WO2022260766A1

WO2022260766A1 - Compression fitting for electrical feedthrough in marine vessels

Info

Publication number: WO2022260766A1
Application number: PCT/US2022/025928
Authority: WO
Inventors: Rustom JEHANGIR; Adam Simko; Eldin MILLER-STEAD; James Chang; Joseph LUDKA; Ryan BURROW
Original assignee: Blue Robotics Inc.
Priority date: 2021-06-07
Filing date: 2022-04-22
Publication date: 2022-12-15

Abstract

A compression fitting for an electrical feedthrough of a marine vessel includes a fitting body having an internal through-passage extending along a longitudinal axis between a forward end and an opposite rearward end of the fitting body; a stop disposed in the internal through-passage between the forward and rearward ends; a seal disposed in the internal through-passage axially forward of the stop; and a compression member having an internal through-passage. The compression member is configured to be received by the fitting body at the forward end to align the respective through-passages. The compression fitting is configured such that an electrical conduit is receivable through the through-passage of the compression member and into the through-passage of the fitting body to extend across the seal and engage the stop, the stop being configured to restrict further axial movement of the electrical conduit, and the compression member being configured to compress the seal in an assembled state to thereby enable sealing against the conduit for restricting ingress of water to the rearward end of the fitting body when the compression fitting is in use.

Description

COMPRESSION FITTING FOR ELECTRICAL FEEDTHROUGH IN MARINE VESSELS

RELATED APPLICATIONS

The application claims the benefit of U.S. Provisional Application No. 63/197,824 filed June 7, 2021, the entire disclosure of which is hereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a compression fitting, and more particularly to a compression fitting that can seal an electrical feedthrough in a marine vessel, and even more particularly to such compression fitting for passing a soft-jacketed electrical cable in a harsh environment exposed to high pressures, such as those found deep underwater.

BACKGROUND

Compression fittings are commonly used to create a watertight passage through a barrier of a marine vessel for passing electrical conduits. Such compression fittings typically include a fitting body coupled to the barrier through which the electrical conduit passes, an elastomeric seal that seals against the cable, and a compression nut that compresses and loads the seal. These respective parts of the fitting are configured to prevent ingress of water across the vessel barrier.

There are two general types of electrical conduits and corresponding types of compression fittings for electrical feedthroughs. The first type is for an electrical conduit made of rigid tubing. In this first type compression fitting, the rigid tubing is generally incompressible and thus only the elastomeric seal is compressed and deformed in a fully-assembled state. This type of compression fitting is available with a variety of ingress ratings, with commercially available products often rated to high pressures, such as 690 bar.

The second type of electrical conduit is made of a soft-jacketed and flexible material, such as polyurethane, which directly covers and contains the electrical wires therein. With this type of electrical conduit, the compression fitting compresses and deforms both the soft-jacketed conduit and elastomeric seal in a fully-assembled state. This type of compression fitting is available with a variety of ingress ratings, with most available products rated to relatively low pressures, such as 1 bar to 10 bar.

SUMMARY An aspect of the present disclosure provides improvements in the water sealing and pressure-resistance capabilities of compression fittings for marine vessels.

More particularly, according to an aspect, the present disclosure provides a unique compression fitting for an electrical cable feedthrough across a water barrier of a marine vessel in which the compression fitting is capable of resisting high pressures found deep underwater. According to some aspects, the unique compression fitting may be particularly suitable for improving the pressure resistance in feedthrough connections of conventional soft-jacketed electrical cables, while also providing an easy to manufacture design at low cost.

