US1749017A - Speed boat - Google Patents

Description

March 4, 1930.` H. L. BRowNBAcK 1,749,017

SPEED BOAT l Enea sept. 18. 1925 Patented Mar. 4, 1930 UNITED, STATES PATENT vOFFICE: I

HENRY LOWE BROWNBACK,-OF NORRISTOWN, PENNSYLVANIA, ASSIGNOR TO BROWN- BACK MOTOR LABORATORIES, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW 'YORK SPEED BOAT Application led September 18, 1925. Serial No. 57,135.

. surface of said hull instead of being simply fair comprising an aerodynamic plane formed substantially to an aerofoil curve eX- tending from bow to stern. Thus, in speeding up, the hull will have the support of the i hydrodynamic plane or series of planes on the bottom surface which have comparatively high lift at low speeds and high resistance at high speeds, and as soon as the boat attains suflicient speed, the hull will be supported for the most part by the lift of the aerodynamic top surface caused by the rarification of the air above said surface, Just enough of the bottom surface touching the water to provide proper balance.

I will explain the invention with reference to the accompanying drawing which illustrates several practical embodiments thereof to enable others familiar with the art to adopt and use the same, and will summarize in the claims the essentials of the invention, the novel features of construction, and novel combinations of parts, for which protection is desired.

In said drawings Fig. 1 is a side elevation of a speed boat of the water-drive type, embodying my invention.

Fig. 2 is a top plan view thereof.

' Fig. 3 is a section on the line 3-3, Fig. 2.

Fig. 4 is a side elevation of a speed boat of the air-drive type embodying my invention. Fig. 5 is a top plan view of the boat shown in Fig. 4.

As shown, the boat is preferably substantially rectangular in plan, the width thereof being relatively great compared with its length. The bottom surface of the boat is preferably a hydrodynamic plane or series of planes, and as shown the bottom surface is preferably stepped as at la, the forward deeper portion 1b of the hull being curved upwardly at the bow, as at 1". The rear portion 1l of the bottom surface is shallower than the front portion 1", and the rear end of the bottom surface 1d is preferably stepped as atv 1, the portion 1t of the bottom in rear of the stepped portion 1 sloping upwardly and rearwardly to meet the top 2 of the hull.

The bottom surface is designed to support the weight of the boat by hydrodynamic reaction, the hydrodynamic planes 1b, 1d, having comparatively high lift at low speeds and high resistance at high speeds. The bottom of the hull however may be of any other type which will assist the hull in gliding over the surface of the water.

The top surface 2 of the'boat is preferably rectangular in plan, and instead of be'- ing simply fair is built to aerodynamic form, that is, a section taken through the hull from bow to stern, will give a top line having a true aerofoil curve, whereby as lthe boat attains suflicient speed the hull will be supported for the most part by the lift of the 'aerodynamic top surface 2, inst enough of the lower surface touching the water to provide balance, about 90-95% of thetotal lift of the hull being caused by the rarification of air above the top surface 2.

The front end of the top surface 2 is preferably rounded, as at 2, to meet the upwardly curved portion 1c of the bottom surface. As diagrammatically shown in Fig. 3, the hull ofthe boat is preferably built on a system of trusses 3 similar to an aeroplane wing, and cock-pits 2b may be provided in the top surface 2, but should be made as small as possible 'so as to maintain a maximum areaJ to the -top surface 2.

In Fig. 1, the hull is shown as being of water-driven type and houses an engine or motor 4, gear shift 4a, and the propeller shaft The hull construction of the air-drive type, shown in Figs. 4 and 5, is substantiall identical with the construction shown in igs. 1 to 3 inclusive, except that the pivot iin 7 is 5 placed at the rear end of the section l" of t e bottom surface, and the rudder 8 is located at the rear end of the hull, and controlled by the steering wheel 8a (Fig. 5). Furthermore the engine or motor 9 is placed upon t rear 10 end of the top surface 2 with the propeller 9 well above the surface of the water.

The air and water drive types of hulls however operate in substantially the same manner. At low speeds, with low resistances,

suiicient under surface is provided to react against the water and start the boat gliding and to set the aerodynamic top surface Q'at the best angle to exert lift on the hull causin the hull to gather speed with a minimum o drag. As soon as the top surface 2 exerts lift on the hull a change in the position of the center of lift of the hull will take place, which will set the angle of incidence of the aerodynamic top surface 2 to give the maximum of lift with the minimum of drift, and so place the bottom surface that it will exert but little actual lift but will glide with little resistance and act as a pressure shifter and balancer. r

Without the aerodynamic top surface 2 in an hydrodynamically supported hull, of usual type, the bottom surface would exert the entire lift, but with my thick section aerofoil top surface, the top surface will exert from 90-95% of the total lift, my boat therefore utilizing the best of both reactions, resulting in a great saving in power, or an increase in speed with the same power, since the water surface has a lift-drag ratio of from 4-1 to 7-1, and the aerodynamic surface has a lift drag ratio of about 18-1.

I d0 not limit my invention to the exact forms shown in the drawing, for obviously changes may be made therein within the scope of the claim.

/ I claim:

A water borne craft comprising a hull of truss construction, substantially rectangular in plan, having an aerodynamic upper sur face conforming substantially with an aero- "foil curve extending the entire length of the hull from bow to stern, and having a stepped hydrodynamic bottom surface of corresponding length; said hull having a relatively small cock-pit set therein flush with the upper surface; and means associated with the hull for propelling the same.

In testimony that I claim the foregoing as my own, I aiiix my signature.

a HENRY LOWE BROWNBACK.

Images