Underwater mateable and un-mateable electrical connector

A receptacle unit of a connector for sealably engaging and disengaging contacts therein can include one or more closed inner chambers. At least one of the one or more inner chambers being configured to contain a receptacle contact. Each receptacle contact can be configured to engage a plug contact of a plug unit of a connector. A closed cavity can be at least partially in contact with each inner chamber. The closed cavity can contain a deformable material. At least a portion of the closed cavity can be configured to be movable with respect to another portion of the closed cavity to permit balancing of pressure of the deformable material within the closed cavity to pressure outside of the closed cavity.

FIELD OF THE PRESENTLY DISCLOSED TECHNOLOGY

In one embodiment, the presently disclosed technology is an electrical plug and receptacle connector that can be mated and/or unmated underwater, even at the greatest ocean depths. Both the plug and receptacle bodies can be made from elastomeric material, herein referred to simply as rubber.

BACKGROUND

Subsea electrical connectors generally fall into one of two categories. One category consists of connectors that can be mated and/or unmated on the sea surface and then can be submerged, even to great depths. They are called “dry-mate” connectors. The second category is made up of connectors that can be mated and/or unmated either on the surface or underwater. They are called “wet-mateable” connectors. The presently disclosed technology relates to wet-mateable connectors.

The first commercially available wet-mateable connectors were introduced in the 1960's (see, e.g., Nelson, U.S. Pat. No. 3,271,727). Examples of these connectors are manufactured by Cooper Industries of Houston, Tex. and/or Eaton of Cleveland, Ohio. They are “interference-fit” products wherein ring-like plug contacts within a rubber body are separated by rubber segments along a cylindrical shaft. The shaft penetrates a rubber-molded receptacle having a bore wherein respective annular socket contacts are similarly separated by rubber segments. The bore is open on both ends, and when the plug shaft enters, it squeegees water out the opposite end of the receptacle bore as the respective plug contacts move into engagement with those of the receptacle. These rubber-bodied interference-fit connectors are widely used, and are exceptional for many non-critical operations. However, they are not highly reliable and often cannot be unmated at significant water depth. The low reliability can come mostly from traces of seawater that are not cleanly squeeged out of the receptacle bore during mating, thus leaving electrical leakage paths either between adjacent contacts along the bore, or to the external environment. Inability to unmate at depth can arise from the fact that the connector's rubber portions are much more compressible than the metal contacts they surround. Under high pressure the rubber portions are pressed tightly around the contacts, effectively binding the plug shaft within the receptacle bore.

Another type of rubber-molded underwater mateable connector uses a different form of interference fit between the plug and receptacle units. Examples of these connectors are also manufactured by Cooper Industries of Houston, Tex. and/or Eaton of Cleveland, Ohio. In this type, round-section plug pins have extended shafts whose bases are encapsulated by larger diameter cylindrical rubber sleeves from which the conductive pin portions protrude. The respective socket contacts are recessed within rubber cylindrical bores. When a plug pin is fully penetrated into its respective socket, the heavy rubber sleeve of the plug pin forms a sealed interference fit into its respective rubber cylindrical bore. Upon mating underwater, water contained within the recessed socket bore is mostly forced back out of the recess by the entering pin, but some water can remain trapped around the contacts. This second sort of interference-fit connector was introduced commercially by the French company SOURIAU SAS in the 1970's. The fundamental design was never patented. As with the previously described interference-fit connectors, these can have electrical leakage problems and under certain circumstances can be extremely difficult to unmate at high deep-sea pressures.

Both types of interference-fit connectors mentioned above are commercially available from SEACON, COOPER Interconnect, SOURIAU SAS, and a number of other suppliers. None of the prior-art rubber-molded connectors have means, other than trapping environmental fluid, to balance the pressure around the mated contacts to that of the ambient working environment, and hence can have the concomitant problems of high unmating force and electrical leakage.

