This invention relates to apparatus for mixing and dispensing multiple flowable components such as dual component adhesives.
Dual component adhesives are commonly dispensed from multi-chamber cartridges. Typically, one component is the adhesive in an unactivated form and the other component includes an activator (e.g. a catalyst) that activates curing of the adhesive. A static mixer coupled to an outlet of the cartridge mixes the components to activate curing of the adhesive as it is dispensed.
The two main types of cartridges are side-by-side and coaxial cartridges. Side-by-side cartridges have two storage cylinders adjacent each other in a parallel orientation. Coaxial cartridges have one storage cylinder located within another storage cylinder. Outlets for both types of cartridges may be configured in a side-by-side or coaxial manner. The present invention is directed to both side-by-side and coaxial cartridges with coaxial outlets, with one outlet located within the other outlet.
Coaxial outlets are typically circular in design which allows for use of many standard static mixers. The circular design makes the cartridge and static mixer easier to assemble because rotational orientation is not required. The design and assembly of closure plugs is also simpler because the parts are circular in shape and they do not require rotational orientation.
The following embodiments and aspects thereof are described and illustrated in conjunction with systems and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
One aspect provides an injector for a dispenser for multiple flowable components, the dispenser having a multi-chamber cartridge with a first outlet for a first flowable component arranged within a second outlet for a second flowable component. The injector includes an inner sleeve for fitting engagement with an inner wall of the first outlet of the dispenser, wherein an interior of the inner sleeve defines a first passage for the first flowable component; and an outer sleeve for fitting engagement with an outer wall of the first outlet of the dispenser. The outer sleeve and the inner sleeve are coupled. The inner sleeve and outer sleeve may be concentric and may be coupled at a distal shoulder of the injector. The distal end of the first passage may have a plurality of injector outlet holes. The injector outlet holes may be oriented radially outward. The injector outlet holes may be sized to restrict backflow. The injector outlet holes may have a diameter in the range of 0.005″ to 0.100″, or in the range of 0.010″ to 0.035″. The distal end of the first passage may be hemispherical. The injector may also have an inverted frustoconical element disposed distal of the injector outlet holes and proximal of a static mixer of the dispenser. The frustoconical element may be molded integrally with the injector, molded integrally with the static mixer, or provided as a separate piece from the injector and the static mixer. The proximal portion of the distal shoulder of the injector may be configured for mating engagement with a distal tip of the first outlet. An exterior of the outer sleeve partially may define a second passage for the second flowable component. The wall thicknesses of the inner sleeve and/or the outer sleeve may be sized to provide simultaneous flow of the first flowable component and the second flowable component through the first passage and the second passage respectively into a mixing chamber of the dispenser at a predetermined mixing ratio. The outer sleeve may include a plurality of radially arranged ridges, wherein spaces between the ridges partially define the second passage. An outer wall of the ridges may include a locking element for interlocking with a locking element on an inner wall of a mixer housing of the dispenser. A proximal end of the outer sleeve may include an outwardly radiating flange for abutment against an inner wall of the second outlet. The flange may include a plurality of cutouts. The inner sleeve may displace a sufficient volume of air within the first outlet to prevent overflow of the first flowable component from the first outlet when an extended-length storage plug is inserted into the first outlet. The injector may be for a handheld cartridge dispenser or a bulk material dispensing or meter-mix dispense (MMD) system.
Another aspect provides an injector for a dispenser for multiple flowable components, the dispenser having a multi-chamber cartridge with a first outlet for a first flowable component arranged within a second outlet for second flowable component. The injector includes an inner sleeve for fitting engagement with an inner wall of the first outlet of the dispenser, wherein an interior of the inner sleeve defines a first passage for a first flowable component. The distal end of the first passage may have a plurality of injector outlet holes. The injector outlet holes may be oriented radially outward. The injector outlet holes may be sized to restrict backflow. The injector outlet holes may have a diameter in the range of 0.005″ to 0.100″, or in the range of 0.010″ to 0.035″. The distal end of the first passage may be hemispherical. The injector may also have an inverted frustoconical element disposed distal of the injector outlet holes and proximal of a static mixer of the dispenser. The frustoconical element may be molded integrally with the injector, molded integrally with the static mixer, or provided as a separate piece from the injector and the static mixer. A distal portion of the injector may include a stop for engagement with a distal tip of the first outlet. A wall thickness of the inner sleeve may be sized to provide simultaneous flow of the first flowable component and the second flowable component into a mixing chamber of the dispenser at a predetermined mixing ratio. The inner sleeve may displace a sufficient volume of air within the first outlet to prevent overflow of the first flowable component from the first outlet when an extended-length storage plug is inserted into the first outlet. The injector may be for a handheld cartridge dispenser or a bulk material dispensing or meter-mix dispense (MMD) system.
Another aspect provides a mixing assembly including: a static mixer; and an injector as described above.
Another aspect provides a mixing assembly including: a static mixer; and an injector as described above wherein the static mixer and the injector are integrally formed.
