US2426635A

US2426635A - Engine, propeller, and fan drive

Info

Publication number: US2426635A
Application number: US422823A
Authority: US
Inventors: Mercier Pierre Ernest
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-12-13
Filing date: 1941-12-13
Publication date: 1947-09-02
Anticipated expiration: 1964-09-02

Description

Sept. 2, 1947.

P. E. MERCIER 2,426,635

- ENGINE, PROPELLER, AND FAN DRIVE Filed Dec. 13, 1941 s Sheets-Sheet 1 1 INVENTOR. F a/"re [meal Ale/"czar JATTORNEYS Sept. 1947. 3 P. E. MERCIER 2,426,635

ENGINE, PROPELLER, AND FAN DRIVE Filed Dec. 15, 1941 3 Sheets$heet 2 55 /Y J3 7 J: I a

72 56 as 67 r. l 7.9 59 1o 7, 1s 77 mvmqn. PIE/Tc [rnesf Merezer ATTORNEYS Sept. 2, 1947. P. E. MERCIER' ENGINE, PROPELLER, AND FAN DRIVE.

Filed Dec. 13, 1941 3 Sheets-Sheet 3 INVENT OR.

m M 9 I ATTORNEYS Patented Sept. 2, 1947 UNITED STATES PATENT OFFICE ENGINE, PROPELLER, AND FAN DRIVE Pierre Ernest Mercier, New York, N. Y.

Application December 13, 1941, Serial No. 422,823

14 Claims. 1

This invention has reference to aircraft.

The drag of a wing or a nacelle subjected to the slipstream of a tractor propeller is known to increase directly with the velocity of the slipstream and is known to change the efficiency of the propeller. It is also commonly known that when the propeller is placed behind the wing and operates as a pusher propeller (and not as a tractor) loss of efficiency is due to the fact that the screening effect of the nacelle and the wing disturb the operation of said propeller. In either case the loss of efficiency of the propeller will be localized mainly in the neighborhood of the nacelle and near the axis of rotation of the propeller;

The present invention has for its principal object arrangements resulting in the elimination of the greater part of the above drawbacks. The invention is in principle applicable to aircraft propelled by tractor as Well as pusher propellers, but is of particular interest in the case of pusher propellers. It consists essentially of the association of a propeller and a member of the turbine or fan type, preferably arranged to rotate on one and the same axis, said members being driven at different speeds, the turbine turning from 2 to 5 times more rapidly than the propeller and preferably in an opposite direction, and the turbine being so related to the propeller as to bring about a smooth How of air axially of the central portion of the area defined by the rotating propeller and rearwardly of the direction of travel of the aircraft, so that, in the case of a tractor propelled aircraft, the slipstream effect is reduced, and, more particularly in the case of an aircraft driven by a pusher type propeller, so that the screening effect of the nacelle and turbulence of the boundary layer of air will be minimized and the efficiency of the propeller increased.

According to one advantageous embodiment of the invention, the turbine is arranged in an annular fairing concentric with the spinner of the propeller or with a fairing which extends about the propeller shaft and the turbine drive gearing, either intermediate the propeller shaft and the spinner or from the propeller toward the engine, and which continues the streamlined contour of the spinner. The annular fairing, depending on whether the turbine is in the front or rear of the propeller, is carried by the nacelle or supported from the mounting for the shaft driving the propeller or transmitting to it the motor torque. The annular fairing may be limited in a longitudinal direction to the zone of action of the fixed or movable vanes of the turbine, or may be a fixed fairing of greater length.

The concentrically arranged fairings in effect define a generally annular passage open at both ends through which air is drawn by the action of the turbine for the purposes hereinafter more full detailed. This annular passage is advantageously arranged in communication at its forward end with an intake orifice or slot extending annularly about the nacelle at a point in its length rearward of its greatest diameter and through which air from a boundary layer is sucked into the annular passage by the action of the turbine and discharged therefrom through an annular discharge outlet or nozzle defined between the concentrically arranged fairings at the rear end of the annular passage. This discharge nozzle is preferably somewhat constricted as compared with the cross-section of the annular passage toward its forward end. This constriction may be brought about by appropriately tapering the annular fairing so that it is frustoconical in shape and presents an outer contour generally conforming to the streamlined shape of the nacelle.

The annular passage may also receive air that has been led within the nacelle through an inlet orifice or orifices other than that mentioned above and which has been utilized for cooling the engine or operating elements thereof.

