US1087203A - Propeller. - Google Patents

Description

I. W. WALTERS.

PROPBLLBR. n APPLICATION FILED APR. 19, 19,10.

1,087,203. Patent-ea m5111914.

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JULIUS WM. WALTERS, 0F GLENS FALLS, NEW YORK.

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Specification of Letters Patent. Patented -Feb. 17, 1914.

appumionmea April 19, 1910. serial Nofsseso.

To all lwhom 'it may ooncem:

Be it known thatgI, J ULIUS W WAL'rERs, a citizen of the United States, residing at Glens Falls, in the county of Warren and State of New `York,'have invented new and useful Improvements in Propellers, ofwhieh the following is a specification.

My invention relates to propellers ofthe radial blade type. While'having-the particular relation specified, there are a number of features involved, which may be used with great ensuing advantage in connection with propellers of other types. 0n the other hand there are certain features which are of'particlar value when used in connection with propellers of the radial blade type, and it wil be noted upon an understanding of my invention that vthe entire number of features coperate with each other when combined together in the embodiment which I-'s'hall disclose to produce a propeller givingthe most eiiicient results.

In a great number of propellers in use at Ythe pr`esent'time considerable diiiculty is eX- perienced inimaking them efficient owing to each of several causes. By many propellers up ofthe watersboth" there .is a next tothe hub, and away from 1t, wththe result that the water is not in condition for a most eicient vpurchase to be had by the propeller upon it. 'Frequently this breakingl up of water occursnext the cutting edges of the propeller, with the result that the Aportions -o'f the blades in the rear of the :cutting edge are forced -to act ineliciently. The resulting slippage or so-called sli Vof the propeller is rendered greater by t is action of the propeller, andthe speed of the Vessel bef ing driven is correspondingly decreased. -InA connection with many vpropellers also there is considerable centrifugal action of th`e pro-1 peller on the waters next thehub, and the j water soacted upon is thrown out in such a1 manner as to project vit beyond the range ofi action of the outer portions -of the blades.z The slip of the propeller is also increased 'l due to this action. And in all of these in stances the breaking up of the water and the resulting irre lar action of 'the propellerv4 upon it, especially at high speeds, results in a vibration of the propeller and shaft which is transmitted to the machinery and the; frameof the vessel, becoming inmany instances vcry objectionable on account of the jarring of the machinery, and the unpleasant vibration of the walls of the vessel,

Many attempts have been made to over- 4the spiral form of screwpropeller has been used, and the multi-blade spiral, the vblades of which emanate from the huband follow a spiral of gradually increasing diameter, but none of them so far as I am aware, have been a successful solution of the problem in all of its phases. These diiiiculties may have been removed in a propeller'designed for a certain speed,- but at certain other speeds, the same propeller has been found inefficient, and a propeller of the same design'could not be made to work efficiently. So also in some propellers one dilficulty has :been sought to be remedied,I and in some zanother.

It is the object of my invention likewise, xto overcome the diiiiculties named, and I 'have so far succeeded that the propeller of .my invention operates at a greatly increased eliciency, and a propeller of the same design may beused over a wide-range of speeds with'the same eliicient action, breakin up of the water, and centrifugal action yo the .propeller on it, and the resulting slip having lbeen reduced to a minimum.

In the accomplishment of the object' lof ;my invention I use a multi-blade propeller. I -so shape .and associate the blade withthe Ihub and so form them and their driving Aedges and faces that all of the above-named difficulties are overcome in greatmeasure.

My invention will be readily yunderstood and appreciated from a consideration of the accompanying dr'awingsin connection nnanner of association and formation of the lblades of the propeller of my invention are the blades. The driving faces Aof the blades are formed commencing tangent to the hub .105 10 is the-hub of the propeller and 11 are as at 12. At this poi-nt the elements of the driving facesare substantially perpendicular toa transverse plane, represented by line 13, 13. Iextend the blades outwardly and rearwardly along a conical spiral curve,

until they reach a certain maximum diameter 14 at a point 15 in their length. From this point on I extend them along a helical curve at a diametery equal to the maximum diameter 14. I terminate the vblades before there is apparent overlapping in end projection of the propeller, the blades being terminated before they occupy an angle of 180 around the axis of the hub.

