US1850011A - Airplane - Google Patents

Description

Mai-ch 15, 1932.

H. A. HICKS I AIRPLANE Filed March 28, 1930 USED INVEN TOR. A 62. A MA.

A TTORNEY.

Patented Mar. 15, 1932 UNITED STATES- PATENT OFFICE HAROLD A. OF DETROIT, MICHIGAN, ASSIGNOR TO FORD MOTOR COMIPANY, OF DEABBORN, MICHIGAN, A CORPORATION OF DELAWARE AIRPLANE Application filed March 28, 1930. Serial No. 439,569.

The objectof my invention is to provide an airplane having a novel type of landing gear especially adapted to preventdamage to the plane if it should nose over while it is land ing. Frequently airplanes, especially those equipped with brakes, will make a landing on soft groundand the running resistance together with the braking resistance will offer such a great restriction to the landing gear that the plane will tip lengthwise or nose over doing great damage. To prevent such nosing over, the landing wheels are usually placed far forwardly of the center of gravity.

For planes not equipped with brakes there is no serious objection to such forward placing of the wheels, but when brakes are to be used on the wheels it is very advantageous to place these wheels only slightly forward of the center of gravity of the plane so that practically the full weight of the plane will act on the brakes to thereby stop the plane in the shortest possible space.

The above type brakes are very eflicient but one serious objection is encountered in their use. This objection arises because the center of gravity of the plane, being almost directly above the wheels, tends to pivot forwardly around these wheels when the brakes are applied so that the nose or front end of the fuselage is forced into the ground with the consequent da mage to the plane.

My invention relates to a landing gear having braking wheels placed substantially below the center of gravity of the plane so that maximum braking efliciency may be obtained therefrom combined with a normally inoperative nose wheel mounted beneath the front end of the fuselage and a normally operative rear wheel mounted beneath the tail portion of the plane. When the plane is taking-ofi and normally landing, the braking wheels and the rear wheel support the weight of the plane, while when the brakes are fully applied the center of gravity shifts forwardly so that the two braking wheels and the nose wheel support the weight of the plane. It

will be seen that at all times the braking wheels are disposed almost directly beneath the center of gravity of the plane so that very efficient braking is always obtained.

It will be understood that there are two positions in which the plane travels on the ground, the normal horizontal position where the two center wheels and the rear wheel are rolling on the ground, and the nosed over position wherein the brakes are applied with the center wheels and nose wheel rolling on the ground.

The structure forming the subject of this application consists of my landing gear having two sets of wheels so placed in relation to the center of gravity of the plane that under certain conditions the plane will be supported in stable equilibrium upon each set; the one set supporting the plane while it is standing still, in uniform motion, or accelerated motion, and the other set supporting the plane while it is slowing down due to the application of the brakes.

\Vith these and other objects in View, my invention consists in the arrangement, construction, and combination of the various parts of my improved device, as described in the specification, claimed in my claims, and illustrated in the accompanying drawings, in which:

Figure 1 shows a side elevation of an airplane constructed in accordance with this invention shown in the nosed over position with the brakes applied, and

Figure 2 shows a front View of a portion of the airplane shown in Figure 1.

Figure 3 shows a side elevation of a portion of an alternate structure having a nose skid in place of the nose wheel shown in Figure 1.

Referring to the accompanying drawings, I have used the reference numeral 10 to indicate generally an airplane fuselage havinga pair of wings 11 secured on either side there of, a rudder l2, and control surfaces 13. A I

pair of engine nacelles 14 extend upwardly from the top side of each wing 11, one on each side of the fuselage 10, and a pair of motors 15 are secured in each nacelle to propel the plane.

I have designated the position of the center of. gravity of the plane by across 16 which it will be noted is near the center of the fuse-- lage beneath the engines 15. I have provided a pair of landing wheels 17, disposed slightly forwardly of the center of gravity of the plane in its horizontal position which are each rotatably mounted at the outer end of struts 18. These struts extend outwardly from the bottom portion of the fuselage to which they are pivotally secured at 23 and swing around this pivot to absorb the landing impact. A pair of compressible struts 19 extend from the outer ends 'of the struts 18 upwardly and are fastened to the under side of the wings 11 to thereby resiliently support the weight of the plane on the wheels 17. A tail wheel 20 is fastened beneath the rear end of the fuselage 10 which may be provided with a shock absorbing element if desired. This wheel is preferably arranged to swing around a substantially vertical axis so that the plane may be maneuvered on the ground. I have provided a brake 22 on each of the wheels 17 which may beoperated by the pilot from within the fuselage the conventional manner.

