Concentric cutting assembly, concentric cutting systems, and net penetration method

Abstract

The problem of penetrating through nets and other objects is solved by cutting the object using concentric cutters in which a rotatable cutter having floating teeth rotates concentrically about a stationary cutter having fixed teeth. The object is cut by a severing action caused by the floating teeth of the rotatable cutter sliding against the fixed teeth of the stationary cutter. Embodiments of the invention include a UUV system for penetrating through fishing nets and other objects, concentric cutting assemblies for use in the UUV system and other systems, and a method for penetrating through fishing nets and other objects. A UUV system in accordance with an embodiment of the invention has a concentric cutting assembly at the forward end and a propulsor at the aft end. The concentric cutting assembly integrates seamlessly within the UUV housing and is deployed from the forward end of the UUV, enabling the UUV to quickly and efficiently penetrate through objects blocking its path.

What is claimed as new and desired to be protected by Letters Patent of the United States is: 
     
         1 . A cutting assembly, comprising:
 a first cutter having a plurality of fixed teeth;   a second cutter axially aligned with and able to rotate concentric with the first cutter; and   at least one floating tooth flexibly mounted to the second cutter, the at least one floating tooth being kept substantially against at least one of the plurality of fixed teeth when the second cutter rotates.   
     
     
         2 . The cutting assembly of  claim 1 , wherein the second cutter alternates rotating clockwise and counter-clockwise for a predetermined time period. 
     
     
         3 . The cutting assembly of  claim 1 , wherein the first and second cutters have cylindrical bodies. 
     
     
         4 . The cutting assembly of  claim 3 , wherein the second cutter can rotate concentrically within the first cutter. 
     
     
         5 . The cutting assembly of  claim 3 , wherein each of the at least one floating tooth is attached to the second cutter such that each floating tooth extends from and in a direction parallel to a center axis of the cylindrical body of the second cutter. 
     
     
         6 . The cutting assembly of  claim 5 , wherein the plurality of fixed teeth extends from the cylindrical body of the first cutter and in the direction parallel to the center axis of the cylindrical body of the second cutter. 
     
     
         7 . The cutting assembly of  claim 3 , further comprising a plurality of mounted bearing plates for the purpose of keeping the first and second cutters axially aligned. 
     
     
         8 . The cutting assembly of  claim 3 , further comprising a plurality of bearing plates mounted about the second cutter for the purpose of keeping the first and second cutters axially aligned. 
     
     
         9 . The cutting assembly of  claim 3 , further comprising a plurality of bearing plates mounted about the first cutter for the purpose of keeping the first and second cutters axially aligned. 
     
     
         10 . The cutting assembly of  claim 6 , further comprising springs for flexibly mounting each of the at least one floating tooth to the second cutter. 
     
     
         11 . The cutting assembly of  claim 10 , wherein the springs for flexibly mounting each of the at least one floating tooth to the second cutter are wavy springs. 
     
     
         12 . The cutting assembly of  claim 1 , wherein the first and second cutters have triangular bodies. 
     
     
         13 . The cutting assembly of  claim 1 , wherein the first and second cutters have square bodies. 
     
     
         14 . The cutting assembly of  claim 1 , wherein the first and second cutters are formed from carbon fiber. 
     
     
         15 . The cutting assembly of  claim 1 , wherein the plurality of fixed teeth are of substantially equal length. 
     
     
         16 . The cutting assembly of  claim 1 , wherein the plurality of fixed teeth are formed as blades having an angled cutting edge. 
     
     
         17 . The cutting assembly of  claim 1 , wherein the plurality of fixed teeth have rounded blade tips. 
     
     
         18 . The cutting assembly of  claim 1 , wherein the plurality of fixed teeth have a same unidirectional cutting edge. 
     
     
         19 . The cutting assembly of  claim 18 , wherein the at least one floating tooth has an angled cutting edge that opposes the unidirectional cutting edge of the plurality of fixed teeth. 
     
     
         20 . The cutting assembly of  claim 1 , wherein the at least one floating tooth has a serrated cutting edge. 
     
     
         21 . The cutting assembly of  claim 1 , wherein the plurality of fixed teeth are longer than the at least one floating tooth. 
     
     
         22 . A cutting assembly, comprising:
 dual concentric cylinders comprising a rotatable inner cylinder within a non-rotatable outer cylinder;   a plurality of bearing plates mounted about the non-rotatable outer cylinder for axially aligning the dual concentric cylinders;   a plurality of floating blades mounted about the rotatable inner cylinder such that each floating blade protrudes from the rotatable inner cylinder in a direction parallel to a center axis of the dual concentric cylinders;   a plurality of stationary blades spaced apart along the non-rotatable outer cylinder such that each stationary blade protrudes from the non-rotatable outer cylinder in the direction parallel to the center axis of the dual concentric cylinders, each stationary blade having a same unidirectional cutting edge; and   a plurality of springs for mounting the plurality of floating blades about the rotatable inner cylinder and for keeping the floating blades substantially against the stationary blades as the rotatable inner cylinder rotates within the non-rotatable outer cylinder.   
     
     
         23 . The cutting assembly of  claim 22 , wherein plurality of the floating blades have cutting edges angled in a direction that causes the plurality of floating blades to act as shears when rotating past the plurality of stationary blades. 
     
     
         24 . The cutting assembly of  claim 22 , wherein the plurality of floating blades are removable for easy maintenance. 
     
     
         25 . The cutting assembly of  claim 22 , wherein the plurality of bearing plates are adjustable in depth and tilt. 
     
