Title:
MODEL AUTO-GIRO
United States Patent 3791067


Abstract:
Four configurations of a model auto-giro are disclosed with appropriate methods and means of control for each configuration. Two configurations utilize a pivoting stabilator and a fixed rotor shaft and permit the auto-giro to take off, ascend, loop, descend and land, but do not permit it to hover. Two further configurations utilize a fixed horizontal stabilizer and a tiltable rotor shaft, the combination of which permit the model auto-giro to perform all the flight maneuvers of the first two configurations and permit it to hover also. Methods and means for controlling each type of configuration by captive control lines and confining them to circular flight paths are disclosed. Methods and means for remotely controlling each type of configuration by radio controls permitting free flight are also disclosed.



Inventors:
GUTTMAN M
Application Number:
05/264629
Publication Date:
02/12/1974
Filing Date:
06/20/1972
Assignee:
GUTTMAN M,US
Primary Class:
International Classes:
A63H27/04; A63H27/133; (IPC1-7): A63H27/12
Field of Search:
46/74R,75,77
View Patent Images:
US Patent References:
3375605Model plane flight control device1968-04-02Gallagher
3108641Helicopter control system1963-10-29Taylor
2638707Remote-controlled model helicopter1953-05-19Baker



Primary Examiner:
Mancene, Louis G.
Assistant Examiner:
Cutting, Robert F.
Attorney, Agent or Firm:
Cannon, James J.
Claims:
I claim

1. In a model rotary wing aircraft comprising;

2. In the model rotary wing aircraft as defined in claim 1 wherein said aerodynamic control means comprise;

3. In the model rotary wing aircraft as defined in claim 2 wherein said means for operator control comprise:

4. In the model rotary wing aircraft as defined in claim 3, wherein said operator control means comprise an additional control line for operation of the throttle of said engine.

5. In the model rotary wing aircraft as defined in claim 1 wherein said means for providing aerodynamic control comprise;

6. In a model rotary wing aircraft comprising:

7. In the model rotary wing aircraft as defined in claim 6 wherein said aerodynamic control means comprise:

8. In the model rotary wing aircraft as defined in claim 7 wherein said means for providing operator control comprise:

9. In the model rotary wing aircraft as defined in claim 8, wherein said operator control means comprise an additional control line for operation of the throttle of said engine.

10. In the model rotary wing aircraft as defined in claim 6, wherein said aerodynamic control means comprise:

Description:
BACKGROUND OF THE INVENTION

This invention relates to models of rotary wing aircraft and more particularly to models of aircraft capable of both vertical and horizontal flight, commonly known as auto-giros, and methods for controlling said models by means of captive control lines and radio controls to simulate the flight characteristics of an actual auto-giro aircraft.

An auto-giro is a rotary wing aircraft with a free-turning rotor, which is caused to auto-rotate from the flow of air past the rotor when the craft is drawn forward by an engine-driven propeller, as in the case of a conventional airplane.

The prior art discloses numerous patents covering model airplanes and helicopters, and methods of controlling said models. It also discloses several patents, namely U.S. Pat. Nos. 2,110,563; 3,149,802; and 3,588,082; disclosing various types of passenger carrying auto-giros. However, no model auto-giro has been found in the prior art.

The principal design problem for a successful model auto-giro is maintenance of aerodynamic stability in flight, especially at low flight speeds and during hovering. This problem is especially critical for auto-giro models utilizing captive control lines. The use of captive control lines is substantially less expensive than the use of radio controls, but poses significantly greater control problems for the model auto-giro. With captive control lines it is essential that tension be maintained on control lines at all times, especially during slow flight and hovering. The first two configurations disclosed in this specification utilize a number of novel techniques which in combination are able to maintain the required tension. The second two configurations disclosed utilize variations on these techniques adapted to the requirements of radio-controlled operations.

SUMMARY OF THE INVENTION

This invention relates to gasoline-powered model auto-giros and methods for the control of said models in flight. Each model utilizes a gasoline-powered engine mounted on the fuselage driving a propeller to power the model auto-giro. Pitch control means are provided to affect changes in altitude and means for controlling the direction of flight are included.

Four alternate configurations of a model auto-giro and four alternate control methods for the configurations are disclosed. The first two methods of control utilize captive control lines, while the second two utilize remote radio-controls. In the first alternate configuration, the auto-giro is controlled by a two line flexible cord held by the operator, confining the auto-giro to a circular flight path. These control lines in turn operate a bellcrank lever connected to a pivoting stabilator. By pivoting his hand, either to the left or right or up or down, the operator can control the attitude of this stabilator and enable the auto-giro to take-off, ascend, descend, loop and land. The second alternate is similar to the first, except that it utilizes a fixed horizontal stabilizer and a tiltable rotor shaft. In this configuration the pivoting of the operator's hand causes the bellcrank lever to engage the tiltable rotor linkage, tilting the rotor shaft forward or rearward. This tilting of the rotor shaft enables the auto-giro to take-off, ascend, loop, descend, land and also hover. This second configuration permits the auto-giro to hover as well as perform all the flight manoeuvres of the first alternate.

The third and fourth configurations are similar to the first and second respectively except that these configurations of the model auto-giro are adapted to radio controls, and the control methods permit relatively free flight of the model auto-giro unconfined to a circular flight path, that is, the model auto-giro may fly to the left or right or in any direction within the range of the transmitter signal.

All alternate configurations may be equipped with a throttle control consisting of either an additional control line or an additional radio channel and servo motor. All alternate configurations may also be equipped with additional auxilliary fuel tanks for extended operation.

It is the principal object of this invention to provide a gasoline-powered model auto-giro capable of simulating the flight of full size auto-giros.

It is a further object of this invention to provide a method for the control of a model auto-giro by captive control lines.

It is another object of this invention to provide a method for remotely controlling the operation of a model auto-giro.

It is another object of this invention to provide a model auto-giro of extremely simple construction and very inexpensive to manufacture or build.

It is still a further object of this invention to provide a model auto-giro capable of hovering flight, whether captive or under remote radio control.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a schematic side elevational view of a model auto-giro having captive control lines according to the invention;

FIG. 2 is a schematic bottom view of the auto-giro in FIG. 1;

FIG. 3 is an enlarged sectional view of a portion of the rotor shaft with rotor blades cut away showing the relative position of the blade mountings;

FIG. 4 is a schematic front view of the auto-giro Of FIG. 1;

FIG. 5 is a schematic front view of an alternate version of the auto-giro of this invention having a tiltable rotor shaft;

FIG. 6 is a schematic bottom view of the auto-giro of FIG. 5;

FIG. 7 is a schematic front view of the auto-giro of FIG. 5;

FIG. 8 is a partially cut-away view of a portion of the rotor shaft of the auto-giro of FIG. 5;

FIG. 9 is a schematic side elevational view of the auto-giro of FIG. 1 modified to show adaptations for radio control.

FIG. 10 is a schematic side elevational view of the auto-giro of FIG. 5 modified to show adaptations for radio controls.

FIG. 11 is a schematic view of an operator radio unit.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more particularly to the drawings, the first configuration of the model auto-giro of this invention is designated 20 in FIG. 1. The auto-giro 20 comprises a fuselage 21 and integrally formed therewith a rudder 22, and a rotor mast 23 adapted at its top to receive a rotor 24 and two front wheel extenders 25, 26 or spring wire wheel extenders. Rudder 22 is permanently set at a fixed angle 27 to the fuselage 21, as illustrated in FIG. 2. A model gasoline powered internal combustion engine 28 having a puller propeller 29 is mounted on the front of the fuselage 21. Wheels 30, 31 are mounted on the front wheel extenders 25, 26. A single small wheel or skid 32 is mounted at the rear of the fuselage. All wheels are driven only by friction created by the forward movement of the auto-giro on the ground. A stabilator 33 is pivotally mounted to the rear of the fuselage, its trailing end pivoting through an arc 34. The rotor 24, which may be of one-piece construction, comprising the blades 35, 36, connected to a circular hub 37, is rotably mounted on top of rotor mast 23, and held in position by a retaining screw 38 whose elongated shank serves as a rotor shaft 38a and whose head 40 serves as a retainer. A thin-walled tubular bearing 39 is placed within hub 37 to reduce wear on the hub. Utilizing the screws head 40 a thrust bearing 41 may be inserted between the hub 37 of the rotor 24 and the screw head 40 to reduce friction and permit rotor 24 to spin at its maximum spped. A washer 42 is inserted between the hub 37 of the rotor 24 and the mast 23 to reduce wear. Rotor blades 35, 36 are pitched at a slightly different angle from one another and have an airfoil section as illustrated in the end view of FIG. 3. Foil angle 43 is designed to allow a counterclockwise direction of rotation from the airflow the rotor catches when viewed from above from the center of the circle of flight. Thus the rotor 24 gets more lift from blade 35 than from blade 36. The angular relationship between blades may vary to suit various air foil designs, some of which may eliminate foil angle 43. Rotor blades 35, 36 are positioned such that the leading edge of blade 35, which provides greater lift than blade 36, is inward toward the operator. Lift side 35 is used to benefit control line 48, 49 tension during normal flight by tilting auto-giro slightly outward from the operator.

Propeller 29 is a left-handed propeller in the configuration illustrated in FIG. 4, rotating in a clockwise direction, to increase still further the tension on control lines 48, 49. The combined effects of the position of rudder 22, lift blade 35, left-handed propeller 29, position of looped eye 50 (later to be described), the position of stabilator 33 and the size and location of bellcrank lever 44 cause the model auto-giro 20 to lean slightly toward the outside of the circular flight path at all speeds and in all flight manoeuvres, thus maintaining tension on the control lines 48, 49 at all times.

The control line system comprises a bellcrank lever 44 pivotally mounted at its center to the bottom of fuselage 21 immediately below rotor mast 23 as close to the center of gravity as possible and held in position by a mounting screw 45 whose shank serves as its shaft. Connected to the two in-lines 46, 47 of the bellcrank lever 44 are two flexible lines 48, 49. A looped eye 50 on a short wire shaft 51 is fixably mounted to fuselage 21 extending from one side thereof from the approximate center of gravity. Lines 48, 49 pass through looped eye 50 to prevent them from becoming entangled in the propeller 29 and rotor 24. Eye 50 is positioned so that when lines 48, 49 pass through it, their normal angle 52 to the longitudinal axis of the fuselage is slightly obtuse, as shown in FIG. 2, to create more tension in lines 48, 49. Lines 48, 49 terminate at two ends of bar 53 which is held in the hand 54 of the operator. A rigid wire line 55 connects the bellcrank lever 44 at branch 56 to a downward projecting tab 57 on stabilator 33, which is pivotally connected to fuselage 21 at point 58, the raising or lowering of the stabilator being controlled by the pivoting of bellcrank lever 44. As illustrated in FIG. 1, stabilator 33 is located at the approximate center line of the air slip stream created by drive propeller 29. Rudder 22 is rigidly placed at fixed angle 27 to insure outward force away from the operator to maintain tension on control lines 48 and 49 when speed of auto-giro 20 is minimal. The length of lines 48, 49 becomes the radius of the circular flight path of auto-giro 20, and varying the length of said lines will vary that radius. By a pivoting action of a bar 53 when lines 48, 49 are taut, the operator is able to cause a bellcrank lever 44 to pivot, thereby pivoting the trailing edge of the stabilator edge 33 through arc 24 to control the pitch of the auto-giro 20.

The first configuration described above operates on captive control lines 48, 49 which are manipulated by an operator holding bar 53. This model is confined to a circular path whose radius is the length of lines 48, 49. The model is operated by placing it on the ground and, with the assistance of an operator's helper, starting the engine 28, which drives the propeller 29. With the engine operating, the helper releases the model auto-giro 20 which will start to roll along the ground. The flow of air now rushing past rotor blades 35, 36 causes rotor 24 to autogirate freely. As the flow of air past airfoils 35, 36 increases in velocity, the auto-giro 20 commences to lift off the ground, the lift being provided primarily by airfoils 35 and 36. By pivoting bar 53 the operator can pull line 46 while releasing tension on line 48. This action rotates bellcrank lever 44 such that rigid link 55 connected to tab 57 on stabilizer 33 is pushed backwards causing the trailing edge of stabilator 33 to be raised to a take-off position. After take-off the tension is equilized on the lines to permit the stabilator to return to a roughly horizontal position for level flight. In this configuration, the auto-giro can ascend, descend, loop, land and take off again. The auto-giro will glide and land safely if the fuel supply is exhausted or the engine fails. A third control line can be added to control the engine throttle for increase or decrease of speed. While this configuration is able to move up and down by utilization of a pivoting stabilator, it cannot hover.

An alternate configuration described in this paragraph will enable auto-giro 60 to hover. The modification required for hovering embraces a fixed horizontal stabilizer and a tiltable rotor as described hereafter. With reference to FIG. 5, the auto-giro 60 has a rudder 61 similar to rudder 22 of FIG. 1, but increased in size, and horizontal stabilizer 62 is rigidly attached thereto so that the slip stream of drive propeller 29 is approximately parallel to stabilizer 62. Rotor mast 63 contains pivoting linkage 64 connecting it to a rotor shaft 65 which is adapted to receive rotor 66 similar to rotor 24 of FIG. 1. Rotor 66 is held in position by a thrust bearing 67 and nut 68. An L-shaped rigid wire link 69 is inserted and secured in the lower portion of rotor shaft 65 and extends vertically downward to and through a hole 70 in branch 71 of bellcrank lever 72 where it is allowed to float freely. The pivoting action of control bar 53 causes bellcrank lever 72 to pivot branch 71 through an arc 73 forcing rigid link 69 to cause rotor shaft 65 to pivot through arc 74, thereby tilting rotor 66. This tilting action enables auto-giro 60 to hover as well as perform all other flight manoeuvres of the first configuration, though still confined to a circular flight path as defined by the length of control lines 48, 49.

Both configurations of the model auto-giro disclosed above may be modified to utilize remote radio controls. The third configuration, illustrated in FIG. 9, is essentially similar to the first configuration, illustrated in FIG. 1, except for the modifications necessary for radio control. The general construction of the third configuration including the pivoting stabilator and nontiltable rotor shaft as illustrated in FIGS. 1, 2 and 3 with the modifications shown in FIG. 9. All components related to captive line control, such as bellcrank lever 44, loop eye 50, loop eye shaft 51, control lines 48, 49, operator bar 53, as shown in the configuration of FIG. 1 are eliminated from the configuration of FIG. 9. As shown in FIG. 9, auto-giro 75 has a fuselage 76 which is modified to accept radio control components comprising a battery 77, a multi-channel receiver 78, a servo-motor 79 to operate the throttle (not shown) of engine 80, a servo-motor 81 to operate a pivoting rudder 82, and a servo-motor 83 to operate pivoting stabilator 84. All these control units are located in the fuselage 76 near or under rotor mast 85 to counterbalance the weight of engine 80. The auto-giro 75 is controlled by a multi-channel transmitter 86, shown in FIG. 11.

In this third configuration, auto-giro 75 has a pivoting rudder 82 constructed as a separate part and hinged at the upper rear of fuselage 76 by means of two inwardly projecting tips 87. The upper rear of fuselage 76 contains two recesses 88 to receive tips 87. Servo-motor 81 drives a shaft 89 which extends outward through the bottom of the fuselage and on which is mounted a rotating disk 90. Disk 90 is connected by a rigid wire link 91 to rudder 82 and inserted in slot 92 on rudder 82. Pivoting disk 90 over an arc of approximately 120° causes a rudder 82 to pivot over a corresponding arc. Servo motor 83 drives a shaft 93 which extends outward through the fuselage and on which is mounted a rotating disk 94. Disk 94 is connected by rigid wire link 95 to tab 96 which projects downward from the leading edge of stabilator 84 to pivot the stabilator 84 up or down through arc 97. An antenna 98 is attached to fuselage 76 for reception of radio signals from transmitter 86.

This third configuration illustrated in FIG. 9 and described in the preceding paragraph can perform all flight manoeuvres except hovering, but is not constrained to a circular flight path as was the first configuration.

The fourth configuration, illustrated in FIG. 10, is essentially similar to the second configuration, illustrated in FIG. 5 except for the modifications necessary for radio control in which respect it is similar to the third configuration illustrated in FIG. 9. The general construction of the fourth configuration, including the fixed horizontal stabilizer and the tiltable rotor shaft is illustrated in FIGS. 5, 6 and 7 with the modifications shown in FIG. 10. All components related to captive line control such as bellcrank lever 72, loop eye 50, loop eye shaft 51, lines 48, 49 and operator bar 53, as shown in the configuration of FIG. 5 are eliminated form the configuration of FIG. 10. As shown in FIG. 10, auto-giro 99 has a fuselage 100 which is modified to accept radio control components similar to the third configuration. The fourth configuration, however, has a fixed horizontal stabilizer 101 and does not require the stabilator controls shown in FIG. 9. This configuration has a tiltable rotor shaft 102 similar to that of the second configuration as illustrated in FIG. 5. A servo motor 102 drives a shaft 104 extending through the side of rotor mast 105 to which a rotating disk 106 is attached. Disk 106 is connected by a rigid wire link 107 to a tab 108 projecting rearwardly from rotor shaft 102 and attached thereto. Rotation of disk 106 causes link 107 to tilt shaft 102 through arc 109. This design has a rudder actuator similar to that of the third configuration illustrated in FIGS. 9 and 10. This configuration is able to perform all the flight manoeuvres of the third configuration and is also capable of hovering.

Further variations in the configurations described above and in their methods of control are possible. The gasoline powered engine could be mounted behind the rotor shaft and equipped with a pusher propeller. Additional auxilliary fuel tanks could be provided for extended flight. Throttle controls may be installed on the first two configurations. A model pilot and pilot seat may be installed with its location dependent on the location of the engine.

While only certain embodiments of this invention have been shown and described by way of illustration, many modifications within the true spirit and scope of this invention and within the following claims will occur to those skilled in the art.