According to an aspect, a compression fitting for an electrical feedthrough of a marine vessel, includes: a fitting body having an internal through-passage extending along a longitudinal axis between a forward end and an opposite rearward end of the fitting body; a stop disposed in the internal through-passage between the forward and rearward ends; a seal disposed in the internal through-passage axially forward of the stop; and a compression member having an internal through-passage, the compression member being configured to be received by the fitting body at the forward end to align the respective through-passages; wherein the compression fitting is configured such that an electrical conduit is receivable through the through-passage of the compression member and into the through-passage of the fitting body to extend across the seal and engage the stop, the stop being configured to restrict further axial movement of the electrical conduit, and the compression member being configured to compress the seal in an assembled state to thereby enable sealing against the conduit for restricting ingress of water to the rearward end of the fitting body when the compression fitting is in use. The following description and the annexed drawings set forth certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features according to aspects of the invention will become apparent from the following detailed description when considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The annexed drawings, which are not necessarily to scale, show various aspects of the invention.

Fig. 1 is an exploded isometric view of an exemplary compression fitting according to an embodiment of the present disclosure.

Fig. 2 is an exploded side view of the compression fitting in Fig. 1. Fig. 3 is a side view of the compression fitting in Fig. 1 shown in a fully-assembled state.

Fig. 4 is a cross-sectional side view of the compression fitting shown in Fig. 3.

Fig. 5 is an enlarged cross-sectional side view taken from the section 5-5 in Fig. 4, in which the exemplary compression fitting is shown installed on an exemplary water barrier of a marine vessel.

PET ATT, ED DESCRIPTION

The principles and aspects of the present disclosure have particular application to compression fittings for passing soft-jacketed electrical cables through an electrical feedthrough opening in a water barrier of a marine vessel, and thus will be described below chiefly in this context. It is course understood that the principles and aspects according to the present disclosure may be applicable to other applications where desirable.

Referring to Figs. 1-5, an exemplary compression fitting 10 for an electrical feedthrough of a marine vessel is shown. As shown, the compression fitting 10 generally includes a fitting body 12 having an internal through-passage 14 extending along a longitudinal axis 16 between a forward end 18 and an opposite rearward end 20, a stop 22 disposed in the internal through- passage 14 between the forward and rearward ends, a seal 24 disposed in the internal through- passage 14 axially forward of the stop 22, and a compression member 26 having an internal through-passage 28, in which the compression member 26 is configured to be received by the fitting body 12 at its forward end 18 to align the respective through-passages 14, 28 and enable passthrough of an electrical conduit 30 (also referred to as an electrical cable). As will become apparent in the following description, the compression fitting 10 is configured such that the electrical conduit 30 is receivable through the through-passage 28 of the compression member 26 and into the through-passage 14 of the fitting body 12 to extend across the seal 24 and engage the stop surface 22. The stop 22 is configured to restrict further axial movement of the electrical conduit 30, which enables the compression fitting 10 to improve the sealing and pressure resistance to greater underwater depths. The compression member 26 is configured to compress and load the seal 24 in an assembled state, which thereby enables sealing against the conduit for restricting ingress of water to the rearward end 20 of the fitting body 12 during use of the fitting 10 underwater.

The compression fitting 10 may be used on any suitable marine vessel where it is desirable to provide an electrical passthrough connection having improved sealing and pressure resistant capabilities. In exemplary embodiment, the marine vessel is a marine vehicle. The marine vehicle may be a submersible vehicle, and more particularly may be an underwater unmanned robotic vehicle. The water barrier on which the fitting 10 is employed may be any suitable structure of the marine vessel where water may be contained on one side of the barrier and where ingress of water is prevented to the opposite side. This may include a bulkhead of the vessel, a hull of the vessel, a buoyancy or ballast device of the vessel, an underwater submersible electric thruster of the vessel, an actuator of the vehicle (such as a gripper), a light of the vessel, a sensor of the vessel (such as a camera, leak sensor, sonar, temperature, pressure or depth sensor), GPS, power sources (such as batteries), communication systems (such as modems, cellular, Bluetooth or the like), an electrical enclosure of the vessel (such as for containing one or more of the above-noted electrical devices), or the like. The compression fitting 10 may be provided with such vessels and/or devices which may be later combined or added to a marine vessel. The foregoing are examples, and the various uses of the compression fitting 10 are not limited to these examples. As such, an exemplary barrier 32 is shown in Fig. 5, which is an arbitrary barrier that contains water to one side (water side 34) and prevents water intrusion to the other side (non-water side 36).

