Abstract:
A static mixer apparatus providing a mixer and releasably affixed dispensing accessory in which the static mixer outlet tip has a dispensing accessory mounting structure to maintain orientation of the accessory about an axis defined by the structure, the structure having a generally cylindrical accessory mounting boss coaxial with the axis and defining a dispensing outlet for mixed material from the mixer and a projection extends radially from said boss for engagement with a cooperating feature of the dispensing accessory to determine and maintain at least one desired orientation of that dispensing accessory relative to the structure about the axis. The dispensing accessory is preferably asymmetric.

Description:
RELATED APPLICATION 
     This is a continuation-in-part of U.S. application Ser. No. 09/371,623 filed Aug. 11, 1999 now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The invention pertains to a nozzle of a static mixer that is configured to removably receive an attachment accessory thereon, particularly, in a desired fixed orientation. 
     BACKGROUND OF THE INVENTION 
     Static mixers for dispensing fluids such as adhesives, sealants, caulks, etc., from a multi-component dispenser often require the attachment of nozzle accessories, for example, shaped dispensers, extensions, hoses etc. These accessories are typically attached to the outlet tip of a static mixer with either an externally threaded mount which is integral with the outlet tip or by snap fitting or frictional engagement arrangements with a retaining shoulder as is well known in the art. 
     Existing snap on and thread on accessories are both deficient in one manner or another. Snap on accessories can be rotated to any position but have no means to retain them in any one position. Thread on accessories become secure in only one position. There is a need for a nozzle which can securely retain an attachment or accessory in a desired orientation and maintain the attachment in the desired alignment. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a outlet tip for a static mixer that is configured to secure accessories and prevent rotation or provide a desired amount of resistance to rotation in a manner such that the accessories are easily attached and detached from the nozzle and while ensuring that such attachments or accessories maintain a desired orientation with respect to the axis of the static mixer. 
     The desired amount of resistance to rotation depends on the type of accessory. While many variations in geometry can be designed for either of the two mating surfaces, it is in general best to keep constant the geometry of the common component, i.e. static mixer nozzle, and to vary the geometry of the accessory. For example, when an elbow or other highly asymmetrical part is to be mounted on an outlet tip, both parts must be of a highly interlocking design and provide a maximum resistance to rotation. Form tips such as a narrow fan need only a small amount of resistance to rotation. This is best accomplished by using less depth in the anti-rotation feature of the accessory while the outlet tip geometry remains consistent with a maximum depth of such an anti-rotation feature. 
     According to the invention there is provided a static mixer apparatus comprising a static mixer, having a static mixer element housed in an elongate tubular member terminated at an outlet tip by a dispensing assembly accessory mounting structure fast with the member, and an asymmetric dispensing accessory releasably affixed to said structure with a desired maintainable accessory orientation about an axis defined by the structure, the structure further comprising a generally cylindrical accessory mounting boss coaxial with said axis and defining the outlet tip having an outlet for mixed material from the mixer; a projection extending radially from said boss for engagement with a cooperating feature of said dispensing accessory to determine and maintain at least one said desired orientation of that accessory, relative to said structure, about said axis. 
     Also according to the invention there is provided a static mixer apparatus comprising a static mixer, having a static mixer element housed in an elongate tubular member terminated at an outlet tip by a dispensing assembly accessory mounting structure fast with the member, and an angled nozzle extension releasably affixed to said structure with a desired maintainable nozzle extension orientation about an axis defined by the mounting structure; (a) the mounting structure comprising a generally cylindrical extension mounting boss coaxial with said axis and defining the outlet tip having an outlet for mixed material from the mixer; and a projection extending radially from said boss for engagement with a cooperating feature of said nozzle extension to determine and maintain at least one desired orientation of that nozzle extension, relative to said structure, about said axis; and (b) the angled nozzle extension comprising a further nozzle accessory mounting structure, defining an outlet axis intersecting said axis defined by the structure, for releasably affixing a dispensing accessory to the extension with a desired maintainable orientation about said outlet axis, the further mounting structure comprising: a generally cylindrical extension mounting boss coaxial with said outlet axis and defining a dispensing outlet for mixed material from the mixer; and a projection extending radially from said extension boss for engagement with a cooperating feature of a said dispensing accessory to determine and maintain at least one desired orientation of that accessory, relative to said further structure, about said outlet axis. 
