US514835A - Francis e - Google Patents

Description

(No Model.)

P; E. MILLS. BODY OF LEAST RESISTANCE FOR VESSELS', 8:0.

No. 514,835. Patented Feb. 13, 1894.

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UNITED STATES PATENT @FFKCE.

FRANCIS E. MILLS, OF SAN FRANCISCO, CALIFORNIA, ASSIGNORTO HORACE A. DEMING, OF SAME PLACE.

BODY OF LEAST RESISTANCE FOR VESSELS, 800.

SPECIFICATION forming part of Letters Patent No. 514,835, dated February 13, 1894.

Application filed November 5, 1892. Serial No. 451,112. (No model.)

To all whom it may concern.-

, Be it known that I, FRANCIS E. MILLS, of the city of San Francisco, in the county of San Francisco and State of California, have invented a new and Improved Form of Solid of Least Resistance, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming apart of this specification.

In the drawings-Figure 1 illustrates the construction embodied in devices for use entirely immersed in water or surrounded by air. Fig. 2 illustrates the form when but two sides are to be subjected to the action of the resisting fluid medium and Fig. 3 shows for' purpose of explanation and illustration a single compensating wedge.

The object of the invention is to produce a form of body, eitherv solid or hollow, which, with a given length and end displacement, will pass through the air, water, or any other resisting fluid medium with the greatest sustained velocity, and the least expenditure of power; and also maintain a stationary position with the least anchorage, when opposed by currents of wind or water; such form to be applied to military or other projectiles shot through the air, submerged projectiles and torpedos shot through the Water, submerged vessels propelled under water, other uses hereinafter mentioned; and one longitudinal half of it to boats and other floating craft partially immersed in water.

To get the form required I first make a single compensating wedge, of the dimensions desired, and the shape represented in Fig. 3

in the accompanying drawings; that is to say,

a wedge (the bottom being'flat and level) the top of which tapers longitudinally and continuously in one direction to a thin horizontal edge, while the sides at right angles thereto taper continuously in the opposite direction to a'thin, vertical edge. Now, if this bodywere immersed in water, pressing equally in all directions, the pressure on the upper surface, acting alone, would tend to move itin the direction of its vertical end, while the pressure on the reverse part (the sides) would of itself tend to move it in the opposite direction; as these two opposing forcesmeutralize each other, the body would remain stationary. But if, by some extrinsic power, this body were moved rapidly and horizontally through the water, the upper inclined surface would impinge against and displace the water, while the reverse sides would constantly recede from it; and, as the displaced fluid could replace itself against the receding sides by its gravitating power alone, the replacement would be so slow as to leave no counteracting pressure on the reverse parts of the wedge butinstead of that there would be aconstant tendency to a vacuum there, which would retard its motion. vacuum, and also to restore the equilibrium of forces which existed upon the two opposing wedges when the body was stationary, I connect the two wedges by laterally intervening sides, whose transverse planes are at all points diagonal to the lines of taper of both. This I do by drawing a line through the longitudinal center of the tapering surface of the upper wedge, and cutting away the rectangular half of each, transversely, from this central line to the tapering lines of the bottom, all the way from one end to the other, leaving it in the form shown in Fig. 2, that is, athree sided body, one side a being flat, horizontal, non-resistant, with its longitudinal edges 'a' tapering all the way in one direction, and two equal transversely flaring diagonal sides 1) whose line 0 of convergence tapers all the way in the opposite direction, the flare of the sides commencing at the narrow end b where they are vertical, and increasing in degree all the way to the wide end, where they become horizontal, and merge into the flat bottom, each of these diagonal sides thus making, in its In order to prevent this entire length, a transverse twist of ninety the act of displacement, the water will be deflected spirally and relatively backward, directly into the vacuous spaces which are be ing left between the receding portions and the surrounding fluid, not only preventing a vacuum there, but imparting the force of its momentum to the reverse portions of the wedge, and thus counteracting the resistance opposed to its advance. In other words the displacement and replacement will be coincident, and reciprocal parts of the same movement. The more rapid the displacement the more forcible will be the impact of the displaced water as it is driven in upon the reverse portions of the wedge.

The form herein last described and shown in Fig. 2 embodies in two contact surfaces the principles underlying the solid shown in Fig. 1, and when this half is inverted, and placed in the water with the Hat side level and even with its surface, it represents the application of the invention to boats and other craft partially immersed in the water. It forms that part of the hull at and below the loadwater line. In connection with the said hull construction it is preferred to supply a keel as shown.

In all boats now in use, the motive inertia of the water which is displaced and set in motion by the passage of the boat through it is lost. Yet in all fast going boats, by far the greatest portion of the propelling power is consumed in producing that motion, and most of the power expended in producing it still resides in the momentum of that moving water at the instant it is being driven from the boat. In the form of hull herein described the larger portion of the displaced water, instead of being driven away from the boat, in the form of waves, to toss and vex all neighboring craft, and dash with destructive violence against the shores, will be driven against the receding portions of the boat itself, in the manner and with the effect hereinbefore described, leaving shores uninjured, and its smaller neighbors undisturbed. The momentum of the displaced water is utilized, and restores to the boat in a large measure the power consumed in displacing it; thus rendering possible a very high rate of speed at comparatively small cost for the power.

