Magnetically Attracted Connector System and Method

BACKGROUND

Technical Field

This application is related to quick disconnect connectors, and more particularly, to quick disconnect fluid-dispensing and fuel-dispensing connectors.

Related Technology

For Naval vessels, refueling at sea can be challenging, dangerous, and sometimes deadly. Refueling unmanned surface vessels (USVs) and unmanned underwater vessels (UUVs) can be even more difficult, because sailors are often hoisted overboard by crane to manually refuel the vehicles. This maneuver is particularly dangerous in high sea states.

BRIEF SUMMARY

One aspect of an invention is directed to a magnetic connection system having at least three components for connecting a host system and a target system, comprising: a first connector configured to be attached to the host system and having a ring magnet; a second magnetic target connector configured to be attached to the target system and having a ring magnet; and a third magnetic connector configured to be positioned between the first connector and the second connector and having a ring magnet, the ring magnets being approximately equal in diameter such that the first connector, second connector, and third connectors fit together with the ring magnets aligned.

The ring magnet in the third connector can be positioned in the interior of the connector, closer to one face of the connector than to an opposite face of the second connector. In operation, the face of the third connector that is further from the third connector's ring magnet faces toward the first connector, and the face of the third connector that is further from the third connector's ring magnet faces toward the second connector, such that the third connector has a stronger attraction to the second connector. The first connector's ring magnet can be located at a face of the first connector that faces the third connector, and the second connector's ring magnet can be located at a face of the second connector's ring magnet that faces the third connector. The third connector includes a conduit passing from an outer circumferential edge of the third connector to a central location on the one face of the third that is closer to the interior ring magnet. The conduit can be a fluid flow conduit.

The second connector can have a conduit passing from one face of the second connector to the opposite face of the second connector aligned with the conduit in the third connector along a common centerline of the first, second, and third connectors. The conduits can be configured to transfer electrical power or data.

The ring magnets can be permanent magnets or electromagnets.

The first connector is attached to a robotic arm, and can be attached to a robotic arm on a fuel supply vessel, with the second connector being attached to a vessel to be refueled. The third connector can have a fuel conduit passing from an outer circumferential edge of the second connector to a central location on the one face of the connector that is closer to the interior ring magnet. The system can also include a flexible fuel line extending between the fuel supply vessel and the third connector, and a tether attached to the third connector having a shorter length than the flexible fuel line.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example of a refueling system that includes a three-component magnetic connector system.

FIG. 2 A, 2B, and 2C illustrate an example of a three-component magnetic connector system configured with one of the connectors on the end of a robotic arm.

FIG. 3A and 3B show the three magnetic connector components without the robotic arm, fuel line, and target vessel from two different viewpoints.

FIG. 4 is a cross sectional view of a connector system with the three primary magnetic connectors.

FIG. 5 is a cross sectional view of another example connector system. FIG. 6A and 6B illustrate schematic drawings of an example magnetic system casing 180 for a connector.

FIG. 7 A, 7B, and 7C are schematic drawings of an example puck connector, showing a fluid conduit.

DETAILED DESCRIPTION OF THE INVENTION

The examples shown herein are provided to demonstrate a quick-disconnect robotic fuel dispensing connector that attaches the host system to a target system and transfers fluid between the two of them, allowing fluid transfer in conditions where the host and target systems are moving independent of each other at unknown and uncontrolled relative rates, and to reduce or eliminate the need for human intervention in the process.

The connector is also known as an "end effector", and is capable of self- alignment and autonomous connection to the target fuel tank without direct human intervention.

An example of a refueling system that includes the connector system 100 is shown in FIG. 1. In this example, a first connector component 110 is attached to or part of a robotic arm 30 that extends from the refueling vessel 10 toward the target vessel 20 (the vessel to be refueled). A second connector component 170 is attached to or part of the host vessel 20 that is to be refueled by the robotic refueling arm 30. A third connector component or "puck" 150 has the fuel conduit and is generally arranged between the first and second connector components.

In this example, each of the first connector component, the second connector component, and the third connector component are formed of a non-magnetic material, and include a magnet, as will be discussed in more detail. Suitable materials for the non-magnetic material include metals such as aluminum.