Another aspect provides a dispenser including: a multi-chamber cartridge comprising a plurality of outlets; a static mixer; and an injector as described above. At least a portion of the injector and the plurality of outlets of the multi-chamber cartridge may be integrally formed.
In drawings which show non-limiting embodiments of the invention:
Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
The term “adhesive” as used in this specification includes adhesives, glues, sealants, caulks, reaction cured resins, and the like. The term “dispenser” as used in this specification includes handheld cartridge dispensers as well as bulk material dispensing or meter-mix dispense (MMD) systems such as drum or pail pump dispensers. The term “cartridge” as used in this specification includes handheld cartridges as well as cans, drums, pails, tote-bins, tanks and the like. The terms “proximal” and “distal” as used in this specification refer to positions relatively closer to and further from, respectively, the cartridge end of the dispenser. The terms “inner” and “outer” as used in this specification refer to positions relatively closer to and further from, respectively, the longitudinal axis of the cartridge outlet. The terms “inward”/“inwardly” and “outward”/“outwardly” as used in this specification refer to orientations toward and away, respectively, from the longitudinal axis of the cartridge outlet.
The present invention addresses at least some of the above problems.
Cartridge 12 includes a first storage chamber 18 and a second storage chambers 22. First storage chamber 18 has a first outlet 20 in coaxial arrangement with a second outlet 24 of second storage chamber 22. In the illustrated embodiment first storage chamber 18 stores a minor flow component (e.g. an activator) and second storage chamber 22 stores a major flow component (e.g. an unactivated adhesive). The major flow component is mixed with the minor flow component at some ratio greater than 1:1. In other embodiments the storage chambers may be the same size and the flow components may be mixed at a 1:1 ratio.
Injector 14 fits on to coaxial first and second outlets 20, 24 of cartridge 12. Injector 14 includes an inner sleeve 26 and an outer sleeve 28. Inner sleeve 26 fittingly engages inner wall 30 of first outlet 20. Inner sleeve 26 shields at least a portion of first outlet 20 from contact with flow components, keeping the interior of first outlet 20 clean for future applications. In some embodiments, the inner sleeve may extend up to or close to the proximal base of first outlet 20. Outer sleeve 28 has an inner wall 32 which fittingly engages outer wall 34 of first outlet 20. In other embodiments, the outer sleeve may be absent.
Inner sleeve 26 and outer sleeve 28 are concentric. Inner sleeve 26 and outer sleeve 28 connect at a distal shoulder 36 of injector 14. In other embodiments the cartridge outlets may be arranged one within another but not coaxially (i.e., the axes of the cartridge outlets may be offset); in such embodiments the inner and outer sleeves of the injector would be similarly offset to ensure proper engagement between the injector and cartridge outlets. A proximal portion of distal shoulder 36 matingly engages distal tip 40 of first outlet 20. In other embodiments the distal shoulder may not necessarily engage the distal tip of the first outlet.
In embodiments where the outer sleeve is absent, the distal portion of the inner sleeve may be provided with a stop having a proximal side for engagement with the distal tip of the first outlet to define the depth to which the injector inserts into the first outlet. Alternatively, friction fit between the outer wall of the inner sleeve and the interior of the first outlet may be sufficient to limit and define the extent to which the injector inserts into the first outlet.
In order to ensure a snug fit of the injector to the cartridge outlets, in some embodiments the injector may be provided with an inner sleeve and outer sleeve with a degree of resiliency and bias toward each other, i.e., the inner sleeve would be biased radially outwardly and the outer sleeve would be biased radially inwardly.
The displacement of spatial volume in first outlet 20 and second outlet 24 by injector 14 provides advantages. First, outer sleeve 28 displaces a volume of major flow component that would otherwise be present in the proximal, pre-mix region of second outlet 24 and mixer housing 66. The presence of outer sleeve 28 therefore reduces the wasted major flow component that would otherwise be left in second outlet 24 and mixer housing 66 after a final application.
Second, inner sleeve 26 displaces a volume of air that would otherwise be present in first outlet 20 during initial use or use after an extended-length storage plug is used during storage. Extended-length storage plugs extend the seal to the proximal base of first outlet 20 to increase the distance the minor flow component would have to migrate to evaporate and to separate the minor and major flow components to minimize the possibility of cross-contamination. During initial use or when an extended-length storage plug is removed at any other time, there is an air void in first outlet 20 that must be filled with the minor flow component as it flows to mixing chamber 44. Similarly there is an air void in second outlet 24 that must be filled with the major flow component as it flows to mixing chamber 44. The major flow component flows in greater volume and it typically reaches mixing chamber 44 in advance of the minor flow component; therefore the first mixtures dispensed from static mixers in known dispensers do not have adequate minor flow component to activate the adhesive. This initial mixture is therefore not usable. According to the invention, the presence of inner sleeve 26 in first outlet 20 displaces the air void that would otherwise need to be taken up by the minor flow component, and this in turn allows the minor and major flow components to reach mixing chamber 44 simultaneously to provide a proper initial mixture of the components. The wall thickness of inner sleeve 26 and/or outer sleeve 28 may be adjusted relative to the desired ratio of the two adhesive components to ensure simultaneous flow of the components into mixing chamber 44.
