Foam dispensing systems with multiple liquid supplies, and related refill units

An exemplary foam dispenser includes a housing, a plate located in the housing, a first dispensing wheel located proximate the plate. The first dispensing wheel has a plurality of pinch members and is rotatable about an axis. The exemplary dispenser includes a second dispensing wheel located proximate the plate. The second dispensing wheel having a plurality of pinch members and rotatable about the same axis as the first dispensing wheel. Rotation of the first dispensing wheel is configured to pinch a first flexible tube against the plate and to move a first liquid through the first tube; and rotation of the second dispensing wheel is configured to pinch a second flexible tube against the plate and to move a second liquid through the first tube. The exemplary dispenser includes a motor for rotating the first and second dispensing wheels and a motor controller for starting and stopping the motor.

TECHNICAL FIELD

The present invention relates generally to foam dispensing systems having multiple liquid supplies, and refill units for such dispensing systems.

BACKGROUND OF THE INVENTION

Liquid dispensing systems, such as liquid soap and sanitizer dispensers, provide a user with a predetermined amount of liquid upon actuation of the dispenser. In addition, it is sometimes desirable to dispense the liquid in the form of a foam. Foam is generally made by injecting air into the liquid to create a foamy mixture of liquid and air bubbles.

SUMMARY

Exemplary embodiments of foam dispensers and refill units are disclosed herein. An exemplary foam dispenser includes a housing, a plate located in the housing, a first dispensing wheel located proximate the plate. The first dispensing wheel has a plurality of pinch members and is rotatable about an axis. The exemplary dispenser includes a second dispensing wheel located proximate the plate. The second dispensing wheel having a plurality of pinch members and rotatable about the same axis as the first dispensing wheel. Rotation of the first dispensing wheel is configured to pinch a first flexible tube against the plate and to move a first liquid through the first tube; and rotation of the second dispensing wheel is configured to pinch a second flexible tube against the plate and to move a second liquid through the first tube. The exemplary dispenser includes a motor for rotating the first and second dispensing wheels and a motor controller for starting and stopping the motor.

An exemplary refill unit for a foam dispensing system includes a first container holding a first liquid and a first outlet tube extending away from the first container. In addition, the refill unit includes a second container holding a second liquid and a second outlet tube extending away from the second container. The first liquid and the second liquid chemically react when combined with one another. The refill unit includes a space between the first liquid tube and the second liquid tube for receiving a plate therebetween. A mixing tube is also included and each of the first outlet tube and the second outlet tube are fluidically connected to the mixing tube, such that a mixing chamber is formed within the mixing tube at a point where the first liquid mixes with the second liquid. A sealing member to seal the first outlet tube and second outlet tube when the refill unit is not installed in a dispenser is also included. The first outlet tube and the second outlet tube have a flexible portion which is disposed within a pinching region of the foam dispensing system, such that at least one pinching element of the dispensing system successively engages and disengages the flexible portion of the first outlet tube and the second outlet tube, to thereby cause the first liquid and the second liquid to enter the mixing chamber and form a mixture that expands to become a foam.

An exemplary foam dispensing system includes a first container holding a first liquid and a first outlet tube extending away from the first container. It also includes a second container holding a second liquid and a second outlet tube extending away from the second container. A mixing tube is also provided wherein each of the first outlet tube and the second outlet tube are fluidically connected to the mixing tube, such that a mixing chamber is formed within the mixing tube at a point where the first liquid mixes with the second liquid. A first dispensing wheel is mounted on a shaft defining an axis of rotation for the first dispensing wheel. The first dispensing wheel includes at least one pinching element disposed on an interior side of the first dispensing wheel which is adjacent to at least one of the first outlet tube, the second outlet tube, and the mixing tube. A second dispensing wheel mounted is mounted on the shaft. The second dispensing wheel includes at least one pinching element disposed on an interior side of the second dispensing wheel which is adjacent to at least one of the first outlet tube, the second outlet tube, and the mixing tube. An actuator is provided for rotating the first and second dispensing wheels around the axis of rotation such that, as the first and second dispensing wheel rotate, the pinching elements successively engages and disengages at least one of the first outlet tube, the second outlet tube, and the mixing tube, to thereby cause the first liquid and the second liquid to enter the mixing chamber and form a mixture that expands to become a foam.

