# US 4,392,445 A · Flexible bow air ride boat hull > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,392,445 A - Document ID: US4392445A - Status: Granted - Kind: A - Application number: 06/269,908 - Filed: 1981-06-03 - Granted: 1983-07-12 - Earliest claimed: 1976-11-01 - Assignees: Paulette Renee Burg; Sheri Renee Burg; Daniel Earl Burg; Nicole Renee Burg - Inventors: Donald E. Burg - Web page: https://patentgrep.com/patent/US4392445A ## CPC - B63B 1/38: using air bubbles or air layers {gas filled volumes (waterborne vessels travelling on air cushions B60V3/06)} - B63B 2001/202: {divided by transverse steps} - Y02T 70/10: Measures concerning design or construction of watercraft hulls - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An improved performance marine surface vessel with at least one recess that intersects the hull substantially beneath the static waterline thereof, the recess bounded by stabilizing, load-carrying, catamaran-like side hulls, flexible seal member at its forward portion, with downwardly extending generally bow shaped members located at its aft portion and optionally therebetween, with the recess being supplied with pressurized gas to maintain a lift-augmenting, restrained pressurized gas layer under the hull that improves load carrying capability, efficiency and ride quality. The flexible or soft seal member at the front of the vessel absorbs much of the initial wave impact thereby contributing substantially to the exceptional ride quality which, along with efficiency and speed, is a major object of the invention. The aft bow members, and optional intermediate bow sections in some cases, may ride in the water like small bow sections thereby improving hull ride and handling characteristics and reducing gas leakage. In the preferred embodiment of the invention, the catamaran sidehull keels diverge thereby allowing a smaller width seal between the sidehulls forward with resultant smoother ride and less gas leakage forward. The bow shaped members along with the catamaran-like side hulls provide gas restraining means, sure tracking and turning characteristics when underway in any type of sea, and proper hull attitude and trim without wallowing at low speeds or yaw, roll or pitch instabilities at high speeds even if the pressurized gas supply is wholely or partially inoperative. ## Claims ### Claim 1 In an improved boat hull that is partially supported by a pressurized gas lifting surface including a recess in an underside of the hull, which recess is supplied with pressurized gas from at least one powered gas supply source through at least one gas inlet connected to said recess, and having a gas sealing forward flexible member which is supplied with gas from at least one gas inlet, the improvement comprising: stabilizing, load-carrying catamaran-like sidehulls beginning at a forward portion of and extending downward from the hull and having keels extending substantially parallel to each other rearwardly from said forward portion of said hull to a point at which they begin to diverge, said gas sealing forward flexible member extending between and substantially to said point of divergence of said substantially parallel portions of said side hull keels; and at least one fixed substantially rigid aft gas sealing bow member extending over a major portion of recess width, said bow member including at least one surface in part curvilinear and at least partially comprising at least one inverted V structure. ### Claim 2 (depends on 1) The hull of claim 1 wherein the catamaran side hull keels diverge by at least one hundred percent (100%) of the distance between them at their forward portions. ### Claim 3 (depends on 2) The hull of claim 2 which further comprises at least one additional bow member proximal to the recess. ### Claim 4 (depends on 1) The hull of claim 1 which further comprises at least one additional bow member proximal to the recess. ### Claim 5 (depends on 4) The hull of claim 4 which further comprises individual fluid communication of gas pressurizing means with individual portions of the recess. ### Claim 6 (depends on 4) The hull of claim 4 which further comprises at least one gas passageway in an underside of at least one of the additional bow members thereby allowing gas to flow between portions of the recess. ### Claim 7 (depends on 1) The hull of claim 1 wherein catamaran sidehull keel divergence is accomplished by at least one outward step in said side hull keel. ### Claim 8 (depends on 1) The hull of claim 1 wherein the gas sealing forward flexible member is pressurized from a pressurized gas source through a pressure regulating device. ### Claim 9 (depends on 1) The hull of claim 1 which further comprises at least one gas sealing forward flexible member that can be detached while the hull is waterborne. ### Claim 10 (depends on 1) The hull of claim 1 wherein the side hulls have non-trip chines. ### Claim 11 In an improved boat hull that is partially supported by a pressurized gas lifting surface including a recess in an underside of the hull, which recess is supplied with pressurized gas from at least one powered gas supply source through at least one gas inlet connected to said recess, and having a gas sealing forward flexible member which is supplied with gas from at least one gas inlet, the improvement comprising: stabilizing, load-carrying, catamaran-like sidehulls beginning at a forward portion of and extending downward from the hull and having keels extending substantially parallel to each other rearwardly from said forward portion of said hull to a point at which they begin to diverge, said gas sealing forward flexible member extending between and substantially to said point of divergence of said substantially parallel portions of said side hull keels; and at least one fixed substantially rigid aft gas sealing bow member extending over a major portion of recess width, said bow member including at least one surface in part curvilinear and at least partially comprising at least one V structure. ### Claim 12 (depends on 11) The hull of claim 11 wherein the catamaran side hull keels diverge by at least one hundred percent (100%) of the distance between them at their forward portions. ### Claim 13 (depends on 12) The hull of claim 12 which further comprises at least one additional bow member proximal to the recess. ### Claim 14 (depends on 11) The hull of claim 11 which further comprises at least one additional bow member proximal to the recess. ### Claim 15 (depends on 14) The hull of claim 14 which further comprises individual fluid communication of gas pressurizing means with individual portions of the recess. ### Claim 16 (depends on 14) The hull of claim 14 which further comprises at least one gas passageway in an underside of at least one of the additional bow members thereby allowing gas to flow between portions of the recess. ### Claim 17 (depends on 11) The hull of claim 11 wherein catamaran sidehull keel divergence is accomplished by at least one outward step in said side hull keel. ### Claim 18 (depends on 11) The hull of claim 11 wherein the gas sealing forward flexible member is pressurized from a pressurized gas source through a pressure regulating device. ### Claim 19 (depends on 14) The hull of claim 14 which further comprises at least one gas sealing forward flexible member that can be detached while the hull is waterborne. ### Claim 20 (depends on 11) The hull of claim 11 wherein the side hulls have non-trip chines.