Patent Application
20160016195
The present application claims priority to GB Application No. 1412530.6 filed Jul. 15, 2014, which is hereby incorporated herein in its entirety by reference.
The present invention relates to an electrically powered dispenser for dispensing a mixture of viscous materials, for example for dispensing a two-component adhesive or sealant.
Known electrically powered multicomponent dispensers use a so called passive mixer attachment to mix the separately held components during the dispensing process. A passive mixer mixes the component as they flow through the mixer attachment, for example by the provision of material interleaving vanes, without dynamically driven components inside the mixer attachment. Passive mixers have the advantage of simplicity due to the absence of driven components and movable parts but, in particular where mixing ratios are high, such as 10:1 or larger, a long mixing flow path, and hence a long mixer attachment is required. Dynamic mixers have dynamically driven components inside the mixer attachment which actively interleave the materials as they flow through the mixer attachment. Advantageously, the increased mixing due to the active interleaving enables the length of the mixer attachment to be reduced. However, this comes at a price of added complexity as provisions have to be made for driving the components of the mixer attachment.
It is desirable to provide an electrically powered mixer/dispenser for dispensing and mixing viscous materials that combines the advantages of known electrically powered multicomponent dispensers with dynamic mixing in an efficient manner.
Aspects of the invention are set out in the independent claims. A dispenser for dispensing a mixture of viscous materials is provided, which has separate respective electric motors which drive a dispensing mechanism for dispensing the materials and a mixing mechanism for driving a dynamic mixer attachment. Advantageously, providing separate motors for each task provides a simple construction of the dispenser as each motor can be located close to the respective driven mechanism and can be controlled independently.
In some embodiments, the mixer attachment is a disposable dynamic mixer attachment. Examples of such disposable mixers are well known in the art.
The dispenser defines a handle portion to enable a user to hold the dispenser by gripping the handle in order to operate the dispenser as a handheld dispenser. The handle may be defined by a stock portion, which also houses the electric motor driving the dispensing mechanism.
In some embodiments, the motor driving the mixing mechanism may be secured, housed or disposed at a front end of the dispenser, adjacent where the mixer attachment is attached to the dispenser.
In some embodiments, the material to be dispensed is held relative to the dispensing mechanism by respective barrels that are part of the dispenser. At one end, the barrels are configured so as to enable the dispensing mechanism to engage the material and at the other end they are sealed by a mixer holder that provides a conduit from each barrel to an inlet of the mixer attachment. Such a dispenser can accommodate a foil pack (“sausage pack”) or bulk material, with a plunger of the dispensing mechanism directly engaging the foil pack or bulk material. In other embodiments, the dispenser is arranged to accept a cartridge providing the material holding barrels and a plunger of the dispensing mechanism is arranged to engage a piston inside the cartridge barrels to dispense the materials, with the mixer holder ensuring a sealing engagement between inlet ports of the mixer attachment and corresponding outlet ports of the cartridge.
In some embodiments, the dispenser comprises a controller arranged to control the operation of the respective motors to control dispensing and mixing. For example, in some embodiments, a dispensing action is controlled by a trigger provided on the dispenser. Actuation by a user of the trigger results in material being dispensed and mixed. Specifically, in some embodiments, the motor actuating the dispensing mechanism is controlled as a variable speed motor, with the degree of actuation of the trigger controlling the speed of operation of the motor and thus the dispensing speed. In some embodiments, the motor actuating the mixing mechanism is controlled as a fixed speed motor, operating the mixing mechanism at a fixed speed as soon as the trigger is actuated. In some embodiments, the motor actuating the dispensing mechanism is a variable speed motor and the motor actuating the mixer mechanism is a fixed speed motor.
A specific embodiment is now described by way of example only and with reference to the accompanying drawings, in which:
With reference to
A coupling plate 28 seals the barrels 14 at a front end of the dispenser and provides a fluidic path from the inside of the sealed barrels 14 to a mixer attachment 30, as will be described in detail below. A further motor 32 is housed by the holder portion 6, disposed at the front end of the holder portion 6, for driving a mixer mechanism that is coupled to the mixer attachment when the mixer attachment is in place.
