US2088255A - Compression propeller - Google Patents

Description

July 27, 1937. H. L. ADAMS COMPRESSION PROPELLER 2 Sheets-Sheet 1 Filed NOV. 22, 1932 July 27, 1937. ADAMS 2,088,255

GOMPRESS ION PROPELLER Filed Nov. 22, 1932 2 Sheets-Sheet?- '{IIIIIIIII/I/ m'mm wm Patented July 27, 1937 UNITED STATES PATENT OFFICE 2,088,255 COMPRESSION PROPELLER Herbert Luther Adams, Washington, D. 0. Application November 22, 1932, Serial No. 644,560

16 Claims.

This invention relates to propellers for flying machines, and the application is a continuation in part of my prior application Serial Number 461,412, filed April 14, 192-1, and since maturing into Patent No. 1,888,418.

One of the main objects is to provide a variable propeller that may be utilized at a low pitch to' givegreater tractive force when starting upon the ground and may be changed to a much higher pitch and greaterlength of blades as the altitude of the aeroplane above the ground is increased .to a point where the air has become more rare and in that way greatly increasing the efliciency of the propeller.

Another object is to provide auxiliary propellers which have a steep inclination of the entering edge to draw the air out of the dead center and to derive tractive force therefrom and to destroy parasite resistance on the main engine and fuselage thereby.

A still further object is to'provide a means for varying the angle of attack upon the dead center of air in the path of the. main propeller so that with rarefied air the same efliciency may be obtained by the auxiliary propeller as in the more dense atmosphere.

A still further object is to provide a. main propeller with substantial increasable length of blades in the more rarefied air or when conditions require to increase the area of attack and to give a greater tractive force.

A still further object is to provide a propeller control device that may be operated manually through a power force to control the pitch of the propeller or it may be operated automatically by atmospheric pressure responsive device associated was obtained with the pitch control mechanism to relieve the, operator from paying attention to this detail of changing the pitch of propeller.

To these ends my invention consists in certain novel features, which I will now proceed to describe and will then particularly point out in the claims. a

Figure 1 is a front view of variable pitch adjustable propeller with an adjustable auxiliary propeller in accordance with this invention.

Figure 2 is a plan view of the propeller shown in Figure 1 with a diagrammatic view of the starter of the propeller.

Figure 3 is a longitudinal sectional view through the main crank shaft of the engine showing the method of varying the pitch and length oi. the propeller shown in Figure 1.

Figure 4 is a section taken on the line 4-4 of Figure 3.

Figure 5 is a section taken on the line 5-5 of Figure 3. I 1

Figure 6 is a section of the rear end of the crank shaft taken on the line 6-6 of Figure 3'.

Figure 7 is a'fragmentary longitudinal section 5 of a modified-form of propeller.

Figure 8 is a fragmentary section through another modified form of propeller.

Figure 9 is a cross section through the hub of propeller, a modification of Figure 3.

Figure 10 is a diagrammatic view of the propeller showing the effect of the auxiliary propeller in forcing the air from the central part and compressing near the outer rim to give greater tractive force and reduce parasitic resistance or friction to the onrushing fuselage.

Referring to the drawings, in detail, the numeral I indicates a pair of propeller blades which project from lateral extensions of a hub structure formed of a pair of separable sections 2 and 3 disposed transversely of the crank shaft or propeller shaft 12, and secured together by some suitable means such as the split collars 33 and bolts 34. Although two blades and two hub extensions are shown, any number desired may be employed.

Each of the hub extensions is of hollow construction, and is-provided with a transverse'partition l which divides the interior of the extension into an inner portion comprising a pressure chamber or piston chamber 6, and an outer portion adapted to receive therein the inner end portion 8 of a propeller blade I. This portion 8 of the propeller blade has its peripheral faceformed with diagonal grooves 9 which slidably receive therein pins l0 projecting radially from the'inner face of the hollow extension receiving the blades. A piston 5 is slidably mounted within the chamber 6, and is connected with the portion 8 of the blade I by means of a pistonrod l which 40 slidably extends through the partition 1. The crank shaft or propeller shaft |2 is of hollow construction, and the interior thereof is connected with the chambers 6 of the hub structure by means of fluid conducting pipes l I which open into the chambers 6 adjacent the partitions 1. The interior of the crank shaft is adapted to have a compressed fluid conducted therethrough to the parts or pipes H, such fluid entering the crank shaft through a thrust connection l3 extending into the rear end of the crank shaft through a suitable fluid tight bearing in a head I8 mounted on said rear end. The thrust connection l3 receives the fluid through a hollow pressure arm I! having a pipe connection IS with a suitable source of fluid pressure supply, not shown. The pressure arm I4 is pivotally mounted adjacent its center as indicated at l6, and is provided with a pressure adjusting rod II in threaded engagement with some suitable rigid element such as the rear bearing support for the crank shaft l2.

