US 2381622 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Aug.' 7, 19.45- c. c. sHEr-PARD BOAT v 3 Sheets-Sheet 1 Original Filed Sept. 19, 1941 Augf?, 1945. c. c. sHEPPARD 2,381,622
'Y BOAT original Filed Sept. 19, 1941 s sheets-sheet 2 .l By c'. c'. .swig/Afa Aug# 7 1945 c. c. SHEPPARD 2,38L5622 BOAT Original Filed Sept. 19, 1941 3 Sheets-Sheet 3 ,y
c. a s//fPPA /w www Patented ug. 7, 1945 i i UNITEDJSTATES PATENT oFF-'ICE Creedy Sheppard, Fort Lee, N. J.
substituted for yabandoned` application Serial No.`
411,578, September 19, 1941. `This application v p October 17, 1944, Serial No."559,026
6 Claims. (Cl. 1154-37) This application is a substitute for application Ser. No. 411,578, iiled September 19, 1941, for Boats, and the invention relates more particularly to thattype including speed boats and sea sleds, it being one object ofthe invention to provide a `boat of such construction that high speed or propulsion is obtained. While it has been stated that .the improved construction is particularly adapted for speed boats and sea sleds, it is to be understood that it is not limited to thisI particular type of boat. f
Another object ol` the invention is to provide a boat having its hull so constructed that it includes runners` extending longitudinally thereof at opposite sides oi its bottom and constituting streamlined shields for propellers housed therein and having portions protruding downwardly through openings formed intermediate the length of the runners. .l
Another object of the invention is to provide a lboat wherein `an air pocket is formed under the bottomof the boat between the runners to reduce friction between the water and bottom of the boat and thus aid in increasing the speed of theboat. l i
Another object of the invention is to provide the bottom of the boat with cross bars or strips extending transversely thereof between front and rear ends of the yrunners and constituting iront and rear walls of the air pocket, the strips being of appreciably less depth than the runners and so formed in cross section that the `boat may moverapidly through the water and air pass out from the pocket at the stern ofA the boat as it moves forwardly.
Another object of the invention'is to provide a boat wherein engine exhaust is discharged into an air pocket under the hull for effecting increased buoyancy and, 1n the case-of airplane pontoons, to increase the buoyancy and turbulence and decrease surface tensionV on take-off.
Another object of the invention is to so construct the boat` that as its speed is increased, air and exhaustgases moving rearwardly in the air pocket will have a tendency to shift the boat upwardly and thus reduce its draft and, consequently, reduce frictional drag of the water upon the bottom of the boat.
Another object-l of the invention is to provide the boat with runners so formed that they taper y rearwardly and thus impart a streamlined effect to the runners and also cause the pocket to gradually increase in width toward its rear end.`
mize frictional thrust and turbulence as the boat is driven through the water and thus permit the boat to be propelled forwardly at increasedspeed with an engine of predetermined horsepower.y
Another object of the invention is to produce Another object of the invention is to minir a boat simple in construction, neat and attractive in appearance, and very sturdy.
In the accompanying drawings: 1
Fig. l is a top plan view of a boat of the improved construction.
Fig. 2 is a view showing the boat in side elevation with one of the pontoons or runners shown in longitudinal section.
Fig. 3 is a view looking at the bottom of the boat.
Fig. 4 is a sectional View taken longitudinally through the boat, on the line 4-4 of Fig. 1.
Fig. 5 is'a sectional view taken transversely through the boat on the line 5-5 of Fig. 2.
Fig.` 6 is a `fragmentary sectional view taken transversely through the bottom of the boaty on the lineV 6-6 of Fig. 2.
Fig. 'l is a transverse sectional view showing the normal draft of the boat. Fig. 8 is a similar view showing the draft of the boat when in motion.
The boat l may be of any length and beam desired and has a bottom 2 which is at for the full width of the hull and also flat for approximately its entire length, the portion 3 of the bottom being curved upwardly so that, as the boat is propelled forwardly, water will flow easilylunder the bow thereof. Pontoons or runners 4 extend longitudinally of the boat along opposite sides of the bottom 2 and, from an inspection of Figs. 3 and 4, it will be seen that these pontoons or runners taper transversely toward their rear ends and also decrease in depth rearwardly. The runners are V-shaped in .cross section, as shown in Figs. 5 through 8, and are hollow, each being closed at its ends and having its forward portion 5 curved upwardly and gradually reduced in width and depth to a point at its front end. By so forming the runners they will 4readily cut through the water as the boat is driven forwardly, and the curvature of the forward portion 3 of the bottom 2 and front end portions of the runners will impart a lift to the bow of the boat as it moves orwardly. Cross bars Band 'l extend across the under face of the bottom of the boat between front and rear end portions of the runners 4 and constitute end walls of a pocket 8 which extends along the bottom of the boat and gradually increases `in width ltoward its rear end. The cross bars or iront and rear walls are lsubstantially V-shaped in cross section, as shown in Fig. 4, and from an inspection of this figure, it will `be seen that when the boat is in motion, water and air may easily flow across these -end walls. It will also be noted that since the pocket has end walls, air will beltrapped inthe pocket and air held therein` when the boat slows down and is brought to a stop. The front wall B is deeper than the rear wall 1.
