US1854644A - Airplane propeller - Google Patents

Description

1 19, 1932- J. A. CALBY AIRPLANE PROPELLER Filed Sept. 14, 1929 Patented Apr. 19, 1932 PATENT OFFICE JAMES A. CALBY, OF MONTROSE, PENNSYLVANIA AIRPLANE PROPELLER Application filed September 14, 1929. Serial No. 392,677.

'This invention relates to propellers for airplanes, and has for one of its objects to provide a novel and simply constructed propeller of this character which shall embody 5 blades adjustable to permit their angle with respect to their path of rotation to be varied and which shall have a comparatively long pitch in any adjusted position of the blades.

The invention has for a further object to provide a propeller of the character stated which shall embody means adapted to permit its blades to be adjusted while it is in motion. a

The invention has for a further objectito provide a propeller of the character stated wherein its disc-area shall be increased as the angle of its blades is reduced and decreased as the angle of its blades is enlarged.

With the foregoing and other objects in,

view, the nature of which will appear as the description proceeds, the invention consists in the construction, combination and arrangement of parts hereinafter fully described and claimed, and illustrated in the accompanying drawings, wherein Figure 1 is a view partly in rear elevation and partly in vertical section of the propeller;

Figure 2 is a top plan view of the propeller, and

Figure 3 is a sectional view taken on the plane indicated by the line 33 of Figure 2.

Referring in detail to the drawings, 1 designates the drive shaft of an airplane, 2 and 3 the blades of the propeller and 4 the means through the medium of which the angle of the blades with respect to their path of rotation may be varied.

The blades 2 and 3 are of elongated rectangular formation in contour and are formed integrally with each other. The blades 2 and 3 are made of elastic material, such as steel or the like, and are provided centrally between their end and side edges with an opening 5 for the reception of the reduced front end portion 6 of the shaft .1. The blades 2 and 3'c0ntact at their center with the shoulder formed by reducing the front end of the shaft 1, and are secured to the shaft by said shoulder and anut 7 applied to said reduced end. The blades 2 and 3 extend rearwardly from their point of connection with the shaft 1 and are angularly related to their path of rotation, and they are held in this position against the inherent elasticity of the material from which they are made by a triangular wire stay 8.

The stay 8 is arranged at the rear sides of the blades 2 and 3, and it is connected to diagonally opposite corners of the blades by turnbuckles 9. The stay 8 is provided at its center with a hub 10, and it is secured to the hub through the medium of a plate 11, which is fixed to the rear side of the hub and has its ends bent into engagement with the wires of the stay, as at 12. g

The means for varying the angle of the blades 2 and 3 with respect to their path of rotation comprises the strut 8 and sleeve 13. The sleevel3 is loosely mounted upon the shaft 1 rearwardly of the blades 2 and 3, and the hub 10is loosely mounted upon the sleeve.

The sleeve 13 is provided at its front end with a hub retaining flange 14, and arranged between the hub and flange are antifriction members 15. The sleeve 13 is provided at its rear end with a grooved collar 15 forthe reception of the forked end of a lever 17 which when operated imparts a forward or rearward movement to the sleeve with respect to the shaft 1, and which is adapted to be operated through the medium of any suitable means, not shown, under the control of the pilot. v

The propeller is held against rotation with respect to the shaft 1 by a spline 1 the turnbuckles 9 are pivotally connected, as at 9?, to

.the stay 8, and are pivotally connected, as at 9 to the blades12 and 3. Any suitable means, not shown, may be employed to secure the turnbuckles 9 in adjustedposition. As the stay 8 extends diagonally across the ,spect to their path of rotation, and this initial angular position of the blades may be increased by moving the sleeve 13 rearwardly on the shaft 1, and the pilot may, while the scribed by said blades, said means connecting propeller is in motion, adjust the blades into their maximum angular position or into any position between their normal or minimum or maximum positions. This may be done by moving the sleeve 13 axially on the shaft 1. The rearward movement of the sleeve 13 on the shaft 1 increases the angular position of the blades 2 and 8, and the forward movement of the sleeve on the shaft permits the blades to be moved in the direction of their normal position by their inherent elasticity;

As the tips of the blades 2 and 3 move inwardly during the adjustment of the blades 7 to increase their angular position, the discarea of the propeller is decreased as the angle of the blades is enlarged, and as thetips of the blades move outwardly while the blades are being adjusted to decrease their angular position, the disc-area of the propeller is increased as the angle of the blades is reduced.- As the propeller is subjected to edgewise stress only, it possesses great strength even when of very light construction. As the propeller has a comparatively long pitch, and as the angle of its blades may be varied, it can be rotated at a comparatively rapid rate with comparatively little power.

While I have described the principle of the invention, together with the structure which I now consider the preferred embodiment thereof, it is to be understood that the struc ture shown is merely illustrative and'that such changes 'may be made, when desired, as fall within the scope of the invention as claimed.

I claim 1. A propeller comprising flexible interconnected blades, and means connecting jdia-gonally opposed portions of the blades for flexing the blades to varytheir'angul ar osition with respect to their path of rotation and coactively vary the diameter of the circle described by said blades.

2. A propeller comprising flexible blades of uniform width throughout their entire length, a drive shaft for the blades, and means longitudinally movable on the drive shaft for flexing the blades to vary their angular position with respect to their path of rotation, said means connecting diagonally opposed portions of the blades. 7

3. A propeller comprising flexible blades, a stay connected to diagonallyopposite corners of the blades to maintain them in a normal angular position with respect to their path of rotation, a driveshaft for the blades and meansloosely mounted on thedrive shaft by which the tension of the stay may befvaried to vary the angular position of the' blades and coactively vary the diameter of the circle dediagonally opposed portions of the blades.

4i. A propeller comprising flexible blades, a drive shaft for the blades, a stay connected to diagonally opposite corners of theb'lades signature.

to hold them in their normal angular position with respect to their path of rotation, a hub carried by the stay, and a longitudinally movable adjusting sleeve slidably mounted on the shaft and upon which the hub is rotatably mounted.

5. A propeller comprising flexible blades, a drive shaft for the blades, a stay connected to diagonally opposite corners of the blades to hold them in their normal angular position with respect to their path of rotation, a hub carried by the stay, a longitudinally movable adjusting sleeve slidably mounted on the shaft and upon which the hub is rotatably mounted, a flange carried by the sleeve rearwardly of the hub, antifriction elements positioned between the hub and flange, and means for longitudinally adjusting the sleeve on the shaft.

6. A propeller comprising blades adjustable to permit their angular position with respect to their path of rotation to be varied and decreasing the disc-area of the propeller as their angular position is enlarged and increasing the disc-area as their angular position is reduced, a drive shaft for the blades and means slidably mounted on the shaft for adjusting the blades and securing them in adjusted position, said means connecting diagonally opposed portions of the blades.

7. .A propeller comprising an elongated rectangular sheet of elastic metal, a drive shaft connected to said sheet, means connected to diagonally opposite corners of the sheet and adapted to bow the sheet and hold the ends of the sheet in an angular position with respect to the path of rotation of the propeller.

' 8 A propeller comprising an elongated rectangular sheet of elastic metal, and adjustable means connected to diagonally opposite corners of'the sheet and adapted to hold the ends of the sheet in an angular position with respect to the path of rotation of the propeller.

In testimony whereof I hereunto afix my JAMES A. CALBY.

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