1. Field of the Invention
The present invention relates generally to optical and electro-optical connectors for use in harsh environments such as subsea environments, and is particularly concerned with a flush and fill tool or apparatus and method for removing old optical fluid from the optical contact chamber or chambers of such connectors and replacing the removed optical fluid with clean optical fluid.
2. Related Art
There are many types of connectors for making electrical and fiber-optic cable connections in hostile environments. One type includes connectors for undersea mating and de-mating. Such underwater connectors typically comprise a first connector or receptacle unit containing one or more receptacle contacts and a second connector or plug unit containing an equivalent number of plug contacts or contact pins or probes for engagement with the receptacle contacts on mating engagement of the units. Typically, the contacts are contained in a sealed chamber containing dielectric fluid or optical fluid, and the probes enter the chamber via one or more normally sealed openings. One problem in bulkhead optical or electro-optical connector units is sand, silt or debris infiltration into the optical manifold and chamber during mating and demating of the connector units. Another issue is exceeding the recommended mate/demate count for the connector.
A number of different sealing mechanisms have been proposed in the past for releasably sealing subsea connector units during demating. One such sealing mechanism has an opening into the contact chamber which comprises an elastomeric tubular entrance surrounded by an elastomeric sphincter which pinches the entrance closed upon itself when the plug and receptacle units are in an unmated condition. In the mated condition, the sphincter pinches against the entering probe to form a seal. Other Underwater electro-optical connectors are described in U.S. Pat. Nos. 4,616,900 and 4,666,242 of Cairns. In U.S. Pat. No. 4,666,242, the male and female connector units are both oil filled and pressure balanced. This device utilizes a penetrable seal element having one or more openings which pinch closed when the units are separated. Other connectors have rotating seal elements which rotate between closed and open positions during mating to open seal openings and allow contact probes to enter the receptacle contact chamber or chambers on mating.
So called rolling seal connectors, such as the connector described in U.S. Pat. No. 6,017,227 of Cairns et al., are harsh environment or underwater connectors in which dielectric fluid filled contact chambers in the plug and receptacle units are sealed at the forward ends of the connectors by rolling seals which have through bores aligned with respective bores in the two units in the mated condition, and offset from the bores connected to the contact chambers so as to seal the chambers in the unmated condition. One or more actuators in one of the units are designed to extend into the other unit on mating and to engage with seal actuator tabs in both units during mating to roll the seals from the closed to the open position. The same actuators are designed to engage the seal actuator tabs in the opposite direction during de-mating, to roll the seals back into the closed, sealed condition.
One problem with subsea mateable connector units is that sand, silt or debris may infiltrate the optical fluid chamber after repeated mating and de-mating, resulting in optical issues.
Embodiments described herein provide for a tool or apparatus that allows for flushing and replenishment of fluid in a deployed, bulkhead optical or electro-optical connector unit, such as a rotating seal or rolling seal connector unit.
According to one aspect, a flush and fill apparatus for a fixed or bulkhead mounted subsea connector unit is provided. In one embodiment, the apparatus or tool comprises an outer shell with an open forward end, a front seal assembly in the forward end portion of the outer shell configured for sealing engagement with a corresponding connector seal assembly at the forward end of a mating subsea connector unit and having at least first and second seal openings configured for alignment with corresponding openings in the connector seal assembly in a mated condition of the tool and connector unit, a flush and fill assembly mounted in the outer shell behind the seal assembly and comprising a transverse wall having a plurality of passageways aligned with respective seal openings in the seal assembly at least in the mated condition of the tool, a fill reservoir and a return reservoir mounted behind the transverse wall and connected to respective first and second passageways in the transverse wall, each reservoir having a forward end and a rear end, and a fluid injection or fill pin and a fluid return pin projecting forward from the respective first and second passageways in the transverse wall and each having a through bore communicating with the respective first and second passageways. In one aspect, the fill and return pins are configured to extend through the respective first and second seal openings at least in the mated condition of the tool into sealing engagement with aligned openings in the connector seal assembly to communicate with a connector contact chamber of the mating subsea connector unit. The fill reservoir contains optical fluid in an unmated start condition of the tool, and a fill plunger is sealably and movably mounted in a rear end portion of the fill reservoir. A biasing device associated with the fill plunger is configured to push the fill plunger towards the front end of the reservoir after the tool is mated with the subsea connector unit, whereby optical fluid is ejected from the fill reservoir and injected into the contact chamber in the mated connector unit through the first passageway and fill pin through bore, and used optical fluid is flushed from the contact chamber through the return pin through bore and second passageway into the return reservoir. The fill and return reservoirs are of predetermined volume sufficient to flush all used optical fluid from the connector contact chamber into the return reservoir and replace the flushed optical fluid with new optical fluid from the fill reservoir.
