US3771923A

US3771923A - Autogyros, especially permitting the use of these devices as economical airground vehicles

Info

Publication number: US3771923A
Application number: US00198664A
Authority: US
Inventors: R Demontaigu; R Stock
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-11-13
Filing date: 1971-11-15
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13
Also published as: FR2116230A1; IT944912B; GB1350505A; FR2116230B1; CA942729A

Abstract

Improvements in the rotor system of autogyros permitting the easy folding back of the rotor blades and to ensure the coincidence of the blade axes in a single point. A smooth ball and socket joint housed in the head of a mast supporting the motor is traversed by a shaft about which there is pivoted a member in the form of a cardan fork carrying bearing centered on the axis of rotation and housed in the hub of the rotor, the articulation axes of oscillation of the rotor blades being aligned and mounted in such manner in the hub that they pass through the pivotal center of the unit, the centrifugal force of one of the blades being balanced by that of the other so that no reaction due to these forces is produced on the hub irrespective of the direction of inclination of the rotor.

Description

United States Patent 11 1 DeMontaigu et a1.

11] 3,771,923 1451 Nov. 13, 1973 AUTOGYROS, ESPECIALLY PERMITTING [76] Inventors: Rene Ce'sar Alexandre T assin DeMontaigu, Paris; Ren Stock, Marseille, both of France [22] Filed: Nov. 15, 1971 21 Appl. No.: 198,664

[30] Foreign Application Priority Data Nov. 13, 1970 France 7040547 [521 US. Cl. 416/143, 416/148 [51] Int. Cl. B64c 27/50 [58] Field of Search 416/142, 102, 143,

[56] References Cited UNITED STATES PATENTS 2,631,679 3/1953 Hiller et a1 416/102 X 3,080,002 3/1963 DuPont 416/102 3,087,690 4/1963 Doman et a1. 416/148 3,451,484 6/1969 Sawicki et al 416/148 X 2,105,682 1/1938 Bennett et a1.. 416/148 2,464,285 3/1949 Andrews 416/143 UX 2,815,820 12/1957 Papadakos 416/143 3,204,700 9/1965 Milligan 416/148 FOREIGN PATENTS OR APPLICATIONS 608,459 9/1948 Great Britain 416/148 419,780 4/1947 Italy 4l6/102 Primary Examiner-Everette A. Powell, Jr. Attorney-Karl W. Flocks [57] ABSTRACT Improvements in the rotor system of autogyros permitting the easy folding back of the rotor blades and to ensure the coincidence of the blade axes in a single point.

A smooth ball and socket joint housed in the head of a mast supporting the motor is traversed by a shaft about which there is pivoted a member in the form of a cardan fork carrying bearing centered on the axis of rotation and housed in the hub of the rotor, the articulation axes of oscillation of the rotor blades being aligned and mounted in such manner in the hub that they pass through the pivotal center of the unit, the centrifugal force of one of the blades being balanced by that of the other so that no reaction due to these forces is produced on the hub irrespective of the direction of inclination of the rotor.

6 Claims, 4 Drawing Figures PATENTEUNUY 13 I973 SHEET 3 OF 4 AUTOGYROS, ESPECIALLY PERMITTING THE USE OF THESE DEVICES AS ECONOMICAL AIRGROUND VESSELS Up to the present time, no success has been achieved in putting into operation a practical and economic aero-terrestrial vehicle. However, one of the elements essential to its production exists since the perfecting of the autogyro by Juan de la Cierva, the rotor of which lends itself to an easy and rapid transition from the road vehicle position to the flying position and vice-versa.

The present invention has for its object on the one hand to permit easy folding back on themselves of the rotor blades in order that they do not exceed the length of the vehicle and, on the other hand, to make arrangements at the head of the two-blade rotor which, while retaining the oscillation and drag articulations of the blades by which la Cierva reduced the fatigue in the blades, nevertheless make it possible to ensure the coincidence of the blade axes in a single point, irrespective of the inclination of the vertical plane to the axis of rotation of the rotor (which was not the case with the la Cierva rotor) eliminating opposing moments and vibrations in the flight controls.

The invention contemplates a folding rotor system of an autogyro which especially permits the use of this device as a practical, robust and economical air-ground vehicle. This rotor system is characterized in that a smooth ball and socket joint housed in the head of a supporting mast for the rotor is traversed by a shaft about which there can pivot a member in the form of a cardan fork carrying bearings centered on the axis of rotation and housed in the hub of the rotor, the axes of articulation of the oscillations of the blades being aligned and mounted in such manner in the hub that they pass through the pivotal center of the whole unit; the centrifugal forceof one of the blades being balanced by that of the other, no reaction due to these forces takes place on the hub, irrespective of the direction of its inclination.

