Abstract:
A fluid dispenser includes a container configured to store a fluid, a pump for placement in an interior of the container and for pumping contents of the container to an exterior of the container, a motor system for driving the pump and including a rotor for placement in the interior of the container, and a stator for placement on the exterior of the container, wherein an electric current is passed through the stator for causing rotation of the rotor.

Description:
BACKGROUND 
       [0001]    The present invention relates to the field of pump operated dispensers. 
         [0002]    Pump operated dispensers, such as soap dispensers used to dispense liquid hand soap in public restrooms, deliver contents from a container of the dispenser to a dispensing portion that may be located at or near a top of the container. 
         [0003]    “Touchless” soap dispensers typically utilize an electric motor that drives a pump to which it is coupled, and that is activated in response to a signal delivered upon the activation of a switch or sensor of the dispenser system, such as a motion detector or other optic sensor. Upon receiving the signal, the rotor rotates to drive a drive shaft of the pump located within the container to dispense an amount of soap. Such a configuration may require the motor to be mounted within the container of the soap dispenser, or may require a physical connection through a portion of the container for physically coupling the motor to the mechanics of the pump located within the container to drive the drive shaft. However, submersible motors require special sealing to protect components of the motor, while physical connections through the container may require special sealing of the system to prevent liquid from leaking from the container. Furthermore, such configurations may lead to deterioration of the motor and the moving parts associated with the mechanics of the pump due to stress and friction. Thus, a fluid dispenser having fewer parts and/or fewer mechanical couplings is desired. 
       SUMMARY 
       [0004]    According to embodiments of the present invention, a pump located within a container is operated by rotation of a rotor coupled to a drive shaft of the pump to dispense fluid contents of the container by driving the pump. The rotor includes one or more magnets, and is driven by a rotating magnetic field created by a plurality of coils that are located on an exterior of the container in sufficient proximity to the magnets of the rotor. 
         [0005]    According to one embodiment of the present invention, there is provided a fluid dispenser including a container configured to store a fluid, a pump for placement in an interior of the container and for pumping contents of the container to an exterior of the container, a motor system for driving the pump and including a rotor for placement in the interior of the container, and a stator for placement on the exterior of the container, wherein an electric current is passed through the stator for causing rotation of the rotor. 
         [0006]    The fluid dispenser may further include a cap configured to be coupled to the container, and the pump may be configured to be coupled to the cap. 
         [0007]    The cap may be configured to be threadably coupled to the container. 
         [0008]    The stator may include three coils electrically coupled in a delta pattern or a star pattern. 
         [0009]    The three coils may be shaped to form a ring and may be configured to be driven by three half bridges in an open loop. 
         [0010]    The fluid dispenser may further include a processor for regulating the electric current through the stator, and a sensor for sensing an object proximate the sensor and for sending a sensor signal to the processor. 
         [0011]    The pump may be for pumping the contents in response to the sensor signal generated by the sensor. 
         [0012]    The electric current through the stator is regulated using at least one of a pulse-width modulated (PWM) signal or variable frequency. 
         [0013]    The sensor signal may be generated upon detection of motion of a user. 
         [0014]    The processor may be configured to have the electric current passed through the stator upon receiving the sensor signal. 
         [0015]    The fluid dispenser may further include a flexible circuit for carrying at least one of the sensor signal and the electric current through the stator. 
         [0016]    The rotor may include a ring magnet. 
         [0017]    The fluid dispenser may further include a battery for delivering the electric current through the stator. 
         [0018]    The fluid dispenser may further include a processor configured to regulate electric current through the stator corresponding to a voltage level of the battery. 
         [0019]    The fluid dispenser may further include a dispensing end fluidly coupled to the pump for dispensing the fluid pumped by the pump. 
         [0020]    The fluid dispenser may further include a drive shaft for coupling the pump to the rotor. 
         [0021]    The electric current may cause the stator to produce a magnetic field substantially surrounding the rotor for causing rotation of the rotor. 
