US2315213A

US2315213A - Variable pitch propeller

Info

Publication number: US2315213A
Application number: US267999A
Authority: US
Inventors: Linehan Edward
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-04-15
Filing date: 1939-04-15
Publication date: 1943-03-30
Anticipated expiration: 1960-03-30

Description

March 30, 1943. E. LINEHAN 2,315,213 I VARIABLE P ITCH PROPELLER March 30, 1943. E. I INEHAN 2,315,213

VARIABLE PITCH PROPELLER y Filed April 15, 1939 2 Sheets-Sheet 2 42 r 324 :f Z7 f 26 45 35 40 33 7 32 A5*/ 34 3/ 2/29 Si 22 27 Il', 'Il /l/ l 1'/ /ll /0 E5 26 \40 20 a7 4/ l /7 9 Ardiff/ara bhe/7a d Hof. WMA

Patented Mar. 30, 1943 UNITED STATES PATENT OFFICE VARIABLE rrron PnorELLER Edward mnehan, Hillman, Mimi. Application April 15, 1939, serial N0. 267,999

2 claims. (cl. 17o-lss) My invention relates to an improvement in variable pitch propeller wherein it is desired to provide a propeller in which the pitch is automatically variable and which is capable of permitting movement of the blade into a fullfeathering position in case the motor should cease to function.

Automatic pitch propellers have been constructed in the past. Many of these propellers are capable of accomplishing much the same result to that desired in the present invention,

but my construction is designed to require an` exceedingly small number of parts to function in the proper manner.

It has been found that unless thev propeller mechanism is properly constructed, the blades of the propeller will not move into full-feathering position in case one of the motors should cease to function. In any other position of the blades. the angularity of the blades cause the blades to rotate the crank shaft of the motor, causing the motor to draw fuel from the fuel tanks which ordinarily is not exploded. An accumulation of unburned fuel will then be forced into the hot exhaust pipe, creating danger of an explosion and endangering the lives'of the personsin the plane. Furthermore, when the motor ceases to function for any reason, it is desirable that the rotation of the motor be stopped as soon as pos.

sible, in order to prevent further damage of the motor by any parts ofthe same .which might be broken.

It is an object of my invention to provide a device which will automatically permit the blades to move into full-feathering position in an extremely short space of time, and which if desired may be operated manually to cause such full-feathering of the blades to take place.

It is a purpose of my invention to operate the propeller mechanism to control the angularity of the blades by means of a rotating disc drum or element and to create friction or in any suitable way to change the speed of rotation of this disc with respect to that of the propeller shaft.

variable pitch propeller mechanism in which the propeller blades are normally urged into` one exposition. In the rotation of the propeller shaft,

if the speed o'f rotation of the shaft increases, additional friction is created to rotate the blades to greater angularity, while if the speed of rotation of the propeller shaft decreases, the friction tendency will be lessened, permitting the propeller blades to rotate in a manner to decrease the pitch of the same. Thus, the propeller blades are adjusted in angularty in accordance with variations in the thrust of the propeller blades in operation and may also be manually controlled. v

It' is a purpose of the preferred form of my invention to provide a spring or resilient means for resiliently urging the blades of the propeller toward low pitch and to provide means for moving the propellers toward a higher pitch. Whell this means for moving they propeller toward a higher pitch is removed, the propeller will automatically move back into low pitch without any means except the spring means described and the normal tendency of the blades to move in this direction when other pressure is released,

causing such movement.

These and other objects and novel features of my invention will be more clearly and fully sct forth in the following specification and claims. In the drawings forming a part of my specication: Figure 1 is a cross-sectional View through my variable pitch propeller mechanism, the section being taken on a plane through the axis of the propeller shaft.

Figure 2 is a cross-sectional vieW through my variable pitch propeller mechanism, the position of the section being indicated by the lines 2-2 of Figure 1.

Figure 3 is asection taken on a plane .parallel to Figure 2, the position of the section being indicated by the line 3-3 of Figure 1. l

Figure 4 is another section taken on planes parallel to the sections in Figures 2 and 3, the

position of the section being indicated by the line 4-4 of Figure 1.

The variable pitch lpropeller mechanism A isv shown of a particular shape and conformation. but may of course be widely changed in shape and proportion to lfit varying requirements. The variable pitch propeller mechanism A is designed to be mounted upon the propeller shaft I9 which is shown having a substantially cylindrical portion I I, a spline portion I2, a threaded portion i3, and an attaching portion I4, preferably cylindrical in section. The splined portion I2 of the shaft I9 extends through a spider I5 to which the propeller blades are secured in a manner which will be laterdescribed, and lto which the outer casing I9 of the mechanism A is secured through spacing blocks I1.

