This invention relates generally to cable cutters. More specifically, but without limitation thereto, this invention relates to an underwater cable cutter that uses water pressure to cut a cable underwater.
The design and use of cable cutters for ocean environments has become of increasing importance to marine engineering. Presently, the use of such cutters is desired for all depths of the world's oceans. Cable cutters are of great interest to the U.S. Navy. One major Navy application is in minesweeping operations.
The design and construction of cable cutters fall within a wide area of engineering disciplines. The general method for cable cutting is a mechanical technique usually involving severing a cable or wire placed between an anvil and a cutter. In some cases scissor-like devices are used. Operation of the cable cutter has included direct, hands-on, manipulation by a diver as well as remote operation of a cutter. Mechanical and explosive techniques are common. Generally, such cable cutters have been designed to be expendable in that they are to be used only once and/or are allowed to be lost or destroyed when operated.
Originally, cable cutters were designed mostly for cutting simple wire ropes and electrical cables. Modern state-of-the-art electrical cable construction however has resulted in the use of KEVLAR as a strength member. KEVLAR is a tough synthetic fiber that is usually difficult to cut by ordinary scissor mechanisms. Consequently, many new designs for various types of cable cutters have been presented. These generally incorporate powerful anvil/cutter blade mechanisms.
Cable cutters designed for use at great ocean depths have been required to be heavy and bulky in order to protect certain pressure sensitive components from high hydrostatic pressures.
This is particularly true where hydraulic systems are used to provide a powerful cutting force. Therefore, there remains a need to overcome one or more of the limitations in the above-described art.
An underwater cable cutter apparatus (“cable cutter”) comprises an apparatus for cutting a cable, wire or other line located underwater. The apparatus includes a body with a lid and a base. A piston is located within the body, and a piston rod is coupled to the piston. A cutting element is pivotally coupled to a distal end of the piston rod and also pivotally coupled to the base. Upon actuation, water is introduced through the lid and into the body, moving the piston and piston rod and thereby operating the cutting element. The cable, wire or line to be cut is positioned in a cable holder, and the cutting element cuts the cable, wire or line when operated by the piston rod.
A feature of the cable cutter is that it is actuated by water pressure. That is, the cable cutter severs cables, wires or other types of lines that are underwater by using only the surrounding water pressure to generate the force required to cut the cable.
These and other features and advantages will be appreciated from review of the following Description, along with the accompanying figures in which like reference numerals are used to describe the same, similar or corresponding parts in the several views of the drawings.
It will be recognized that some or all of the Figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown. The Figures are provided for the purpose of illustrating one or more embodiments with the explicit understanding that they are offered by way of example only and are not intended to limit the scope of the invention.
Referring now to
Because the density of water is over 800 times greater than the density of air (at standard temperature and pressure), it will be appreciated that a substantial cutting force can be generated by immersing the cable cutter 10 in only a relatively small depth of water. Besides originally providing body 16 with sea level air pressure, the air located within the interior of the body 16 may be initially eliminated, or substantially eliminated, creating a vacuum, or partial vacuum. Such a low pressure environment can be selected for just that part of cutter 10 identified in the figure as air chamber 28. Thus an even greater pressure differential can be selected to exist between the interior of the body 16 and the exterior of the body 16.
The cutting process is initiated by removing either an exterior actuator 30 or an interior actuator 32 from lid aperture 34. An O-ring, D-ring or other suitable sealing element is positioned between the actuators 30/32 and lid aperture 34 to seal against water from entering the water chamber 22 when the actuators 30/32 are in position. Once actuator 30 or 32 is removed, water flows into water chamber 22 and pushes upon piston 12. Because the volume on the other side of the piston 12, shown in
As shown in
Referring to
Referring now to
In one embodiment piston 12 is fitted with two sealing rings 48 that may be O-rings, D-rings or other types of sealing elements that impede the passage of water. It will be appreciated that other numbers of sealing rings 48 may be employed. The sealing rings 48 may be the same diameter and thickness, or they may differ in diameter and thickness.
A lid retainer 50 secures lid 42 to body 16. As shown in
As shown in
Pivot pin 54 allows elongate lever cutting element 20 to pivot about pivot pin 54 while remaining attached to base 18. Cutting element 20 includes a cutting edge or surface 62, as shown in
Referring now to
In one embodiment, wherein an exterior actuator 30 is employed, the exterior actuator may be removed via a buoy attached to the actuator by a cable or directly by a cable (neither shown) so that when the actuator 30 is pulled free from lid 42, water is allowed to pass through lid aperture 34. Alternatively, in another embodiment, an interior actuator 32 may be employed, this interior actuator also being positioned in lid aperture 34. An acoustic release, designed to function upon receiving an acoustic signal, may be made integral with interior actuator 32. Upon receiving a designed acoustic signal, interior actuator 32 separates from lid aperture 34 so that water pressure forces the interior actuator into the interior of body 16. Consequently, water is allowed to push against piston 12 thereby moving the piston and attached piston rod 14 toward base 18. It will be appreciated that other methods may be employed to seal, and subsequently un-seal lid aperture 34.
When water is introduced into water chamber 22, the water pressure forces piston 12 away from lid 42 and towards base 18, thereby decreasing the size of air chamber 28. For example, in one embodiment of cable cutter 10, body 16 may have an internal volume of approximately 43 cubic inches, and the surface area of piston 12 is approximately 10 square inches. It will be appreciated that the internal volume of body 16, the surface area of piston 12, and other dimensions of the cable cutter 10 may vary from these example dimensions.
When piston 12 is driven by water pressure, cutting element 20 pivots about pivot pin 54 and piston rod 14 pushes the other end of cutting element 20 from base 18 (these actions shown by arrows in
Because water pressure is used as an operating force to cut the cable, the underwater cable cutter disclosed herein is reliable, and circumvents a more complex hydraulic system as well as avoids the inherent complexities of dangerous explosives. Body 16, base 18, lid 42, cutting element 20, piston 12, piston rod 14, lid retainer 50, cable holder 24, cable lock 26, and other components of the underwater cable cutter 10 may be constructed of metal, metal alloys (such as steel and stainless steel), plastics, silicone rubber, and other suitable elements.
Thus, it is seen that an apparatus and method for cutting a cable located underwater is provided. While specific embodiments have been described, it is evident that many alternatives, modifications, permutations and variations will become apparent to those of ordinary skill in the art in light of the foregoing description. Obviously, many modifications and variations are possible in light of the above description. It is therefore to be understood that within the scope of the claims the inventions may be practiced otherwise than as has been specifically described.
This invention (Navy Case No. 97355) was developed with finds from the United States Department of the Navy. Licensing inquiries may be directed to Office of Research and Technical Applications, Space and Naval Warfare Systems Center, San Diego, Code 2112, San Diego, Calif. 92152; telephone (619) 553-2778; email: T2@spawar.navy.mil.
Number | Name | Date | Kind |
---|---|---|---|
1915435 | Miller | Jun 1933 | A |
3763738 | Temple | Oct 1973 | A |
4016728 | Mason | Apr 1977 | A |
4020780 | Shumaker et al. | May 1977 | A |
4040376 | Giebel | Aug 1977 | A |
4120246 | Sabranski et al. | Oct 1978 | A |
4128071 | Layman et al. | Dec 1978 | A |
4463496 | Reich et al. | Aug 1984 | A |
4805547 | Matsuzaki et al. | Feb 1989 | A |
5042413 | Benoit | Aug 1991 | A |
5419272 | Backstein et al. | May 1995 | A |
6038807 | Taylor | Mar 2000 | A |
6397948 | Williams et al. | Jun 2002 | B1 |