Abstract:
The present application discloses a device and an exemplary system utilizing the device for precise low pressure/high flow capability pumps. One non-limiting example of such a pump is used in the medical field and operates at approximately 0.5 cubic feet per minute at 1.5 Psi. The device of the present application regulates pressure from such a pressure pump to an output chamber by exhausting excess pressure to atmosphere once the pressure to the output chamber reaches a desired adjustable level.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority of U.S. Provisional Application No. 61/430,377, filed Jan. 6, 2011, the content of which is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    The present application is directed to the field of pressure regulation. More specifically, the present application is directed to the field of back pressure regulation in low pressure/high flow systems. 
       BACKGROUND 
       [0003]    Existing regulating devices and systems utilized in low pressure/high flow systems fail to maintain a stable setpoint throughout a full range of a low pressure pump, and further do not include an internal convoluted diaphragm that does not vibrate during operation. These shortcomings make for current devices that are noisy and unstable. Such devices are sometimes referred to as back-pressure regulators. Such devices exist for higher pressure applications, but there are no known devices that work precisely at low pressure/high flow conditions. 
       SUMMARY 
       [0004]    The present application discloses a device and an exemplary system utilizing the device for precise low pressure/high flow capability pumps. One non-limiting example of such a pump is used in the medical field and operates at approximately 0.5 cubic feet per minute at 1.5 Psi. 
         [0005]    The device of the present application regulates pressure from such a pressure pump to an output chamber by exhausting excess pressure to atmosphere once the pressure to the output chamber reaches a desired adjustable level. 
         [0006]    In one aspect of the present application a pressure regulator device includes a base portion having a supply port and a convoluted diaphragm having a u-shaped portion at an attachment point to the base portion, the convoluted diaphragm secured to seal the supply port from an exhaust chamber in the base portion with a bias force from an adjustment spring, the convoluted diaphragm further moving in a path opposite the bias in response to a predetermined pressure level at the supply port, wherein pressure is released through the exhaust chamber to an exhaust opening in the base when the predetermined pressure level is reached, and a spring cavity housing secured to the base portion and housing the adjustment spring, the spring cavity including a reference to atmosphere opening in order to maintain atmospheric pressure in the spring cavity housing. 
         [0007]    In another aspect of the present application a pressure regulator device includes a base portion having a supply port and a convoluted diaphragm, the convoluted diaphragm secured to seal the supply port from an exhaust chamber in the base portion with a bias force from an adjustment spring, the convoluted diaphragm further moving in a path opposite the bias in response to a predetermined pressure level at the supply port, wherein pressure is released through the exhaust chamber to an exhaust opening in the base, and a spring cavity housing secured to the base portion and housing the adjustment spring, the spring cavity including a reference to atmosphere opening in order to maintain atmospheric pressure in the spring cavity housing. 
         [0008]    In another aspect of the present application a pressure regulator device includes a base portion having a supply port and a convoluted diaphragm having a u-shaped portion at an attachment point to the base portion, the convoluted diaphragm secured to seal the supply port from an exhaust chamber in the base portion with a bias force from an adjustment spring, the convoluted diaphragm further moving in a path opposite the bias in response to a predetermined pressure level at the supply port, wherein pressure is released through the exhaust chamber to an exhaust opening in the base when the predetermined pressure level is reached, and a spring cavity housing secured to the base portion and housing the adjustment spring. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0009]      FIG. 1  illustrates a schematic diagram of an embodiment of a system of the present application. 
           [0010]      FIG. 2  illustrates a section view of an embodiment of the device of the present application, illustrating the device in a fully open position. 
           [0011]      FIG. 3  illustrates a section view of an embodiment of the device of the present application, illustrating the device in a closed position. 
           [0012]      FIG. 4  illustrates a bottom view of an embodiment of the device of the present application. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    In the present description, certain terms have been used for brevity, clearness and understanding. No unnecessary limitations are to be applied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The different systems and methods described herein may be used alone or in combination with other systems and methods. Various equivalents, alternatives and modifications are possible within the scope of the appended claims. Each limitation in the appended claims is intended to invoke interpretation under 35 U.S.C. §112, sixth paragraph, only if the terms “means for” or “step for” are explicitly recited in the respective limitation. 
