US1687636A - Aeronautical propeller - Google Patents

Description

0a. 16, 1928. S. A. REEDv AERONAUTICAL PROPE'LLER Filed May, 12, 1924 ATTORNEY j f QIBWE TOR OZ v Patented Oct. 16, 1 928.

; UNITED STATES PATE O F SYLVANUS A; REED,',OF new YORK, iv. Y.,' Assreivon TO THE REED rRornLLnR o0. me, on NEW YORK, n. Y., A CORPORATION or NEW Y R -j .AERONAU TIQAL PROPELLER.

Application. w ma '12,

cation for patent, filled June 22, 1922, Serial No. 570,139, I disclose-certain types of metal 5 aeronautical propellers, and my present im#.

shaft-hole bored through the propeller, boltprovements are also applicable tosaid gen-'- eral types, but,'of course, are not in any Way limited thereto.- f t My present invention includes ii-simplificationof structure whereby omitting ,the'

featuresneeded for interchangeabilitywith customary wooden propellers on the same steel hubs a propeller may. be Obtained of greater efficiency and strength with less ag-, gregate weight. In some of my earlier forms of structure, the above mentioned-adaptabilityfor attachmerit to existing steelhubs employed a cen tralexpansion ,to permit ma ing a large central hole to pass the end of the driving-shaft and smaller holes for thevhub-bolts; In my present improvements, there is no central holes are reduced in number and long bolts are dispensed with. But more particularly. I-

gain inthe total efiiciency, because of-a'closer approximation which I am able to obtain to a true helix nearly up to. the drive shaft-itself. I'also gain the propulsive effect ofjthe blades up to those points and inaddition I- r gain by the omission of a central boss which" is an obstruction to flight, is anadditional weight andabsorbs a certain amount of the driving power. p A true helical propeller passes'through the driving axis in such a manner thatthe driving or thrust face is-at a pitch-angleof 90?, and that'type of section of a helical surface which constitutes an ideal propeller will'be found to have around the-longitudinal or di ametrical axis of the propellen-a continuous twist, always in the same direction, right or left-handed, from one tip'through the driveshaft axis to the other tip. In my said patent and patent application, in order to -ac commodate the central shaft-hole andcustomary huh, I reversed this twist near the central region or hub and resumed the original twist beyond. In my present improvements I have a continuous twist in one direction from tip to tip of the'blades,

No.:"1,463,5 56,'"dated July 31, 1923, and also in my pending app li- 1924. Seria1No.712,tl 16.

I It isfobvious soform-a propeller by twisting a; ,sing-leflpieee of elongated metal plate and teprevide the same with the usual camber faceforward-and a flat face on thethrust side,the plate before twisting, as above described, will have the saidchamber 0f one'blade on one side of the original plate and'thecamberof the otherblade on the reverse side of the plate, Them-after twist,

tothe appropriate pitch, always in one direction, both-camber faces will be found on the same side namely, the forward: side of.

theftwisted propeller. a i l In order to secure the propeller to ICE.

t the driveshaftforsafe transmission oftorque and thrust several means, are available with the ,pec'uliar construction and arrangement. of

this propeller, butI prefer, where possible, to omit the usual'drive-shaft extension'and to terminate. the driveshaft closeto its for ward bearing and secure thereto a metal body or shell, preferably of steel, with inclined side-slots, to receive andhold securely the propeller blades in position, said shell having a medial re-inforcing ring or strap, pref- .erably of steel, passing through holes in the propeller and; assisting in looking it securely in'place. a With these and other objects in view, my

inventionswill be'more fully described, illustrated in the drawings and then particularly pointed out in the claims.

r In the said drawings anddrive-shaft, with the attaching body or shell and its adjuncts in longitudinal section. t Fig. 2, is an underside view of the propeller Fig. 1, is'a side elevation of the propeller and its shaft-attaching means, with the shaft I omitted. v v t Fig. 3,-is a side elevation of the structure,

the view being at right-angles to that shown in Fig. 1.f.

Referring to the drawings '1 is a portion. of the outer end-of the propeller drive-shaft, and 2 is a flange on the end thereof. The

a central connecting part 5, which contains or includes, indicated .by the line 77, the

axis ofthe propeller shaft, the arrow 6, showboss near the central region, as in the case of 100 propeller is formed with blades 3 and 4, with wooden propellers, or of being reversed intwist asin the case of certain forms of my metal propeller requiring a central shafthole,

my improvedpropeller-blades continue toinj crease their pitch-anglesso that at the point 7, at'the axial line, they are at 90, and it is notedjthat'the direction of the twist around the longitudinal axis, indicated by the line 8.8 isinxone direction from tip to tip, and that the leading-edge9, of each blade crosses over the axial line to become the leading-edge 9, of the other, and as the trailing-edge 10, likewise crosses over to become the trailing edge 10, of theother, the forward blade faces after twisting, as shown in view in Fig. 2, are

it is secured by short bolts 14. At dia-- metrically opposite points, the walls of shell 12, are formed with inclined slots 15, closely fitting the central part 5, of thepropeller which is inserted edgewise into the same from the lower open ends'of the slots. The upper ends of the slots are closed and the length of the .slots being the width of the central f no blade-connecting part 5, the inner edge of said part is drawnifirmly against the shaft flange 2, by the bolts HQ These slots 15, extend longitudinally of the sleeve and in oblique direction and are made to accurately fit' and accommodate the part 5, which passes transversely through the shell or hub 12.

