Patent Description:
Document <CIT> discloses an IV check valve with a body having a cavity in flow communication with an inlet conduit and an outlet conduit, a valve seat disposed in the body, a diaphragm responsive to fluid flow through the body, and a screen disposed in the body between the inlet conduit and valve seat. The inlet and outlet conduits are connectible to the IV tubes. The diaphragm is spaced from the valve seat in response to fluid flow from inlet to outlet conduits and is sealed against the seat in response to fluid from outlet to inlet conduits.

<CIT> discloses a nonreturn valve centre diaphragm which can be pressed against a first lip seal ringing the centre of the valve. The diaphragm moves axially on a pin and can be pressed onto a second lip which runs round the centre of the valve and lies radially inside the first lip seal. The flow path runs through both lips when the valve is open.

The present disclosure provides medical fluid flow check valves having dual sealing rings.

In one or more embodiments, a check valve assembly is provided. The check valve assembly includes a housing having an inlet body. The inlet body includes a fluid inlet, a first seal bead having a first height, a second seal bead having a second height and a central channel. The housing also includes an outlet body. The outlet body includes 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. The check valve assembly also includes a seal having an inner ring having a first thickness and an outer ring having a second thickness less than the first thickness. 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.

In one or more aspects, the first height of the first seal bead is less than the second height of the second seal bead. In one or more aspects, the first height of the first seal bead and the first thickness of the inner ring equals the second height of the second seal bead and the second thickness of the outer ring. In one or more aspects, the first seal bead is a circular rib extending orthogonally from an inner surface of the inlet body and disposed around the central channel. In one or more aspects, the second seal bead is a circular rib extending orthogonally from the inner surface of the inlet body and disposed concentrically around the first seal bead. In one or more aspects, a diameter of the inner ring is greater than a diameter of the first seal bead and a diameter of the outer ring is greater than a diameter of the second seal bead.

In one or more aspects, an end surface of one of the first seal bead and the second seal bead is angled. In one or more aspects, only a point portion of the end surface is engaged with the seal in the fully sealed position of the check valve assembly. In one or more aspects, the seal is coupled to the centering post via a central hole of the seal. In one or more aspects, the stem includes a shoulder and the inner ring of the seal is engaged by the shoulder. In one or more aspects, the seal is sandwiched between the shoulder of the stem and an end surface of the central channel. In one or more aspects, the inlet body and the outlet body are sealed together.

In one or more aspects, one of the inlet body and the outlet body is configured to couple with intravenous tubing. In one or more aspects, a flexibility of the inner ring determines a cracking pressure for the check valve assembly. In one or more aspects, 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. In one or more aspects, 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.

In one or more embodiments, a method of manufacturing the above described check valve assembly is provided. The method includes 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. The method also includes connecting the inlet body to the outlet body, wherein the outer ring of the seal is loaded by the second seal bead. The method further includes 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.

In one or more embodiments, a fluid flow set is provided. The fluid flow set includes a fluid inlet tube, a fluid outlet tube and a check valve assembly. The check valve assembly includes a housing having an inlet body coupled to an outlet body, the inlet body having a fluid inlet, a central channel and a first seal bead having a different height than a second seal bead, and the outlet body having a fluid outlet and a centering post, the centering post received by the central channel. The check valve assembly also includes a seal coupled to the centering post, the seal having an inner ring and an outer ring where the outer ring is less thick than the inner ring. 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. 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. 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.

In one or more aspects, the first seal bead is a circular rib extending orthogonally from an inner surface of the inlet body and disposed around the central channel, and wherein the second seal bead is a circular rib extending orthogonally from the inner surface of the inlet body and disposed concentrically around the first seal bead. In one or more aspects, an end surface of each of the first seal bead and the second seal bead is angled, and wherein only a portion of each end surface is engaged with the seal in the fully 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.

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.

Accordingly, dimensions are provided in regard to certain aspects as non-limiting examples.

As shown in <FIG>, a typical infusion set <NUM> may include a drip chamber <NUM>, a check valve <NUM>, a roller clamp <NUM> and Y-junctions <NUM>, all connected together by tubing <NUM>. A typical infusion set <NUM> can include additional infusion components (e.g., pinch clamps, filters) and can be formed of any combination of components and the tubing <NUM>.

Check valve <NUM> 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 <NUM> returns to the sealed position. This gap allows for leakage (e.g., low flow leakage) of fluid when the check valve <NUM> 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.