In one embodiment, the subsea connector is a rolling seal connector and the seal assembly in the fixed connector unit comprises one or more rolling seals which are actuated by actuator members or rods in the connector unit which extend into aligned openings at the forward end of the tool to rotate the connector unit seal between the closed and open position on mating and from the open to the closed position as the parts are disconnected or de-mated. The seal in the tool seal assembly in this embodiment comprises at least one cylindrical seal of similar design to the rolling seal in the connector unit, and has through bores for alignment with corresponding bores in the rolling seal in the mated condition. In one embodiment, the through bores are sealed in the unmated condition and are opened by movement of the pins through the bores on mating engagement with the fixed connector unit. In one embodiment, the bores are sealed at their forward ends by a thin membrane which is pierced by the pins as the tool is mated to the bulkhead connector unit.
In one embodiment, the flush and fill tool is designed with a seal and actuator mechanism substantially matching that of a plug or flying connector unit mateable with the bulkhead mounted connector unit, but arranged to be partially mated to the bulkhead connector, so that the pins do not engage aligned optical contacts in the contact chamber when the tool is in mated engagement with the connector unit (unlike the mated condition of the plug and receptacle units). The tool is configured so that the outer ends of the fill and return pins are spaced from the optical contacts in the mated condition during flushing and filling of the contact chamber.
The injection pin or probe has an inner end in communication with the clean or unused optical fluid reservoir and the return pin or probe has an inner end in communication with the captured or return fluid reservoir, respectively. Once the tool is connected with the connector unit with the pins extending into the optical fluid-filled chamber or in communication with the chamber, a piston in the fill reservoir is actuated to force clean optical fluid out of the reservoir and through the injection or fill pin into the optical contact chamber, flushing old optical fluid from the chamber and through the return pin into the return fluid chamber or reservoir. The force for fluid injection is provided by a suitable biasing device which advances the plunger in the clean fluid reservoir to eject fluid from the reservoir and into the bulkhead mounted connector unit. The piston may be actuated by a quick release actuator either manually or via an ROV. One way valves in the fluid passageways between each reservoir and through the pins block backflow from the chamber into the fill reservoir and from the return reservoir into the contact chamber during mating and operation of the tool. Once the flushing procedure is complete, the tool is retracted away from the bulkhead connector unit, with the stationary “rolling” seal or seals biased into sealing engagement with the connector unit seals until those seals are rotated back into the closed and sealed condition.
In one embodiment, a forward end of the seal assembly in the tool is configured for face to face engagement with a forward end of a receptacle unit seal assembly, and has one or more cylindrical seals with seal openings corresponding in number to the seal openings in the mating bulkhead connector unit. The tool also has the same number of pins as the seal openings, with each pin aligned with a respective seal opening. One of the pins is the fill pin and a second pin comprises the return pin. The remaining pins are all dummy pins with no through bores designed for sealing engagement in corresponding openings in a rolling seal of the fixed connector unit. The pins are of suitable rigid material and are of shape and dimensions substantially matching those of a flying connector or plug unit designed for mating engagement with the fixed connector unit with which the tool is to be used. The pins may be shorter in length than those of the flying connector unit in some embodiments. The injection and return pins and dummy pins are designed for projecting out of the openings and through the seal member bores into the aligned receptacle unit bores when the seal members are in the open position. At least one actuator in the receptacle projects through an aligned bore in the tool when mated, the actuator rod having a formation for moving the rolling seals of the connector unit back and forth between the closed and open positions.
