US1644725A - Boat - Google Patents

Description

@et 11, 192m 19449725' W. A. HIQKMAN BOAT led Deo. 2. 1922 3 Sheets-Sheet l Y @y w @et n, i927., EAMES w. A. HICKMAN BOAT Filed Dec. 2. 1922 3 Sheets-Sheet 2 Halcsmmm LAZE Oct@ 11,1927.,

W. A. HICKMAN BOAT Filed Deo. 2. 1922 5 Sheets-Sheet 3 Patented oct. 11, 1927.

UNITED STM'ES WILLIAM `mamar momie, or wnsr MYsTIc, coNNnczrIoU'a,

BOAT.

Application niet! December 2, 1922, Serial No. 604,596, and inlColombia, South America, October 28, 1922.

This invention pertains. to improvements in boats and more particularly, though not exclusively, to improvements in boats of the type described in United States Letters Pat# ent No. 1,204,355, issued to me November In the drawings, which showfa preferred form of one embodiment of my invention:

Figure 1 is a side elevation of a hull 1n 10 which the center keel, throughout the greater sides, being generally rectangular in plan but in which the stern lis angled somewhat to permit play of the rudders in opposite dlrections- Fig. 4 is a rear elevation of the board which constitutes the bottom of the stern of the boat;

Figs. 5, 6, 7 and 8 are diagrammatic sec-r tions through the bottom of the boat on the lines 5 5, 6 6, 7 7, and 8 8, respectively, of Fig. 3;

Fig. 9 is a plan taken below the section line .9 9 ofv Fig.'10,` and shows the preferred double-'acting side plate rudders connected to be operated conjointly in both directions yand preferably, as illustrated, inclined rela-I tive to the central 4longitudinal plane of the boat; and

Fig. 10 is a rear elevation of the stern of the boat, being partly in section.

' Referring to the drawings, and to the preferred form of my invention selected for illustrative purposes, I have disclosed a boat of the inverted V-bottom type which is the subject-matter of, my United States patent above referred to, presenting a hull generally rectangular in plan and having the keel 11 located above the chines 12, from jwhich the sides rise substantially vertically, the elevation of the keel above the chines being greatest adjacent the bow, asfshown in Fig.`

8, and

l adually decreasing toward the stern of the oat, as shown in Figs. 7, 6 and 5.

The bottom of the boat is preferably fiat at the stern proper, being presentedv by the bottom of the stern plank 13 shown in Fig.v 4.

In boats of this inverted V-bottom type where suiicient power is provided, for propulsion in proportion to the weight and unmaking a very` considerable commotion., and being very inelicient until suiiicient speed is attainedso that the stern will rise andthe boat will proceed on a generally even keel. This to some extent limited the eiiicient use ofboats .of the inverted V-bottom type to those having very great power in proportion to weight. It is among the objects of the present invention to greatly increase the aciency of this type of boat under all circumstances, and particularly to improve its action where the power applied, in pro ortion to the weight, is rnotsuilicient to ra1se the hull so much out of the water as above described. 'Ihis feature of my invention also serves in boats of the inverted V-.bottom4 type to prevent the depression of the stern when operated at relatively low speeds, and to keep generally on an even keel fore and aft, boats travelling at relatively high speeds, in which the weight in proportion to bottom area and power available are suited for commercial purposes as Adistinguished from pleasure or racing craft.

I have found that the depression of the stern in my earlier boats of the inverted V- bottom type was due; to the fact that the bottom adjacent the stern presented an an le i of incidence with which the proper-distri ution of supporting surface fore and aft was not attainedA and which coupled with the (adhesion of the water`A and the atmospheric'l pressure overcame the li ing tendency oc- .to so thatthel boat plows through the water,`