<FIG> illustrate a check valve assembly shown as check valve <NUM>, according to some aspects of the disclosure. The check valve <NUM> includes a housing <NUM> having an inlet body <NUM>, an outlet body <NUM> and a seal <NUM>.

The inlet body <NUM> has a fluid inlet <NUM> configured to connect with a fluid source (e.g., IV bag, infusion pump, needleless syringe) via an IV tube (e.g., tubing <NUM>). The inlet body <NUM> includes a first seal bead <NUM> and a second seal bead <NUM>, each disposed on an inner surface <NUM> of the inlet body <NUM>. The first and second seal beads <NUM>, <NUM> may be configured as cylindrical ribs or teeth, for example. As shown in <FIG>, the first seal bead <NUM> is a circular rib disposed around a central channel <NUM> in the inlet body <NUM>. The central channel <NUM> has an end surface <NUM>.

As shown in <FIG>, the first seal bead <NUM> has an inner diameter D<NUM> and a height H<NUM>. The second seal bead <NUM> is a circular rib disposed concentrically around the first seal bead <NUM>, the second seal bead <NUM> having an inner diameter D<NUM> and a height H<NUM>. Here, the height H<NUM> is greater than the height H<NUM> so that the second seal bead <NUM> extends further away from the inner surface <NUM> than does the first seal bead <NUM>. In some aspects of the disclosure, an end surface <NUM> of the first seal bead <NUM> and/or an end surface <NUM> of the second seal bead <NUM> is angled such that only a point portion of the end surface <NUM>, <NUM> engages with the seal <NUM> when the check valve <NUM> is in a fully sealed (e.g., closed) position.

The outlet body <NUM> has a fluid outlet <NUM> configured to connect with a downstream fluid component (e.g., roller clamp <NUM>). The outlet body <NUM> includes a stem <NUM> having a centering post <NUM> and a shoulder <NUM>, the centering post <NUM> is configured to be received by the central channel <NUM> of the inlet body <NUM>.

The seal <NUM> includes an inner ring <NUM> and an outer ring <NUM>. The inner ring <NUM> has a thickness T<NUM> and the outer ring <NUM> has a thickness T<NUM>, where thickness T<NUM> is greater than thickness T<NUM> (see <FIG>). The inner ring <NUM> has a diameter DS1 and the outer ring <NUM> has a diameter DS2, where diameter DS2 is greater than diameter DS1. The diameter DS1 of the inner ring <NUM> of the seal <NUM> is greater than the inner diameter D<NUM> of the first seal bead <NUM>, and the diameter DS2 of the outer ring <NUM> of the seal <NUM> is greater than the outer diameter D<NUM> of the second seal bead <NUM>. The seal <NUM> also includes a central hole <NUM> that mounts on the centering post <NUM> of the outlet body <NUM> and a portion of the inner ring <NUM> that rests on the shoulder <NUM> of the outlet body <NUM>. The seal <NUM> may be formed of any flexible material (e.g., silicone), where the inner ring <NUM> is somewhat flexible and the outer ring <NUM> is thinner and more flexible. For example, the outer ring may be as thin as mold flash.

To assemble the check valve <NUM>, the seal <NUM> is coupled to/mounted on the centering post <NUM> of the outlet body <NUM> via the central hole <NUM> of the seal <NUM>, where the inner ring <NUM> rests on the shoulder <NUM> of the outlet body <NUM>. As shown in <FIG>, the inlet body <NUM> is coupled to/mounted on the outlet body <NUM>, which causes the outer ring <NUM> to be engaged and loaded by the second seal bead <NUM>. As shown in <FIG>, the inlet body <NUM> and the outlet body <NUM> may then be sealed together (e.g., ultrasonic welding), which causes the inner ring <NUM> to be sandwiched and/or secured between the shoulder <NUM> of the outlet body <NUM> and the end surface <NUM> of the central channel <NUM>, and further causes the inner ring <NUM> to be engaged and loaded by the first seal bead <NUM>. Thus, during assembly of the check valve <NUM>, the outer ring <NUM> is loaded first and the inner ring <NUM> is loaded second. In some aspects of the disclosure, the inner ring <NUM> and the outer ring <NUM> have different preload forces.

