Patent Publication Number: US-7222756-B2

Title: Self-contained, portable and automatic fluid dispenser

Description:
FIELD OF THE INVENTION 
   The invention relates to a device for dispensing fluid. In particular, a self-contained, portable and automatic fluid dispenser that is capable of dispensing fluid of various viscosity. 
   BACKGROUND OF THE INVENTION 
   Dispensers of fluid or liquid are commonly used in industrial, business, residential and hospital settings. The most common type of fluid dispensers have plunger pumps with the soap container at the bottom wherein a user pushes a lever or handle downward to draw fluid upward for ejection at a nozzle near the top. Disadvantageously, this type of dispenser requires the user to push the lever or pump handle numerous time upon initial use to draw sufficient fluid upward for dispensing at the nozzle. When this type of dispenser has not been used for a period of time, fluid in the pump sometimes flows back to the soap container due to gravity and again requires numerous pumping before fluid is dispensed. 
   Since fluid dispensers are often used to dispense cleansing or disinfecting fluids such as soap and anti-microbial gel, it is preferable that the fluid dispensers dispense the fluid without the user contacting the dispensers. Some prior art dispensers have incorporated infrared sensors such that upon detection of a user&#39;s hand near the sensors, a predetermined amount of fluid is dispensed. Prior art automatic dispensers are usually wall-mounted or sink-mounted and are powered via electrical outlets. Disadvantageously, these type of mounted automatic dispensers are expensive and not portable. Further, a malfunctioned mounted automatic dispenser requires either a technician for on-site servicing or a technician for often complicated disassembling of the dispensers for off-site servicing. 
   U.S. patent application Publication No. 2004/0050875 discloses a liquid dispenser that is battery powered and portable. This dispenser also provides a sensor for automatic dispensing of liquid. This dispenser utilizes a rotating helical screw pump to draw fluids from a liquid container at the bottom upward for ejection at a nozzle near the top. Similar to the plunger pump dispensers, disadvantageously, liquid is dispensed with a time delay since it requires numerous rotation of the helical pump to draw sufficient fluid upwards for dispensing at the nozzle. Further, liquid in the helical screw pump is more prone to flow back to the liquid container than the plunger pump, thereby resulting in time delay in dispensing liquid each time the dispenser is used. Another disadvantage is that this prior art liquid dispenser cannot be used to dispense fluid with high viscosity, such as gel, because the rotation of the helical screw pump against the gel along the helical pump causes the viscosity characteristic to break down and liquefies the gel. 
   Therefore, there is a need for a fluid dispenser that automatically and promptly dispenses fluid of various viscosity, be self-contained and portable. 
   SUMMARY OF THE INVENTION 
   The present invention provides a fluid dispenser that automatically and promptly dispenses fluid of various viscosity and is self-contained and portable. 
   The fluid dispenser of the present invention is preferably battery operated and dispenses different viscosity fluid such as lotion, soap, gel sanitizer, mouthwash, etc. The fluid dispenser has a sensor, preferably infrared, that upon detecting the presence of a user&#39;s hand, the dispenser, controlled by an integrated circuit (IC) chip, automatically dispenses a predetermined amount of fluid. 
   The fluid dispenser comprises a housing, a sleeve reservoir and a container for storing fluid. The housing has a nozzle for dispensing the fluid and contains the power source, sensor, integrated circuit chip and pump assembly. The pump assembly comprises a motor and gears within the housing and a shaft combination that extends beyond the housing. The shaft combination comprises a pipe and a helical shaft positioned coaxially within the pipe. The motor, via gears, rotatingly drives the helical shaft relative to the pipe. 
   The sleeve reservoir is a cylindrical tube with open upper and lower ends. At the lower end of the sleeve reservoir is a ball valve. Near the upper end of the sleeve is a plurality of overflow openings. 