The fitting body 12 may be any suitable structure that is adapted to operatively interface with the barrier 32 of the marine vessel (or component thereto). In the illustrated embodiment, the fitting body 12 includes threads 38 toward its rearward end 20 for being threadedly received in a receiver of the barrier 32 (or component thereto). The threads 32 may be of any suitable type, such as standard NPT threads, which may be modified as desired for the particular size desired for the application.

To provide suitable external sealing of the fitting body 12 with the barrier 32, the fitting body includes a face seal 40 (e.g., elastomeric O-ring seal) disposed in a seal groove in a face 42 of the fitting body 12. The threads 38 are on a projecting portion of the fitting body 12 that extend beyond the face 42, such that threading of the fitting body 12 into the receiver of the barrier 32 (or component) enables compression of the seal 40 to seal against the interface between the face 42 and barrier 32. In exemplary embodiments, the fitting body 12 is formed as a female body having a receptable at its forward end 18 for receiving a corresponding male member (e.g., projection, such as a nose or nipple) of the compression member 26. The fitting body 12 and compression member 26 may operatively interface with each other by any suitable means for providing the compressive loading of the seal 24. In the illustrated embodiment, the fitting body 12 includes radially inward threads 44 that threadedly engage with radially outer threads 46 of the compression member 26 to forcible draw these members together to thereby compress the seal 24. The respective outer surfaces of the compression member 26 and fitting body 12 may include flats, such as in a hexagonal structure, to enable a tool, such as a wrench, to provide the force needed to achieve a fully assembled state of the fitting 10.

The compression member 26 may be any suitable structure that is adapted to operatively interface with the fitting body 12 to align the through-passages 14, 28 and provide compression to the seal 24. In exemplary embodiments, the compression member 26 is formed as a cap, nut, plug, union, or the like, having the through-passage 28 for enabling the conduit 30 to pass therethrough. As shown, the through-passage 28 may be a straight axial bore that is coaxial with the through-passage 14 and which enables ease of sliding the conduit 30 through the compression member 26. In the illustrated embodiment, an end face 48 of the compression member 26 engages the seal 24 to provide compressive load to the seal 24 which deforms the seal 24 and enables sealing to the radially outer surface 49 of the conduit 30. The amount of compressive load applied to the seal 24 may be a preload force, and the seal 24 may be further energized and deformed by pressure on the water side 34 when submerged. To prevent over compression of the seal 24, the compressive member 26 may have a stop surface 50, such as an axially facing surface, which limits the travel of the compression member 26 relative to the fitting body 12.

The (internal) seal 24 may be any suitable seal that is configured to interface with the fitting body 12, compression member 26, and conduit 30 to provide suitable sealing functionality that prevents water intrusion to the non-water side 36. The seal 24 may be made of any suitable material, such as a resilient material, for example elastomeric (e.g., nitrile) or the like. As shown, the seal 24 engages a seat 52 in the internal through-passage 14 to prevent movement (e.g., extrusion) further rearwardly by the compression member 26 and water pressure from the water side 34. The seat 52 and corresponding structure of the seal 24 may be any suitable structures for providing such functionality. In the illustrated embodiment, the seat 52 is formed by part of the body 12, but could be formed as an insert to the body 12 which interfaces with another portion of the body. In exemplary embodiments, the seat 52 has a forwardly and radially inwardly facing inclined surface (also 52) that interfaces with a corresponding rearwardly and radially outwardly facing surface 54 of the seal 24. This provides the seal 24 with a conical or frustoconical surface 54 at its rearward side. The seal 24 may have an axially extending portion 56 that fits within an enlarged portion of the internal passage 14 and which connects with the end face 58 of the seal that operatively interfaces against the compression member 26. As shown, the outer surface of the axially extending portion 56 may provide a close fit with the fitting body 12, and the respective inclined surfaces 52, 54 may be substantially complimentary to each other. These respective inclined surfaces 52 enable the seal 24 to be squeezed radially inwardly when compressed from the forward end 58 to thereby provide further sealing force against the conduit

30.