As shown in <FIG>, the check valve <NUM> is in an open or fluid flow mode when fluid enters through the fluid inlet <NUM> with sufficient force to force the inner ring <NUM> and the outer ring <NUM> away from the first seal bead <NUM> and the second seal bead <NUM>, respectively. Thus, the inner ring <NUM> is flexed away from the first seal bead <NUM> and the outer ring <NUM> is flexed away from the second seal bead <NUM> in this open fluid flow position of the check valve assembly <NUM>. The fluid flows through the interior volume <NUM> of the housing <NUM> and out the fluid outlet <NUM> of the outlet body <NUM>. When the fluid pressure decreases or ceases (e.g., fluid flow slows or stops), the check valve <NUM> moves to a closed position.

As the check valve <NUM> closes, the outer ring <NUM> closes first by flexing back to its starting position to engage the second seal bead <NUM>. This occurs because the outer ring <NUM> is thinner and more flexible than the inner ring <NUM>, thus causing the outer ring <NUM> to flex faster and/or through a great range of motion than the inner ring <NUM>. By closing first, the outer ring <NUM> creates an initial seal that prevents particulate or grit from reaching the inner ring <NUM>. Thus, the outer ring <NUM> is engaged with the second seal bead <NUM> and the inner ring <NUM> is still flexed away from the first seal bead <NUM> in this partially sealed position of the check valve assembly <NUM>.

After the outer ring <NUM> closes, the inner ring <NUM> then closes by flexing back to its starting position to engage the first seal bead <NUM>. Thus, the inner ring <NUM> is able to close completely because of the absence of particulate or grit caused by the earlier sealing of the outer ring <NUM>. Thus, the inner ring <NUM> is engaged with the first seal bead <NUM> and the outer ring <NUM> is engaged with the second seal bead <NUM> in this fully sealed position of the check valve assembly <NUM>.

For the seal <NUM>, the inner ring <NUM> is the primary seal and the outer ring <NUM> is the secondary seal. Characteristics of the inner ring <NUM> primary seal determines the cracking pressure of the check valve <NUM> (e.g., the amount of fluid pressure required to open or crack the seal <NUM>), such as the flexibility of the inner ring <NUM>, for example. In some aspects of the disclosure, the cracking pressure is determined by the inner ring <NUM> because the outer ring <NUM> 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 <NUM> because the inner ring <NUM> primary seal is sealed against the first seal bead <NUM>, which prevents any fluid from reaching the outer ring <NUM> secondary seal. Once the cracking pressure is reached in the check valve <NUM>, both the inner ring <NUM> primary seal and the outer ring <NUM> secondary seal move away from the first seal bead <NUM> and the second seal bead <NUM> (e.g., open up) to allow fluid to flow past the seal <NUM>.

The operation of the check valve <NUM> may be varied by modifying different elements. For example, increasing/decreasing either or both the thickness T<NUM> of the inner ring <NUM> and the thickness T<NUM> of the outer ring <NUM>, increasing/decreasing either or both the diameter D<NUM> of the inner ring <NUM> and the diameter D<NUM> of the outer ring <NUM>, increasing/decreasing either or both the height H<NUM> of the first seal bead <NUM> and the height H<NUM> of the second seal bead <NUM>, and using various materials to change the stiffness or flexibility of either or both the inner ring <NUM> and the outer ring <NUM> may change the cracking pressure and/or flow characteristics of the check valve <NUM>.

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.

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.

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.

Claim 1:
A check valve assembly (<NUM>), comprising:
a housing (<NUM>) comprising:
an inlet body (<NUM>) comprising:
a fluid inlet (<NUM>);
a first seal bead (<NUM>) having a first height;
a second seal bead (<NUM>) having a second height; and
a central channel (<NUM>);
and an outlet body (<NUM>) comprising:
a fluid outlet (<NUM>); and
a stem (<NUM>) having a centering post (<NUM>), the centering post (<NUM>) configured to be received by the central channel (<NUM>) of the inlet body (<NUM>);
wherein the check valve assembly (<NUM>) further comprises
a seal (<NUM>), characterised in that the seal (<NUM>) comprises:
an inner ring (<NUM>) having a first thickness T<NUM>; and
an outer ring (<NUM>) having a second thickness T<NUM> less than the first thickness T<NUM>, wherein the inner ring (<NUM>) is engaged with the first seal bead (<NUM>) and the outer ring (<NUM>) is engaged with the second seal bead (<NUM>) in a fully sealed position of the check valve assembly (<NUM>).