US1692397A - Helicopter - Google Patents

Description

Nov. 20, 1928.

R. wAGNER.

HELICOPTER Filed' oct. 10, 1925 wys.

' mental Nv. 20;,1928.

UNITED sTATEs PATENT OFFICE.

BIUDI'ZE' WAGNER, OF HAMBUBG, GERMANY.

' HELICOPTER.

Application filed October 10, 1925, Serial No 61,723, and in Germany .Tune 10, 1922.

The present invention deals with helicopters and provides an arrangement which increases the reliability, simplifies the construction, increases the eiiiciency, and lessens' the cost 'of production, of such devices.

In the usual form of helicopter, the effect of the turning moment o f the power plant on the machine is taken up or compensated by the use, in general, of two or more counter-running propellers arraned either coaxially one above the other o`r si axes, such propellers being positively inter'- comiected in order as far as possible to produce similar and equal working or lifting forces for each propeller. In such constructions, however, there is much danger that when one propeller becomes inoperative, the entire machine is set in circular movement. This of course, results in the propeller still in operation generating insuflicient lifting force to sustain the apparatus. Aside from this danger, a construction wherein propeller sh'afts penetrate each other presents certain constructional difliculties.

In the present invention for the purpose of simplifying the construction and increasing the securit o f operation of these devices, use

is made o but a single revolving propeller. The turnin moment of the engine in this case is equalize by a stationary, so-called counterpropeller mounted below the main propeller Vand having curved or bendable blades.

This counterplrcpeller takes up or compensates without s ock, the greater part of the swirl of the main propeller stream which has arisen as a reaction of the rotation of the main propeller, and directs and carries oif the air streams in an axially downward direction.

With a construction as contemplated byv this invention a rotation of the body on its Vertical axis is prevented and at. the same time' an additional lifting force is produced whereby the efliciency of the drive is very substantially increased. The additional lifting forceis a result of the changing of direction of the air streams comin from the main pro-I peller, by coactingv Wit the blades of the counterpropeller. 'v ,w The arrangement .of stationary counterpropeller blades according to this invention provides an additional advantage in that the entire apparatus is stabilized in the direction of Vertical movement and furthermore, the blades may serve, even though somewhat ime by side with parallel.l

perfectly, as gliding surfaces for a gliding flight of the craft in the event the power plant should break down.

Thus with the contemplated construction greater security is provided as compared with other constructions wherein such gl''ding surfaces are wholly absent.

The invention can also be applied to aircraft having several adjacently positioned supporting propellers wherein each propeller has its `own counterpropeller and any desired direction of rotation. As compared with other constructions the advantage' of the present form consists in that the swirl of the air stream from each individual supporting propeller is neutralized by its own counterpropeller so that no free turning moment can arise should one of the supporting propellers cease to properly function. y

In order to equahze or compensate for any residual turning moment on the body of the device, accordin to this invention, the counterpropeller blaes,'either wholly or in part, may have all or a part of their blade surface arranged to swing about -a horizontal axis. This mobility of the blades can serve to produce a certain inclined position of the Verticall 'axis of the aircraft, and thereby a lateral w movement Of the craft in 'any desired direction.

The number of counterpropeller blades aci cording to the present invention is not limited drawings wherein like reference characters. designate like parts throughout, and where- Fig. 1 is an elevatlional view of the entire craft partly shown in section. i

' Fig. 2 is a top plan view of the craft .With parts broken away.A i

Fig. 3 is a section on line 3-78 of Fig. 1. With reference to thedrawings a helicopter is shown wherein. a light weight high pressure steam vturbine is used for the drive..

i It is of course immaterial as regards this ini cro'ssed blades.

vention just what particular type of power plant is used. However, as compared wlth an internal combustion engine drive, this particular drive is of advantage in that the tur-` several lifting propellers are arranged on a very large craft. In such craft, for example,

the boiler with the auxiliary engines can be placed in a central main body, while each lifting propeller can be driven by a separate turbine, so that except for the propellers lying outside of the center, only a small part of the weight of the power plant is ,situated away from the center.

In the figures of drawing the body 1 of the aircraft serves as the hub or attaching 'means for the counterpropeller 2 which in the present case, as shown in Figure 2, has four Th'e main or lifting propeller 3 is shown as having two blades and as having a hub 3' fitting onto a pivot or sup- `porting member 4 projecting from the body 1 and carried thereon by roller bearings 5. A drive shaft 6 for the main propeller is repceived centrally by the member 4 and is connected to the main propeller by means of a plate 7 and a nut 6'. The connecting means just described is enclosed by means of a' cap which fastens over'the hub 3' and gives a smooth outline.

