Abstract:
A fluid connector that is designed to work with a wide range of tube configurations and sizes by being able to adjust to the configuration and size of tube being connected to. The fluid connector can also include a pressure driven actuation resistance mechanism to achieve higher pressures. Therefore, a single fluid connector can be used over a wide range of applications. This permits the creation of a standardized cost effective fluid connector design.

Description:
FIELD 
       [0001]    This disclosure relates to a fluid connector that can be used to, for example, connect a first fluid system with a second fluid system for transferring fluids, including gaseous or liquid fluids, between the first and second fluid systems, or for sealing a fluid system using the fluid connector. 
       BACKGROUND 
       [0002]    An example of a fluid connector relating to this disclosure is described in U.S. Pat. No. 5,209,528. As described in this patent, collets are arranged to close around a tube under control of a retractable sleeve. The collets are not designed to put significant gripping pressure on the outside of the tube. Instead, the collets are designed to wedge between the tube and the sleeve, with a feature on the tube, such as a bead, barb, threads or the like, held by the collets. When the sleeve is in a locked position, the sleeve slides over the collets and holds the collets in a collapsed position around the tube. When the sleeve is pulled backward to a retracted position against the biasing force of a spring, the collets are biased open by a biasing spring. Due to the construction of the collets and an internal piston within the fluid connector, the collets prevent the sleeve from being biased back to the locked position until such time as an end of the tube is inserted into the connector and the piston is pushed backward. Therefore, when the fluid connector is not connected to a tube, the collets are held open ready to receive the end of the tube, and the collets hold the sleeve back at the retracted position. 
         [0003]    The type of fluid connector described in U.S. Pat. No. 5,209,528 is designed to work with a specific tube size having a specific configuration such as a bump, bead, barb, flare or the like. If one tries to connect to a tube having a larger or smaller diameter, or having a different configuration, the fluid connector will not attach or incorrectly attach to the tube permitting separation of the tube from the fluid connector during use. As a result, this type of fluid connector tends to be custom made for each tube configuration and size, so that a number of fluid connectors need to be produced for the various anticipated tube configurations and sizes to be encountered. Due to the custom manufacturing, these types of fluid connectors are expensive to manufacture, have long lead times to produce, and do not allow for variations in the parts forming the fluid connectors. In addition, often times the tolerance of the tubes to be attached to this type of fluid connector can vary greatly, the tubes are not within specification, the tubes are out of round, or there is other variation in the tube configuration or size, thereby preventing use of the fluid connector or rendering use of the fluid connector ineffective. 
       SUMMARY 
       [0004]    A fluid connector is described herein that is designed to work with a wide range of tube configurations (such as a bump, bead, barb, flare or the like to be held by the collets) and tube sizes by being able to self-adjust to the configuration and size of tube being connected to. Therefore, a single fluid connector can be used over a wide range of applications. This permits the creation of so-called standard, off-the-shelf fluid connectors, instead of being custom made, permitting the fluid connector to be made in volume, which reduces costs and production lead times. 
         [0005]    In the fluid connector described herein, the interface between the collets and the sleeve is modified to achieve a desired range of motion of the collets to collapse around the different tube configurations and diameters. In one embodiment, the collets (or the sleeve) have a relatively shallow angle surface, while the inner surface of the sleeve (or the outer surface of the collets) has multiple step diameters. In addition, because of the interface between the collets and the sleeve, the sleeve is always biased to return to a default or locked position up and over the collets holding the collets in the collapsed position, even when a tube is not inserted into the end of the fluid connector. 
         [0006]    In an optional embodiment, to help prevent the sleeve from being pushed backward by fluid pressure to a retracted position against the bias of the spring, a pressure driven actuation resistance mechanism can be provided. The pressure driven actuation resistance mechanism generates an actuation resistance force on the sleeve when the fluid connector is under pressure, with the amount of actuation resistance force varying based on the pressure of the fluid internal to the fluid connector. As the fluid pressure increases, more force is exerted on the collets which push outward against the sleeve tending to push the sleeve open to the retracted position. However, as the fluid pressure increases, the actuation resistance force generated by the pressure driven actuation resistance mechanism on the sleeve is increased thereby counteracting the force of the collets on the sleeve. Likewise, as the fluid pressure decreases, the actuation resistance force generated by the pressure driven actuation resistance mechanism on the sleeve is also decreased. In one embodiment, the pressure driven actuation resistance mechanism can include a ball. 