A- metal strap or ring 19, is passed around the exterior of the tubular hub 12, and

"through snugly fitting holes 16, formed in the central part 5, atopposite sides of said hub. The ends of the strap are drawn together and secured by bolting or welding, thus strengthening the. shell 12, and at the same time,

fixing the propeller against end play. The

strap 19, may also be secured to the shell by screws 20, to anchor it securely in place. The propeller is thus held firmly against thrust and torque and relies for resistance to centrifugal force solely uponits own integrity without participation of the member or hub 12, which may therefore be made relatively light in weight.

- The outer end of theshell is provided with i a finishing cap 17, in the form of a hollow cone of thin material telescopedover the end,

and secured thereto by screws, 18, and serving to diminish air resistance.

This' novel form of propeller permits of the same being mounted edge-wise'in respect to the drive-shaft, so that the axis of rotation is coincident with the transverse axis of the eration.

'entis:

propeller. This disposition of the propeller i not only results in a lighter weight structure,

but also simplifies the same, at thesametime giving certain advantages in elli'ciency of op- 'My invention is not confined-to the par ,ticular constructions of part's,:as herewith disclosed, as various modifications may be made in several different parts, without, however, departing from the spirit of my invention.

The propeller is made preferably of a solid metal plateand of any well known suitable light-weight metal alloys, such asaluminum al oys, for example duralumin. I Having thus'described my inventiomwhat I claim and desire to secure by Letters Pat- .1. An aeronautical propeller having a.

- nonaxially perforated central part and oppositely extending bladesconnected therewith and crossing the driving-axisso that said axis is parallel with the wide dimension of said central part and said propeller twisted so that the trend of the twist is substantially continuous from end to end to equal result-ant pitch-angles for each blade with the convex faces of both blades disposed on the same side of the propeller;

2. A single piece metal aeronautical propeller formed from an elongated relatively thin nonaxially perforated plate with blades convex on one side of one blade and convex on the other side of the other blade, and twisted in one direction from end to end to equal resultant pitch-angles for each blade.

3. A single piece metal aeronautical propeller formed from an elongated relatively thin nonaxially perforated plate with oppositely extending blades convex on one side of one blade and convex on the other side of the other blade, and twisted in one direction from tip to tipto equal resultant pitch-angles for each bladeso that both convex faces are on the forward side of. the propeller.

4. An aeronautical propeller having a helical twist about its longitudinal axis and formed from a blank having acentral part with blade portions connected therewith and convex on one side of one blade portion and convex on the other side of the other blade and a hub driving-memberconstructed and arranged so that said central part of thepropeller passes transversely through it in locking engagement therewith to'transmit torque and thrust,- said fiat central part lying sub: stantially along the axis ofrotation, and

means for securing said central part against movement relativelyto said driving-member. '6. A propeller having a comparatively this cent a Pa to h ch th bl des are centhereof so that the transverse axis of said central part is coincident with said drivingaxis, and means for securing said parts together.

8. A propeller having a central part to which the blades are connected, a hub comprising a body provided with a transverse passage extending along the axis of the hub for receiving said central part, said central part extending through said passage, and

means for securing said parts together.

9. A propeller having a central part to which the blades'are connected, a hub comprising a body having a flange at its inner end and provided with a transverse'opening for receiving said central part, said central part extending through said opening and means for locking the parts together, a driveshaft provided with a flange and means for attaching it to the flange of said hub body.

10. A propeller having a central part to which the blades are connected, a hub comprising a body having a transverse opening extending through it for receiving said central part, said central part extending through said opening, orifices in said central part-upon each side of said body to the exterior thereof, and locking members passing through said orifices and secured to said hub bod 11 A propeller having a central part to which the blades are connected, a hub comprising a body having a transverse passage therethrough for receiving said central part, said central part passing through said passage in the body, said central part being formed with orifices lying to the exterior of said body, and a locking-member passing around said body and through the respective orifices and secured in such position.

12. A propellerhaving a ccntra'l part to which the blades are connected, a hub comprising a tubular body, similarly disposed slots formed in the opposite walls of said body and open at one end thereof, but closed at the other, and said central part being inserted in said slots, and a closure for, the open ends of said slots.

13. A propeller having a central part to which the blades are connected, a hub com-- prising a tube flanged at its inner end and provided in its opposite walls with simi-- larly arranged slots which open at said inner end of the tube, said central part being mounted in said slots and fitting the same, perforations formed in said central part to the'exterior of said tube, a strap passing around said, tube and through said perforations in the central part and secured to said tube.

14:. A propeller having a central bladeconnecting part with oppositely extending blades and twisted in one direct-ion from end to end to equal resultant pitch-angles for each blade so that the leading edge of one blade passes through the driving-axis and becomes the leading edge of the other blade, a hub comprising abody provided with a transverse passage for receiving said central part, said central part being mounted through said passage and containing said drivingaxis, and means for securing said parts to gether.

15. In an aeronautical propeller, a broad and comparatively thin central nonaxially perforated mounting, part having blades connected therewith and crossing the driving-axis so that the broad dimension is substantially parallel with said driving-axis, and driving connections engaging the broad faces or sides of said central-part for drivingthe same. I

16. In an aeronautical propeller, a nonaxially perforated central mounting part formed broad and comparatively thin and having blades attached thereto and crossing the driving-axis so that the broad dimension is substantially parallel with said drivingaxis, and driving connections for said part comprising a member provided with a passage axially coincident with said driving-axis and having oppositely arranged openings through which said central-part extends with practically unobstructed spaces at the sides of said central-part in the region of the drivlng-axis.

17.. An aeronautical propeller having a central mounting part connecting the oppo sitely extending blades, the propeller being of helical form about its longitudinal axis from tip to tip of the blades, and a tubular driving-member having the said central part secured diametrically across the tubular member so as to leave the opposite sides of said central part unobstructed within the tubular member.

In testimony whereof, I have hereunto set I

Images