     
         26 . The cutting assembly of  claim 22 , wherein six bearing plates are mounted in pairs about the non-rotatable outer cylinder for the purpose of axially aligning the dual concentric cylinders. 
     
     
         27 . An unmanned underwater vehicle, comprising:
 an outer hull; and   a cutting assembly located within the outer hull, the cutting assembly comprising:
 a stationary cutter having a cylindrical body and a plurality of fixed teeth extending from one end of the stationary cutter; 
 a floating cutter axially aligned with the stationary cutter, the floating cutter being able to rotate concentrically within the stationary cutter; and 
 a plurality of floating teeth flexibly arranged about and extending from one end of the floating cutter, the plurality of floating teeth and the plurality of fixed teeth extending in a same direction, and the plurality of floating teeth being kept substantially against at least one of the plurality of fixed teeth when the floating cutter rotates. 
   
     
     
         28 . The unmanned underwater vehicle of  claim 27 , wherein the cutting assembly further comprises a microcontroller for controlling a plurality of cutting assembly functions. 
     
     
         29 . The unmanned underwater vehicle of  claim 28 , wherein the plurality of cutting assembly functions includes setting a cutter run time, a cutter retrieval time, and a cutter deployment speed. 
     
     
         30 . The unmanned underwater vehicle of  claim 27 , wherein the cutting assembly further comprises a plurality of bearing plates mounted about the stationary cutter for the purpose of keeping the stationary and floating cutters axially aligned. 
     
     
         31 . The unmanned underwater vehicle of  claim 27 , wherein the cutting assembly further comprises an internal ring gear mounted on an inside surface of the floating cutter, a motor and switch assembly mounted to the stationary cutter, and an external gear mounted to the motor and meshing with the internal ring gear for rotating the floating cutter concentrically within the stationary cutter. 
     
     
         32 . The unmanned underwater vehicle of  claim 27 , wherein the cutting assembly further comprises springs for flexibly arranging each of the plurality of floating teeth about the floating cutter. 
     
     
         33 . The unmanned underwater vehicle of  claim 32 , wherein a bi-directional cutting action results when the plurality of floating teeth slides against the plurality of fixed teeth. 
     
     
         34 . The unmanned underwater vehicle of  claim 27 , wherein the cutting assembly further comprises a plurality of roller bearings for extending and retracting the floating and stationary cutters. 
     
     
         35 . The unmanned underwater vehicle of  claim 27 , wherein the cutting assembly further comprises a plurality of slide rails mounted about an inside surface of the outer hull for extending and retracting the floating and stationary cutters. 
     
     
         36 . The unmanned underwater vehicle of  claim 35 , wherein the cutting assembly further comprises an actuator in contact with the stationary cutter and the outer hull, and an actuator controller for controlling the actuator for extending and retracting the floating and stationary cutters from a forward end of the outer hull. 
     
     
         37 . The unmanned underwater vehicle of  claim 36 , wherein the actuator comprises a plurality of actuators. 
     
     
         38 . The unmanned underwater vehicle of  claim 27 , wherein the plurality of fixed teeth are substantially equally spaced about the stationary cutter. 
     
     
         39 . The unmanned underwater vehicle of  claim 27 , wherein the floating and stationary cutters have thin walled cylindrical bodies. 
     
     
         40 . The unmanned underwater vehicle of  claim 39 , wherein three floating teeth are arranged about the floating cutter such that no more than one of the three floating teeth are cutting at the same time. 
     
     
         41 . The unmanned underwater vehicle of  claim 27 , wherein the floating cutter has a triangular body that fits concentrically within the cylindrical body of the stationary cutter. 
     
     
         42 . The unmanned underwater vehicle of  claim 27 , wherein the floating cutter has a square body that fits concentrically within the cylindrical body of the stationary cutter. 
     
     
         43 . The unmanned underwater vehicle of  claim 27 , wherein the floating cutter has a Y-shaped body that fits concentrically within the cylindrical body of the stationary cutter. 
     
     
         44 . The unmanned underwater vehicle of  claim 27 , wherein the floating cutter has a foam inner center for natural buoyancy. 
     
     
         45 . The unmanned underwater vehicle of  claim 27 , wherein the cutting assembly is stored in a space inside the unmanned underwater vehicle between a forward looking sonar and the outer hull. 
     
     
         46 . A method of cutting an object using dual concentric cutters comprising a first cutter having at least one floating tooth and a second cutter having a plurality of fixed teeth, the method comprising the steps of:
 rotating the first cutter concentrically within the second cutter;   moving the dual concentric cutters toward the object;   capturing the object with at least one of the plurality of fixed teeth; and   cutting the object using the at least one floating tooth, the object being cut by a severing action caused by the at least one floating tooth sliding against the plurality of fixed teeth.   
     
     
         47 . A method of penetrating an object by an underwater vehicle using a cutting assembly comprising dual concentric cutters, the method comprising the steps of:
 detecting the object in a path of the underwater vehicle;   deploying the cutting assembly such that the dual concentric cutters extend out from a forward end of the underwater vehicle;   rotating a rotatable cutter of the cutting assembly, the rotatable cutter having a plurality of spring-mounted floating teeth;   capturing the object with one or more fixed teeth extending from a non-rotatable cutter of the cutting assembly;   cutting the object as at least one of the plurality of spring-mounted floating teeth slides against the one or more fixed teeth; and   retracting the dual concentric cutters into the underwater vehicle.   
     
     
         48 . The method of  claim 47 , wherein the step of detecting the object is determined by a speed signal provided by the underwater vehicle.