The systems and refill units for dispensing a mixture of multiple liquid supplies disclosed herein provide a simple and economical pumping system.

DETAILED DESCRIPTION

FIGS. 1 and 2are partial cross-sectional views of an exemplary dispensing system100for mixing and dispensing multiple supplies of liquids. The exemplary dispensing system100disclosed and described herein is an electrically-operated, touch-free dispenser. Thus, the dispensing system100includes an electrical power supply101. The electrical power supply101may be provided by one or more batteries, or a transformer and/or rectifier connected to a separate power source, or combinations thereof. However, other types of dispensers may be used, such as for example manually-operated dispensers. Manual dispensers may be actuated without the need for an electrical power supply by manipulating a manual actuator such as a push actuator, a lever actuator, a pull actuator, a turn actuator or the like.

The dispensing system100includes a housing102which encloses a first liquid container110with a first outlet tube111, a second liquid container120with a second outlet tube121, a motor103, a rotating shaft104, two dispensing wheels130mounted on the shaft104, a mixing outlet tube140, and a rigid plate member105. First and second container110,120and other parts are shown schematically and are not to scale. Some of these components may together form a unitary refill unit103which is separable from the other components inside the housing102to permit an easy, fast, and hygienic refilling process for the dispensing system100. In that event, the dispensing system100may include a holder106for receiving and securing the refill unit103within the housing102. The interaction (not shown) between the refill unit103and the holder106may take any convenient form, such as for example a rotatable lock ring, interlocking tabs and slots, and the like. Dispenser system100includes a sensor109for determining a position of the dispensing wheel.

In a first example, a refill unit103may be formed by the combination of the first container110and the second container120, together with their respective outlet tubes111and121, in one unit. In that event, when one or both of the containers110and120becomes empty of liquid, the refill unit103may be removed from the housing102and replaced with another refill unit103having filled containers110and120. In this first example, one or more separable fluidic connections are provided between the outlet tubes111and121and the mixing tube140, which remains inside the housing102as the refill units103are exchanged. Thus, the replacement refill unit103may conveniently include one or more plugging elements attached to the free end(s) of the outlet tubes111and121in order to prevent liquid from spilling out of the containers prior to installation. The user may then simply remove the plugging element(s) when the replacement refill unit103is inserted into the dispensing system100. The plugging element(s) may be formed so that, if the user forgets to remove the plugging element(s) before inserting the replacement refill unit103into the housing102, the housing102will not properly close. In that way the user is alerted that the plugging element(s) need to be removed in order for the recharged dispensing system100to operate.

In a second example, a refill unit103may be formed by the combination of the first liquid container110with the first outlet tube111, the second liquid container120with the second outlet tube121, and the mixing outlet tube140, all together in one unit. This embodiment has the advantage that all of the components of the system100which come into physical contact with liquid are part of the refill unit103. Thus, when an empty refill unit103is replaced, the user does not need to undo or make any liquid-tight connections. One or both of the dispensing wheels130may be dismounted from the shaft104in order to facilitate the respective removal and installation of these refill units103.

Two representative examples of a refill unit103have been provided herein. Of course, other combinations of components into a refill unit103are also possible. Either of the two examples provided here, or yet other refill units103, may include a clipping element (not shown) in order to help prevent leakage of liquids from the refill unit103when it is not installed within a dispensing system. The clipping element has a closed position, in which it prevents liquid from escaping the refill unit103. The clipping element also has an open position, in which it allows liquid to escape from the refill unit103. The clipping element may be user-operated to switch between the closed and open positions as the refill unit103is inserted into or removed from the housing102of the system100. The housing102of the system100may be configured to prevent a full installation of the refill unit103without removal of the clipping element by the user. Or, the housing102may include a mating element (not shown) which interacts with the clipping element on the refill unit103to automatically open the clipping element upon proper installation, or to automatically close upon removal.