The spider I5 is best illustrated in Figure 3.

of the drawings and is shown provided with ears or lugs I9 to .which the spacer blocks I1 are attached by means of bolts or other suitable means. The spacer blocks I1 are provided with slots or apertures into which the lugs or ears I9 extend, and the bolts 20 extend through portions of the spacer block I1 on either side of these apertures for accommodation of these lugs I9 as well as through the lugs.

Between the attachment with the spacer block I1, the spider is provided with flattened surfaces 2I from which the sleeves 22 extend. The sleeves 22 are preferably each formed with a pair of

bearing surfaces

23 and 24 which engage cooperating bearing surfaces on a tapered bushing 25 recessed in the end or shank A26 of the propeller blades 21.

A ring 29 is secured to the end of the shank 29 oil each propeller, and this ring 29 is provided along a segmental portion of its periphery with gear teeth 30 as indicated in Figure 1 oi' the drawings. A pair of supporting rings 3| having a relativelyilexible washer 32 therebetween are interposed about the shank 26 of the propeller between the ring 29 and the anti-friction bearing 33. The anti-friction bearing 33 is preferably of the split type so that it may be replaced, and is held inv place by a threaded ring 34 which may also be formed of two halves if desired so that it may be removed from the propeller shank without removing the ring 29. When the rings 34 have been threadably secured to the casing I9, the natural tendency for the blades 21 to be pulled outwardly by centrifugal force is overcome by engagement with the anti-friction bearing 33 and even while considerable centrifugal force is urging the blades outwardly, they may be turned easily because of the bearings 33.

Within each of the sleeves 22 and extending in to the body of the propeller blades 21, I provide a pair of relatively

rotatable shafts

35 and 39. The shaft 35 is provided with an oiT-set pin or key 31 which prevents rotation of the shaft 35 with respect to the spider I5, and one end of the spring 39 is vanchored at 49 thereto. A projecting end 4I on the shaft 35 extends into an axial aperture in the shaft 39 so that the

shafts

35 and 39 may be supported in alignment, but relatively rotatable. The outer end of each spring 39 is secured at 42 to the shaft 39. The shaft 39-is secured by an off-set pin 43 or any other suitable means to the propeller blade 21.

It will be noted that the

shafts

35 and 39 are so constructed as to not interfere with axial movement of any of the blades 21, but they are so positioned as to create a tendency for the blade other forces act upon the blade, the blade will remain in low pitch position. 'I'he gear teeth 39 on the ring 29 are designed to engage a bevel gear 44 encircling the projecting end I4 of thepropelier shaft I3. Attached to this bevel gear by bolts 45 or any suitable means, I provide a spur gear 49. These

gears

44 and 49 are rotatable with respect to the shaft I9 and while they normally rotate with this shaft, they'are not keyed or otherwise attached thereto. Apinion 41 upony a shaft 49 engages the gear'49 and is extremely small with respect thereto so that the shaft 49 will rotate a number of times for each revolution of the gear 49; l

A partition member and support 50 is illustrated secured by bolts 5I or other suitable means to the casing I9. The shaft 49 extends through the partition 50, and a gear 5I is mounted on the opposite side of the partition from the pinion 41. The partition 59 thus forms a support for the shaft 49. The gear 5I' is constantly in mesh with a pinion 52 best illustrated in Figure 2 of the drawings, which rotates upon the axis 53 and which causes rotation of the gear 54. 'I'he shaft 53 is supported in any suitable manner as by the partition 50.

