US1670622A - Boat - Google Patents

Description

AMay 2211928. l 1,670,622

w. A.l HICKMAN BOAT l Filed Jan. l0`, 1923' Y 2 Sheets-Sheet 2 Patented May 22, 1928.

BOAT.

' Application filed January 10, 1923. Serial No. 611,885.

This invention pertains to improvements in boats. It is among the objects of the invention to provide a boat having a single propeller with its hub near or above the surface of the water and in which the moment of force tending to move the boat laterally is minimized. The invention is particularly useful in connection with boats of the gliding or semi-gliding type.

In the drawings which show a preferred embodiment of one form of my invention Fig. 1 is a plan of a boat;

Fig. 2 is a side elevation thereof;

Fig. 3 is a central vertical section on the line 3 3 of Fig. 1, being partly in elevation;

Fig. 4 shows the stern of the boat, a propeller and steering system on a scale larger than in Fig. 1;

Fig. 5 is an elevation showing the stern of a boat and its propulsion system. The

rudders and rudder controls are in a modified form; l

Fig. 6 is a section on the line 6 6 of Fig. 5, bein partly in elevation; and

Fig. is a view similar to Fig. 6, showing Ehe action of the rudders when turning the oat.

Boat propulsion systems of the type wherein the propeller or propellers are only partially submerged are commercially known as surface propulsion systems. Such systems have beenhighly developed where a plurality of propellers have been used, acting in opposite directions to neutralize the side thrust on the boat. Thus twin surface propellers turning in opposite directions have been very successful while four surface propellers have also been highly successful on larger boat/s.

Various attempts have been made to develop surface propulsion systems having but a single propeller. It .was very early attempted to operate relatively deep draft vessels such ascanal boats by means of surface propellers operated in pairs or even by single surface propellers. Such boats, however, did not provide a regulated dipfor the propellers.

' Attempts have been made/'to neutralize the side thrust in various ways as by angling the propeller shaft relative to the longitudinal axis of the boat and to provide either a sinvgle propeller or plural propellers .onthe 65 same shaft presenting oppositely inclined surfaces. Surface propulsion has been commercially adapted to a considerable extent on boats of the type which present from beneath their stern a relatively fiat sheet of water in which the propeller blades dip to an extent regulated by the distance of the shaft from the adjacent bottom of the boat and by the inertia of the water when the boat is in motion. In my earlier United States Patent No. 1,044,176, issued Nov. 12, 1912, I have shown both twin and single surface propellers but the efficiency of the single surface propeller illustrated was relatively low because of the turning moment exerted on the boat by reason of the tendency of the single surface propeller to paddle the stern of the boat toward the side at which the propeller blades enter the water with resultant tendency of the boat to turn in the opposite direction. To counteract this turning moment, it was necessary to utilize the rudders to a very great extent in order to hold the boat on a straight course with a resultant drag which made these boats much less eicient than those having plural balanced propellers.

I have found that the tendency of the surface propeller to steer the boat may be to a large extent reduced, and at some speeds, practically eliminated -by providing adjacent the dipping portions of the propeller one or more counteracting surfaces normally in one or mre planes cutting the water in directions generally parallel with the longitudinal axis of the boat. In thepresent application I` have shown the particularly eective combination of tw'o counteracting surfaces, one on each side of the propeller and preferably extending as shown, to. a depth approximating that of greatest dip of the propeller blades, while extending a considerable distance rear of the propeller toA be acted on by the water delivered out-. wardly and rearwardly by the propeller. In the preferred embodiment of my inven` tion herein shown, these counteracting surfaces are utilized as rudders to steer the boat, but exercise considerable force, tending to keep the boat on a straight ,course and to neutralize the side thrust of the -propeller even when the rudders are in planes parallel with the axis of the boat and exercising no steeringfunction as ordinarily considered. In my application Serial No. 611,886 filed herewith, I have shown the fixed plates, incapable of being turned or swun as rudders, yet performing their functions to counteract or minimize the steering action of the propeller. The claims of the present application are eneric to dominate such counter-acting sur aces generally while the claims of my co'pending applications, Serial Nos 611,886 and 611,887 filed herewith are more specific.