     Further according to the invention there is provided a static mixer apparatus comprising a static mixer, having a static mixer element housed in an elongate tubular member terminated at an outlet tip by a dispensing assembly accessory mounting structure fast with the member, an angled nozzle extension, and a dispensing accessory, the angled nozzle extension being releasably affixed to said structure with a desired maintainable nozzle extension orientation about an axis defined by the mounting structure; (a) the mounting structure comprising a generally cylindrical extension mounting boss coaxial with said axis and defining the outlet tip having an outlet for mixed material from the mixer; and a projection extending radially from said boss for engagement with a cooperating feature of said nozzle extension to determine and maintain at least one desired orientation of that nozzle extension, relative to said structure, about said axis; (b) the nozzle extension comprising a further nozzle accessory mounting structure, defining an outlet axis intersecting said axis defined by the structure, for releasably affixing a dispensing accessory to the extension with a desired maintainable orientation about said outlet axis, the further mounting structure comprising a generally cylindrical extension mounting boss coaxial with said outlet axis and defining a dispensing outlet for mixed material from the mixer; and a projection extending radially from said extension boss for engagement with a cooperating feature of a said dispensing accessory to determine and maintain at least one desired orientation of that accessory, relative to said further structure, about said outlet axis; and (c) the dispensing accessory comprising a dispensing accessory affixing structure, defining an inlet axis coaxial with the nozzle extension outlet axis when the dispensing accessory is releasably affixed thereto, the affixing structure comprising at least one further projection defining the cooperating feature, said further projection extending radially from said affixing structure to engage the projection of the nozzle extension to maintain at least one said desired orientation of the dispensing assembly about the outlet axis of the dispensing accessory. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a diagrammatic exploded perspective view of a double cartridge and static mixer as known in the art; 
     FIG. 2 is a fragmentary cross-sectional side view of the outlet tip of the present invention; 
     FIGS. 3 a  and  3   b  are a diagrammatic perspective view of the outlet tip and a separate dispensing accessory, respectively; 
     FIG. 3 c  is a fragmentary view of the accessory when mounted on the tip; 
     FIG. 4 is a fragmentary cross sectional view of interlocking protrusions of polygonal engaging surfaces extending from the surfaces of the outlet tip and dispensing accessory respectively, designed to provide a maximum amount of resistance to rotation; 
     FIG. 5 is a fragmentary cross-sectional view of a yet further view of interlocking protrusions with engaging surfaces designed to provide limited interference with relative rotation of an outlet tip and dispensing accessory; 
     FIG. 6 is a diagrammatic perspective view of an angled nozzle extension; 
     FIG. 7 is a fragmentary cross-sectional view of an asymmetric dispensing accessory; and 
     FIG. 8 is an end view of an asymmetric dispensing accessory. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring firstly to the prior art as illustrated in FIG.  1  and part of FIG. 2, a double cartridge  2  comprises two parallel cylindrical containers  4  each housing one of two flowable components to be mixed when desired in a static mixer  6  which terminates in an outlet tip  8  from which the components mixed by the static mixer  6  are expelled. The static mixer  6  may be separable from and attached to the containers  4  in a manner known per se. The containers  4  which are usually of a plastics material are joined by a bridge  10  defining a tubular outlet  12  in which the two components are separated by an internal dividing wall  13  to maintain the components separate and unmixed until they reach inlet  14  of the static mixer  6  for mixing therein. In a conventional manner, the static mixer, again usually of a plastics material, comprises a static mixer element  16  housed in an elongate tubular member  18  extending from attachment to the tubular outlet  12  to outlet tip  8 . Also in conventionable fashion the static mixer element comprises an axially extending serial plurality of alternating oppositely oriented helically twisted mixer blades which act in concert to efficiently and thoroughly mix the separate components as they flow through the static mixer  6  from the tubular outlet  12  to the outlet tip  8 . 
