Asymmetric hose coupling endform for fluid transfer assemblies

Abstract

An endform connector having an axial bore through which a fluid is conveyed comprising: a rigid tubular member having a first end, a second end, an annular channel having an inner diameter extending from the first end to the second end through which a fluid is transported, a stem portion extending a fixed distance from the first end, and at least one sealing member extending outward from the stem portion forming a surface having a tapered profile terminating in an outwardly extending rim, which exhibits an asymmetric perimeter adapted to be inserted into an inner channel of a fluid transport hose, wherein the endform connector is sealed to a fluid transport hose; and a connector portion on the second end adapted to be coupled with a second fluid conveying structure, and a method for assembling an endform connector to a hose are described.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a longitudinal side view of an endform tube connector of the prior art ready for assembly with a hose;

FIG. 2 a is a cross-sectional end view of the endform tube connector of FIG. 1;

FIG. 2 b is a cross-sectional end view of an endform tube connector of the prior art;

FIG. 3 a is a graph illustrating the coupling tensile force of an endform connector of the present invention.

FIG. 3 b is a graph illustrating the coupling tensile force of an endform connector of the prior art.

DETAILED DESCRIPTION OF THE INVENTION

It has been found that a hose endform connector having an arrowhead barb configured to exhibit an asymmetric perimeter rather than a symmetric circular perimeter provides significantly improved tensile values. Furthermore the asymmetric barb exhibits significantly less sensitivity (more robust) to crimp diameter variability, hose dimensional variability, etc., while maintaining an overall equivalent performance with respect to both inside and outside diameter of the hose to which the coupler is assembled as well as exhibiting no increase in push-on force in assembling the endform connector to a hose.

The basic concept of the present invention is to change the shape of the outer perimeter of the arrowhead barb from a symmetrical circular shape to an asymmetric shape by offsetting the shape of the arrowhead barb and creating a larger interference between the stem land diameter and the arrowhead barb diameter. More specifically, the coupling retention is increased using both clamped and crimped assembly design formats, while maintaining equivalent assembly effort force.

The advantage of the asymmetric arrowhead barb design over the conventional symmetrical circular arrowhead barb is as follows:

• • push-on force is not increased.
  • Coupling tensile (axial force) is enhanced up to about 92%.
  • Peak coupling tensile (axial force) is maintained over a wider tolerance.

The potential applications for the endform connectors having the asymmetrical configuration of the present invention include assemblies for automotive and other mechanical applications, such as in power steering, transmission, oil cooler, and other fluid transport assemblies requiring high pressures.

FIGS. 1 and 2 illustrate a hose endform connector of the present invention used to connect an end form connector to a polymeric hose. As shown in FIG. 1, the endform connector 10 includes a tubular body 12 having a first end 14 and a second end 16. An annular channel 18 extends along longitudinal axis X from the first end 14 to the second end 16. The tubular body 12 includes a stem portion 20 and a sealing member 22 adjacent the first end 14 of the tubular body 12. The stem portion 20 and the sealing member 22 are adapted to inserted into an open channel 24 of a hose 26 to secure the hose 26 to the endform connector 10 to provide a leak-free connection. The stem portion 20 has a uniform outer annular surface 28 extending a fixed distance from the first end 14 of the tubular body 12. The sealing member 22 extends outwardly from the outer annular surface 28 of the stem portion 20 to form a radially increasing surface 30 having a tapered profile. The radially increasing surface 30 of the sealing member 22 terminates in a rim 32 exhibiting an asymmetrical perimeter. The sealing member 22 includes a rearward surface 34 lying in a plane perpendicular to or nearly perpendicular to the orientation of the tubular body 12. The rearward surface 34 of the sealing member 22 extends radially outward from the tubular body 12 and terminates with the rim 32 exhibiting an asymmetric perimeter. Typically, the rearward surface 34 may be tapered at an angle of up to about 5°, preferably, about 0 to 3° and most preferably, about 0 to 2°, with respect to the vertical orientation of the rearward surface 34. The stem portion 20 is adapted to be inserted into an open end 24 of a hose 26 to provide a leak-free fitting. FIG. 2 shows a cross-sectional view of the endform connector of FIG. 1, wherein the rim 32 of the sealing member 22 is shown as having an asymmetric configuration while the annular channel 18 of the tubular body has a circular configuration.

