Cross jet rudder for watercraft
United States Patent [191 Lorenz Apr. 1, 1975 CROSS JET RUDDER FOR WATERCRAFT [75] Inventor: Otto Lorenz, Lubeck, Germany .[73] Assignee: Orenstein &amp; Koppel AG, Lubeck,  
 [30] Foreign Application Priority Data Aug. 19, 1972 Germany 2240842 [52] US. Cl. ..114/151,115/16 [51] Int. Cl B63h 25/46 [58] Field of Search 114/148, 151; 115/39, 16  
 [56] References Cited UNITED STATES PATENTS 985,187 2/1911 Lindgren 115/39 FOREIGN PATENTS OR APPLICATIONS 1,177,966 9/1964 Germany 114/151 650,590 3/1935 Germany 1 14/148 Primary ExaminerTrygve Ml. Blix Assistant Examiner-Jesus D. Sotelo Attorney, Agent, or Firm-Mc: Glew and Tuttle [57] ABSTRACT A watercraft comprises a hull having an outer surface below 1 water-1ine with an inwardly indented cross-chan&#39;nel extending from one side to the other of the hull. A propeller is rotatably mounted within the cross-chan&#39;nel and oriented to direct a flow through the channel from one side of the hull to the other. In addition a conduit which defines a pressure equalizing passage extends through the hull from the outer skin on one side thereof to the cross-channel and advantageously another pressure equalizing passage extends through the hull from the exterior on the opposite side to the cross-channel.  
 5 Claims, 2 Drawing Figures PMENTEM 1 ms FIG. I  
 FIGZ  
 BACKGROUND OF THE INVENTION 1. Field of the Invention This invetion relates in general to the construction of watercraft or vessels and, in particular, to a new and useful watercraft having a hull with a channel extending transversely across the underside thereof with a propeller therein arranged to direct a flow current from one side to the other and which also includes at least one pressure equalizing passage extending from the cross-channel to the outer skin.  
 2. Description of the Prior Art An arrangement of one or more pressure equalizing channels for cross jet steering gears in watercraft is known where the pressure equalizing channels are arranged in the immediate proximity of the jet inlet and the jet outlet of a cross steering gear leading from one board wall to the opposite board wall. Such arrangements are said to increase the efficiency of cross jet steering gears particularly with increasing traveling speed, since the local overpressure and underpressure fields which consume energy and reduce the steering action, are balanced by the pressure equalizing channels. The cross jet steering gear can also be used for maneuvering when the ship moves. In order to be able to use these pressure equalizing channels for forward and backward travel, two pressure equalizing chambers with remote controlled closing mechanisms can be provided of which the pressure equalizing system for the respective direction of travel is opened. In the known arrangement it is necessary to install a channel which traverses the entire ship width and which requires much space particularly in wide broad ships. In addition, it has been attempted to keep the velocity of flow in the pressure equalizing channel as low as possible in order to reduce corrosion. This requires relatively large cross sections. The additional space requirement produces an increase not only in the cost of the steering gear but it also reduces the carrying capacity of the craft or vessel.  
 SUMMARY OF THE INVENTION The present invention avoids the disadvantages of the prior art particularly by reducing the costs for the installation of cross jet rudders provided with pressure equalizing channels so that the carrying capacity of the ship is not impaired. In accordance with the invention the pressure equalizing channels are arranged between the outer skin of the ship and the steering water channel of the cross jet rudder. The invention has the advantage that the installation cost is substantially reduced and the requirements that the channels traverse the en tire hull are avoided. By reducing the length of the pressure equalizing channels, the danger of corrosion is also reduced. In addition, the carrying capacity of the ship is not impaired.  
  In an advantageous embodiment, the pressure equalizing channels terminate in the steering water channel in the range between the propeller and/or the propellent water nozzle and the side of the ship where it opens to the outer skin.  
  In accordance with another solution of the problem, the pressure equalizing channels are arranged between the outer skin and the ship bottom so that pressure equalization can take place. This embodiment has the same advantage as the other and it is particularly suitable for ships with a flat bottom.  
  Accordingly, it is an object of the invention to provide a watercraft which comprises a hull having an outer surface below water-line with a cross-channel with propeller means therein for propelling water through the channel and which includes a conduit defining a pressure equalizing passage through said hull extending from the outer skin of the hull to the cross-channel on the same side of the vessel.  
  A further object of the invention is to provide a cross jet rudder for watercraft which is simple in design, rugged in construction and economical to manufacture.  
  For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.  
 BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings:  
  FIG. 1 is a partial horizontal cross sectional view of a ship having a cross jet rudder constructed in accordance with the invention; and  
  FIG. 2 is a transverse sectional view of a hull of a ship of another embodiment of the invention.  
 GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in. particular, the invention embodied therein comprises a vessel or ship generally designated 10 in the embodiment of FIG. 1, which includes an outer skin or surface 1 ofa hull generally designated 12 with a steering water channel 2 defined through the hull. Water movement or propulsion means includes a rotatable propeller 3 oriented in the channel to move the water stream from one end to the other end of the channel and from side of the ship to the other. In this embodiment the channel is connected in accordance with the invention, with a pressure equalizing channel 4 and 4&#39; on respective sides of the vessel which extend from the outer skin 1 to the channel at a location between the water movement means and the associated side of the ship or end of the channel.  
  In the embodiment illustrated in FIG. 2 there is disclosed a vessel generally designated 10 which includes a cross-channel 2 defined across the ship bottom 6. In this embodiment pressure equalizing or steering water channels 5 and 5&#39; extend from the outer skin side surface 1 directly into the water channel 2.  
  While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.  
 What is claimed is:  
  l. A cross jet rudder for watercraft, comprising a watercraft hull having a steering water channel defined in said hull extending transversely from side to side below the water line thereof, a water pressure equalizing channel extending entirely below the water line and from the outer surface of said hull on one side of the watercraft directly adjacent the steering water channel and directly into the steering water channel at a spaced location from at least one end thereof and being normally filled with sea water, and propulsion means in said steering water channel for moving water through said steering water channel.  
  2. A cross jet rudder according to claim 1, wherein said water pressure equalizing channel is located on one side of said hull, and including an additional water pressure equalizing channel on the opposite side of said hull, extending from the exterior surface of said hull into said steering water channel at a spaced location from its opposite end.  
  3. A watercraft comprising a hull having an exterior surface, a cross water channel extending transversely through said hull, propulsion means in said cross water channel oriented between the ends thereof in a position to direct flow through said channel from one end to the other, said crosswater channel terminating in an opening on each side of said hull, and a water pressure equalizing conduit located entirely below water level and extending through said hull directly adjacent said cross water channel from the exterior surface thereof, intosaid crosswater channel, said water pressure equalizing conduit having an open sea water receiving end below water level at the end thereof extending through the surface of said hull.  
 4. A watercraft according to claim 3, wherein said tion from its associated end.