Abstract:
In one general aspect, a flow control valve includes: a housing including a tubular wall surrounding an interior passage, and a flow control section in which the tubular wall includes a conical inner wall surface; a protrusion disposed on an exterior surface of the tubular wall at the flow control section; a sealing member disposed in the housing and configured to be selectively moved to a sealing position in which the sealing member engages the conical inner wall surface to restrict flow of a fluid through the interior passage; and a recess disposed the conical inner wall surface and configured to allow the fluid to flow past the sealing member through the recess when the sealing member is in the sealing position, wherein the recess and the protrusion are radially aligned on the tubular wall.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 USC 119(e) of U.S. Provisional Application No. 62/235,125 filed on Sep. 30, 2015, the entire disclosure of which is incorporated herein by reference for all purposes. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    The following description generally relates to flow control valves. 
         [0004]    2. Description of Related Art 
         [0005]    Flow control valves are used in many applications in which it is desirable to control the flow of fluid in a device or system. Examples of flow control valves are directional check valves, flow restricting valves and dispensing valves. 
         [0006]    A directional check valve is biased in a closed configuration in which a sealing member prevents fluid flow through the valve, and the sealing member is moveable to place the valve in an open configuration in which the sealing member permits fluid flow through the valve in only a desired direction. More specifically, sufficient pressure from fluid flowing in the desired direction forces the sealing member to move to open the valve, allowing the fluid to flow through the valve in the desired direction. Backward fluid flow (“backflow”) in a direction opposite the desired direction while the valve is open forces the sealing member to move to close the valve. 
         [0007]    One type of flow restricting valve allows fluid to flow therethrough in two opposing directions. The valve is biased in a closed configuration in which a sealing member permits a relatively small amount of backflow through the valve. The sealing member is moveable to place the valve in an open configuration in which a relatively large amount of fluid flow is permitted through the valve in a desired direction. Backflow opposite the desired direction while the valve is in the open configuration forces the sealing member to move to close the valve. The controlled backflow allowed through the valve while the valve is in the closed configuration may prevent fluid from being trapped in an area forward of the valve for extended periods of time when there is no fluid flow in the forward direction. 
         [0008]    A dispensing valve includes a control mechanism for selectively opening the valve. The valve may be biased in a closed position in which a sealing member prevents fluid flow through the valve. The control mechanism may be operated to move the sealing member to open the valve and allow fluid flow through the valve in a desired direction. 
         [0009]    The various flow control valves described above are often complex and expensive to manufacture. For example, some flow control valves may open and/or close too slowly, or may have sealing members that do not provide consistent, reliable sealing to prevent or restrict fluid flow. 
         [0010]    Accordingly, it is desirable to provide flow control valves that are inexpensive to manufacture and provide improved performance. 
       SUMMARY 
       [0011]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
         [0012]    In one general aspect, a flow control valve includes: a housing including a tubular wall surrounding an interior passage, and a flow control section in which the tubular wall includes a conical inner wall surface; a protrusion disposed on an exterior surface of the tubular wall at the flow control section; a sealing member disposed in the housing and configured to be selectively moved to a sealing position in which the sealing member engages the conical inner wall surface to restrict flow of a fluid through the interior passage; and a recess disposed the conical inner wall surface and configured to allow the fluid to flow past the sealing member through the recess when the sealing member is in the sealing position, wherein the recess and the protrusion are radially aligned on the tubular wall. 
         [0013]    The housing may be formed of plastic. 
         [0014]    The sealing member may include a body including an internal cavity. 
         [0015]    The internal cavity may contain a gas. 
         [0016]    In another general aspect, a method of manufacturing a flow control valve housing includes flowing a fluid material into a mold to form a housing including a tubular wall surrounding an interior passage, and a flow control section in which the tubular wall includes a conical inner wall surface, wherein the tubular wall has a predetermined radial thickness in the flow control section. The method further includes flowing the fluid material into the mold to form a protrusion disposed on an external surface of the tubular wall at the flow control section, wherein the protrusion extends in a radial direction with respect to a central axis of the tubular wall and has a predetermined thickness in a direction perpendicular to the radial direction, and cooling and solidifying the fluid material in the mold to cause a recess to form on the inner wall surface in a position radially aligned with the protrusion on the tubular wall. 
         [0017]    The recess may have a radial depth that is a predetermined function of the radial wall thickness and the protrusion thickness. 