Referring to the drawings and the preferred form of my invention selected for illustrative purposes. I have shown a hull of the inverted V-bottom type, generally' like that illustrated in detail 1n my co-pending application Serial No. 604,596, filed'Dcc. 2, 1922, the bottom of the boat representing, as indicated by Fig. 2, a series of inverted V sections gradually broadening out toward the stern and terminating in a straight transom, as shown by Figs. 3 and 5. This hull is ofthe planingtype. lMy invention is, however, useful in connection with hulls of the semi-planing type or even of the displacement type, so long as the stern of the boat is so shaped as to deliver to the propeller a sheet of water providing a regulated or substantially regulated dip for the propeller.I Thus in the hull illustrated the bottom of the boat adjacent the stern 10 will deliver a sheet of water as illustrated at 11, passing slightly below the hub 12 of the propeller (which projects from the stern transom) and regulating the dip of' the blades 12 thereof, as best shown in Figure 3. Assuming the propeller turns in counterclockwise direction as viewed in Figure 5, it will exert a moment of force normally tending to move the stern of the boat to port, without any corresponding tendency similarly to move the bow of the boat. Thus the boat will constantly tend to turn to starboard unless counteracted by rudders or other means. Where counteraetingof this tendency is effected by steering action of rudders as ordinarily placed, considerable power is lost in dragging through the water 'the rudder or lrudders which to maintain a straight course must present a considerable surface opposing forward movement of the boat. In some instances it is practicable somewhat to counteract this tendency of the propeller to steer the boat, by locating the axis of the propeller at one sideV of the longitudinal axis of the boat as is illustrated in Fig. 5 where the propeller revolves in connterclockwise direction as viewed from stern. The location of the propeller axis to lStarboard of the longitudinal center line of the boat tends to turn the boat to port, counteracting to some extent the tendency of the propeller to steer the boat to star-.

board, and this without loss of power as where rudders are used to exert the counteracting force. y In .ordinary boat construction it is not desirable sueiently to move the engine out of center of the boat entirely to counteract the steering action of the .propeller, and this is particularly true in boats of the inverted V-bottom type in which any tendency to list the boat to starboard or port exerts some steering force in a corresponding direction by reason of the increased length of outwardly curving surface presented to the water by the bottom of the boat on that side which is lower in the water. When, therefore, the engine is located out of center of the boat I prefer that it be not sufficient but that the trim of the boat may be maintained by locating on the opposite side of the boat the oil tanks, batteries and other supplemental equipment.

Whatever contributory forces be utilized to assist in counteracting the steering" tendency of the single surface propeller, I greatly prefer to utilize and primarily to depend upon submerged surfaces closely adjacent to the propeller. In the preferred embodiment of my invention illustrated, these surfaces are provided by the rudders 13--13 pivoted at 111-14 substantially in line with and preferably slightly aft of the transverse plane of the propeller and providing the greater portion of their area rearwardly. of the propeller blades while providing a relatively restricted forwardly extending area 15 to oppose the passage ,of any A considerable amount of water from the propeller blades forwardly of the rudder pivots.

I have found that by arranging counteracting surfaces in thegeneral relationship of the rudders heretofore described, the `propeller, turning in counterclookwise direction as viewed from vthe stern, reduces the pressure of water on the inside of the rudder 13A as viewed in Fig. 5, whileincreasing the etV pressure of the water against the inside surface of the rudder 13B. Thus the water on the outside of the rudder 13A overbalances the lessened pressure ofthe water on the inside of the'rudder and provides a component of force pressing the rudder 13A and consequently the stern of the boat to starboard as viewed in Fig. 5, while at the Sametime pressure is built up on thev inside of the rudder 13B beyond thenormal pressure of the water, which pressure overcomes the pressureof the water on the outside of rudder 13B and also exerts a resultant force to starboard on the rudder and therefore on the stern 'of the boat. vThese combined pressures to starboard on the rudders 13A and 13"v obviate the necessity for steering action will to some extent obviate the drag attending the maintenance of the boat on a straight course by steering action alone. Where the propeller turns in clockwise direction the action of Similarly placed counteracting surfaces will tend to produce a resolution of forces urging the stern to port and counteracting the tendency of the propeller to movc the stern of the boat to starboard. I have found that where the lines of the boat, thel classes of boat and certain classes of workhas decided advantages over plural propel- 1ers in that it is not necessary .to provide plural engines or gear connections for single engines as in the case of plural propellers, in that the Weight; of the propeller and equipment may be kept down in proportion to the power and propeller area provided.

