Patent Publication Number: US-2023160487-A1

Title: Check valve with flash seal

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 17/518,877, entitled “CHECK VALVE WITH FLASH SEAL,” filed Nov. 4, 2021, which is a continuation application of U.S. patent application Ser. No. 16/869,428, entitled “CHECK VALVE WITH FLASH SEAL,” filed May 7, 2020, which issued on Dec. 7, 2021, as U.S. Pat. No. 11,193,601, all of which are herein incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     Check valves are used in the medical field in devices for controlling fluid flow to a patient, such as for fluid flow from an intravenous (IV) gravity or pump set. Typical check valves are susceptible to low flow leakage if particulate becomes caught between the elastomeric seal and the seal bead. Having dual seal beads provides challenges because the seal beads need to be exactly the same height in order to eliminate a possible gap that would allow leakage. It is desirable to provide a medical fluid flow check valve that prevents low flow leakage, thus improving safety and reducing risks. 
     SUMMARY 
     The present disclosure provides medical fluid flow check valves having dual sealing rings. 
     One or more embodiments provide a check valve assembly including an inlet body comprising a fluid inlet, a first seal bead and a second seal bead, an outlet body comprising a fluid outlet, and a seal comprising inner and outer rings, wherein, in a fully sealed position of the check valve assembly, the inner ring is configured to engage with the first seal bead and the outer ring is configured to engage with the second seal bead. 
     One or more embodiments provide an intravenous (IV) set including a fluid inlet tube, a fluid outlet tube, and a check valve assembly. The check valve assembly including an inlet body coupled to an outlet body, the inlet body comprising a fluid inlet, a first seal bead and a second seal bead, and the outlet body comprising a fluid outlet, and a seal secured between the inlet body and the outlet body, the seal having an inner ring and an outer ring, wherein the inner ring is engaged with the first seal bead and the outer ring is engaged with the second seal bead in a fully sealed position of the check valve assembly, wherein the inner ring is flexed away from the first seal bead and the outer ring is flexed away from the second seal bead in an open fluid flow position of the check valve assembly, and wherein the outer ring is engaged with the second seal bead and the inner ring is flexed away from the first seal bead in a partially sealed position of the check valve assembly. 
     Some of the disclosed embodiments provide a check valve assembly, comprising: an inlet body comprising a fluid inlet, first and second seal beads, and a central channel; an outlet body comprising a fluid outlet and a stem having a centering post, the centering post configured to be received by the central channel of the inlet body; and a seal comprising inner and outer rings, wherein the inner ring is configured to engage with the first seal bead and the outer ring is configured to engage with the second seal bead in a fully sealed position of the check valve assembly. 
     Some of the disclosed embodiments provide a method of manufacturing a check valve assembly, the method comprising: coupling the seal to the stem, wherein the centering post is inserted into a central hole of the seal and the seal rests on a shoulder of the stem; connecting the inlet body to the outlet body, wherein the outer ring of the seal is loaded by the second seal bead; and ultrasonically welding the inlet body to the outlet body, wherein the inner ring of the seal is secured between the shoulder of the stem and an end surface of the central channel of the inlet body, and wherein the inner ring of the seal is loaded by the first seal bead. 
     Some of the disclosed embodiments also provide an intravenous (IV) set, comprising: a fluid inlet tube; a fluid outlet tube; and a check valve assembly, comprising: an inlet body coupled to an outlet body, the inlet body comprising a fluid inlet, first and second seal beads, and a central channel, and the outlet body comprising a fluid outlet and a centering post, the centering post received by the central channel; and a seal coupled to the centering post, the seal having an inner ring and an outer ring, wherein the inner ring is engaged with the first seal bead and the outer ring is engaged with the second seal bead in a fully sealed position of the check valve assembly, wherein the inner ring is flexed away from the first seal bead and the outer ring is flexed away from the second seal bead in an open fluid flow position of the check valve assembly, and wherein the outer ring is engaged with the second seal bead and the inner ring is flexed away from the first seal bead in a partially sealed position of the check valve assembly. 
