Abstract:
A vibratory pump for dispensing a fluid in a highly controllable manner includes a pumping mechanism in which a piston is slidably disposed within a chamber having an inlet and an outlet spaced from one another. The piston is shaped similarly to the interior of the chamber and is capable of moving within the chamber in a manner that prevents any fluid in the chamber from flowing between the chamber and the piston. As a result, the pumping mechanism does not require the use of any separate compressible or elastic sealing members, thereby increasing the reliability and useful life of the pump.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention related to vibrating pumps in general, and more specifically to vibrating pumps including a piston as the vibrating member. 
       BACKGROUND OF THE INVENTION 
       [0002]    Vibratory pumps are often used for dispensing selected amounts of a liquid from a reservoir of the liquid to a desired location. These pumps have various uses because of their ability to meter very precisely the amounts of fluid dispensed from the pumps, and to quickly change the dispensed amounts in response to changes in the vibratory frequency of the pumps. Therefore, these types of vibratory pumps are highly useful in a wide variety of applications. 
         [0003]    In prior art vibratory pumps, such as those disclosed in U.S. Pat. Nos. 6,315,533; 6,364,622; 6,428,289; and 6,604,920 which are commonly owned with this application and incorporated herein by reference, the vibratory pumps utilize a motor to selectively open and close a chamber that is used to pump the fluid. As the chamber is opened, the fluid enters the chamber due to a vacuum created in the chamber by the opening of the chamber. When the chamber is closed, due to the shape or components used to form the chamber, the fluid is urged out of the chamber to dispense the liquid from the pump. 
         [0004]    However, in these types of pumps, the pump requires one or more sealing members within the pump to prevent the fluid to be dispensed from flowing other than in the desired direction, and thereby limiting the effectiveness of the pump. With regard to theses types of sealing members, they are formed of material that have a certain amount of elasticity or compressibility to provide an effective seal. However, due to this property of the sealing members, over time, the sealing members can degrade, especially in the presence of certain types of fluids, such that the fluid seal becomes less effective, and ultimately fails. At this point, the sealing member needs to be replaced or, due to the severity of the failure, the pump may be damaged beyond repair. 
         [0005]    Therefore, it is desirable to develop a vibratory pump having a construction that does not include any compressible or elastic sealing members that can potentially fail and/or be negatively affected by the type of fluid being dispensed through the pump. 
       SUMMARY OF THE INVENTION 
       [0006]    According to a primary aspect of the present invention, the vibratory pump is formed with a chamber having an inlet extending into the chamber, and outlet extending out of the chamber and spaced from the inlet. The chamber also includes a shaft collar located opposite the outlet for the chamber and through which a shaft slidably extends. The shaft is connected at one end to a vibratory mechanism, and is connected at the other end within the chamber to a piston. The piston has a shape which closely conforms the shape of the chamber, such that due to the operation of the vibrating mechanism, the piston can slidably oscillate within the chamber. The oscillation of the piston within the chamber causes a slight vacuum to be created in the chamber as the chamber moves in a first direction past the inlet, consequently drawing fluid into the chamber through the inlet for the chamber. Movement of the piston in the opposite direction then closes the inlet and urges the fluid drawn into the chamber through the outlet of the chamber as the piston moves through the chamber towards the outlet. The size of the piston conforms closely to interior shape of the chamber such that the piston does not allow any fluid to flow between the piston and the chamber. Also, the piston and the chamber are formed of materials that are self-lubricating to enable them to move freely with respect to one another, and that are highly resistant to any damaging or corrosive properties of the fluids being dispensed by the pump such that the piston and chamber can be utilized to dispense a wide variety of fluids. 
         [0007]    According to another aspect of the present invention, the chamber can include multiple inlets in order to increase the amount of fluid being drawn into the chamber during the operation of the pump. Also, the outlet for the chamber can be disposed in a nozzle secured to the chamber to enable the pattern or amount of fluid being dispensed from the chamber to be varied as desired. 