Vertical supporting pivots rigidly fixed to the fuse Iage are housed in the folding back articulations of the rotor blades and absorb the torsion force generated on the basic sections of the blades during the folding operation.

Other characteristic features and advantages of the present invention will be brought out in the description which follows below, reference being made to the accompanying drawings, in which:

FIG. 1 is a view-in elevation of an aero-terrestrial vehicle according to the invention;

FIG. 2 is a view looking-on the top of the two-blade rotor, one of the blades of which is folded back;

FIG. 3 is a view looking from above and to a larger scale of the hub fitted with attachment stirrups for the blades;

FIG. 4 is a view in vertical cross-section of the rotor hub mounted on the supporting mast of the machine.

According to the invention, vertical supporting pivots 1 (see FIG. 1) rigidly fixed on the fuselage and engaging in sockets 2 of articulations 3 (see FIG. 2) permitting the folding back of the blades, absorb the torsion force generated on the basic sections 4 of the blades during the folding operation (see FIG. 2).

In addition, they ensure the support of the blades when folded back in the road vehicle position. To this end, the supporting pivots I of the blades can be fixed to the fuselage by arms 5 which may be retractable and form a triangulation. Two arms 5 support by their pivot 1 one of the folded-back blades at the front of the fuselage and the extremity of that folded towards therear by a cradle 5a rigidly fixed to these arms, and two other arms 5 support by the other pivot l the other blade folded-back to the rear of the fuselage and the extremity of that folded towards the front by another cradle 5a rigidly fixed to these other arms.

These arms pivot about axes 6 and can be retracted in the flying position. The vertical extremity of the pivots l is conical in order to facilitate the operation involved in engaging them inside the socket 2 of the articulations.

The end sections 7 of the blades may be maintained in the alignment of the basic sections 4 in the flying position by means of a pin system passing into holes 8 fonned in extensions 9 and 10 of these sections coupled together by the articulations 3, these holes 8 being placed opposite each other.

This arrangement, permitting the fuselage to absorb the torsion force acting at the base of a blade which can be folded on itself, when it is folded back without being retained, may be applied to all cases of utilization of rotating wings, especially to helicopters in which it is desired to restrict the space occupied on the ground. It is in particular possible to contemplate, in the case of a rotating wing system of large diameter, the supporting of each portion of the blade to be folded by a stay supported against the ground.

The rotor system of the machine according to the invention is arranged at the head of a mast ll fixed and rigidly secured to the machine. This head is pierced by an eye 11a serving as a housing for a smooth ball and socket joint 12 in which is mounted a shaft 13 carrying needle-bearings 14 about which oscillates a member 15 serving as a fork. On this fork are mounted, at the upper portion, a bearing 16 supporting an axial load directed upwards corresponding to the weight of the whole of the machine during flight, at the lower portion a bearing 17 in opposition to the bearing 16 carrying the rotor-blades unit when used as a road vehicle.

Two shafts 19 are partly housed in the hub 18 in the case of a mounting with links of a single piece or alternatively are formed integral with the hub 18 in the case of a mounting with links in several parts.

Externally to the hub, they constitute the two portions of the same articulation axis BB for each of the two blades of the rotor. Each blade is mounted as a hinge on this pivotal axis and comprises at its base a stirrup P having two links 20 and one link 21. The link 21 of one stirrup is arranged between the two links 20 of the other (see- FIGS. 3 and 4).

A split conical sleeve ensures the absence of play and tightening is effected by means of rings 22 of needlebearings, with the aid ofa nut 23 locked by any conventional locking means.

A positioning stud 12a, arranged radially, prevents the ball and socket jointfrom moving about the axis of rotation of the hub under the effect of the frictional forces of the bearings.

The whole unit is operated angularly by a member 24 on which are mounted a bearing 25 and an operating lever 26. The base of the part 24 oscillates about the center of the ball and socket joint driving in its movements a floating member 27 which slides on an antitorque cradle 28 rigidly fixed to the mast.

The launching of the rotor is effected by a pinion 29 sliding inside a casing 30 and coming into engagement with a toothed wheel 31 of the hub 18. The driving torque is transmitted by a shaft 32 and ajoint 33. Braking is effected by means of brake-shoes 34 in frictional contact with the interior of the ring 31 forming a brakedrum.