         [0014]    Referring to  FIG. 1 , in an exemplary system  40  of the present application a pressure pump  42  supplies pressurized air to an output chamber  46  through a system air line  48 . The pressure that is supplied to the output chamber  46  typically needs to be regulated down to a desired and/or required setpoint. A standard in-line, pressure regulator (not shown) of the prior art would reduce the airflow to the output chamber  46 , thus dramatically increasing the amount of time that it would take to fill the output chamber  46 . 
         [0015]    In this exemplary embodiment, the device  10  is connected in a T configuration or “tee&#39;d” off the system air line  48  from the pressure pump  42  to the output chamber  46  as shown. This device  10  allows the pressurized air to flow from the pressure pump  42  to the output chamber  46  until the desired and/or required pressure setting of the output chamber  46  is reached, and then the excess supply of air delivered from the pressure pump  42  is exhausted out of the device  10  to atmosphere through the supply exhaust opening  34  ( FIG. 2 ). 
         [0016]    Referring to  FIGS. 2 and 3  simultaneously, a section view of the device  10  of the present application is illustrated. The device  10  includes a spring cavity housing  37  and a base portion  39 . The spring cavity housing  37  houses the adjustment spring  18  and the mechanism for adjusting the adjustment spring  18 , including the adjustment screw  12 , the o-ring  14  and the adjustment nut  16 . In operation, a user utilizes a tool in order to rotate the adjustment screw  12  that in turn compresses the adjustment spring  18  between the adjustment nut  16  and a spring guide  22 . The spring guide  22  is in direct contact with the convoluted diaphragm  28 , and when the supply port  36  has no pressure, or pressure below the set level, the convoluted diaphragm  28  covers the supply port  36  and seals the supply port  36  by maintaining contact with a sealing ring  32  as shown in  FIG. 3 . The convoluted diaphragm  28  is convoluted due to a u-shaped portion  30  about the circumference of the convoluted diaphragm  28 , and defined on one side by an attachment point to the base portion  39 . 
         [0017]    Still referring to  FIGS. 2 and 3  simultaneously, as stated previously, the convoluted diaphragm  28  seals an exhaust chamber  38  from the supply port  36  when the pressure at the supply port  36  is below the set limit. Once the pressure at the supply port  36  exceeds the limit, then the convoluted diaphragm  28  is pushed against the bias of the compressed adjustment spring  18  and allows air to flow from the supply port  36  through the exhaust chamber  38  and out through a supply exhaust opening  34 . Once again, a user may adjust the predetermined pressure set point by utilizing a tool on the adjustment screw  12 . In the illustrated embodiment, the user may use a flathead screwdriver to adjust the position of the adjustment screw  12 . However, any other screwdriver, alien wrench, or other tool format able to provide the appropriate torque on the adjustment screw  12  may be utilized. 
         [0018]    Referring to  FIGS. 1 and 2  simultaneously, in operation the device  10  is shown in its “fully open” position, which allows the maximum amount of airflow through the device  10 , from the supply port  36  to the supply exhaust opening  34 . In this fully open position, the pressure pump  42  delivers the lowest amount of pressure possible to the output chamber  46 , as the convoluted diaphragm  28  is not creating a seal with the sealing ring  32  to close the supply port  36 . As the adjustment spring  18  is compressed by adjustment of the adjustment screw  12  or by loss of pressure in the system  40 , it forces the convoluted diaphragm  28  down until it covers the sealing ring  32  ( FIG. 3 ). Referring now to  FIGS. 1 and 3  simultaneously, this blocks the path of air out of the device  10 , which allows all of the airflow to be sent to the output chamber  46  via the system air line  48 . Once the pressure approaches its desired setting, the convoluted diaphragm  28  is pushed up, away from the sealing ring  32  and allows some of the air from the pressure pump  42  to be exhausted to atmosphere through the supply exhaust opening  34 . The convoluted diaphragm  28  will move up until equilibrium is reached between the force of the compressed adjustment spring  28  pushing in one direction and the force of the pressurized air in the opposite direction, as shown in  FIG. 2 . 