     Additional features and advantages of the disclosure will be set forth in the description below and, in part, will be apparent from the description or may be learned by practice of the disclosure. The objectives and other advantages of the disclosure will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure. 
         FIG.  1    depicts a schematic view of a typical assembled infusion set. 
         FIG.  2    is a perspective exploded view of an example check valve, according to some aspects of the disclosure. 
         FIG.  3    is a cross-sectional perspective view of the check valve of  FIG.  2   , according to some aspects of the disclosure. 
         FIG.  4    is a partial cross-sectional perspective view of the check valve of  FIG.  2    in a pre-assembled state, according to some aspects of the disclosure. 
         FIG.  5    is a front view of the check valve of  FIG.  4   , according to some aspects of the disclosure. 
         FIG.  6    is a partial cross-sectional perspective view of the check valve of  FIG.  2    in an assembled state, according to some aspects of the disclosure. 
         FIG.  7    is a front view of the check valve of  FIG.  6   , according to some aspects of the disclosure. 
         FIG.  8    is a perspective view of a check valve seal, according to some aspects of the disclosure. 
         FIG.  9    is a front view of the check valve seal of  FIG.  8   , according to some aspects of the disclosure. 
         FIG.  10    is a schematic view of the check valve of  FIG.  7    in an open flow state, according to some aspects of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below describes various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. Accordingly, dimensions are provided in regard to certain aspects as non-limiting examples. However, it will be apparent to those skilled in the art that the subject technology may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. 
     It is to be understood that the present disclosure includes examples of the subject technology and does not limit the scope of the appended claims. Various aspects of the subject technology will now be disclosed according to particular but non-limiting examples. Various embodiments described in the present disclosure may be carried out in different ways and variations, and in accordance with a desired application or implementation. 
     As shown in  FIG.  1   , a typical infusion set  30  may include a drip chamber  40 , a check valve  50 , a roller clamp  60  and Y-junctions  70 , all connected together by tubing  20 . A typical infusion set  30  can include additional infusion components (e.g., pinch clamps, filters) and can be formed of any combination of components and the tubing  20 . 
     Check valve  50  is typically formed from flexible (e.g., elastomeric) seals mounted within a fluid flow housing. Typically, the flexible seal is mounted such that the seal engages a seal bead in the housing in the sealed position and flexes away from the seal bead in an open flow position. However, if a particulate in the fluid becomes caught between the seal and the seal bead, a gap will remain between the seal and the seal bead when the check valve  50  returns to the sealed position. This gap allows for leakage (e.g., low flow leakage) of fluid when the check valve  50  is supposed to be fully sealed to prevent any fluid flow. 
     According to aspects of the disclosure, a check valve assembly is provided with a seal having dual sealing rings and a housing having dual seal beads. The outer seal prevents particulate (e.g., grit) from reaching the inner seal, thus allowing the inner seal to fully close and to seal off fluid flow. 
       FIGS.  2 - 10    illustrate a check valve assembly shown as check valve  100 , according to some aspects of the disclosure. The check valve  100  includes a housing  110  having an inlet body  120 , an outlet body  130  and a seal  140 . 
     The inlet body  120  has a fluid inlet  122  configured to connect with a fluid source (e.g., IV bag, infusion pump, needleless syringe) via an IV tube (e.g., tubing  20 ). The inlet body  120  includes a first seal bead  124  and a second seal bead  126 , each disposed on an inner surface  121  of the inlet body  120 . The first and second seal beads  124 ,  126  may be configured as cylindrical ribs or teeth, for example. As shown in  FIG.  3   , the first seal bead  124  is a circular rib disposed around a central channel  128  in the inlet body  120 . The central channel  128  has an end surface  129 . 
     As shown in  FIG.  5   , the first seal bead  124  has an inner diameter D 1  and a height H 1 . The second seal bead  126  is a circular rib disposed concentrically around the first seal bead  124 , the second seal bead  126  having an inner diameter D 2  and a height H 2 . Here, the height H 2  is greater than the height H 1  so that the second seal bead  126  extends further away from the inner surface  121  than does the first seal bead  124 . In some aspects of the disclosure, an end surface  123  of the first seal bead  124  and/or an end surface  125  of the second seal bead  126  is angled such that only a point portion of the end surface  123 ,  125  engages with the seal  140  when the check valve  100  is in a fully sealed (e.g., closed) position. 