The hub and cap are made sulficiently large so that they form, together with the body 1,, a

stream line contour'whereby the air is caused to flow from one 'end .to the other in an eflicient manner.. Due to this construction the counterpropeller 2 is capable of utilizing the p core of the swirl from the main propeller in a snbstantially complete manner which results in the greatest possible increase of thrust.v

The relative curvature of the counterpropeller blades 2 with respect to the'main pro-' peller, and the curvature of the main proi. peller blades, is clearly shown in the sectional view of Figure 3.

The main propeller canbe made hollovitand' is preferably formed of duralumin and is 'co'` structed in accordance with approved practice- *in the formation of the usualair propellers. The main propeler is driven by the shaft 6: which is supported'throughout its length in.

the member 4 and,hence, is subject only to torsional 'strain', and is ,entirely free from bending stresses.

The gearing of 4the turbine is designated at 8 while two turbines 9, 9 are provided for greater security.L An air cooled condenser 10 in the form of a pipe system encompasses the entire body 1 between the blades 2 and re- 'c'eives'the steam from the turbine by way of the chambers. 11 formed within the blades 2. The air from the main propeller passes through this pipe system on its way. to the lower end of the craft.

It is of course possible to use other typesz of conde-nsers but the one described is very suitable.

The steam generator 12 is situated in the body 1 and is suitably provided with a superheater, air preheater, and if desire-d, a feed water preheater. An operatorls platform 13 is provided in the body 1 together with other necessary accessories which it is. not necessary to show Below thel platform 13 is a pilot cabin 14 which is located under the engine room, and from which the vblades of the counterpropeller 2, having a construction to be described, can be operated.

As shown in Figure 1 the lower portion of I each of the blades of the counterpropeller is hinged to the upper portion as at 15' so as to swing about horizontal axles 15".

Instead of having only a part of each of the counterpropeller blades movable, under certain conditions the entire blade may be rotatable as a whole on the body 1, in order to vary its position relative to the ofl-flow from the propeller stream.

Asv shown in the drawings the counterpropeller blades at their outer ends, are provided with enlarged portions 16 to the lower ends of which are attached air buflers 17 used for landing on solid ground. Thebody 1 as shown is also provided with a similar air bufi'er 18l for landing on solid ground.

In order to make the craft of more general i use and to safeguard it in operation, the members 16 are provided `with water-tight floats 19 so as to permit alighting on and arising from water surfaces. The positionl of thev floats 19, remote from the center of the craft, provides great stability against tipping, and

-when resting on a'water'surface the water level would be as indicated by the line W. L.

in 'Figure 1. v ;In addition to'the embodiment of the invention as shown, and described above it is of course possible to use many other types and arrangenr'ients'of` drive and other forms and numbers of bladesandcontrol surfaces without exceeding the contemplated scope of the invention.

Furthermore, under certaincircumstances in order to provide for lateral movement of the craft, use can be made of auxiliary drive propellers having horizontal axes. 1

Again, when desired, the blades offthe,

counterpropeller can be interconnected at their outer ends by a circular collar for reinforcing the same.

Having now described a complete embodiment of my invention I now claim:

1. A helicopter comprising a main rotatable propeller and a stationary counter-pro-- peller with curved blades mounted immediately below the main propeller for taking up and neutralizing the swirl of the fluid stream from the main propeller.

2. A helicopter comprising at least one -main rotatable propeller, a stationary counter-propeller with ourved blades mounted immediately below the main propeller for taking up and neutralizing the swirl of the fluid stream from the main prope'ller, and a chambered hub for the oounter-propeller constituting the body of the helicopter. V

3. A helicopter comprising at least one man'rotatable propeller, and a stationary counter-propeller with curved blades munted immediatel below the main propeller for taking upandyneutralizing the swlrl of the fluid stream from the main ropeller, the counter-propeller havin four lades spaced with equal angularity a out said helicopter.

4. A helicopter comprisin at least one main rotatable propeller an a stationary counter-propeller with curved blades mounted immediately below the main propeller for taking up and neutralizng the swirl of the 4fluid stream from the main propeller, said counter-propeller having supporting members extending downwardly from the blade ends, said blades being formed with hinged portions terminating above thelower ends of said supporting members.

. 5. A helicopter eomprising` at least* one RUDOLF WAGNER.

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