US 3148652 A
Description (OCR text may contain errors)
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United States Patent 3,148,652 PLANING TYPE SPEED BOAT HULL Henry Donald anazzi, 178 Sewett Parkway, Buffalo, NA. Filed Aug. 31, 1962, Ser. No. 220,688 10 Claims. (Cl. 114-665) My invention relates to boat hulls and more particularly to speed boat hulls of the type shown in my Patent 2,900,- 945 and in my copending application Serial No. 43,944 now Patent No. 3,051,115.
An object of the present invention is to provide this type of hull with bottom surfaces formed and arranged to cause the hull to bank toward the inside of a turn, thereby to improve its maneuverability, especially at higher speeds and thereby to reduce the tripping action and tendency such hulls have to overturn when tight turns are made at higher speeds.
Another object is to provide such a hull with bottom surfaces formed and arranged to cooperate during turns in generating a lift which cause it to readily bank to the inside of a turn, thereby reducing the normal tendency to trip and overturn on tight, highspeed turns.
Another object is to provide such a hull with an airdisplaced water tunnel having a central fore and aft tun nel-dividing member formed and arranged therein and extending from adjacent the bow rearwardly to the stern to divide the tunnel into spaced tunnel portions each serving to direct water passing therethrough away from the propeller of an outboard motor securable to the stern in the usual manner, thereby to avoid providing excessive cavitation in said water by the propeller.
FIGURE 1 is a side elevational view of a hull constructed in accordance with the principles of my present invention.
FIGURE 2 is a bottom plan view of the hull shown in FIGURE 1.
FIGURE 3 is an enlarged rear elevational view of the hull shown in FIGURE 1.
FIGURE 4 is an enlarged transverse sectional view taken on the line 44 of FIGURE 1.
FIGURE 5 is an enlarged transverse sectional view taken on the line 55 of FIGURE 1, and
FIGURE 6 is a fragmentary detail horizontal sectional view taken on the line 66 of FIGURE 1.
Referring now to the drawings wherein like reference numerals denote like parts in the several views, a hull constructed to attain the objects of my present invention is generally indicated by the numeral 10.
As in my copending application, Serial No. 43,944 (Patent No. 3,051,115), the hull 10 of a generally rectangular shape is formed with a bottom surface 11 extending between its side walls 12 and its bow 13 and stern 14 and is formed with a central fore and aft tunnel 15 extending between the bow 13 and the stern 14. As in said copending application, a spaced pair of bow stems 16 is provided, each being spaced inwardly from one side 12 of the hull, and each bow stem is alined with the longitudinal center of one of a pair of spaced planing surfaces 17 which are also spaced inwardly from the associated side wall 12.
The fore half of the top wall or roof of the tunnel 15, as indicated by broken lines in FIGURE 1, is formed with a longitudinal curvature. As in my copending application, the tunnel 15 has a progressively diminishing transverse width in its forward portion. The planing surfaces 17 each extend rearwardly from their juncture with one of the bow stems 16 to the stern 14 and are slightly inclined transversely outwardly and upwardly-from their juncture 18 with the adjacent outer sides of the tunnel 15.
' The outer'edges of the planing surfaces 17 adjoin out- "ice wardly and upwardly inclined non-trip surfaces 19. The latter extend from the stern 14 to points adjacent the bow end 13 and each adjoins the lower edge of one of the side walls 12 and the associated stem 16. The non-trip surfaces 19 contiguous to their junctures 20 with the associated side walls 12 are each formed with a portion 21 which extends outwardly and slightly downwardly from the main portion of the associated surface 19. The portions 21 serve to direct displaced water outwardly and downwardly and thereby act as spray deflecting surfaces.
Referring to FIGURES 1 and 2, it will be seen that the planing surfaces 17 form junctures 18 with the upright side walls 22 of the tunnel 15. Said walls 22 extend along the transversely flat rear portion 23 to the outwardly curved fore portion of the tunnel 15. There the walls 22 are terminated by transversely extending walls 22', but the sides of the tunnel 15 downwardly therefrom and are longitudinally curved outwardly as at 17, thereby to allow water and air to readily flow over the curved portion, the walls 22' and the surfaces 23 and thus preventing blocking the flow of water and air thru the tunnel 15 at high speeds.
