Non-metallic Fluid Couplings

Abstract

A non-metallic fluid coupling having a current transfer element incorporated therein is disclosed. The coupling is formed of two C-shaped halves of a non-metallic, non-conductive material, each half including a living hinge and latch or a hinge and latch made of a common material with the C-shaped halves. A non-metallic, substantially rigid sealing sleeve may be incorporated into the coupling to seal the coupling while maintaining its strength.

Description

[Technical field]

[0001] The present invention relates generally to coupling assemblies, and more particularly to non-metallic fluid coupling assemblies that utilize a sealing sleeve. [Background technology]

[0002] Coupling assemblies are used in fluid systems within several industries, such as the aerospace industry. Types of fluid systems include, but are not limited to, fuel or water waste systems within aircraft. Because these systems consist of multiple tube assemblies that allow fluid movement, the tube assemblies must be joined together with coupling assemblies that must create a reliable seal, allow minimal flexibility within each coupling, and allow electrical current to flow from one tube to the next. Without a proper seal, leakage can occur, potentially causing catastrophic failure, for example of fuel or flammable liquids. Current flow requires static electricity to dissipate to prevent sparks from occurring within or adjacent to the fluid system.

[0003] The fittings in these systems are formed with two fluid tubes mechanically attached to a ferrule adapter, a clamshell fitting, a sealing sleeve or body, and two seals such as an O-ring. First, the O-ring is placed in a circumferential groove on the ferrule adapter. Then, the sealing sleeve or body is slid over both O-rings. The interface between the O-rings and the sealing sleeves provides a fluid seal in the radial direction. A clamshell fitting is placed around the ferrule adapter to prevent the ferrule adapter from pulling apart axially. The interface of the O-rings on the ferrule adapter and the groove that receives the retainer half body lip on the fitting provides a seal in the axial direction. This fitting can be held in a closed position due to a hinge and latch mechanism installed on the fitting.

[0004] Historically, coupling assemblies have been constructed from metallic materials, which are relatively heavy and susceptible to corrosion over time, and which can pose problems for the lightning protection capabilities of the aircraft. Summary of the Invention [Means for solving the problem]

[0005] The present invention is directed to a fitting and a sealing sleeve for the entire fitting assembly.

[0006] The present invention is comprised of components made from non-metallic materials, such as plastics, composites, polymers, fiberglass, or combinations of the same or similar materials. For example, the retainer halves can be made from PEEK with the same interface dimensions as the existing metallic joint. The sealing sleeve or body can also be made from a non-metallic material, such as fiberglass, with the same interface dimensions as the metal sealing sleeve. Using the same interface dimensions allows for interchangeability between components within a metallic joint assembly and the non-metallic components of the present invention. For example, a metallic joint in an existing metallic joint assembly can be replaced with a non-metallic joint of the present invention, or a metal sealing sleeve in an existing metallic joint assembly can be replaced with a non-metallic (e.g., fiberglass) sealing sleeve as taught herein. Replacing an existing metallic component with a component of the present invention can reduce weight by up to 70% depending on the metal or metal alloy of the replaced component.

[0007] The non-metallic fitting retainer halves have a semi-cylindrical shape, and when the fitting is closed, the fitting assembly forms a nearly complete cylinder. The retainer halves have two lips on opposite sides that are designed to mate with the ferrule adapter lips when the fitting is closed. When the fitting is in the closed position, the inner diameter of the fitting is slightly larger than the outer diameter of the sealing sleeve or body so that the sealing sleeve or body can fit within the fitting both axially and radially.

[0008] A single pin inserted into the hinge may be used to assemble the non-metallic joint retainer halves together. Unlike metallic joints that have many smaller components that assemble into a hinge and latch mechanism, both the hinge and latch of the present invention are integrated into the retainer halves to reduce part count and minimize assembly time. Preferably, the hinge and latch of a non-metallic joint are made from the same material as the retainer halves if not integrally formed. The combination of the integral latch and hinge mechanism allows the joint to open and close like a "scallop".