When the invention is to be applied to submerged projectiles, or to projectiles shot through the air, or to any other use where the body is wholly inclosed by the resisting fiuid, I unite to the half already described,

another half of the same dimensions and form, placing the Hat sides together so that their edges and ends exactly conform. This gives it four equal longitudinal sides, each twisting ninety degrees in its entire length, terminating and merging in two chiselform ends standing at right angles with each other, the twist of adjacent sides being in opposite directions, as shown in Fig. 1. Both ends being alike, this body will pass through the air, water or other fluid medium with equal ease in either direction, displacing and replacing the fluid on the principle of a compensating wedge, as hereinbefore explained. The angle of longitudinal taper, in these Wedges respectively, may be uniform from end to end, if desired, but to obtain the full effect of the principle the line of taper should be a regular curve, tangential to the line of motion at the wide end, and continuing on a single radius to the opposite end, as shown. The reason for this lies in the fact, that though the progressive motion of the body through the air or water may be very rapid, the lateral movement of the displaced fluid will be comparatively slow, and relatively toward the rear, thus throwing the culminating force of the replacement upon the rear portions of the reverse wedge, which by having the increasing angle of taper given it by this curve will receive a greater impulse forward. For most purposes it will be found desirable to round off the thin corners of the forward end, (sometimes the rear end also) but this can be done without materially impairing the effect.

For submarine projectiles and torpedoes, this form would prove exceedingly effective, and of great value in the defense of sea-board towns. The enormous resistance opposed by the ms inertia of water to a body moving swiftly beneath its surface, has hitherto so limited the speed and force of such projectiles, and enhanced the cost of employing them, that the most vulnerable part of a hostile ship (that below the water line) has been practically exempt from assault. But with a projectile made in the form herein described, such parts could be reached with destructive effect, either by a plunging fire through the air, or a horizontal one beneath the surface of the water. Besides those already enumerated there are various other uses to which I propose to apply this invention. Among these, are submerged or partially immersed supports for floating or ponton bridges, crossing rivers or waters subject to the flux and and reflux of strong tides, to floating stationary structures exposed to currents of water, to swinging ferry boats when crossing rapid streams, and to balloons and other structures for navigating the air, whether moving or stationary, to enable them to overcome the resistance of the atmosphere, or to withstand the force of the wind.-

For most of the uses herein mentioned itis best to make thelin es of thetransverse sections of the body straight, but where greater buoyancy with the same longitudinal dimensions is desired, as in stationary balloons and floats, these lines may be slightly convex without detracting very greatly from the effect, such curvature being indicated in some of the cross sectional views forming a part of Fig. 1.

Having now fully described the invention and mentioned the principal uses to which I propose to apply it, what I claim as my invention, and desire to secure by Letters Patcut, is-

1. A body of least resistance substantially as described consisting mainly and substantially of two laterally adjoined and longitudinally reversed wedges, connected and merged together laterally by four sides whose transverse planes are at all points diagonal to the lines of taper of both wedges, and twist transversely ninety degrees in their entire length, the twist of adjacent sides being in opposite directions, and all terminating in and merging into two chisel-formends which stand at right angles with each other, substantially as and for the purposes herein described.

2. A body of least resistance substantially as described which consists substantially of two laterally adjoined and longitudinally reversed wedges connected and merged together by four transversely twisting sides diagonal to the lines of taper of both, the twist of adjoining sides-bein g ninety degrees, in opposite directions, all terminating and merging in two chisel-form ends which stand at right angles with each other, the longitudinal taper of the wedges, respectively,being in regular curves commencing parallel with the line of motion below the load water line flaring upward and' outward transversely from the longitudinal center of the'inelined bottom to the load water line, the flare of'the sides commencing at the narrow and deep end, where they are substantially vertical, and increasing in degree all the way to the wide end, at or a little above the load water line, the flaring sides having a transverse twist in opposite directions, substantially as and for the purpose herein described.

4. A non-resistant device substantially as described having its adjacent surfaces subject to the action of the resisting fluid merged at one end in a chisel form edge, sloped upward on their longitudinal meeting edges from said chisel form edge to a plane atright angles thereto, and flared or twisted continuously in opposite directions from the chisel form end till they merge in the plane of the upper edge of the bottom slope of their longitudinal meeting edges substantially as set forth.

5. In a boat, or other floating craft partially immersed in water, a hull, which, at and below the load water line has the exterior form substantially, of two laterally adjoined and longitudinally reversed wedges, connected and merged together by flaring sides which in their entire length are transversely diagonal to the lines of taper of both, and have a transverse twist of ninety degrees, in opposite directions, the lines of longitudinal taper being regular curves, the horizontal curves commencing tangential to the line of the boats motion at the wide end, and continuing with a single radius to the narrow end, while the vertical taper starts parallel with the line of motion at the lowest point of the narrow end and continues on a single radius to the load water line at the wide end, substantially as and for the purpose herein described.

, 6. A non resistant device substantially as described, having its adjacent faces subject to the action of the resisting fluid merged at one end in avertical edge, and terminating at their opposite ends in a common horizontal plane, and tapered continuously on a single radius between said ends substantially as set forth.

FRANCIS E. MILLS.

Witnesses:

P. B. TURPIN, SoLoN C. KEMON.

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