     As is also well known in this technology, pistons  20  are operated simultaneously by a suitable mechanism (not shown) with the cartridge being retained by the back plate  22 , to dispense the components simultaneously from the containers through the tubular outlet and static mixer to the outlet tip  8 . 
     Referring now to the present invention as illustrated in FIGS. 2,  3   a ,  3   b ,  3   c , and  4 , the outlet tip  8  of the static mixer  6  has an external multi-tiered profile through which extends a longitudinal axis  24  which is coaxial with the static mixer and a dispensing outlet  26  from which the components mixed by the static mixer  6  are dispensed through a dispensing accessory  28  shaped and designed for the application involved and attached, during use, to the outlet tip  8 . The dispensing accessory  28  is sized and shaped to cooperate with the outlet tip  8  for resilient support thereon in a sufficiently tight and sealed matter to prevent mixed components from leaking past the attachment arrangements. Such leakage may be prevented by a sufficiently tight connection between the outlet tip and the dispensing accessory and/or by the provision of suitable sealing means (not shown), as will be readily apparent to those skilled in the art. Resilient attachment of the dispensing accessory  28  on the outlet tip  8  is achieved by engagement of a circumferential band  30 , on a cylindrical interior surface of the dispensing accessory  28 , sized to engage resiliently a circumferential groove  32  formed on a cooperating outer cylindrical surface of the outlet tip  8 . The resilient engagement of the band  30  and groove  32  is facilitated by the inherent resilience of the plastics material from which the outlet tip  8  and the dispensing accessory are constructed although, in fact, only one of these components needs to be resiliently deformable for the resilient connections to be made. A frusto-conical surface  34  leading to the aforementioned cylindrical surface on the outlet tip  8  facilitates alignment of the dispensing accessory  28  with the outlet tip  8  and subsequent engagement of the band  30  with the groove  32 . The band  30  and groove  32  are shaped to facilitate not only engagement of the dispensing accessory  28  with the outlet tip  8 , but also to allow separation of these components when desired. 
     The cylindrical surface of the outlet tip is coaxial with the axis  24  and carries, fast therewith, and adjacent the groove  32 , at least one rib or spline  36  extending parallel to the axis  24 . As used herein, the terms rib and spline are to be considered to be interchangeable. Preferably, as shown in FIG. 3 a  and FIG. 4, there are a plurality of the ribs  36  spaced about the circumference of the aforementioned cylindrical surface of the outlet tip  8 . 
     The interior of the dispensing accessory  28  defines at least one, preferably a plurality of ribs  38 , extending parallel to the axis  24  when the dispensing accessory  28  is engaged on the outlet tip  8 . At least one of the dispensing accessory  28  and outlet tip  8  have a plurality of the ribs evenly spaced with a circumferential pitch to engage the ribs of the other dispensing accessory  28  and outlet tip  8 , to fixedly determine the orientation of the dispensing accessory  28  about the axis  24  when the dispensing accessory  28  engages the outlet tip  8  with the band  30  and groove  32  and the ribs of these components engaged. Of course, the band  30  and groove  32  are disposed when engaged, to ensure that simultaneously, the ribs of the dispensing accessory  28  and outlet tip  8  are also engaged. Typically the ribs  38  of the dispensing accessory are evenly spaced about the entire interior surface of the dispensing accessory while a plurality of ribs  36  are disposed on the cylindrical exterior surface of the outlet tip  8  with a pitch which is equal to or a multiple of the pitch of the ribs  38  of the dispensing  28 . It should be appreciated that while the current design of outlet tip has eighteen ribs  36 , as few as one rib  36  may be desirable for some applications. In any event, the ribs  36  and  38  are designed to engage one another to fixedly determine the orientation of the dispensing accessory  28  about the axis  24  relative to the outlet tip  8  in any one of a plurality of predetermined desired orientations. The fragmentary cross-section illustrated in FIG. 4 illustrates an engagement arrangement of ribs  36  and  38  which is based on interengaging polygons with pitches and dimensions to engage ribs  36  evenly spaced about the exterior of the outlet tip  8  and the entire inner periphery of the dispensing accessory  28 . 