According to still another modification, the annular passage may merely open forward to receive air from the boundary layer traveling along the nacelle surfaces, in which case the sucking action of the turbin will accelerate flow of the boundary air along the nacelle Without first drawing it through slots or orifices in the nacelle fairing.

A further feature of the invention resides in the arrangements for driving the propeller and the turbine from the same power source through differential gearing whichinsures that the power delivered by the motor or engine is divided in a ratio related to the speeds of rotation of the driven members with respect to that of the motor shaft. In one embodiment of the invention, for example, the number of revolutions of each of th two driven members is related to the runnin speed of the engine by a simpl ratio so that as the speed of the propeller is increased or decreased relative to the engine speed the speed of the fan is decreased or increased, as the case may be, relative to the engine speed. By varying the pitch of the propeller, and therefore its speed, the speed of rotation of the turbine may be varied for one and the same engine speed.

A considerable advantage obtained from this arrangement is that the turbine may be operated tions intheepeed of the turbine.

these particular .fiight conditions.

3 at a higher speed as the speed of the aircraft is increased during normal flight with a corresponding decrease in the R. P. M. of the propeller.

, This is precisely what is desirable from the point of View of improving the propulsive efliciency; for

3 the greater the speed of translation the more the circumferential speed of the propeller blade may be reduced to increase eiiicie-ncy. At the same time the dilferential gearing arrangements permit the propeller to be revved up to a high speed and operated at a high R. P. M., and, .if

desired, with an increased pitch, during take-ofi and in climbing operations. Under theseconditions, speed of translation is relatively low and the problems that the turbine is desired to overcome are not presented to am'arked degree. Consequently, the speeding up of the propeller above-mentioned varying-conditions of'aircraft operation.

According to one particularly simple embodiment of the invention, the predetermined divi sion of the-power input is ob-tainedby means of gear of relatively large diameter with internal teeth arranged in concentric relation to a relatively small; sun gear and operatively' connected thereto-by-intermediate planetary gears. In this embodiment of the inventionthe motive poweris 1 T appl-ied'to the ringgear and. the propeller is driven by the ring gear through the intermediate or-planetarygears which are mounted on a carrier that: is either fixed to oroperatively connectedjor driving-the propeller. Th turbin is sion ,of'the powerinput in a predetermined fixed rat-iobetween the propeller and the turbine, and also insuresthatvariations in the speed of the propeller will be accompanied, byinverse variathe several gears the ringgear, the planetary gears, the central sun gearare so chosen as to insure that throughout the contemplated operatingrange of propeller speeds, theturbine will have a speed of from two to five times that of the propeller.

V In accordance with an optional modification of V i the invention it is possible to apply all the motive powerto the propeller operating alone during the This is accomplished by a looking .or braking means: for immobilizing the centralpinion connected to the turbineinwhich case all of the power applied tethering gear is utilized 'indriving the planetary gearsthroughtheir path' of revolution about the central piniomand these in turn transmit the available-power to the propeller to the exclusion of the. turbine;

In a further modified arrangement such locking; or brakin :meansqmay be, provided for im- The ratios of V engine aircraft or aircraft provided both with propellers and auxiliary propulsive means.

According to still another embodiment of the invention, the turbine may be replaced by a wheel carrying numerous radially extending vanes or blades appropriately curved and arranged to function similarly as a ventilating fan. In this embodiment the fan may advantageously be mounted for'rotation about the propeller axis with the blades projecting radially through an annular slot in the spinner portion of the propeller assembly at the rear of the propeller.

If the. fan. or turbine is arranged between the differential gearin and the propeller, the differential gearing is advantageously enclosed by fairing forming an extension of the streamlined contour of the spinner, and the concentrically spaced annular auxiliary fairing may be centered with respect to the fairing surrounding the easing for the differential gearing by means of streamlined bracing wires or streamlined piano wires, in thisWa-y reducing drag on the air drawn by the turbine through the annular passage there-between, "When the turbine is arranged to the rear of the propeller, in the .cas of a pusher propeller, the differential gearing may besupported .by the overhanging end of the. propeller shaft, and itscasing may rotate with and carry a combination of gear wheels including a ring the'mtermediait Theinvention will nowbe described re fullywith: reference to. the accompanying drawings by wayofexample. In saiddrawings:

Figure 1 isra part vertical longitudinal section and part elevation of an application of the invention toa propulsive nacelle provided witha liquid blnexatkthe rear of'the nacelle or-of the fuselage,

as thecase maybe.