As shown in FIGURES 3 and 4 the upright side walls 22 of the rear half of the tunnel 15 extend downwardly from the flat portions 23 thereof, preferably at an angle of the order of to join the planing surfaces 17 at the junctures 18. Midway between the planing surfaces 17, the tunnel 15 is formed with a wedge-shaped, combined displaced water dividing and planing member 24 which, as best seen in FIGURE 2, extends forwardly from the stern 14 to a point slightly forwardly of the transverse plane of the junctures of the stems 16 with the planing surfaces 17.
The member 24 is formed for the major portion of its length with a substantially blunted wedge cross section and extends longitudinally of the hull midway between the sides of the tunnel 15. The sides 25 of the member 24 are each inclined upwardly and outwardly from the outer edges of the relatively inclined bottom portions 26, and preferably meet in the flat roof portion 23 of the tunnel 15 at an angle of the order of 45 As the member 24 extends forwardly the angles of the relatively inclined bottom portions 26 are progressively diminished, as shown by FIGURES 4 and 5, so that adjacent its forward end the bottom er the member 24 is narrower and has a relatively sharp V-shape in cross section. Thus the cross-sectional open area of the tunnel 15 is further increased at its forward end and the flow of water into the tunnel is fa cilitated. At'the stem end of the member 24 the sides 25 are flared laterally slightly as'shown at 27, thus restricting to a certain extent flow through the tunnel 15 at the stern and guiding the water passing from the tunnel away from the stern end of the member 24 and the propeller of an outboard motor which may be mounted on the hull transom with the propeller aft of the member 24, there by minimizing cavitation.
As clearly shown in FIGURES 1-3 the bottom por tions 26 of the member 24 are forwardly and upwardly inclined from a plane approximatelyone inch (1") below the plane of the stern ends of the planing surfaces 17.
'(FIGURE 3) to a plane approximately one inch (1").
hull from a selected straight course or a curved turn path. Since each of the surfaces 17 is an outwardly and upwardly inclined plane and the non-trip surfaces 19 extend outwardly and upwardly therefrom it will be apparent that due to the inclined relation of the surfaces 17 and 19 to the member 24 each side of the stern end of the hull is provided with what is known as a dead rise. This permits the bull to be readily tilted about the member 24 as a fulcrum toward the inner side of a selected turn path without causing undue outward swinging movement of the stern end of tle hull from said path, and without causing the tripping or overturning tendency found in prior hulls not provided with the features of my present invention.
Thus formed and arranged, the wedge-shaped member 24 also serves to divide and direct water and air displaced into the tunnel by the bow stems 16 into separate, laterally spaced portions of the tunnel so that such displaced water, which is more or less deturbulated by the action of the tunnel portions 22, 22 and 23 and the member 24, is directed outwardly away from the path of the propeller of the motor which may be secured to the stern 14 in the usual manner. It will be obvious to those skilled in the art that by directing such water away from the path of the propeller said propeller will rotate with less cavitation and will therefore operate more efficiently.
Assuming that the hull is making a tight left hand turn and is tilted toward the inner left side of said turn, so that the mean water level is approximately that indicated by the broken line L in FIGURE 3, it will be seen that the inclinations of the outer or right hand non-trip surface 19 and the associated planing surface 17 will cooperatively act in lifting the then outer side of the hull to maintain the inclination of the hull. It will also be seen that the associated surfaces 22, 23 and at each side of the member 24 resist outward swinging of the stern end of the hull and allow it to closely follow the left selected turn path.
In other words, during a turn of the hull to the left, the upright left hand surface 22 of the tunnel 15 tends to force displaced water against its left hand surfaces 23, 25 and 26, and the right hand surfaces 25 and 26 force such water against the right hand upright surface 22, whereby said surfaces tend to maintain the stem end of the hull against outward swinging movement to the right from the selected left turn path.
It will be obvious that during a turn of the hull to the right corresponding but opposed action takes place whereby outward swinging of the stern end of the bull to the left of a selected turn path is resisted.
