Quick-connect system for a high pressure connection

A quick-connect system for a high pressure connection includes a port and a collet. The port defines an inlet opening at an outer longitudinal end of the port and includes an inner wall having a first sloped surface at least partially defining a collet cavity. The first sloped surface has a first diameter at a first end nearest the inlet opening and a second diameter, which is greater than the first diameter, at a second end opposite the first end. The collet includes a head portion and a plurality of legs extending distally from the head portion, and each leg of the plurality of legs includes a distal foot portion. In a connected state, the foot portions of the plurality of legs are located in the collet cavity, and the foot portions define an outermost diameter that is greater than the first diameter.

TECHNICAL FIELD

The disclosure relates to tube connection systems, and more particularly to high-pressure quick-connect tube connection systems.

BACKGROUND

Air conditioning systems are currently commonplace in homes, office buildings and a variety of vehicles including, for example, automobiles. Over time, the refrigerant included in these systems becomes depleted and/or contaminated. As such, in order to maintain the overall efficiency and efficacy of an air conditioning system, the refrigerant included therein may be periodically replaced or recharged.

Portable carts, also known as recover, recycle, recharge (“RRR”) refrigerant service carts or air conditioning service (“ACS”) systems, are used in connection with servicing refrigeration circuits, such as the air conditioning unit of a vehicle. The portable machines include hoses coupled to the refrigeration circuit to be serviced. A vacuum pump, compressor, and a series of valves operate to recover refrigerant from the vehicle's air conditioning unit, flush the refrigerant, and subsequently recharge the system from a supply of either recovered refrigerant and/or new refrigerant from a refrigerant tank.

Each ACS unit includes many tube and/or hose assemblies which interconnect a manifold block and various other components. A vast majority of the tube and hose assemblies are connected to the manifold block and various other components with some variation of a female nut and a mating male fitting. Installation of each connection often requires an open-face wrench to tighten the female nut until a requisite torque specification is achieved. Although the female nut and mating male fitting often yield sufficient performance in the presence of the high pressure fluids in the system, the time required to assemble the female nut and mating male fitting results in increased manufacturing and maintenance time. In some instances, the assembly time of each tube or hose end has been is estimated to be in excess of fifteen seconds, which, when summed among all the fittings in the ACS unit, contributes to manufacturing time and labor cost.

Certain “quick-connect” fittings are utilized in the pneumatic field to reduce the time required to connect various tubes and hoses. One such fitting10is depicted inFIG. 1, and includes a body12having external threads14for connection to a manifold (not shown) or some other receiving structure, and defines an internal passage16. A collet18is positioned within one end of the body12in the passage16, and includes teeth20configured to engage the outer surface of a tube or hose (not shown). A sealing O-ring22is positioned in the passage16of the body12, and is separated from the collet18by a plastic back ring24.

In order to connect a tube or hose (not shown) with the fitting10, the tube or hose is inserted through an end opening26, which is defined in the collet18, until the tube or hose protrudes far enough into the passage16that the end of the tube or hose contacts a step28of the body12. The plastic back ring24engages an outer surface of the teeth20of the collet18to maintain the teeth20in pressing engagement with the outer surface of the tube or hose, thereby providing a holding force sufficient to hold the tube in place.

If the tube or hose is pulled, the back ring24cooperates with the outer surface of the teeth20to press the teeth inward, thereby providing an increase in the holding force sufficient to prevent the tube or hose from being pulled out of the passage16. In order to remove tube or hose, the collet18is pressed until an end face30of the collet18contacts an end face32of the body12. Pressing the collet18moves the teeth to a position in which the outer surface of the teeth20can no longer engage the plastic back ring24, allowing the tube or hose to be freely pulled out of the passage16without the teeth pressing inward on the tube or hose.

Although previous quick-connect fittings, such as the fitting10, provide for connecting and removal of the tube or hose in a timely manner, the fittings are not intended for high-pressure applications such as those encountered in ACS units. Previous quick-connect fittings are rated for pressures well under 1000 psi, while ACS units often require fittings capable of withstanding pressures in excess of 2500 psi.