[0009] The sealing sleeve or body may be manufactured from a non-metallic material, such as fiberglass, and this component provides a seal between two adjacent tubes with a ferrule adapter and an O-ring, respectively. The sealing sleeve is made from a relatively hard material and / or the final manufactured part is hard and has little or no bending. Each ferrule adapter has a circumferential groove formed by an inner lip and an outer lip in which an O-ring can be located. The sealing sleeve has an inner diameter that is slightly larger than the outer diameter of the inner and outer lips of the ferrule adapter, so that the sealing sleeve can be placed over the O-ring and ferrule adapter combination to form a fluid-tight seal. The sealing sleeve provides strength from internal pressure coming from the fluid system in the radial (circumferential) direction. The combination of the O-ring or seal and the fit of the ferrule adapter to the sealing sleeve provide flexibility within each fitting.

[0010] When the fitting is closed around the assembled ferrule adapter, sealing sleeve and O-ring, the lip of the retainer half engages the outer lip of the ferrule adapter, preventing the two separate ferrule adapters and tubes from axially separating.

[0011] One or more electrical contacts are made across the fitting with a mating mechanism that contacts both tubes, allowing current to flow from one tube to the other. Preferably, the mating mechanism is made from a conductive material, including but not limited to metal. The mating mechanism is positioned on the surface of the fitting retainer half in the axial direction to make contact for each tube. The mating device is attached to the retainer half in a way that allows the retainer half's features to hold the mating tabs in place without the possibility of them becoming dislodged. Overmolding and / or sonic welding are examples of manufacturing processes that allow the retainer half to hold the mating tabs in place.

[0012] An advantage of the present invention is that non-metallic fittings and sealing sleeves can be used in existing metallic fitting assembly designs. Prior art fitting designs have attempted to replace ferrule adapters with flexible sealing sleeves that are connected or attached to fluid tubes using adhesives or sealants. However, because these designs do not utilize ferrule adapters and require modifications to the sealing sleeves, the interfaces of such prior art fittings are less compatible than the present invention and present many problems. The present invention allows for compatibility with existing metallic assembly components, including replacing metallic fittings or sealing sleeves with the non-metallic parts of the present invention.

[0013] With a typical metal fitting assembly, the latch and hinge mechanism may be made from different materials due to the number of components involved. The present invention incorporates the latch and hinge mechanism into the retainer halves, which may be made from the same material as the retainer halves. The hinge and latch mechanism is incorporated into the retainer halves via injection molding or similar manufacturing process. This improvement results in fewer parts and quicker assembly time. Additionally, the present invention relies on the natural flexibility of non-metallic materials to latch / unlatch the fitting without metal springs, and preferably the sealing sleeve flexes little or not at all because the material is not a flexible material. It is the O-ring or seal and the fit between the sealing sleeve and the ferrule adapter that provides the flexibility or movement in the seal of the present invention.

[0014] These and other features of the present invention will be best understood with reference to the accompanying drawings and detailed description of the invention which follow. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is an elevated perspective view of a first embodiment of a fitting of the present invention. [Diagram 2] FIG. 2 is a perspective exploded view of the joint of FIG. 1. [Diagram 3] FIG. 2 is a longitudinal cross-sectional view of the embodiment of FIG. [Figure 4] FIG. 2 is an axial cross-sectional view of the embodiment of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] 1 and 2 illustrate a first embodiment of the invention, including a fluid conduit fitting 10 for mating a first tube 12 to a second tube 14. Each tube assembly 12, 14 is formed with a ferrule adapter 16 that surrounds the end of the tube and is used to mate the tubes together as is known in the art. The fitting 10 is formed by first and second C-shaped halves 20, 22 held together in one circumferential position by a hinge 24 and releasably closed in a second circumferential position by a latch 26. Four equally spaced mating devices 28 are positioned around the fitting, holding each mating in place by bosses 30 on the retainer halves 20, 22 that project outwardly from the outer surfaces of the retainer halves. The latch mechanism 26 can be formed integrally with the second C-shaped half 22 and includes a base 32 with two downward barbed projections 34 extending circumferentially towards the half 20. The halves 20 include shoulders 36 that receive the barbs 34 to latch the second half 22 to the first half 20 as shown. Additionally, the first half 20 may have a single upwardly extending barb 38 extending circumferentially between the barbs 34 through an opening 40 in the base 32 that is captured by a ledge 42. The barbs 34, 38 are secured to each mating opposing half such that the diameter of each half expands, thereby engaging the mating surfaces with greater force. The halves 20, 22 can be easily released by depressing the barbs 38 and lifting the barbs 34 to release contact against the ledge 42 and shoulder 36, respectively. It is understood that other connection types are available and are part of the invention.

