US2041169A - Propeller - Google Patents

Description

P. DLCESARE 3 Sheets-Sheet -1 4 PROPELLER Filed April. 27, 1933 P. m CESARE Wi" "1T 1,169

P'ROPELLER Filed April 27, 1933 '5 Sheets-Sheet 5 refilled with air.

siren STATE-s. PATENT ori-ICE PROPELLER Pierino Di Cesare, Chicago, Ill;

Application/April 27, 1933, Serial No. 668,181

16 Claims.

The invention relates to propellers and` more in particular to a novel propellerconstruction adapted for use in air craft or for marine purposes. The present application is a continuation `in part of my copending application Serial No.

623,249, led July 18, 1932, an-d abandoned August 9, 1938.

Among the objects of the present inventionis to provide a novel construction of propeller for air craft and marine purposes which is of greater eflciency than those now being constructed and employed. In the present embodiment such increased efficiency is obtained without increasing the size or dimensions of the propeller and Without adding any weight thereto, both of which are highly important factors inthe design an-d construction of air and marine propellers.

A further object is to provide a novel construction of air or marine propeller provided with a -central portion having a reduced passage or opening for receiving, guiding andejecting the` fluid acted on by the propeller for propelling an airplane, vessel or other object, through the medium or fluid in which it is operating, whereby to increase the eniciency of the propellerover the` prior forms ofA propellers of the same size, weight or material.

Another object of the invention is the provision cf a propeller for airplanes provided with anovel' f construction of hub and central portion adding to the efliciency of the propeller. In the various forms of prior constructions the central portion around the hub serves no useful purpose and inY fact creates a vacuum which naturally has to be This vacuum tends to create a tremendous drag which has to be overcome by the power of the engine. It has been quite commonly accepted that the vacuum createdby the inemcient central porti-on of the propeller was of `little importance and it has often been cited thatY this created vacuum was of actual iiying aid as the engine and fuselage following lled in this vacuum, but actual flying tests with such` prior forms of propellers and the present novel propeller construction have proven thatfsuoh is not the fact. By means of the present' invention, this disadvantage has been eliminated and the space behind the central portion of the propeller is filled with air that is scooped up or collected by the contour of the p-ropeller and exhausted or ejected into the trailing vacuuml which is created as the aircraft is driven forwardly.

A further object yof the invention is yto-provide a nevel propeller construction formed with a longitudinally extending passage, throat or open ing` adapted to collect the approaching air and exhaust or eject the saine rearwardly off the pro# peller into the trailing vacuum created behind the propeller. This exhausted air forms a cool-V ing medium adapted to `cool the engine.

Still another object of the invention is the provision of a novelpropeller in which the leading edge'cuts the air sharply substantially tothe center ofthe propeller, thereby `'greatly increasing the efficiency and effective operative lengthV thereof yover prior propellers'and those Whichare at the present time, standard equipment;

In such prior forms, a substantial partofthepropellers length constitutes the central portion which effects a drag and at best has no operative or advantageous effect in propelling the airplane. In the present novel` design;` substantiallythe entire propeller length is effective in propelling the craft through theair;

Still another and further object of the invention 'is the provisionof apropeller that is substantially vibrationless in operation. In the present embodiment, this is accomplished byscoop'lng up and passing the air through the hollow central portion -cf the propeller which functionsto balance and stabilize` the same. ThisA portion guides the scooped air and steadies the operation.