         [0022]    The rotor may include a plurality of magnets. 
         [0023]    According to another embodiment of the present invention, there is provided a motor system for driving a pump for pumping contents of a container includes a rotor for placement in an interior of the container, and a stator for placement on an exterior of the container. 
         [0024]    According to yet another embodiment of the present invention, there is provided a pump assembly including a container, a pump for pumping contents of the container, and a motor system for driving the pump and including a rotor for placement in an interior of the container, and a stator for placement on an exterior of the container. 
         [0025]    According to another embodiment of the present invention, there is provided a method of dispensing a fluid from a container, the method including providing a magnetic field using a stator, moving a magnet in response to the magnetic field, driving a pump in response to the motion of the moving magnet, and pumping the fluid from the container with the pump. 
         [0026]    Accordingly, embodiments of the present invention provide a submersible pump located inside a container and magnetically driven by a magnetic field generated on an exterior of the container. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  is a cross-sectional view of a bottom cap for a container with a pump and rotor coupled thereto, and a set of coils for causing rotation of the pump rotor according to an embodiment of the present invention; 
           [0028]      FIG. 2  is a sectional view of the container of an embodiment of the present invention that is configured to be coupled to the bottom cap of the embodiment of the present invention shown in  FIG. 1 ; 
           [0029]      FIG. 3  is a perspective view of the container of the embodiment shown in  FIG. 2  assembled with a dispensing end and the bottom cap of the embodiment shown in  FIG. 1  according to an embodiment of the present invention; 
           [0030]      FIG. 4  is a partial cross sectional view of a container with a bottom cap coupled thereto and a housing containing a set of coils for causing rotation of a pump rotor according to another embodiment of the present invention; 
           [0031]      FIG. 5A  is a schematic view showing magnetic coils of a stator in a delta pattern that are powered by a battery pack and coupled to a sensor and to a processor, according to an embodiment of the present invention; 
           [0032]      FIG. 5B  is a schematic view showing magnetic coils of a stator in a star pattern, according to an embodiment of the present invention; and 
           [0033]      FIG. 6  is a perspective view of coils of a stator circumscribing/surrounding a rotor coupled to a pump, according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Embodiments of the present invention may include an assembly including a container, a container end cap, and a pumping mechanism including a pump rotor. These features may be similar to those that are disclosed in U.S. Patent Application Publication 2010/0213208 A1, which is fully incorporated herein by reference. Furthermore, other features disclosed in U.S. Patent Application Publication 2010/0213208 A1 may be incorporated with embodiments of the present invention. Accordingly, some components of embodiments of the present invention that are included in the incorporated reference are not discussed at length herein. 
         [0035]    Referring to  FIG. 1 , a bottom cap, a pump, a rotor, and a set of magnetic coils for causing rotation of the rotor of a fluid dispensing system according to a first embodiment of the present invention is shown. 
         [0036]    According to the present embodiment, a bottom cap  22  has threads  19  to enable the bottom cap  22  to be coupled to a threaded base section  14  of a container  12 , which is configured to contain a material (e.g., a fluid such as a liquid) to be dispensed, to seal a bottom opening  18  of the container  12  (see  FIG. 2 ). Coupled to the bottom cap  22  is a pump  58 . A pump  58  is mounted in a pump mount  54  at the bottom cap  22 , which is removably coupled to the bottle  12 . 
         [0037]    Although the pump  58  of the present embodiment is coupled near a bottom of the container  12 , different applications of embodiments of the present invention may be configured to have the pump  58  differently located. Furthermore, although embodiments of the present invention are described with reference to a pump for pumping a fluid or liquid, other embodiments of the present invention may be used to pump other materials, such as gasses, foams, or slurries or other types of fluids. 