After leaving the hub the face ofthe blade instead of continuing perpendicular to a transverse lane 13,l 13, is increasingly inclined to it, t e rear edge of the blades being lagged behind the cuttin edge, until .a point at or near the point o greatest diameter is reached. Thereafter the incline of the blades to a transverse plane is maintained substantiall uniform. The blades also are formedfof7 increasing width from the hub outwardly, and are glven the crosssections shown in Figs. 3, 4, and 5, It will be observed that the blades are thickest at a point nearer the rear edge of the blade than thev front edge, or over half-way of the width of face of the bladev in anyinstance from the cutting edge to the rear edge. The sectional areas are substantially triangular in shape. Y

By virtue of the commencing of the disturbance ofthe water at the hub, the propeller in effect worming its way through the water in muchvthe same manneras does a worm propeller. Gradually the wateris acted upon by the faces of the blades which follow the spiral curve of increasing diameter rearwardly, until it is movin as a substantially solid column, in whic shape it is ready to be acted` upon and is acted upon by the outer portions of the blades, which are formed on the rearwardly extending spiral curve of substantially Y uniform diameter. Breaking up of the water due to f rotation ofthe blades adjacent the hub, and' due to `centrifugal' force is reduced to a minimum, and the solid body of Water ualwaysin the region of the propeller is constantly acted upon vby new portions of the blades.

hi h. v

nd that by simply increasing the incline of the blades rearwardly or in other words by simply decreasing the conical angle of the spiral curve on which the blades are formed V 6o with respect t the axis of the hub, l mayreadily adapt the propeller of my inventionto use at higher'speeds. This is illustratedl by the dotted lines in Fig. 1, the points at which the blades reach their maximum diameter of revolution for speeds of' 600,` 800,

blades, tangent to the hubs, there is little- Slip is therefore low and efficiency;

noemer 1000, 1200, and 1400 revolutions being indicatedl separately. It will be notedthat as the speed is increased, the conical angle of the cone of the spiral of the rearwardly extending blades is decreased. Preferably the maximum diameter of revolution 'of the blades is maintained substantially uniform in the designs for a wide range of speeds. lt is assumed of course the blades are elongated in order that the maximum diameter may be ,preserved when the conical angle is decreased. The propeller Lof my invention is thus made suitable for use at various speeds throughout a very wide range.

Despite its peculiar shape the propeller is so constructed that it will withstand all the strains imposed upon it under the most severe conditions of normal use without breaking, and this without impairing the efficient cutting action of the blade in the water. nearest the hub o n the rear edges of the blades, this thickened portion acting as a backbone as it were, and thus giving strength where strengthr` is most needed. By virtue of this provision also the blade is made to taper gradually from the cutting edge rear- The blades are thickest at points wardly substantially to the rear edge,

the action of the blades upon the water is made knife like, the solidarity vof the water acted upon by the propeller being thus further preserved. f, Owing to the fact that each blade occupies an angle less 'than 180 around the axis of the hub, they may very.

readily be made of such cross-section aste be quite rigid. It is owing to the ecient action of the propellerl'lpon the water in'the 'peculiar manner previous'y described, that the linear length of ,the b ades is reduced, and it is by virtue of this lreduction to such extent that they Aoccupy angles less than 180, without apparent overlapping in end projectionthat the action of the blades upon the water is made substantially independent, resulting in further increase in eciency.

Whatlclainlis: A propeller comprising a hub and blades 'extending outwardly and rearwardly 'om the hub along a 'conical spiral curve through 'approximately 180 degreesto. a predetermined maximum diameter and thence along a helical c lindrical curve of said maximum.

diameter ess' than 45 degrees whereb to prevent overlapping in end projection o the blades, said blades increasing 1n width 'om the hub to theipoint of mam'mum diameter thence decrea ends, the working faces of the blades commencing tangent to the hub'whereb to admit of free radial flow of the fluid om-the huband odset vortexing, said working faces continuing outwardly andbackwardly at an increasing inclination to the transverse plane of the hub, the rear edges of the blades `inwidth 17o-their ends 'and decreasing 1n thickness toward their lagging beh-ind the cutting edges up to the` ln testimony whereof I have hereunto set pomt of maximum diameter and thence bemy hand in presence of two subscribing wit- 10 ing uniformly inclined Whe-reb the 'pronesses. n peller is given worm action e ectingy the movement of the Huid in al substantially JULIUS WM WALTERS solid column, the outer cylindrical portions Witnesses:

of said blades acting upon the solid column A. C. VANDERZEE,

of the fluid. v .TosmPH KOBER.

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