US1867809A - Propeller assembly for airships - Google Patents

Description

y 19,1932. H. L. HAsE 1,867,809

PROPELLER ASSEMBLY FOR AIRSHIPS Filed Sept. 9 1930 2 Sheets-Sheet l INVENTO July 19, 1932. H. L, CHA E v 1,867,809

PROPE LLER ASSEMBLY FOR AIRSHIPS Filed Sept. 9, 1930 2 Sheets-Sheet 2 ll W ENTOR WW1. 6M"

J26. 25%ATT0RNE Patented July 19, 1932 PATENT OFFICE HERBERT I. CHASE, 01 DENVER, COLORADO PROIPELLER ASSEMBLY FOR AIRSHIPS 7 Application filed September 9, 1930. Serial No. 480,702.

My invention relates to improvements in propeller assembly for airships.

' The primary object of the invention is to provide an improved form of propeller and an annular surrounding member or cowl therefor, whereby all air acted upon by the ropeller is drawn thereby directly from the ront, thuscontributing to the highest efficiency of the propeller.

Further, to provide an improved form of propeller for air ships having wing members which. are so constructed that in operation they create a vacuum at the front side of the propeller, the resultant air suction causing the air to compress at the rear of the propeller and a surrounding annular cowl which extends beyond both sides of the propeller, its rear end being flared from a point substantially' coincident with the rear side of the propeller; whereby the expanding action of the said compressed air against the said flared surface of the cowl, acts in conjunction with the thrust of the rear faces of the wings against the said body of compressed air in propelling the ship.

Further to provide a substantially S- shaped propeller comprising a hub and opposite wings, the tip portions of which are concentric w1th the axis of the propeller, the cross sectional contours of said wings on lines concentric with the axis of the propeller, being in the form of compound curves, and their front faces being concaved; the perimeters of said wings being tapered to form thin resilient blade-like portions which can move inward where the speed of the propeller is sufficient to create a vacuum in the concaved faces of the wings, or outward when the centrifugal force is greater than the force created by the vacuum, thus permitting an automatic adjustment of the blade-like portions of the wings under varying speeds of the propeller.- These objects are accomplished by the mechanism illustrated in the accompanying. drawings in which:

Fig. 1 is a front view of the improved propeller.

Fig. 2 is a rear view of the same. Fig. 3 is a sectional view thereof, on the line 33 of Fig. 1. v

Fig. 4i is an end view of the propeller.

Fig. 5 is a sectional view on the line 5-5 Of Fig. 1.

Fig. 6 is a side view of the forward portion of an airship equipped with the improved propeller, which is surroundedbya cowl which forms a cooperative part of my invention, the cowl being in section.

Fig. 7 is a side view of the cowl and Fig. 8 is a front view of the cowl and propeller.

In normal flight an airship is pulled along by the thrust of the propeller and in the 5 present case the propeller thrust is augmented by the expanding action of the air against the flared wall of the rear end of the cowl, as the air is drawn through the cowl by the suction action of the propeller as will hereinafter be fully described.

Referring to the accompanying drawings:

The letter A designates the forward portion of an airship, B the improved propeller, and C the cowl which surrounds the propeller.

The improved propeller is substantially in the form of an elongated S and comprises a hub 1 and oppositely extending outwardly curved wings 2, the tip portions of which .are concentric with the axis of the propeller.

Each wing, from its forward or advancing edge to its rear edge is of the cross sectional outline shown in Fig. 5 or is in the form of a compound curve, and the marginal edge or perimeter of each wing is curved or rolled on its rear side, from the point of its connection with the hub to about the point 4, from which point to. the tip, it merges into a flat face as shown at 5. The front faces. of 00 v thin resilient blade-like member 8 or if desired, this blade-like portion may be a thin v resilient strip which is secured to the perimeter of the wing.