   The container has a cylindrical neck portion. The sleeve reservoir is first inserted through the neck portion into the container before fluid is poured into the container. Excess fluid overflows from the overflow openings of the sleeve into the container. With the housing resting on top of the container, the shaft combination of the pump assembly is inserted co-axially into the sleeve reservoir within the container, submerging the shaft combination in the fluid. The fluid floods the space between the helical shaft and the pipe of the shaft combination. As a result, upon initial rotation of the helical shaft, fluid is dispensed from the nozzle of the housing with minimal delay. When fluid is drawn upward by the helical shaft and is dispensed, the fluid in the sleeve reservoir is continuously replenished from the container through the ball valve, thereby maintaining a high level of fluid in the shaft combination. 
   In a preferred embodiment, a rotating dial is provided on the housing to control the speed of the motor and helical shaft by varying the resistance and voltage to the motor. By changing the motor and shaft rotation speed, a user can adjust the fluid dispenser for dispensing different viscosity fluid or such that different amount of fluid is dispensed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the present invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification wherein: 
       FIG. 1  is the front view of the fluid dispenser of the present invention. 
       FIG. 2  is the side view thereof. 
       FIG. 3  is an exploded view of the components of the fluid dispenser. 
       FIG. 4  is the cross-sectional view taken along line  4 — 4  in  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to the drawings, wherein the same reference number indicates the same element throughout, there is shown in  FIGS. 1–3  a fluid dispenser  10  of the present invention. Fluid dispenser comprises a housing  12 , a sleeve reservoir  14  and a container  16  for storing fluid  18 . Housing  12  sits on top of and correspondingly mates with container  16 . 
   Housing  12  has a nozzle  20  for dispensing fluid  18  from the container  16 . Nozzle is preferably extended slightly beyond the housing  12  to prevent droplets of fluid  18  from forming at the nozzle  20 . The housing  12  has a sensor  22  that detects the presence of a user&#39;s hand or an object to dispense fluid  18  from the container  16 . Sensor  22  is preferably an infrared sensor, which is known to one skilled in the art of electronics. Housing  12  contains the power source  23  and an integrated circuit (IC) chip  24  and a pump assembly  26 . Power source  23  is shown as a plurality of batteries. However, the fluid dispenser  10  may be adapted, as known to one skilled in the art of electronics, to be powered by alternating current from an outlet. The IC chip  24  provides a signal to the power source  23  to release current to the pump assembly  26  for dispensing fluid  18  upon receiving a signal from sensor  22 . Electrical connection among the power source  23 , sensor  22 , IC chip  24  and pump assembly  26  are not shown to simplify the drawings since it is known to one skilled in the art of electronics how this is accomplished. IC chip  24  signals to the pump assembly  26  how long to stay on after the sensor  22  is actuated to dispense a predetermined amount of fluid  18 . The length of time for the operation of the pump assembly  26  to remain on can also depend on the selected viscosity of the fluid  18  being dispensed. 
   The pump assembly  26  comprises a motor  28  and gears  30  within the housing  12  and a shaft combination  32  that extends beyond the lower portion of housing  12 . The shaft combination  32  comprises a pipe  34  and a helical shaft  36  coaxially within the pipe  34 . The widest diameter extent of the helical shaft  36  is slightly smaller than the internal diameter of pipe  34 . The motor  28 , via the gears  30 , rotatingly drives the helical shaft  36  relative to the pipe  34  to draw fluid  18  upward from the container  16 , through the pipe  34  to a conducting pipe  38  and out of the nozzle  20 . The IC chip  24  controls the length of time of the pump assembly  26  remains operating by controlling the number of turns of the helical shaft  36  to control the amount of fluid  18  being dispensed. Conducting pipe  38  has a length and sharp angle near the nozzle  20  to control the momentum of the fluid  18  and avoid dripping of excessive fluid  18  after each actuation of the pump assembly  26 . 