A second shaft 55 is mounted in any suitable manner as by the partition 50 and supports a pinion 59 in mesh with the gear 54 and the gear 51 which is rotated with the pinion 59. The gear 51 rotates a pinion 59 mounted upon a shaft 90 which extends downwardly through the spider i supporting a ring of felt 10 or other suitable material. The ring 99 is supported as illustrated in Figures 1 and 4 by a pair of links 1I and a second pair of links 12. The links 1I are pivotally attached at 13 to xed supports 14, while they are pivotally secured at their other end 15 to ears 19 upon the ring 99. The links 12 are pivotally connected at 11 to xed supports 19 and are pivotally secured at their other -end 30 to ears 9| on the ring 99. It will be noted that by this arrangement, the ring 99 remains parallel to the disc 91 at all times, and that the links 1I e and 12 permit the ring to befmoved toward or away from the disc 91. A To actuate the ring 99 toward or away from the disc 91, I provide a pair of links 92 pivoted between ears 33 upon the ring 99 and pivoted at 34 to bell crank levers 95. The levers 35 are pivoted at 39 to the ilxed supports 19 and on the opposite side of their xed pivots 39 are pivoted at 31 to link means 39. The links 39 are secured by pins or other suitable means to a ring 9i which is formed as a part of the collar 92, but is rotatable with respect thereto. The collar 92 is longitudinally slidable upon a shaft 93, but is designed to rotate with the shaft 93. A fixed collar 34 is 21 to move toward low pitch position. It no 75 secured near an end of the lshaft 93 and a spring 95 is interposed between the fixed collar 94 and the slidable collar 92. Governor weights 99 are .secured by pairs of links 91 between the xed colcollar 92 toward the fixed collar 94. This movement will cause longitudinal movement of the ring 9| and the attaching means 90 so as to draw the links. 89 toward the fixed collar 94. This action will tend to pivot the bell crank 85, raising the link 82 and moving the ring 69 upwardly toward the disc 61. If the movement is sufficient, it will cause friction between the felt 10, which is preferably impregnated with oil or other suitable material, and the disc 61, tending to slow down the disc 61 with respect to the speed of rotation of the shaft. I0. Any variation in the speed of rotation between the disc 61 and the shaft I 0 causes rotation of the gear 63, the pinion 62, the gear 6| and the vertical shaft 60. Rotation ofthe vertical shaft 60 causes rotation of the pinion 59, gear 51, pinion 56, gear 64, pinion 52, gear 5|, and pinion 49, which causes rotation of the gear 46 and the bevel gear 44. This in turn causes rotation of the ring 29 bearing the teeth 30, thus acting to vary the pitch of the propeller in a manner to increase the same.

The shaft 93 is mounted between a fixed support 99 and an end support |00, and is provided with a bevel gear cooperating with a similar cooperating bevel gear |02 on a shaft |03. The gear |04 is mounted upon the gear |03 which operates the idle gear |05 which in turn engages the gear |06 on the shaft l0. Rotation of the shaft I0 rotates the gear |06, the gears |05 and |04, shaft |03, and bevel gears |02 and -|0|, to rotate the shaft 93. This causes operation of the governor which controls the movement of the ring 69. The shaft |03 and the fixed supports 99 are secured to the nose plate |01, secured infixed position in the front of the motor. A housing |09 is designed to surround the cylindrical portion II of the shaft I0 and to contain the governor, `the ring 69, and the mechanism for operating this ring; The housing I6 is of course rotatable and rotates in`an aperture |'I0 designed for this purpose.

In order to provide a manual control for varying the pitch of the blades 21, I provide a bell crank I pivoted at I I2 to a fixed support I3. One end of this bell crank is pivotally connected to one of the links 89 at the point II4. A manual control cable ||5 extends through a pivoted lug ||6 on the other end of the bell crank lever- III. By pushing on the control cable |I5, the end of the bell crank lever attached to the cable is pivoted upwardly, pivoting the bell crank in a counter-clockwise direction, causing the bell crank lever 85 to pivot in a clockwise direction, and pulling the ring 89 away from the disc 61 to withdraw friction therefrom. By pulling on the control cable I5, the bell crank lever 85 is moved in a counter-clockwise direction, raising the ring 69 and creating additional friction against the disc 61. Thus when-it is desired to increase the pitch manually, the control cable ||5 is pulled, whereas if it is desired to decrease the pitch, the control cable is pushed inwardly. drawing the ring 69 away from the disc 61. The springs 39 are then free to pivot the blades 21 toward low pitch position.

A spring |I1 is interposed between a nut ||9 on the cable ||5 and the lug I I6 on the lever |I|. If the control cable ||5 is pushed inwardly, the spring ||1 creates a tendency to pull the ring 69 away from the friction disc 61. As the governor operates, the bell crank lever III is moved 1n a clockwise direction by the link 89. This movement compresses the spring ||1 and accordingly the governor must act against the spring ||1 as weil as the spring 95. Accordingly. the governor can operate at a higher rate of speed without forcing the ring 69 against the friction disc 61. Thus as the ship is started from the ground, the control cable I I5 may be pushed inwardly and the propeller shaft I0 will be permitted to act at a higher rotative speed without increasing the pitch of the propeller blades 21.

Similarly, the spring ||1 may operate to provide the opposite function and to provide a tendency to push the ring 69 against the disc 61 if the control cable I5 is pulled outwardly. Thus if it is desired to manually increase the pitcl of the blades to an angle more than would normally be assumed by the blades at a particular speed of rotation of the shaft I0, the control cable 5 is pulled outwardly, accomplishing this result. By pulling the cable ||5 farther out, the head |20 of the cable will 'engage against the lug ||6 to cause the-felt on the ring 69 to engage the friction disc 61 to move the propeller blade into full-feathering position.