In high-pressure applications, for example, the quick-connect fitting10fails due to the high-pressure on the back end of the O-ring22forcing the O-ring22to press against the teeth20of the collet18. By pressing against the teeth20of the collet18, the O-ring22may tear, causing leaks, or the collet18may buckle, causing the tube to release violently from the fitting. Moreover, since the plastic back-ring24is not fluid-tight and is not capable of withstanding the high-pressures of an ACS unit, the mere presence of the back ring24does not eliminate the problems of the prior art quick-connect fitting10.

A connection system for connecting tube and hose assemblies that withstands high-pressure performance requirements and reduces assembly time is therefore desirable.

SUMMARY

A quick-connect system for a high pressure connection comprises a port and a collet. The port defines an inlet opening at an outer longitudinal end of the port and includes an inner wall having a first sloped surface at least partially defining a collet cavity. The first sloped surface has a first diameter at a first end nearest the inlet opening and a second diameter, which is greater than the first diameter, at a second end opposite the first end. The collet includes a head portion and a plurality of legs extending distally from the head portion, and each leg of the plurality of legs includes a distal foot portion. In a connected state, the foot portions of the plurality of legs are located in the collet cavity, and the foot portions define an outermost diameter that is greater than the first diameter.

In one embodiment the quick-connect system further comprises a tube inserted in the collet in the connected state. A maximum width of the foot portion of each leg in a radial direction is greater than a minimum distance between an outer diameter of the tube and the first end of the first sloped portion.

In some embodiments, the foot portion of each leg includes a retaining element configured to engage a tube positioned in the collet.

In another embodiment, of the quick-connect system, the foot portion of each leg includes a first foot sloping surface which slopes outwardly from a distal portion of the first foot sloping surface to a proximal portion of the first foot sloping surface. The first foot sloping surface is configured to engage the first sloped surface as the collet is moved longitudinally outwardly from the connected state so as to urge the retaining element of each leg radially inwardly.

In yet another embodiment, the inner wall further comprises a second sloped surface extending from the outer longitudinal end of the port toward the first sloped surface, and a first cylindrical portion extending longitudinally from the second sloped surface to the first end of the first sloped surface.

In further embodiments of the quick-connect system, the foot portion of each leg includes a second foot sloping surface which slopes inwardly from a distal portion of the second foot sloping surface to a proximal portion of the second foot sloping surface. The second foot sloping surface cooperates with the second sloped surface of the inner wall when the collet is inserted into the inlet opening so as to deform the plurality of legs radially inwardly.

In one embodiment, the quick-connect system further comprises a sealing element positioned in the port and configured to seal between the inner wall and a tube positioned in the port. The port includes a projection projecting radially inwardly from the inner wall, the projection interposed between the sealing element and the collet cavity.

In one particular embodiment, the projection has an inner diameter that substantially corresponds to an outer diameter of the tube.

In another embodiment, the port includes a tube stop face longitudinally inwardly of the sealing element and configured to engage a terminal end face of the tube.

In a further embodiment according to the disclosure, an air conditioning service system comprises a manifold block including a port defining an inlet opening at an outer longitudinal end of the port and including an inner wall having a first sloped surface at least partially defining a collet cavity. The first sloped surface has a first diameter at a first end nearest the inlet opening and a second diameter, which is greater than the first diameter, at a second end opposite the first end. The air conditioning service system further comprises a collet including a head portion and a plurality of legs extending distally from the head portion, and each leg of the plurality of legs includes a distal foot portion. A tube is inserted in the collet and connected to the port of the manifold block. In a connected state, the foot portions of the plurality of legs are located in the collet cavity, and the foot portions define an outermost diameter that is greater than the first diameter.

In some embodiments of the air conditioning service system, a maximum width of the foot portion of each leg in a radial direction is greater than a minimum distance between an outer diameter of the tube and the first end of the first sloped portion.

In another embodiment of the air conditioning service system, the foot portion of each leg includes a retaining element configured to engage the tube.

In one embodiment, the foot portion of each leg includes a first foot sloping surface which slopes outwardly from a distal portion of the first foot sloping surface to a proximal portion of the first foot sloping surface. The first foot sloping surface is configured to engage the first sloped surface as the collet is moved longitudinally outwardly from the connected state so as to urge the retaining element of each leg radially inwardly.