soy

casionedby forward movement of the boat until avery considerable speed was attained with attendant proper distribution of supporting surface relative to weight. By pro'- viding, as in the inventionl shown in the present application, surfaces on the bottom of the boat aft in which the angles of incidence increase, the stern is vnot only prevented frorn lowering at very low speeds, but is raised to the desired position to maintain the boat on a generally even keel fore and-aft at a much lower speed than where these increasing angles of incidence are not provided. The increased angle of incidence aft elevates lthe stern even at low speeds thus preventing the bow from rising to an undesirable extent, and presenting submerged sec tions much easier to advance through the water than heretofore. The underwater sec- 20 tion presented not only has a decreased maxv,imum cross-sectional area, but presents to the water surfaces angles to provide an improved lresolution of forces, both lifting and advancing, the adhesion of the water and the' ,stern, as is best shown in Fig. 2, which is on an enlarged scale. I have also found that the, advantages attendant to these increasing angles of incidence are best supplied by providing aft a similar reverse curve of the chines, this reverse curve of the chin'es being preferably somewhat less than the reverse curve'of the keel so that the two may meet at the stern 13 of the boat in-a straight line, or a substantially straight lineA transversely considered as distinguished from thel angllled stern line presented in the construction own in my United States Patent 1,204,355-

referred to, and directed to the earlier type of inverted,V-bottom boat. y

Where, as` in the present application, one or more surface propellers 15 are used, the advantages of the general type of hullherein sh wn are particularly availed of because the h 1l, maintaining a generally normal position fore and aft even at low speeds or when heavily loaded, delivers from beneath the stern of the boat the practically Hat sheet of water in which these propellers act most eiciently. While the increasing angle of incidence mav be provided in hulls in which the vstern line 13 is not straight, and even when so used has advantages particu- .larly in connection with the surface propellers, I have found that the surface propellers act more efficiently where the stern line is straight as distinguished from angled. The surface propellers of the boat shown in the present application have 'their hubs practically touching the water as distinguished from elevated considerably above-the water in my patent above referred to. rIhis lowering of the propeller hubs not only increases the depth of dip of the propeller or propellers of any 'given diameter, but enables me to increase the eiiiciency for any given dip,

because as the diameter of the propeller is decreased, without decreasing the working area, the speed at which the propellers may be efliciently driven, and the average amount of blade immersed at all times, is materially increased. While for some arrangements a single surface propeller is desirable, I prefer touse multiple propellers and in the present application I have shown these as four in number, of which the outer two are somewhat longer than` the inner two, so that the water acted upon by the propellers considered as a whole will present fewer counteracting currents and so that the opportunity for cavitation will be reduced.

As the boat passes through the water, substantially all spray is th/rown inwardly... being caught in the V-shaped recess between the chines and the keel, considerable air also being' entrapped so that the boat as it A proceeds at high speed is riding to a considerable extent :on a cushion of air and spray resulting in a well distributed positive pressureunder the bottom aft of the \forward waterline. In a boat of ordinary V- bottom type, as distinguished from the inverted V-bottom type, "the tendency 0f the hull is to move the water laterallynot only above the surface where it takes the form of sprav, but below the surface where each particle, dragged forward' somewhat by the hull, has a lateral movement which tendsy greatly to decrease the speed of thev boat not only because of energy unnecessarily used ,in moving the water, but because ofthe negative pressure, engendered by the lateral outflow, on the bottom surface vof the boat when travelling at any considerable speed. In boats of the type here under considera tion, there is little or no tendency to move the particles of water laterally, the tendency being rather to move the particles downwardly and the reaction of this contributes to the lifting of the boat so that power ordinarily wasted. in moving water uselesslv is here to a verv considerable extent utilized in elevating the hull so that the resistance of the boat to forward movement is, decreased and, considering the factors of weight and speed, considerable power is saved. vThe increasing angle of incidenceA adjacent the stern of the boat, as herein described. materially adds to the improved effect of lifting the boat because the lifting is more uniform than in my' earlier type of inverted V-bottom boat, the reaction of the water adjacent the stern tending t`o lift the boat being materially increased.