     The outlet body  130  has a fluid outlet  132  configured to connect with a downstream fluid component (e.g., roller clamp  60 ). The outlet body  130  includes a stem  134  having a centering post  136  and a shoulder  138 , the centering post  136  is configured to be received by the central channel  128  of the inlet body  120 . 
     The seal  140  includes an inner ring  142  and an outer ring  144 . The inner ring  142  has a thickness T 1  and the outer ring  144  has a thickness T 2 , where thickness T 1  is greater than thickness T 2  (see  FIG.  9   ). The inner ring  142  has a diameter D S1  and the outer ring  144  has a diameter D S2 , where diameter D S2  is greater than diameter D S1 . The diameter D S1  of the inner ring  142  of the seal  140  is greater than the inner diameter D 1  of the first seal bead  124 , and the diameter D S2  of the outer ring  144  of the seal  140  is greater than the outer diameter D 2  of the second seal bead  126 . The seal  140  also includes a central hole  146  that mounts on the centering post  136  of the outlet body  130  and a portion of the inner ring  142  that rests on the shoulder  138  of the outlet body  130 . The seal  140  may be formed of any flexible material (e.g., silicone), where the inner ring  142  is somewhat flexible and the outer ring  144  is thinner and more flexible. For example, the outer ring may be as thin as mold flash. 
     To assemble the check valve  100 , the seal  140  is coupled to/mounted on the centering post  136  of the outlet body  130  via the central hole  146  of the seal  140 , where the inner ring  142  rests on the shoulder  138  of the outlet body  130 . As shown in  FIGS.  4  and  5   , the inlet body  120  is coupled to/mounted on the outlet body  130 , which causes the outer ring  144  to be engaged and loaded by the second seal bead  126 . As shown in  FIGS.  6  and  7   , the inlet body  120  and the outlet body  130  may then be sealed together (e.g., ultrasonic welding), which causes the inner ring  142  to be sandwiched and/or secured between the shoulder  138  of the outlet body  130  and the end surface  129  of the central channel  128 , and further causes the inner ring  142  to be engaged and loaded by the first seal bead  124 . Thus, during assembly of the check valve  100 , the outer ring  144  is loaded first and the inner ring  142  is loaded second. In some aspects of the disclosure, the inner ring  142  and the outer ring  144  have different preload forces. 
     As shown in  FIG.  10   , the check valve  100  is in an open or fluid flow mode when fluid enters through the fluid inlet  122  with sufficient force to force the inner ring  142  and the outer ring  144  away from the first seal bead  124  and the second seal bead  126 , respectively. Thus, the inner ring  142  is flexed away from the first seal bead  124  and the outer ring  144  is flexed away from the second seal bead  126  in this open fluid flow position of the check valve assembly  100 . The fluid flows through the interior volume  112  of the housing  110  and out the fluid outlet  132  of the outlet body  130 . When the fluid pressure decreases or ceases (e.g., fluid flow slows or stops), the check valve  100  moves to a closed position. 
     As the check valve  100  closes, the outer ring  144  closes first by flexing back to its starting position to engage the second seal bead  126 . This occurs because the outer ring  144  is thinner and more flexible than the inner ring  142 , thus causing the outer ring  144  to flex faster and/or through a great range of motion than the inner ring  142 . By closing first, the outer ring  144  creates an initial seal that prevents particulate or grit from reaching the inner ring  142 . Thus, the outer ring  144  is engaged with the second seal bead  126  and the inner ring  142  is still flexed away from the first seal bead  124  in this partially sealed position of the check valve assembly  100 . 
     After the outer ring  144  closes, the inner ring  142  then closes by flexing back to its starting position to engage the first seal bead  124 . Thus, the inner ring  142  is able to close completely because of the absence of particulate or grit caused by the earlier sealing of the outer ring  144 . Thus, the inner ring  142  is engaged with the first seal bead  124  and the outer ring  144  is engaged with the second seal bead  126  in this fully sealed position of the check valve assembly  100 . 
