US1889717A - Aircraft propeller - Google Patents

Description

Nv. 29, 1932. w. F. wARFEL i AIRCRAFT PROPELLE Filed Sept. 22, 1930 ATTORNEY Patented Nov. 29, 1932 WILLIAM F. WARFEL, OF WENDLING, REGON AmonAr'r rnoPELER Application filed September 22, 1930. Serial No. 483,651.

My present invention has reference to an improved propeller which is primarily desgned for use in connection with aerial navigation but which may be also employed for water navigation, and my object is an im-v proved construction of propellers in which provision made for obtaininga better grip on the fluid medium through which the vehicle is beinggpropelled.

Another and important object is the provision of a propeller having front and rear blades which extend radially from the hub in diametrically opposed directions, the said pairs of blades being slightly offset With respect to each other, both sets of blades being slightly rounded from their connection with the h'ub to their tips and their said tips rounded inwardly, both pairs of blades having their outerfaces convex and their inner faces concaved and the inner pair of blades being reduced to their connection With the hub so that both sets of blades,'in the operation thereof will act against a tangible fluid surface and also relieving the body of the craft of the force of fluid which is otherwise directed thereagainst.

To the attainment of the foregoing the invention consists in the improvcment hereinafter described and definitely claimed.

In the drawing:

Figure l is a side elevation of a propeller in accordance with this invention.

Figure 2 is a front elevation thereof,

Figure 3-is a sectional view approximately on the line 3-3 of Figure 1.

The hub 1 on the propeller merges into a bullet-shaped outer end 2 and the hub 1 is connected to the propeller shaft 3 for the aircraft or ship.

There is integrally formed on thehub 1 a pair of oppositelv directed laterally extending rear blades 2' and a pair of laterally extending front blades 3' The blades are suitably spaced from each other. The front blades 3' are of a less length than the rear blades 2' and the blades 2' and 3' are slightly offset from each other, although thel major portions of the width of the blades 3' is disposed over the blades 2'. The outer blades 53 3' are substantially of an eq'ual width throughout and are slightly curved from their juncture With the hub to their ends and their said ends are slightly Curved inwardly as at 4. The outer faces of the blades 3' are cross sectionally yrounded or are convexed, while the 55 inner faces of the blades from their tips 4' to their juncture with the hub 1 are dished .or concaved, as at 5. The edges and tips of the blades 3 are sharpened or feathered.

The inner blades 2', at their juncture with the hub are for a suitable distance reduced 'in width, as indicated in the drawing by the numeral A(i and from thence the said blades are gradually widened outwardly so that the active portions of the blades are of a slightly greater width than that of the blades 3'. The outer or active portions 7 of the blades 3' are substantially spoon-shaped, that is, the outer faces thereof are convexed, as at 8, and the inner faces thereof are concaved, as at 9, the concavities being extended from the outer ends or tips of the blades to their juncture with the reduced connecting portions 6 thereof with the hub 1. The parts 6 are round in cross section.

A propeller constructed in vaccordance with my invention reduces vibration as there is a steady running of the propeller. Each of the inner and outer pairs of blades act independently upon the fluid surface, as the outer 30 blades have a tendency'to cut through the fluid and the inner vblades likewise cut through the fluid. The Cutting action, however, contacts with the tangible fluid surface. The reduced inner ends 6 of the blades 7 relieve air pressure next to the hub, which is impossible with ordinary propeller constructions while the tips 4' of the outer propellers tend to force the fluid rearwardly therefrom against the convex faces of the inner propellers.

As disclo'sed by the drawing the pairs of bla-des 2' and 3' are respectively arranged at a slight angle with respect to each other, so that the trailing edges of the said 'blades are spaced a greater distance from each other than are their leading edges. This afi'ords a pocket for trapping the fluid in its passage between the blades which causes the said blades to act on a tangible fluid surface when the propeller is in operation.

It is to be understood that the details herein described and illustrated are for the purpose of explaining the nature of my invention and are to be interpreted as illustrative and not in a limiting Sense.

Having described the invention, I claim:

A propeller of the type described, comprising a hub having a pointed nose, and having spaced pairs of extending front and `rear blades, and which pairs of front and rear blades are arranged at angles with respect to each other so that the trailing edges of the blades are spaced a greater distanoe away from each other` than are the leading edges of the blades, the front blades being of an equal width throughout and having their trailing edges, adjacent to their outer ends,

. Curved toward their tips, and said tips being rounded and the inner faces of the said outer blades being dished throughout the length thereof, the inner blades being of a greater length than that of the outer blades, and having reduced cross sectionally rounded portions at their juncture with the hub and from said rounded portions being substantially spoon-shaped and the concaved inner faces of the said inner blades terminating at the juncture of the rounded and spoon-shaped portioneI of said blades.

In testimony wheref I afix my signature WILLIAM F. WARFEL.

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