Figurev 3 is an axial section of a reducing gearing according to the invention, the casing of which rotates with the propeller, and in which the turbine and propeller are arranged at oppo site, sides of the reducing gear, th turbine being in? the rear of the propeller with relation to the support ofthedrive shaft.

Figure l is a partially developed cylindrical section .on the line A- -A. of Fig. 3 showing the section .of the vanes of the turbine and its straightening vanes carried by a flange integral with the drive shaft.

Figure 5 i-sa vertical section of still another modification. of the invention in which the re- .duction gearing and the fan are disposed on opposite-sides ofthe propeller.

Figure dis a view partly in vertical section and partly in side elevation showing an engine nacelle with the propeller arrangement appliedthereto.

Referring to- Figure 1 the fairing of the engine nacelle is shown at I. It presents in front an axially arranged opening 2 communicating by means of the pipe 3' with the air intake of the engine 4-. Machine guns or cannon 5 are arranged in *front of the engine in the case of a military airplane.

The wing profile .on which the engine-nacelle is mounted is seen at '6. The pipes carrying the cooling liquid of the engine are shown at and '8; These-pipes lead to radiator members-such as of the maximum cross section of the nacell of the engine admit of the drawing-in of the boundary layer, the air entering through slots ll passing through the radiators 9 and I9 and then passing with the air entering through the slots l2 to and through the turbine.

The casing of the reduction gearing associated with the propeller and the turbine is seen at I6. It is supported by the frame M. The motive power is conveyed by the transmission shaft I6. The annular fairing l6 surrounds the turbine Ha, which carries vanes i'l. Piano wires I6 center the fairing l6 with respect to the central body I9, and streamlined fairings 26 enclose the piano wires l8.

One of the blades of the propulsive propeller is shown at 2 I, its spinner at 22,

Referring to Figure 2, we find again in Figure 2 the vanes ll of the turbine the wheel of which is seen at 23. Straightening vanes 24 are carried by the annular fairing I6. A propeller blade is seen at 25, its cuff at 26. The spinner 22 of the propeller is provided with an internal flange 21. The propeller hub 28 is locked on the cone 29 which forms the end of the shaft 30, The latter is centered on the opposite side of the propeller by means of the bearing 3| carried by the member 32, which receives the motor couple by means of the coupling 33 which is integral in rotation with the end of the transmission shaft !5. The member 32 is carried by the bearing 3 3 mounted in the front plate 35 of the casing IS. The plate 35 is provided with lugs 66 for attachment. The member 32 supports the ring gear 3?. Intermediate gears 38 mesh with the gear 37, the stub shafts 39 of these gears being supported by the intermediate gear carrier 4-6 keyed to the propeller shaft 36. The intermediate gears 39 actuate the central pinion ll, which is integral with the wheel 23 of the turbine. These mem-' bers are centered on the shaft 39 by means of the bearings 42 and 43, and supported in the casing by the bearin 44.

At 45 and 46 there is shown diagrammatically a pawl and ratchet wheel between the wheel 23 and the casing, which is provided for the purpose of immobilizing the wheel 23 during th take-off. A control (not shown) may release the wheel 23 at the desired moment when the aircraft is in normal flight. It is clear that a brake or equivalent member of a conventional type would serve the same purpose. A similar braking or looking arrangement may be provided to hold the propeller against rotation under certain flight conditions so as to rely solely upon the fan or turbine for propulsion.

Referring now to Figure 3 the axis of the device is marked 4!41. 48 is the drive shaft. It is supported by a bearing or system of bearings occupying the place of the reduction gears 39 in the case of Figure 1.

The shaft 48 has an internal recess 59 and an axial pipe 5!. The pipe conveys lubricating oil under pressure through passages such as '52 to the space 54 and the bearings for the gears disposed therein. The oil is returned through passages such as 53 to the recess 56 after one or several oil pumps (not shown) have forced it into the space 54. The propeller hub is seen at 55, the root of a blade at 56, its cuff at 51.

The propeller hub is carried by a member 58, centered on the shaft 48 by means of

bearings

59 and 66. The member '58 plays the part of a plate closing the casing 6|. The stub shafts 62 of the intermediate gears 63 are fixed in the member 6|.

