US1309489A - Double-gyro inclinometer - Google Patents

Description

L. B. SPERRY.

DOUBLE GYRo INCLINOMTER.

AFPLICATION FILED APR. 1B. l9l8.

1 ,$09,489. Patented July 8, 1919.

, UNITED sTATEs PATENT oEEIeE.

LAWRENCE B. SPERRY, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE SPERRY GY'ROSCOPE COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION 0F NEW YORK.

DOUBLE-GYRO INCLINOMETER.

Specification of Letters Patent.

Patented July 8, 1919.

To all ywlw/rt it may fron/:cru

Be it known that I, LAWRENCE ll. SrEuuY, a citizen of the United States of America, residing at 1505 Albemarle road, Brooklyn, in the county of Kings and State of New York, have invented certain new and useful lmproveuu-,nts in Double-Gyro Inclinometers, of which the following is a specification.

This invention relates to inclinometers, more specifically to inclinometers of the type employing a rotating wheel or top to establish a reference line and especially adapted for use on aeroplanes.

I have discovered that while a rotating wheel or top will maintain its rotational axis substantialy vertical when the aeroplane, or

' other device on which the top is employed,

is turning in azimuth in the same direction as the top is rotating, the rotational axis of the latter drops out of vertical position when the vehicle is turning in the opposite direction. The last mentioned action renders the device unreliable and under the conditions assumed practically destroys its utility.

While the problem presented under the above assumed conditions might be solved by employing a' damping, force impressing or other similar means, it should be n oted that by the provision of any such means the device would lose its chief characteristic, i. e., simplicity. I solve the problem by employing two oppositelyl rotating wheels or tops, so that at least one will furnish a true reference line at all times.

Referring to the drawings in which, what I now consider to be the preferred form of my invention, are shown:

Figure 1 is a plan view of the device constructed in accordance with my invention, the cover of one of the gyroscopes being removed.

Fig. 2 is a cross section on approximately line 2-2 of Fig. 3.

Fig.'3 is a diagrammatic view, partly in section and on a smaller scale, of m invention showing the means used to contlnuously withdraw air from the interior of the casmg.

Fig. 4 is a plan view showing the graduations on cover 8.

Each top is shown as comprising a rotor or flywheel 1, having a heavy ring 2 and a cut-out under portion 3. In the center of the top is a point 4 which supports the top for rotation about a normally vertical axis and at the same time allows the top freedom of movement about both horizontal axes intersecting at said point. lVhile in the common or ordinary form of top the center of gravity is located above the point of support I` prefer to so design the tops, employed in my invention,- that the center of gravity is located very close to but slightly below the point of support 4. By virtue of this design each top stands substantially in neutral or indifferent equilibrium when at rest whereby a long period of oscillation is secured.

Each top is preferably provided with a spindle 5 which acts as a pointer or indicator, and coperates with radial graduations and with circular graduations 7 on the transparent covers 8 to indicate both the angle and direction of inclination of the vehicle on which the instrument is mounted. Each cover is securedwithin a cap 9 threaded into thetop of the casing proper 10 or 10', the joint 10() being tightly packed. Illuminating means such as lamps 70 and 71 may be provided, if desired. Each casing surrounds its rotor and supports the sameK on a post 11 secured to the bottom of the casing. Casing 10, together with companion case 10 are shown as resiliently supported from a ring or frame 12 by means of a plurality of rods 13, 13 and 13 which are adjustably threaded to said frame and locked thereto by lock nuts 14, the casings 'being supported on said posts by springs 15 resting on washers 16 or the like. Preferably a downwardly acting spring 17 is placed above said ring and acts between the cap 18 and the ring so that jars will not affect the4 apparatus. Preferabl three such supporting rods are provided or the gyroscopic device. A bracket 72 secured to ring 12 may be used to attach the apparatus to the aeroplane or other vehicle.

For revolving each rotor I prefer to provide means for continuously withdrawing 'air from the interiorof its casing, relying upon the entrance of air into the casing in a proper direction and location to revolve the rotor. F or this purpose I have provided valves or other openings 18 18" through which the air is exhausted from the casings in any manner, preferably in 'the manner hereinafter descri ed'.