In one embodiment, the optical fluid fill or supply reservoir and the captured fluid reservoir which receives old fluid flushed from the receptacle contact chamber are both pressure compensated chambers. The fill reservoir contains a sufficient amount of optical fluid to fill and flush the optical chamber of the deployed connector unit.
Other features and advantages of various embodiments will become more readily apparent to those of ordinary skill in the art after reviewing the following detailed description and accompanying drawings.
The details of various embodiments of a subsea connector flush and fill tool, both as to its structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which:
Certain embodiments as disclosed herein provide for a flush and fill tool for flushing and replacing old optical fluid from one or more contact chambers in a bulkhead mounted optical or electro-optical connector unit with unused or recycled optical fluid.
After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. As such, this detailed description of various alternative embodiments should not be construed to limit the scope or breadth of the present invention.
The drawings illustrate embodiments of a flush and fill tool for flushing and replenishment of optical fluid into a deployed bulkhead optical connector unit which is designed for releasable mating engagement with a matching connector unit at the end of a cable. Although the tool is designed for mating engagement with an optical connector unit in the illustrated embodiment, the tool may also be designed for mating with an electro-optical unit in alternative embodiments. The tool may be used for replacing optical fluid in a connector designed for use in any harsh environment, not only underwater or at great ocean depths, although it is particularly intended for use in subsea applications.
The tool of the following embodiments is designed for replenishing optical fluid in bulkhead mounted rolling seal connector units for use in a harsh environment or underwater connector, for example the rolling seal optical or hybrid electro-optical connectors of Teledyne ODI, as described in U.S. Pat. No. 6,017,227 of Cairns or US Pat. App. Pub. No. US 2015-0036986 of Kretschmar et al., the contents of both of which are incorporated herein by reference. Rolling seal connectors have a fixed, bulkhead mounted receptacle unit and a flying connector or plug unit at the end of a subsea cable which is releasably mateable with the receptacle or bulkhead unit. In the unmated condition, a contact chamber in the receptacle unit is sealed at its forward end by one or more rolling seals which have through bores aligned with respective optical contacts in the mated condition, and offset from the optical contacts and contact chamber openings so as to seal the chambers in the unmated condition. One or more actuators in the bulkhead connector unit are designed to extend into the flying or plug unit on mating and to engage with seal actuator tabs in both units during mating while the receptacle seal manifold carrying the seals is urged inward into the receptacle shell, so that the seals are rolled from the closed to the open position. The same actuators are designed to engage the seal actuator tabs in the opposite direction during de-mating, to roll the seals back into the closed, sealed condition. When the plug unit engages the forward end of the receptacle unit, the rolling seals in both units are rotated into the open position so that contacts in the plug unit can project through the aligned openings and contact the aligned contacts in the receptacle unit. As noted above, one problem with such connectors is that they have a limited mate count as a result of sand, silt or debris which tends to enter the optical manifold of the bulkhead unit after repeated mating and demating, resulting in poor optical performance. This typically requires recovery of the bulkhead unit for maintenance or replacement.
A flush and fill assembly 11 is mounted in the shell behind the seal assembly 20, and basically comprises transverse wall or mounting block 24 having first and second passageways 44, 45 aligned with respective seal openings in the seal assembly at least in the mated condition of the tool, a fill reservoir 36 and a return or captured fluid reservoir 38 mounted behind the transverse wall and in communication with the respective first and second passageways in the transverse wall, a fluid injection or fill pin 28 and a fluid return pin 30 projecting forward from the respective first and second passageways in the transverse wall, and solid dummy pins 29 also projecting forward from wall 24. Each pin 28, 30 has a forward end and a rear end and a through bore or passageway 35 between the forward and rear ends communicating with the respective first and second passageways 44, 45. In an alternative embodiment, fill and return pins 28, 30 may project through wall 24 and communicate directly with reservoirs 36 and 38, respectively.
