Cutters Patents (Class 114/42)
  • Patent number: 11926400
    Abstract: A bottom touching assisting device suitable for deep-sea submersibles and an implementation method thereof are provided. Four support columns are arranged within a mounting box body at a bottom of a deep-sea submersible, the support columns and the mounting box body are connected in a sliding manner through sliders, and the support column is sleeved with a threaded sleeve in a threaded connection manner. In conjunction with a drive component and a pressing mechanism, smooth vertical movement of the support column is achieved when the threaded sleeve rotates. This allows a bottom end of the support column to extend from the mounting box body.
    Type: Grant
    Filed: December 6, 2023
    Date of Patent: March 12, 2024
    Assignee: Qingdao Institute of Marine Geology
    Inventors: Xilin Zhang, Nengyou Wu, Qingsheng Liu, Hong Cao, Ang Li, Zhilei Sun, Cuiling Xu, Ye Chen, Sinan Xu, Jianjun Miao
  • Patent number: 9499238
    Abstract: A portable ice crusher assembly to be mounted on the bow of an icebreaker. The main sections are a deck support assembly, a deck power assembly and a front support assembly with a hanging container with weights within, and sharp pointed spikes at its bottom. The ice crusher assembly breaks up the ice in front of the icebreaker by dropping the container onto it. Instead of breaking the ice with a ship's hull an ice crusher assembly can be used.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: November 22, 2016
    Inventor: Nathanial Henry Lewis
  • Patent number: 9316092
    Abstract: A marine vessel for hydrocarbon exploration and methods of utilizing the same. In some embodiments, the vessel is enhanced with deployable and adjustable land propulsion mechanisms controlled by an active system to maintain position when on top of a drifting ice floe, water propulsion devices connected to the vessel hull capable of station-keeping in open water and/or within broken sea ice, sufficient power and flexibility to enable riding an ice floe, and at least one deployable ice hole cutter to open a channel through the ice floe.
    Type: Grant
    Filed: July 12, 2013
    Date of Patent: April 19, 2016
    Assignee: ExxonMobil Upstream Research Company
    Inventor: Adel H. Younan
  • Patent number: 9297920
    Abstract: A system for aquatic seismic prospecting includes at least one submerged mobile seismic source for creating a disturbance transmitted through an aquatic medium in the form of waves and at least one cable having a plurality of sensors for collecting waves transmitted by the at least one submerged mobile seismic source and reflected from geological layers beneath the aquatic medium. The system also includes means for detecting and measuring the reflected waves and means for placing the at least one cable under tension, the tensioning means attached to ends of the at least one cable and the tensioning means keeping the at least one cable in a pseudo-stationary position. These is also means for holding the at least one cable at a substantially constant depth greater than approximately 5 meters.
    Type: Grant
    Filed: December 29, 2009
    Date of Patent: March 29, 2016
    Assignee: KIETTA
    Inventor: Michel Manin
  • Publication number: 20150047543
    Abstract: A propulsor arrangement for operation in icy as well as open water, for a marine vessel having a hull (S) with a center line (CL) extending between a forward end (3) and an aft end (4), said propulsor arrangement comprising a plurality of azimuthing thrusters (1A-ID) having a centre of rotation (CR) and a longest lateral distance (R) that it protrudes from said centre of rotation (CR), preferably having at least one azimuthing thruster (1A-ID) with a propeller (2) arranged to act in ice, wherein said propulsor arrangement includes at least three azimuthing thrusters (1A, 1B, 1G) positioned close to one end (3, 4) of said hull (S), including at least one pair (1A, 1B) positioned substantially symmetrical in relation to said center line (CL) along a transversal line in relation to said center line (CL) a first distance (Q1) apart a and at least one azimuthing thruster (1G) positioned closer to said end (3, 4) and said centerline (CL) and positioned a longitudinal distance (P1) away from said transversal line.
    Type: Application
    Filed: February 7, 2013
    Publication date: February 19, 2015
    Applicant: ROLLS ROYCE AB
    Inventor: Thomas Henriksen
  • Publication number: 20110239923
    Abstract: A vessel and method for breaking ice drifting in a predominant direction relative to an offshore installation such as a drilling vessel. The vessel is used to deploy an anchor in a position at a distance from the offshore installation and in a direction which, seen from the offshore installation, is substantially in parallel with the direction of movement of the ice. By means of the machinery of the vessel, the direction of the anchor line is adjusted and so is the orientation of the vessel relative to the anchor line to the effect that the propellers can be used to crush and dispose of the ice without using motive energy to hold the vessel against the pressure of the ice.