The head I8 is preferably formed with an annular chamber 26 which is connected by means of a pipe IS with the source of fluid pressure supply. Opening into the chamber is a fluid conducting pipe 2| which extends into and through the hollow interior of the crank shaft, and also partially through the hub structure to a pressure chamber or piston chamber 22 formed in the forward face of the hub structure, and extending axially thereof in alignment with the foremost portion of the crank shaft. Slidably mounted within the chamber 22 is a piston 23 having a piston rod 24 projecting forwardly from the hub structure. The piston rod 24 is pivotally connected by means of a bolt or pin 25 with a pair of links 26 which are also pivotally connected respectively by means of bolts or pins 21 with a pair of auxiliary propeller blades 26. Although two of the auxiliary propeller blades 28 are shown and described, this number may be varied as desired.

Preferably the number of auxiliary blades will correspond to the number of the main blades with the auxiliary blades preferably arranged in a manner to bisect the spaces between the main blades.

In order that external power may be applied to the'crank shaft to start the motor of the flying machine, I provide a gear 29 fixedly mounted on the crank shaft, and operatively connected by means of intermediate gears 30, 30a and 30b with a gear 30c flxedly mounted on the crank shaft 3| of a starting or auxiliary motor, a connectin'g rod or piston rod of which is shown at 32.

In operation, fluid under pressure is admitted through the thrust connection i3 to the interior of the crank shaft |2, from where it is passed through the pipes H to the pressure chambers 6. The propeller blades I have a tendency to slide outwardly with respect to the hub structure by the action of centrifugal force, and an appropriate pressure is maintained within the pressure chambers for coaction with the pistons 5 to hold the blades in the desired position in accordance with prevailing conditions, such as the altitude at which the machine is flying. When it is desired to increase the effective length of the blades,

the pressure within the chambers 6 is reduced to permit the pistons to be drawn by centrifugal force toward the partitions I. Owing to the inclination of the grooves 9 having the pins I0 slidably received therein, the pitch of the blades is automatically reduced or increased with the reduction or increase in the eifective length of the blades.

In order to relieve pressure on the inner faces of the pistons 5, and to permit the escape of any fluid that may seep past the pistons, each chamber 6 is provided at its inner end with a vent 31 as shown in Figure 3. This vent may also be in the nature of a tube 35, as shown in Figure 9, and the ports or tubes 35 from the several chambers all extend to the pipe 36 for connection there similarly to pipe 2|. The other end of pipe 36 is connected with separate opening similar to chamber 20 with vacuum or other connection similar to pipe IS.

The adjustment of the auxiliary blades 28 is accomplished independently of any adjustment of the main blades by means of fluid pressure which is admitted to the pipe 2| through the pipe I! and chamber 20. External pressure on the auxiliary blades tends to force them apart toward their maximum arc of rotation, and when it is desired to reduce their are of rotation, the internal pressure on the piston 23 is increased to draw the blades 28 toward each other through the action of the rod 24 and links 26. Owing to therelatively low speed of the tips of the auxiliary propellers in distance per second, as compared to the corresponding speed of the tips of the main blades l, the pitch of the auxiliary blades should be high at all times. The action of the auxiliary blades tend to force the air outwardly from the axial line of the hub structure, thereby compressing the air to a certain extent within the path of the main blades I, and thinning the air in the immediate path of the flying machine body to decrease air resistance on the latter.

In the embodiment of the invention shown in Figure 7, each of the hub extensions 33 is formed with a recess 39 to slidably receive an inner end portion of a propeller blade 40 therein. The inner portion of the blade and the wall of the recess 39 will be provided with any suitable means such as grooves and pins to maintain the proper angular position of the blade with respect to the hub extension.

The inner end portion of the blade is of hollow construction to provide a chamber 4| having a removable closure 42 at the inner end thereof. Slidably mounted within each chamber 4| is a piston 43 having a stem 44 slidably extending through the closure 42 into the hub wherein it is rigidly anchored. The stem 44 is provided with' a lengthwise extending bore 45, one end of which opens into the chamber 4| adjacent the inner face of the piston 43, and the other end of which opens into the hollow crank shaft 46.