Referring to the propeller area of given pitch which it is desirable to provide for a single as compared with twin surface propellers, I have found that in some instances at least, the product of area times the average rate of movement through the Water of the blades of a single surface propeller may be somewhat less than the product of the area times the average rate of movement through' the water of the blades of an efficient pair of surface propellers adapted to be actuated by the same engine. As the rate of revolution is preferably constant for any given engine the above is availed of vby cutting down the area of the single surface propeller, decreasing its diameter and any or all normal proportions to decrease the friction losses. I have found that I may to advantage use a propeller of pitch ratio less than one to one, that is, the pitch is less than the diameter.

lWhere the counteracting surfaces adjacent the submerged portions ofthe single surface propeller are adapted to turn and be utilized as rudders, a particularly. eflicient steering control is provided for'some classes of boats because where it is desiredto turn the boat to starboard with a propeller turning in a counterclockwise direction the propeller assists the turning operation when the rudders are turned in the directions ordinarily necessary to produce the desired turning movement. When, on the other hand, it is desired to turn the-boat in the direction opposite to that which the lateral paddling action of the single surface prorudders by reason of the lower pressure on the inside of one rudder and the added pressure on the inside of the other rudder produced by the transverse How of water acted upon by the propeller. The same beneficial action with regard to steering the boat is presented where the propeller turns in clockwise direction, the effect on and function of the opposed counteracting surfaces being the same.

In races in the United States the turns are usually to port while in English races the turns are to starboard. I have found that where, as in the United States races, quick turns to port with much reduced throttle are desired, a left-hand or counterclockwise turning propeller as shown in Fig. 5 will materially assist in turning the boat, if the engine be slowed, because the propeller blades, turning relatively slowly as compared with the speed of the boat, act as rudders, their pitch providing the required angling relative to the direction of movement of the boat. This is particularly efficient with in- -verted V-bottom boats, as this propeller action contributes to the proper banking of the boat on the turn and brings into play the exceedingly eiiicient steering action aris-y ing from increasing the outwardly curving water-line of the inverted V -bottom toward the inside of the turn.

In addition to the advantages above mentioned arising from the use of the single surface propeller as compa-red with twin surface propellers actuated by a single motor, is the fact that the omission of the gearbox enables me to locate my engine and consequently my center of weights further aft .than where the gear box is utilized. This location ofthe center of weights further aft in a boat of the inverted V-bottom type is particularly advantageous ,because such boats enable the center of weights to be carried far aft eiiciently even at moderate speeds. IVhere, as I prefer. the hull presents an increasing angle of incidence afl- ]'acent thev stern, exerting greater lifting force at that point, the provision of this lifting force is particularly advantageous because permitting a markedly superior distribution of weights relative to supporting surface throughout the boat. Boats properly designed and embodying my invention are soft in action, do not pound in a sea,

are seaworth even in'a following sea and are comforta le, safe and eliicient, size and speed considered.

In that embodiment. of my invention shown in Figs. 1 to 4, the rudders are in vertical planes and are yactuated by bell cranks 20-21 presenting arms extending rearwardly over the rudders and connected by a link 22 and the other arms'of the bell cranks extending each outwardly toward the, adjacent side of the boat connected b suit? able cords or Wires to any preferre 'form of steering mechanism.

