US2213497A - Airplane propeller - Google Patents

Description

pt. 3. 1940- w. H. KELLY 2,213,497

AIRPLANE PROPELLER Original Filed June 21, 1938 2 Sheets-Sheet 1 INVENTOR.

l V/LL/AM b. flaz ATTORNEY.

Sept. 3, 1940. w. H. KELLY AIRPLANE PROPELLER Original Filed June 21, 1938 2 Sheets-Sheet 2 INVENTOR. LIAM H /fLL y.

Patented Sept. 3, 1940 UNITED STATES AIRPLANE PROPELLER William H. Kelly, Denver, 0010.

Application June 21,

1938, Serial No. 214,887

Renewed December 22, 1939 Claims.

pulsion and prevent the air from being thrown centrifugally outward.

The basic idea is to design a propeller which will have circumferentially extending channels with side walls sufficiently deep to prevent the air from escaping radially or centrifugally from the blades so that all of the air will be projected rearwardly in a solid, powerful, propelling stream.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the drawings and throughout the description.

In the drawings:

Fig. 1 illustrates one embodiment of the invention.

Fig. 2 is a section therethrough taken on the line 2-2, Fig. 1.

Fig. 3 is a similar section illustrating the sam construction with a greater pitch.

Fig. 4 is a similar section illustrating a still greater pitch.

Fig. 5 is an alternate form of the construc- 40 tion of Fig. 1, in which the propelling cups are circumferentially curved.

Fig. 6 is a plan view of the form of Fig. 5.

Figs. '7, 8, and 9 illustrate various adaptations of the principle of the invention.

Fig. 10 is a face view of a propeller in which the preferred form of the invention is embodied.

Fig. 11 is a rear View of the propeller, of Fig. 10.

50 Figs. 12, 13, 14, 15, and 16 are blade sections of the form of Fig. 10, taken on the lines corresponding to their respective figure numbers.

The highly-efficient effects of this propeller are obtained from the use of curved air-cups 55 mounted torotate about an axis and opening in the direction of rotary travel and at their rearward faces. In Fig. 1, two such cups are illustrated at I 1 mounted on the extremities of radial arms I8 projecting from a hub I9. The cups I! are scoop-shaped and completely curve-linear, as shown in Fig. 2 so that a line drawn on their surfaces at any point will be a curved line. The arms I8 pass completely through the cups to form a substantial, balanced support therefor. This relieves the cups of structural stress and allows them to be formed of relatively thin, light, material. All of the stresses are absorbed by the arms I8.

A streamlined shell or vane 20 surrounds the arm l8 where it crosses the cup to prevent the arm from creating air resistance within the cup. The streamlined shell 20 is loosely mounted on the arm so that it 'may rotate to a position in the plane of least resistance in the air stream and, because of its shape, it presents very little if any resistance to the flow of the air. When the propeller is not rotating, the vanes 20 hang vertically downward but when the propeller is rotated, the vanes 20 immediately assume their most eflicient position. v

The curvature of the cups l'l may be designed to produce any desired pitch, as shown in Figs. 2, 3, and 4 by the broken arrows.

Fig. 5 illustrates the same principle in another form. In this form, however, the inner faces of the cups are flattened, as shown at 2|, and

curved upon a circumference around the hub so as to reduce any turbulence caused by the trailing edges thereof.

Figs. '7, 8, and 9 show quarter-spherical cups mounted in various positions relative to the hub. The cups of Figs. 7 and 8 are inclined to offset the centrifugal or outward effect of the air and are designed to throw it in a compact rearward air stream. Fig. 9 illustrates the same principle with the cups mounted at the hub without supporting arms.

In Fig. 10, the cups or pockets are embodied in a radially extending propeller blade. The blades each consist of a curved outer shell 22 which is divided throughout its length by means of lateral partition plates 23; closed at its outer extremity by means of an end plate 24; and at its inner extremity by an inner end plate 25. The blades are supported upon tapered, tubular arms 26 which extend radially outward from a hubmember 21 throughout the entire length of the blade. The arms extend through, and are secured to, eachof the partition plates 23. The plates 23 separate the blade length into curved pockets having cross sections of the forms indicated in Figs. 12 to 16.

In each pocket, a stream-lined shell or vane 28 is mounted on the arm 26 and is free to rotate thereon so as to automatically resume the most effective position for streamlining the arms 26.

While specific forms of the improvement have been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent 1. A propeller constriction comprising: a hub; arms extending radially outward from said hub; scoop-shaped cups mounted on said arms, said cups being open in the direction of rotation and at their rearward faces so as to receive a stream of air, curve it, and expel it rearwardly, said arms extending across said cups to support the latter; and stream-lined vanes formed on said arms within said cups.

2. A blade construction for propellers comprising: a hub member; a blade arm extending radially outward from said hub member; a curved propeller shell positioned to receive a stream of air from the direction of rotation and discharge it rearwardly; and a series of lateral, intermediate partition plates within said shell, said arm passing through all of said plates to act as a support for said shell.

3. A blade construction for propellers comprising: a hub member; a blade arm extending radially outward from said hub member; a curved propeller shell positioned to receive a stream of air from the direction of rotation and discharge it rearwardly; a series of lateral, intermediate partition plates within said shell,

said arm passing through all of said plates to act as a support for said shell; and stream-lined shield members hanging loosely on said arms between each pair of said partition plates, said shell being inclined with reference to said blade arm so asto gradually approach the latter as the distance from the axis is increased.

4. A blade construction for propellers comprising: a hub member; arms extending radially outward from said hub member; transversely curved propeller shells mounted on said arms, said shells having the largest cross-sectional area near the said hub member and tapering gradually toward the outer end where the crosssection area is comparatively small.

5. A blade construction for propellers comprising: a hub member; scoop-shaped cups mounted radially outward on said hub member, said cups being open in the direction of rotation and at their rearward faces so as to receive a stream of air, curve it, and expel it rearwardly, said cups being completely curvated so that any line on their inner or outer surfaces will be a curved line.

' WILLIAM H. KELLY.

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