In exemplary embodiments, the seal 24 may include one or more chamfered surfaces at the interface with the compression member 26 (or other operative member therebetween) which are configured to prevent pinching of the seal 24 during assembly. For example, in the illustrated embodiment, the seal 24 includes a radially inner chamfered surface 60 between the end face 58 and a radially inner surface of the seal 24 that engages the conduit 30. The size of the chamfered surface 60 is sufficient to prevent pinching into the radial gap between the compression member 26 and conduit 30, while also enabling sufficient deformation of the seal 24 to provide sealing functionality. In the illustrated embodiment, the chamfered surface 60 is at a 45-degree angle. As shown, the seal 24 also may include a radially outer chamfered surface 62 between the end face 58 and the radially outer surface of the seal 24 that engages the fitting body 12. Again, such chamfered surface 62 may prevent pinching between the compression member 26 and fitting body 12 during assembly.

In exemplary embodiments, the electrical conduit 30 is a flexible polymeric jacket that encases electrical wire(s) 75, which this polymeric jacket may be made of a relatively soft material such as polyurethane or the like. On designs not containing the stop 22, as pressure on the water side 34 increases (e.g., by virtue of greater underwater depths), the polymer jacket material may move or extrude through the internal passage 14 which may damage the wires 75 or expose them to water causing electrical shorts; and/or may deteriorate the sealing functionality of the seal 24 with the conduit 30 therefore allowing intrusion of water to the non-water side 36. In the exemplary fitting 10 design, the stop 22 is configured to restrict or prevent such movement of the conduit 30 (e.g., extrusion of the polymer jacket), which therefore enhances the water sealing and pressure-resistance capabilities of the fitting 10. For example, conventional compression fitting designs without a stop 22 and that are used with soft-jacketed cables are typically rated to relatively low pressures, such as about 1 bar to 10 bar (about 1 to 10 meters water resistant); whereas the exemplary fitting 10 with the stop 22 used with soft-jacketed cables is capable of providing a leakproof connection at high pressures, such as up to about 95 bar (about 950 meters).

The stop 22 of the fitting 10 may be any suitable structure at any suitable location within the internal passage 14 that is configured to restrict axial movement of the conduit 30 beyond the stop 22. For example, the stop 22 may be formed as part of the fitting body 12 (as shown), or may be formed by an insert, such as a sleeve, cap, or the like that interfaces with the fitting body 12. In exemplary embodiments, the stop 22 is configured to engage an end face 65 of the conduit 30 (e.g., polymer jacket), which enables the electrical wire(s) 75 passing through the conduit 30 to continue through the barrier 32 to make their electrical connection. In the illustrated embodiment, the stop 22 is formed as an axially forwardly facing surface of the fitting body 12 that is perpendicular to the longitudinal axis 16, and which is adapted to engage the corresponding end face 65 of the conduit 30, which also may be essentially perpendicular to the longitudinal axis 16. The stop 22 (also referred to as stop surface 22) may be sized relative to the size of the fitting body 12 and diameter of the conduit (e.g., jacket) to provide the desired stop functionality. By way of example, and not limitation, the radial depth of the stop 22 may be in a range from 50% to 100% of the thickness of the conduit 30 (e.g., thickness of the jacket material). As used herein, “operative connection,” or a connection by which entities are

“operatively connected,” is one in which the entities are connected in such a way that the entities may perform as intended. An operative connection may be a direct connection or an indirect connection in which an intermediate entity or entities cooperate or otherwise are part of the connection or are in between the operatively connected entities. An operative connection or coupling may include the entities being integral and unitary with each other, unless otherwise described.