Numerous actual flying.v tests of' thepresent propeller have been made and these tests have shown that aircraft equippedv with this typefof propeller show a better response to 'the' controls. They;v also show `a greatly increased' performance and steady pull in climbing and the tests disclose that an Iairplane equipped with the present propeller will take off or rise ata much less distance or in a smaller space than similar planes equipped withthe prior or standardtypes of ,propellers Flying tests at full throttle; and static thrust shcw a marked increase in eciency and speed, while stalling tests disclose thattheengine speed f must be greatly decreasedor cut-dowrr before the plane will come to astall: These tests also show that the present type of propellerminimizes the danger of a tail spin since thereis'a more*` direct flow of air or air stream lwhich flows rearwardly along the fuselage and' stabilizes -the'pl-ane. All lof these tests vhave been performed'on sifni lar planes using both a standard `or-\pric`ir commercial type of propeller'and a propelleras 'dis-i closedin the present application-.h

The invention further consistsin',v and an ob-f ject thereof is to provide a novel typefof-"adjustable hub construction or central portion-ferai' propeller of the present "design or embodiment, in which the propeller hub and the centralseclv tion of the propeller is made adjustable and the dimensions of the passage, throat or opening adjacent the hub are varied, depending on the load or thrust imposed on the propeller. This construction permits the utilization of the same propeller for motors of varying sizes or horse power.

Another object is to provide a novel sectional hub construction in which the sections are automatically adjusted whereby to scoop or collect varying amounts of air in the passages or pockets provided therefor and to eject such collected air laterally or rearwardly of the propeller.

A still further object of the invention is the provision of a propeller of this novel type provided with one or more longitudinally extending passages, throats or openings and which is admirably adapted for marine use. Although the shape or contour of the blades of a propeller for marine use may vary somewhat over those for airplanes or other use, the principle involved and the function thereof is the same as in propelling an airplane,v even though it is operating in water. Increased efficiency is secured by the use of this propeller over those now in standard use whereby greater propulsion, speed and power is secured.

Further objects are to provide a construction of A maximum simplicity, efficiency, economy, and operation, and such further objects, advantages and capabilities as will later more fully appear, and as are inherently possessed thereby.

The invention further resides in the combination, construction and arrangements of parts illustrated in the accompanying drawings, and while there is shown therein a preferred embodiment, it is to be understood that the same is susceptible of modification and change, and comprehends other details, arrangements of parts, features and constructions, without departing from the spirit of the invention.

In the drawings: Y

Fig. 1 is a View in rear elevation of the propeller construction;

Fig. 2 is a view in side elevation thereof;

Fig. 3 is a view in front elevation of the propeller;

Fig. 4 is a fragmentary view in perspective with the propeller section taken in a plane represented by the lines 4 4 of Fig. 1;

Fig. 5 is a fragmentary view in vertical cross section taken in a plane represented by the line 5-5 of Fig. 1;

Fig. 6 is a fragmentary view in perspective of the central portion of the propeller;

Fig. 7 is a view in vertical cross section through a. modified form of propeller in which the central section thereof is made adjustable;

Fig. 8 is a fragmentary view in vertical cross section taken through the hub and central section of the construction similar to that shown in Fig. 7, but showing the position of the telescoping members of the propeller when there is little or no load imposed thereon.

Fig. 9 is a view in vertical cross section through the adjustable central section and hub taken in a plane represented by the line 9-9 of Fig. 7;

Fig. 10 is a fragmentary view in rear elevation of the adjustable hub and central section;

Fig. 11 is a fragmentary view in perspective of the adjustable construction;

Figs. 12 and 13 are slightly modified forms of telescoping sections;

Fig. 14 is a view in rear elevation of a marine propeller;

propeller;

Fig. 16 is a view in perspective thereof;

Fig. 17 is a view in vertical cross section taken in a plane represented by the line ll-l'l of Fig. 14; and

Fig. 18 is a fragmentary view in vertical cross section of an alternate form of marine propeller in which the hub is positioned exterior of the body of the propeller.

Referring more particularly to the drawings and specifically to the disclosure in Figs. l to 6 of the drawings, the embodiment selected to illustrate the invention in these figures comprises propeller I having outwardly or oppositely extending blades 2 formed with a leading or cutting edge 3. This propeller may be employed to propel an airplane or other aircraft by either pulling or pushing it through the air. In the prior designs of` propellers and those which are now standard or commercial equipment for airships or other aircraft, a great part, and in most instances substantially thirty-five percent of the propeller length comprises the central section which is at best ineffective and has no useful function in propelling the aircraft through the air.