The exemplary touch-free electrically operated dispensing system100includes an object sensor107exposed to the exterior of the housing102, and electrically connected to a motor controller108. The motor controller108includes associated circuitry for using the sensor107to detect an object in close proximity to the sensor107(such as a user's moving hand). In response to detecting an object, the motor controller108operates the motor103to initiate a liquid dispensing action. The motor103therefore rotates the shaft104and the two dispensing wheels130mounted on the shaft104. Although not shown, one or more gears may be disposed between the motor103and the shaft104to effectuate a proper rotation of the shaft104. In any event, rotation of the dispensing wheels130on the shaft104dispenses a dose of a mixture of liquids from the containers110and120, as described in more detail below. For the sake of simplicity in the figures, the object sensor107of the dispensing system100is shown as being disposed in proximity to the containers110and120, relatively far above the mixing outlet tube140. In other embodiments (not shown), the object sensor107may conveniently be disposed in a close proximity to the mixing outlet tube140.

A similar actuation may occur in manually-operated dispenser embodiments (not shown). In a manually-operated dispenser, the user operates a manual actuator disposed on the exterior of the housing102, which in turn is connected to a gearing or other transmission within the housing102to rotate the shaft104and initiate a liquid dispensing action.

The first liquid is different in composition from the second liquid. In one such embodiment, the first liquid includes a weak acid and the second liquid includes a weak base. When the two liquids combine in the mixing tube140, a gas is formed, and the mixture expands and forms a foam. The foam may be a soap, a sanitizer or a lotion. In addition, one or both of the liquids may contain a wax. The gas created by the combination of the two liquids mixes with, and is trapped in, the wax to form a thick foam. Again, the thick foam may be a soap, sanitizer or lotion.

In other embodiments (not shown), additional containers for holding yet additional liquids or other additives may be included. Accordingly, some dispensers and refill units103mix and dispense mixtures of three or more liquids. The structure and operations disclosed herein with respect to the two liquid component system100may readily be applied to such larger systems. For example, a third liquid container with a third outlet tube may be added to the illustrated dispensing system100, such that the third liquid outlet tube is disposed next to one of the other two liquid outlet tubes111and121already present in the system100.

As discussed above, the dispensing system100includes a first outlet tube111in fluid communication with the first container110and a second outlet tube121in fluid communication with the second container120. Although not shown, either one or both of the container outlet tubes111and121may include a one-way liquid valve disposed between its respective container and the mixing outlet tube140. Such a one-way liquid valve may be any type of one-way valve, such as for example, a mushroom valve, a flapper valve, a plug valve, an umbrella valve, a poppet valve, or a duck-bill valve. If utilized, the one-way valve helps to ensure liquid flows only in the direction moving from the containers110and120to the mixing outlet tube140, and not in the opposite direction.

Each one of the container outlet tubes111and121leads to a common mixing outlet tube140. In the particular embodiment of the illustrated dispensing system100, each container outlet tube111and121is circular in cross-section, and enters into the elongated mixing tube140as shown inFIG. 3. In other embodiments, the various tubes may comprise a single structure, or any suitable combination of separate components. Thus, for example, the two outlet tubes111and121may together form one integral “V”-shaped structure, which is then fluidically connected to the mixing outlet tube140to form an overall “Y”-shaped structure. As described further below, a portion of one or more of the liquid delivery tubes111,121and140is disposed between the two dispensing wheels130. Those portions are at least partially comprised of a flexible material which is successively pinched and released by the dispensing wheels130in order to pump liquid through the system. Suitable flexible tube materials include, for example, latex rubber, polyisoprene, silicone, EPDM rubber, nitrile rubber and the like. Other portions of the tubes111,121and140which are disposed above or below the dispensing wheels130may comprise a flexible material like the portions between the wheels130, or alternatively a more rigid material if desired.