         [0007]    In addition, the main seal used in the fluid connector described herein has a construction that permits the main seal to seal with a range of tubes and tube shapes. 
     
    
     
       DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a fluid connector described herein. 
           [0009]      FIG. 2  is a longitudinal cross-sectional view of the fluid connector of  FIG. 1  with the sleeve in a default or locked position. 
           [0010]      FIG. 3  is a longitudinal cross-sectional view similar to  FIG. 2  but with the sleeve in a retracted position. 
           [0011]      FIG. 4  is a longitudinal cross-sectional view similar to  FIG. 2  prior to connection to a tube. 
           [0012]      FIG. 5  is a longitudinal cross-sectional view similar to  FIG. 4  with the fluid connector connected to the tube. 
           [0013]      FIG. 6  is a cross-sectional view of a portion of the front end of the fluid connector detailing an example of an interface between the sleeve and the collets, and with the sleeve retracted and the collets expanded to an open position. 
           [0014]      FIG. 7  is a cross-sectional view similar to  FIG. 6  with the sleeve at one engaged position on the collet surface to collapse the collets to grip a tube having a larger diameter. 
           [0015]      FIG. 8  is a cross-sectional view similar to  FIG. 6  with the sleeve at another engaged position on the collet surface to collapse the collets to grip a tube having a smaller diameter. 
           [0016]      FIG. 9  is a cross-sectional view similar to  FIGS. 6-8  but with the engagement surfaces of the collets and the sleeve reversed. 
           [0017]      FIG. 10  is a longitudinal cross-sectional view of another embodiment of a fluid connector prior to connecting to a tube, with the fluid connector including a pressure driven actuation resistance mechanism. 
           [0018]      FIG. 11  is a longitudinal cross-sectional view similar to  FIG. 10  but with the fluid connector connected to the tube and the pressure driven actuation resistance mechanism engaged with the sleeve. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    With reference initially to  FIG. 1 , an embodiment of a fluid connector  10  is illustrated. In this example, the fluid connector  10  is a generally cylindrical construction that includes a body  12 , a collet assembly  14 , a sleeve  16 , and a piston  18  (visible in  FIGS. 2-3 ). The fluid connector  10  can be used to, for example, connect a first fluid system with a second fluid system for transferring fluids, including gaseous or liquid fluids, between the first and second fluid systems, or the fluid connector  10  can connect to a fluid system for sealing the fluid system using the fluid connector  10 . 
         [0020]    In one embodiment, the fluid connector  10  can be integrally, but removably connected to the first fluid system via a fluid opening  20  formed in the body  12 . In other embodiments, the fluid system to which the fluid connector  10  is integrally connected to can be considered the second fluid system. In use of the fluid connector  10 , the fluid connector  10  is designed to detachably connect to a tube  22  (visible in  FIG. 4 ) of the second fluid system (or of the first fluid system if the fluid connector  10  is integrally connected to the second fluid system). When the fluid connector  10  connects to the tube  12 , fluid can be directed between the first and second fluid systems through the fluid connector  10 . 
         [0021]    Referring now to  FIGS. 1-3 , the body  12  is a generally elongated structure having a first or front end  24  and a second or rear end  26 . At or near the first end  24 , the body  12  includes a radially inward facing channel in which a piston seal  28  is disposed. The piston seal  28  seals with an exterior surface of the piston  18  to prevent leakage of fluid between the piston  18  and the body  12 . To the rear of the front end  24 , a radial outward facing circumferential channel  30  is formed in the body  12 . The channel  30  is designed to receive rear ends of collets  40  of the collet assembly  14  as discussed further below. 