When the metal endform connector 10 is inserted into the open end of the hose 26, sufficient pressure is exerted upon the hose 26 to radially compress the hose 26 inward around the stem portion 20 of the end fitting 10 such that the open channel 24 of the hose 26 engages the sealing member 22 providing a leak-free seal in the fuel transport assembly. The sealing members 22 not only provide leak-free seals but they also increase or maintain the pull-off resistance of the hose 26 from the endform connector 10.

The number of sealing members on the endform connector is not critical. One sealing member in the form of an arrowhead barb is sufficient in most application; however, it may be desirable to include more than one sealing member at fixed intervals along the stem portion of the endform connector. In those instances where more than one sealing member is employed, It may be desirable to alter the rotational position of the more than one sealing members to exhibit a non-linear orientation of the asymmetrical rims so that the symmetry of the more than one arrowhead barbs are not in a linear relationship.

The materials used to form the endform connector should be of a low corrosion tolerance material. In one embodiment the endform connector is formed from a metal, such as steel or the like, or it is formed from a ceramic material or a rigid plastic. Such materials should be high quality and free from voids, pits, laps cracks, folds, seams and other defects. It is within the context of the present invention to treat the metal or ceramic endform connectors, especially the arrowhead barbs to protect them from the environment. The endform members may be coated with a polymeric material 36 (FIG. 1) such as nylon, or it may be electroplated, painted or similarly treated. In another embodiment, the endform may be formed completely from a plastic material.

EXAMPLE 1

SAMPLE 1—A first endform connector having an asymmetric shaped arrowhead barb in accordance with the present invention, and a fluid transport hose were assembled to determine coupling tensile values, robust characteristics, and push-on force.

COMPARATIVE SAMPLE 2—A second endform connector having a circular shaped arrowhead barb in accordance with the prior art, and a fluid transport hose were assembled to determine coupling tensile, robust characteristics, and push-on force.

Regarding SAMPLE 1, the prediction trace yields the following insight with respect to coupling tensile performance:

• • Hose 3209 yields higher tensile values than hose 3039.
  • Coupling tensile values drop as hose ID increases.
  • Coupling tensile values drop significantly as the “% compression” of the crimped assembly decreases.
  • Asymmetrical stem and symmetric stem yield approximately equal tensile values at high compression.
  • Symmetric barb is very sensitive to crimp compression as evidenced by the slope of the “% compression” factor traces).

Regarding SAMPLE 2, the prediction trace yields the following insight with regard to the asymmetric coupling tensile performance:

• • Overall equivalent performance of each stem with respect to the following factors: Hose, OD, and ID.
  • The slope of the “% compression” factor is near zero, indicating that the asymmetric stem is much less sensitive (more robust) to crimp diameter variability, hose dimensional variability, etc.

Although the present invention has been fully described in connection with a preferred embodiment thereof and with reference to the accompanying drawings, various changes and modifications will occur to those skilled in the art. Accordingly, such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.

Claims

1. An endform connector having an axial bore for conveying a fluid, said endform connector comprising: a rigid tubular member having a first end, a second end, an annular channel having an inner diameter extending from said first end to said second end providing a path through which a fluid is transported, a stem portion extending a fixed distance from said first end, and at least one sealing member extending outward from said stem portion forming a surface having a tapered profile, said surface having said tapered profile terminating in an outwardly extending rim, said outwardly extending rim exhibiting an asymmetric perimeter adapted to be inserted into an inner channel of one end of a fluid transport hose, wherein said one end of said fluid transport hose is seal ably secured to said to said extending rim exhibiting an asymmetric perimeter; anda connector portion on said second end, said connector portion adapted to be coupled with a second fluid conveying structure.

