Patents Assigned to North Shore Partners
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Patent number: 7597060Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. The apparatus creates a reduced pressure region by diverting a first portion of the flow away from the surface of the hull. An air pocket is formed in the reduced pressure region and a second portion of the flow is directed through the air pocket by nozzles, which acts as a plunging jet and entrains air into the boundary layer.Type: GrantFiled: August 14, 2007Date of Patent: October 6, 2009Assignee: North Shore PartnersInventors: Donald P. Stubblefield, Jerry D. Stubblefield
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Publication number: 20080022914Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. The apparatus creates a reduced pressure region by diverting a first portion of the flow away from the surface of the hull. An air pocket is formed in the reduced pressure region and a second portion of the flow is directed through the air pocket by nozzles, which acts as a plunging jet and entrains air into the boundary layer.Type: ApplicationFiled: August 14, 2007Publication date: January 31, 2008Applicant: North Shore PartnersInventors: Donald Stubblefield, Jerry Stubblefield
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Patent number: 7267067Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. The apparatus creates a reduced pressure region by diverting a first portion of the flow away from the surface of the hull. An air pocket is formed in the reduced pressure region and a second portion of the flow is directed through the air pocket by nozzles, which acts as a plunging jet and entrains air into the boundary layer.Type: GrantFiled: January 19, 2005Date of Patent: September 11, 2007Assignee: North Shore PartnersInventors: Donald P. Stubblefield, Jerry D. Stubblefield
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Patent number: 7219614Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. A hemispherical protrusion creates flow separation by diverting a portion of the water flow away from the surface of the hull, which results in a reduced pressure region downstream from the protrusion. A vent located on the protrusion allow air to flow into the reduced pressure region. The air in the reduced pressure region is entrained into the water due to turbulent mixing from vortices shed on to the rear of the protrusion.Type: GrantFiled: April 15, 2005Date of Patent: May 22, 2007Assignee: North Shore PartnersInventors: Donald P. Stubblefield, Jerry D. Stubblefield
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Publication number: 20060231004Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. A hemispherical protrusion creates flow separation by diverting a portion of the water flow away from the surface of the hull, which results in a reduced pressure region downstream from the protrusion. A vent located on the protrusion allow air to flow into the reduced pressure region. The air in the reduced pressure region is entrained into the water due to turbulent mixing from vortices shed on to the rear of the protrusion.Type: ApplicationFiled: April 15, 2005Publication date: October 19, 2006Applicant: NORTH SHORE PARTNERSInventors: Donald Stubblefield, Jerry Stubblefield
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Publication number: 20060156965Abstract: An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. The apparatus creates a reduced pressure region by diverting a first portion of the flow away from the surface of the hull. An air pocket is formed in the reduced pressure region and a second portion of the flow is directed through the air pocket by nozzles, which acts as a plunging jet and entrains air into the boundary layer.Type: ApplicationFiled: January 19, 2005Publication date: July 20, 2006Applicant: NORTH SHORE PARTNERSInventors: Donald Stubblefield, Jerry Stubblefield
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Patent number: 6394483Abstract: A snowboard whose base is relatively thick in the mounting zones beneath each of the rider's feet and relatively thin between the two mounting zones. Thus, with normal loading applied through the rider's feet to the snowboard, the board will bow into a reasonably good approximation of an arc having a constant radius. Consequently, the portions of the snowboard coming in contact with the surface of the snow will substantially lie on segments of a circular arc, and the back half of the snowboard will substantially follow in the track of the front half of the snowboard. This is achieved by controlling the flexural rigidity in the mounting zones and in the center section between the mounting zones. The curvature of the snowboard in response to the application of forces by its rider is a function of the Area Moment of Inertia (I) of the transverse cross-sectional areas along the snowboard's length. In turn, the Area Moment of Inertia is a function of the geometry of the transverse cross-section.Type: GrantFiled: November 19, 1997Date of Patent: May 28, 2002Assignee: North Shore PartnersInventor: Donald P. Stubblefield
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Patent number: 6382658Abstract: A method of making a snowboard or ski so that the bottom surface of the snowboard or ski is capable of bowing into a desired longitudinal curvature, with a circular arc being the preferred shape, in order to enable a “perfect” turn to be carved. The method comprises the steps of selecting a desired longitudinal curvature of the snowboard during turns, determining the desired curvature of the snowboard at a plurality of cross-sectional portions thereof in order to achieve the desired curvature, and selecting the cross-sectional area moments of inertia at each of the plurality of cross-sections to provide the desired curvature. The thickness of the core of the snowboard is the preferred design variable. The center section of a snowboard designed in accordance with this method has smaller average area moment of inertia than one or both of the front and rear mounting zones.Type: GrantFiled: February 20, 1999Date of Patent: May 7, 2002Assignee: North Shore PartnersInventor: Donald P. Stubblefield
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Patent number: 5823562Abstract: A snowboard is disclosed having two cambers centered, respectively, below each of the two boot mounting zones.Type: GrantFiled: August 27, 1997Date of Patent: October 20, 1998Assignee: North Shore PartnersInventor: Donald P. Stubblefield
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Patent number: D338549Type: GrantFiled: July 9, 1991Date of Patent: August 24, 1993Assignee: North Shore PartnersInventor: Jerry D. Stubblefield