1) Field of the Invention
The present invention is directed to vehicle recovery systems. Specifically, the present invention relates to a vehicle recovery system having a rotary capture device compatible with a passive engagement and an active release device of a vehicle to be recovered.
2) Description of Prior Art
Unmanned Surface Vehicles (USV) provide an expanding range of applications. However, USVs face a challenge when deployed from and recovered by larger vehicles such as ships—especially when the vessels are operating in varying sea states. Therefore, a reliable, robust and simple system for transitioning between self-propelled and captured states is necessary for mission effectiveness.
Mayo (U.S. Pat. No. 3,653,101) recites a quick-release, self-locking hook attached to a buoy which is connected to an embedded anchor by a heavy chain or wire rope. The cited reference is directed to a self-locking capability to attempt to eliminate the necessity of human intervention in the locking process. The reference recites that this is accomplished by providing a locking keeper that is pivotable for full rotation.
Epstein (U.S. Pat. No. 3,762,757), recites that in the mooring of ships and boats to a dock, it is necessary to have a line run from the ship or boat to the dock. The line can be more or less tight and must be fixed so as to allow relatively little movement of the ship or boat with respect to the dock. When it is necessary to allow the ship or boat to move away from the dock, it is also necessary to disengage the line from the fastening means on the dock. This reference relates to a fastening means whereby a line can be positioned to the fastening means for securing the ship or boat adjacent to the dock. Then, the person on the dock can mechanically actuate the fastening means to allow the line to slip away from the fastening means and also to allow the ship or boat to sail away from the dock. This fastening means is identified as a releasable hook. When it is desired to have a ship or boat fixedly secured with respect to the dock; the fastening means is in a locked position to firmly position the line. When it is desired to allow the line to be slipped and to allow the ship or boat to sail away from the dock; the operator on the dock can disengage the fastening means, or releasable hook from the line.
Schulz (U.S. Pat. No. 3,868,922), discloses an automatic latch/unlatch mechanism comprising a housing having a plurality of latches pivotally attached thereto. A probe inserted into the housing at a specific first distance and moved in the opposite direction at a specific second distance, is engaged by the latches and prevented from being extracted from the housing. Then, if the probe is moved at a specific third distance into the housing; the probe may be extracted therefrom.
McClain (U.S. Pat. No. 3,918,386), recites a boat docking device mounted on the bow of a boat with the device comprising a housing member having forward surfaces slanting inwardly to a slot for receiving a mooring line, a latch pivotally mounted in the housing member between a locked and unlocked position, and a retractable biased pin urged against the locking member for securing the latch in a locked position.
Ortloff (U.S. Pat. No. 4,677,930) recites an apparatus for securing two offshore mooring sections together. The apparatus is a connector adapted to disengage each mooring section so that an offshore floating storage vessel (having one mooring section attached) may be separated from the riser of a single anchor leg mooring system—having the other mooring section attached. The connector comprises a pin member engageable with a hook of a latch member. The latch member is rotated once the hook engages the pin member and a plunger then advances into an open region of the hook; thereby, prohibiting the rotational movement of the latch member and locking the two mooring sections together.
In Held et al. (U.S. Pat. No. 5,082,318), a girth hitch is secured about an object by a girth hitching mechanism having a rotatable actuator gate which displaces a latch gate that has a parrot hook that loosely supports a portion of a closed girth loop. A latch ring joined to the girth loop by a latch ring bite is engaged by the parrot hook when the latch gate and actuator gate are rotatably displaced as the object enters the throat of a fork which supports the latch gate, actuator gate and latch ring. After the parrot hook engages the latch ring and the latch gate is rotated in the opposite direction by the object to disengage the latch ring, the girth loop is pulled from its loose support on the parrot hook into a girth hitch configuration about the object to enable recovery via an attached lift line.
In McMillan (U.S. Pat. No. 5,123,374), a releasable toggle locking mooring hook is provided having a releasable hook, toggle linkage, a stop release mechanism, a self-locking safety latch and a self release mechanism adapted to provide a locking mooring hook and a releasing means while a mooring hook is under a tensile load. In the mooring of ships, boats and barges to a dock or oil well platform, a line, usually under tension, is run from the ship to a mooring means mounted on the dock or platform. When it is desired that the ship leave this mooring, this mooring means can be actuated manually, mechanically or by a pre-set tensioned self releasing means to release mooring line and thus, allow the ship to sail. This mooring means is identified as a releasable toggle locking mooring hook.