To force the boat through the water, there shown as helical blades formed solid with their shafts, it is to be understood that they may be in the form of helical strips welded at their ends'` to the shafts, or merely helical strips having stub shafts at their ends.
edges of the runners and the propellers project y,ed between the rearwardly extending forks 22 of rudder posts 23. The rudder posts extend vertically and are rotatably mounted through sleeves i `2II As ecuredsto'and rising from the bottom 2 of The shafts ID are spaced upwardly a very short distance from the lower f I downwardly through the openings I2 and out` wardly from opposite sides of the runners, as shown in Fig. 6, so that as the propellers are turned, their blades act upon the water to drive the boat forwardly or rearwardly, according to the direction in which the propellers are rotated. Universal joints I3 connect forward ends of the propeller shafts with transmission shafts yIll which extend forwardly at an upward incline and through the bottom of the boat, their front ends being connected to shafts of engines I5 by universal joints I6.
The specific type of engines used is optional, according to the construction of the boat. They maybe of the conventional fluid drive automobile type with crank shafts located in the pontoons and connected directly to the propellers, but in the illustration they have been shown located well forward of the boat and their exhaust pipes I'I extend rearwardly and terminate in enlarged mouths I8 secured about openings I9 formed in the bottom of the boat. The exhaust pipes may have communication with air pocket 8 through the bottom of the hull, as shown, through sides of the pontoons, or in any desired manner. Air and exhaust gases passing from the engines and discharged into the air pocket 8 ow toward the stern of the boat and escape from the pocket across the rear wall I thereof. Movement of air and exhaust gases through the air pocket towardk the stern of the boat imparts a forward thrust to the boat and serves t0 in-y crease forward speed of the boat as well as assuring a supply of air and exhaust gases in the pocket. The pocket is thus filled with air and exhaust gases and this eliminates direct contact of the bottom of the boat and upper portions of side walls 0f the runners with the water. Therefore, frictional resistance is decreased and the boat will be driven forwardly at high speed. As the speed of the boat increases, uplift is imparted to the boat and the draft is decreased from the normal draft level shown in Fig. 7, to that of Fig. 8, and, referring to-Fig. 8, it will be seen that the only portion of the boat immersed in water are the lower portions of the runners. As the curved under surface 3 of the bow of the b oat moves forwardly, a certain amount of air moves rearwardly across the front cross bar or wall `6 into the pocket 8, but the curved front face of this wall directs the water downwardly and imparts an uplift to the bow of the boat. The upwardly curved forward portions 5 of the runners also have a tendency to impart uplift to the bow as the boat moves forwardly. Guards 2U, formed of bars or strips of strong metal, extend longitudinally of the runners under the openings I2 and the propellers 9, with their end portions curved upwardly and welded to the lower edge portions of the runners. These guards protect the propellers from damage by striking obstructions in the water and also permit the boat to the boat about yopenings formed therein, and upper ends of thev vposts protrude from the sleeves andfcarrytillers to which ends of the steering line 26 are attached. The steering line extendsalong sides of the boat and is Wound about a drum 2.1 of the steering wheel 28 so that when the wheel is turnedthe tillers will be moved and the rudders adjusted to steer the boat. The rod 29 causes the two rudders to be simultaneously adjusted. It will be understood that a single rudder may be 'used "insteadof double rudders, if desired. Since the rudders are rotatably supported between the forks of the posts, they may turn about their 'axles as the boat is driven through the water, thus reducing frictional resistance of the rudders.
While it has been stated that the improved construction is particularly adapted for speed boats, there is another eld for the invention in which the bottom air space is maintained continuously and used solely to decrease water drag and immersion of they boat. This field is typified by canal boats, ferries, landing barges, and the like, where heavy weights are to be carried, and also in instances where the water to be traveled is shallow. Itis evident that by substituting air for water as the buoyant medium, the frictional drag is greatly reduced, permitting greater speed with less power. Further, in many cases the twin screw propulsion permits ready steering and maneuvering. The very shallow draft permits use for landing and in waters where conventional propellers would be fouled.
In the case of canal boats, a. further advantage arises from the steady slip stream of the helical propellers creating less damage to banks and bottom than the'turbulence of screwA propellers which prevent their use in some Waters. It is evident that utilizing the entire area of the barge having only narrow runners at sides and streamlined cross members fore and aft, a great percentage ofthe weight is air-borne. Also, in still waters, the depth of the air pocket need not beigreat', only enough to house small propellers so that moving parts are 'further from the bottom.`
To minimize frictionalfresistance, the center lines cf thefpontoons are arranged parallel to the axisv of the boat and the sides made symmetrical to vthem so that there is a constant streamline motion towardA the rear of the boat.
I am aware'that certain forms of sleds have been made in which' a boat'i's cut in two longitudinally and the two sections' transposed, leav ing a fiat outside and a curved inner section. It will be noted, however, that my invention differs in that the sides of the pontoons are symmetrica] and the Vflow line of the water is par-y allel at all times to the axis of the boat. This form of structure lends itself readily to quantity production since the boat bottom is essentially flat 'with the runnersI attached'thereto.
