US1857327A - Propeller - Google Patents

Description

J. H PILET May 10, 1932.

PROPELLER Filed Aug. 3, 1929 INVENTOR. Joy/vb. 1 0.57?

ATTORNEYS Patented May 10, 1932 UNITED STATES JOHN H. PILE'I, or SAN FRANCISCO, c LIronNra PROPELLER Application filed August 3, 1923.1 Serial 1w... 383,246. I

My invention relates to improvements in propellers, and it consists in the combinations, constructions and arrangements hereinafter described and claimed.

; An object of my invention is to provide a propeller that may consist of two or more blades, these blades having a greater pitch than the usual propeller, and the ends of the blades are turned inwardly with respect to the blade lengths for presenting spoons adapted for gripping fluid as the propeller is revolved. I have found that this spoon type of blade will hold the water to a greater extent and will prevent slippage. This results in a blade which will give greater power when turning at a less number of R. P. M. than a standard blade.

I have also found that a blade slightly concave, the concave portion gradually dimin- 0 ishing as the tip of the blade is reached,

will give'a greater propelling force than will a blade not so designed.

A further object of my invention is to provide a device of the type described which is extremely simple in construction and which is durable and efficient for the purpose intended.

Other objects and advantages will appear as the specification proceeds, and the novel features of the device will be particularly pointed out in the claims hereto attached.

My invention is illustrated in the accompanying drawings, in which:

Figure 1 is a side elevation of the device, Figure 2 is a view similar to Figure 1 except that the propeller has been rotated through ninety degrees,

Figure 3 is a rear elevation, and Figures 4, 5 and 6 are sections along the lines 4-4, 5-5 and 66 of Figure 2.

In carrying out my invention, I provide a propeller having a hub portion 1 that is provided with a bore 2 for receiving a drive shaft. I show the propeller as being provided with two blades 3 and 4, each being identical with the other. A description of one will therefore suffice for both. It is obvious that more than two blades may be used without departing from the spirit and scope of my invention.

:Figure' 2 shows the blade'3 as extending away from the axis 5 of thepropeller at ap proximately an angle of forty-five degrees. The blade has a concave face 6. The curva ture of the face varies from a position nearest the hub to one near the tipof the blade, Figure 4,shows the face 6 as being hollowed. out. The section shown in Figure 4 is taken near the hub -1 as shown by the sectionline 4-4 in Figure 2. The concave surface is lesspronounced nearer the tip 7 oftheblade 3 as shownby the section in Figure At the same time, the blade is considerablywider nearer the tip than it is at the points near the hub. This gradual. diminishing of 55 the concavity of the-surface6 makes, the blade spoon-shaped lt; is the spoon-shaping of the blade which gives it the greater driving force. p p I r r Figure: 1 clearly shows how eachblade is '7 shaped somewhat like aspoon. The blade follows the straight line 8 shown in F igure 1 through substantially one-half of the blade length. From the point X on to the. end of the blade, I provide a slight curve indicated 7 at 9. This curve extends away from the line 8. This curve is similar to the curve of the end of a spoon. f r

Ofcourse, the face of theblade opposite the face 6 is convex as shown in Figure '4 by 30 the numeral 10. Figures 2 and 3 show how. the tips 7 of theblades3 and 4 haveslightly curved ends 11 and 12, the'curve 11 merging into the curved edge 13 of the blade, while the curve 12 merges into the curved edge 14. The outer edge 13 is slightly curved as shown in Figure 2, while the edge 14 is more abrupt-' 1y curved. It will be noted from Figure 3 that the entire lengths of the blades are curved in a clockwise direction through a small angle when looking at the rear of the propeller;

From the foregoing description of the various parts of the device, the operation thereof may be readily understood.

The direction of revolution of the propeller when viewed from the rear of the latter (see Figure 3) is counterclockwise.

During the operation of the propeller, the water is held against the concave faces 6 1.

(see Figure 3) and is kept against the faces throughout the entire contacting of the propeller with the water. The spoon shape of each blade prevents a waste of power. The gradual inwardly turning of the blade tips gives the blade vthe shape of a spoon. The I greater curve in the face of the blade near the hub and the gradual diminishing of this curve to the tip of'the blade provides a propeller that has a greater force. The pro peller has less vibration slippagedue to its particular construction. This results, of

course, in a less consumption of power which i is shown in the saving of fuel. The propeller acts in much 'the sarne manner as a screw as it forcesits way through the water. The p pe l l Qkeepst -ae oat going for-v wara in a steady course and causes: the. boat toridethe water better without drawing any moundof water at-the rear of the boat.

A lth ough I have shown and described; one

embodiment of my invention, it is to be. understood that the same is susceptible of various" changes, as may come within the scope of the invention as claimed without departing from the spirit thereof.

I claim: r Q

1, A propeller having rearwardly eXtend-. ing blades fashioned with concave leading 3 andconvex trailing faces in transverse section, these curved iaces becoming less pro nounced toward the tips 0f. the blades, and the end portions of; the blades turned in? wardly with respect'tothe blade lengths: for; P sentin el s apt d er gr pping-fl as, the propeller is revolved.

2. Apropell'er, comprising a. hub, and, blades; extending rearwardly therefrom, in diverging relationwith each other, thelead:

ing faces of the blades being fashioned con; a cave in transverse section and gradually] flattening toward the outer blade ends, and formed with inwardly turned tipswith re:

spect to thebladelengths, presenting spoons adapted for, grippingyfluid as thepropellerris revolved, 1 said, blades, when viewed ,frorn, the

rear of the propeller, being gradually curved the inner edge of the tips, turned through substantially one-eighthfof a circle V JOIDI H1 PILETL.

Images