In the pres-ent embodiment, this leading edge 3 and the effective operative portion of each blade extends for substantially the full length of the blade so that the effective surface area thereof is greatly increased.

As clearly disclosed in Figs. l to 6 inclusive, the blades are dished adjacent the central portion and this dished portion or depression 4 communicates with a passage, throat or opening 5 ntermediate the outer plate 2'fl carrying the blades and the inner plate 6 adjacent the hub la of the propeller. This ldished portion or depression forms a pocket for collecting the air acted on by the propeller blade and directs the air into the reduced passage or throat 5 from where it is exhausted or ejected laterally or rearwardly of the propeller. This form of construction not only gives greater surface area or effective operative surface of the propeller blade for acting upon the air or fluid in which it is operated, but collecting and scooping up of the air and the passage thereof through the passages 5 gives greater efficiency and propulsion to the propeller. This ejection of the air laterally of and rearwardly of th-e propeller eliminates any possibility of forming a vacuum behind the central part of the propeller. It further stabilizes the operation of the propeller whereby to reduce or eliminate vibration thereof, and the stream of air passing rearwardly toward and along the fuselage of the airplane tends to stabilize the same in its travel.

The construction of the propeller may comprise an integral member or it may consist of sections as shown in Figs. 7 to 13 inclusive. In this construction, the blades 1 are made similar in contour to those shown in Figs. 1 to 6 inclusive, and each blade is provided with a dished portion or depression 8 adjacent the hub for collecting the air and directing it through the passage 9 from where it is ejected or exhausted laterally or rearwardly.

Each passage or throat 9 is made adjustable, the size thereof depending upon the load or thrust of the propeller. In Fig. 8 there is disclosed the position of the adjustable section when little or no load is imposed upon the propeller, while in Fig. '7 the parts are `disclosed when there is a full load, in which case the passage or throat is reduced in cross section.

In order to permit an adjustment of the passages 9, the propeller is made sectional, the for- WarilV ,or` outer section `I ll carrying the, blades l and is slidable or movable longitudinally of the driveor propeller shaft II. The rear section I2 is mounted stationary on the drive shaft and is provided with an upper and lower forwardly ex- A tending flange I3 adapted to receive therein or therebetween the rearwardly extending flanges I4 of the front section I0. Thus these members telescope together and are adapted to form therebetween the adjustable passages or throats 9 for thepassage of and ejection of the air acted on and `collected by the blades and which air is guided. therethrough by reason of the depression or dished portion 8 adjacent the hub. The hub construction is likewise made sectional and comprises a quill or inner stationary hub part I5 mounted on the propeller or drive shaft II by means of a key I6, This stationary hub I5 at its forward endabuts against a collar or stop member I'I which is threaded onto the shaft. A washer I8 and a nut I9 are adapted to secure this collar or stop in position and prevent it from backing ofi of the threaded end of the propeller shaft. The stationary hub part I5 is splined, being formed with ribs 2B having grooves k2i therebetween. These grooves 2| are adapted to receive ribs or utes 22 and the ribs or utes 2e are adapted to be received in channels 23 in a slidable or movable hub member 24 which is adaptedto encompass and slide on the inner stationary hub I5.

Thus the inner and outer hub members l5 and 24 respectively, provide a splined construction in which the members are provided with complementary surfaces so co-related and coacting to permit relatively free sliding movement therebetween. If desired, coacting faces between the complementary members may be provided with races adapted to receive bearings 25. The outer hub member 24 is provided with an annular ange 26 adapted to be connected to the front plate le by means of bolts or other suitable retaining means 2'I. A rear hub plate 28 is mounted on the reduced end 2,9 of the inner hub member I5 and is suitably connected to the inner plate I 2` by bolts or other retaining means 3l). A retaining or lock nut 3l is adapted to be threaded onto this reduced end 29 and to lock the hub plate 23 and plate I2 stationary upon the drive or propeller shaft II.