         [0038]    One or more magnets  68 , such as an electromagnet, a permanent magnet, a ring magnet, or one or more magnet segments, are part of, or may be mounted on or coupled to, an impeller of the rotor  69  that is coupled to a drive shaft  62  of the pump  58  for driving the pump. The magnet or magnet segment(s)  68  act(s) as a rotor  69  of the pump  58  to be driven by a stator  91  and to be used as an integrated part of an open frame DC servo motor  20 , such as an open frame brushless DC servo motor. Driving the drive shaft  62  of the pump  58  causes the fluid contained in the container  12  to pass through an inlet  70  of the pump  58  and be pumped by the pump to an outlet  72  of the pump  58 , wherein the outlet  72  may be coupled to a tube  76  (see  FIG. 2 ) used to dispense the fluid from near the bottom of the container  12 . 
         [0039]    According to the present embodiment, the magnet or magnet segment(s)  68  may be driven by manipulating a magnetic field produced by the stator  91 , which substantially circumscribes the magnet or magnet segment(s)  68 , although different embodiments of the present invention may use various configurations of the servo motor  20 , wherein the stator  91  is able to drive the rotor  69  via the magnetic field. This magnetic field may be produced by an electromagnet, such as electromagnetic coils  24  which form the stator  91 , or may be produced by some other device that is placed in proximity to the bottle  12  so as to cause motion of the magnet or magnet segment(s)  68  attached to the drive shaft  62  of the pump  58 , causing the drive shaft  62  to rotate. Accordingly, the electromagnetic coils  24  are operated as the stator  91  of the open frame servo motor  20  of the present embodiment. Furthermore, as shown in  FIGS. 5A ,  5 B, and  6 , the electromagnetic coils  24  may consist of three coils  24   a,    24   b,  and  24   c.    
         [0040]    By using the above described open frame servo motor  20 , the fluid dispensing system  10  of the present embodiment eliminates the need for moving parts that are external to the container  12 . Furthermore, the need to align the stator  91  with the rotor  69  becomes less critical, making effective driving of the pump  58  with the stator  91  more easily accomplished. 
         [0041]    According to the present embodiment, the stator  91  includes three or more coils  24  formed in the shape of a ring to be located outside of the bottom cap  22 , allowing the stator  91  to be an open frame stator  91  without commutator, as shown in  FIG. 1 . Upon assembly, the open frame stator  91  is placed in proximity to an exterior of the bottom cap  22  housing the rotor  69 , thereby removing the need for moving parts outside of the bottle  12  that are physically coupled to parts within the bottle  12  (i.e., coupling of the motor external to the bottle to the pump within the bottle). Accordingly, embodiments of the present invention obviate the need for having an opening in the bottle  12  at the motor-pump connection, and also enable the operation of the pump  58  without a constant force directly applied to the rotor  69  and drive shaft  62 , thereby decreasing wear of the components of the dispensing system  10 . 
         [0042]    Although the present embodiment shows a bottom cap  22  that is engageable with the bottle  12 , and that may be removed from the bottle  12 , other embodiments of the present invention may include one-piece, or integrally formed, bottle/cap structure. 
         [0043]    Referring to  FIG. 2 , a container section, which is configured to be coupled to the bottom cap  22  of the embodiment shown in  FIG. 1 , of a fluid dispensing system of an embodiment of the present invention is shown. 
         [0044]    The fluid dispensing system  10  according to the present embodiment includes a substantially cylindrically-shaped bottle  12  for holding the fluid to be dispensed, although differently shaped containers may be used to contain the fluid without departing from the spirit or scope of the present invention. At the top  4  of the bottle  12  is a neck section  16 , which may be threaded  108  to threadably couple the bottle  12  to a spout dispensing end  28  (see  FIG. 3 ). Furthermore, the tube  76  coupled to the outlet  72  of the pump  58  may be coupled to the outlet  112  to deliver the fluid to the spout dispensing end  28 . 
         [0045]      FIG. 3  is a perspective view of an assembled fluid dispenser according to an embodiment of the present invention. 