With reference to
The coupling plate 28 is removably held against a sealing surface 46 of the motor mounting block 34 by four clamping toggles 48, which can engage respective recesses 50 to securely hold the coupling plate 28 against the motor mounting block 34 while sealing against the sealing surface 46. In the sealed configuration, the coupling plate 28 provides a conduit 52 for guiding flow from an outlet opening 54 of the barrel to a corresponding outlet opening 56 in the coupling plate. It will be understood that one conduit 52 and outlet 56 is provided for each barrel 14 and barrel outlet 54, that is two in the case described with reference to
With reference to
Returning to
The dispenser 2 comprises a controller (not shown) for controlling the operation of the motors 10 and 32 in response to actuation of triggers 24 and 26 by a user. Trigger 24 is coupled to a potentiometer, so that actuation of the trigger 24 generates a command signal related to the degree to which the trigger 24 is depressed. In response to this control signal, the controller controls the motor 10 to turn with a variable speed as a function of the control signal, so that the dispensing speed of the dispenser 2 can be controlled by a degree to which the trigger 24 is depressed. The controller also controls the motor 32 in response to depression of the trigger 24. In contrast to the motor 10, the motor 32 is not controlled to rotate at a velocity corresponding to the degree of depression of the trigger 24 but rather is simply turned on to mix dispensed material when the trigger 24 is started to be depressed and turned off when the trigger 24 is not pressed anymore to mix any dispensed material. Control of the motor 32 may be a simple on off switch, or the motor may be controlled to rotate at a fixed speed and/or generating a fixed torque, or simply be controlled by supply with a fixed current voltage.
In operation, each of the barrels 14 is loaded with a respective material in a foil pack and the coupling plate 28 is secured to the motor mounting block 34 by means of the clamping toggles 48. Typically, the materials will form a two (or more) component adhesive or sealant when dispensed and mixed together. A mixer attachment 30 is attached to the coupling plate 28 and held in place by means of the mixer retainer plate 72 being engaged. To dispense and mix the materials, the user depresses the trigger 24 to a desired degree and for a desired amount of time to dispense a desired amount of materials at a desired speed. Actuation of the trigger causes the motor 10 to drive the plunger 16 into the barrels 14, resulting in a dispensing pressure which causes flow of the materials through the respective conduits 52 into the mixer housing 60 where they are mixed by rotation of the mixer components 66 rotating inside the mixer housing 60. When it is desired to retract the plungers, for example to change the foil packs inside the barrels 14, a user depresses the trigger 26 until reverse rotation of the motor has caused the plungers 16 to retract sufficiently.
While a specific example of an embodiment has been described, it will be appreciated that many operations, alterations and juxtapositions of the features described above are possible and will readily be apparent to the person skilled in the art and that, accordingly, the above description is made by way of example and not limitation.
For example, the described embodiment can readily be adapted to other number of materials to be mixed, for example three or four. Further, while an embodiment with sealed barrels and materials in respective foil packs has been described above, it will be appreciated that the sealed barrels as material holders can be replaced with a holder for a cartridge combining two or more barrels holding respective materials and providing respective outlets for engagement with the mixer attachment.
Various constructional details can also be varied. For example, other securing arrangements than the clamping toggle described above are equally possible, for example sliding arrangements or arrangements in which the coupling plate is held in place by threaded nuts. It will also be appreciated that the configuration of the drive dog and mating recess can be inversed so that the recess is provided on the mixer attachment 30 and the drive dog on the drive shaft 42. Evidently, other arrangements for coupling the drive shaft to the mixer attachment are equally possible.
Regarding the control of the two separate motors discussed above, it is equally envisaged that both motors could be operated with variable speed or with a fixed speed. Equally either or both motors may be operated using a different control scheme, for example one or both could be operated with fixed current, or variable flux, voltage or torque control, as appropriate. Thus, any combination of the same or different control schemes for the two motors is possible, subject to the application constraints.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1412530.6 | Jul 2014 | GB | national |