For boats of great speed, it is desirable oppositely to incline the planes of the rudders so that they yflare outwardly at the bottom and contribute to the banking of the boat in the proper direction during turning of the boat at speedl Thus with the rudder arrangement illustrated in Fig. 5, if the rudders 13A and l??B be swung to the right to turn the boat to starboardj the outer surface of the rudder 13B will undercut thel water and drag down the starboard side of the boat while the inner surface of the rudder 13A will meet the water at such an angle as to tend to elevate the port side of the boat, thus bankingvl the boat in proper direction for the turn to starboard. Similarly in turning to port, the outer surface of rudder 13A will tend to undercut water, dragging down the port side of the boat while the inner surface of the rudder 13B overcuttin the water (presenting a semi-planing surl ace) vill tend to raise the starboard side of the oat. f

While I have shown and described preferred embodiments of my invention, it is understood that I have done so for purposes of description and not for pur oses of limitation and that, while I have s own and de' scribed a preferred combination of lvarious improved features in a single boat and while such features are particularly useful in combination with each other, they are nevertheless of use independently of each other and that major changes involving omission, alteration, substitution and reversal of parts and even changes in the mode of voperation maybe made without departin from the scope of my invention, which 1s best de' lined in the following claims.

I claim- 1. A boat having a hull, a single propeller having a hub normally emersed when the boat is under way and a submer ed surface laterally adjacent the ropeller a body of Water in which the propeller turns, the reaction of such body of water on the submerged surface counteracting the tendency of the ropeller to steer the boat.

2. A boat aving a hull, a single propeller ut having substantial clearance t erefrom to provide having a lhub normally emersed when the boat is under way and a submerged surface laterally adjacent the propeller at that side thereof toward which the water is urged by said propeller but having lsubstantial clearance therefrom to provide a body of water in which the propeller turns, the reaction of such, body of water on the submerged surface counteracting the tendency of the propeller to steer the boat.

3. A boat having a hull, a single propellerv having a hub normally emersed when the boat is under way and a submerged surface laterally adjacent the propeller at that side thereof from which the water is urged by said propeller but having substantial clearance therefrom to provide a body' of water in which .the propeller turns, the reaction of such body of water on the submerged surface counteracting the tendencyof the propeller to steer the boat.

4. A boat having anhull, a single propeller having a hub normally emersed when the boat is under way and submerged surfaces laterally adjacent the propeller, one at each side thereof, 'but having substantial clearance therefrom to provide a body of water in which the propeller turns, the `reaction of such body of water on the submerged surfaces counteracting the tendency of the propeller to steer the boat.

5. A boat having a hull, a single propeller having a hub normallyemersed when the boat is under way and submerged surfaces laterall adjacent the propeller defining between t em a body of water free of obstruction beneath the propeller in which the propeller may operate and being subject to the lateral wash of the propeller.

6. A boat having a hull, a single propeller having a hub normally emersed when the boat is under Way and submerged surfaces laterally adjacent the propeller, one at each side thereof, but having substantial clearance therefrom to provide a body of water in which the propeller turns, said surfaces l extending rearwardly of the propeller, the reaction of such body. of water on the submerged surfaces counteracting the tendency `of the propeller to steer the boat.

7. A boat having a hull, a single propeller having 4a hub normally emersed when the boat is under Way and a submerged surface laterally adjacent the propeller but having substantial clearance therefrom to provide a body of water in which the propeller turns, the reaction of such, body of water on the submerged surface counteractng the tendency of the propeller to steer the boat, said (surface being movable to function as a rud- 8. A boat having a hull, a single propeller having a hub normally emersed when the .boat is under way and submerged surfaces laterally adjacent the propeller, one at cachiso side thereof, but having substantial clearance therefrom to provide a body of water in which the propeller turns, the reaction of such body of water on the submerged surfaces counteracting the tendency of the propeller to steer the boat, said surfaces being movable to function as rudders.