The intermediate gears mesh outwardly with the internal ring gear '64 carried by the member 65 which is keyed to the shaft 48. The intermediate gears mesh inwardly with the central pinion 66, which is guided on the shaft 48 by the bearings 57 and 68. The pinion 66 is integral with the turbine wheel 69, which carries the vanes 10. The vanes is move in the interior of the annular fairing ll which through th vanes 12 is integral with the flange '53 keyed to the shaft 46. This shaft also carries the flange M, secured by the nut it which centers the nosepiece 16.

The external fairing of the rear portion of the nacelle is seen at H, its interior surface at 16; it defines an annular passage for removing the cooling air circulating in the nacelle.

Figure 5 shows an embodiment of the invention in Which the casing for the reduction gearing is fixed and arranged in advance of the propeller and on the opposite side thereof with respect to the turbine wheel or fan associated with these two elements. In the case of this figure,. the turbine is replaced by a wheel carrying numerous vanes like a ventilating fan. This embodiment is moreover characterized by the feature that this wheel turns at the end of the propeller shaft and is driven by the central pinion by means of a torque rod or tube. concentric with the propeller shaft and arranged inside the latter in an appropriate bore.

In Figure 5. like members as shown in previous figures ar identified by corresponding reference numerals. '56 is a propeller blade, 51 its culT, 28 the propeller hub. The pitch changing mechanism is shown diagrammatically at 8|. It is provided with an insulating disc 82 carrying. the usual current supply rings. (The pitch changing mechanism shown is of the electric control type.) The carbon brush-carrying block customarily associated with the rings of the disc 82 is seen at 83, The fan or turbine wheel is provided with vanes such as 8 which are secured in place by

flange members

85 and 86. The

members

85 and 86 are secured together for rotation on the end 8'? of the propeller shaft, being supported in bearings 88 and 89. The fan assembly thus formed is caused to rotate b means of the grooves 9| arranged in the member 66 and carried by the outside of the torque rod 96. A plug 92 tightly closes the central opening in th member 86.

The spinner i6 is centered on the member 86 by means of a partition in the shape of a truncated cone is. A labyrinth joint 96 prevents the leakage of oil between the member 85 and the propeller shaft. The propeller hub 26 is secured to the propeller shaft 94 by means of the conggntionai spline and groove connection shown at u a.

The shaft 94 is provided with oil return pas sages such as 95. It is supported in the nose of the reduction gearing casing ill! by bearings 96 and 91. This shaft 9 is part of the support 46 for the stub shafts 39 carrying the intermediate gears 68.

The internal ring gear 3'! is supported by two plates i536 and N33 with a peripheral flange portion thereof held between opposed flanges carried by the plates. The plate I56 is centered on and supported by the member 96 by means ofv the bearing 93. The other, m3, is in one piece with the shaft 32 to which the motive force is applied. The central pinion M is centered by means of the bearings 99 and I 94. It is integral in rotation with the torque rod 93.

If desired, a slip coupling may be inserted betweenthe. torque rod-93 and the central pinion 41 or between the said. torque rod 93- and the member-86;

The. housing for the reduction gearing is supported by tubular struts such as I4, some being attached to the plate 35 by means of bolts 36, the others being fixed to the case IDI by means of bolts I02; 7

In Figure 6, l is theengine nacelle, containing the engine t and its radiators 9 and I0, connected tothe engineby the pipes 1 and 8. The transmission shaft I links the engine 4 to the mechanism shown on a larger scale in Figure 5 and enclosed in the outer fairing I05, An air intake is arranged in front of th nacelle at I09. It feeds through the passage I08 to the radiators by means of branched. conduits shownschematically at an and arranged in the rear of the engine 4. An annular slot is arranged between the fairing Hi5 and the rear edgeof the fairing of the nacelle i, which latter is providedwith flaps me that allow for varying'the slot according to flight conditions.

Thefixed fairing M5 is extended by means of the movable fairing '19 of the propeller hub and by the-spinner l6 associated with the fan wheel or turbine,

While the invention has been more particularly described in association with a pusher-type propeller, it will be understood that it may equally be'employedwith a tractor-type propeller in which case the fan or turbine may be employedjsecondarily to supply compressed air to the engine, the fan or turbine serving as the active member of a supercharger for example, or the fan ,or turbine may deliver the air to a rear propulsive nozzle, or part of the air may be delivered to the supercharger and part to a rear propulsivenozzle as desired.