    Type: Application
    Filed: March 31, 2011
    Publication date: October 6, 2011
    Inventor: Niels Peter Elmbo
  • Patent number: 4942837
    Abstract: An icebreaker hull having laterally projecting hull components which define inclined upwardly and rearwardly sloped faces arranged in part above and in part below the vessels normal water line, and each hull component further including a longitudinally extending face cooperating with the inclined face to define a cutting edge. At least a second pair of similar projecting hull components adjacent the first components to define a second cutting edge downstream of the first cutting edge. One or more of these hull components may be movable from and to positions where they are stowed in streamline relationship to the hull.
    Type: Grant
    Filed: January 26, 1989
    Date of Patent: July 24, 1990
    Assignee: Thyssen Nordseewerke GmbH
    Inventors: Jens-Holger Hellmann, Richard Holscher, Hermann J. Janssen, Alfred Kleemann, Karl-Heinz Rupp, Joachim Schwarz, Gunter Varges, Heinrich Waas
  • Patent number: 4826353
    Abstract: A drag unit to absorb the kinetic energy from large floating bodies of ice is constructed around a buoyancy chamber (14). The buoyancy chamber is attached to a torque arm (16) and this is secured at its remote end to an anchor line (6). The buoyancy chamber supports a rotatable drag wheel (20) at either end. The drag wheels each have a plurality of sharp impeller blades on their outer surfaces. The drag wheels are impeded from rotation by brakes (40) attached to the buoyancy chamber (14), the brakes being energized hydraulically from a high pressure gas chamber (71). When a large mass of ice contacts the drag wheels, a braking force determined by the pressure in the gas chamber (71) is applied to the ice, thereby reducing its speed.
    Type: Grant
    Filed: September 16, 1987
    Date of Patent: May 2, 1989
    Inventor: John A. Statham
  • Patent number: 4718871
    Abstract: An upper and a lower blade are fixed together at an adjustable angle and have means for mounting same on the leading edge of the propeller drive housing of an inboard/outboard motor to cut kelp and other seaweed which would otherwise foul the prop and clog the cool, sea water input vents. The cutter has adjustable brackets which will accommodate a wide variety of different types of propeller drive housings, and will accommodate outboard motors as well as inboard motors, and will even fit on the advance edge a sailboat keel. In one embodiment, it has a combination brace/mesh screen which extends from the cutter to the propeller drive housing in front of the cooling water inlets to keep bits of seaweed and other debris from entering and clogging the cooling system, causing overheating the destruction of the motor.
    Type: Grant
    Filed: March 24, 1986
    Date of Patent: January 12, 1988
    Inventor: Eli Mendelevitch
  • Patent number: 4636607
    Abstract: In order to perform an ice-breaking operation more readily or with a defined geometry, an ice breaking aid is employed by virtue of which the ice is irradiated with high-frequency oscillations such as phonons or photons prior to the ice-breaking operation proper.
    Type: Grant
    Filed: May 13, 1985
    Date of Patent: January 13, 1987
    Assignee: M.A.N. Maschinenfabrik Augsburg-Nurnberg Aktiengesellschaft
    Inventors: Axel Hayd, Peter Meinke, Martin Maurer, Joachim Schwarz
  • Patent number: 4615645
    Abstract: A hollow curved auger is provided for simultaneously laying and trenching a pipeline, as from the surface of an ice-covered body of water. The pipeline passes through the auger which comprises rotary teeth encircling the pipeline and turning in opposed directions. The depth and direction of pipeline trenching and burial are controlled by varying the longitudinal force in the pipe and rotational orientation of the auger.
    Type: Grant
    Filed: May 6, 1985
    Date of Patent: October 7, 1986
    Assignee: Shell Oil Company
    Inventor: Carl G. Langner
  • Patent number: 4523876
    Abstract: During winter construction of offshore Arctic pipelines, it is frequently necessary to cut an ice slot in order to lay a pipeline on the sea bottom. Once such slots are cut, they rapidly freeze over, so that it is necessary to remove ice from the slot during the pipelaying time span. The present invention provides a method and apparatus for removing the newly formed ice from the ice slot. An inclined plane, sized to fit within the ice slot width to be maintained, penetrates below the surface of the water within the slot and to a depth at or below the underside of the newly formed ice on the water's surface. By moving the plane along the surface, the ice is raised, broken, and then conveyed upward and then to one side out of the ice slot as spoil.