In operation, the blades 40 are normally urged outwardly by centrifugal force whereby the inner end of the chamber 4| is moved toward the stationary piston 43. when it is desired to move the blades inwardly to shorten the eiIective length thereof, or to prevent further outward movement of the blades, fluid under pressure is admitted through the hollow crank shaft to the bore 45 for' expansion within the chamber 4| inwardly of the piston 43. A pressure relief vent 41 is provided for the recess 39, and a similar vent 46 is provided for the chamber 4| at the outer end of the latter. Both of these vents are open to the atmosphere.

In the embodiment of the invention shown in of the recess 53 and the inner end portion of the blade to maintain the latter in proper rotative position with respect to the extension. Slidably disposed within each chamber 52 is a piston 55 which is connected with "the inner end of the adjacent blade 54 by means of a piston rod 56 slidably extendingthrough the partition 5|.

chambers 52 adjacent the partitions slidably disposed within the hollow extension .49, which also forms a pressure chamber, is a piston 51 having a piston rod 58 connecting the same with a diaphragm 59 disposed transversely and forwardly of the extension 49. Opening into the rear portion of the hollow extension 49 are fluid conducting pipes 60 which also open into the Also opening into the rear portion of thehollow extension 43 is a bore Bl extending lengthwise of the propeller shaft 62 and adapted to be connected in: any suitable manner with a source of fluid pressure supply, not shown. The chambers 52 are provided at their inner ends with pressure relief vents 63 which are open tothe atmosphere.

- 'In use, the structure shown in Figure 8 may be operated manually or automatically, as desired. In the manual operation of the same,suflicient pressure is admitted through the bore GI and pipes 60 to the chambers 52 to maintain the blades 54 in proper position in accordance with prevailing conditions. In the rarer atmosphere, or at any time that it is desired to increase the effective length or the pitch of the blades, the pressure is reduced sufiiciently to enable the blades to move outwardly by the action of centrifugal force.

When it is desired to operate the device automatically, a predetermined constant pressure is maintained therein which is substantially sufficient to hold the blades against the action of centrifugal force in a comparatively dense atmosphere; With such an adjustment, when higher altitudes are reached. the external pressure on the diaphragm, and also the external'resistance to centrifugal movement of the blades, decrease ina corresponding degree, whereby the compressed fluid is gradually transferred from the chambers 52, through the pipes 60 to the chamber within thehollow extension 49. When descending, as lower altitudes are reached, the external pressure on the diaphragm, and the external resistance to centrifugal movement of the blades increase, and the compressed fluid is retransferred from the hollow extension 49 to the chambers 52.

It is apparent that the basic principles of' this invention can be used with any type of engine including a radial engine without departing from .the spirit of the device.

The chamber 20 could be placed between the propeller and the engine by any one skilled in the art if desired without departing from the spirit of the invention. I

It is to be noted that the auxiliary propeller can be made. unadjustable without departing from the spirit of the invention and can be used with anytype of propeller.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is:

1. In a flying machine, a propeller shaft, a hub carried by said shaft and having lateral extensions, propeller blades extending into said extensions and having slidable and rotatable connections therewith, means to provide pressure chambers within said extensions, pistons within said chambers, rods connecting said-pistons with said blades, and hydraulic means for moving said pistons.

2. In a flying machine, a propeller'shaft having a fluid pressure conduit, a hub carried by said shaft and having lateral extensions, propeller blades slidably and rotatably extending into said extensionsfmeans to provide pressure chambers within said extensions, pistons in said chambers adapted to slide the blades upon the introduction of fluid under pressure to the chambers, means to establish communication between said chambers and fluid pressure conduit for admitting fluid under pressure to the chambers, having pressure relief vents'for said chambers, and coacting means on said extensions and blades for rotating the blades upon sliding movement thereof.

3. In a flying-machine, a propeller shaft, a hub carried by said shaft and having lateral extensions, propeller blades slidably extending into said extensions, means to provide pressure chambers within said extensions, pistons in said chambers adapted to slide the blades upon the in-- troduction of fluid under pressure to the chambers, means for introducing.fluid under pressure to said chambers, and having pressure relief vents for saidchambers.