         [0018]    In another general aspect, a valve includes: a housing including a tubular wall surrounding an interior passage, and a flow control section in which the tubular wall includes a conical inner wall surface; and a sealing member including a body including an interior cavity, wherein the sealing member is disposed in the housing and is configured to be selectively moved to a sealing position in which the body engages the conical inner wall surface to restrict flow of a fluid through the housing. 
         [0019]    The body may further include a hemispherical tip configured to engage the conical inner wall surface. 
         [0020]    The interior cavity may contain a gas. 
         [0021]    The valve may further include a biasing member configured to bias the sealing member in the sealing position. 
         [0022]    The valve may further include a control mechanism, wherein: the control mechanism includes a body member, and a rod connected to the body member and configured to engage the sealing member; and the rod is configured to move the sealing member from the sealing position to an open position allowing flow of the fluid through the housing, in response to the body member being moved in a direction opposite a direction of a biasing force applied by the biasing member. 
         [0023]    Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1A  is a perspective view of a flow control valve according to an example. 
           [0025]      FIG. 1B  is a top view of the flow control valve of  FIG. 1A . 
           [0026]      FIG. 1C  is a side cross-sectional view taken along line A-A of  FIG. 1B . 
           [0027]      FIG. 1D  is a bottom cross-sectional view taken along line B-B of  FIG. 1C . 
           [0028]      FIG. 1E  is an enlarged view of a portion A of  FIG. 1D . 
           [0029]      FIG. 2  is a bottom cross-sectional view of a housing of the flow control valve of  FIG. 1A . 
           [0030]      FIG. 3  is a side cross-sectional view of a flow control valve according to another example. 
           [0031]      FIG. 4  is a side cross-sectional view of a flow control valve according to yet another example. 
       
    
    
       [0032]    Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. 
       DETAILED DESCRIPTION 
       [0033]    The following description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent to those of ordinary skill in the art. The sequences of operations described herein are merely examples, and are not limited to those set forth herein, but may be changed as will be apparent to one of ordinary skill in the art, with the exception of operations necessarily occurring in a certain order. Also, descriptions of well-known functions and constructions that are well known to one of ordinary skill in the art may be omitted for increased clarity and conciseness. 
         [0034]    The features described herein may be embodied in different forms, and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete, and will convey the full scope of the disclosure to one of ordinary skill in the art. 
         [0035]      FIGS. 1A-1E  show a flow control valve  100  according to an example. The flow control valve  100  may be considered to be a flow restricting valve that, when in a closed configuration, is configured to allow a predetermined amount of backflow of fluid. That is, the flow control valve  100 , when closed, is configured to allow a small amount of fluid flow in the backward direction R opposite the forward direction F of fluid flow allowed when the valve is open. 
         [0036]    As shown in  FIGS. 1A-1E , the flow control valve  100  includes a hollow housing  110  and a plunger or sealing member  150  configured to reciprocate within the housing  110  to control the flow of the fluid through the housing  110 . The housing  110  includes a generally tubular wall  111 , and includes a first end  112  and a second end  114 . The tubular wall  111  surrounds an interior passage  116  extending from the first end  112  to the second end  114 , and includes a flow control section  118  between the first end  112  and the second end  114 . The flow control section  118  includes a conical inner wall surface  120  in the interior of the housing  110 . The conical inner wall surface  120  provides a conical sealing surface for the sealing member  150 . As shown in  FIGS. 1A, 1B and 1D , an external protrusion  124  is formed on an external surface of the tubular wall  111  at the flow control section  118  and extends from the external surface of the tubular wall  111  in a radial direction X with respect to a central axis C of the passage  116 . As shown in  FIGS. 10-1E , a sink or recess  122  is formed in the conical inner wall surface  120 . As will be explained in detail later, the protrusion  124  and the sink or recess  122  are radially aligned with each other on opposing sides of the tubular wall  111 . 
         [0037]    Referring to  FIG. 1B , the sealing member  150  is a vial-shaped body including a hemispherical tip  152  for engaging the conical inner wall surface  120 . The sealing member  150  has an interior cavity  160  which may be filled with a gas, such as air, to improve buoyancy. The sealing member  150  may be constructed of a plastic or another polymer material, preferably of low density. 