    Type: Grant
    Filed: December 2, 1983
    Date of Patent: June 18, 1985
    Assignee: Shell Oil Company
    Inventor: Dean P. Hemphill
  • Patent number: 4436046
    Abstract: An icebreaker hull is disclosed having cutting edges and sloping ramps that substantially surround the icebreaker's forefoot and taper as they continue aft along the sides of the hull. The cutting edges produce grooves in the underside of the ice to reduce the resistance of the ice to breaking. The ramps are used to break the ice near the bow of the icebreaker and to remove the broken pieces from the water. The pieces of broken ice move along the sloping ramps as the icebreaker continues its forward movement through the ice field. The tapered portions of the ramps provide for the broken pieces of ice to be deposited substantially in windrows on the surface of the unbroken ice field. Thereafter, sweep assemblies that extend away from the hull on both the port and starboard sides are positioned to move the windrows further away from the substantially ice-free channel that is formed behind the icebreaker as it moves forward through the ice field.
    Type: Grant
    Filed: February 1, 1982
    Date of Patent: March 13, 1984
    Inventor: William W. Braley
  • Patent number: 4429653
    Abstract: In order to assist ice chunks along preferred discharge paths in a large scale ice disaggregation system employing counter-rotating twin cutters, water is pumped tangentially across the trailing edges of the counter-rotating cutters against the direction of rotation to overcome the centrifugal action which tends to cause ice jamming. Secondary hydro-jets may be employed to further urge the ice chunks away from the vessel into the open region previously cut.
    Type: Grant
    Filed: February 1, 1982
    Date of Patent: February 7, 1984
    Assignee: Suncor, Inc.
    Inventors: George W. Morgan, Vernon F. Wetzel
  • Patent number: 4422399
    Abstract: In an ice disaggregation system employing teeth affixed to a bracket which is spirally disposed around the outer periphery of a cylindrical rotating drum and held in spaced relationship therefrom, the cutting capacity is improved by tilting the plane of each tooth with respect to the drum's axis of rotation such that each incremental section of ice which a tooth engages is subjected to a bending force about a pivot near an area from which ice has been removed and is therefore relatively weak. As a result, the ice readily fractures in relatively large chunks.
    Type: Grant
    Filed: September 7, 1978
    Date of Patent: December 27, 1983
    Assignee: Suncor, Inc.
    Inventor: George W. Morgan
  • Patent number: 4365571
    Abstract: Improved apparatus is disclosed for supporting the cutting teeth on the periphery of a rotating cylindrical drum ice cutter affixed to a floating arctic structure. The cutting teeth are individually removably affixed to brackets which extend spirally (either continuously or in segments) around the drum periphery and are supported in spaced relationship radially outwardly therefrom by very sturdy struts. Several benefits are obtained with this configuration: (1) hydrodynamic drag is minimized; (2) the teeth-support structure can be made more rugged than individual ones for each tooth; (3) the teeth can be configured for a minimum of replaceable material at the cutting tips; (4) more free volume is available around the drum periphery for disposal flow of disaggregated material and (5) tooth spacing can be readily adjusted for optimum performance according to requirements.
    Type: Grant
    Filed: September 7, 1978
    Date of Patent: December 28, 1982
    Assignee: Suncor Inc.
    Inventor: George W. Morgan
  • Patent number: 4350114
    Abstract: A tanker having a submersible hull has a mast extending above the hull supporting a bridge section. The base of the mast is journaled in the hull for rotation about a vertical axis. The bridge section is rotatably supported on the mast. Drive means rotates the mast relative to the hull and the bridge section such that the hull and bridge section remain aligned while the angular position of the mast is changed. Rotary ice cutters are positioned along one side of the mast and are positioned relative to the surrounding ice by rotation of the mast so as to be aligned with the direction in which the ice encroaches on the mast.