9. A boat having a hull the bottom of which presents inverted V sections flattening aft and having a single propeller projecting from` the stern of the type which operates with the hub emersed when the boat is under Way and counteracting surfaces located laterally adjacent toy said propeller at a suitable distance therefrom to be subject to the wash thereof.

10. A boat having a hull'the bottom of which presents inverted V sections flattening aft and having a single propeller projecting from the stern of the type which operates with the hub emersed when the boat is under way and rudders pivoted generally opposite said propeller and presenting counteracting surfaces located laterally adjacent to said propeller at 'a suitable/distance therefrom' to be subject to the wash thereof.

which presents inverted V sections flattening aft and having a single propeller projecting from the stern of the type which operateswith the hub emersed when the boat is under way and rudders pivoted generally opposite said propeller and lying when' in neutral position in two planes extending lengthwise of the boat and crossing above the water level, said rudders presenting i i counteracting surfaces located laterally adjacent to said propeller at a suitable distance therefrom to be subject to the wash thereof.

12. A boat having a hull the bottom of which presents inverted V sections flattening aft and having a. single propeller projecting from the stern of the type which operates with the hub emersed when the boat is under way and rudders pivotedy generally opposite the propeller organized andpoperating to undercut the water at the inside of aturn and to present a semi-planin surface on the outside of a turn whereby to ank the boat during turning, said rudders presenting counteracting surfaces located laterally adjacent to said propeller'at, a sultable d1stance therefrom to be subject to the wash thereof.

13. A boat having a hull, a single propeller of the type which operates with the ub emersed when the boat is under way,

said hull including a bottom surface which delivers a relatively regular `sheet of water to the propeller blades whereby to regulate the dip thereof and means to counteract the tendency of the propeller to steer the boat comprising a submerged surface adjacent the ropeller on the side thereof toward which the water is urged.

peller of the type which operates with the hub emersed when the boat is under way, said hull including a bottom surface Which delivers a relatively regular sheet of water to the propeller blades whereby to regulate the dip thereof and means to counteract the tendency of the propeller to steer the boat comprising submerged surfaces adjacent the propeller at opposite sides thereof and subject to the reaction of the water moved by the propeller. e

16. A boat having a hull, a single propeller of the type which operates with the hub emersedwhen the boat is under way; 11. A boat having a hull the bottom ofv said hull including a bottom surface which delivers a relatively regular sheet of water to the propeller blades whereby to regulate the dip thereof and means to counteract the tendency of the propeller to steer the boat comprising submerged surfaces adjacent the propeller at opposite sides thereof and subject to the reaction of the water moved by the ropeller, said surfaces extending rearwargly of said propeller.

17. A boat having a hull, a singlepropeller of the type which operates with the hub emersed when the boat is under way, said hull including a bottom surface which delivers a relatively regular sheet of water to the propeller blades whereby to regulate the dip thereof and means to counteract the tendency of the propeller to steer the boat comprising submerged surfaces adjacent the propeller at opposite sides thereof defining etween them a body of water unobstructed 4beneath the propeller to the action of which when moved by the propeller such surfaces are subjected.

'18. A boat having a hull, a single propeller of the type which operates with the ub emersed when the boat is under way, said hull includin a bottom surface which delivers a relative y regular sheet of water to the propeller blades whereby to regulate the dip thereof and means to counteract the tendency of the propeller to steer the boat comprismg a l submerged surface laterally adjacent the propeller vand subject to the action of the body of water moved b. the propeller,- said surface being movab e to function 'as a rudder.

19. A boat having a hull, a single propeller ofthe type which operates with the hub emersed when the boat is under Way,l said hull including a bottom surface Which delivers a relatively regular sheet of Water to the propeller blades whereby to regulate the dip thereof and means to counteract the tendency of the propeller to steer the boat comprising submerged surfaces adjacent the propeller at opposite sides .thereof and subject to the reaction of the Water moved by the propeller, said surfaces beingmovable 10 to function as rudders.

In testimony whereof, I have signed my name to this specification.

WILLIAM ALBERT HICKMAN.

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