US885174A - Propeller-wheel. - Google Patents

Description

, siding at Grand UNITED sTA'ITEs 'PATENT.` oFFroE. f

HARRY J. PERKINS,.OF GRAND RAPIDS, MICHIGAN, ASSIGNOR OF ONE-THIRD TO FRED- ERICK L. PERKINS. AND .ONE-THIRD TO CHARLES E. PERKINS, BOTH ,OF GRAND RAPIDS,

MICHIGAN.

PROPELLER-WEEEL.

Specification of lhetters4 Patent.

Patented pnl 21', 190s.

To all 'whom 'it may concern:

Be it known that I, HARRY J. PERKINS, a citizen of the United States of America',y re- Ra ids, in the county of Kent and State of Niichigan, have invented certain new and useful Im rovements -1-n Propeller-Wheels; and I do ereby declare \the following to be a full,'.elear, and exact description of the invention, such'as enable others skilled in the art to which "1t appertains to make and use the same.

My invention'relates to` improvement inl propeller wheels, and 'more particularly to marine propellers; and its object` is to provide an 1m roved weedless wheel that is to say a w eel that will not foul with grass weeds or the like; to provide an im roved construction whereby the blades o -such .weedless wheels are rendered more effective; and toprovide the same with various new and useful features hereinafter more fullyl described and particularly pointed out in t e claims.

My invention resides in the novel formation of. the blades substantiall as lhereafter described, reference being had to the accompanyingdrawings, in which:

Figure 1. is a rear elevation of a wheel embodying my invention; Fig. 2. a side elevation of the same; Fig. 3. an elevation of the f l'rward side of a wheel; Fig. "4. a horizontaj section on the line 4-'421 of Fig. 1.; Fi a transverse section on the line 5-5 ofi 1'; and Fi 6. 4a diagram illustrating the utlines of t e wheel when viewed in line `.with its axis.

Li'ke numbers refer to like partsiin all of the `figures.

1I represents the'hubof the wheel; 2 theblades of the same, which blades are of pe- .culiar formation, to-Wit when .viewed in dius vector, R is the radius of the hub, 1' the radiusof the circle 7 vand 0 the polar angle, and thence is prolonged in substantially an arc 10 having aradius '12 substantially equal .substantially on .a radial line vertical to la 'Ward edge presents su where p is the ra,

to the radius of the wheel and with its center on a line struck from theouter end of said curve and perpendicular to a line tangential to the outer end of` said curve.' The blade terminating in a substantially semi-circular outline having a radius of about one-fourth ,of the radius of the wheel and with its center radial. line extending through the starting point of the forward edge. From thence theprear outline' 14 of the blade is o positely curved to form a ta er to the bladlc) joining the semicircular outline of the end at a tangent thereto and `joining the hub substantially ocpposite the startin point of the for# Kad e ge, of the blade an. tangential to the Viewed in 1plane projection at right an les to the axis o rotationeach blade at its orcurve extending at the middle across the hub near the forward end -thereof and outward to` stantially a cycloidal the periphery the end 11 of the blade showl ing a` flattened arch' curve, and the reared e 14 of the same a reverse curve, substantial y as illustrated'inFig. 2.

s In a transverse section, the blades are made concave on .the rear surface to provide increasing axial pitch rearward, and thin at the edges with a thickened middle portion,

as in Fig.. 5.Y

On the various pitch circles (that is, various circles concentric with the axis of rota-m tion), the blades are formed with substantially equal axial pitch or lead.

` In operation the forwa'rd edge of the blade moves through the water at an acute a le lto Said edge, and thus cuts the water w 1th,a1v

sliding motionalong said edge, whereby any weeds, grass. orfother obstructions engaged thereby will slide alonglsaid edge toward the periphery, and be disc arged froml the outer end of the blade. The Wheel is thus made self clearing and willnot become fouled, and .at the same .time the blade Vis made effective throughout its entire surface which is not the case in the unusual forms of so-called weedless wheels, which have the inner portions of the blades more nearlycircumferential to theI hub. In designing or laying out this wheel, I pursue the following method which enables me to secure the'ldescribed form with certainty. Referring to Fig. 6. for illustration,-