         [0038]    The sealing member  150  is biased in a sealing position in which the hemispherical tip  152  engages the conical inner wall surface  120  and forms a partial seal in the interior passage  116 . When the sealing member  150  is in the sealing position, the flow control valve  100  is considered to be in a closed configuration. When a sufficient amount of fluid flow in the forward direction F from the first end  112  to the second end  114  is present in the interior passage  116 , sealing member  150  is forced to move out of the sealing position into an open position in the direction F. The flow control valve  100  is thereby placed in an open configuration in which fluid flow is permitted through the interior passage  116  in the direction F. After fluid flow in the forward direction F ceases, the sealing member  150  returns to the sealing position. 
         [0039]    As shown in  FIGS. 1C-1E , when the sealing member  150  is in the sealing position, the seal between the sealing member  150  and the conical inner wall surface  120  is not completely fluid-tight, since the recess  122  forms a gap  123  between the sealing member  150  and the conical inner wall surface  120 . Thus, when the sealing member  150  in the sealing position, the flow control valve  100  is considered to be closed, and heavily restricts but does not completely block fluid flow in the backward direction R from the second end  114  to the first end  112 . That is, when the flow control valve  100  is closed, a small amount of fluid flow, relative to the amount of fluid flow permitted in the forward direction F when the valve is open, is permitted in the backward direction R. Thus, fluid that present in the interior passage  116  forward of the area at which the sealing member  150  engages the conical inner wall surface  120  is permitted to flow backward through the gap  123  in the direction R at a predetermined rate. As will be described later in detail, the rate at which fluid is allowed to flow in the direction R is permitted to flow in the direction R is determined by the size of the gap  123 , which is a function of the size of the recess  122 . 
         [0040]    The combination of a low-density material construction and the gas-filled interior cavity  160  makes the sealing member  150  highly buoyant, and therefore enables rapid movement of the sealing member  70  from the sealing position to the open position for improved responsiveness of the flow control valve  100 . 
         [0041]    Referring to  FIG. 2 , the housing  110  is a substantially tubular member having a radial wall thickness “W” in the flow control section  118 . The protrusion  124  has a radial length L in the radial direction X, and a thickness “T” in a direction perpendicular to the radial direction X. The recess  122  has a radial depth “S” in the radial direction X, and the radial depth S may be selected to provide the desired fluid flow rate (backflow rate) in the direction R. The backflow rate for the will increase as S increases. The housing  110  may be constructed of plastic, polymer material, or other material with suitable performance characteristics (such as shrinkage properties), for example, and may be manufactured by a molding process, as described below, such that W, T and S may be precisely determined. 
         [0042]    The housing  110  may be manufactured by injecting or flowing a fluid material, such as a liquid polymer, liquid metal or other suitable material, into a mold shaped to provide the desired wall thickness W and protrusion thickness T. More specifically, according to an embodiment, a method of molding the housing  110  includes flowing a fluid material into a first section of a mold that is configured to form the housing  110  including the tubular wall  111  having the flow control section  118 , and flowing the fluid material into a second section of the mold that is configured to form the protrusion  124  on the external surface of the flow control section  118 . The first section of the mold may be configured to form the flow control section  118  to have the predetermined radial wall thickness W, and the second section of the mold may be configured to form the protrusion  124  to have the predetermined protrusion thickness T. The method further includes cooling and solidifying the fluid material in the mold to form the housing  110 . The cooling and solidifying of the fluid material causes shrinkage of the inner wall surface in the area opposite to the protrusion  124  and thereby forms the recess  122  in the area opposite to the protrusion  124 , such that the recess  122  and the protrusion  124  are radially aligned. The size of the recess  122  is a function of the radial wall thickness W, and the size and shape of the protrusion  124 . More specifically, the radial depth S of the recess  122  is a predetermined function of the radial wall thickness W and the protrusion thickness T. Thus, the mold can be designed to provide a protrusion thickness T and wall thickness W that will reliably produce the desired radial depth S of the recess through shrinkage of the inner wall surface during the molding process. 
         [0043]      FIG. 3  shows a flow control valve  200  according to another example. The flow control valve  200  may be considered to be a directional check valve. The flow control valve  200  is similar to the valve  100  of  FIGS. 1A-1E , except that the flow control valve  200  includes a housing  210 . The housing  210  is similar to the housing  110  of the previous example, with the exception that the housing  210  includes a tubular wall  211  with a flow control section  218  that lacks the protrusion  124  of the valve  100 . 