Commercially available underwater mateable connectors with structures different from those mentioned above can avoid the reliability and unmating problems by reducing the pressure difference between the volume surrounding the mated contacts and the outside environment. These are often referred to as “pressure-balanced” connectors. In these, pin-and-socket contacts are mated in a chamber containing a benign flowable substance that protects them from the external environment. The protective flowable dielectric substance hereinafter referred to simply as “fluid” or “oil” for convenience only, is pressure-balanced to the ambient environment by way of a compensating element, which is typically a movable portion of the chamber wall. Connectors of this sort have elongated pins whose shafts are coated to isolate the conductive portions from the environment, and have electrically conductive contact tips of substantially the same diameter as the coated pins. The tips extend beyond the protective coating. When mating, the pins enter the fluid-filled chamber by way of penetrable passages through an end-seal. The end-seal passages can seal the chamber from the outside environment before, during, and after mating and de-mating. Once mated, the conductive pin-tips are completely immersed within the benign contact chamber fluid, leaving at most a small portion of the protected shafts exposed to the in-situ environment.

Some connectors in the above category have blade-like pins, for example (U.S. Pat. Nos. 3,653,207 and 9,263,824); others have pins with rounded cross sections as in (U.S. Pat. Nos. 4,373,767, 4,948,377; 5,271,158; 5,655,442, 7,285,003 and pending U.S. application Ser. No. 16/111,790). All of the receptacles in these fluid-filled connectors have oil chambers with elastomeric end-seals which can permit the plug pins to sealable enter and withdraw from the chambers during mating and unmating.

SUMMARY

Relative to the presently disclosed technology, all prior-art oil-filled and pressure-balanced connectors comprise many more separate components. The presently disclosed technology provides an over-molded, pressure-balanced, fluid-filled, wet-matable connector that can be more economically built than prior-art pressure-balanced products without sacrificing any of their reliability.

All rubber-molded underwater-mateable connectors available commercially can be impossible or at least difficult to disconnect at great ocean depths, and can be unreliable due to electrical leakage paths. Currently available fluid-filled and pressure-balanced underwater mateable connectors do not have those problems, but are more expensive than their rubber-molded counterparts, and they incorporate significantly more components. The complexity and expense of prior-art fluid-filled and wet-mateable underwater connectors put them out of reach of many, if not most, harsh environment projects. There are many applications in which it would be desirable to have low-cost, simple, rubber-molded connectors that can avoid the aforementioned problems by being fluid-filled and pressure-balanced, but without the high part-count. The presently disclosed technology fulfills that and other needs.

Embodiments of the presently disclosed technology described herein provide for an apparatus which can include a first connector unit (hereafter called the “plug”) and a second connector unit (hereafter called the “receptacle”), which can be repeatedly connected and disconnected underwater or in other harsh environments without loss of integrity. The described embodiments are intended for use subsea, but could be used in myriad applications, for example wherein pin and socket contacts, when connected, must remain sealed from each other and from the in-situ environment; and when disconnected, the receptacle contacts must still remain isolated from each other and from the in-situ environment.

In embodiments of the presently disclosed technology, the plug or a plug unit can house one or more electrical “pins,” which can include elongated, cylindrical, insulated shafts with exposed electrically-conductive tips. The receptacle or a receptacle unit can house a respective one or more electrical “sockets” housed in one or more fluid-containing or oil-filled chambers sealed from the exterior environment. When the plug and receptacle units are joined, the one or more plug pins can sealably penetrate respective one or more resilient passages into the receptacle, their conductive tips thereby joining the respective one or more socket contacts within the one or more fluid-containing or oil-filled chambers. The receptacle contacts within the fluid or oil chamber can remain sealed from the outside environment before, during, and/or after mating and demating of the plug and receptacle units. At least a portion of each closed chamber can be configured to be movable with respect to another portion of the closed chamber to permit balancing of pressure within the closed chamber to pressure outside the closed chamber.

DETAILED DESCRIPTION

Certain terminology is used in the following description for convenience only and is not limiting. The words “forward” and “rearward” (and derivations thereof) designate directions in the drawings to which reference is made. Unless specifically set forth herein, the terms “a,” “an” and “the” are not limited to one element but instead should be read as meaning “at least one.” Furthermore, the terminology used herein includes at least two types of elastomers. One is a strong, waterproof, elastic substance made from natural ingredients or alternately produced chemically. In everyday usage it is called rubber, and is referred to as such throughout this description. One other elastomer referred to throughout this description is elastomeric gel. It is a soft, highly viscoelastic polymer substance. Elastomeric gels have elastic restoring forces which distinguish them from flowable, low viscosity gels which have little or no elasticity. Skin care gels, for instance, are flowable, whereas gels used in shoe sole inserts are not flowable; they are elastomeric. The terminology includes the words noted above, derivatives thereof and words of similar import.