Exemplary embodiments of a system and method of use in accordance with the present invention are directed to a surface vehicle capture device compatible with a passive engagement and an active release device of a vehicle to be towed. In one embodiment, the capture device utilizes a recovery tow line secured to a U-shaped body or fork that is coupled to a buoyant rotor. The buoyant member is shaft-mounted in a cavity defined by two arms of the U-shaped body to which the shaft is fixedly or rotatably attached. Capture loops are pinned on ends of an outer surface of the buoyant member.
As the capture device is dragged thru the water; the buoyant member provides flotation. The capture loops provide asymmetric drag; thereby, rotating the buoyant member and capture loops around the shaft. As a vehicle approaches to latch with the capture device; a primary latch and a stem guard of a spring-loaded secondary latch (on the vehicle to be recovered) guide at least one of the capture loops into the primary latch. The secondary latch is displaced as the capture loop enters and then spring loads to a locking position that “captures” the capture loop. This capture mechanically brings the vehicle into a controlled tow.
To release the capture loop, the primary latch is freed by an actuator that releases a mechanical stop. This action allows the primary latch to rotate about a pin. Once released, the system resets for capture by reversing the action of the actuator and torsional springs.
An advantage of the present recovery system is that passive latching is achieved by simply positioning the craft bow in proximity to the capture device. No active reset of the device is needed when a miss occurs in the docking procedure. Active system control is only used to release the recovered vehicle from the capture device.
The material of the capture loops can be synthetic line, wire rope or formed solid rods. Paddle size can be varied to control rotational velocity and wake signature; preferably with the least amount of drag and the most stable over the broadest range of recovery speeds. Also, positioning of the paddles on the drum can be used to control rotational velocity and wake signature. The capture device can be towed alone or coupled to other recovery equipment.
An integral passive pump can be used to enhance a recovery effect. Some types of personal water craft have a diversion outlet that sends a portion of the propulsion water jet into the air (allowing an increase the visibility of the watercraft). In the present invention, two streams of water from the vessel with the capture loops; form fluid guide posts for a visual recovery of the vessel to be towed.
It will be understood that many additional changes in details, materials, steps, and arrangements of parts which have been described herein and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims:
In the description which follows, any reference to either direction or orientation is intended primarily and solely for purposes of illustration and is not intended in any way as a limitation on the scope of the present invention. The particular embodiments described herein, although being preferred, are not to be considered as limiting the present invention.
Referring initially to
The system 100 comprises a capture device 104 and a spring-loaded towing latch 106. The capture device 104 is a U-shaped body 108 arranged with opposing arms 110 that are spaced from each other to define an open-ended cavity 112. A shaft 114 is attached to each one of the two arms 110 and extends through the cavity 112. The shaft 114 can be fixedly attached or rotatably attached to each arm 110.
The capture device 104 includes a tow line 116 attached to the U-shaped body 108 opposite the cavity 112. The tow line 116 attaches at another end to the towing vessel. The tow line 116 is deployable and retractable from the towing vessel—for example, from a spooling mechanism attached to the towing vessel. Suitable tow lines are known in the art.
The capture device 104 includes a buoyant member 118 rotatably disposed in the cavity 112. In one embodiment, the shaft 114 is fixed and the buoyant member 118 rotates around the fixed shaft. Alternatively, the buoyant member 118 is fixedly attached to the shaft 114, and the shaft rotates.
The capture device 104 includes a plurality of capture loops 120 disposed to fit and easily move within the cavity 112. Each of the capture loops 120 are attached to the buoyant member 118 and the shaft 114 and are rotatable with the buoyant member. Each capture loop 120 and the buoyant member 118 define a closed loop. These closed loops are capable of engaging the spring-loaded latch 106 that is attached to the vehicle 300.
The buoyant member 118 is a cylindrical drum having an outer surface 123 and two ends (a first end 124 and a second end 126). The first and second ends 124, 126 are circular and preferably are formed as semi-spherical caps. The cylindrical drum and the ends 124, 126 can be formed as a sealed unit to create buoyancy or can be constructed of or covered by a buoyant material.
A central axis 128 passes through the cylindrical drum between the ends 124, 126. The shaft 114 extends through the ends 124, 126 along the central axis 128. In one embodiment, each capture loop 120 is formed from a curved rod attached to the outer surface 123 of the cylindrical drum at two locations.
A first location is disposed adjacent to the first end 124 of the cylindrical drum and a second location is disposed adjacent the second end 126 of the cylindrical drum. Each curved rod extends along the outer surface 123 of the cylindrical drum along a line parallel to the central axis 128 and extends radially outward from outer surface of the cylindrical drum to form an arched shape defining the closed loop.