In yet another embodiment of the air conditioning service system, a sealing element is positioned in the port and is configured to seal between the inner wall and the tube. The port includes a projection projecting radially inwardly from the inner wall, and the projection is interposed between the sealing element and the collet cavity.

In further embodiments, the projection has an inner diameter that substantially corresponds to an outer diameter of the tube.

In another embodiment according to the disclosure, an air conditioning service system comprises a manifold block and a tube connected to the manifold block via a quick-connect system. The quick-connect system comprises a port defining an inlet opening at an outer longitudinal end of the port and including an inner wall having a first sloped surface at least partially defining a collet cavity. The first sloped surface has a first diameter at a first end nearest the inlet opening and a second diameter, which is greater than the first diameter, at a second end opposite the first end. The quick-connect system further comprises a collet including a head portion and a plurality of legs extending distally from the head portion, and each leg of the plurality of legs includes a distal foot portion. In a connected state, the foot portions of the plurality of legs are located in the collet cavity, and the foot portions define an outermost diameter that is greater than the first diameter.

In one embodiment, a maximum width of the foot portion of each leg in a radial direction is greater than a minimum distance between an outer diameter of the tube and the first end of the first sloped portion.

In some embodiments, the foot portion of each leg includes a retaining element configured to engage the tube and a first foot sloping surface which slopes outwardly from a distal portion of the first foot sloping surface to a proximal portion of the first foot sloping surface. The first foot sloping surface is configured to engage the first sloped surface as the collet is moved longitudinally outwardly from the connected state so as to urge the retaining element of each leg radially inwardly.

In another embodiment of the air conditioning service system, the quick-connect system includes a sealing element positioned in the port and configured to seal between the inner wall and the tube. The port includes a projection projecting radially inwardly from the inner wall, and the projection is interposed between the sealing element and the collet cavity.

In one embodiment, of the air conditioning service system, the projection has an inner diameter that substantially corresponds to an outer diameter of the tube.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of the embodiments described herein, reference is now made to the drawings and descriptions in the following written specification. No limitation to the scope of the subject matter is intended by the references. This disclosure also includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the described embodiments as would normally occur to one skilled in the art to which this document pertains.

FIG. 2is an illustration of an air conditioning service (“ACS”) system100. The ACS system100includes a housing104in which a refrigerant container or internal storage vessel (“ISV”)108, a controller112, a compressor116, and one or more manifold blocks (only the lower manifold block120is visible inFIG. 1). Hose connections124(only one is shown inFIG. 2) protrude from the housing104to connect to an A/C system and facilitate transfer of refrigerant to and from the ACS system100.

The ISV108is configured to store refrigerant for the ACS system100. No limitations are placed on the kind of refrigerant that may be used in the ACS system. As such, the ISV108is configured to accommodate any refrigerant that is desired to be collected. In some embodiments, the ISV108is particularly configured to accommodate refrigerants that are commonly used in the A/C systems of vehicles (e.g., cars, trucks, boats, planes, etc.), for example R-134a, CO2, or R1234yf. In some embodiments, the ACS system has multiple ISV tanks configured to store different refrigerants. Each independent ISV in one embodiment includes a separate scale and temperature sensor. In other embodiments, the independent ISV tanks are all weighed by a single ISV scale.

Further details of the ACS system100are described with reference toFIG. 3, which is a schematic diagram of the ACS system100ofFIG. 2.FIG. 3depicts a bulkhead manifold124, a top manifold128, the lower manifold120, and the ISV108of the ACS system100. The bulkhead manifold124has a high-side service hose132with a high-side coupler136and a low-side service hose140with a low-side coupler144. The high-side and low-side service hoses132,140, respectively, are configured to attach to high-side and low-side service ports of an air conditioning system, and each of the service hoses132,140is connected to a respective hose connection114(FIG. 1). The bulkhead manifold124routes the high-side service hose132to a high-side bulkhead hose148and the low-side service hose140to a low-side bulkhead hose152. The high-side and low-side bulkhead hoses148,152each connect the bulkhead manifold124to the top manifold128.