FIGS. 1 and 2are perspective views of a three-circuit embodiment of the presently disclosed connector illustrating respectively plug or plug unit1(sometimes referred to as the “first unit”), and receptacle or receptacle unit2(sometimes referred to as the “second unit”). Molded rubber plug body3can include frontal bore4. Molded rubber body5of receptacle unit2can consist of two parts: forward portion5a, and rearward portion5b. Frontal bore4of plug body3can be sized and/or shaped to receive in approximate axial alignment at least a portion of forward portion5aof molded body5of receptacle2. Material, such as fluid, liquid and/or gas (e.g. air), from the surrounding environment that is displaced by the entrance or movement of forward portion5aof receptacle2into plug bore4can be vented out of bore4via one or more vent ports or holes6, and can also be vented back out of bore4via the radial interface between bore4and forward portion5aof receptacle2. Forward protruding radial ribs9, and central forward protruding nib10on face11of receptacle forward portion5akeep receptacle face11of receptacle2from forming a sealing engagement with face12of plug unit1when plug unit1and receptacle unit2are fully engaged. Raised axial rib13on forward portion5aof receptacle body5in cooperation with axial rib14on plug body3can provide both visual and tactile indicators that aid in rotationally aligning units1and2when connecting the units.

FIG. 3illustrates one embodiment of plug1in partial axial half-section. Plug body3can be made from rubber that is over-molded onto cable20, onto one or more individual electrical conductors21, and onto rearward portion23of one or more plug contacts or plug pins24. Optionally, each plug contact24consists of rearward portion23, shaft25, and tip26. Substantial portions of plug contacts24can be included in body3of plug unit1. External surfaces of the various elements molded within rubber plug body3can be treated in routine ways, for example as by the application of bondable Chemlok substrates provided by Lord Corporation, such that they are both sealed and mechanically bonded within rubber plug body3. Optionally, conductors or wires,21are mechanically and electrically attached by routine means such as by soldering or crimping to recesses (not shown) in rearward portions23of plug contacts24.

Portions28of plug body3can extend outward along shafts25of plug contacts24(e.g., functioning as a sleeve) while leaving conductive tips26of plug contacts24exposed. Shafts25of plug contacts24can be coated with dielectric substrate29prior to overmolding, thereby providing a second, or redundant, electrically insulating barrier between conductive shafts25and the outside environment.

Inwardly protruding (and optionally annular) nib30of elastomeric plug body3can seat into complementary groove31of receptacle unit2when units1and2are fully engaged, thereby providing some force to retain the two units in connected position when mated. When units1and2are fully engaged, forward face34of plug unit1can butt against face35of receptacle unit2. Tapered molded rubber portion37of plug body3can aid in mechanically attaching plug body3to cable20, and can provide some bending strain relief at the junction of cable20and plug body3.

FIG. 4shows one embodiment of receptacle unit2in partial half-section, andFIG. 5shows a complementary view of unit2which is exploded axially. Receptacle rearward portion5bcan be made from rubber that is over-molded onto cable41, onto one or more individual electrical conductors42, and onto rearward portion45of one or more receptacle contacts46. Optionally, each receptacle contact46consists of rearward portion45, shaft48, and socket49. Substantial portions of receptacle contacts46can be included in rearward portion5bof molded body5of receptacle unit2.

As with plug unit1, the surfaces of elements molded within rubber receptacle rearward portion5bcan be treated in routine ways, for example as by the application of bondable Chemlok substrates provided by Lord Corporation, such that they are both sealed and mechanically bonded within elastomeric receptacle rearward5b. Optionally, conductors or wires42are mechanically and electrically attached by routine means such as by soldering or crimping to recesses (not shown) in rearward portions45of receptacle contacts46.

In one embodiment, plug contacts24and receptacle contacts46are radially distributed at angles within plug unit1and receptacle unit2, respectively, such that the units can be connected in only one rotational orientation.

Forward portion5aof receptacle unit2, illustrated inFIGS. 4 and 5, and again inFIG. 6, can be molded from rubber. At least a substantial part of inner surface50of forward portion5aof receptacle unit2can be bonded, e.g., post-mold bonded, onto wall52of receptacle rearward portion5b, for example utilizing bondable Chemlok agents provided by Lord Corporation, such that they are both sealed and mechanically bonded together. Tapered portion53of receptacle rearward portion5bcan both (i) aid in mechanically attaching rearward5bto cable41, and (ii) provide some bending strain relief at the junction of cable41and receptacle rearward portion5b.

