Quick connect tube coupling

A quick-connect coupling having a tubular tube support, a sleeve and a collet. The tubular tube support includes a tube support portion and a mounting flange joined to the tube support portion. The sleeve includes an inner surface diameter greater than an outer surface diameter of the tube and an outer surface engaging an inner wall of a bore. The collet includes an outer surface engaging the inner surface of the sleeve and an inner surface diameter greater than an outer surface diameter of the tubular tube support and slightly less than the outer surface diameter of the tube. The tube is frictionally retained between the collet and the tubular tube support when the tube is inserted into the coupling.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to quick connect tube couplings, and more particularly to improvements in configurations for such couplings.

2. Description of the Related Art

Quick-connect tube couplings are used to connect flexible tubes in fluid power systems such as, for example, pressured air systems for vehicle air brakes and air conditioning systems, which may involve connections to diverse items such as valve bodies, air tanks and the like. In these and other systems, each flexible tube requires a coupling to connect the end of the tube to a body, such as a conventional fitting, valve, manifold or similar device for transmitting and receiving pressurized fluid. Connecting a tube to a body, or removing a tube from a body, can be a time consuming and expensive task that is frequently performed in the field where specialized tubes may not be readily available.

There are a variety of “push-to-connect” type couplings that permit a tube to be quickly and easily connected to a valve or manifold body without the use of tools. With these couplings, a tube is connected by simply press-fitting the coupling into a bore within the body and then inserting the leading end of the tube into the coupling. Typically, the coupling contains a plurality of components that releasably retain the tube therein.

One known quick-connect coupling design includes a sleeve with a tube support mounted therein, an internal O-ring, an external O-ring and a collet that cooperatively retain the tube on the tube support by engaging the tube with the collet. While this design has proven effective in practice, coupling designers continue to develop improvements in these types of couplings to further minimize manufacturing expense, reduce assembly errors and expedite assembly of the components prior to insertion into a fitting or manifold body.

SUMMARY OF THE INVENTION

A quick-connect coupling is provided that includes a tubular tube support, a sleeve and a collet. In an embodiment of the invention, the tube support includes an outside surface configured to frictionally engage an inner wall of a tube, a tube support portion and a mounting flange joined to the tube support portion. The sleeve includes an inner surface diameter greater than an outer surface diameter of the tube and an outer surface engaging a wall of a bore. The collet includes an outer surface engaging the inner surface of the sleeve and an inner surface diameter greater than an outer surface diameter of the tubular tube support and slightly less than the outer surface diameter of the tube. The tube is frictionally retained between the collet and the tubular tube support when inserted into the coupling. At least one annular sealing member is axially disposed between the tubular tube support and the end of the collet for sealing with the tube, and at least one spacer-member is disposed between the radially extending mounting flange and the annular sealing member. The annular sealing member and spacer member are positioned to form an annular trough between the collet and the tube support portion for receiving the end of the tube. The radially extending mounting flange is fixed to the first end of the sleeve to assemble the components.

In another embodiment of the invention, the quick-connect coupling includes an annular sealing member having a generally rectangular cross-section, which is disposed between the radially extending mounting flange and the end of the collet. The annular sealing member is positioned to form an annular trough between the collet and the tube support portion for receiving the end of the tube.

In another embodiment of the invention, a quick-connect coupling is provided that includes a tubular tube support, a sleeve and a collet. The tubular tube support includes an outside surface configured to frictionally engage an inner wall of a tube. The sleeve includes an inner surface diameter greater than an outer surface diameter of the tube and an outer surface engaging the surface of a bore. The collet includes an outer surface engaging the inner surface of the sleeve and an inner surface diameter greater than an outer surface diameter of the tubular tube support and slightly less than the outer surface diameter of the tube. The tube is frictionally retained between the collet and the tubular tube support. An annular sealing member is disposed between the sleeve and the tube support, and is positioned to sealingly contact an inner surface of the bore and the outer surface of the tube.

A method of manufacturing a quick connect coupling is also provided.

DETAILED DESCRIPTION

Referring now to the drawings, the preferred illustrative embodiments of the present invention are shown in detail. Although the drawings represent some preferred embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated to better illustrate and explain the present invention. Further, the embodiments set forth herein are not intended to be exhaustive or otherwise limit or restrict the invention to the precise forms and configurations shown in the drawings and disclosed in the following detailed description.

Referring now toFIG. 1, there is shown an embodiment of a quick-connect tube coupling20, configured in accordance with the principles of the present invention. In the illustrated embodiment, quick-connect tube coupling20includes a sleeve22, a tube support24, a pair of internal O-rings26and27, an external O-ring28and a collet30. A flexible tube32is received over a tube support portion34of tube support24and is frictionally retained thereon when collet30is slid over tube32.

In an embodiment, sleeve22has a relieved annular end portion36at a first end38thereof, which defines an annular shoulder40. The annular shoulder40supports a radially extending flange42of tube support24. The radial flange42is substantially perpendicular to tube support portion34of tube support24. Unlike prior art couplings, tube support24does not include an L-shaped connecting portion between flange42and tube support portion34. Between internal O-rings26,27and first portion34of tube support24is an annular void44that receives the end of tube32. In the embodiment shown inFIG. 1, tube support24is retained within sleeve22with a roll/coin edge45that engages the end of radial flange42.

Internal O-ring26is positioned to seal against tube32and internal O-ring27rests against radial flange42of tube support24. Internal O-ring27functions as a spacer between internal O-ring26and radial flange42; however, internal O-ring27may also seal against tube32. External O-ring28is received in an annular external groove46in sleeve12proximate a second end48of sleeve22and seals against an inner wall of a bore into which coupling20installed.