FIGS. 4 to 7illustrate at least a portion of a dispensing actuation of the dispenser system100. For purposes of clarity, dispensing wheel130is illustrated with outlines so the outlet tubes111,121are visible. During that actuation, an interaction between the rotating dispensing wheels130and one or more of the flexible tubes111,121and140disposed between the dispensing wheels130dispenses a supply of foam402from the mixing outlet tube140.FIG. 8shows a perspective view of a dispensing wheel130. Thus, each dispensing wheel130has an interior side131which faces the liquid delivery tubes111,121, and an exterior side132which faces away from the liquid delivery tubes111,121. The interior side131of the wheel130includes pinching elements133and bumper elements134. Two wheels130are mounted on the rotating shaft104so that, as the respective interior sides131face each other, the pinching elements133of one wheel130are aligned with the pinching elements133of the other wheel130. Similarly, the bumper elements134of one wheel130are aligned with the bumper elements134of the other wheel130. While the wheels130as shown in the figures are circular-shaped, other embodiments may use wheels of other shapes such as a triangle, a square, a hexagon, an oval or the like.

In the illustrated dispensing system100, each dispensing wheel130includes four pinching elements133a,133b,133cand133dequally spaced around the wheel130. Also, each dispensing wheel130includes four bumper elements134a,134b,134cand134dequally spaced around the periphery of the wheel130at the same radial positions as the four pinching elements133(seeFIG. 8). One of ordinary skill in the art, upon reading the present disclosure, will understand that many different configurations of pinching elements133and bumper elements134may be used. Thus, only a single pinching element133may be used, up to any maximum number permitted by the size of the wheel130and the size of the pinching elements133on the wheel. And, any number of bumper elements134may be used, including zero bumper elements. In additional embodiments, the positioning of the pinching elements and the bumper elements may be unevenly spaced around the periphery of the wheel130. And, the respective pinching elements and bumper elements may be disposed along different radii of the wheel130. In some cases, it may even be advantageous to offset the pinching elements133of one wheel130from the pinching elements133of the other wheel130. Further, one dispensing wheel130may have more or less pinching elements133then the other dispensing wheel130

In the illustrated dispensing wheel130embodiment, the pinching elements133and the bumper elements134are formed as protuberances on the interior side131of the dispensing wheel130. One of ordinary skill in the art, upon reading the present disclosure, will understand that many different forms of pinching elements133and bumper elements134may be used. Thus, as one example (not shown), each pinching element may comprise a roller rotatably mounted on a shaft which extends in the radial direction of the wheel130. Such an embodiment would help to reduce the friction generated between the pinching elements123and the liquid delivery tube(s)111,121caught between the pinching elements123, described further below. As another example (not shown), the pinching elements123may comprise spring-loaded projections on the interior side131of the wheel130.

FIG. 4shows the exemplary dispensing system100in an initial resting state400. In that initial resting state400, the opposed pinching elements133aof the dispensing wheels130squeeze the flexible container outlet tubes111and121between the pinching elements133aat a pinch point. That prevents liquid(s) from flowing past the pinch point, upwards or downwards within the tubes111and121. A plate105may optionally be disposed between the two container outlet tubes111and121in order to increase the efficacy of the pinching elements133a. In other embodiments, only the flexible tubes111and121may be disposed between the wheels130, without any further supports or other elements.

In the initial resting state400, the pinching elements133adefine a primed downstream portion402and an upstream portion404within each flexible outlet tube111and121. The opposed pinching elements133blocated downstream of the pinching elements133asimilarly form a pinch point of the outlet tubes111and121. Thus a primed charge402of each liquid is separately captured within the respective outlet tubes111and121between the sets of pinching elements133aand133b.

During operation, upon detecting an object through sensor107, the motor controller108operates the motor103to rotate the shaft104in the direction R. The dispensing wheels130are correspondingly rotated from the initial resting state400to the first intermediate state500illustrated inFIG. 5. The rotation frees the flexible outlet tubes111and121from the two downstream pinching elements133b. Once freed, the flexible outlet tubes111and121act as a self-biasing member and expand out to an un-pinched diameter, to permit the primed charge402of liquid to flow past the now-released pinch point. At the same time, the continued pinching of the flexible outlet tubes111and121between the two upstream pinching elements133aforces the primed liquid charge402within the outlet tubes111and121to move downwardly within the tubes. And, the next pair of pinching elements133drotate closer to the flexible outlet tubes111and121.