[0017] The hinge 24 and latch 26 components can be integrally formed with the halves 20, 22 of the fitting 10 using non-metallic materials that are molded together during manufacture. That is, half 20 can be integrally formed as a single unit with the hinge bearing 44, ledge 36 and upwardly projecting barb 38. Similarly, half 22 can be formed as a single unit with the hinge bearing 46, base 32 and downwardly projecting barb 34. Only the pin 48 is required to complete assembly of the fitting 10.

[0018] FIG. 3 illustrates a first cross-sectional view of the fitting 10 connecting a first fluid tube 12 to a second fluid tube 14 at each ferrule adapter 16 of the tube. Circumferential O-ring grooves 50, 52 are formed in the ferrule adapter 16. Each O-ring groove houses a flexible O-ring (omitted for clarity) that abuts against the ferrule adapter 16 and is compressed by the sealing sleeve to prevent leakage across the seal in a radial direction. The hinge 24 and latch 26 are non-metallic and integral with the fitting halves 20, 22, so there is no electrical path across the fitting that could cause a spark or electrical short. The fitting 10 fits against the outer lip and sealing sleeve 54 of the ferrule adapter 16 to capture and seal against the mating tube, providing a seal in the axial direction. This configuration allows some flexing by the O-ring seal as well as the fit of the sealing sleeve, O-ring and fitting. A seal is formed in the sealing sleeve 54 that abuts against the O-ring seal located on the ferrule adapter 16 to prevent leakage in a radial direction. In this way the joint is sealed radially and axially while still allowing some flexure of the joint.

[0019] FIG. 4 illustrates a side view of the fitting 10 illustrating the living latch 26 and living hinge 24. Each half 20, 22 can be manufactured from a non-metallic material, such as plastic, composite, polymer, fiberglass, or a combination of the same or similar materials. For example, the halves 20, 22 can be made from PEEK with the same interface dimensions as an existing metallic fitting. The sealing sleeve 54 and the halves 20, 22 can also be made from a non-metallic material, such as fiberglass, with the same interface dimensions as a metallic sealing sleeve. The same interface dimensions allow for interchangeability between components within an existing metallic fitting assembly with a replacement non-metallic fitting. For example, a metallic fitting in an existing metallic fitting assembly can be replaced with a non-metallic fitting of the present invention, or a metallic sealing sleeve in an existing metallic fitting assembly can be replaced with a fiberglass sealing sleeve as taught in the present invention.

[0020] 4 as having a semi-cylindrical or C-shaped shape, and when fitting 10 is closed, the fitting assembly has a nearly complete cylindrical shape. When fitting 10 is in the closed position as shown, the inner diameter of fitting 10 may be slightly larger than the outer diameter of sealing sleeve 54 so that the sealing sleeve 54 can fit axially and radially within the fitting.

[0021] The non-metallic joint retainer halves 20, 22 may be assembled together using a single pin 48 inserted into the hinge 24 at the mating structure 44, 46. Unlike metallic joints that have many smaller components assembled into the hinge and latch mechanism, both the hinge 24 and latch 26 of the present invention are integrally incorporated into the retainer halves and formed as a single unit to reduce part count and minimize assembly time. In another embodiment, the hinge 24 and latch 26 of the non-metallic joint 10 are not integral but are made from the same material as the retainer halves 20, 22. The combination of the latch 26 and hinge 24 cooperate to open and close the joint 10 like a "scallop". In a preferred embodiment, the hinge and latch are incorporated into the retainer halves, which may or may not be the same as described by the present application.

[0022] The sealing sleeve 54 may be made of a non-metallic material, such as fiberglass, and this component provides a seal between two adjacent tubes 12, 14 with their ferrule adapters 16 and O-rings, respectively. The sealing sleeve 54 is made of a relatively hard material and / or the final manufactured part is hard and has little or no bending. In certain other embodiments, the O-ring may be replaced with another seal. The sealing sleeve 54 has an inner diameter that is slightly larger than the outer diameter of the ferrule adapter lip. The ferrule adapter flange outer and inner lips form a groove in which the O-ring sits adjacent the sealing sleeve 54. The sealing sleeve can then be placed over the O-ring and ferrule adapter 16 combination to form a fluid-tight seal. The sealing sleeve 54 provides strength from the internal pressure coming from the fluid system in the radial (circumferential) direction. The combination of the O-ring or seal and the fit of the ferrule adapter 16 to the sealing sleeve 54 allows for flexibility within each fitting.