The top manifold128and the lower manifold120include various valves, conduits, and other components used in refrigerant recovery and recharge operations. The top manifold128is connected to the lower manifold120by a manifold connection tube156, which is configured to carry high pressure refrigerant between the top manifold128and the lower manifold120. In addition, the lower manifold connects to a compressor suction tube160, which connects to the suction side of the compressor116, a compressor discharge tube164, which connects to the high-pressure side of the compressor116, and a compressor oil return tube168, which connects to an oil return side of the compressor116. A tank vapor hose172fluidly connects the lower manifold120to the ISV tank108to transfer recovered and compressed refrigerant vapor to the ISV tank108, while a charge line176fluidly connects the ISV tank108to the top manifold128to transfer refrigerant through a charge circuit back and into the air conditioning system.

In various embodiments, some or all of the tubes and hoses132,140,148,152,156,160,164,168,172,176are fluidly coupled to the associated manifold120,124,128and/or the ISV108with a quick-connect system200, depicted inFIG. 4. The quick-connect system200includes a port204and a collet208configured to selectively secure a tube212, which is, for example, the manifold connection tube156, to a passage216defined through the port204. In the embodiment shown, the port204is integrally formed in the manifold block220and is, for example, machined directly into the manifold block220, which is, in this example, the lower manifold block120. In other embodiments, the port204is a separate component inserted into the manifold block220.

While reference is made in this illustration to the manifold connection tube156connecting to the lower manifold120, the reader should appreciate that, in various embodiments, the quick-connect system200is implemented as any or all of the connections between the hoses or tubes132,140,148,152,156,160,164,168,172,176with an associated manifold120,124,128or other component of the ACS system100, for example the ISV108. In one embodiment, for example, the manifold connection tube156is connected to the upper manifold128with the quick-connect system200. In other embodiments, for example, each of the tubes132,140,148,152,156,160,164,168,172,176are connected to a respective manifold120,124,128with the quick-connect system200.

Moreover, while the port204is shown as machined directly into the manifold220of the ACS system100, in other embodiments, the port204is machined into a manifold of another RRR cart or ACS system. In yet other embodiments, instead of being machined directly into a manifold, the port204is instead housed in a standalone fitting that can be secured to a manifold or other receiving element. In one specific embodiment of a standalone fitting, the port is embodied with an externally machined straight hex fitting, while in another embodiment, the standalone fitting is an elbow, such as a brass elbow.

Referring back toFIG. 4, the collet208includes a plurality of circumferentially spaced flexible legs224(two are shown inFIG. 4) extending axially, or distally, from a head228of the collet208. The end of each flexible leg224opposite the head228includes a foot230having a retaining element232configured to engage the surface of the tube212. In some embodiments, the retaining elements232are formed as teeth. An outer surface of the foot230includes an outwardly sloped surface234and an inwardly sloped surface232. The outwardly sloped surface234slopes outwardly in a direction from the head228toward the end of the legs224(i.e. slopes outwardly from a proximal end of the outwardly sloped surface234to a distal end of the outwardly sloped surface234), while the inwardly sloped surface236slopes inwardly from the end of the outwardly sloped surface234toward the end of the legs224(i.e. slopes inwardly from a proximal end of the inwardly sloped surface236to a distal end of the inwardly sloped surface236). The head228and the legs224define a passage240sized to accommodate the tube212. The legs224are inserted into the passage216of the port204, as explained in detail below.

With continued reference toFIG. 4, the passage216is defined by an inner surface244of the port204, which extends inwardly from an inlet opening246of the port. The inner surface244includes a sloped inlet wall portion248that is sloped or slanted radially inwardly from an inlet face252, which surrounds the inlet opening246, to a first through wall portion256. The through wall portion256in the embodiment shown extends longitudinally along the passage216to a sloped interior wall portion260. The outer surfaces of the main portion of the two legs224of the collet228located radially opposite each other, as illustrated inFIG. 4, have a diameter that is less than, or approximately equal to, the diameter of the first through wall portion256. However, the outer surfaces of the two feet230of the respective legs224shown define a diameter that is greater than the diameter of the first through wall portion256. As will be discussed in detail below, this arrangement facilitates locking the legs224within the port204.

The sloped interior wall portion260is sloped or slanted radially outwardly from the first through wall portion256to a second through wall portion264. The port204includes a projection268extending inwardly at the end of the second through wall portion264opposite the sloped interior wall portion260such that the second through wall portion264extends longitudinally to a front face272of the projection268. The portion of the passage216extending from the inlet face252to the front face272of the projection268defines a collet cavity276in which the legs224of the collet208are received.