4. In a flying machine, a propeller shaft having a hub, a forward extension and a plurality of lateral extensions on the hub, means within each of said extensions to provide a pressure chamber, pistons slidable in said chambers, propeller blades slidably extending into said lateral extensions, piston rods connecting the blades with the pistons in the lateral extension pressure chambers, a diaphragm disposed crosswise of said forward extension, a piston rod connecting the diaphragm \viththe piston in the forward exten sion pressure chamber, and having constant communication between all of said chambers.

5. In a flying machine, a ropeller shaft, propeller blades slidably mounted with respect to the shaft and extending laterally therefrom, a diaphragm'movable axially of said shaft, and

means operatively connecting the diaphragm with said blades whereby movement of the diaphragm axially of the shaft causes sliding movement of said blades.

6. In a flying machine, a propeller shaft, radially movable propeller blades extending laterally from said shaft, a diaphragm movable axially of said shaft, and means operatively connecting the diaphragm with said blades whereby movement of the diaphragm axially of the shaft causes radial movement of said blades.

7. In a flying machine, a propeller shaft, a hub carried by said shaft and having lateral extensions, propeller blades slidably extending into said extensions, having pressure chambers in inner end portions of said blades, pistons slidably received within said. chambers, means for anchoring said pistons to said hub, and means to provide a fluid pressure conduit opening into said chamber.

8. In a flying machine, a propeller shaft having a fluid pressure conduit, a hub carried by said shaft and having lateral extensions, propeller blades slidably extending into said extensions,

. propeller blades exmnding laterally from and rotatable with said shaft, auxiliary propeller blades forwardly of the main blades and rotat.

able therewith and extending diagonally from said shaft at a forward and outward inclination and extension, and means for adjusting said forward and outward inclination and extension ofsaid auxiliary blades.

' 10. In a flying machine, a propeller shaft, main propeller blades extending laterally from and rotatable with said shaft, and auxiliary propeller blades forwardly of the main blades and rotatable therewith and extending diagonally from said shaft at a forward and outward inclination and extension.

11. In a propeller, a shaft, elongating main propeller blades movable in a radial direction and attached to and rotatable with said shaft, auxiliary propeller blades forward of the main blades, said auxiliary blades being attached at their bases by pivoted connections, the center lines of said connections each being excentric, non-parallel and non-intersecting to the center line of said shaft, direct acting means to move said main propeller blades radially and controllable means to adjust said auxiliary blades about said pivoted connections while said auxiliary blades are in use.

12. In a propeller, a shaft, elongating main propeller blades movable in a radial direction and attached to and rotatable with said shaft, auxiliary propeller blades forward of the main blades, said auxiliary blades being attached to the base by pivoted connections and secured to rotate with said shaft, the center lines of said connections each being capable of a tangential relation to a cylinder of suitable size concentric with said shaft, and controllable means to adjust said auxiliary blades about said pivoted connections while in use.

13. In a propeller, a shaft, elongating main propeller blades movable with respect to said shaft in a radial direction and rotatable with said shaft, auxiliary propeller blades forward of the main blades, said auxiliary blades being attached to the shaft by pivoted connections, the center lines of said connections each being capable of a tangential relation to a cylinder of suitable size concentric with said shaft, direct acting means to adjust said main propeller blades radially and controllable means to adjust said auxiliary blades about said pivoted connections.

14. In a propeller shaft, main propeller blades attached to said shaft and rotatable with said shaft, auxiliary propeller blades forward of the main blades, said auxiliary blades being attached to the shaft by pivoted connections and secured Y to rotate with said shaft, the center lines of said connections each being capable of a tangential relation to .a cylinder of suitable size concentric with said shaft, and controllable means to adjust said auxiliary blades about said pivoted connections while in use.

15. In a propeller, a shaft, variable pitch main propeller blades attached to said shaft, auxiliary.

propeller blades forward of the main blades, said auxiliary blades being attached to said shaft by pivoted connections, the center lines of said pivoted connections being capable of a tangential relation to a cylinder parallel to said shaft, and controllable means to adjust said auxiliary blades about said pivoted connections while said auxiliary blades are in use.

16. In a propeller, a shaft, variable pitch main propeller blades attached to said shaft, auxiliary propeller blades forward of the main blades, said blades being attached to said shaft by pivoted connections, the center lines of said pivoted connections each being capable of a tangential relation to a cylinder concentric to said shaft, controllable direct acting means to vary the pitch of said main propeller blades, and controllable means to adjust saidauxiliary blades about said pivoted connections while said auxiliary blades are in use.

HERBERT L. ADAMS.

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