Mounted within the passages or throats 9 is a coil spring 32A adapted to bear against the inner faces of the plates I and I2 and exerting a compression against the plate Il! tending to force this plate and the blades formed thereon or carri-ed thereby, outwardly, as disclo-sed in Figure 8, the pressure of the air against the propeller overcoming whatever screw action there might be present to force the section I e outwardly. When the propeller is operated under load, the plate I0 is forced inwardly and the spring 32 takes this rearward thrust. Since this spring 32 is mounted within the passages 9 and the air which passes therethrough, this spring is provided with a leather or other flexible covering 33. A spring 34 mounted on this covering is adapted to keep the covering expanded against the opposite side walls so as to at all times cover the springs against the entrance of dirt or other foreign matter.

As the spring 32 is? of considerable compression and tends to force the plate I0 andthe movable hub 24 outwardly, the invention comprehendsl the provision of a spring 35 seating against the annular ange 26 and an annular flange 36 ,formed on the collar Aor, stopirnemloerll l.. This spring acts as a shock absorbers@ as torreventthe spring 32 from forcing the, plate In outwardly with too great aforoe, thuslpreventing danger of the movable `hub. member 2,4 from striking against the collar Il. whentheload is removed ,from the propeller. A cover or housing 3l` isadapted to enclose the nose or front portionA of the hub so as to prevent the entrance of water, ice, dust and other foreign matter. This nose., housing or cover is detachably secured to the annular flange 26 by bolts or other sutableretaining means 38. From the above disclosure, it willbe readily seen that by varying the strength or compression of the spring` 32, the saine propeller may` be utilized for engines of various sizes orl horse power. It will also be clearly evident; that the diameter and pitch of the propellerV remain constant even though the sectionsor platesIU and I2 forming the propeller are shiftable o1' movable relative to each other.

In Figs. 12 and 13 are disclosed modications of the telescopic plates. In Fig. 12 the outer plate III@L is provided with upper and lower flanges 39 adapted to receivethe flanges 40`of the inner plate I2a. Thisl construction is similar to that shown in Figs. 7 and 8, with the exception that the flanges of theouter plates are exterior of and adapted to receive the flanges on the inner plate, rather than the reverse construction as disclosed in the prior figures.

In Fig. 13 the outer plate is similar in construction to that disclosed'in Fig. 1.2 while the inner plate 4I is devoid of upper and lower flanges. In this construction the plate itself is received within the flanges 39 of the `outer plate I lla and which anges are adapted to slidev or move thereover.

In Figs. 14 to 18 inclusive, there is disclosed a propeller. quite similar inoperation and function as the propeller disclosed in Figs. 1 to 6 inclusive, but in which the contour has been altered in order to adapt it for marine purposes. Since this propeller functions to push a boat or other vessel through the water or medium in which it is operating, the mounting thereof is reversed from that of the airplane propeller in which the rear plate 6 faces the front-ofthe fuselage. Were this type of propeller used in pushing a plane through the air, the plate 6 would necessarily face in a reverse direction so as to push rather than pull the airplane through the atmosphere. In the marine type of propeller, the rear plate 42 extends or faces away from the boat. This marine propeller is shown as provided with a pair of blades 44 provided with a leading edge 45. Throughout a substantialportion of the length of these blades, they are dished or concaved as at 46 whereby to scoop up the water or iiuid being acted upon and direct and project this fluid through a throat or passage 4l extending adjacent the hub 48 of the propeller. The water or iiuid passing through the throat or passage 41 impinges against the side walls 49 thereof, and helps to rotate the propeller. The water which is discharged or ejected from the throat 4l will pass laterally therefrom in a manner similar to that of the ejected air in the preceding disclosures, due to the constructions, contour and rotation of the blades and throat and the direction of travel of the vessel or structure being propelled.