         [0022]    A fluid flow channel  32  is formed through the body  12  from the first end  24  to the second end  26 , with the fluid flow channel  32  in fluid communication with the fluid opening  20  which is located at or near the second end  26 . In the illustrated embodiment, the fluid opening  20  extends radially outward in the body  12  and in use can receive a fluid fitting that directs fluid into or from the body  12  via the fluid opening  20 . However, the fluid opening  20  can have other configurations as well, such as extending at an angle in the body  12  or extending axially through the second end  26 . In some embodiments, the fluid opening  20  could be plugged if the fluid connector  10  is used to seal a fluid system. 
         [0023]    With continued reference to  FIGS. 1-3 , the collet assembly  14  comprises a plurality of collets  40  that are circumferentially arranged side-by-side around a central longitudinal axis A-A of the fluid connector  10 . A rear end  42  of each collet  40  is disposed in the channel  30  on the body  12 , and a suitable spring  44 , for example a garter spring or elastomeric material, is disposed in a channel formed in the rear end  42  of each collet  40 . Each collet  40  includes a radial inward channel  46  that receives an enlarged boss  48  formed at or near the first end  24  of the body  12 . The spring  44  applies a radially inward biasing force to the collets  40  that tends to force the collets  40  to pivot about the boss  48  from a collapsed or closed position (shown in  FIG. 2 ) to an expanded or open position (shown in  FIG. 3 ) when the sleeve  16  is pulled axially backward from a default or locking position (shown in  FIG. 2 ) to a retracted position (shown in  FIG. 3 ) as discussed further below. 
         [0024]    The sleeve  16  is slidably disposed on the body  12  and on the collet assembly  14  for axial sliding movement in the direction of the longitudinal axis A-A. The sleeve  16  includes a front end  50  and a rear end  52 . The sleeve  16  includes a radially inward projecting shoulder  54  on the interior thereof that can slide on an outer surface of the body  12 . The shoulder  54  also forms a surface against which one end of a sleeve spring  56 , for example a coil spring, can abut for biasing the sleeve  16  toward the default position shown in  FIG. 2 . The other end of the sleeve spring  56  abuts against a retaining ring  58  that is secured to the outer surface of the body  12 . As also shown in  FIG. 2 , the shoulder  54  of the sleeve  16  can also abut against the rear ends  42  of the collets  40 . 
         [0025]    The sleeve  16  can be manually retracted by a user from the default position shown in  FIG. 2  to the position shown in  FIG. 3 . When the sleeve  16  is released, and the tube  22  is not inserted into the fluid connector  10 , the sleeve spring  56  biases the sleeve  16  so that the sleeve  16  automatically returns back to the default position shown in  FIG. 2 . At the default position, the sleeve  16  is up and over the collets  40  holding the collets  40  at their most collapsed position. The sleeve  16  can also be formed with one or more suitable grip enhancement features  60  that aid a user in retracting the sleeve  16 . For example, as illustrated in  FIGS. 1 and 2 , the grip enhancement feature  60  can comprise an enlarged section of the sleeve  16  at or near the rear end  52  thereof formed with a circumferential concavity that aids a user&#39;s hand in gripping the sleeve  16  when pulling back on the sleeve  16  and perhaps even when pushing the sleeve  16  forward toward the default position. 
         [0026]    A rear end  62  of the piston  18  is disposed within the first end  24  of the body  12  and a front end  64  of the piston  18  projects beyond the body  12 . The piston  18  forms a fluid flow channel that is a continuation of the fluid flow channel  32  of the body  12  so that fluid can flow through the piston  18 . The piston  18  is slideable within the body  12  relative to the body  12  in the direction of the longitudinal axis A-A. A biasing spring  66 , for example a coil spring, is engaged at one end with the body  12  and is engaged at an opposite end thereof with a shoulder  68  formed within the piston  18 . The biasing spring  66  biases the piston  18  in a direction away from the body  12  (or to the left in  FIG. 2 ), but permits the piston  18  to be pushed backward against the bias of the spring  66  further into the body  12 . 