When assembled onto receptacle rearward portion5b, surface55of receptacle forward portion5acan butt against surface56of receptacle rearward portion5b. Optionally, in the final assembly of receptacle unit2, surfaces52and56of receptacle rearward portion5bare sealably bonded respectively to surfaces50and55of receptacle forward portion5a.

As shown inFIGS. 4 and 5, receptacle contacts46protrude outwardly or forwardly from a remainder of rearward portion5b. Sleeves60can extend forwardly from face57of rearward portion5bencapsulating rearward portions45of receptacle contacts46. When receptacle forward portion5aand rearward portion5bare assembled together, rear body sleeves60can sealably engage bores62in forward portion5a. The forward ends of bores62are sealed by resilient end-seals64. When receptacle forward and rearward portions5a,5bare assembled together, bores62become completely closed inner chambers65(as shown inFIG. 4).

Inner chambers65can be sealably penetrable through end-seals64. Inner chambers65can be filled with a flowable dielectric material66, hereinafter referred to simply as fluid or oil. At least a portion of radial walls63defining bores62can be elastically deformable in response to minor pressure differences across them, and thus can substantially balance the pressure of fluid66within bores62to the pressure outside of walls63. When plug unit1and receptacle unit2are mated, at least a tip of plug pins24can sealably penetrate respective receptacle chamber end-seals64to engage respective receptacle sockets49in their respective inner chamber65. The volume of fluid66displaced by entering plug pins24is accommodated by deformable radial walls63of bores62.

Rearward portion45of each receptacle contact46can be fixed within receptacle rearward portion5b, into which they can be sealably bonded. Sockets49on the forward ends of receptacle contacts46can extend into forward extensions70(seeFIG. 5) of inner chambers65of receptacle forward portion5ainto which sockets49can also be bonded. Being thus fixed on one end into receptacle rearward portion5b, and on the other end into receptacle forward portion5a, receptacle contacts46can act as struts which can stiffen receptacle unit2against bending, torsion, and axial compression and extension.

Entrance chambers71can be formed within or can be in fluid communication with forward extensions70of bores62. Entrance chambers71are configured to communicate with and/or receive at least some of fluid66from inner chamber65through ports or holes72in the bases of receptacle sockets49. Prior to the mating of units1and2, each of inner chambers65, respective bore62, and respective entrance chamber71, form a continuous volume of fluid66.

FIG. 7is a partial axial cross-sectional view of mated units1and2including a view of tip26of plug pin24engaged with and/or received by receptacle socket49. As plug pin24enters end-seal64, a small portion73of end-seal64can be extruded and/or move into entrance chamber71of respective bore62. When plug unit1and receptacle unit2are fully mated, an inward facing ring-like seal75in each respective forward extension70of forward portion5acan form a secondary seal between forward portion5aand respective overmolded portion28of plug-pin shaft25of plug pin24, thereby sealing entrance chamber71.

Ring-like or second seal75can provide a light interference fit to overmolded portion28of plug-pin shaft25, such that some leakage past second seal75can occur in the presence of pressure differences between the fluid in first chamber or entrance chamber71and the fluid in second chambers or inner chamber65. The leakage past ring-like seal75can insure that entrance chamber71can replenish any loss of fluid by drawing as needed from inner chamber65. When units1and2are fully mated, there can be at least two axial elastomeric seals (i.e., end-seal(s)64and ring-like seal(s)75), and at least two fluid chambers (e.g., entrance chamber(s)71, and inner chamber(s)65), between sockets49and the outside environment.

Resilient end-seals64shaped to sealably receive cylindrical plug contacts26in the presently described embodiment can be of the tap-and-bore construction disclosed in U.S. Patent Application Publication No. 2018-0193627, which is incorporated herein in its entirety as a reference. Those skilled in the art will recognize that other contact and end-seal combinations could equally well be used in the presently disclosed technology. For example, either the cylindrical-contact, spring-and-stopper construction of U.S. Pat. No. 5,203,805, or the slit-and-blade construction of U.S. Pat. No. 9,263,824 could be used, which are each incorporated herein in their entirety as a reference.