    Type: Grant
    Filed: March 17, 1980
    Date of Patent: September 21, 1982
    Assignee: Sea-Log Corporation
    Inventor: Joseph F. Schirtzinger
  • Patent number: 4348059
    Abstract: In an ice disaggregating system employing one or more rotating drums with peripherally positioned ice engaging teeth, the improvement in which the teeth are multiple-tined. In one configuration, each tooth has two equal length, pointed tines. In a preferred configuration, a long pointed central tine is flanked by a pair of shorter pointed tines.
    Type: Grant
    Filed: September 7, 1978
    Date of Patent: September 7, 1982
    Assignee: Sun Oil Company, Ltd.
    Inventor: George W. Morgan
  • Patent number: 4294183
    Abstract: In order to improve the efficiency and reliability of the cutter units employed in large scale ice disaggregation systems, a cutter configuration is employed characterized by an outwardly extending arm which sweeps rearwardly from the direction of travel to provide clearance for ice chunks and then sharpwardly forwardly to terminate in an ice-engaging portion. The ice-engaging portion includes a relatively long and narrow central "pick" portion for breaking very cold ice, chisel-like cutting edges directed to each side of the base of the "pick" portion to fracture cold ice as well as warm ice, and an inverted skate portion which cleaves the ice and promotes passage of the ice chunks around the tooth structure to facilitate clearing.
    Type: Grant
    Filed: April 14, 1980
    Date of Patent: October 13, 1981
    Assignee: Suncor Inc.
    Inventor: George W. Morgan
  • Patent number: 4276845
    Abstract: An ice cutting and breaking vessel is disclosed for providing a shipping channel through an ice layer. The bow of the vessel is provided with a plurality of reciprocating cutting blades for cutting the ice into slabs. The slabs of ice slide under the bow and are pushed under the surrounding ice layer by a wedge-shaped prow depending from the bow and by water discharged laterally from the prow. The vessel is also provided with an emergency ballast tank, located above the water line, which can be quickly emptied through large ports. A pair of grapnels with attached cables may also be provided which are shot from the vessel. When the grapnel hits the ice layer, it pierces the ice and becomes wedged under the ice layer. Using the cables to pull on, the vessel can then haul itself toward the grapnels.
    Type: Grant
    Filed: August 17, 1979
    Date of Patent: July 7, 1981
    Inventor: W. F. Spanner
  • Patent number: 4230423
    Abstract: A rotary ice-breaking body having a spiral rotary blade is attached to a structure for use in icy waters at a part falling in contact with an ice lump or ice floe. The rotary blade is actuated to bite into the ice lump and to lift up or press down the ice lump. The ice lump is broken by the flexural stress and the structure is protected from influences of the ice lump. One rotary ice-breaking body may be disposed to constitute the outer periphery of the structure. Alternately, a plurality of rotary ice-breaking bodies may be disposed to surround the structure so that they are driven and rotated simultaneously or independently.
    Type: Grant
    Filed: November 23, 1977
    Date of Patent: October 28, 1980
    Assignee: Mitsui Engineering & Shipbuilding Co., Ltd.
    Inventors: Masanao Oshima, Mikihisa Komoto, Shoichi Yabuki, Tsuneo Inokawa
  • Patent number: 4198917
    Abstract: Disclosed are ice-breaking units for ships adapted to be installed at the bow and/or bottom portion of the ship's hull, consisting of two ice-breaking units each of which can be reversibly driven independently of each other, for performing ice-breaking and/or propulsion of the ship. The ice-breaking unit has a screw-like body having a spiral blade wound thereabout. The ice-breaking units may be disposed at the bow portion, at both sides of the longitudinal center line of the ship, in parallel with or normal to the latter, or may be arranged to have a propulsion portion and an ice-breaking portion, respectively. The two screw-like bodies may be driven simultaneously in the same direction or reversed, or may be rotated in the opposite directions, to provide thrusts to move the ship in any direction of ahead/astern and port/starboard.
    Type: Grant
    Filed: August 9, 1977
    Date of Patent: April 22, 1980
    Assignee: Mitsui Engineering and Shipbuilding Co., Ltd.
    Inventors: Masanao Oshima, Mikihisa Komoto, Shoichi Yabuki, Tsuneo Inokawa
  • Patent number: 4170187
    Abstract: A mobile drilling and production platform for arctic regions in which a hull having a deck forming the production platform is supported on a first set of parallel runners secured to the underside of the hull and extending fore and aft with spaces between the runners. A second set of parallel segmented runners are secured to the underside of the hull and extend perpendicular to the first set of runners, the second set of runners including a plurality of sections positioned in the spaces between the first set of runners. A plurality of rotating ice cutters are mounted on the hull and extend down in front of the ends of each of the runners, the ice cutters cutting channels in the ice in which the runners move and support the hull. One set of runners is vertically movable from the hull relative to the other set of runners whereby the weight of the hull can be transferred from one set of runners to the other to permit movement of the platform along two perpendicular axes or coordinance of motion.