         [0027]    A main seal  70  is disposed within the front end  64  of the piston  18  so that the main seal  70  is movable with the piston  18 . The main seal  70  is positioned and configured to seal with an end of the tube  22  when the tube  22  is inserted into the fluid connector  10 . In one embodiment, the main seal  70  is configured to permit it to seal with a plurality of sizes and configurations of tube ends. For example, as illustrated in  FIG. 2 , the main seal  70  can have an inverted cone shape with an inwardly and rearwardly sloping sealing surface  72 . The sealing surface  72  permits the main seal  70  to seal with different sizes of the tube ends, as well as tube ends of different configurations. The main seal  70  also has a passage  74  that aligns with the fluid flow channel through the piston  18  and the fluid flow channel  32  in the body  12  to form a continuous fluid flow passage through the fluid connector  10 . 
         [0028]    The fluid connector  10  described so far operates generally as follows. The tube  22 , or other structure the fluid connector  10  is to attach to, has a configuration that includes one or more protruding features  82  to permit the collets  40  to hold the tube  22  or other structure. Examples of protruding features  82  can include, but are not limited to, a bead, barb, threads or the like. With reference to  FIGS. 3-5 , to attach to the tube  22 , a user manually retracts the sleeve  16  to the retracted position shown in  FIG. 3 . This permits the collets  40  to expand outwardly due to the biasing force of the spring  44 . The end of the tube  22  is then inserted into the end of the fluid connector  10  through the opening formed by the expanded collets  40 . The end of the tube  22  engages the angled surface  72  of the main seal  70  and the piston  18  is pushed backward against the force of the spring  66 . The user then releases the sleeve  16  which is biased by the spring  56  back toward the default position. As the sleeve  16  travels toward the default position, the inner surface of the sleeve  16  at the front end  50  thereof rides up and over the outer surfaces of the collets  40 , forcing the collets  40  to pivot radially inwardly to collapse around the tube  22  ( FIG. 5 ). As seen in  FIG. 5 , the collets  40  latch just beyond the protruding feature  82  of the tube  22  to connect the fluid connector  10  to the tube  22  without applying significant gripping pressure on the tube  22 . In this type of connector, the collets  40  provide a radial force on the tube  22  but they do not provide a gripping force. 
         [0029]    Referring now to  FIGS. 6-8 , the interface between the exterior surface of the collets  40  and the interior surface of the sleeve  16  at the front end  50  is configured to permit the collets  40  to self-adjust to different diameters and configurations of the tube  22  when the collets  40  are collapsed by the sleeve  16 , allowing the fluid connector  10  to connect to tubes having different tube configurations and diameters. In particular, in the embodiment illustrated in  FIGS. 6-8 , each collet  40  is provided with a relatively shallow angled exterior surface  90  that extends to a flat  91 , while the interior surface of the sleeve  16  at the front end  50  is provided with two or more actuation surfaces or steps  92   a,    92   b  having different inside diameters. 
         [0030]    The actuation surfaces  92   a,    92   b  are intended to engage on the angled exterior surfaces  90  of the collets  40  and collapse the collets  40  radially inward as the sleeve  16  is forced toward the default position by the spring  56  depending upon the diameter of the tube  22  being connected to. The angled collet surfaces  90  and the actuation surfaces  92   a,    92   b  are sized and position relative to one another so that the actuation surfaces  92   a,    92   b  will cause different amounts of inward movement of the collets  40  based on the diameter of the tube  22  being connected to. For example, as the sleeve  16  is biased back toward the default position, the actuation surface  92   a  will initially engage the angled surfaces  90  of the collets  40  forcing the collets  40  to begin collapsing around the tube  22  as shown in  FIG. 6 . The actuation surface  92   a  of the sleeve  16  continues to travel along the angled surfaces  90  forcing the collets  40  further radially inward. As the actuating surface  92   a  nears the end of the surfaces  90 , the smaller diameter actuation surface  92   b  begins engaging the angled surfaces  90  of the collets  40  as shown in  FIG. 7 . Because the actuation surface  92   b  has a smaller inner diameter than the actuation surface  92   a,  the actuation surface  92   b  forces the collets  40  to collapse even further radially inwardly. 