This ejection adds greater efficiency and pushing power to the propeller, whereby the speed at which the motor is turning over may be reduced, ora smaller motor may be provided to accomplish the same power and speed as a larger motoremploying the` prorand `standard types of v t0 a large extent.

propellers. The discharge or ejection of the water or uid gives added hydraulic propulsion.

'In Fig. 18 there is disclosed an alternate form of marine propeller in which no interior hub is provided but the hub is exterior of the propeller and comprises an outer boss or hub member 50 and an inner boss or hub Vmember 5I suitably keyed to the shaft 52. A lock nut 53 retains the propeller in adjusted position. It is of course t0 be understood that the propeller shaft 52 need not pass through the body of the propeller but a bearing member or hub may be provided exterior thereof on one of the plates, whereby leaving unobstructed the passage through the propeller.

With the clockwise rotation of the propeller as shown in Figure 1, the fluid will enter both throats or openings 5 in opposite directions, both towards the center. Due to the direction of rotation, the fluid of the right hand throat will be compressed against the upper right portion thereof, while a partial vacuum or void will exist in the upper left portion at the point of application of the dotted line from 5; the opposite conditions prevailing as to the lower portion of the throat. Thus it will be seen that the uid will pass through the throat in opposite directions but on opposite sides of the shaft and interference between the two oppositely flowing currents will be avoided The same conditions and operation are found in the adjustable and marine propellers.

Although a greater efficiency is secured by the use of my propeller, the voyage is smoother since s the agitation of the water is greatly minimized and the wake and swell following a vessel equipped with the novel propeller is noticeably decreased.

When the novel propeller is used on an airplane or for propelling air, the construction and design is such that in scooping or collecting the air and discharging or ejecting it from the longitudinal central portion of the propeller, the noise or metallic sound emitted is greatly minimized. This sound is generally caused by the broad surfaces of lthe blades striking the air and thereby causing vibration which is transmitted to the tip of the blades and thence to the atmosphere. In the present construction such broad surfaces are not present. v

From the above description and the disclosure in the drawings, it will be readily seen that the invention comprehends a unique or novel form of propeller in which the design, contour and construction thereoi greatly increases the efficiency over prior types of propellers. Thus, without increasing the size or weight of the propeller and in fact reducing the weight thereof, because it requires less material, this invention permits a decrease in the size of Vpower plant or an increase in the power and speed with the same power plant.

Although I have disclosed the propeller as particularly adapted for propelling aircraft or boats, it is to be understood that it is equally as well adapted to propel any other structure in which a propeller may be employed, or for propelling currents of air or other fluid.

Having thus disclosed the invention, I claim:

l.. A propeller provided with propelling blades and a central portion having a hub for connecting the propeller to the drive shaft, and telescoping sections at said central part adapted to be adjusted relative to each otherV and so constructed and arranged as to provide an adjustable outlet from the eifectivesides of said blades for directing and ejecting fluid collected therefrom.

2. A sectional propeller construction adapted to be mounted on a drive shaft and rotatable therewith, comprising a plate fixed on said drive shaft and a plate slidable longitudinally thereon, said slidable plate carrying the propelling blades.

3. A propeller construction adapted to be mounted on a drive shaft, comprising a pair of members rotatable with said dn've shaft but movable relative to one another and longitudinally of said shaft, one of said members carrying the propelling blades and said members being spaced apart to form a fluid passage therebetween.

4. A propeller construction adapted to be 'mounted on a drive shaft and rotatable therewith comprising propelling blades, an adjustable central section provided with telescopic parts providing a passage 'therebetween through which fluid acted on by said blades is directed and ejected, said passage being automatically adjusted by the load imposed on the propeller.

6. A propeller construction adapted to be mounted on a drive shaft and rotatable therewith comprising propelling blades, an adjustable central section provided with telescopic parts providing a passage therebetween through which fluid acted on by said blades is directed and ejected, said passager being automatically adjusted by the load imposed on the propeller, and compression means tending to extend and separate said parts.

