US2422388A - Airplane propeller - Google Patents

Description

June 17, 1947.

A, w. BILLINGS AIRPLANE PI i OPELLER 2 Sheets-Sheet 1 Filed April 5, 1943 illiry JJZB INVENTOR.

June 17, 1947. A, BlL N s 2,422,388

AIRPLANE PROPELLER Filed April 5, 1945 2 SheetsJ-Shet 2 i We fl.W. BiZZi7f98 A; la a 4 M A; INVENTOR.

' hereinafter described Patented June 17, 1947 UNITED STATES PATENT OFFICE AIRPLANE PROPELLER Arthur W. Billings, Portland, Maine Application April 5, 1943, Serial No. 481,917

2 Claims. (01. 170-156) This invention relates to propeller construction, and moreparticularly to the construction of propellers designed primarily for use in connection with airplanes.

An important object of the invention is to provide a propeller which will produce the maximum propelling efficiency, using a motor of relatively low horsepower, thereby decreasing the weight of the airplane, without sacrificing power and speed.

Another important object of the invention is to provide a propeller construction which will cause a current of air produced by the rotating blades thereof, to flow around the body of the airplane or object to which the propeller is attached, thereby reducing air resistance to the minimum.

A further object of the invention is to provide a propeller which is perfectly adapted for starting and cruising speeds, insuring an unlimited range of operation.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction and claimed, it being understood that changes in the precise embodiment of the invention herein described, may be made within the scope of what is claimed, without departing from the spirit of the invention.

Referring to the drawings:

Figure l is an elevational View illustrating the forward end of an airplane fuselage, a propeller, constructed in accordance with the invention, being mounted thereon.

Figure 2 is an enlarged plan view illustrating one of the propeller blades as mounted on the supporting arm of the propeller.

Figure 8 is a sectional View taken on line 33 of Figure 2.

Figure 4 is a plan view illustrating propeller blades, constructed in accordance with the invention, as mounted on the supporting arm of the propeller.

Figure 5 is a sectional of Figure 2.

Figure 6 is a sectional View taken on line 6-5 of Figure 2.

Figure 7 is a sectional View taken on line l'--l of Figure 2.

Figure 8 is a front elevational view of the prope'ler diagrammatically illustrated.

Figure 9 is a, diagrammatic view illustrating the direction of flow of air currents produced by the propeller.

view taken on line 5-5 Referring to the drawings in detail the reference character 5 designates the propeller arm, which is mounted in the usual way at the front end of the fuselage of an airplane, the propeller arm being beveled towards the front edge thereof, to reduce air resistance to a minimum.

At each end of th propeller arm 5, is a propeller blade, the construction of which constitutes the essence of the present invention. Each of these blades is triangular in formation, the blades having downwardly curved rear portions, as clearly shown by the drawings. The rear corners of the blades are rounded, for reducing air resistance.

Each of the blades also includes a frame embodying a central stay which extends from the pointed forward end of the blade to a point intermediate the rear edge of the blade, the central stay being indicated by the reference character 8.

The frame of each blade also includes transverse stays 9 and ill that are arranged in spaced relation with respect to each other and extend from edge to edge, as shown in dotted lines in Figure 2 of the drawings.

The reference character 7 designates a curved stay which is disposed intermediate the side edges of each blade, the stay extending from the central transverse stay E2, to the rear edge of the blade. Disposed directly under the stay 1, is a channel shaped stay I l which tapers toward the rear end of the blade.

At opposite sides of the stay I, and arranged within the curved portion of each blade, are stays l i that brace the rear portions of the blades. A

' Wide transverse stay l2 forms a part of each blade, and is provided with openings to receive the securing bolts 53 that are used in securing the blades to the propeller arm. The upper surface of each blade is indicated by the reference character l4 and is constructed of suitable sheet metal material, th edges of the upper surface It being recessed to accommodate the flange iii of the lower surface N5 of the blade. The lower surface it is also formed of suitable sheet metal material and is welded to the upper surface at the point of contact between the upper and lower surfaces.

The stays as Previously described hold the upper and lower surfaces of the blades in their proper spaced relation with respect to each other.

Formed in the stay E2 of each blade, are threaded bores ll in which threaded weights are positioned to balance the propeller, should one blade be lighter in weight than the cooperating adjacent blade.

As shown by Figure 9 of the drawings, the lines A indicate the path of travel of the currents of air created by the propeller, which it will be seen, are directed away from the fuselage of the airplane, reducing air resistance to the minimum,

The path of the current of air created at the adjacent inner ends of the blades, is indicated by lines B, and it will be seen that the path of the current of air diverges away from the center of the airplane at the front end thereof.

What is claimed is:

1. An airplane propeller comprising a rotatable supporting arm, triangular blades secured to the arm adjacent to the ends of the arm, the arm having connection with the rear surfaces of the blades at points midway between the front and rear edges of the blades, and the rear portions of the impact surfaces of the blades being curve-d in the direction of rotation of the propeller.

2. An airplane propeller comprising a rotatable supporting arm, triangular blades secured to the arm adjacent to the ends thereof, one of the "cormen; of each blade being disposed forwardly, the arm being connected to the blades at points midway between the front and rear edges of the blades, the sides of the blades being parallel with the upper and lower surfaces of the arm, and

the impact surfaces of the blades being curved in the direction of rotation of the propeller, the rear corners of the blades being rounded.

ARTHUR W. BILLINGS.

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

UNITED STATES PATENTS Number Name Date 199,550 Hulbert Jan. 22, 1878 1,000,602 Jacobs Aug. 15, 1911 1,357,348 Sanford Nov. 2, 1920 1,940,318 Morse Dec. 19, 1933 2,213,497 Kelly Sept. 3, 1940 408,864 Vogelgesang Aug. 13, 1889 1,234,070 Nitschke July 17, 1917 1,423,113 I-Iolle July 18, 1922 2,243,189 Brannan May 27, 1941 68,483 Bloom Sept. 3, 1867 FOREIGN PATENTS Number Country Date 25,725 France Jan. 30, 1923 14,400 Great Britain Oct. 22, 1887 654,224 France Apr. 3, 1929

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