         [0031]    However, depending upon the diameter of the tube  22  being gripped, the tube  22  will control the amount of inward collapse of the collets  40 , which determines whether one or both of the actuation surfaces  92   a,    92   b  engage the collet surfaces  90 , and how far along the angled collet surfaces  90  the actuation surfaces  92   a,    92   b  travel. If the tube  22  is at the minimum diameter of the intended size range, the sleeve actuation surface  92   b  will slide over the flats  91  of the collets  40 . 
         [0032]    With reference to  FIG. 8 , the geometry between the angled collet surfaces  90  and the actuation surfaces  92   a,    92   b  is chosen to permit the above-described self-adjustment of the collets  40  to different diameters and configurations of the tube  22 . For example, the angled collet surfaces  90  have an angle A relative to horizontal and relative to the longitudinal axis A-A. The larger the angle A is, more force is created during use of the fluid connector  10  that pushes back on the sleeve  16  trying to open the fluid connector  10  as fluid pressure increases. The smaller the angle A is, the less movement of the collets  40 , i.e. the range of motion of the collets  40  is lowered, which limits the self-adjustment of the collets  40 . In one embodiment, the angle A can range from about 4 degrees to about 10 degrees. In another embodiment, the angle A can range from about 5 degrees to about 7 degrees. In another embodiment, the angle A can be about 5 degrees. In the illustrated example in  FIG. 8 , ØD 1  is the inside diameter of the sleeve  16  for the actuation surface  92   a,  ØD 2  is the inside diameter of the sleeve  16  for the actuation surface  92   b,  L 1  is the length of the actuation surface  92   a,  and L 2  is the length of each angled collet surface  90 . In one embodiment, L 1  and L 2  can be the same length. 
         [0033]    The angle A creates a frictional force between the collet surfaces  90  and the actuation surfaces  92   a,    92   b.  That frictional force, together with the biasing force of the sleeve spring  56 , creates a force that resists the push back force acting on the sleeve  16  that tends to open the fluid connector  10 . In one embodiment, the frictional force created by the angle A together with the biasing force of the sleeve spring  56  is equal to or greater than the push back force that is created when the angle A is about 4 degrees to about 10 degrees. Optionally, in some embodiments, a pressure driven actuation resistance mechanism described further below can be used to help supplement the combination of frictional force created by the angle A together with the biasing force of the sleeve spring  56 . 
         [0034]    In one embodiment, the geometry between the angled collet surfaces  90  and the actuation surfaces  92   a,    92   b  can be chosen to permit the fluid connector  10  to grip and seal with tubes having diameters over a diametrical range of about Ø0.100 (or about 2.54 mm). 
         [0035]    The collets  40  have been described as having the shallow angled exterior surface  90 , while the interior surface of the sleeve  16  is described as having the two or more actuation surfaces or steps  92   a,    92   b  having different inside diameters. In another embodiment illustrated in  FIG. 9 , the surfaces can be reversed, with the interior surface of the sleeve  16  having a shallow angled exterior surface  90 ′, similar to the surface  90 , and the exterior surface of each of the collets  40  having two or more actuation surfaces  92   a ′,  92   b ′, similar to the actuation surfaces  92   a,    92   b,  with different outside diameters. 
         [0036]      FIGS. 10 and 11  illustrate an embodiment where a fluid connector  100  is shown being attached to the tube  22  with the protruding feature  82 . The fluid connector  100  is substantially identical in construction to the fluid connector  10  and similar elements are called out using the same reference numerals. In this example, the fluid connector  100  is a generally cylindrical construction that includes the body  12 , the collet assembly  14 , the sleeve  16 , and the piston  18 . The fluid connector  100  can be used to, for example, connect a first fluid system with a second fluid system for transferring fluids, including gaseous or liquid fluids, between the first and second fluid systems, or the fluid connector  100  can connect to a fluid system for sealing the fluid system using the fluid connector  100 . 
         [0037]    With the fluid connector  100 , instead of the body  12  having a radial fluid opening  20  as in the fluid connector  10 , the body  12  of the fluid connector  100  has a fluid opening  102  that extends axially through the second end of the body  12 . In some embodiments, the fluid opening  102  could be plugged if the fluid connector  100  is used to seal a fluid system. 