7. A propeller construction adapted to be mounted on a drive shaft and rotatable therewith comprising propelling blades, an adjustable section centrally of said propeller and provided with parts adapted to be automatically adjusted to provide a passage therebetween of varying cross section depending on the load, means acting against the load tending to separate said parts and increase said cross section, and means acting to absorb any shocks to said parts resulting from a sudden decrease or removal of the load on the propeller.

8. A power-driven propeller for aircraft and marine use provided with outwardly extending blades, a member spaced from said blades and a passage intermediate said blades formed by said blades and member for receiving the fluid being acted on by the body of said blades and said passage communicating with the rear face of each blade, the rear face of said blades being so constructed and arranged as to collect fluid acted thereon and directing it toward the passage, said passage receiving and ejecting said uid away from the blades.

9. A power-driven propeller provided with blades adapted to act upon the ud in which it is operating, a plate spaced from said blades, and a tapered passage formed by said blades `and plate and located centrally of said blades and communicating with the rear face of each blade for axially directing and discharging from the propeller the fluid being acted upon and collected by the blades.

V10. A power driven propeller provided with spaced plates, one of which forms the propelling blades, a hub therefor, and a passage intermediate said plates and communicating with the rear face of said blades, said blades being so constructed and arranged that fluid acted upon and collected by said rear face is directed inwardly from the ends of the blades and toward the hub and ejected through said passage for the purposes set forth.

11. A power-driven propeller for aircraft and marine use provided with oppositely extending blades and a plate spaced from said blades, a hub therefor, and a tapered passage formed by said blades and plate on opposite sides of the hub and communicating with the rear face of each blade, said passage forming an outlet adjacent the hub for the fluid collected by the rear faces of said blades and directing and ejecting said collected fluid therethrough.

12. Apower driven propeller for aircraft and marine use provided with oppositely extending blades and a member spaced fromV said blades, a hub therefor, and a tapered passage formed by said blades and member at the rear face of said propeller and extending on the opposite sides of said hub and longitudinally of the blades, the rear face of said blades being so formed as to collect and direct the fluid acted upon, inwardly from the ends thereof to the hub and through said passage into the space behind the propeller.

13. A propeller for use onairplanes provided with a hub adapted to receive the drive shaft and blades extending outwardly therefrom for propelling the airplane through the air, the central portion of said propeller connecting said blades being provided with a member spaced from the blades and forming an opening communicating with the rear faces of said blades and adapted to collect the air acted on by the rear faces of said blades and direct it inwardly toward the hub and through said opening and then rearwardly into the space directly behind said propeller.

14. An airplane propeller provided with a central part adapted to be connected to the drive shaft, blades extending outwardly from said central part for propelling the airplane through the air, said blades having their rear face dished to scoop and collect the air adjacent thereto and said central part being provided with a member spaced from the blades and dening a passage therebetween, the air collected by said dished blades being directed inwardly to said passage and ejected therethrough and rearwardly therefrom into the space behind the central part to eliminate any tendency of the propeller to form a vacuum in said space.

15. An airplane propeller provided with a central part having a hub for connecting it to the drive shaft, blades extending outwardly from said central part and adapted to propel the airplane through the air, a plate spaced rearwardly of said blades, said part being provided with a tapered opening formed intermediate said blades and plate and communicating with the blades,

said blades being dished adjacent said opening to collect the air and direct said collected air inwardly towards the central part and through the opening and eject it into the space behind the central part of the propeller so as to lill said space with the collected air and prevent the formation of a vacuum thereat.

16. A propeller comprising outwardly extending blades adapted to act upon the fluid in which the propeller is operating, and an adjustable 'nnb construction therefor including telescopic members adapted to form a passage therebetween to receive uid acted on by the blades and to direct said fluid rearwardly of the propeller.

PIERINO DI CESARE.

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