The third advantage provided is that inner sleeve 26 displaces a volume of minor flow component that would otherwise be left in first outlet 20 after an application. In the absence of the inner sleeve such as in known dispensers, that volume of minor flow component would, upon insertion of an extended-length storage plug, overflow into the mixing chamber and the second outlet. Cross-contamination with the major flow component in the second outlet would cause hardening of the components in the second outlet, rendering the cartridge useless. The presence of inner sleeve 26 avoids this problem by displacing the volume of minor flow component that would otherwise overflow.
The interior of inner sleeve 26 defines a flow passage 42 for the minor flow component to flow from first storage chamber 18 and first outlet 20 to mixing chamber 44. Flow passage 42 tapers from a wider diameter to a narrower diameter toward the distal direction. In other embodiments, the flow passage may not taper. The distal end 46 of flow passage 42 includes two opposing injector outlet holes 48 radiating outward to mixing chamber 44. Distal end 46 may be hemispherical to facilitate flow of the minor flow component out of injector outlet holes 48.
The injector outlet holes in the illustrated embodiment are circular but in other embodiments may be any other suitable shape. Also in other embodiments, one, or more than two, injector outlet holes may be provided. In yet other embodiments, the injector outlet holes may be absent and the flow passage may directly connect to the mixing chamber. Mixing of the two components is improved by splitting the flow of the minor flow component into multiple streams and directing the streams toward the outer regions of mixing chamber 44 where mixing action (i.e., shear force) during an application is the greatest. Improved mixing allows for reduction of one or more of the mixing elements 50 in static mixer 16, which in turn results in reduced back pressure or pressure drop to minimize backflow of the components.
Injector outlet holes 48 are sized as small as possible to allow flow of low viscosity minor flow component into mixing chamber 44 but at the same time limit backflow of high viscosity major flow component, or mixed components, back into flow passage 42. The diameter of injector outlet holes 48 depends on the size of the cartridge. For standard handheld cartridge sizes of 50 mL to 1000 mL, the range of diameters may be about 0.005″ to 0.100″, and preferably from about 0.010″ to 0.035″.
Mixer elements 50 and dispenser outlet 17 are designed to maintain a low back pressure so that residual pressure in dispenser 10 (between applications) is released out of dispenser outlet 17 and internal pressure is reduced, minimizing the force causing backflow into flow passage 42. For example, in some embodiments dispenser outlet 17 may be provided as large as practical (while accommodating the required flow fate and the viscosity of the mixed components), and injector outlet holes 48 may be provided as small as practical (while accommodating the required flow rate and viscosity of the minor flow component).
Injector 14 also includes a flange 56 at the proximal end of outer sleeve 28. In other embodiments, the flange may be absent. The outer edge 57 of flange 56 may abut against the inner wall 58 of second outlet 24. Flange 56 has one or more cutouts 60 to allow the major flow component to flow therethrough. In other embodiments, the flange may have holes or be otherwise perforated. Flange 56 aids in cleaning out second outlet 24 when injector 14 is removed from cartridge 12. In particular, as injector 14 is twisted and removed, flange 56 pulls both soft and hardened components out of second outlet 24.
Injector 14 further includes longitudinal ridges 62 radiating outward from outer sleeve 28 and extending from flange 56 (or the proximal end of injector 14) in a distal direction. In other embodiments the ridges may be absent. The spaces between ridges 62 and flange cutouts 60, bordered by ridges 62, the outer wall 64 of outer sleeve 28, inner wall 58 of second outlet 24, and the inner wall 68 of mixer housing 66, define a flow passage for the major flow component.
In some embodiments, ridges 62, and outer wall 64 of outer sleeve 28 may be provided with a textured surface that provides better bonding with hardened components. The textured surface enhances removal of hardened components from second outlet 24 as injector 14 and static mixer 16 are removed.
The invention accordingly guides the flow of components and reduces, if not eliminates, cross-contamination between the components and their vapors. For example, in order for any vapor cross-contamination to occur where injector 14 is fitted, vapors would have to either flow through small injector outlet holes 48 or permeate through three layers of solid material, namely outer sleeve 28, first outlet 20, and inner sleeve 26. In embodiments of the invention wherein the outer sleeve is absent, vapors would still have to permeate through two layers of solid material, namely the first outlet and the inner sleeve, to cross-contaminate. If any hardening of the components occurs due to any such cross-contamination, the hardened material would be removed in as described above when injector 14 and static mixer 16 are removed, thereby preventing blockage within cartridge 12.
Also shown in the embodiment in
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA2011/000480 | 4/21/2011 | WO | 00 | 11/16/2012 |
Number | Date | Country | |
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61328742 | Apr 2010 | US |