         [0038]    The fluid connector  100  also differs from the fluid connector  10  in that the fluid connector  100  includes a pressure driven actuation resistance mechanism  104  to help prevent the sleeve  16  from being pushed backward by fluid pressure acting on the collets  40  to a retracted position against the bias of the sleeve spring  56 . A similar pressure driven actuation resistance mechanism  104  could be used on any one of the fluid connectors  10  in  FIGS. 1-9 . The pressure driven actuation resistance mechanism  104  is configured to generate an actuation resistance force on the interior surface of the sleeve  16 , with the amount of actuation resistance force varying based on the pressure of the fluid internal to the fluid connector  100 . As the fluid pressure internal to the fluid connector  100  increases, more force is exerted on the collets  40  which push outward against the sleeve  16  tending to push the sleeve  16  open to the retracted position. However, as the fluid pressure increases, the actuation resistance force generated by the pressure driven actuation resistance mechanism  104  on the sleeve  16  is increased thereby counteracting the force of the collets  40  on the sleeve. Likewise, as the fluid pressure decreases, the actuation resistance force generated by the pressure driven actuation resistance mechanism  104  on the sleeve  16  is also decreased. 
         [0039]    Referring to  FIGS. 10 and 11 , the pressure driven actuation resistance mechanism  104  includes a channel  106  that is in fluid communication with the fluid flow channel  32  of the body  12 . A pressure piston  108  is disposed in the channel  106 , and a ball  110  is disposed in the channel  106  above the pressure piston  108 . An o-ring seal  112  provides a seal between a stem of the pressure piston  108  and the channel  106  to prevent escape of fluid flowing through the fluid flow channel  32 . 
         [0040]    With reference to  FIG. 10 , with the fluid connector  100  not attached and there is no fluid pressure internal to the fluid connector  100 , when the sleeve  16  is retracted the ball  110  is pushed inwardly. With reference to  FIG. 11 , once attachment is made and the fluid connector  100  has internal pressure, the ball  110  is pushed radially outward against an angled interior ramp surface  114  of the sleeve  16  by the pressure piston  108  and the fluid acting on the end of the pressure piston  108  via the channel  106 . The ball  110  creates an actuation resistance force on the sleeve  16  which resists movement of the sleeve  16  to a disconnected position. 
         [0041]    As described above, when the connector  100  has internal pressure, the fluid acts on the piston  18  which directly acts upon the collets  40 , forcing the collets  40  outward which, due to the relatively shallow angle of the collet surfaces  90 , creates an axial force on the sleeve  16  tending to force the sleeve  16  backward to the retracted position. The axial force on the sleeve  16  is translated into a radial force on the ball  110  via the angled interior ramp surface  114  of the sleeve  16 . That radial force is pushing directly against the outward force acting on the pressure piston  108  by the fluid pressure internal to the fluid connector  100 . The two opposing forces should counteract one another to a sufficient extent to prevent a pressure induced retraction of the sleeve  16  when the fluid connector  100  is pressurized. In one embodiment, the two opposing forces can be generally equal to each other. 
         [0042]    With the described pressure driven actuation resistance mechanism  104 , no spring, elastic element or other biasing element acts on the ball  110  that biases the ball  110  downward to the position shown in  FIG. 10 . Instead, the angled ramp surface  114  on the interior of the sleeve  16  forces the ball downward when the fluid connector  100  is not pressurized and the sleeve  16  is pulled back to the retracted position. 
         [0043]    Although the pressure driven actuation resistance mechanism  104  has been described as having a ball  110 , other actuation resistance force producing elements can be used. Any element, such as a ball, a cylinder, or the like, can be used as long as the element can create sufficient actuation resistance force on the sleeve  16  and that permits the element to roll or slide along the ramp surface  114  when the sleeve  16  is retracted. In addition, the pressure piston  108  and the ball  110  need not be separate elements but could instead form a single piece that performs the functions of both the pressure piston and the ball. 
         [0044]    In addition, any of the individual features of the fluid connectors in  FIGS. 1-11  can be used together in any combination thereof. 
         [0045]    The examples disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.