To'secure more eflicient propulsion, I propose that the presentpropellers be of helical form and mounted to operate in the section of the runners. 'I'his applies thrust directly in the line of motion instead of at an angle as is required with a propeller shaft slanting downward as in the conventional form of boat.
A still further advantage of this propeller is that it is working at maximum efciency. Engineers recognize thatthe normal form of screw propeller is a compromise one and that only one section works at maximum efficiency. At this point, the pitch is proportioned to the speed of the boat and there is very little slip. However, at points outside this diameter, it will be moving at higher velocity and at less emciency while points inside this pitch will be moving too slow for good efciency.
By using a small diameter helical propeller, the thrust can be concentrated along a very narrow area operated at maximum efficiency and an additional thrust obtained by the additional blades. Further, the turbulent effect of the improper proportions is minimized. With such a propeller mounted in the streamlined runner, the tendency of the water is to flow smoothly along without turbulence.
The effect of the turbulence on ordinary speed boats can be seen by observing the wake of the boat where the water is disturbed and thrown in all directions. A larger part of the energy is consumed in tossing the water around rather than in propelling the boat forwardly. While the boat construction may be mounted on ordinary runners, I prefer the twin type propellers shown. These may be driven by two separate engines synchronized, or with one engine with a driving gear.
Another field f usefulness for the invention is in the construction of pontoons for airplanes. In this case, surface tension of still water greatly retards take-oil and provision of the air pocket will not only provide air buoyancy but the exhaust gases filling the pocket will break up the surface tension and enable the airplane to rise more easily and with less power.
Having thus described the invention, what is claimed is:
1. In a boat construction, a hull having pontoons extending along the under face of its bottom at opposite sides thereof and constituting buoyant runners, and cross bars extending across the bottom of the hull between front and rear end portions of the runners and constituting end walls for an air pocket having side walls formed by the runners, said runners being gradually reduced in width toward their rear ends whereby the top of the air pocket gradually increases in width toward its rear end, and the front cross bar being of greater depth than the rear cross bar.
2. In a boat construction, a hull having pontoons extending along the under face of the bottom thereof at opposite sides and constituting buoyant runners, and cross bars extending vacross the bottom of the hull between front and rear end portions of the runners and constituting end walls for an air pocket having side walls formed by the runners, said runners being substantially V-shaped in cross section and gradually reduced in width and depth toward their rear ends, and the front cross bar being of greater depth than the rear cross bar.
3. In a boat construction, a hull having ponl toons extending along the under face of the bottom thereof at opposite sides and constituting buoyant members, and cross bars extending across the bottom of the hull between front and rear end portions of the runners and constituting end walls for an air pocket having side walls formed by the runners, said runners being substantially V-shaped in cross section and gradually reduced in width and depth toward their rear ends for substantially their full length and each having an upwardly extending forward end portion tapered to a point at its front end, and the front cross bar being of greater depth than the rear cross bar.
4. In a boat structure, a hull, hollow runners extending along the bottom of the hull at opposite sides thereof, cross bars extending across the under face of the bottom between front and rear end portions of said runners and, together with the runners, forming an air pocket closed along its sides and ends, said runners being substantially V-shaped in cross section and each formed substantially midway the length of the hull with a longitudinally extending opening through its side walls and lower edge, helical propellers rotatably mounted in said runners and extending longitudinally of the openings with their lower portions protruding through the openings, port and starboard engines in the forward portion of the hull, transmission shafts extending rearwardly from the engines through the bottom of said hull and into the hollow runners and connected with front ends of the, propellers, and exhaust pipes for said engines extending rearwardly therefrom and through openings in the bottom of the hull for discharging exhaust gases into the forward portion of the air pocket in the direction of the rear end of the boat.
5. In a boat construction, a hull, hollow runners extending along the bottom of the hull at opposite sides thereof, cross bars extending across the under face of the bottom between front and rear end portions of said runners and constituting end walls of an air pocket having side Walls formed by the runners, said runners being substantially V-shaped in cross section and gradually reduced in width toward their rear ends and each formed substantially midway the length of the hull with a longitudinally extending opening through its side walls and lower edge, the front cross bar being of greater depth than the rear cross bar, helical propellers rotatably mounted in said runners and extending longitudinally of the openings, and transmission shafts extending through the bottom of the hull and into the hollow runners and connected with said propellers.
6. In a boat construction, a hull, hollow runners extending along the bottom of the hull at opposite sides thereof, cross bars extending across the under face of the bottom between front and rear end portions of said runners and constituting end Walls of an air pocket having side walls formed by the runners, said runners being substantially V-shaped in cross section and gradually reduced in width toward their rear ends, the front cross bar being of greater depth than the rear cross bar, and a power plant in the forward portion of said hull having exhaust means extending rearwardly therefrom for discharging exhaust gases into the forward portion of the air pocket in the direction of the rear end of the boat.
CREEDY Cf. SHEPPARD.