The two liquids forming the primed charge402collide together and begin mixing in the flexible mixing tube140downstream of the pinching elements133a. A mixing chamber is formed in the flexible mixing tube140at the point where the two container outlet tubes111and121empty into the common flexible mixing tube140. In some embodiments, the flexible mixing tube140is made to narrow in the region of the mixing chamber to cause the liquids to mix more forcefully, such as with a conical shape or other tapered shape. In some embodiments, the interior surface of the flexible mixing tube140may alternatively or additionally be provided with baffles in the region of the mixing chamber to increase the mixing of the liquids.

The mixing outlet tube140leads down to exit the housing102of the dispensing system100. Typically, the chemical reaction between the mixed liquids continues to form a foamy product as the mixture continues its journey down the tube140. The distal end of the mixing outlet tube140outside of the housing102may simply be an open end of the tube140from which the mixed foam is dispensed for use by the person who actuated the dispensing system100. In other embodiments, an outlet nozzle (not shown) may be secured to the distal end of the mixing outlet tube140. In some embodiments, the outlet nozzle has a conical shape or is otherwise narrowed to promote additional mixing of the two or more liquids and enhance the quality of the foam output. In some embodiments, the outlet nozzle includes one or more baffles that cause turbulence to the liquids passing through and vigorously mixes the liquids together to increase the reaction occurring between the liquids. In addition, the outlet nozzle may include a one-way outlet check valve, such as the one-way valves identified above.

The motor controller108operates the motor103to continue the rotation of the shaft104in direction R from the first intermediate state500to the second intermediate state600ofFIG. 6. The continued pinching of the flexible outlet tubes111and121between the pinching elements133aprevents liquid(s) within those tubes from flowing past the pinch point, upwards or downwards. Thus, as the dispensing wheels130rotate in direction R, the pinching elements133adefine a primed upstream portion602of the outlet tubes111and121. The next opposed pinching elements133dsimilarly engage with and form a pinch point of the flexible outlet tubes111and121. Thus a primed charge602of each liquid begins to be captured within the respective outlet tubes111and121between the sets of pinching elements133aand133d.

The rotation in direction R of the dispensing wheels130continues from the second intermediate state600to the third intermediate state700ofFIG. 7. The continued pinching of the flexible outlet tubes111and121between the downstream pinching elements133aprevents liquid(s) within the tubes111and121from flowing past the pinch point, upwards or downwards. The upstream pinching portions133dsimilarly fully engage the flexible outlet tubes111and121to prevent liquid(s) within the tubes111and121from flowing past the upstream pinch point. Thus, in the third intermediate state700, a primed charge602of each liquid is fully and separately captured within the respective outlet tubes111and121between the sets of pinching elements133aand133d.

As will be appreciated, the third intermediate state700ofFIG. 7is identical to the initial resting state400ofFIG. 4, after the wheels130have undergone a 90° rotation. During the rotation R of the wheels130from the initial resting state400to the third intermediate state700, the flexible container outlet tubes111and121have been released by pinch member133band pinched pinch member133done time. In some embodiments, the motor controller108may then stop the rotation in direction R of the dispensing wheels130in the state700, which in those embodiments becomes a final resting state of the dispensing system100. The system100then remains in that resting state until the controller108again detects an object through the object sensor107outside of the dispensing system100, when the dispensing cycle begins anew starting at the initial resting state400shown inFIG. 4.

In other embodiments, however, a single dispensing action will result in more than one pinch being applied to the flexible liquid delivery tubes between the dispensing wheels130. In these embodiments, the motor controller108will continue the rotation in direction R of the dispensing wheels130upon reaching the third intermediate state700. The rotation cycle then continues, as described above starting at the position400. The motor controller108is programmed to rotate the dispensing wheels130for a sufficient time to dispense a desired amount of foamed liquid. For example, the various parts of the system100may be dimensioned so that the primed charge402is only about 0.45 cubic centimeters. Eventually the rotation stops, preferably with the wheels130in a final position700ofFIG. 7. Thus, dosing sizes of the dispensing system100may be altered by programming different rotation times into the motor controller108. Accordingly, the dispensing system100is a variable dosing pump.

