US2220658A - Propelling means for aircraft - Google Patents

Description

Nov. 5, 1940.

A. M. OSTROWSKI ETAL PROPELLING MEANS FOR AIRCRAFT Fil ed Jiine 9, 1939 FEED M aszeomsw/i By 69% osreamsxli INVENTORS,

Patented Nov. 5, 1940 PROPELLING MEAN FOR AIRCRAFT Alfred M. Ostrowski and Caroline. Ostrowski,

Hamtramck, Mich.

Application June 9, 1939, Serial No. 278,302

i'ciaim.

The purpose of the invention is to provide a propeller of higher efficiency, in which, by the expenditure of no larger quantity of power than is ordinarily used, more satisfactory results and higher speed can be obtained. It is well known that when an aircraft goes through the air propelled or pushed forward by the ordinary propellers, the greatest pulling or pushing force is exerted by those parts of the blades of the propeller, which are quite distant from the hub. Putting it reversely, it is known that the propelling power of a conventional propeller near the hub is very low. It is also known that when an airplane is proceeding through the air, the air right in front of the hub of the propeller is compacted or compressed so as to impede theprogress of the aircraft travelling through the air. The purpose of our invention, therefore, is to accomplish two purposes: (1) To increase the efiiciency of the propeller, that is, to bring itvised the novel form of propelling means comprising our invention, which will be described with reference to the accompanying drawing, in

whichi I Fig. 1 shows a side view of our improved propeller as mounted at the front of an airplane.

Fig. 2 shows the side view of said propeller with some modifications.

Fig. 3 shows the front or end view of said propeller.

Fig. 4 shows a fragmentary view of a mounting of the hub of our propeller.

Similar numerals refer to similar parts throughout the several views.

The propelling means of our invention comprise combination of a conventional propeller with a spiral plane extending in a helical formation in front of said conventional propeller. Numeral Ill indicates a shaft on which the propeller and our spiral plane is mounted. II is a hub of said propeller. Numeral indicates a socket threaded reversely, by means of which the propeller is secured to shaft I0, while numeral l9 indicates a lock nut by which the propeller, once set upon the shaft, is retained in its operative position. Numeral l2 indicates the blades of the propeller. Atthis point we wish to remark that while we are showing in our illustrations a two-bladed propeller, a propeller of three or more blades may be equally well used as an element in members.

the combination of propelling means shown by us. Extending from hub II and forming an extension of the shaft I0, is an auxiliary shaft l3, which may be integrally connected to the hub II or which may be made separate therefrom, as shown in Fig. 2. Said auxiliary shaft is quite thick at the hub, but tapers towards its free end. Winding around said auxiliary shaft l3, but at some distance away from it, is a spiral plane l4.

This ought to be made preferably of cast metal 10 or some synthetic material, such as Bakelite or Micarta, so that said plane may have a high degree of rigidity without easily being subject to vibration. One of the ends of said plane, the

broad one, is attached to a blade of the propeller substantially to the leading edge of said blade and to the middle section thereof, the width of the spiral plane where it joins the blade of the propeller being about one-third of the length of said blade. Were the length of the propeller divided into three equal parts, the line of junction between the spiral plane and the blade of the propeller would occupy the middle section of said plane. As to the manner of junction between said propeller and the plane, a union of these two elements might be accomplished by welding in case where the parts are made of metal, or said plane might be secured to the blade by screws or bolts, as shown in Fig. 2, while in the case where the propelling means are made of some synthetic material, the propelling means shown by us might be molded as one unit.

Proceeding from said blade to the free end of the auxiliary shaft l3, said spiral plane tapers in width and forms somewhat more than two full convolutions around said auxiliary shaft but at a distance therefrom so that air may freely pass around said auxiliary shaft, that is, between the shaft and the inner edges of said spiral plane. At its narrower end, said plane I4 forms an annular member 2I fitting over the end of the shaft l3 and close to the end disc l5, to which said annular member is secured by means of screws or bolts Hi. It might be desirable, in order to reduce the vibration of said spiral plane M, to reenforce said plane by means of some stabilizing This has been accomplished in this case by struts or braces, which are indicated by numerals I! and I8. When in place and seen from the side, the proportion of the plane to the blades of the propeller is such that straight lines drawn from the tips of the propellers to'the tip of the free end of auxiliary shaft l3 will form substantially two' sides of an equilateral triangle,

of which the line joining the tips of the propeller is the base.

A minor variation of the structure in Fig. l is shown in Fig. 2. In this case, it will be seen that our spiral plane 28. supported on auxiliary shaft 21, is attached to blade 34 of the propeller by screws 35. In order that vibration be minimized. convolutions of our spiral plane 28 are bound together by guy wires 29 and 30. The mounting of the propeller, following more conventional lines, comprises a flange 23 on motor shaft 22, ahollowed hub 24, provided with holes so that screws 26 may be inserted through said hub reaching Auxiliary shaft 2'! is also provided with a flange 25 and it is by means of said screws 26 that hub 24 is held between said two flanges 23 and 25. This construction allows the spiral plane with the auxiliary shaft 2! to be detached from hub of the propeller, shown in Fig. 2.

In practice, this combination of a conventional propeller with our helically-formed spiral plane accomplishes some very useful results. As stated above, the air right in front of the progressing plane is condensed. Such being the case. the blade of our spiral plane cutting in a screw action through said condensed air results in a substantial forward thrust without, however, impeding or interfering with the state of air right in front of the outer tips of the propeller. Owing to the tapering width of the plane, and such a construction that no part of one convolution overlaps the succeeding convolution, said spiral plane revolves in air which is entirely unspent but which would be of no particular value in securing traction by the blades of the propeller. The free spaces between the auxiliary shaft, on which the plane is mounted and around which said plane revolves. allow free passages to air between said auxiliary shaft and said plane, thus minimizing resistance which otherwise would be offered by air compact ed in front of said blade and said propeller.

We believe this construction to be novel, useful and efficient. It will be obvious. however. that modifications may be made from the precise construction shown without departing from the spirit of our invention. What we wish to claim is as follows:

Propelling means for aircraft comprising a hub adapted to be mounted upon a drive shaft. an auxiliary shaft extending forwardly from said hub in axial alignment therewith, blades carried by the hub and extending radially therefrom, an auxiliary screw consisting of a strip extending spirally about the auxiliary shaft in radial spaced relation thereto with its convolutions gradually reduced in external diameter towards the front end of the auxiliary shaft, the rear end of said strip being fixed to the front face of one blade midway the width and the length of the blade. with the width of the strip disposed longitudinally of the blade. a collar at the front end of said strip fitting about the front end of the auxiliary shaft, fastening means carried by the front end of the auxiliary'shaft for firmly securing the collar in place thereon, and bracing rods extend- 1

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