US1857036A

US1857036A - Adjustable propeller

Info

Publication number: US1857036A
Application number: US352255A
Authority: US
Inventors: Wisk Walter
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-04-03
Filing date: 1929-04-03
Publication date: 1932-05-03
Anticipated expiration: 1949-05-03

Description

May 3, 1932. w. WISK ADJUSTABLE PROPELLER Original Filed April 3, 1929 2 Sheets-Sheet May 3, w. w s

ADJUSTABLE PROPELLER 2 Sheets-Sheet Original Filed April 3, 1929 Final!!! Patented May 3, 1932 UNITED STATES WALTER WISK, OF NEW BRITAIN, CONNECTICUT ADJUSTABLE PROPELLER Application filed April 3, 1929, Serial No. 352,255. Renewed September 28, 1931.

erator at will, yet former devices of this type have had many disadvantages. In all of these devices there have been heretofore members extending out from the body of the device and in front of the propeller. These members are subjected at all times to the danger of being struck by flying objects and are bulky and unsightly.

The object of this invention is to provide 1 a new and improved means for accomplishing this purpose. The whole device is simple and compact, and is centered around the shaft which carries the propeller in a position to the rear of the propeller. In this way the whole may be enclosed in the fuselage of the plane and is thus completely protected from flying objects and from exposure to weather conditions. The compactness of the device also makes it stronger and less apt to get out' of order.

The invention accomplishes its objects in a new and improved manner unknown in former devices of this kind.

In the past, propellers have ordinarily been made insuoh a manner that the pitch of the 5 blades is the same under all conditions. However, there are many disadvantages to such constructions. For instance, when the air pressure on the blades is suddenly increased, as when the plane turns into a strongwind,

40 the load on the motor is greatly increased. These great variations in load affect unfavorably the action of the motor and decrease both its wearing. qualities and its efficiency. If this change of load can be avoided, the life of the motor will be increased "and its operation will be surer and smoother. Yet this must be accomplished without disconnecting the shaft/on which the propeller is mounted from the motor. Also, the pitch of the blades must be changed automatically, so as not to de-- automatic adjusting means.

The invention consists of blades mounted so that they can be turned to vary the pitch. A spring pressed collar is so connectedto the blades that it tends to increase the pitch of the blades, while the blades themselves are unbalanced, that is, the surface upon one side of the axis is greater than on the other side. 55

Thus air pressure on the blades tends to turn them to a point of lower pitch, while the spring tends to turn them to a point of higher )itch. In addition, means are provided for adjusting the tension of the spring so as to 7 increase or: decrease the pitch of the blades under the same pressure.

Further objects of my invention, and the invention itself, will become apparent from a study of the following description when taken in connection with the accompanying drawings which form a part of this applicationJ In the drawings Fig. 1' is a top plan view of the device.

Fig. 2 is a cross-section on. the line 22 of Fig. l.

Fig. 3 is a cross-section on the line 33 of Fig. 1. j

'Fig. 4 is a cross-section on the line 44 of 35 Fig. 1.

' Fig. 5

is cross-section of the locking .means',

Referring to the various figures of the peller, mounted for turning in the-sockets 4 on the housing 6. The base portions of-the blades are cylindrical, and fit intobores in the sockets 4: and are thus rotatablein the sockets. The bores extend slightly into the housing 6 as shown. The blades are un-' balanced, that is, the surface upon one side of the axis of the cylindrical base portions is larger than on the other side. As the blades are unbalanced on the same side, it is clear 1 0 that air pressure will tend to turn the blades in opposite directions in the sockets 4. To prevent longitudinal movement of the blades I- provide circumferential grooves 8 in the base portions of the blades and set screws 10 -passing through threaded apertures in the .tion is screw-threaded. The housing 6 has a square aperture therein which fits on the squared portion of the shaft and rests against shaft. A- nut 18 is screwed on the threaded portion of the shaft and bears against the housing 6 so as to hold it in place on the shaft.

Upon the intermediate portion of the shaft is a sleeve 20, slidable longitudinally on the shaft but keyed to said shaft so as to rotate therewith. A key 22 on shaft 12 extends through a slot 24 in sleeve 20 and projects beyond the sleeve. Slidably mounted on the sleeve justback of the housing 6 is a collar 26, which has a keyway 28 for the projecting portion of the key 22. Thus the collar 26 is slidable. on the sleeve 20, which is in turn slidable on the shaft 12, yet all three will rotate together upon rotation of" the shaft. In

. the forward face of the collar 26 and in the rear face of the housing 6 are'long

narrow slots

30 and 32 in planes perpendicular to the axis of the blades. The slots in the housing pass just behind the bases of the blades connecting with the ends of the bores in which the blades are mounted. Links 34 moving in these slots connect the collar 26 to theblades 2 (see Fig. 2). These links are pivotally mounted in the slots 30 in the collar by pins 36, and are pivoted at their other ends on eccentrically mounted pins 38 in the bases of the blades. These pins are mounted in different positions in the bases of the blades, one above the horizontal plane through the, center of the bases, and the other below that plane, at points symmetrical with respect to the plane. Thus it will be seen that movement of the collar 26 will turn the blades by erator from moving thesleeve by the to the sleeve and a part 44 surrounding the part 42 and rotatable onthe part 42 by ball bearings 46. Thus while part 42 rotates with the sleeve and shaft, part 44 can remain stationary. The bearings are so arranged howinner part 42 of the collar 40, so that the spring rotates with the shaft, sleeve and col- .lar 26. a shoulder 16 formed by the reducing of the Means 56 are provided for holding the sleeve 39 in the position to which it is adjusted by the handle 52 (see Fig. 5). This locking means consists of a tubulaiymember .presses upon the head of the memberto urge it into locking position. The other end of the spring rests against a cap member 66 screwed into the end of the tubular member 58. This gives an impositive detent which will hold the sleeve 39 in any position to which it may be moved without preventing the o handle 52.