In one embodiment, the capture loops 120 also provide for rotation of the buoyant member 118 and the attached capture loops within the U-shaped body 108. As the capture device 104 is pulled along the water surface by the tow line 116 in the direction of travel “A” of the recovery vessel and the captured vehicle 300; a corresponding rotational motion is induced in the buoyant member 118 and the capture loops 120. As illustrated, each capture loop 120 is moved vertically out of the water surface. This rotational motion facilitates engagement in the downwardly-facing and spring-loaded towing latch 106.
In one embodiment, the buoyant member 118 and the capture loops are sized and shaped to rotate about the shaft 114 at a predefined rotation speed. The rotational speed of the buoyant member 118 is preferably thirty rotations per minute. The diameter of the buoyant member 118 is the perimeter of the buoyant member. The speed of a towing action provides a distance over time while the perimeters give revolutions over time as a RPM (revolutions per minute).
Suitable materials for the U-shaped body 108, the shaft 114, and the buoyant member 118 include, but are not limited to a buoyant material, aluminum, titanium, carbon fiber, a polymer and combinations thereof. Suitable materials for the capture loop 120 include, but are not limited to, a synthetic line, a wire rope and a formed solid metal rod.
Referring to
Each paddle 210 is a solid plate extending radially outward from the outer surface of the cylindrical drum and along the outer surface of the drum between the two ends parallel to the central axis. In one embodiment, each paddle 210 has a central portion 212 attached to the buoyant member 202 and two parallel plates extending outwardly from the central portion on two parallel planes. A first plate 216 extends outwardly from the central portion at a first distance and a second plate 214 extends outwardly from the central portion a second distance. The first distance is greater than the second distance.
The cylindrical drum includes a plurality of distinct wedge-shaped segments 208 that are fitted together to define the outer surface of the buoyant member 202. In one embodiment, the wedge-shaped segments 208 are fitted over a cylindrical central portion 218 of the buoyant member 202. These wedge-shaped segments 208 can be formed from a buoyant material with the paddles 210 attached to the wedge-shaped segments.
As illustrated, the buoyant member 202 is fixedly attached to the shaft 206, and the shaft is configured to rotatably engage with the two arms 110 of the U-shaped body 108. Each capture loop 204 is also fixedly attached to the shaft 206. Therefore, rotation of the shaft 206 rotates the buoyant member 202 and the capture loops 204. The paddles 210 induce rotation of the buoyant member 210. The use of paddles allows the use of fewer capture loops 204, thinner or larger capture loops or capture loops formed of a flexible material such as wire rope as the capture loops are not used to induce rotation of the buoyant member 202.
Returning to
In general, the towing latch 106 includes a moveable hook having a first open position and a second closed position. The hook is moveable from the first position to the second position under action of a biasing spring upon engagement of one of the capture loops over the hook. As illustrated in
The towing latch 106 also includes a secondary latch 142 attached to the primary latch 136. The secondary latch 142 is biased in a locked position away from the hook by a biasing spring. The secondary latch 142 moves toward the hook to allow passage of one of the capture loops 120 for engagement of the hook and securing of the capture loop in the towing latch 106. When the secondary latch 142 returns to an original biased position; the capture loop 120 is secured in the hook.
Other types and arrangements of spring-loaded towing latches can be used. In general, the towing latch 106 is biased open and closes upon engagement of a capture loop 120. As illustrated in
Recovery methods will rely on operator visual detection. Sensors and lasers can provide a spatial reference that can assist or even replace visual detection during. The capture device 104 has the advantage of being able to produce a highly visible wake to aid the operator in aiming for the final docking maneuver. Furthermore, the capture device 104 can be towed alone or coupled to other recovery equipment.
While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives of the present invention, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Additionally, feature(s) and/or element(s) from any embodiment may be used singly or in combination with other embodiment(s). Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.
The invention described herein may be manufactured and used by or for the Government of the United States of America for Governmental purposes without the payment of any royalties thereon or therefore.
Number | Name | Date | Kind |
---|---|---|---|
3653101 | Mayo | Apr 1972 | A |
3762757 | Epstein | Oct 1973 | A |
3868922 | Schulz | Mar 1975 | A |
3918386 | McClain | Nov 1975 | A |
4677930 | Ortloff | Jul 1987 | A |
5082318 | Held et al. | Jan 1992 | A |
5123374 | McMillan | Jun 1992 | A |
7798085 | Burnette | Sep 2010 | B2 |
8746766 | Lewkoski | Jun 2014 | B2 |