Trim tabs and surface drive propeller bite control
OwnerJames P. von Wolskeinventor
Life of this patent
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Abstract
A trim tab of resilient material affixed in a cantilever fashion at the stem of a boat and of a regressive flexural stiffness such that when deflected, the undersurface of the trim tab assumes the shape of a progressive curve in the direction of water flow. A trim tab of a progressive curve which has gas or liquid ejection to the undersurface to control the boundary layer. A trim tab located under a surface drive whereby the bite of the propeller is controlled relative to the trim tab and the trim tab is controlled to optimize the boat hull.
Claims85
An adjustable trim tab for attaching to the stern of a boat, comprising:
- a resilient plate having a forward end for mounting to the stem of the boat and a rearward end, the plate having a regressive flexural stiffness from the forward end to the rearward end;
- and
- a trim adjustment device, coupled to the rearward end of the plate and for coupling to the stem of the boat, that moves the rearward end of the plate;
- the plate having an operative bottom surface that is deflected in a progressive curve from the forward end to the rearward end of the plate under operating conditions and with force applied by the trim adjustment device.
A surface drive system for a boat, comprising:
- a surface drive propulsion system including a surfacing propeller affixed to a proreller shaft;
- and
- a hull extension having a forward end attached to the stern of the boat and a rearward end positioned under the propeller shaft and in front of the surfacing propeller to reduce variations in propeller blade immersion of the surfacing propeller.
A boat, comprising:
- a chassis including a stem surface;
- a resilient plate having a forward end and a rearward end, the forward end being mounted at the stem of the chassis, the plate having a generally regressive flexural stiffness from the forward end to the rearward end;
- and
- a trim adjustment device, coupled to the stem of the chassis and to the rearward end of the plate, that applies up and down force generally perpendicular to the rearward end of the plate.
A boat, comprising:
- a chassis including a stem;
- a surface drive propulsion system mounted to the chassis and including a surfacing propeller affixed to a propeller shaft;
- and
- a trim tab having a forward end and a rearward end, the forward end being mounted to the stem of the chassis, and the rearward end positioned under the propeller shaft and in front of the surfacing propeller to reduce variations in propeller blade immersion of the surfacing propeller.
Dependencies are inferred from the claim text.