The blade ortions in either case are thin enough to e resilient,

' for a purpose to be hereinafter explained,

and the tips of the blades extend slightly beyond the rear edges of the wings, as shown at 9. I

The propeller may be secured to its driving shaft in any suitable manner, and it is surrounded by a cowl C which is arranged and constructed in the following manner:

, The cowl is in the form of a band or ring, the outer face of which tapers toward its rear rim at any angle which may prove most effective, while its inner face is preferably bell-shaped for about two-thirds of its length, as shown at 10, from which point it flares to its rear rim, as shown at 11. The front rim of the cowl extends slightly beyond the front face of the propeller and the rear face of the propeller extends-slightly beyond the point where bell-shaped surface of the cowl merges into the flared surface, as clearly shown in Fig. 6 and there is only a slight space between the tips of the propeller and the wall of the cowl at this point. The cowl may be secured to the airship in any suitable manner, as by strap irons-12, which are secured to the cowl and to the forward end portion of the ship.

By surrounding the propeller with the cow air approach to the propeller can only be directly from the front, the air being cut off in all other directions. The rapid rotation of the propeller creates a vacuum withinthe concaved faces ofthe wings, and the resultant suction force draws the air into the propeller 1n a stream, which-is confined and limlted by the cowl, and as this'air is forcibly ejected rearwardly, it forms a compressed body back of the propeller andas this compressed body of air expands against the flared face of the cowl, it naturally exerts a for'-. ward thrust against the cowl, which is in addition to the thrust of the rear faces of the propeller wings against the said body of compressed air, and thus the ship is carried forward under the direct suction force from the front, and the thrust of'the pro eller, plus the expanding action of a body 0 compreslsed air against the flared face of the cow a The construction of the improved propeller is such that rapid rotation creates a vacuum in the concaved faces of the wings, causing a powerful air suctionthroughthe propeller and the wings move so rapidly away from peller.

the in-rushing air, that they offer no impediment to the same. By surrounding the pro-. peller with the improved cowl, all of the radial force exerted by the suction of the propeller is converted into direct suction force from the front. The resiliency of the tip portions of'the wings permits of their lateral movement under varying speeds, of the propeller, so that they adjust themselves automatically according to the speedof the propeller and it has been found after repeated tests that the propeller has greater lifting power when the tip portions are thinned to a resilient condition than when they are rigid and it'has also been found that the improved propeller develops far more power per square foot of surface within the circumference of the propeller at any given rate of speed than is developed by the usual type of propeller at Y Having described my invention, what I I claim as new and desire to secure by Letters Patent, is:

1. A propeller of the character described which is substantially S-shaped andv comprises a hub and oppositely extending wings, said Wings being in the form of compound curves in cross section, and being concaved on their front faces, the concavities disappearing near their advancing edges; the perime- I ters of said wings being rolled on their rear sides and tapered to thin resilient blades.

2. A propeller of the character-described which is substantially S-shaped and comprises a hub and oppositely extending wings, each of said wings being in the form of a compound curve in cross sectiontaken on a l1ne concentric with the axis of the propeller,

and being concavedon its front face, the concave disappearing near its advancing edge;.

the perimeter of the wing being rolled on its rear side and tapered to a thin resilient blade, the tip of which extends beyond the rear edge of the wing.

3. A propeller of the character described, which is substantially S-shaped and comprises a hub and oppositely extending wings each of which is in the form of a compound curve in cross section taken on a line concentric with the axis of the propeller, and is concaved on its front face from its perimeter to the hub, the bottomof said concavity being substantially semi-circular in radial section, the perimeter of the wing being curved transversely on its rear side to correspond with the curvature on its front side, said perimeter being concaved on their front faces,- and being in the form of compound curves on lines concentric with the a'xis of the propeller, said concavities disappearing near the advancin edges of the Wings, the advancing edges 0 the propeller wings being curved tangentially to the axis of the propeller beginning at the hub and gradually merging into concentric curves near their tips, the concentric portions of the Wings being tapered to thin resilient blades.

In testimony whereof, I aflix my signature.

HERBERT L.

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