Where, in my earlier patent, I have shown twin rudders to be operated one at a time to turn the boat, I have found that by operating the rudders conj ointly, by adapting them to swing in either direction together, the steering is markedly improved, there being -less retardation of the boat in connection.

with turning at any given speed at a given radius by the combined action of the two rudders than by the action of the rudder at the inside of the curve only, as in my other patent referred to. The operation of the rudders is best shown in Fig. 9, wherein the ,rudder-controlling shaft 2O is provided at an outer end with a pinion 2l meshing with thefrack 22, which is connected by rods 23, 23 with the rudders 24, 24.. The action of the rudders 24, 24, cooperating tol turn the boat, also tends to tip the boat laterally toward the inside of the curve, while oppos` ing any tendency to slip or skid arising from the contact of the water with the bottom of l theboat. This anti-skid action is materially increased, turning power is increased and retardation diminished by inclining the pivots 25, ,25 on which the rudders are swung, inwardly toward their top so that the rudders are angled relative to each other when viewed from the stern, as shown in Fig. 10. Thus if the rudders, as viewed- 1n Fig. 10, are swung to the ri ht 'with a view to turning the boat to the right, the rudder at the right-l1 and side of Fig. 10 will promptlly ,undercut the water, tending to drag down the inner or right-hand side of the boat, while the other rudder at the left of Fig. 10 will, by reason' of the angle atz which it cut-s the water, tend to raise the left-hand side of the boat, thus contributingrto the bank- "ing of the boat during turning, while also contributing its share to thev turning moment.

It will be understood that with a view to permitting the rudders to be swung in both directions, I have altered somewhat the shape of the sides of the boat adjacent the stern from the construction illustrated in my earlier patent, so that the sides of the stern', instead of being square, are angled at 26, 6. The axes of the rudder pivots 25,

25, as illustrated, lie in a common plane extending transversely to the boat and generally vertical relative thereto.r This` angle may for some purposes lbe varied in one direction or the other, but I have found that Where the rudders are angledv as viewed from the stern V(Fig. 10 it 1s unnecessary, and

f even perhaps un esirable, to angle the pivots of the rudder as viewed from the sides oftthe boat. f

While I have shownA and describeda pre- -angle of incidence to the ferred form of one embodiment of mv improved boat, it will be understood that vari. ous features thereof are useful separately and that considerable changes in structure and in the combination may. be eected without departing from the scope of my invention which is best defined in the following 4. A boat having a hull with sides free of y inward inclination or tumble-home and a bottom presenting inverted V sections gradually broadening aft 4in which the angle of irridence of one or more surfaces increases a 5. A boat having a hull with sides free of inward inclination or tumble-home and a bottom presenting inverted V sections grad-v ually broadening aft, the bottom presenting adjacent the stern a surface having a greater water than surfaces nearer the bow.

6. A boat of the gliding or semi-glidin type having a propeller, the hub of whichwhen the .boat is at speed lying above the level of the Lsheet of water immediately behind the boat and in which the bottom presents increasing angles of incidence aft.

7 A boat in which the keel is generally above the level of the chines presenting an inverted VL-bottom section between the chines, the angles of the bottom sections where they meet at the keel gradually becoming more, and more obtuse toward the stern, the keelcurving adjacent the stern to present increasing `angles of incidence to the water. f

8. A boat in which the keel is generally above the level of the chines presenting an inverted V-bottom section between thev chines, the angles of the bottom sections where they meet at. the keel gradually becoming more and more obtuse toward the stern, the chines curving adjacent the stern to present increasing angles of incidence to the water. w

9. A .boat in which the keel is generally above the level of the chines presenting an inverted V-bottom section between the chines, the angles of the bottom sections where they meet at thel keel gradually becoming 'more and more obtuse toward the stern, the keel and chines curving adjacent the stern to present increasing angles of twin rudders llung aft, the axes of which incidence to the water.F

10. A boat having a hull with-sides rising tudinal of the hull. 10 substantially vertically from lateral chines In testimony whereof, I have signed my 45 and a bottom between the chines formed as name to this Specification.

a single concavity presenting inverted V sections gradually flattening aft end having WILLIAM ALBERT I-IIQKMAN.

rlie in upwardly converging planes longi-

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