Having now fully described my invention, 1'

1. In an aircraft propulsion system including an engine, a nacelle and a pusher type propeller mount-ed adjacent the rear of the nacelle to rotate upon theaxis of said nacelle, in combination, 7

a fan rotatable upon the'same axis as .the propeller and arranged todirect flow of air from the boundary layer about'the nacelle rearwardly adjacent the hub of the'pro-peller, and a differential driving connection between'said engine and said propeller and between said engine and said fan adapted tovary the speeds of the propeller and of the fan inversely with respect to each other uponthe occurrence of differential rotation of either the propeller or the fan with respect to therotation of the engine drive shaft.

2; In an aircraft propulsion system including rotation of either the propeller or the fan with respect to the rotation of the engine,

3; In an aircraft propulsion system including an'eng-inaa nacelle enclosing the engine, and a pusher type propeller located adjacent the rear of the nacelle, in combination,a fan mounted to be rotatable about the same axis as the propeller andarranged to-direct flow-of the boundary layer of air about the nacelle rearwardly adjacent the hub of the propeller, a driving connection between said engine and said'propeller, means for driving the fan at a speed sufficient substantially to reduce the drag of the boundary layer of air on the nacelle in the Vicinity of the propeller, and including means operatively connected between said propeller driving connection and said fan driving means for varying the speeds of the propeller and of the fan inversely with respect to each other in response to occurrence of diiferential rotation of either the propeller or the fan with respect to the rotating speed of the engine drive shaft.

4. In an aircraft propulsion system including an engine, a nacelle enclosing the engine, and a pusher type propeller located adjacent the rear of the nacelle, in combination, a fan mounted to be rotatable about the same axis as the propeller and arranged to direct flow of the boundary layer of air about the nacelle rearwardly adjacent the hub of the propeller, a driving connection between said engine and said propeller, means for driving the fan in a direction opposite tothat in which the propeller is driven and at a speed'sufi'icient substantially to reduce the drag of the boundary layer of air on the nacelle in the vicinity of the propeller, and including means cperatively connected between said propellerdriving connection and said fan driving'means for varying the speeds of the propeller and of the fan inversely with respect to each other upon occurrence of differential rotation of either the propeller or the fan with respect to the rotating speed of the engine drive shaft.

5. In an aircraft propulsion system including an engine and a nacelle enclosing the engine, in combination, a pusher type propeller located adjacent the rear of the nacelle, a fan arranged to direct flow of air from the boundary layer of air about the nacelle rearwardly adjacent the hub of the propeller, a shaft driven by said engine, a chain of gearing driven by said'shaft for driving said propeller and said fan and including'differential gearing between said shaft and-said propeller and between said shaft and said fan adapted to vary the speeds of the propeller and of the fan inversely with respect to each other whenever the speed of one or the other varies relative to the speed of said shaft.

6. In an aircraft propulsion system including an engine and a nacelle enclosing the engine, in combia-tion, a' pusher type propeller located adjacent the rear of the nacelle, a fan arranged to direct flow of air from the boundarylayer of air about the nacelle rearwardly adjacent the hub of the propeller, a shaft driven by said engine, a Chain of gearing driven by said shaft and in cluding a large internal ring gear driven from said shaft, an intermediate planetary gear'meshing therewith, and a central pinion meshing with said planetary gear, said fan being connected with and driven by said central pinion, and said propeller being connected with and driven by said planetary gear, so that the torque applied totthe propeller and to the said fan isin a fixed ra 1o.

7. In "an aircraft propulsion system including an engine, ainacelle enclosing the engine, and a pusher type propeller located adjacent 'therear of the nacelle and driven by said engine,in combination, a fan rotatable around the same axis as the propeller and arranged to direct air rearwardly from the nacelle adjacent the hub of the propeller, and means driving said fan at a spe d at least twice that of the propeller, said means including a large internal ring gear driven from said shaft, an intermediate gear meshing therewith, and 'a central pinion meshing with said intermedite gear, said fan being connected with and driven by said central pinion, and said propeller being connected with and driven by said intermediate gear, so that the torque applied to the propeller and to the said fan is in a fixed ratio.

8. In an aircraft propulsion system including an engine and a nacelle enclosing the engine and 'a pusher type propeller located adjacent the rear of the nacelle and driven by the engine, in combination, a fan mounted. rearwardly of and adjacent the propeller and rotatable about the same axis as the propeller, said fan being further so arranged as to induce how of air rearwardly adjacent the hub of the propeller, and means for driving the fan at a speed at least twice that of the propeller during normal flight operation, thereby to reduce turbulence in and drag of the boundary layer of air on the nacelle in the vicinity of the propeller, said means for driving the fan including a differential driving connection between said fan and said propeller and between said propeller and said engine adapted to vary the speeds of the propeller and of the fan inversely with respect to each other whenever the speed of one or the other varies relative to the speed of the engine.

