US2460902A - Propeller - Google Patents

Description

Feb. 8, 1949. l ODOR 2,460,902

PROPELLER Filed March 9, 1945 2 Sheets-Sheet 1 Feb. 8, 1949. R. K. QDOR 2,460,902

PROPELLER Filed March 9, 1945 2 Sheets-Shet 2 JW Fwy/{00%. 9% AW? -/7WW7V&/%WWV Patented Feb. 8, 1949 warren star as PRcPELmm RalphKaOdcr, Edmond, Qllaaiassi nur to Ellie Vornadd, Trust. Oklahoman-City, Okla-h c fidu:

ciaryti-lustloffolflahorha Application-Max:113, 1945;" Serial No.1 5 $1 ,740"

This? invention; relates: to. propellers; andma principaliobiiect, iszto pmvideea propeller blade or -g; enerally improved. characteifistice ashereine aiter more: fully set forth:

More; specifically, .ant-object:-oif. theinventiom is toza provide a propeller exhibiting a materially increased capacity for moving air or; otherfluid aszcomparedswithsthe propellersof the prior'art. 7 Another object :of. the; invention is to provide azpropeller capablewof projeetingaa stream'of'airovenmaterially greater distances than; hasv been possible withmropellers of: the prior; art? Contributing topthis: latter objectiveythe-invenrtiontfurthere contemplates provision-off apropeller bladahavinga formation-which permits the-root portion thereof to participateato a materially greater degreethan lheretoioreronsideredpossible in-the primary-functionsoi the blade-to move; air or other.- fluid. I

The. invention: resides further-- in certaimof the structural: details; of the; blade hereinafter described! and. illustrated a in' the; attached :drawin wherein:-

1;is;-an axialziview ofzapropeller blade-made in; accordance :with thei -invention; Eig. 2:is;:-a: tip endviewzof the-"blade: shown in Big: 13;?

Fig: :3iis a face view ofrthe blade Y Fig.- 4 is a" section onthe line 4"-4, .Eigm- 3",

Figs; 5,6,' 7; ancl 8' are transversesectional views of the-bl'adetaken respectivelyvin planes indicated by thereference"letters a a; 5-4); 0-0; and d iivFig: 1*; a

Figa 9 is an axial view of apropellerhaving blades made in accordance with the -invention-y Figs; 10; 1 1; 12 arediagrammatic viewsillustratingthe physical characteristics of the blade andthe manner-inwhichit maybe laid outfor construction; and

Fig; 1'3 is" a development: of V the conicalsurface and; diagram ofiFig: 127: Y

WithreferencefirsttoqFigs; 1; tO"8?OfthB"d1-'E.W=- ings; the blade" therein illustrated as one em'bodi ment' of theinvention' comprises a cylindrical hub: I- to which the-blade -2 issecured through-s-the medium of'a fitting}, said fitting having a flange 4 which" is suitably attached to-- the hub and-a projecting portion 5' shaped in conformity-to the' contour of: the root of the bladeand to which theblad'e-is secured bymeansof rivets '6. It will be understood that; in the aforesaid -figunespf the drawing, a single blade has been shownion-purpose of'illustration; andthat a completepropeller would 'preferabl yemploy twcr or-more such blades uniformiy spaced arounrfithe-axie of the hub lit' a. Claims- (cluim sar 2;- accordanceawithtthe xccnyentionaliapractice; as illustratemiforxexample; in; Eigrpflp Withi.,- f1mthen refierence: to, the-drawin s",

thrush-facet "heft-the: blade-g zl-exhibits'; curyature I both: radially; (withrgnespect to; ther aXis';.of:-th,e

hub):- and transyersely between;thei-leadingqedge I e rand?theztrailineredge 9;: as best illustrated: in

thessectional; views: of Fig-mtand l lies. 5.--tc,18 in.c1usiv: e;-. Itisatobe noted that; both thez-radial transverse; curyatures; of; the -face: decrease plifl 'iessively-irom theroot lfiiOf-llhfit blade toward thestip-i l Stilhiurther; and with ;further refer,- encestml iigsafi:to;8;inclusiue;,the bladev an -legalse decneases from. the: root; toward theatipof the blades Inlthezpresent instance,- thez--bladeback corresponds inzformtorthe thrustiace the blade being oflsubstantially uniformathickness through:

out r Their)articular shapetand contour-of the-blade iszaiunetion; ofyithe. curved surfaceof; a-r-ight; cone;