[0023] When the fitting 10 is closed around the assembled ferrule adapter 16, sealing sleeve 54 and O-ring of each tube 12, 14, the "C" shaped cross section and flanges prevent the two separate ferrule adapters and tubes from separating axially. The force of the retainer halves 20, 22 against the outer lips of the ferrule adapters provides axial strength along the tube run. The fitting also provides additional sealing in the radial (circumferential) direction.

[0024] The mating features 28 contact the crimped ferrules 16 connected to the tubes 12, 14, allowing electrical current to flow from one tube to the other. The mating features 28 are made from a conductive material, including but not limited to metal. The mating features 28 are positioned on the axial surface of the fitting retainer halves 20, 22 to make contact for each tube. Although shown with four mating features, more or less mating features can be added or subtracted without departing from the scope of the invention. The mating features are attached to each retainer half in a manner that allows the non-metallic material of the fitting 10 to mold over the mating device 28, securing the non-metallic material in place while allowing electrical contact. The retainer halves include extruded bosses 30 that can have various shapes, sizes and amounts that are molded or reshaped over the mating device to hold the mating device in place.

[0025] Although specific embodiments are described and illustrated in this disclosure and drawings, the present invention is not intended to be limited to any specifically described or illustrated embodiments. Rather, those skilled in the art will readily appreciate that many modifications and substitutions may be made within the scope of the described embodiments, and the scope of the present invention is intended to include all such modifications and substitutions. Thus, the scope of the present invention is not limited herein unless expressly specified, and the scope of the present invention is appropriately assessed by the appended claims using their plain and ordinary meaning consistent with the present specification and drawings.

Claims

1. 1. A fluid coupling for connecting first and second fluid pipes, each having a ferrule adapter at a respective mating end, comprising: first and second semi-cylindrical elements cooperating to form a cylindrical joint, the first and second semi-cylindrical elements being formed of a non-metallic material; first and second hinge elements integrally formed on the first and second semi-cylindrical elements, respectively, for establishing pivoting of the first and second semi-cylindrical elements to open and close the joint; a pin passing through the first and second hinge elements; a non-metallic sealing sleeve positioned adjacent the ferrule adapter of each fluid pipe to seal the joint; a plurality of circumferentially equally spaced electrically conductive joining features formed in the fitting, the plurality of electrically conductive joining features adapted to make electrical contact with the first and second fluid pipes when the fitting is in a closed position conducting electricity from the first fluid pipe to the second fluid pipe, the plurality of electrically conductive joining features extending from a first lateral edge of one of the first and second semi-cylindrical elements across an outer surface of the semi-cylindrical elements to an opposing lateral edge of the semi-cylindrical elements; a pair of barbed projections integrally formed on the first semi-cylindrical element configured to bend radially inwardly onto a shoulder of the second semi-cylindrical element; a barb integrally formed on the second semi-cylindrical element configured to bend radially outwardly onto a latch integrally formed on the first semi-cylindrical element between the pair of barbs; Fluid couplings including:

2. The joint of claim 1 , wherein the first and second semi-cylindrical elements are fabricated from a composite material.

3. The fitting of claim 1 , wherein the first and second semi-cylindrical elements are fabricated from a polymer.

4. 2. The fitting of claim 1, wherein said first and second semi-cylindrical elements are made of plastic.

5. The fitting of claim 1 , wherein the sealing sleeve is manufactured from fiberglass.

6. 2. The fitting of claim 1, wherein an outer diameter of the sealing sleeve is smaller than an inner diameter of the semi-cylindrical element such that the sealing sleeve can reside in the fitting in axial and radial dimensions.

7. 2. The joint of claim 1, wherein the joining features are attached to each C-shaped cylindrical element by molding the material used to form the C-shaped cylindrical element over the joining features.

8. The joint of claim 1 , wherein the joint includes only one pin.

9. 2. The fitting of claim 1, wherein the first hinge element is molded with the first semi-cylindrical element and the second hinge element is molded with the second semi-cylindrical element to form first and second integrally formed parts.

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