    Type: Grant
    Filed: January 26, 1978
    Date of Patent: October 9, 1979
    Assignee: Sea-Log Corporation
    Inventor: Joseph F. Schirtzinger
  • Patent number: 4152999
    Abstract: An ice-breaking apparatus for use in ships and barges operating on icy waters, including nozzles for jetting high pressure fluid, is disclosed. By impinging force or cavitation caused by the high pressure fluid jetted from the nozzles, grooves or cracks are formed on an ice floe, and then, the ice floe is broken from these grooves or cracks by the hull. This ice-breaking apparatus facilitates breakage of ice floes or the like, and when this ice-breaking apparatus is attached, ships or barges for operation on icy waters can be built without increasing dimensions or propulsion powers particularly for navigation on icy waters. The ice-breaking apparatus includes echo distance measuring apparatus for automatically controlling and maintaining the nozzles at optimum positions from the ice-surface.
    Type: Grant
    Filed: December 5, 1977
    Date of Patent: May 8, 1979
    Assignee: Mitsui Engineering and Shipbuilding Co., Ltd.
    Inventors: Masanao Oshima, Hiroshi Tabuchi, Tsuneo Inokawa
  • Patent number: 4137986
    Abstract: An arctic vehicle is provided for the rapid transport of goods, machinery, and personnel over ice, snow and frozen ground surfaces.The vehicle is supported partially while at rest and/or under way by a cushion of air which is entrained by a system of seals. Seals along the sides terminate in runners for guiding and partially supporting the vehicles. A cutter system is deployed in front of each runner to form smooth running tracks or furrows over ice, snow, and frozen ground surfaces. A transverse cutter may be deployed in front of the forward transverse seal for removing major ice protrusions between the runners, to reduce seal leakage and wear, and improve ride characteristics. The cut tracks, in addition to providing smooth transit, engage the runners and side seals to prevent lateral shifting of the vehicle by the action of crosswinds and sideslopes.The vehicle may be self-propelled or towed.
    Type: Grant
    Filed: June 17, 1977
    Date of Patent: February 6, 1979
    Assignee: Sea-Log Corporation
    Inventor: Joseph F. Schirtzinger
  • Patent number: 4102288
    Abstract: A mobile monopod operations platform for use in ice covered seas and adapted for carrying out two modes of ice disaggregation, either or both such modes being selectively useable during either transit or relatively stationary operations. An ice breaker bow is employed in conjunction with simulated pitching and heaving brought about by the programmed use of a plurality of fully vectorable thrusters on a submersible hull. At the stern of the monopod structure, counter-rotating cutting drums are utilized for ice disaggregation in a mode particularly useful when the ice is thick. Topside of the bow and cutter area, an enclosed, generally circular, superstructure is provided for carrying out the requisite operations while mitigating the adverse effects of high winds.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: July 25, 1978
    Assignee: Sun Oil Company Limited
    Inventors: Holland James Berry, George W. Morgan
  • Patent number: 4077225
    Abstract: An ice cutter movably mounted on a marine structure for cutting encroaching ice floes or ice sheets. A cutter blade is mounted on the structure so that it may be conveniently moved into a position on the structure toward which the ice is moving. Acoustical energy is imparted to the cutter blade which in turn is positioned adjacent the encroaching ice and moved relative to the ice in a manner to cut out a path of unconsolidated ice so that the floe may pass the marine structure without applying destructive forces to the structure.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: March 7, 1978
    Assignee: Sun Oil Company Limited
    Inventors: Gunter J. Lichtenberger, George W. Morgan
  • Patent number: 4070062
    Abstract: A cutting-chipping system comprising an interconnected triaxial array of rotating drums each mounted for independent rotation. Each drum includes a plurality of spaced, outwardly extending teeth to sequentially cut, chip and break particulate mass such as coal or ice engaged by the system. The drums are oriented with no axis of drum rotation parallel to another and in a configuration wherein the direction of cutter travel from one drum is oblique to that of a second drum. In this manner, particulate matter engaged by the system is initially cut and chipped by a first drum to form a series of protuberances and/or weakened sections which, when struck at an oblique angle by a second drum, will chip and break away. The teeth may be comprised of picks, chisels or combinations thereof constructed and adapted for bidirectional rotation. The system may be adapted for applications upon land vehicles, water crafts, floating platforms, and the like.