         [0046]    Referring to  FIG. 3 , according to the present embodiment, the servo motor  20  may be activated in response to a signal from a motion detecting sensor  38 , an optic sensor, an infrared sensor, or some other type of switch or no-touch sensor. The sensor  38  may send an activation signal to the processor  99  (shown schematically in  FIGS. 5A and 5B ), which in turn uses, for example, software to direct the operation of the stator  91  to drive the servo motor  20 . It should be noted, however, that the servo motor  20  of other embodiments of the present invention may be driven using hardware. Furthermore, pulse-width modulated (PWM) signals may be sent to the stator, and the fluid dispensing system  10  may transmit various signals via wiring or a circuit, such as a flexible circuit  41 . 
         [0047]    The processor  99  and software may also be used to monitor a voltage drop of a battery pack  97  (shown schematically in  FIGS. 5A and 5B ) including one or more battery cells used to power the servo motor  20 . Commonly, a voltage drop of a power source used to power a DC motor would result in change in performance, or speed, of the DC motor. Therefore, if such a DC motor were coupled to the pump  58  of the present embodiment, variations in voltage applied to the DC motor could potentially lead to variations in amounts of fluid or liquid dispensed. Accordingly, if a voltage drop is sensed, the software of embodiments of the present invention is capable of adjusting the PWM signals, or otherwise controlling power to the coils  24  of the stator  91 , to ensure that a more closely uniform amount of fluid is dispensed. 
         [0048]    Although a battery pack  97  is described, other embodiments of the present invention may use a power supply other than the battery pack  97 . Furthermore, according to the present embodiment, the speed of the servo motor  20  may be controlled by controlling a frequency of a signal delivered thereto. By controlling the frequency of the signal, the rate of rotation of the magnetic field provided by the stator  91  may be more uniform, which in turn causes the speed of the rotor  69  to be more uniform. Variations in the rate of rotation of the rotor  69  may otherwise cause variations in the performance of the pump  58  (e.g., amounts of fluid pumped by the pump  58  may vary). By controlling the servo motor  20  using, for example, frequency-based signals, and PWM signals, variations in voltage delivered to the servo motor  20  will have less of an effect on performance of the servo motor  20 , and amounts of fluid or liquid output in response to activation of the sensor  38  will be more consistent. 
         [0049]    Furthermore, the software may also be used to control the speed, direction, and torque of the magnet or magnet segment(s)  68  coupled to the drive shaft  62  by adjusting and controlling the PWM signals. In the present embodiment, the open frame servo motor  20  is a brushless direct current (DC) motor  20 . Accordingly, the magnet or magnet segment(s)  68  may be driven by the set of electromagnetic coils  24  of the stator  91 , which may be driven according to the PWM signals from the processor  99  to create a rotating magnetic field in proximity to the bottle  12 . 
         [0050]      FIG. 4  shows components of a fluid dispenser according to another embodiment of the present invention. 
         [0051]    Referring to  FIG. 4 , the open frame servo motor  20  of the fluid dispenser  10  of the present embodiment includes three coils  24  electrically coupled in a delta pattern (see  FIG. 5A ) or coupled in a star pattern (also referred to as a “Y” pattern, see  FIG. 5B ) as the stator  91 . The open frame servo motor  20  may be driven by three half bridges  98   a,    98   b,    98   c  (see  FIGS. 5A and 5B ) on a PC Board in an open loop, without feedback. The three half bridges  98   a,    98   b,    98   c  may be controlled by the processor  99 , such as a microprocessor or microcontroller. An output signal of the processor  99  of the present embodiment is a pulse-width modulated (PWM) signal used to control current through the delta-connected coils  24  and to control an output sequence and frequency for controlling speed and direction of the servo motor  20 , and in turn controlling the dispensing of fluid via the spout dispensing end  28 . 
         [0052]    While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that features of different embodiments may be combined to form further embodiments, and that various changes in form and details may be made therein, without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents.