US2573854A - Airplane engine cooling arrangement - Google Patents

Description

Nov. 6, 1 51 K. F. LOVEJOY ET AL 2,573,354

AIRPLANE ENGINE COOLING ARRANGEMENT Filed Feb. 15, 1946 v 4 Sheets-Sheet l W EK S Q L m "1 I; m

fic'wz'd Ban'i eaf gnneihilovejoy 44M; m rm Nov. 6, 1951 K. F. LOVEJOY ET AL 2,573,854

AIRPLANE ENGINE COOLING ARRANGEMENT Filed Feb. 15, 1946 4 Sheets-Sheet 2 Nov. 6, 1951 K. F. LOVEJOY ET AL AIRPLANE ENGINE COOLING ARRANGEMENT 4 sheets-sheet 3 FldFb 15 1946 -INVENTORS David Bczrzfeaf fi neflz 10122 0 ATTORNEYS N 1951 K. F. LOVEJOY ET AL 2,573,854

AIRPLANE ENGINE COOLING ARRANGEMENT v Filed Feb. 15, 1946 Y 4 Sheets-Sheet 4 M/l/[A/TOAS fiavid BarrPeaZ Kenneth Flavejoy Patented Nov. 6, 1951 AIRPLANE ENGINE COOLING ARRANGEMENT Kenneth F. Lovejoy, Pittsburgh, and David Barr Peat, Dravosburg, Pa.

Application February 15, 1946, Serial No. 647,810

3 Claims.

This invention relates to airplanes, and particularly to an airplane designed either to take off from the surface of water, or to an amphibious plane which may take 01f and land either on water or on land.

The airplane of the present invention is intended primarily as a light craft for use by individuals, and has for its object to overcome many of the disadvantages attendant in smaller seaplanes as presently constructed.

Commonly the small seaplane or amphibious plane is merely an adaptation of the conventional land plane to receive pontoons. Commonly it has the engine and propeller at the nose of the fuselage, has the wings across the top or near the bottom of the fuselage, and has the fuselage extending back to the tail of the plane. Pontoons are arranged at each side of the fuselage, sometimes depending directly from the wings, and sometimes being attach d to the fuselage itself.

The nose of the plane, when so constructed, has to be high enough above the water so that even in very choppy water the propeller will not hit the waves. This requires that the fuselage be relatively high above the pontoons so that it is awkward to get into the plane. Moreover, it is impractical to use with such an amphibious plane the so-called tricycle landing gear where there is a front wheel forwardly at the middle of the fuselage, and two landing wheels, one built into each of the two pontoons, because the front of the fuselage is so far above the water that the forward middle wheel requires an excessively long strut which is difficult to brace. Another difficulty is that while the fuselage is high enough oif the water so that the propeller at the nose will clear the waves, the wings being either against the top of the fuselage, or being underslung from the bottom of the fuselage, and the tail are so close to the surface of the water that the wings or tail are likely to bump against small boats and cruisers that are frequently moored around places where such planes are used, or they are likely to bump against the docks and pilings which are provided around such places. Additionally, as now constructed and arranged, the pilot has difficulty in maneuvering the ship up to a wharf against a head wind when the propeller is at the front of the ship because, after cutting the engine, the wind tends to drift the plane away from the shore, and with the propeller at the front, the engine must be stopped before the point of landing is reached. Hence there is always a tendency to come in too fast or to misjudge the distance.

The present invention provides a light plane which is designed to overcome these difficulties,

and which, in addition, provides for more effective cooling of the engine than has heretofore been possible with planes of this type, particularly where, as with the present invention, the propeller is at the rear instead of forwardly of the wing.

In general the present invention provides an arrangement wherein the bottom of the fuselage is at or near the level of the top of the pontoons, so that it is close to the water and so that the pilot can readily step from the pontoons to the fuselage. This enables a tricycle landing gear to be used with the middle front wheel on the bottom of the front of the fuselage requiring only a short strut.

A high wing elevation is provided by supporting the wing on a column or structure at the top of the'fuselage well above the top of the fuselage so that even though the fuselage is close to the water the wings are high enough to clear many of the obstructions that interfere with the free use of smaller planes. Twin booms extend from the rear edge of the wing at each side of the fuselage to support the tail structure and rudders, while the engine is supported above the fuselage and at the rear edge of the wing. A duct or flume is formed over the top of the fuselage under the wing in such manner as to provide fire walls to enclose the engine from the rest of the plane structure, and at the same time provide a very effective way of cooling the engine.

Because of the fact that the propeller is at the rear of the plane and is at the high level of the wing, it is entirely clear of waves or rough water,

as is also the tail assembly, and the plane can be taxied up to a landing wharf under power because it is unnecessary to stop the propeller entirely in coming into a landing.

Additionally the relation between the pontoons and the fuselage enables the pontoons to be sprung or yieldably supported at the bottom of Our invention may be more fully understood byreference to the accompanying drawings, which illustrate a present preferred embodiment of our invention, and in which: a

Fig. l is a side elevation of a plane constructed according to our invention;

Fig. 2 is a front view thereof;

Fig. 3 is a top plan view;

Fig. 4 is a longitudinal section on a larger scale on the center line of the plane showing the disposition of the engine and the flume arrangement by which air is'conducted to the engine;

Fig. 5 is a fragmentary top plan view of a modified support for the fuselage on the pontoons; and

Fig. 6 is a front elevation showing the mod= ification of Fig. 5.

In the drawings, 2 designates the fuselage of the plane. It is provided with a cabin 3 that increases forwardly in height. The cockpit is located at 4 and is provided with a windshield 5 and sliding side windows 6, the windows 6 sliding to the rear so as to enable one to step into the cockpit from the pontoon. Also the plane can be operated with these windows open or closed, as desired. The cockpit being, so far forward, the operator can see the ground or water without obstruction when coming into a landing, which is of considerable advantage, especially for the novice, or where the landing has to be maneuvered among small boats or other obstructions.

Along each side of the fuselage is a pontoon l. The tops of the pontoons are just below the level of the bottom of the fuselage, and the fuselage is supported on the pontoons by two transverse struts 8. In Figs. 1 to 3, these struts 8 are illustrated as being rigid cross members,.and there is provided in addition conventionally arranged diagonal struts 9 for completing the suspension of the pontoons from the fuselage.

However, the arrangement shown in Figs. 5

and 6 may be used, in which cross members sa are transversely extending leaf springs of substantial width, or the terminal portions of which at least are leaf springs, or springs of other construction may be operatively interposed. This provides a yieldable connection between the pontoons and the fuselage, and the width of the springs is sufficiently great to enable the torque which is set up when the plane is landing or taking off to be effectively resisted. The additional diagonal braces 9 of Figs. 1 to 4 may or may not be used. Preferably they are eliminated. The ends of the springs 8a are attached directly to the tops of the pontoons, and a plate 8b secures the springs to the fuselage.

The pontoons themselves are of standard construction and depending upon whether the plane is to be amphibious or merely a seaplane, may be provided with retractable Wheels Ill. The construction and arrangement of the wheels in the pontoons is well known and forms no part of the present invention. However as hereinbefore indicated, the wheels I!) are not supported on springs in the pontoons so that with present constructions, in making a landing there is nothing to absorb any of the shock, whereas with the arrangement shown in' Figs. 5 and 6, by springing the pontoons from the fuselage, an arrangement for absorbing shock in landing on either water or land is provided.

The wing of the plane is designated II. It is carried and supported at a substantial elevation above the top of the cabin or fuselage, there being suitable structural members Ila for holding the wing in elevated position above the fuselage.

As best shown in Fig. 3, the trailing edge of the wing at the middle of the plane is cut back as indicated at l2, providing clearance for the tips of the propeller l3. The engine designated generally as M is built into the under side of the win immediately forwardly of the propeller. An air-cooled engine having four horizontal cylinders arranged in two opposed pairs is conventionally illustrated, this being a type of motor commonly used for light plane construction. The crank shaft of the engine of course extends in a fore and aft direction with the propeller on the end of the crank shaft.

According to our invention, a sheet metal housing is formed under the mid-section of the wing above the fuselage at the center of the plane, the housing being designated generally as I5. It has a downwardly andforwardly curved back portion l6 (see Fig. 4), two spaced side plates I1, the

all

75 in that the fuselage is close to the level of the side plates ll rising vertically from the top of the fuselage and being outwardly flared where they merge into the wing structure. Between these side plates 11 is formed a duct or flulne at the top of which is a curved sheet metal plate l8, which turns downwardly in front of the engine. A metal grill l9 covers the front of the opening or duct to prevent birds or other objects from entering the flume.

The mid section of the wing extends back over the engine and is spaced above it, there being a relatively wide flattened space [6a nearly the full width of the mid section of the wing above the engine, which space opens rearwardly. The inlet for cooling air is thus below the engine while the outlet is above and to the rear. This is conducive to a natural connective flow so that even with the engine idling and with very little suction from the propeller, there is effective cooling of the engine. This most effective condition for cooling the engine also prevails in flight when the forced circulation of air entering the front of the duct is compatible with the connective flow, with the rising warm currents of air moving always away from the engine, whereas in most cases, the air is forced oppositely to natural draft conditions.

The duct so formed may be used instead to house a jet or turbine motor, where such means of propulsion is used in lieu of a conventional internal combustion engine.

The housing, while serving to enclose the engine and provide side walls separating it from the rest of the plane, may also enclose the structural elements which are more or less conventionally shown, connecting the wing with the fuselage to provide an overall streamlined appearance, this structure being designated Ila in Fig. 4.

Merging into the wing at each side of the fuselage and extending rearwardly therefrom is a boom, the twin booms being each designated 20. A horizontal fin 2 l is located between these booms, and there is a flap 22 at the rear of each fin 2|. At the ends of the booms there are also vertical rudders 23. The arrangement of the tail assembly with twin booms is in itself not novel, but by elevating the wings above the fuselage and providing the twin booms, the tail assembly is also elevated an adequate distance above the water to facilitate maneuvering around small craft and docks. braced to the end of the fuselage by bracing struts 24.

From the foregoing description, it will be seen that the present invention provides an aircraft of light design, useful with pontoons, and especially useful with an amphibious landing gear,

The tail assembly may be top of the pontoons, and the front wheel of the tricycle landing gear is secured to the front of the fuselage by a short strut. This is best shown in Fig. 2, where the single front wheel is designated 25, and the strut 26 is secured to the fuselage forwardly of the cockpit. Also, by reason of the elevation of the wing above the fuselage, provision is made for the propeller, cooling the engine, clearance is provided for the propeller, and the wings and tail are elevated to a height above the water level, where they are less likely to dam-age or contact wharves, piling, or small craft.

Also the arrangement provides a well-balanced and aero-dynamically good construction. The cockpit is forwardly of the wing, and the weight of the pilot or pilot and passenger thus tends to counterbalance the weight of the engine which is to the rear of the longitudinal center of the wing. A considerable storage compartment is provided back of the cockpit where luggage and supplies may be placed, with this load more or less neutrally disposed in reference to the transverse axis of the plane. At the same time, the cockpit is best disposed for access and for vision. The suspension of the fuselage well below the wing with the engine at wing level lends stability to the plane in rough air, more so that if the wing were not elevated above the fuselage.

Finally, by having the bottom of the fuselage on substantially the level of the top of the pontoons, weight is eliminated in the struts required to suspend or connect the pontoons to the fuselage, and it is possible as described in connection with Fig. 6, to compactly operatively interpose springs such as a flat leaf spring as shown between the pontoons and the fuselage to absorb shock in landing or in going over rough water or ground.

While we have illustrated and described one particular embodiment of our invention, it will be understood that various changes and modifications may be made in the construction within the contemplation of our invention and under the scope of the following claims.

We claim:

1. In an airplane having a fuselage with a cockpit and a wing supported in spaced relation above the fuselage, means projecting upwardly from the top of the fuselage and rearwardly and above the cockpit and under the mid section of the upper surface of the wing providing a fore and aft extending duct, the rear end of the duct turning upwardly, an engine under the upper surface of the wing over the top of the duct, and a rearwardly opening chamber under the upper surface of the middle Wing section above the engine and communicating with said duct, the front of the duct being open.

2. In an airplane having a fuselage and a wing supported in spaced relation above the fuselage, means above the fuselage and under the mid section of the upper surface of the wing providing a fore and aft extending duct, the rear end of the duct turning upwardly, an engine under the upper surface of the wing over the top of the duct, a rearwardly opening chamber under the upper surface of the middle wing section above the engine and communicating with said duct, the front of the duct being open, said duct being comprised of spaced side plates merging into the under side of the wing, a rearwardly and upwardly curved end plate, and a cover plate under the middle wing section that slopes downwardly at its rear end to a plane below the engine and to a point in front of the rear plate to thereby form the upwardly extending rear portion of the duct.

3. In an airplane having a fuselage with a cockpit, a structure extending upwardly from the fuselage above the rear of the cockpit, a wing supported at the top of said structure rearwardly and above the cockpit whereby the wing is spaced above the fuselage, said structure constituting an air duct extending in fore-and-aft direction above the fuselage and passing through the rear portion of the wing, said duct being open at the front end, an engine at the rear of the end in said duct, the engine being so located in the duct that the entire current of air flowing through the duct flows over the engine, said engine being located adjacent the trailing edge of the wing and having a propeller shaft with a propeller thereon at the rear edge of the wing.

KENNETH F. LOVEJOY. DAVID BARR PEAT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,394,630 Loening Oct. 25, 1921 1,441,563 Dornier Jan. 9, 1923 1,508,366 Klemm Sept. 9, 1924 1,551,983 Dornier Sept. 1, 19 5 1,603,304 Zimmermann Oct. 19, 1926 1,648,818 Mannick Nov. 8, 1927 1,705,896 Booth Mar. 19, 1929 1,811,550 Loening June 23, 1931 1,860,545 Loening May 31, 1932 2,035,019 Osborn Mar. 24, 1936 2,076,398 Carden Apr. 6, 1937 2,110,516 Weick Mar. 8, 1938 2,177,499 Schairer Oct. 24, 1939 2,196,946 Stone Apr. 9, 1940 2,396,189 Millar I Mar. 5, 1946 FOREIGN PATENTS Number Country Date 516,928 Germany Jan. 29, 1931 677,448 Germany June 26, 1939 462,164 France Nov. 15, 1913

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