It is to be understood that terms such as “top,” “bottom,” “upper,” “lower,” “left,”

“right,” “front,” “rear,” “forward,” “rearward,” and the like as used herein may refer to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference. It is to be understood that all ranges and ratio limits disclosed in the specification and claims may be combined in any manner. It is to be understood that unless specifically stated otherwise, references to “a,” “an,” and/or “the” may include one or more than one, and that reference to an item in the singular may also include the item in the plural.

The term "about" as used herein refers to any value which lies within the range defined by a variation of up to ±10% of the stated value, for example, ±10%, ± 9%, ± 8%, ± 7%, ± 6%, ± 5%, ± 4%, ± 3%, ± 2%, ±1%, ±0.01%, or ±0.0% of the stated value, as well as values intervening such stated values.

The phrase “and/or” should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

The word “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” may refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”

The transitional words or phrases, such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” and the like, are to be understood to be open- ended, i.e., to mean including but not limited to.

Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a "means") used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.

Claims

CLAIMS: What is claimed is:

1. A compression fitting for an electrical feedthrough of a marine vessel, comprising: a fitting body having an internal through-passage extending along a longitudinal axis between a forward end and an opposite rearward end of the fitting body; a stop disposed in the internal through-passage between the forward and rearward ends; a seal disposed in the internal through-passage axially forward of the stop; and a compression member having an internal through-passage, the compression member being configured to be received by the fitting body at the forward end to align the respective through-passages; wherein the compression fitting is configured such that an electrical conduit is receivable through the through-passage of the compression member and into the through-passage of the fitting body to extend across the seal and engage the stop, the stop being configured to restrict further axial movement of the electrical conduit, and the compression member being configured to compress the seal in an assembled state to thereby enable sealing against the conduit for restricting ingress of water to the rearward end of the fitting body when the compression fitting is in use.

2. The compression fitting according to claim 1, wherein the stop is formed as an internal surface of the fitting body, or is an insert to the fitting body.

3. The compression fitting according to claim 1, or any other preceding claim, wherein the stop has a surface that is perpendicular to the longitudinal axis and is configured to engage an end face of the conduit.

4. The compression fitting according to claim 1, or any other preceding claim, wherein the seal includes a chamfer between an end face that engages the compression member and a radially inner surface configured to engage the conduit.

5. The compression fitting according to claim 1, or any other preceding claim, wherein the chamfer is about 45-degrees.

6. The compression fitting according to claim 1, or any other preceding claim, wherein the seal includes a chamfer between an end face that engages the compression member and a radially outer surface that engages a radially inner surface of the fitting body.

7. An electrical feedthrough assembly for a marine vessel, comprising: an electrical conduit comprising a flexible polymeric jacket that encases electrical wires; a fitting body having an internal through-passage extending along a longitudinal axis between a forward end and an opposite rearward end of the fitting body; a stop disposed in the internal through-passage between the forward and rearward ends; a seal disposed in the internal through -passage axially forward of the stop; and a compression member having an internal through-passage, the compression member being configured to be received by the fitting body at the forward end to align the respective through-passages; wherein the electrical conduit extends through the through-passage of the compression member and into the through-passage of the fitting body to extend across the seal and engage the stop, the stop being configured to restrict further axial movement of the electrical conduit, and the compression member being configured to compress the seal in an assembled state to thereby enable sealing against the conduit for restricting ingress of water to the rearward end of the fitting body when the compression fitting is in use.

8. The electrical feedthrough assembly according to claim 7, wherein the stop is configured to engage an end face of the jacket of the conduit.

9. A marine vehicle comprising the compression fitting according to any preceding claim.

10. A method of assembling an electrical feedthrough connection of a marine vessel, comprising: providing the fitting according to any preceding claim; providing an electrical conduit comprising a flexible polymeric jacket that encases electrical wires; feeding the electrical conduit into the fitting such that the jacket engages the stop and the electrical wires pass through the remainder of the fitting.