Boat steering device utilizing hydrodynamic servo

Abstract

A steering device which is particularly suitable for the automatic steering of a sailboat on a preselected heading relative to the apparent wind incorporates a hydrodynamic servo device. An oar member which forms the hydrodynamic servo is mounted in a support housing and positioned in the water behind the boat for both rotational and pendulous motion. Also mounted in the support housing and positioned in the water behind the boat for solely rotational motion is a rudder member which is coupled to the oar member to provide a rotational input thereto in response to steering control signals. These steering control signals may be provided by a dual axis wind vane which generates an output when the heading of a sailboat relative to the apparent wind changes. When the oar member is rotatably driven from its neutral position (i.e., the position where the sidewise hydrodynamic forces balance each other out), the water force pendulously drives this member substantially sidewise. This sidewise motion signal is converted to a rotational motion signal which is coupled to the rudder member to effect steering of the boat in accordance with the steering control signal (in the case of automatic steering, to maintain the desired heading). The rudder-oar member control linkage and wind vane (if used) are integrated with the housing to form a single compact portable unit that can be removably installed on the transom of a boat.