The shape, size, form, relation and proportion of the bottom surfaces of the hull to one another, especially those of the tunnel 15, the member 24, the planning surfaces 17, the non-trip surfaces 19, the upright surfaces 22, the flat surfaces 23 and the inclined surfaces 25 and 26 of the member 24 must closely approximate those shown and described, for the reasons that extensive experimentation reveals that even minor changes in the shape, relation, etc. of said bottom surfaces may adversely affect the desired result.
In order to attain a maximum top speed from a given amount of propulsive force my present hull, as in my prior hull, may have each of its planing surfaces 17 divided intermediate its ends by a downwardly offset portion providing a step between its front portion 28 and its rear portion 29 so that when the hull reaches a planing speed and altitude it planes on the portions 28 and 29 and as the speed increases, rides on decreasing rear portions of said portions, thereby reducing their wetted area and allowing, as described below, escape of air thru said steps.
As shown in FIGURE 4, between the front portions 28 of the planing surfaces 17 and the rear portions 29 of said surfaces there are provided intermediate step spaces 30 for the escape of air from the tunnel 15. The spaces 30 extend outwardly across and slightly below the planes of the surfaces 29 and below the junctures 18 and are each in communication with an inwardly projecting step 31 formed in the contiguous non-trip surface 19 and in a step 32 formed inwardly in the contiguous side wall 12. The spaces 30, 31 and 32 are contiguously extended from. the tunnel 15 and are extended above the normal water level of the sides 12 of the hull to atmosphere, whereby a flow of air through the tunnel induces a predetermined flow of air through the spaces30, 31 and 32 to atmosphere and thereby prevent the blocking of air across and through the spaces 30, 31 and 32.
A bull constructed in accordance with the principles illustrated and described above fully meets the objects of my present invention, however, it should be understood that the herein disclosed form of said invention is intended to exemplify its principles and that various modifications and rearrangements of its component surfaces may be made within the scope of the appended claims wherein I claim:
1. A speed boat hull of the planing type wherein the hull bottom is provided with a pair of how stems spaced inwardly from the sides of said hull and spaced laterally from each other and each of said bow stems has, adjoining and extending rearwardly therefrom, a planing surface which has a substantially flat portion, which comprises: an elongated wall extending upwardly from the inner edge of each of said planing surfaces, a central, longitudinally extending tunnel defined by said walls and the associated bow stems, and having as a roof the bottom of said hull, a tunnel-dividing and planing member projecting downwardly from the roof of said tunnel and extending longitudinally and centrally of said tunnel from the stern of said hull to a forward point adjacent the area wherein said how stems adjoin said planing surfaces, said member having sides that are inclined with respect to the roof of said tunnel and to the bottom of said member, said sides and said bottom of said member, at the forward end of said member, terminating in substantial- 1y a point, and said bottom of said member being forwardly and upwardly inclined from a plane surface at the stern of said hull lying below the lowest point of said planing surfaces, and said tunnel being free from projections thereinto other than said member and being substantially uniform in width from the stern forwardly for more than half its length.
2. A speed boat hull as set forth in claim 1 in which the side walls of said tunnel are substantially vertical.
3. A speed boat hull as set forth in claim 1 in which said planing surfaces are outwardly and upwardly inclined.
4. A speed boat hull as set forth in claim 1 in which, adjacent the stern end of said member, the sides only of said member are flared slightly outwardly thereby narrowing the portion of said tunnel on each side of said member.
5. A speed boat hull as set forth in claim 1 in which the roof of said tunnel is substantially fiat.
6. A speed boat hull as set forth in claim 2 in which said planing surfaces are outwardly and upwardly inclined.
7. A speed boat hull as set forth in claim 2 in which, adjacent the stern end of said member, the sides only of said member are flared slightly outwardly thereby narrowing the portion of said tunnel on each side of said member.
8. A speed boat hull as set forth in claim 2 in which the roof of said tunnel is substantially flat.
9. A speed boat hull as set forth in claim 5 in which, adjacent the stern end of said member, the sides'only of said member are flared slightly outwardly thereby narrowing the portion of said tunnel on each side of said mem' ber.
10. A speed boat hull as set forth in claim 6 in which. adjacent the stern end of said member, the sides only of 2,020,792 Maynard Nov. 12, 1935 6 Martin May 31, 1960 Mills Aug. 8, 1961 Canazzi Aug. 28, 1962 FOREIGN PATENTS Great Britain "of 1881