         [0019]    Referring again to  FIGS. 1 and 3  simultaneously, a convoluted diaphragm  28  is used in this device  10  to allow the convoluted diaphragm  28  to move into its desired position more readily than a flat diaphragm (not shown), thus giving the device  10  more precision. The U-shaped portions  30  of the convoluted diaphragm  28  allow for an amount of slack in the convoluted diaphragm  28 . This slack created by the U-shaped portions  30  allows for greater ease of movement of the convoluted diaphragm  28  between the positions shown in  FIGS. 2 and 3 , but also causes some vibration in the convoluted diaphragm  28 . In order to remedy this vibration caused by having a convoluted diaphragm  28 , the referenced atmosphere opening  20  must have an appropriate position and sizing on the spring cavity housing  37 . Creating such a referenced atmosphere opening  20  with appropriate sizing and placement on the housing  37  will eliminate vibration of the convoluted diaphragm  28 . 
         [0020]    It should also be noted here that the position of the supply port  36 , i.e., the supply port  36  being centered with respect to the convoluted diaphragm  28 , and positioning the supply exhaust opening  34  to the side of the supply port  36 , allows for a more uniform air flow from the supply port  36  to the convoluted diaphragm  28 , also assisting in eliminating vibration of the convoluted diaphragm  28 . As will be discussed below, an embodiment including a plurality of exhaust openings  34  ( FIG. 4 ) further allows for a more uniform air flow from the supply port  36  to the convoluted diaphragm  28 . 
         [0021]    Many times during this “equilibrium” state, prior art diaphragms tend to vibrate and not only cause the setpoint to vary, but also create an audible noise. As discussed above, a properly sized and located reference to atmosphere opening  20  in the device  10  assists in further eliminating this vibration. When this opening  20  is properly sized and located, it acts as a “muffler” to dampen out any natural frequency that would otherwise occur and eliminate any residual vibration in the convoluted diaphragm  28 . This correction for any residual vibrating in the convoluted diaphragm  28  is what makes the device extremely accurate in low pressure/high flow applications. 
         [0022]    The reference to atmosphere opening  20  on the side end of the device  10  ensures that atmospheric pressure is maintained in the cavity housing  37  of the adjustment spring  18 . This ensures a more accurate device  10 , in that without a reference to atmosphere opening  20 , air pressure would vary in the cavity housing  37  of the adjustment spring  18  when the convoluted diaphragm  28  changed positions. With the reference to atmosphere opening  20 , the adjustment spring  18  is the only element creating a bias against the convoluted diaphragm  28 . This allows the pressure to be adjusted by adjusting the compression on the adjustment spring  18  with the adjustment screw  12  only. 
         [0023]    Referring back to  FIG. 1 , a pressure gauge  44  is also connected to the system air line  48  of the system  40  in a T configuration in order to properly calibrate and/or adjust the device  10 . The pressure gauge  44  allows a user of the system  40  to measure and record the pressure in the system  40  while adjusting the adjustment screw  12  ( FIGS. 2 and 3 ) of the device  10 . Additional embodiments (not shown) may include a device  10  that has an integrated pressure gauge  44  with two “T” lines running from the device  10  to the system air line  48 , or a pressure gauge  44  configured in another component of the system  40 . 
         [0024]    Referring to  FIG. 4 , a device of the present application is illustrated from a bottom perspective. Here, the bottom of the base portion  39  of the device  10  is illustrated including the supply port  36  and a plurality of exhaust openings  34 . As discussed above, the device  10  may include a single exhaust opening  34 , or any number of exhaust openings  34  configured in the base portion. It should be noted that further embodiments may include any number of exhaust openings in a variety of patterns on the bottom of the device  10  or fashioned into other surfaces of the base portion  39 . In the illustrated embodiment of  FIG. 4 , three exhaust openings  34  are configured 120 degrees apart from each other relative to the supply port  36 , and the exhaust openings  34  are equidistant to the supply port  36 . This configuration causes a more uniform flow of air from the supply port  36  through the exhaust chamber  38  and out of the device  10  through the exhaust openings  34 . This uniform flow assists in eliminating the vibration of the convoluted diaphragm  28 . 
         [0025]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.