         [0008]    According to still another aspect of the present invention, the chamber and piston contained within the chamber can be formed as an attachment that is attachable to an existing vibratory motor or similar device in order to enable the device to be converted to a piston pumping device. 
         [0009]    Numerous additional advantages, aspects and features of the present invention will be made apparent from the following detailed description taken together with the drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The drawings illustrate the best mode currently contemplated of practicing the present invention. 
           [0011]    In the drawings: 
           [0012]      FIG. 1  is a cross-sectional view of the vibratory piston pumping mechanism of the present invention; and 
           [0013]      FIG. 2  is a cross-sectional view of an alternative embodiment of the mechanism of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    With reference now to the drawing figures in which like reference numerals designate like parts throughout the disclosure, a pump constructed according present invention is indicated generally at  100  in  FIG. 1 . The pump  100  includes a casing  1  that can be formed of any suitable rigid and liquid-impervious material. The casing  1  encloses a motor  3  that is secured to the interior of the casing  1 . The motor  3  is in turn connected via a shaft  2  to a rotating member  4  that is rotated in response to the rotation of the shaft  2  by the motor  3 . The power for the motor  3  is supplied by a pair of batteries  20  positioned within receptacles  21  located within the casing  1  in preferred embodiment. Alternatively, the motor  3  may also be powered by other suitable means, such as a plug (not shown) connected to the motor  3  at one end and insertable into an electrical outlet at the opposite end, among others. 
         [0015]    The rotating member  4  is connected via an extension  5  and connectors  105  to a bracket  6  disposed at one end of a piston rod  7 . The bracket  6  includes a pivot pin  8  to which the extension  5  is connected in order to enable the bracket  6  to rotate with respect to the extension  5  when the rotating member  4  and motor  3  are operating. The piston shaft  7  extends through a shaft opening  8  into a chamber  9 . The shaft opening  8  is located within a shaft collar  108  that can be formed integrally as part of the chamber  9  or as a separate part that is subsequently fixedly attached to the chamber  9 . The chamber  9 , and preferably the shaft collar  8 , is formed from a generally rigid material that is highly resistant to any harsh fluids that may potentially be dispersed by the pump, such as a hard plastic, and defines an interior  10  that is in fluid communication with a pair of inlets  11  and an outlet  12 . The inlets  11  can be integrally formed with the chamber  9 , or can be formed separately from the chamber  9  of a material similar to the chamber  9 , as desired. Each inlet  11  is attached to a tube  13  formed of a rigid or flexible material which extends outwardly from the inlet  11  and out of the casing  1  through a collar  117  located on the casing  1 . The collar  117  is releasably engaged, and preferably threadedly engaged, with a bottle  18  having any desired configuration. The tubes  13  extend into the bottle  18  to approximately the bottom of the bottle  18 , such that the tubes  13  are normally always positioned beneath the level of a fluid or liquid  19  disposed within the bottle  18 . 
         [0016]    The outlet  12  of the chamber  9  can be formed integrally with the casing  9 , but preferably is formed within a nozzle  112  that can have any desired configuration for dispensing the fluid  19  out of the casing  1  in a desired manner, such as by incorporating a number of different outlets  12  each in fluid communication with the interior  10  of the chamber  9 . However, in a particularly preferred embodiment, the outlet  12  includes an inner portion  15  that has a tapering cross section as the inner portion extends away from the chamber interior  10 , and an outer portion  16  that has a generally circular cross section. Thus, fluid directed out of the chamber  9  is collected in the inner section  15  and compressed as it moves to the outer section  16  such that a pressurized stream of the fluid  19  is dispensed out of the outlet  12 . The nozzle  112 , similarly to the shaft collar  108 , is formed of a highly damage-resistant material that can be integrally or separately formed from the chamber  9 . 