'I'he spider I5 is held in place by a nut I2I on the threaded portion ||3 of the shaft I0. A partition |22 parallel to the partition 50 covers the construction of the device. When the speed of rotation of the shaft I0 increases,the gear |06 on this shaft acts through the gears |05 and |01 1| and 12 in a counter-clockwise direction. This to rotate the shaft |03 which acts through the bevel gears |02 and |0| to rotate the governor shaft 93. This increase of speed throws the governor weights 96 outwardly, acting through the levers 91 to move the ring 9| of the collar 92 to the right as viewed in Figure 1. This action acts through the pivot pins 90 to move the links 89 to the right, pivoting the bell crank levers 95 in a counter-clockwise direction and acting through the links 82 to move the supporting links action raises the friction pad 10 into contact with the disc 61, creating a frictional engagement between the disc 61 and the friction material 10 of the stationary friction disc 69.

The disc 61 and the series of gears connected therewith normally rotate without relative rotation together with the shaft I0. As the friction surface 10 tends to slow down the disc 61 and cause this disc to rotate slower than the shaft I0, relative rotation of the various gears is necessary. `A small angular movement of the disc 61 causes an extremely small angular movement of the gear 44 because of the gear train interposed therebetweei-. A slowing down of the disc 61 causes the slowing of the gear 64 connected thereto. which in turn rotates the pinion 62 connected thereto. The pinion 62 rotates the gear 6| which rotates the shaft 60v extending through the spider able with the propeller blades 21. Thus through the train of gears a slight pressure upon the disc This causes rotation of the gear 63 61 tending to slow the speed of rotation of thisdisc will act to rotate the blades 21 axially.

The pressure required to change the pitch of the blades to increase the pitch thereof is dependent upon the resistance by the blades to such rotation. When the friction surface 10 ofthe disc y69 is moved away from vthe disc 61, the springs 39 within the bladestend to rotate these blades toward low pitch. Movement of the blades 21 toward low pitch will normally cause an in.

crease in the speed of rotation of the shaft lil, which in turn will act through the governor in the manner described to increase the pitch of the blades. Thus the angle of the pitch of the blades is greatly dependent upon the speed of rotation of the shaft i and the resistance of the blades to any change in pitch.

In the manual operation the cable connector H is provided to pivot the bell crank l l I to move the link 89 by hand in place of through governor control. The manner in which the links 99 are operated by the governor weights 96 has been described.. 'I'hese links 89 are also attached to the bell crank Hi .which is controlled manually through the cable H5. Y

If it is desired to increase the pitch manually to an angle more than would normally be assumed by the blades at the particular speed of rotation of the shaft I0, the control cable I5 is pulled outwardly, the head thereof pivoting the bell crank III in a clockwise direction, pivoting the links 99 to the right as illustrated in Figure l,

which in turn pivots the bell cranks 85 in a counter-clockwise direction, acting through the links 82 to pivot the supporting links 1I and 12 in a counter-clockwise direction and raising the disc 89 bearing the friction surface 1li into engagement with the disc 61. Thus by pulling on the control cable IIS, the blades may be axially rotated in the same manner as if the speed of rotation of the shaft Il) had been increased. The amount to which the blades 21 may be pivoted by the control cable I i5 is dependent upon the length of time the friction disc 1li is held in contact with the disc 61. -The blades may thus be merely actuated to increase the pitch thereof, or may be moved into feathering position.

Because of the series of gears interposed between the propeller blades and the disc B1, only a small amount of pressure is necessary to vary the pitch. It has been found that oil soaked felt may be used upon the ring 69 to provide the necessary friction, and that such felt will stand up under the necessary pressure. If necessary, other materials may be used, however, to provide the necessary friction between the ring 69 and the disc 61 to act to change the pitch of the blades 21.

In accordance with the patent statutes, I have described the principles of construction and operation of my variable pitch propeller; and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that this is only illustrative of a means of carrying out my invention, and that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A variable pitch propeller comprising a propeller shaft, a blade support mounted thereon, blades mounted on said support, gear means rotatably connecting said blade means to rotate the same axially in unison, a large gear means connected to said gear means, a pinion engaging said large gear means, a gear large relativevto said pinion rotatable with said pinion, a second pinion engaging said last named large gear, a rotatable peller shaft., a blade support mounted thereon,

blades mounted on said support, gear means rotatably connecting said blades to rotate said blades axially in unison, a large gear means connected to said gear means, a rotatable disc encircling said shaft, a series of reduction gears Vconnected to said rotatable connecting means,

said gears and disc normally rotating in a body with said shaft, a stationary friction disc element engageable with said disc, and governor means driven by said shaft moving said friction disc element against said disc upon an increase in speed of said shaft to' create relative rotation be- EDWARD LINEHAN.