The magnets can be permanent magnets or electromagnets. The magnets can be formed of ferromagnetic materials, which are materials that can be magnetized and which are those that are strongly attracted to a magnet. These materials include iron, nickel, cobalt, some alloys of rare earth metals, and some naturally occurring minerals such as lodestone.

Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically "hard" materials, which do. Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferrite that are subjected to special processing in a powerful magnetic field during manufacture, to align their internal microcrystalline structure, making them very hard to demagnetize. An electromagnet is typically made from a coil of wire that acts as a magnet when an electric passes through it but stops being a magnet when the current stops. To enhance the magnetic field produced by the coil, the coil can be wrapped around a core "soft" ferromagnetic material such as steel. The overall strength of a magnet is measured by its magnetic moment or, alternatively, the total magnetic flux it produces. The local strength of magnetism in a material is measured by its magnetization. As seen in FIG. 2A, when the robotic arm is far away from the target vessel 20, the first component 110 and the puck 170 are held together by magnetic attraction between them.

When the robotic arm is moved close to the target vessel, the magnetic attraction between the puck 170 and the second component 150 helps align the puck and first connector on the end of the robotic arm with the second component on the target vessel. FIG. 2B shows the first connector, second connector, and third connector held together by magnetic attraction.

As shown in FIG. 2C, if the robotic arm and target vessel 20 move away from each other with a sudden jolt, because the magnetic field strength between the first connector 110 and the puck 150 is weaker than between the puck 150 and the second connector 170, the first connector 110 and its robotic arm are pulled away from the puck. However, the stronger magnetic attraction between the puck 150 and the second connector 170 on the target vessel keeps the puck seated against the second connector, allowing the fuel to continue to flow into the target vessel's fuel tank.

FIG. 3A and 3B show the three components without the robotic arm, fuel line, and target vessel from two different viewpoints. FIG. 4 is a cross sectional view of the three components.

The first connector 110 has a body 115 formed of a nonmagnetic material such as aluminum, with a circular groove 114 in the mating face 113 of the connector. A ring magnet 112 is affixed within the circular groove. In this example, the surface of the ring magnet 112 and the connector face 113 are flush, allowing the entire face of the connector 110 to mate with the surfacel54 of the puck 150.

The second connector 170 has a body 175 formed of a nonmagnetic material such as aluminum, with a circular groove 174 in the mating face 113 of the connector. A ring magnet 172 is affixed within the circular groove. In this example, the surface of the ring magnet 172 and the connector face 173 are flush, allowing the entire face 173 of the connector 170 to mate with the surface 153 of the puck 150.

The puck 150 can also include a conduit 156 through which a fuel or other liquid will flow into a matching conduit 176 in the second connector 170. The fluid flow conduits are preferably positioned along the centerline of the system, so that fluid conduits will line up regardless of any rotation of any of the three components around the central axis.

The puck 150 has a ring magnet 152 that is embedded within the non-magnetic body 155 of the puck. The ring magnet is preferably located closer to one face of the puck than to the other face of the puck, so the magnetic attraction between the puck and one of the connectors will be stronger than between the puck and the other one of the connectors. In this example, the ring magnet is located closer to surface 153 that, in operation, faces the target vessel connector 170. In this way, if the movement between the two vessels is great enough to pull the connectors apart while fuel is being dispensed, the fuel-dispensing puck 150 will be more attracted to the fuel-receiving target vehicle connector 170 than to the first connector 110 on the host vehicle's robotic arm.

For example, the ring magnet 152 could be 1/2 inches from the puck surface 154 and 1/4 inches from the opposite puck surface 153. If a change in magnetic strength is necessary for a particular application, the puck 150 can be thinned on one side by machining away some of the puck on one of the faces until the desired relative magnetic field strengths are obtained. Although the ring magnets in the first and second connectors are shown as flush with the connector surfaces in FIG. 4, it can also be suitable for the ring magnets 112 and 172 in the connectors to be set back from the surfaces of the connectors 110 and 172. They can be set back from the near surfaces by the same amount, so that the magnetic field strength between each pair of magnets being set by the location of the ring magnet 152 in the puck 150. It can also be suitable for the faces of the components to have matching mating surfaces that are not flat. For example, the second connector 170 can have a concave surface, with a matching convex face on the surface 153 of the puck. This can improve initial alignment between the connectors and reduce or prevent spillage.

