowns of mixing projections in order to obtain a further improved mixing quality. 
       FIGS. 9 and 10  illustrate that a suitably dimensioned mixer of the invention can be used both for double cartridges or dispensing appliances having outlets of equal diameters and for double cartridges or dispensing appliances having outlets of different diameters, even regardless of its orientation. 
       FIG. 9  shows a cross-section of an assembled mixer having equally dimensioned inlets, the mixer being connectable to a double cartridge or a dispensing appliance having containers of a cross-sectional ratio of 5:1 and outlets of different diameters. In  FIG. 9 , only outlets  37  and  38  are illustrated. One inlet  32  of the mixer fits over smaller outlet  37 , and the other inlet  33  of the mixer fits into larger outlet  38 , the mixer being attachable without a previous orientation. 
       FIG. 10  illustrates that the same mixer as in  FIG. 9  is also connectable to a double cartridge or a dispensing appliance having equal outlets, the two inlets  32 ,  33  of the mixer being insertable into outlets  39 ,  40 , again requiring no previous orientation. 
     The just described configurations of the inlets and outlets are particularly advantageous for a dynamic mixer. Specifically, the configurations allows the components to be mixed to form component streams which have the effect of enhancing the dynamic mixing effect. This is readily seen in the case of a double cartridge or a dispensing appliance having outlets of different diameters. When one of the inlets of the mixer is inside the larger outlet, as is seen in  FIG. 9 , the component stream is smaller and nearer in size to the material stream of the smaller outlet, thus providing better mixing results over a stream from a large outlet and a stream from a small outlet, where the size of the stream is determined solely by the size of the outlet. 
     In both embodiments, the mixer is secured by means of a bayonet ring  35  or alternatively an internally threaded screw nut  135 , as may be seen in FIG.  11 . The same mixer can also be used for double cartridges or dispensing appliances having cross-sectional and outlet diameter ratios other than 1:1 and 5:1, e.g. 10:1. 
     As compared to known dynamic mixers of the same construction length, the described arrangement allows a substantially increased mixing power and quality at lower speeds and operates with a relatively low back pressure. The invention is not limited to the illustrated shapes but different shapes of the chamber sections and of the stator combs, mixing ridges, or mixing projections are possible within the scope of the invention.