One or more openings shaped in. the form of approximately tangential nozzles 19, 20,

21 and 22, are provided in the casing 10 in the plane of the rotor 2. The rotor in casing 10 is provided with bucket'sor vanes 23 located in the plane of said .nozzle and adapted to receive thejets of air issuing therefrom. Preferably said vanes are formed by incisions in the periphery of the rotor. The casing 10 and its rotor 3 are provided with nozzles 19 to 22 and buckets 23 similar to the corresponding` struct-ure of casing 10 and its rotor 3 except that the former extend in a direction opposite the last mentioned nozzles and buckets. tors 2, 2 will be rotated-in opposite directions.

Each post 11 is shown as comprising a central supporting stem 20 having an axial bore 21 in which is located a spring 22 supporting a rod 23. Said rod is provided adjacent its top with a tapered or concave recess 24 in which the point 4 attached to the top l rests. Preferably said recess is flat at the bottom portion 80 at which point the wall 81 is substantially perpendicular for a short distance.

As above stated I employ a plurality of tops 1 and 1 which are driven in opposite directions as indicated by the arrows in Fig. l. The reason for employing two oppositely rotating tops is, as previously stated, to insure -having at least one of the tops cor` rect at all times. For instance, if the aeroplane on which the apparatus was mounted was turning in the direction of arrow C (Fig. l) top 1, which is shown as rotating in the opposite direction, would have a tendency to flop over, as indicated, while top 1 would remain unaffected. Similarly, if the aeroplane were turning in the other direction, top l would straighter up, while top l would tend to turn over. nShe casings 10 and 10 inclosing the two tops may be formed as one or connected by pipe 50. Each casing may be provided with an outlet valve 18 and 18, which may be con-v nected to the air exhausting device.

For exhausting the air from the casings, I prefer to employ a device 55 somewhat similar to a Venturi tube. Said device may comprise a tubular member with a restricted passage 56 therein, each end of the member tapering outwardly, Fig. 3. If the aircraft is flying in the direction indicated by the arrow a in said figure, the air will flow with great speed through the said tube and restricted passage, thereby reducing the pressure to a marked extent adjacent said passage. At or adjacent said restricted passage is located a second small tube 57 which is connected to the valves 18 and 18 by means of a pipe 58. having a branch pipe 519. Pipe 58 is shown tappe-d into tube Thus the ro- 57 adjacent a restricted passage G0 therein as indicated in Fig. 3, whereby .a double rarefactionlof air, soto speak, is produced. By properly manipulating the valves 18', 18 and a valve 110, provided in the pipe 50 either or both of the tops may be disconnected from the air exhausting device.

In accordance with they provisons of the patent statutes, I have herein described the principle of operation of my invention, together with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering withv the more general results outlined and the invention extends to such use.

Having described my invention, what I claim and desire to secure by. Letters Pat ent is:

l l. An inclinometer for aeroplanes comr1s1n0 a air of omt-su orted g roseo 1c e p e.

rotors having -normally vertical spinning axes and air turbine means for driving said rotors in opposite directions.

2. An inclinometer for aeroplanes comprising a pair of tops, an inclosing lcasing for each top, means for withdrawing air from said casings, oppositely positioned buckets or vanes on the tops and a nozzle adjacent each top connecting .the interior of the casing with the outside air.

' 3. rIhe combination with an aeroplane, of a Venturi tube thereon, a casing connected to said tube, a plurality of tops within said casing, buckets or vanes on said tops and openings through the casing adjacent each top and oppositely directed whereby opposite rotation of the tops is secured.

4. In gyroscopic apparatus, the combination with a plurality of rotors, communicating inclosing means for said rotors, a

plurality of outlets from said casing at least one for each rotor, means for exhausting air through said outlets and an air admitting nozzle foreach rotor.

5. In gyroscopic apparatus, the combination with a plurality of rotors, communicating inclosingmeans for said rotors, a plurality of outlets from said casing, means for exhausting air through said outlets and means for shutting off that portionof the casing adjacent a rotor from a portion of the apparatus adjacent another rotor.

In testimonyI whereof I have affixed my' signature.

LAWRENCE B. SPERRY.

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