As noted, when receptacle forward portion5aand rearward portion5bare assembled, sealed inner chambers65are formed. In at least one embodiment, sealed or closed cavity80, best seen inFIGS. 4, 5, and 7, is also formed when receptacle forward portion5aand rearward portion5bare assembled. Cavity80is sealed on its forward end by wall81of receptacle forward portion5a, and on its rearward end by wall57of receptacle rearward portion5b. The outer radial wall of cavity80is defined by wall82of receptacle forward portion5a. Cavity80is sealed from inner chamber(s)65by wall(s)63of inner chamber(s)65. Walls63of fluid-filled inner chamber(s)65can form at least a portion of the walls defining cavity80. Cavity80can, thus, be at least partially in contact with, and optionally at least partially or completely surround, each inner chamber65.

During the assembly of receptacle forward portion5aand rearward portion5b, cavity80can be filled with elastomeric gel85which exhibits sufficient elastic deformability to balance pressure changes within inner chamber(s)65, to the pressure outside of receptacle unit2. Elastomeric gel85can be a preformed elastomeric gel, optionally with a bulk modulus close to that of the rubber molded portions of receptacle unit2.

It is known in prior art to fill the contact mating chambers of pressure-balanced underwater connector receptacles with flowable gels, as for example in U.S. Pat. No. 3,522,576 and others. If these prior-art gels were not flowable they would not be able to move freely out of electrical or optical sockets, and therefore would impede coupling of plug and receptacle contacts. Elastomeric gels would not be suitable for filling the contact mating chambers of pressure balanced underwater connector receptacles because they would impede coupling of the pin-and-socket electrical contacts. Although the use of flowable gels is known in prior art, the use of elastomeric gels in pressure-balanced underwater connectors is not known in the prior art.

Gel85in the presently disclosed technology can be a low-durometer elastomeric gel, such as those available through many manufacturers, including but not limited to GelSmart LLC. Gel85can be easily deformable in order to substantially balance pressure changes within inner chamber(s)65to the pressure outside of receptacle unit2. Pressure changes within fluid-filled inner chamber(s)65can cause slight deformations of chamber wall(s)63. The deformations of chamber wall(s)63create deformations of gel85, which can be passed on to the external environment via elastomeric outer wall82of receptacle forward portion5a, which can flex inward and/or outward slightly to compensate for the deformations. As shown inFIG. 5, gel85can be pre-formed to substantially or completely fill cavity80, and can be inserted into cavity80during the assembly of receptacle unit2.

Gel85within cavity80can facilitate balancing pressure differences between the outside environment and fluid66within fluid-filled inner chamber(s)65of receptacle unit2. Gel85can transmit outside environment pressure variations from outer wall82to wall(s)63of each inner chamber65while still keeping receptacle unit2sufficiently firm for normal handling (e.g., to function as intended with plug unit1). A flowable gel would not provide the required firmness. Elastomeric gel85and the aforementioned rigid receptacle contacts46cooperate to reduce deformations of unit2. For extremely rough handling, for instance such as might occur when units1and2are manipulated by remotely operated vehicles, one or both of units1and2can be protected by rugged, rigid shells (not shown).

The foregoing discussion illustrates that the presently disclosed technology provides a reliable connector embodying multiple levels of protection for the circuits from each other and from the in-situ environment, while doing so with an uncomplicated and economical construction. In one embodiment, the presently disclosed technology can house the receptacle contacts within flexible fluid chambers which, in turn, can be at least partially enclosed within a chamber containing an easily deformable substance, such as elastomeric gel. The chambers which house the contacts can have relatively simple, redundant closure means to keep them sealed from the outside environment. Optionally, every conductive element of the mated plug and receptacle units is at least doubly sealed from the harsh working environment. Compared to prior-art connectors, the simplicity of the presently disclosed technology makes it relatively economical without sacrificing integrity.

In one embodiment, the presently disclosed technology is directed to a method of engaging the one or more second contacts of the connector receptacle to the one or more first contacts of the connector plug and/or disengaging the one or more second contacts of the receptacle of the connector from the one or more first contacts of the plug of the connector. The method includes sealably inserting at least a portion of one of the first contacts of the plug through a resilient end-seal of the receptacle and into the at least one receptacle inner chamber such that the first contact engages one of the second contacts within the inner chamber. Optionally, the method can further include subsequently sealably withdrawing the first contact from the inner chamber thereby allowing closure of the resilient end-seal.