    Type: Grant
    Filed: November 11, 1976
    Date of Patent: January 24, 1978
    Assignee: Sun Oil Company Limited
    Inventors: George W. Morgan, Joseph E. Zupanick
  • Patent number: 4069783
    Abstract: An ice disaggregation system comprising a multiplicity of aligned and successively longer sledging teeth outwardly extending from a rotatable drum. The drum rotation allows the successively longer teeth to sequentially cut and chip deepening grooves in various forms of particulate matter such as ice or coal engaged by the system. A second form of slugging tooth, outwardly extending from the drum, is provided in generally central alignment between paired rows of sledging teeth. The slugging tooth is positioned to subsequently engage the isolated, ridged sections of ice between successive grooves therein, and for striking said ridges with sufficient force to impart shear fracture thereto. The drum is provided with a plurality of sledging and slugging teeth in staggered groups comprising a spiral configuration along the drum.
    Type: Grant
    Filed: November 11, 1976
    Date of Patent: January 24, 1978
    Assignee: Sun Oil Company Limited
    Inventor: George W. Morgan
  • Patent number: 4022142
    Abstract: An ice cutting system in which a low density fluid, such as air or exhaust gas, is injected into the cutting region. The injection of the low density fluid results in a more efficient cutting operation, and also reduces the buoyancy of the ice chips resulting from the cutting operation. The reduced buoyancy of the ice chips results in the chips sinking in the slurry surrounding the cutter and being dissipated into the water beneath the surrounding ice.
    Type: Grant
    Filed: May 14, 1976
    Date of Patent: May 10, 1977
    Assignee: Suntech, Inc.
    Inventor: Richard D. Stegall
  • Patent number: 4005666
    Abstract: There is described a comminuting type ice cutter for use with vessels operating in ice-covered waters. Fluid, such as water or air, is injected into the region of each cutter edge to break the partial vacuum which is created at the cleavage interface of the ice fragments as they are broken away from the body of ice by the cutting or wedging action of the cutters. The fluid is introduced by passages extending through the cutter blades and opening adjacent the cutter edges. Alternatively the fluid may be forced into the cutting region by separate jets which may be either stationary or may rotate with the blades.
    Type: Grant
    Filed: June 23, 1975
    Date of Patent: February 1, 1977
    Assignee: Sea-Log Corporation
    Inventor: Joseph F. Schirtzinger
  • Patent number: 3973509
    Abstract: An icebreaker having a cantilever forecastle from which is suspended one sliding carriage or a plurality of sliding carriages. Each sliding carriage mounts one planing tool or a plurality of planing tools with increasing depth of cut, in a tandem arrangement. The suspension means for each sliding carriage may consist of a linkage or of cables or booms. The one or several sliding carriages are yieldingly suspended and may be withdrawn into the ship's hull. The ice cutting operation may be assisted by vibrating the sliding carriage or supplying heat and/or pressurized water to the planing tools.
    Type: Grant
    Filed: July 15, 1974
    Date of Patent: August 10, 1976
    Inventor: Heinrich Waas
  • Patent number: 3965835
    Abstract: A buoyant, cylindrical metal drum, having a plurality of elongate teeth protruding outwardly from the periphery thereof is mounted for rotation about its longitudinal axis in a generally U-shaped framework. The frame is pivotally attached to the front of a tug vessel and the drum may be steered, with respect to the boat, by moving the mounting frame about the pivot point. An internal power source and an eccentric counterweight, which may include a fuel storage container for the power source, are stationarily mounted within the drum which is rotated about the counterweight as an inertial reference. When the drum is rotated by its internal power source and moved against the water/ice interface of a floating arctic ice sheet, the moving teeth on the drum cut the ice and clear a path for movement of the drum and the tug boat through the ice covered water.
    Type: Grant
    Filed: March 28, 1974
    Date of Patent: June 29, 1976
    Assignee: Sun Oil Company
    Inventor: John D. Bennett