It may be advantageous in some embodiments to include a tracking means which permits the motor controller108to monitor the position of the dispensing wheels130within their rotation. For example, the motor controller108may then ensure that the wheels130are stopped in the position700ofFIG. 7. One of ordinary skill in the art will know of many such tracking means, as the state of the art exists at the present time or in the future. In one example, the tracking means may comprise a motor encoder (not shown) which monitors the operation of the motor103, as is well known in the art. In another example, the tracking means may comprise a nub or other element disposed on the wheel130which contacts a switch (not shown) as the wheel130rotates, as is also well known in the art. In yet another example, the tracking means may comprise a magnetic sensor (not shown) which monitors one or more permanent magnets disposed on the exterior side132or on the periphery of a wheel130as it rotates, as is also well known in the art. Optionally, a sensor (not shown) may be used to determine the position of the dispensing wheel130. The sensor may be any type of sensor that provides an output indicative of a position of the dispensing wheel130.

In the particular system100illustrated and described above, only the two container outlet tubes111and121are pinched by the rotation of the dispensing wheels130. In other embodiments (not shown), a flexible portion of the mixing outlet tube140may be disposed in between the wheels130to be pinched during the rotation.

Each one of the pinched tubes forms a variable volume passage which is compressed and stretched under the pinching of the dispensing wheels130. That is, the pinching elements133of the wheels130first engage and then release the pinched tubes as the wheels130rotate in direction R. When released, each pinched tube acts as a self-biasing member and expands out to an un-pinched diameter, to permit liquid to flow past the now-released pinch point. In some embodiments, the compressing and stretching prevents waxy residue and other liquids from adhering to and building up within the pinched tubes.

In addition, bumper elements134may optionally be disposed on the interior side131of one dispensing wheel130or both dispensing wheels130to supplement the tube cleaning action of the pinching elements133. As the dispensing wheels130rotate in direction R, the bumper elements134contact the sides of the flexible tubes111,121and the mixing tube140disposed between the wheels130to knock out wax and other residue, and also to agitate the mixing action within the mixing tube140. Minimizing such residues helps prevent blockage of the tubes.

To insert refill unit103into dispenser housing102, a user moves a lever (not shown) to the load position that opens the area between dispensing wheels130and secures the refill unit to holder106. The user pulls the end of the mixing outlet tube140over the plate105so that outlet tube111is on one side and outlet tube121is on the other. The user moves the lever back to the run position and the dispensing wheels130move back in and pinch the outlet tubes111,121. In some embodiments, the user removes a clip (not shown) that pinches outlet tubes111,121shut so liquid does not leak during shipment. In one embodiment, one or more projections (not shown) secured to the lever and when the lever is moved to the run position, the one or more projections expand the clip to allow fluid to flow through the lines. When the lever is moved to the load position, the one or more projections move and allow the clip to contract to seal the outlet tubes111,121. In another embodiment, a plug (not shown) is located in the mixing outlet tube140and extends into the first and second outlet tubes111,121and is pulled out by a user after the refill unit130is installed. The plug may be retained to plug the end when the refill unit103is removed.

By minimizing such residues, this cleaning action also can help to prevent dripping of residual liquids which remain within the system100after a dispensing action is complete. Nonetheless, the dispensing system100may additionally include a drip catcher (not shown) in the outlet mixing tube140downstream of the mixing chamber. The drip catcher may be, for example, an annular projection that projects upward within the channel of the outlet mixing tube140. Such a drip catcher catches any residual liquid or foam that travels down the walls of the flexible mixing outlet tube140after the dispensing cycle has been completed and the actuating object has been removed from the vicinity of the object sensor107.

While the present invention has been illustrated by the description of embodiments thereof and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Moreover, elements described with one embodiment may be readily adapted for use with other embodiments. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicants' general inventive concept.