The operation of the device is as follows: Vhen the motor is started and reaches a certain speed, the pressure on the blades of the propeller increases, but as the surface on one side of the axis of the blade is greater than the surface on the other side, the pressure is also greater, and the blade tends to turn in the socket. This is made possible. by the use of the links'34, collar 26 and spring 54. As the blades tend to turn in opposite directions, both tend to move the collar 26 backward or away from the housing 6. This movement is resisted by thespring 54, and when the forces on the blades and the force of the spring are in equilibrium there will be no movement of the blades and the motor will run at a constant speed. Suppose now, however, the plane turns into a strong wind. In

.the old type of plane, the result would be a slowing down of the motor due to the increased resistance to the propeller.

In the present device, however, this in; creased resistance increases the-force on the blades and turns the blades to a position where this force and consequently the load on the motor will again be in equilibrium with the force of the spring 54. This will be done practically instantaneously as the pressure increases and thus the speed of the motor remains almost constant. in load to which motors of this type are generally subjected is thus avoided and the life and efiiciency of the motor will be greatly invice thus gives the benefit of automatic adjustment depending on the load on the motor, and at the same time allows some arbitrary adjustment to meet special conditions. In addition, the device is simple, strong, and cheaply manufactured. There are few parts which can get out of order. The whole mechanism is very compact and is concentrated about the shaft of the propeller, so that the whole is enclosed within the fuselage of the plane. In this way any danger of injury by flying objects is avoided.

While I have described one embodiment of my invention, I wish it to be understood that Various changes may be made therein Within the scope of the appended claims.

I claim: 1. In apropeller, a shaft, a plurality of blades mounted to rotate with said shaft, the longitudinal axes of said blades being fixed relative to said shaft, said-blades being adapted to be turned to a lower pitch about their longitudinal axes by the pressure of air thereon, a collar movable longitudinally of said shaft, means for varying the pitch of said blades upon movement of said collar, a second collar movable longitudinally of said shaft, a spring between said collars for urging said first named collar in a direction such as to increase the pitch of the blades, and

- means for moving said second-named collar to vary the tension of said spring.

2. In a propeller, a shaft, a housing fixedly mounted on said shaft, blocks on said housing having circular bores therethrough perpendicular to said shaft, blades having cylindrical bases, said bases being mounted in said bores and being adapted to turn therein, said blades being unbalanced with respect to their longitudinal axes, slots in said housing perpendicular to the axis of said bores and meeting said bores, a sleeve slidably but nonrotatably mounted on said shaft, a collar slidably but non-r-otatably mounted on said sleeve, links pivoted to said collar, pins eccentrically mounted in the ends of the bases of the blades, said links moving in the slots in said housing and being pivoted to said pins, said pins being set on opposite sides of a horizontal plane through the axes of said bases, whereby movement of said collar will The large changes turn said blades in opposite directions, a sec- 0nd sleeve slidable on said shaft, a second collar fixed on said second-named sleeve, a coil springbetween said collars surrounding said sleeves and shaft.

3. In a propeller, a shaft, a housing fixedly mounted on said shaft, blocks on said housing having circular bores therethrough perpendicular to said shaft, blades having cylindrical bases, said bases being mounted in said bores and being adapted to turn therein, said blades being unbalanced with respect to their longitudinal axes, slots in said housing perpendicular to the axis of said bores and meeting said bores, a sleeve slidably but nonrotatably mounted on said shaft, a' collar slidably but non-rotatably mounted on said sleeve, links pivoted to said collar, pins ec- -centrically mounted in the ends of the bases of the blades, said links moving in the slots in said housing and being pivoted to said pins, said pins being set on opposite sides of a horizontal plane through the axes of said bases, whereby movement of'said collar will turn said blades in opposite directions,

. a second sleeve, slidable on said shaft, a second collar fixed on saidsecond-named sleeve, a coil spring between said first and secondnamed collars surrounding said sleeves and shaft, manually operable means for moving said second-named sleeve, and means on said second-named sleeve engaging said shaft to hold said sleeve impositively from movement with respect to said shaft.

at. In a propeller, a shaft, a housing fixedly mounted on said shaft, blocks on said housfiing having circular bores therethrough perpendicular to said shaft, blades having cylindrical bases, said bases being mounted in said bores and being adapted to turn therein, said blades being unbalanced'with respect to their longitudinal axes, slots in said housing perpendicular to the axis of said bores and meeting said bores, a sleeve slidably but nonrotatably mounted on said shaft, a collar slidably but non-rotatably mounted on said sleeve, links pivoted to said collar, pins eocentrically mounted in the ends of the bases of the blades, said links moving in the slots in said housing and being pivoted to said pins, said pins being set on opposite sides of a horizontal plane through the axes of said bases, whereby movement of said collar will turn said blades in opposite directions, a second sleeve slidable on said shaft, a second collar fixed on said second-named sleeve, a coil spring between said first and secondnamed collars surrounding said sleeves and shaft, a cylindrical member rgtatably but non-slidably mounted on said second named collar, said member having a peripheral groove therein, a bifurcated member having forks thereon, said forks engaging said groove, manually operable means for moving said bifurcated member to move said secondnamed sleeve, and means on said secondnamed sleeve engaging said shaft to hold said sleeve impositively from movement with respect to the shaft.

In testimony whereof, I have hereunto set m si ature.

y gn WALTER WISK.