The inner surface244of the port204continues inwardly into the port204and defines a seal notch280bounded by the rear face284of the projection268, an outer face288of the inner surface244, and a rear circumferential face292of the inner surface244. The notch280is sized to accommodate a sealing element296. In the embodiment shown, the sealing element296is an elastic O-ring formed of rubber or another desired elastomer. In other embodiments, the sealing element296is another desired seal or gasket. The inner and outer diameters of the sealing element296and the outer diameter of the tube212are selected such that the sealing element296provides a desired compression against tube212when the tube212is inserted into the port204in order to achieve a fluid-tight seal between the inner surface244of the port204and the outer surface of the tube212.

With continued reference toFIG. 4, the inner surface244of the port204continues inwardly into the port204to define a longitudinally extending rear portion300and a through portion304. In the embodiment shown, the diameter of the longitudinally extending rear portion300is larger than the diameter of the through portion304to form a step that defines a tube stop face308. When the tube212is installed, an end face312of the tube212engages the tube stop face308.

Operation of the quick-connect system200is discussed with reference toFIGS. 4-12. First, the collet208is installed by forcing the legs224of the collet208into the collet cavity276, as shown inFIGS. 6-8. As previously mentioned, the diameter defined by the outer surfaces of the feet230is greater than the diameter of the first through wall portion256of the port204. Thus, with reference toFIG. 6, as the feet230are initially inserted, a sufficient force must be applied to the head228of the collet208in the direction indicated by arrow316to cause the inwardly sloping surface236of the feet230to cooperate with the sloped wall portion248of the inner surface244to force the legs224to flex radially inwardly, thereby providing enough clearance for the feet230to enter the passage216of the port204at the first through wall portion256.

As illustrated inFIG. 7, continued application of a force to the head228in the direction indicated by arrow316results in longitudinal translation of the collet208rearward as the legs224remain flexed, and the outer surfaces of the feet230remain in contact with first through wall portion256. Once the collet208is pushed far enough so that the feet230enter the open space defined by the sloped interior wall portion260and the second through wall section264, as illustrated inFIG. 8, the legs224return to their unflexed position.

After the collet208is installed, or positioned in a connected state, as seen inFIG. 9, the tube212is inserted into the passage216of the port204until the end face312of the tube212engages the tube stop face308. The sealing element296forms a tight seal between the outer surface of the tube212and the inner wall244of the port204at the outer face288. The retaining elements232of the collet208are forced into contact with the outer surface of the tube212. In some embodiments, the outermost retaining elements232define a diameter less than the outer diameter of the tube212. As the tube212is inserted into the port204, the engagement of the outer diameter of the tube212with the retaining elements232causes the legs224of the collet208to flex, which in turn causes interference between the retaining elements232and the angled surface260of the port204. This interference, illustrated inFIG. 10, causes the retaining elements232to apply a force radially inward on the tube212to hold the tube212in place when axial force is applied to the tube168.

The quick-connect system200prevents unwanted release of the tube212from the port204. When the system is in the position ofFIG. 10, if the tube212is pulled away from the port204, the outer surface of the feet230, specifically the outwardly sloping surface234, cooperates with the sloped portion260of the inner wall244to flex the legs224of the collet208radially inwardly, increasing the holding force applied by the retaining elements232acting radially inwardly on the tube212. As the force urging the tube212from the port204increases, the gripping force provided on the tube212by the retaining elements232also increases due to the radially inwardly acting force exerted by the sloped portion260on the retaining elements232. As a result, the retaining elements232prevent removal of the tube212from the port204due to forces urging the tube212away from the port204.

The collet208is designed such that the flex of the legs224causes the retaining elements232to apply a desired holding force on the tube212. In some embodiments, the materials and shape or size of the tube212and the collet208are selected such that the retaining elements232dig into, or slightly deform, the outer surface of the tube212in order to retain the tube212in place when the tube212is urged out from the port204. In other embodiments, the desired holding force is achieved without deformation of the outer surface of the tube212.