   The sleeve reservoir  14  is a generally cylindrical tube  40  with open upper and lower ends  42  and  44 , respectively. The diameter of the cylindrical tube  40  is slightly larger than the pipe  34  to form an annular gap. At the lower end  44  of the tube  40  is a ball valve  46 . Preferably, the ball valve  46  comprises a precise ball used for ball bearings. Near the upper end  42  of the tube  40  is a plurality of overflow openings  48 . The upper end  42  of the tube  40  has an enlarged portion  50  with a fold-over annular lip  52  defining a circular groove  54  between the lip  52  and the outer circumferential wall  56  of the tube  40 . The internal wall of the lip  52  has reverse threading. The outer wall of the annular lip  52  has threading that correspondingly receives threading in the lower portion of housing  12  near the proximal end of the shaft combination  32 . 
   The container  16  has an opening  58  at a cylindrical neck portion  60 . The outer wall of the neck portion  60  has reverse threading that correspondingly receives the reverse threading on the internal wall of the annular lip  52  of the sleeve reservoir  14 . 
   To assemble the fluid dispenser  10  for use, the sleeve reservoir  14  is first inserted into the opening  58  of the container  16 , with the reverse threading on the sleeve reservoir  14  correspondingly engaging the reverse threading on the container  16 . Upon full insertion of the sleeve reservoir  14  into container  16 , the lower end  44  of the sleeve reservoir  14  is a short distance away from the bottom of the container  16 . Fluid  18  is then poured into the container  16 . Fluid  18  first fill the cavity of tube  40  of the sleeve reservoir  14 , then with the excess fluid  18  overflowing from the overflow openings  48  into the container  16 . Shaft combination  32  is then inserted co-axially into the sleeve reservoir  14 , submerging the shaft combination  32  in the fluid  18  within the sleeve reservoir  14 . Fluid  18  floods the space between the pipe  34  and helical shaft  36 . Threading at the lower portion of housing  12  near the proximal end of the shaft combination  32  matingly engages the threading on the outer wall of the annular lip  52  of the sleeve. Upon engaging the housing  12  to the sleeve reservoir  14 , and thereby, the container  16 , the distal end of the shaft combination  32  is a short distance away from the ball valve  46  of the sleeve reservoir  14 . 
   The fluid dispenser  10  of the present invention advantageously dispenses fluid  18  with minimal delay because fluid  18  is already present in the shaft combination  32  and upon actuation of the motor  28  and gears  30  via sensor  22 , fluid  18  is readily dispensable at the nozzle  20 . Further, due to the presence of fluid  18  in the shaft combination  32  at all time, high viscosity fluid such as gel can be dispensed without losing the high viscose characteristic because of the minimal interaction of the helical shaft  36  against the gel. When fluid  18  is drawn upward by the shaft combination  32  and is dispensed from the nozzle  20 , the suction of the fluid  18  from sleeve reservoir  14  lifts the ball valve  46  from the lower end  44  to allow fluid  18  from the container  16  to replenish the fluid  18  in the sleeve reservoir  14 . When the fluid dispenser  10  ceases dispensing fluid  18 , the weight of the fluid  18  within the sleeve reservoir  14  and gravity pulls the ball valve  46  down the lower end  44  and prevents fluid  18  in the sleeve reservoir  14  to flow freely back into the container  16 , thereby maintaining a high level of fluid  18  within the sleeve reservoir  14  and the shaft combination  32 . 
   In an alternate embodiment, a rotating dial  62  is provided on the housing  12  to allow a user to control the speed and rotation of the motor  28  and helical shaft  36  by varying the resistance and voltage applied to the motor  28 , which is known to one skill in the art of electronics. By varying the rotation speed of the motor  28  and helical shaft  36 , a user can adjust the amount of fluid  18  being dispensed and can adapt the fluid dispenser  10  for different viscosity fluid  18 . 
   The features of the invention illustrated and described herein is the preferred embodiment. Therefore, it is understood that the appended claims are intended to cover the variations disclosed and unforeseeable embodiments with insubstantial differences that are within the spirit of the claims.