     For the seal  140 , the inner ring  142  is the primary seal and the outer ring  144  is the secondary seal. Characteristics of the inner ring  142  primary seal determines the cracking pressure of the check valve  100  (e.g., the amount of fluid pressure required to open or crack the seal  140 ), such as the flexibility of the inner ring  142 , for example. In some aspects of the disclosure, the cracking pressure is determined by the inner ring  142  because the outer ring  144  secondary seal is very thin and has little resistance to the fluid pressure. In some aspects of the disclosure, the cracking pressure is determined by the inner ring  142  because the inner ring  142  primary seal is sealed against the first seal bead  124 , which prevents any fluid from reaching the outer ring  144  secondary seal. Once the cracking pressure is reached in the check valve  100 , both the inner ring  142  primary seal and the outer ring  144  secondary seal move away from the first seal bead  124  and the second seal bead  126  (e.g., open up) to allow fluid to flow past the seal  140 . 
     The operation of the check valve  100  may be varied by modifying different elements. For example, increasing/decreasing either or both the thickness T 1  of the inner ring  142  and the thickness T 2  of the outer ring  144 , increasing/decreasing either or both the diameter D 1  of the inner ring  142  and the diameter D 2  of the outer ring  144 , increasing/decreasing either or both the height H 1  of the first seal bead  124  and the height H 2  of the second seal bead  126 , and using various materials to change the stiffness or flexibility of either or both the inner ring  142  and the outer ring  144  may change the cracking pressure and/or flow characteristics of the check valve  100 . 
     It is understood that any specific order or hierarchy of blocks in the methods of processes disclosed is an illustration of example approaches. Based upon design or implementation preferences, it is understood that the specific order or hierarchy of blocks in the processes may be rearranged, or that all illustrated blocks be performed. In some implementations, any of the blocks may be performed simultaneously. 
     The present disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. The disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. 
     A reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the invention. 
     The word “exemplary” is used herein to mean “serving as an example or illustration.” Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. In one aspect, various alternative configurations and operations described herein may be considered to be at least equivalent. 
     As used herein, the phrase “at least one of” preceding a series of items, with the term “or” to separate any of the items, modifies the list as a whole, rather than each item of the list. The phrase “at least one of” does not require selection of at least one item; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrase “at least one of A, B, or C” may refer to: only A, only B, or only C; or any combination of A, B, and C. 
     A phrase such as an “aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. An aspect may provide one or more examples. A phrase such as an aspect may refer to one or more aspects and vice versa. A phrase such as an “embodiment” does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. A disclosure relating to an embodiment may apply to all embodiments, or one or more embodiments. An embodiment may provide one or more examples. A phrase such an embodiment may refer to one or more embodiments and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A configuration may provide one or more examples. A phrase such a configuration may refer to one or more configurations and vice versa. 
     In one aspect, unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. In one aspect, they are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain. 
     It is understood that the specific order or hierarchy of steps, operations or processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps, operations or processes may be rearranged. Some of the steps, operations or processes may be performed simultaneously. Some or all of the steps, operations, or processes may be performed automatically, without the intervention of a user. The accompanying method claims, if any, present elements of the various steps, operations or processes in a sample order, and are not meant to be limited to the specific order or hierarchy presented. 
     All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112 (f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.” Furthermore, to the extent that the term “include,” “have,” or the like is used, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim. 
     The Title, Background, Summary, Brief Description of the Drawings and Abstract of the disclosure are hereby incorporated into the disclosure and are provided as illustrative examples of the disclosure, not as restrictive descriptions. It is submitted with the understanding that they will not be used to limit the scope or meaning of the claims. In addition, in the Detailed Description, it can be seen that the description provides illustrative examples and the various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed configuration or operation. The following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter. 
     The claims are not intended to be limited to the aspects described herein, but are to be accorded the full scope consistent with the language claims and to encompass all legal equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of 35 U.S.C. § 101, 102, or 103, nor should they be interpreted in such a way.