' sneer; theroct lreappears:zonzthczcumedsurface ofrzthesconeaasramapproximate circle;indic.ated inaEig. lllabyl thesretenencetnumeral? l2 ,'which ri$ centeredgi preferably; in at;pointc-predeterminedly relaixed'toatheheightrand radialidimensionsz-ofathe coneiandwithdeferencetozthexdimensicns vof ti'ie 1 extends at an; acut'etangle to a rightfline lfiion the suri'a'ceiof the cone extending from the apex l6 and' 'also tin-tersectings the approximatetceriter Mi In the present instance, this angle it'b'etween the said-reenterllneMSYanwthe right line-- l5 -is approximatelyswfi" Theriotaryi axis ofa the blade and ofra propeller-imwhich the blade :is employed is indicatedmmthesurface-oftthecone-by: av line il'l' which intersects: the line= [3: at? right angles;

defined bytwo lines lzq and illl which-extendgfrom the opposite' sides oflthe circle l2 to thepoint wherethe center line: leiintersectsthe axis line I 1 this point of intersection being designated by the reference numeral? 2 I and iti-is to-be--'noted that 'i thetht cur-vedsurface of the cone-which is embraced by the lines I9 and 2B and the circle l2 and which represents the outline of the propeller blade is so disposed that the part of the said area which corresponds to the tip portion of the blade is more remote from the apex of the cone than the part of the area which corresponds to the root of the blade and that these parts are offset respectively to opposite sides of a right line represented, for example, by the line I which extends on the cone surface from the apex of the latter. the longitudinal center line I3, representing the major radial dimension of the blade, will be curved, and that the elements in the transverse direction between the leading and trailing side edges of the blade will also be curved as previously It is apparent that with this arrangement .5, As set forth above, the value of 30 for the angle or has been found to afford a blade of highly 1 desirable characteristics.

set forth. By reason of the fact that the root 1 portion of the blade is closer to the apex than the tip portion, the curvatures of the blade both radially and transversely will be more acute in the root portion than in the tip portion.

It will be apparent from the foregoing description that the blade, entirely aside from the general curvature characteristics set forth, will have a special contour constituting a function of the conical surface on which the blade is patterned and that these contour characteristics will vary somewhat in accordance with the angular position of the line representing the axial center line of the blade on the conical surface. Thus, if the line l3 were arranged so that the angle a is less than that shown in the drawings, the pitch of the blade will be correspondingly decreased, it being apparent that when the line I3 is in conformity with the line 15, thebla'de angle will be 90 throughout and the pitch zero. Similarly, a rearrangement of the line IS in the opposite direction from the position shown in the drawing will tend gradually to increase the pitch to a maximum where the line 13 lies in a plane norinal to the vertical axis of the cone, such plane being indicated in the drawings by the line 22. In any of the various positions which the line l3 might assume between the lines 15 and 22, certain essential characteristics related to the conical surface will be retained. In general, I have found that the disposition of the radial center line i3 as shown in the drawings, in the neighborhood of 30 removed from the line l5, will afford a propeller .of desirable overall characteristics, although it is apparent that for special purposes, a blade configuration corresponding to a different position of the line l3 may be found more suitable. s-The specific. manner of laying out the blade in accordance with the invention is as follows:

- A right cone is selected wherein the height as measured on a line normal to the base and intersecting the apex is equal to the diameter of the base. A line'is then drawn around the curved surface of the cone parallel to the base at a vertical distance from the apex corresponding to the desired radius of the fan. The diameter f the cone at this line will be equal to the height. In Figs.10,to 13 inclusive, the reference numeral 22 indicates this circumferential line. The circle 12 is then inscribed on the curved surface of the cone from a center in the line 22 and witha diameter equal approximately to of the radial length of the blade which in this instance is, say, 8". The circle l2 will, therefore, having a radius of 3". The right line [5 is then drawn from the apex through the center I4 of the circle l2, and the line 13, corresponding to the longitudinal center line of theblade, is drawn through the The determination of the position of the line i3 also establishes the point on the circle 12 corposition of the rotary axis of the blade, and this is done by laying off a cord 8" in length from the point i8 along the curved line 13. In Fig. 11 the point where the cord meets the line [3 is indicated by the numeral 2i. The said axis of the blade may then be indicated by a line i i at right angle to the line i3 through this point 2|. The line l8 which'corra ponds to the root sectionof the leading edge 8 of the blade is then laid off, this being in the nature of a straight line tangential to the circle l2 and intersecting the point 2i. The line 20 is established bydrawing an arc with a radius equal to the diameter of the circle l2 from a center which causes said are to, intersect the pcint 2i at one end and to join the circle l2 at the other end in a tangential direction. The area of the surface of the cone bounded by the lines l2, l9, and 29 represents the contour of the thrust face of the blade.

One of the important characteristics of a blade made in accordance with-this invention is its ability to project a substantially solid column of air which, by reason of a vortical effect set up in the column by the blade action, tends to resist disintegration and to maintain its form for a relatively extended period, the result being that a propeller incorporating the blade is capable of projecting air over relatively great-distances and at relatively high sustained velocities." This characteristic is of material value in creating a circulation or turbulence of air within extended spaces'from a single source, and also in moving air in a sustained column over long distances. It has been found, for example, that propellers made in accordance with this invention placed in series at spaced intervals can be made to sustain cones departing from these relative dimensions will still afford a blade of superior characteristics, and it is to be understood thatconsiderable latitude is permitted in these respects. It is to be noted also that while Fig. 13 constitutes a development of the conical surface and associated diagram shown in Fig. 12, the line 2!] in both cases is a true are drawn from a radius corre sponding to the true diameter of the circle I2.

I claim:

1. In a propeller, a blade having a thrust face which substantially defines an area of the curved surface of a right cone, the main body of the posed with respect to the propeller axis so that v a plane normal to said axis will intersect both the said point of convergence and the said center; the line on the surface of the cone which corresponds to the intersection of said plane with the said face of the blade, and the line on the surface of the cone which corresponds to the intersection with said conical surface of a plane containing both the axis of the cone and the said center, diverging from said center at an angle in excess of zero and not exceeding forty-five degrees, whereby the blade will have curvature in directions zboth radially of the blade and transversely between the leading and trailing edges of the latter.

2. A propeller according to claim 1 wherein the said angle of divergence is approximately 30 degrees.

3. A propeller according to claim 1 wherein the right cone has a base diameter equal to its height.

4. A propeller according to claim 3 wherein the said angle of divergence is approximately 30 degrees.

5. A propeller according to claim 1 wherein the distance of the said point of convergence from the nearest point on the circumference of the circle is equal approximately to one-third of the diameter of the latter, both as measured on the said conical surface.

6. A propeller according to claim 5 wherein the said angle of divergence is approximately 30 degrees.

7. A propeller according to claim 1 wherein the point of convergence of the edges of the said root portion of the blade lies in the axis of the propeller.

8. A propeller according to claim l wherein the trailing edge of the said root portion of the blade appears on the conical surface as an arc of a circle having a radius corresponding to the diameter of the circle representing the body portion of the blade.

RALPH K. ODOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 21,443 Gilbert et al. May 7, 1940 602,651 Adam Apr. 19, 1898 1,001,951 Hawkins Aug. 29, 1911 2,199,823 Kessery May '7, 1940

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