Referring again to FIG. 4, it is seen that the ring magnets are circular and have a same diameter. This provides a self alignment capability, with magnetic attraction between the ring magnets 112 and 152 and between the ring magnets 112 and 172, the such that the magnetic fields will cause the connectors to move together with the ring magnets vertically aligned. This provides a self alignment capability for the system.

Because the ring magnets are circular and the fuel conduits 156 and 176 through the puck and the second connector are arranged along the centerline of the system, the puck 150 can rotate in any direction, as long as it is sandwiched between the connectors 110 and 170, and the fuel will continue to flow through the puck into the target vessel.

Note that the first connector 110 does not include any part of the flow conduit, so if it is pulled away from the target vessel connector 170 and puck 150, connection between the fuel line and the target vessel will not be lost.

In a currently preferred example, the bodies of each of the connectors 110, 150, 170 are a non-magnetic metal such as aluminum and the ring magnets 112, 152, 172 are rare earth element magnets.

The system can include an electronic-disconnect sensor (not shown) to determine when either portion of the system has lost connection. Thus, when the puck 150 loses connection with either the first connector 110 or the second connector, the disconnect sensor and an associated control system can cause a shut-off of the flow through the conduit, sound an alarm, or take other actions. The system can also incorporate a wired or wireless

communications link to inform the system operator of loss of the connection.

The system can also include flexible rings (not shown) on the mating surfaces that improve the seal between the puck 150 and the target vessel connector 170 and/or the host vessel connector 110. As shown in FIG. 5, the system can also include one or more protrusions 157 on the target-side of the puck face 153 that open a flow valve 177 within the target fuel receptable when attached, to prevent backflow.

FIG. 6A and 6B illustrate schematic drawings of an example magnetic system casing for a connector. The groove houses the ring magnet for the connector.

FIG. 7 A, 7B, and 7C are schematic drawings of an example puck connector, showing a fluid conduit. The interior ring magnet is not shown.

Referring again to 1, FIG. 2A, 2B, and 2C, fuel line 50 is a flexible hose that is not structurally supporting, and has sufficient slack in its length that it is unaffected by dramatically shifting distances between the host system and the target system.

However, the system can also include a tether 60 attached to the puck 150 at one end and to a component of the robotic arm or the host vessel at the other end. The tether 60 and the fuel transfer line 50 are both sufficiently long to allow the puck 150 to remain in contact with the target vessel connector 170 in spite of some motion between the host vessel and the target vessel. The tether 60 but will pull the puck away 150 from the target vessel connector 170 if the separation becomes too great. In a preferred embodiment, the tether 60 is slightly shorter than the fuel supply line 50 so any strain will be taken up by the tether rather than the fuel line. This prevents damage to the fuel line 50 and loss of the puck 150.

In systems in which one or more of the ring magnets are electromagnets, rather than permanent magnets, the system will also include a control system that energizes or deenergizes each of the electromagnets. The inclusion of electromagnets provides active control of the connection between the host and the puck, as well as between the target and the puck. This active control allows the magnetic field between the puck and target system to be deactivated, so the puck can be captured by the host connector and stowed on the host vessel with the other refueling system components. Without electromagnets, the puck is manually removed from the target vessel connector, or pulled away by the tether.

The examples discussed above refer to a fuel or fluid transfer system. The system can additionally include connectors for electrical power, data, or other transferrable entities. The system can also be configured to transfer only power or data, with no liquid transfer, and with the conduit through the puck 150 and the second connector being suitable for carrying the data or power (e.g., data transfer lines, optical fibers, communications lines, electrical conductors, etc.). The system can also include rubber or other flexible rings or gaskets between the mating surfaces to improve the seal between the surfaces.

The system described herein can also suitably be used for non-fluid applications. For example, the system can connect the host and target systems and transfer power, data, or a combination of power, data, and fluid. The system is not limited to ships or other waterborne vessels. In other examples, the host and target systems between which an entity is transferred are unmanned or manned systems, underwater vehicles or systems, ground vehicles or systems, aircraft, robotic systems, or space or satellite systems.

The invention has been described with reference to certain preferred embodiments. It will be understood, however, that the invention is not limited to the preferred embodiments discussed above, and that modification and variations are possible within the scope of the appended claims.