The present invention pertains generally to winches. More particularly, the present invention pertains to shipboard winches for deployment or recovery of cables from a body of water without damaging the cable or sensors.
Sometimes it is desired to deploy sensor arrays on the floor of an ocean or similar body of water. These arrays will often have structure wherein a plurality of sensors is fastened to a cable. To deploy the array, the cable is paid out from the fantail of a ship traveling at bare steerageway.
For arrays of this structure, it can be very difficult to deploy and recover the array without damaging some of the sensors, and deployment of the array via a mechanical means can prove to be challenging. This is because of the tension of the cable varies due to the pitch and roll of the ship and because of the allowable bend radius of the cable at the connection points with the sensors. If the tension is too great, the cable may part. In some cases, array deployment is achieved either by tensioning the cable by hand or by not at tensioning at all. Recovery can be achieved either by hand or with the assistance of friction provided by the groove space between two tires in tandem, which are powered by a hydraulic motor. In the latter case, the cable rides over the rotating groove and tension is maintained by hand on the inboard side of the tandem of tires.
Deployment and recovery of long sections of cable by hand is extremely exhausting. The friction afforded by the tandem tire groove is often inadequate as cable that has been in the sea for some time often has gelatinous marine growth on it that causes the cable to be very slippery. Also, the tension can also often become excessive if the cable gets wedged between the tires and begins to wrap around; excessive tension risks parting of the cable or damage to the sensors as the array is being deployed or recovered. Alternatively, rollers could be used as a mechanical means for deployment or retrieval of an array. But rollers produce the equivalent of a speed bump when a sensor passes therethrough, which is also potentially very damaging to both the sensor and to the cable due to the limitations of allowable bend radius at the location where the cable connect to the sensor.
In view of the above, it is an object of the present invention to provide a shipboard winch having guide vanes for maintaining adequate spacing between multiple wraps of cable with sensors. Another object of the present invention is to provide a shipboard winch having guide vanes wherein the array cable is wrapped around two rotating drums in figure eight fashion to prevent twisting of the cable and thus prevent “hockles” while applying a controlled tension on the array of sensors for deployment of the array from the deck of a ship without damaging the array. It is yet another object of the present invention to provide a shipboard winch having guide vanes that allows for recovery of the array without damage to the array sensors. Another object of the present invention is to provide a shipboard winch that deploys and recovers cables in a manner that places a constant tension on the cable during recovery, even if the cable has become fouled with marine growth. Still another object of the present invention is to provide a winch for deploying/recovering a cable from ocean without causing twists or hockles in the array cable.
A shipboard winch having guide vanes according to several embodiments of the present invention can include a first drum and a second drum that are mounted on a frame. The first and second drums can be driven by a motor so that the drums contra-rotate when the winch is activated. A plurality of guide vanes can be positioned between the first drum and the second drum. Each guide vane can be formed with a base and a distal lip that extends outwardly from the guide vane. The guide vanes are further formed with a decreasing taper when the guide vane is viewed in top plan, from a maximum width at the vane base to a minimum width at the vane distal lip. The vanes are further formed with a curved leading edge that conforms to the shape of the drum. In some embodiments, the guide vanes can be stacked on top of each other and arranged so the leading edges of immediately adjacent guide vanes extend in opposite directions to alternately conform to the curvature the first drum engagement surface and the curvature of the second drum engagement surface.
In several embodiments, the first drum and the second drum of the winch can be formed with a smooth engagement surface to prevent damage to the sensor array cable as it is deployed and/or recovered. The winch can further include a hydraulic feedback circuit that is connected to the respective motors of both the first drum and the second drum. In response to the feedback circuit, the motors can be selectively operated to vary the rotational torque of the first drum and/or second drum to maintain a constant tension on a cable as it is deployed or retrieved.
The methods for deploying/retrieving cable from the fantail of a ship according to several embodiments can include the steps of attaching a frame to the fantail and mounting two drums to the frame. The methods can further include the steps of positioning a plurality of guide vanes between the first drum and the second drum, and threading the cable around the first drum, through the guide vanes and around the second drum in a figure eight configuration. The methods can further include the steps of contra-rotating the drums, and also varying the rotating torque of the drums during contra-rotation to ensure that a constant tension is imposed on the cable during deployment/retrieval.
The novel features of the present invention will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similarly-referenced characters refer to similarly-referenced parts, and in which:
Referring initially to the
A Hydraulic Power Unit (HPU) 20 can be plumbed through a Hydraulic Control Circuit (HCC) to rotate hydraulic motors 19a, 19b and drums 14 and 16, as shown in
In several embodiments, the cable array 22 to be deployed or recovered from the water can be wound multiple times around drums 14, 16 in a figure eight configuration, as shown in
Referring now to
Each guide vane is further formed with an inner leading edge 30 and an outer leading edge 32. Inner leading edge 30 has a radius of curvature that conforms to the shape of drums 14, 16. As further shown in
Referring now to
The methods according to several embodiments can further include the step of threading the cable around first drum 14, through guide vanes 18 and around second drum 16 in a figure-eight configuration, as indicated by block 708 and as shown in
The use of the terms “a” and “an” and “the” and similar references in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of any ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
This invention (Navy Case No. 100249) is assigned to the United States Government and is available for licensing for commercial purposes. Licensing and technical inquires may be directed to the Office of Research and Technical Applications, Space and Naval Warfare Systems Center, Pacific, Code 72120, San Diego, Calif. 92152; voice (619) 553-2778; email T2@spawar.navy.mil.