Collet30includes an internal gripping surface50, which may include at least one barb or other formation used to frictionally engage tube32. Collet30slides into sleeve22to secure tube32against tube support portion34of tube support24.

The assembly sequence of the coupling embodiment shown inFIG. 1is as follows. Collet30is inserted into sleeve22after insertion of internal O-rings26,27. Tube support24is then installed and staked to sleeve22by virtue of roll/coin edge45. Finally, external O-ring28is inserted into external groove46on sleeve22. The component parts of coupling20remain together after assembly and do not require a plug to keep the component parts assembled

Referring toFIGS. 2 and 3, another embodiment of coupling20is shown. In the embodiment shown inFIG. 2, internal O-ring27is replaced with a spacer insert29. Spacer insert29is shown as having a generally rectangular cross-section; however, other geometric cross-sectional shapes, such as an oval, are also within the scope of the invention. Spacer29may be made of ferrous and non-ferrous metals, plastic, elastomers and may or may not exhibit sealing properties. In the embodiment shown inFIG. 3, internal O-ring26is also replaced with a flexible cup seal31, such as a C-cup seal, or other non-O-ring type annular sealing member.

With reference toFIG. 4, another embodiment of coupling20is shown. In this embodiment, both internal O-rings26,27are replaced with an annular sealing member33. Annular sealing member33functions as both a sealing element to seal against tube32and as a support element to support tube32within void44. In the embodiment shown inFIG. 4, annular sealing member33includes an inner surface having a generally flat interior cylindrical component41and a pair or tapered components43that extend radially outwardly and away from cylindrical component41.

In another embodiment shown inFIG. 5, annular sealing member33is generally rectangular in cross-section and includes a sealing protrusion47, such as an annular dimple, which extends inwardly from an inner surface49. In another embodiment shown inFIG. 6, annular sealing member33includes a generally rounded inner surface51defined by at least one radius R. In still another embodiment shown inFIG. 7, an inner surface53of annular sealing member33is defined by two tapered surface components55that converge at an apex57. Apex57may be defined by a point, as inFIG. 7, or even a flat or radius, for example. It will, however, be appreciated that annular sealing member33is not limited to the embodiments shown inFIGS. 4-7and that other cross-sectional profiles are within the scope of the invention.

Annular sealing member33may be molded from a polymeric material, such as a thermoset elastomer. Alternatively, annular sealing member33may be cut from a blank of polymeric material. For example,FIG. 8illustrates a generally rectangular annular sealing member29whose shape is cut using a lathe or other cutting apparatus, rather than forming the shape in a mold. However, the ultimate profile achieved by cutting a polymeric blank is not intended to be limited to the generally rectangular shape profile shown inFIG. 8and may include the profiles illustrated inFIGS. 4-7, among others.

Referring now toFIGS. 9-13, there is shown another embodiment of a quick-connect coupling60configured in accordance with the principles of the present invention. The quick-connect coupling60includes a sleeve62, a unitary tubular tube support64, an internal O-ring66, an external O-ring68and a collet70. As with the embodiment shown inFIG. 1, the quick-connect coupling60is used to connect a tube72to another component, such as a single step bore, air tank or other bore.

As shown inFIG. 9, sleeve62has a relieved annular end portion76at a first end78thereof that defines a radially outwardly directed annular groove80and a shoulder82. In an embodiment, tube support64includes a generally conical flange84in a pre-installed condition. Conical flange84is connected to the tubular tube support64by a radial flange portion86that includes an axially extending section88and a radially extending section90. Between the axially extending section88and a tube engaging section92of the tube support64is an annular trough94that receives the end of tube72.

As shown inFIGS. 12 and 13, tube support64is retained in sleeve62by expanding flange84into annular groove80. Shoulder82prevents tube support64from progressing too far into sleeve62during expansion and functions as a surface against which flange84is deformed. As shown inFIG. 13, a force is applied to tube support64in the direction indicated by force vector95. Referring toFIG. 10, as the force is applied, the dimension A, generally representing the inside diameter of flange84, decreases to A′ and the dimension B, generally representing the outside diameter of flange84, increases to B′ as flange84is deformed against shoulder82and flattens. Accordingly, as flange84flattens, the outside diameter of flange84expands into groove80to secure tube support64to sleeve62. Optionally, a mandrel96may be employed during deformation of flange84to minimize reduction of the inside diameter of flange84(see, e.g.FIG. 13), ensuring tube72can enter trough94during assembly.

Referring now toFIGS. 14 and 15, there is shown a quick-connect coupling100according to another embodiment of the present invention. The quick-connect coupling100includes a sleeve102, a tubular tube support104, an O-ring106and a collet108. As with the embodiment shown inFIG. 1, the quick-connect coupling100is used to connect a tube110to another component, such as a single step bore, air tank or other bore.

Referring toFIG. 15, coupling100is shown installed in a bore112. When installed in bore112, O-ring116seals against tube110and an inner cylindrical surface114of bore112. In contrast to the embodiment shown inFIG. 1, coupling100eliminates the need for separate O-rings to seal against inner surface114and tube110.

The present invention has been particularly shown and described with reference to the foregoing embodiments, which are merely illustrative of the best modes for carrying out the invention. It should be understood by those skilled in the art that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention without departing from the spirit and scope of the invention as defined in the following claims. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. This description of the invention should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of these elements. Moreover, the foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application.