2. The endform connector of claim 1 wherein said at least one sealing member is an arrowhead barb.

3. The endform connector of claim 1, wherein said at least one sealing member includes an annular surface opposite said tapered surface, said annular surface extending perpendicularly relative to said rigid tubular member.

4. The endform connector of claim 1, wherein said rim exhibiting said asymmetric perimeter has a sharp edge.

5. The endform connector of claim 1, wherein said hose is uniformly deformed onto and around said at least one sealing member to create a leak-free seal therebetween.

6. The endform connector of claim 1 wherein said endform connector is made from a material selected from the group consisting of metal, ceramic and plastic.

7. The endform connector of claim 6, wherein said endform is metal.

8. The endform connector of claim 7, wherein said metal is steel.

9. The endform connector of claim 1, wherein said metal endform connector is pre-coated with a protecting material to protect said endform connector from environmental conditions.

10. The endform connector of claim 9, wherein said protective material is nylon.

11. The endform connector of claim 1, wherein said second fluid conveying structure is a quick connect/quick disconnect coupling.

12. A method for coupling an endform connector to a hose to provide a leak-free seal between said endform connector and said hose wherein said coupling exhibits reduced push-on effort, said method comprising; providing an endform connector, said endform connector comprising: a rigid tubular member having a first end, a second end, an annular channel having an inner diameter extending from said first end to said second end through which a fluid is transported: a stem portion extending a fixed distance from said first end: at least one sealing member extending outward from said stem portion forming a surface having a tapered profile, said surface having said tapered profile terminating in an outwardly extending rim, said outwardly extending rim exhibiting an asymmetric perimeter adapted to be inserted into an inner channel of a fluid transport hose; and a connector portion on said second end, said connector portion adapted to be coupled with a second fluid conveying structure;providing a fluid transport hose having a first end, a second end and an annular inner surface forming an inner channel for transporting a fluid therethrough;inserting said outwardly extending rim exhibiting said asymmetric perimeter into one end of said fluid transport hose; andsealably securing said one end of said fluid transport hose to said outwardly extending rim exhibiting said asymmetric perimeter inserted therein.

13. The method of claim 12, wherein said endform connector is made from a rigid material selected from the group consisting of metal, ceramic or plastic.

14. The method of claim 13, wherein said endform connector is made from metal.

15. The method of claim 14, wherein said metal is steel.

16. The method of claim 12, wherein said sealing member includes an annular surface opposite said tapered surface, said annular surface extending perpendicularly from said rigid tubular member.

17. The method of claim 12, wherein said rim exhibiting said asymmetric perimeter has a sharp edge.

18. The method of claim 12, wherein said endform connector is pre-coated with a protecting material to protect said endform connector from environmental conditions.

19. The method of claim 18, wherein said protective material is nylon.

20. In a method of assembling an endform connector to a hose in a fluid transport assembly, the improvement which comprises: providing an endform connector, said endform connector comprising a steel tubular member having a first end, a second end, an annular channel having an inner diameter extending from said first end to said second end through which a fluid is transported, a stem portion extending a fixed distance from said first end, and at least one sealing member extending outward from said stem portion forming a surface having a tapered profile, said surface having said tapered profile terminating in an outwardly extending rim, said outwardly extending rim exhibiting an asymmetric perimeter having a sharp edge, said tapered surface adapted to be inserted into an inner channel of a fluid transport hose; and a connector portion on said second end, said connector portion adapted to be coupled with a second fluid conveying structure;providing a fluid transport hose having a first end, a second end and an annular inner surface forming an inner channel for transporting a fluid therethrough;inserting said outwardly extending rim exhibiting said asymmetric perimeter into one of said first end and said second end of said hose; andsealably securing said one end of said fluid transport hose to said outwardly extending rim exhibiting said asymmetric perimeter inserted therein.