In the illustrated embodiment, the forward ends of the seal bores 31, 32 and 34 are sealed by a thin membrane 33. Fill pin 28 and return pin 30 are aligned with first and second bores 31 and 32, respectively. The other pins 29 are solid, dummy pins and are aligned with the other two bores 34. The total number of pins per seal depends on the number of contacts associated with each rolling seal of the fixed connector unit with which the tool is intended to be used. In the illustrated embodiment, four pins are associated with each seal but a different number of pins and corresponding seal bores may be provided in other embodiments. There are two rolling seals 25 in the illustrated embodiment, and each seal is associated with a separate set of four pins, with only one set of pins and one seal visible in
In the illustrated embodiment, the two dummy pins 29 also project outwardly from transverse wall 24 toward the seal 25, in alignment with respective seal bores 34. A greater number of dummy pins may be provided in other embodiments, depending on the number of seal bores which in turn depends on the number of openings or bores in an opposing seal member of the mating connector unit. Additionally, the illustrated embodiment has two front seals in front end wall 21 which each have four seal openings, but there may be one or three or more seals in alternative embodiments, depending on the number of rolling seals in the connector unit with which the tool is to be mated. In the illustrated embodiment, four additional dummy pins (not visible in the drawings) extend from transverse wall 24 in alignment with openings in the second seal 25, and the injection and return pin are both aligned with openings in the first seal 25. In alternative embodiments return pin 30 may be replaced with a dummy pin, and the return pin with through bore 35 may instead be positioned in alignment with one of the openings in the second seal 25, with the second passageway 45 and return reservoir aligned with the return pin associated with the second seal. In this alternative, each seal has three openings or bores aligned with respective dummy pins, and one opening or bore aligned with the respective injection or return pin. In one embodiment, the pins are of substantially matching shape and dimensions to the pins of a flying connector or plug unit designed to mate with the bulkhead connector unit during normal operation of the subsea connector.
A greater or lesser number of rolling seals and associated sets of pins may be provided in other embodiments, depending of the number of rolling seals in the fixed or bulkhead unit with which the tool is to be mated and the number of openings in each seal, which in turn depends on the number of connections to be made between the bulkhead and mating connector unit, such as four, six, seven, eight, nine, ten or twelve or more.
As best illustrated in
The actuator latching spring 57 secured within a frusto-conical shaped indent at the rear end of piston 50 engages the head of actuator pin 55 and holds the actuator pin and piston in place in the retracted position. When the actuator pin 55 is moved out of the indent and away from the latching spring, the biasing force of the piston spring 54 moves the piston 50 forward, urging plunger 48 forwards to eject fluid from the reservoir 36, as described in more detail below in connection with
The first stepped through bore 44 in mounting block 24 is aligned with the through bore 35 in fluid injection or fill pin 28 at one end and with the fill reservoir outlet passageway 40 at the opposite end. The second stepped through bore 45 is similarly aligned with through bore 35 in fluid return pin 30 at one end and the inlet passageway 42 of the fluid reservoir or return chamber 38 at the opposite end. A one way valve 58 seals the outlet passageway 40 of clean fluid reservoir 36 while one way valve 60 seals the inlet or return passageway 42 to captured fluid reservoir 38 both in the unmated condition of
The flush and fill tool 10 of
A pair of actuator rods 84 fixed in the base or end wall of the shell extend slidably through respective passageways 85 in manifold block 74, and a third actuator rod 86 is fixed at one end in the end wall and extends slidably through passageway 88 between the rolling seals 72. The ends of the actuator rods are seen in
The front end manifold or wall 21 of the flush and fill tool is provided with corresponding passageways 90 and 92 for alignment with actuator rods 84 and 86 in the bulkhead unit during mating of tool 10 and connector unit 12. One or more alignment keys or tabs 94 (
The receptacle rolling seals have rigid axles while the remainder of the seal is of elastomeric material. In the illustrated embodiment, the tool seals are fixed and may be completely elastomeric or may have rigid cores. As noted above, prior to connection of the tool and receptacle units in this embodiment, each of the elastomeric seals 25 and 72 projects partially outwardly from the respective tool and receptacle manifold end face, as best illustrated in
Once the tool 10 is properly mated with the bulkhead connector unit 12 as in
The one way valve 58 prevents backflow from optical chamber 82 into clean fluid reservoir 36 during mating of the tool with the bulkhead connector unit 12. The backflow direction of one way valve 60 is reversed from that of valve 58, so that used optical fluid cannot flow back from capture reservoir or chamber 38 into optical chamber 82 during flushing or during de-mating when the flush or fill procedure is complete.