         [0017]    The fluid  19  is moved through the outlet  12  in the nozzle  112  by the oscillating movement of a piston  17  attached to the piston shaft  7  opposite the bracket  6 . The piston  17  has a cross-sectional shape corresponding to the shape of the interior  10  defined within the chamber  9  such that the movement of the piston  17  effectively pushes any fluid  19  located within the interior  10  of the chamber  9  between the piston  17  and the nozzle  112  out through the outlet  12 . Preferably, the chamber  9  has a generally circular cross-section with the piston  17  also having a generally circular cross-section with a diameter slightly less than that of the chamber interior  10 . The difference in the diameter between the chamber interior  10  and the piston  17  is small, i.e., small enough to prevent any significant amount of fluid from flowing between the piston  17  and the chamber  9 . Thus, while the piston  17  can move freely within the chamber interior  10 , the tight tolerances between the piston  17  and the chamber interior  10 , effectively prevent any significant amount of fluid  19  from flowing between the piston  17  and the chamber  9 . The ability of the piston  17  to move freely within the chamber  9  with these tight tolerances can be assisted by forming the piston  17  and or the chamber  9 , or by applying a coating  120  to the chamber interior  10  with a self-lubricating material that enables the piston  17  to slide more easily along the chamber interior  10 . Different types of material that are suitable for this purpose include various plastics, plastic-rubber composites, and synthetic rubbers such as alkyds, polyurethanes, silicones, polyacrylics, and fluoropolymer resins, such as Teflon®, among other suitable materials. 
         [0018]    In operation, after the casing  1  is effectively attached to the bottle  18  utilizing the collar  117 , a switch  21  disposed on the casing  1  is activated which supplies power from the batteries  20  to the motor  3 . The operation of the motor  3  results in a rotation of the shaft  2  and the rotatable member  4 , consequently causing the shaft  7  and piston  17  to oscillate with respect to the chamber  9 . As the piston  17  is drawn by the shaft  7  away from the outlet  12 , the movement of the piston  17  creates a vacuum within the chamber interior  10 , thereby drawing liquid  19  from within the bottle  18  through the tubes  13  and into the chamber  9  through the inlets  11 . When the piston  17  begins moving forwardly through the chamber  9  towards the outlet  12 , the piston  17  pushes all of the fluid  19  drawn into the chamber  9  and positioned between the piston  17  and the outlet  12  towards the outlet  12 , consequently dispensing the fluid  19  through the outlet  12  in the desired manner. Due to the tight tolerance between the piston  17  and the chamber  9 , the fluid  19  does not pass between the piston  17  and the chamber  9  as the piston  17  moves towards the outlet to ensure the fluid is dispensed from within the chamber  9 . After the piston  17  contacts the nozzle  112 , the piston  17  then is withdrawn or moved away from the outlet  12  by the further rotation of the rotatable member  4  to move or draw more fluid  19  into the chamber  9  through the inlets  11  in order to repeat the cycle. 
         [0019]    In a preferred embodiment, to vary the volume of fluid  19  dispensed by the pump  100 , the motor  3  can be operated to cause the piston  17  to oscillate within the chamber  9  with in a frequency range of between about 100 to 10,000 cycles per second. The various types of motors  3  which can be utilized in this invention are those which are capable of oscillating the piston  17  within the chamber  9  within this frequency range, including electric motors, piezoelectric motors and other suitable types of motors. 
         [0020]    Referring now to  FIG. 2 , in an alternative embodiment for the pump  100 , the chamber  9  can be positioned concentrically within a secondary chamber or enclosure  24 . The enclosure  24  forms a space  26  around the chamber  9  and includes an inlet tube  28  extending outwardly from and preferably integrally formed with the enclosure  24 . Also, the chamber  9  is formed with a number of inlets  11 ′ which are formed as openings or bores extending through the exterior of the chamber  9 . The operation of this embodiment is highly similar to the embodiment in  FIG. 1  because the fluid  19  is drawn upwardly through the inlet tube  28  into the enclosure  24  and through the openings  11 ′ into the chamber  9  for direction through the outlet  12  by the oscillating piston  17 . However, due to the construction of this embodiment without an outer casing  1 , the chamber  9  can be utilized as an attachment for an existing oscillating mechanism (not shown) to which the shaft  7  and piston  17  can be releasably attached in order to enable the mechanism to function as a pump  100 . 
         [0021]    Various alternatives are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.