         [0044]    The flow control section  218  includes a conical inner wall surface  220  that provides a conical sealing surface for the sealing member  150 . The conical inner wall surface  220  does not include the recess  122  of the conical inner wall surface  120  of the previous embodiment, and therefore forms a flat, uniform surface for engaging the sealing member  150 . Thus, contrary to the valve of  FIGS. 1A-1E , when the flow control valve  200  is in a closed configuration in which the hemispherical tip  152  of the sealing member  150  engages the conical inner wall surface  220 , a complete seal is formed between the sealing member  150  and the conical sealing surface  220 . Accordingly, the flow control valve  200  allows fluid flow only in the forward direction F when the flow control valve  200  is open, and blocks fluid flow in both the forward direction F and the backward direction R when the flow control valve  200  is closed. 
         [0045]      FIG. 4  shows a flow control valve  300  according to another example. The flow control valve  300  is a dispensing valve that can be selectively placed in an open configuration to permit fluid flow only in the forward direction F, and selectively placed in a closed configuration to prevent fluid flow in the forward direction F and the backward direction R. 
         [0046]    Referring to  FIG. 4 , the flow control valve  300  includes a housing  310 , the sealing member  150  configured to reciprocate within the housing  310  to control the flow of the fluid through the housing  310 , and a control mechanism  330  operable to move the sealing member  150  to place the flow control valve  300  in an open configuration. The housing  310  includes a generally tubular wall  311 , a first end  312 , and a second end  314 . The tubular wall  311  surrounds an interior passage  316  and includes a flow control section  318  between the first end  112  and the second end  114 . The flow control section  318  includes a conical inner wall surface  320  in the interior of the housing  310 . The conical inner wall surface  320  provides a conical sealing surface for the sealing member  150 . 
         [0047]    The flow control valve  300  may be connected to a fluid supply  10  at the first end  312  of the control valve  300 . Because the sealing member  150  is highly buoyant, pressure from fluid in the fluid reservoir  10  and around the sealing member  150  in the interior passage  316  biases the flow control valve  300  in a closed configuration. That is, the sealing member  150  is biased in a sealing position in which the hemispherical tip  152  of the sealing member  150  engages the conical inner wall surface  320  to form a complete seal between the sealing member  150  and the conical inner wall surface  320 , thereby preventing fluid flow in the forward direction F and the backward direction R. 
         [0048]    To provide the sealing member  150  with a greater bias force in the sealing position and to provide a faster return of the sealing member  150  to the sealing position from an open position, a biasing spring  352  may be provided in the interior passage  316  in engagement with the sealing member  150 . The biasing spring  352  may be attached to an end of the sealing member  150  opposite the hemispherical tip  152 , or formed integrally with the sealing member  150  at the end of the sealing member  150  opposite the hemispherical tip  152 . 
         [0049]    The control mechanism  330  is attached to the housing  310  at the second end  314  of the housing  310 . The control mechanism  330  includes a body member  332  configured to slide over the housing  310 , a rod  334  connected to the body member  332  and configured to reciprocate in the interior passage  316 , and a fluid channel  336  in fluid communication with the interior passage  316 , and extending through the body member  332  and around the rod  334 . The rod  334  is configured to engage the hemispherical tip  152  of the sealing member  150 . 
         [0050]    When the body member  332  is depressed in an operating direction D 1 , the body member  332  slides over the housing  310  in the direction D 1  and the rod  334  moves the sealing member  150  to the open position out of contact with the conical sealing surface  320 . The flow control valve  300  is thereby placed in the open configuration, allowing fluid flow only in the forward direction F from the fluid supply  10  to the interior passage  316  and the fluid channel  336 . When the body member  332  is released and allowed to return to its rest position in the direction D 2  opposite the operating direction D 1 , the rod  334  moves in the direction D 2  and allows the sealing member  150  to return to the sealing position under the biasing force provided by fluid pressure (and, optionally, the biasing spring  352 ), thereby placing the flow control valve  300  in the closed configuration. 
         [0051]    The flow control valves disclosed herein provide precise control of fluid flow and fast transitions between open and closed configurations. Additionally, the disclosed flow control valves may be manufactured at relatively low cost. 
         [0052]    Words describing relative spatial relationships, such as “forward”, “backward”, “top” and “bottom” may be used to conveniently describing spatial relationships of one device or elements with other devices or elements. Such words are to be interpreted as encompassing a device oriented as illustrated in the drawings, and in other orientations in use or operation. For example, an example in which an element as moving forward also encompasses the element moving backward when the orientation of the device is reversed in use or operation. 
         [0053]    While this disclosure includes specific examples, it will be apparent to one of ordinary skill in the art that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples describing herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the describing techniques are performed in a different order, and/or if components in a describing system or device are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.