Turning toFIG. 11, to release the tube212from the port204, the head228of the collet208is pressed into the port204, in the direction indicated by arrow316, until the head is flush against the inlet face252, thereby positioning the feet230within the open space of the collet cavity276defined between the outer surface of the tube212and the second through wall section264, out of contact with the sloped interior wall portion260. Additionally, in some embodiments, pushing the collet208inwardly results in the retaining elements232of the feet230disengaging from indentations formed in the tube212by the retaining elements232. With the head228held flush against the inlet face252, the tube212may be pulled out of the passage216of the port204without having the feet230contacting the sloped interior wall portion260. With the feet230out of contact of the sloped interior wall portion260, the legs224cannot flex inwardly to apply any additional holding force to the tube212. As a result, the tube can be completely removed, as shown inFIG. 12.

Returning toFIG. 4, with the tube212fully installed in the port204, a fluid connection is established between the tube212and the through portion304of the port204. Due to the pressure of the fluid, some fluid may enter the space between the exterior surface of the tube212and the rear portion300of the port212. However, the sealing element292forms a fluid tight seal between the outer surface of the tube212and the outer face288of the port204, preventing flow of pressurized fluid in a direction towards the inlet face252past the sealing element296.

Unlike conventional quick-connect designs that fail under high-pressure, the quick-connect system200is rated for high-pressure, including pressures exceeding 2500 psi, due to, at least in part, the projection268located between the sealing element296and the collet208. The projection268isolates the sealing element296from the collet cavity276. In contrast to conventional designs, the projection268acts as a barrier that, even under high-pressure, prevents the sealing element296from being urged by pressurized fluid towards the collet208. As a result, the sealing element296is not forced into contact with the collet208because. If the sealing element296is pushed or deformed by the pressurized fluid, the sealing element296is pressed harmlessly against the projection268. Not only does this arrangement prevent the sealing element296from being damaged by the collet208, but the collet208is also prevented from buckling because the sealing element296cannot be forced into contact with the collet208. Consequently, even in high pressure applications, the quick-connect system200of the present disclosure retains the tube212securely in the manifold block220.

In the embodiment shown inFIGS. 4-12, the tube212is embodied as a cut end of a copper tube, and lacks any additional fitting. However, other tubes and fittings may be secured by the port204, including end fittings such as barbed end fittings made of brass or other materials, plastic tubes or hoses, steel tubes, metal tubes, rubber tubes or hoses, or any other desired tube, hose or fitting. In one embodiment, illustrated inFIGS. 13 and 14, the tube212is a brass barbed end fitting320. As shown inFIG. 14, the end fitting320includes an insertion region324and a barbed region328separated by a ring332. A passage336is defined through the length of the fitting320. The barbed region328is configured to retain the tube or hose340(shown inFIG. 13). The insertion region further includes a notch344and a chamfered end348for easy insertion into the port204.

In some embodiments in which the tube212is too hard for the retaining elements232to dig into, for example in the brass barbed end fitting320, the tube212includes a notch, for example notch344, in which the retaining elements232are seated when the tube212or end fitting320is installed. When the insertion portion324of the end fitting320is inserted into the port204, the retaining elements232grip into the notch344or overlap the notch344to hold the fitting in place. In yet other embodiments, instead of a notch344, end fitting320includes a ring or other retaining structure protruding from the surface to cooperate with the retaining elements232.

The quick-connect system of the present disclosure provides many benefits over prior quick-connect fittings. Specifically, the system200can be used in high-pressure applications without experiencing failure due to the pressure in the system forcing the tube to disconnect. Embodiments of the quick-connect system of the disclosure prevent failure of the sealing element and collet, and unwanted tube removal that results from prior designs in high-pressure applications.

Furthermore, the quick-connect system200substantially reduces assembly time of high-pressure RRR refrigerant service carts and ACS systems by reducing the time required to connect the tubes and/or hoses to the manifold block and various other components. While each female nut and mating female fitting connection in conventional ACS systems could require in excess of fifteen seconds to assemble, the quick-connect system200reduces the assembly time to two seconds or less. Furthermore, during service of the ACS systems, the tubes can be easily removed and quickly reinstalled, reducing the time required to maintain the ACS systems.

It will be appreciated that variants of the above-described and other features and functions, or alternatives thereof, may be desirably combined into many other different systems, applications or methods. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements may be subsequently made by those skilled in the art that are also intended to be encompassed by the foregoing disclosure.