The reservoir 36 contains at least the same amount of optical fluid as the contact chamber in the bulkhead connector unit 12, and may contain more optical fluid than chamber 82 to ensure sufficient flushing of chamber 82, and return fluid reservoir 38 has the same capacity as reservoir 36, so that all or substantially all old or dirty optical fluid is flushed from the chamber 82 into return reservoir 38 when the plunger 48 is in the advanced position illustrated in
Once the contact chamber has been completely flushed and re-filled with new or recycled optical fluid, the tool 10 is separated from the connector unit the same way as a mating flying connector unit or plug unit at the end of a cable would be separated from the bulkhead unit. As the units are de-mated, the movements described above are reversed as the return spring in the bulkhead unit pushes the receptacle manifold 74 outward relative to the seal actuator rods, with actuator rod 86 (
The subsea connector flush and fill tool described above has two cylindrical seals each having four through bores and associated sets of four pins for extending through the seals of the tool and the mating connector unit to allow flushing of old optical fluid and filling with new optical fluid. However, a similar tool may be provided in alternative embodiments with a greater or lesser number of cylindrical seals for use with bulkhead connectors with one, three or more rolling seals, or with cylindrical seals having a different number of through bores. The tool 10 has a corresponding number of pins for mating with bulkhead connector seals which have the same number of through bores or passageways through the seal. The tool may be configured for mating with rolling seal bulkhead connector units having 6, 7, 8, 9 or 12 way configurations, and may be customized for any specific contact and seal arrangement, as well as for flushing optical chambers of hybrid electro-optical connectors. Additionally, the above embodiment has cylindrical seals or seal members designed for sealing engagement with corresponding cylindrical rolling seals of the mating bulkhead connector unit, but flush and fill tools of alternative embodiments may have seals of different shape and design matching those of different types of bulkhead connector units, such as connector units with rotating seal members of disc-shape which rotate about the central longitudinal axis of the connector unit, rather than transverse to that axis as is the case with rolling seal connectors. It will be understood that rollable shapes other than cylindrical may be used for the mating seals and recesses, such as spherical or part-spherical, and the tool is designed with appropriate rolling or other shaped seals matching those of the bulkhead mounted connector unit with which it is sealably engaged during flushing and filling of the optical contact chamber or chambers.
The subsea connector flush and fill tool described above allows for flushing of old optical fluid and replenishment of unused or recycled optical fluid into a deployed bulkhead optical or hybrid electro-optical connectors, without the need to remove subsea deployed hardware for maintenance at a remote ship or land location. The tool allows for correction of optical issues resulting from sand, silt or debris infiltration into the optical manifold of a bulkhead connector unit, as well as exceeding the recommended mate/demate count for the connector. The tool also provides the means to retain the old optical fluid from a deployed connector and recover it for analysis.
The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art and that the scope of the present invention is accordingly limited by nothing other than the appended claims.