9. In an aircraft propulsion system including an engine, a nacelle enclosing the engine, and a pusher type propeller driven by said engine and located adjacent the rear of said nacelle, in combination, a fan rotatable around the same axis as the propeller and arranged to direct air rearwardly from the nacelle adjacent the hub of the propeller, and means driving said fan by means of a torsion rod concentric with and located within the engine drive shaft at a speed at least twice that of the propeller, said means including a large internal ring gear driven from said shaft, an intermediate gear meshing therewith, and a central pinion meshing with said intermediate gear, said fan being connected with and driven by said central pinion, and said propeller being connected with and driven by said intermediate gear, so that the torque applied to the propelle and to the said fan is in a fixed ratio.

10. An aircraft as claimed in claim 3 wherein the said fan is arranged between the engine and rearwardly adjacent the axis of said propeller at,

a sufiicient speed to substantially eliminate drag of the boundary layer of air on the nacelle in the vicinity of said propeller, said means including a differential driving connection between said engine and said propeller and between said engine and said fan adapted to vary the speeds of the propeller and of the fan inversely with respect to each other upon the occurrence of differential rotation of either the propeller or the fan with respect to the rotation of said engine.

10 12. In an aircraft propulsion system including an engine, a nacelle enclosing the engine, and a "pusher type variable pitch propeller located adjacenttheirear of the nacelle, in combination, a fan: rotatable upon the same axis as the propeller and arranged to direct air from the boundary layer "adjacentthe' nacelle rearwardly adjacent the; axis of the propeller, a driving connectionbetween said-engine and said propeller and between said engine and said fan, said connection including a differential driving mechanism adapted upon variation of the propeller speed effected by varying the pitch of th propeller to inversely vary the speed of the fan with respect to the propeller speed while said engine speed is maintained substantially constant.

13. In an aircraft propulsion system including an engine, a nacelle enclosing the engine, and a pusher type propeller located adjacent the rear of the nacelle, in combination, a fan rotatable around the same axis as the propeller and ar ranged to direct air rearwardly from the nacelle adjacent the hub of the propeller, a driving connection between said engine and said propeller and between said engine and said fan which includes a differential driving mechanism adapted to drive the propeller at increased speed upon reduction of the speed of the fan when operating at a given engine speed, and means for locking said fan against movement so that all the power of the engine drive shaft may be applied to said propeller, as during take-off.

14. In an aircraft propulsion system including an engine, a nacelle enclosing th engine, and a pusher type propeller located adjacent the rear of the nacelle, in combination, a fan rotatable around the same axis as the propeller and arranged to direct air rearwardly from the nacelle adjacent the hub of the propeller, a driving connection between said engine and said propeller and between said engine and said fan for driving said fan at a speed sufiicient to substantially reduce turbulence in and drag of the boundary layer of the air in the vicinity of the propeller, said driving connection including a differential driving mechanism acting upon reduction of the propeller speed to increase the speed of the fan for a given engine speed, and means for locking the said propeller against movement so that all of the power of said engin shaft may be applied to said fan under desired flight conditions.

PIERRE? ERNEST IVIERCIER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,274,743 R-osskopf Mar. 3, 1942 1,712,622 Kruckenberg et al. May 14, 1929 1,386,493 Guyot- Aug. 2, 1941 2,208,156 Gilbert July 16, 1940 1,691,593 Tank Nov. 13, 1928 1,847,093 Martin Mar. 1, 1932 2,076,232 Goodman Apr. 6, 1937 1,414,418 Jaray May 2, 1922 2,041,792 Stalker May 26, 1936 2,041,794 Stalker May 26, 1936 2,347,153 Hagen n Apr, 18, 1944 2,022,900 Parlecka Dec. 3, 1935 2,270,912 Theodorsen Jan. 27, 1942 1,813,645 Townsend July 7, 1931 (Gther references on following page) iwu'mbr Name Daite 1, MPhrs0n Nov. 14, 1933 Wilson et 41 July 8,1941 Lear May 1a, 1943 T 'De'seversk July 9, 1940 Breene et a1. July 21, 1936 -Squirs Oct. 13, 1931 Adams Mar. 14, 1939 Nllh lb e l