When the plane is standing, taking-off, taxiing for position, or making a landing without fully applying the brakes, the two wheels 17 together with the tail wheel 20 support the weight thereof. The center of gravity is at this time a slight distance to the rear of the wheels 17 so that the plane is in stable equilibrium upon these three wheels, even though practically all of the weight is carried by the wheels 17. If while the plane is landing it is necessary to fully apply the brakes, very efficient braking is assured due to the great weight placed on the braking wheels. However, when the brakes are applied the center of gravity swings forwardly around the braking wheels a distance depending upon the deceleration produced by the brakes so that as it swings forwardly of the wheels 17 the front end of the fuselage drops toward the ground.

I have provided a nose wheel 21' rotatably mounted beneath the forward end of the fuselage which is in a position to roll against the ground when the plane is thus nosed over to thereby protect the fuselage from damage. As long'as the plane is decelerating sufficient to shift the center of gravity forwardly of the wheels 17 the plane will roll along on the nose wheel 21 and braking wheels 17 Even while rolling in this nosed over position near- 1y all of the planes weight is carried by the braking wheels so that maximum braking may be obtained in either of the planes rolling positions.

' Heretofore, when planes have been equipped withbrakes on the landing wheels, it has been necessary to place these wheels far forwardly of the center of the gravity of the plane so that the application of the brakes would not nose the plane over. It can'be readily seen that the efficiency of these brakes were not high because the center of gravity being far rearwardly of the wheels, a large ortion of the weight of the plane was carried y the rear free wheel. The installation of a brake on the rear wheel is very complicated or the like and still benefit by the structure shown herein. r

Many advantages arise from my improved structure among which may be mentioned that maximum braking of the plane may be obtained at all times without the risk of damage to the plane. provides two rolling positions for the plane,

ing wheels. 7

Some changes may be made in the arrangement, construction, and combination of the various parts of my improved device without departing from the spirit of my invention and it is my intention to cover by my claims such changes as may reasonably be included within the scope thereof.

I claim as my invention:

1. In an airplane having a pair of landing wheels secured beneath its intermediate portion, wheels secured a lesser distance beneath each end of 'said airplane, the center of gravity of the airplane being so positioned that the airplane will be supported in stable equilibrium on the landing wheels and rear and manually operable decelerating means whereby said center of gravity may be shifted to position forwardly of said landing wheels to thereby rock the plane around the landing wheels so as to be supported-by said landing wheels and forward wheel.

2. In an airplane having a pair of landing wheels disposed beneath its intermediate portion, wheels secured a lesser distance beneath each end of-said airplane, said airplane having its center of gravity so positioned that when the plane is rocked around the landing wheels said center Will shift in the rocking plane from one side of the landing wheels to the other side, and brakes operating through said landing wheels whereby the center, of gravity may be operably shifted from one of its positions to the other.

3. In an airplane of the high wing monoplane type, engines mounted upon the upper surface of said wing whereby the center of Further, my landing gear in each of which the center of gravity of the plane is substantially directly above the brakthe landing wheels the center of gravity will .between said landing wheels and center of gravity so that said center of gravity may be rocked forwardly and rearwardlyof the landing wheels to provide two positions of stable equilibrium for said airplane, and manually operable brakes on said landing wheels whereby said center of gravity may be shifted from one of said positions to the other.

4. An airplane having a pair of landing wheels disposed beneath its intermediate portion, supporting means secured a lesser distance beneath each end of said airplane, said airplane having its center of gravity so positioned that when the plane is rocked around shift in the rocking plane from one side of the landing wheels to the other side, and brakes operating through said landing Wheels whereby the center of gravity may be operably shifted from one of its positions to the other position.

5. An airplane having a pair of landing wheels disposed beneath its intermediate portion, a landing wheel secured a lesser distance beneath the rear portion of said airplane, a skid secured a lesser distance beneath the forward end of said airplane, the center of gravity of the airplane being so positioned that when the plane is rocked around the landing wheels the center of gravity will shift in the rocking plane from one side of the landing wheels to the other side, and brakes operating through said landing wheels whereby the center of gravity may be operably shifted from one of its positions to the other position.

6. An airplane having a pair of landing wheels secured beneath its intermediate portion, supporting means secured a lesser distance beneath each end of saidairplane the supporting means at the forward end of the plane comprising a skid secured directly to the bottom of the fuselage, and the center of gravity of the airplane being so. positioned that the airplane will be supported in stable equilibrium on the landing wheels and rear support during normal taxiing of the plane,

and manually operable decelerating means I whereby said center of gravity may be shifted to position forwardly ofsaid landing wheels to thereby rock the plane around thelanding wheels so as to be supported by the landing wheels and said skid.

March 22, 1930.

HAROLD A. HICKS.

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