     As shown in FIG. 4, the inner polygon of the dispensing accessory  28  can be formed to substantially match the polygon ribs  36  of the outlet tip The polygons may be of disproportionate shape and size (FIG. 5) so as to enable the dispensing accessory to have a limited rotation or slip feature such that a greater or lesser amount of interference created between the ribs  36 ,  38  provide a desired amount of resistance to rotation. For instance, polygonal interfering surfaces and the associated ribs which are substantially similar in size and shape tend to provide a greater resistance to slip and/or rotation, whereas polygonal interfering surface which are substantially dissimilar in size allow a desired amount of slippage between the surfaces. 
     Turning now to FIG. 6, an angled nozzle extension or angled intermediate accessory  42 , useful for directing flow from the outlet tip  8  in a particular desired direction, is shown. The angled nozzle extension  42  includes a first end  44  defined about the axis  24  and a second end  46  defining an axis  50  intersecting the first axis  24 . An interior circumferential surface of the first end  44  defines at least one and preferably a plurality of ribs  48  which extend parallel to the original axis  24  of the outlet tip  8  and are designed to lockably engage the ribs  36  of the outlet tip  8 . The ribs  36 ,  38 ,  48 ,  52  can be shaped differently and varied in number to effect a greater or lesser amount of resistance to rotation. 
     A central section  49  interconnects the first end  44  and the second end  46 . The second end  46  also includes at least one and preferably a plurality of engaging ribs  52  positioned parallel to axis  50 , and formed externally around an outer circumferential portion of the second end  46 . The ribs  52  are designed to fixedly engage the interior ribs  38  of the dispensing accessory  28  or another angled nozzle extension. The central section  49  of the angled nozzle extension  42  can include a supporting finger grip  54  adding further support for installing same on the static mixer outlet tip and additional integrity to the central section  49 . 
     The first end  44  further includes a circumferential band  56  located adjacent to the ribs sized to resiliently engage the circumferential groove  32  of the static mixer outlet tip  8 . Similarly, the second end is formed with a circumferential groove  58 , formed to resiliently accept a resilient engagement band  30  of a dispensing accessory or another angled nozzle extension. 
     While the orienting elements of the outlet tip  8  and dispensing accessory  28  have been described as ribs or splines, it will be appreciated that one of these could be in the form of hemispherical, pyramidal, circular or other cross-section projecting buttons to achieve the same result. 
     FIGS. 7 and 8 refer to an asymmetric dispensing accessory  60  which can be releasably attached to the static mixer  6  and is shaped to cooperate with the outlet tip  8 , using ribs  38 , and circumferential band  30  similar to dispensing accessory  28 . The angle X of asymmetric dispensing accessory  60  can be varied between about zero to about 90 degrees. Angle X permits the static mixer  6  to be positioned in an orientation approximately parallel to the work surface the dispensed fluid is being applied to. Asymmetric dispensing accessory  60  is shown with a wide dispensing opening  62 . Opening  62  may also be provided in alternate shapes conducive to applying dispensed fluid in thin, flat shape, to a round bead, or in droplet shapes. 
     REFERENCE NUMERALS 
       2  double cartridge 
       4  containers 
       6  static mixer 
       8  outlet tip 
       10  molded bridge 
       12  tubular outlet 
       13  dividing wall 
       14  inlet to static mixer 
       16  mixer element 
       18  elongate tubular member 
       20  pistons 
       22  back plate 
       24  longitudinal axis 
       26  dispensing outlet 
       28  dispensing accessory 
       30  circumferential band 
       32  circumferential groove 
       34  frusto-conical surface 
       36  ribs 
       38  ribs 
       42  intermediate attachment 
       44  first end 
       46  second end 
       48  ribs 
       49  central section 
       50  axis of second end 
       52  ribs 
       54  grip 
       56  circumferential band 
       58  circumferential groove 
       60  asymmetric dispensing accessory 
       62  dispensing opening 
     X angle