`I proceed as follows:A Draw. a horizontal line I 4 and a vertlcal line 5 crossing the same near the middle; about'the point of intersection of diyide this arcinto an theselines, Inext strike the circles representing the boss or hubl (the exact "diameter of which hub is not material); around this hub strike another circle 6 of substantially onethird the full diameter of the wheel; with 'the intersection of the'line 4 and the circle 6 as a center, strike the arc 7 of ninety degrees and having a radius equal tothe distance frm this center to the surface of the hub and v number of equal parts (six being used in t 's instance); divide the lower half of the circle 6 by equidistant radial lines 9 equal in" number to the divisions of the arc 7;fdraw vertical lines from the points of division of the arc to the line 4 and prolong the same in arcs 9a'concentric with the circle 6 to successive points on the radial lines 9; form the harmonic -curve 3 touchin these successive points on the radial lines. his profiles the harmonic curved portion of the front edge of the blade. Next prolong this line `3 in an arc- 10 having a radius 12 substantially equal to the radius of the wheel and with -the center of said ,arc 10 Ona line perpendicular to the tangent at the end of the arc 3, and join the outer 'end of this arc tangentially withan arc 11 having a radius 13 of substantially'onafourth of that of the wheel and with its center `located at the intersection of the fline 5, and the line joining the center of the arc 10- and the point of tan enc'y`of the arcs 10- and 1 1, and complete t e outline of the blade dproiile by an oppositely curved line 14 joine tan entially to the arc 1l at one end and to the ub tan' v gentially at the other end.

`Any approxnnate cycloidal curve will ro erly proile this forward edge. of the Ela es at right angles to the previously described prolile. Now by prolonging the working or rear surface offthe blade circumferentially and rearward from this forward edge on the respective pitch circles, so that its surface throughout is of substantiall the .same itch. or lead the wheel is comp eted and wlll be found to effectively convert the power appliedand that any weeds or other obstructions engaged b lcarried outward along t e .edge of the same and discharged at the peripher of the wheel.

.Obviously the area of the lade may be varied' by variation of the radius 13 and changin the location of its center and of the center o the radial lines4 12 to connect the radius 10 tangentially with the lines3 and 11;

" or varyingthe-,location or curve of the rear line 14, will in no wisealect the essential features of the 4wheel-or depart from the So also, whether the be immateria 'radius of the entire wheel and wit the blades will" be What -I claim is:

1. lA ropeller wheel, comprising a hub, and a b ade whose forward edge when projected on a plane' perpendicular to the axis commences at a tangent to the surface of the hub, and extends outward therefrom in a substantially harmonic curve for 180 degrees,

and .thence is prolonged outward in a arc having a radius substantially the same as the radius of the entire wheel and with its center on a line struck from the outer end of said curveand perpendicular to a line tangential to said curve at its outer end.

2. A ropeller wheel, comprisin a hub, and a 4b ade whose forward edge wien projected on a plane per endicular to the axis, commences tangentia to the hub, thence extends s irally around the hub in arharmonic curve or 180 degrees, and thence is prolonged in. a curve having a radius equal to the radius of the entire wheel and with its center on a line Istruck from` the outer end of said curve and perpendicular to a line tangential to said curve at its outer end, said edge bein curved rearward in substantially a cycloida curvewhen projected on a plane parallel to the axis.

3. In a propeller wheel, a hub, and a blade whose forward edge when projected on a plane at ri htan les to the axis begins tan- .gential to't e su ace of the hub and thence extends spirally, around the same in substantially aharmonic curve to a .oint distant from the center dna-third the ra ius'of the entire Wheel, and thence is prolonged in an arc having a radius substantially e ual to the its center on a line struck from the outer end of said curve yandperpendicular to a line tangential to said curve at its outer end.

4. In a propeller wheel, a hub, and a blade whose forward edge when projected on a plane at right angles to the axis commences tangential to the surface of the hub, thence extends spirally outward in a harmonic curve to a point distant from the center one# third of the' radiusof the wheel, and from thence is prolonged outward in an arc of'substantially the same radius as the entire wheel and with its center on a line struck from the outer end of said curve and perpendicular to a line tangential to said curve at its outer end, the end of said blade being prolonged in a semi-circular outline having a radius of substantially one-fourth of the entire wheel, and

the rear edge of said blade being of a reverse' curved form and 'oining tangentially the end curve and the hu j In testimony whereof I affix my signature in presence of two witnesses.

HARRY J. PERKINS.

'Witnessesz "PALMER A. JONES,

LUTHER V. MoUL'roN.

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