The rotor hub device for a rotating wing system according to the invention makes possible, in spite of the presence of an individual oscillation articulation for each blade, the coincidence of the axes of articulation of the hub and the blades at a single point 0, irrespective of the direction of the axis of rotation of the rotor and the angle of lift of the blades, so that the resultant of all the static and dynamic forces, especially those due to angular acceleration or centrifugal forces, passes through the center of the rotor, thus avoiding any moment with respect to this center which could be a generator of vibration and instability during rotation and during evolutions in course of flight.

The invention offers the same advantages as with rigid blades fixed in respect of oscillations. The fixed portion is only required to withstand the forces corresponding to the driving torque for launching or those due to braking. During auto-rotation, the forces are extremely small as compared with the centrifugal force.

The control of inclination of the blades is effected in such manner as to coexist, in the best aerodynamic position, with the launching device of the rotor, whether it is mechanical or hydraulic with one or with several driving pinions.

It will of course be understood that the present invention has only been described and illustrated by way of a preferred example, and equivalents may be employed in its constituent elements without thereby departing from the scope of the said invention as defined in the appended claims.

We claim:

1. Rotor system of the autogyro type, especially permitting the use of a machine as an air-groud vehicle which is practical, robust and economical, said system comprising in combination a mast supporting a rotor member and including a head portion formed with an eyelet in which is disposed a smooth ball and socket joint, said ball and socket joint being traversed by a shaft, a cardan fork member supported on said shaft in pivotal relationship thereabout, said cardan fork carry ing bearings disposed in concentric relationship with the axis of rotation of said rotor member, said bearings also being housed within a hub portion of said rotor member whereby rotor blades may be mounted on said hub portion with the articulation axes of oscillation thereof aligned in such manner that they pass through the pivotal center of said system so that centrifugal force of one blade will balance that of the other with the result that no reaction due to these forces would be produced on the hub portion irrespective of the direction of inclination of the rotor member.

2. Rotor system in accordance with claim 1, charac terized in that two shafts partly housed in the hub portion constitute externally of the said hub portion the two portions of a single axis of articulation of oscillation for each of the two blades of the rotor member, each blade being mounted as a hinge on the said articulation axis and comprising at its base a stirrup with links complementary to the links of the stirrup of the other blade.

3. Rotor system in accordance with claim 1, characterized in that an inclination control acts on a cradle which can move in the longitudinal and transverse di' rection around the center of the rotor member, a floating member permitting these 2 of freedom, while preventing angular displacement about the axis of rotation and thus forming an anti-torque to the moment of the mechanical launching and braking, this sliding member moving over a base fixed on the mast rigidly attached to the machine.

4. Rotor system in accordance with claim 3, characterized in that the inclination control of the said rotor is effected in such manner as to coexist, in the best aerodynamic position, with the launching device of the rotor, whether this is mechanical or hydraulic, with one only or several driving pinions.

5. Rotor system in accordance with claim 1, characterized in that vertical pivot supports are fixed in the articulations for folding back the blades and absorb the torsion force generated on the base sections of the blades during the folding operation.

6. Rotor system in accordance with claim 5, characterized in that the pivot supports are fixed to the fuselage of the machine by arms forming a triangulation and being retractable if so desired. a: a: a:

Claims

1. Rotor system of the autogyro type, especially permitting the use of a machine as an air-groud vehicle which is practical, robust and economical, said system comprising in combination a mast supporting a rotor member and including a head portion formed with an eyelet in which is disposed a smooth ball and socket joint, said ball and socket joint being traversed by a shaft, a cardan fork member supported on said shaft in pivotal relationship thereabout, said cardan fork carrying bearings disposed in concentric relationship with the axis of rotation of said rotor member, said bearings also being housed within a hub portion of said rotor member whereby rotor blades may be mounted on said hub portion with the articulation axes of oscillation thereof aligned in such manner that they pass through the pivotal center of said system so that centrifugal force of one blade will balance that of the other with the result that no reaction due to these forces would be produced on the hub portion irrespective of the direction of inclination of the rotor member.

2. Rotor system in accordance with claim 1, characterized in that two shafts partly housed in the hub portion constitute externally of the said hub portion the two portions of a single axis of articulation of oscillation for each of the two blades of the rotor member, each blade being mounted as a hinge on the said articulation axis and comprising at its base a stirrup with links complementary to the links of the stirrup of the other blade.

3. Rotor system in accordance with claim 1, characterized in that an inclination control acts on a cradle which can move in the longitudinal and transverse direction around the center of the rotor member, a floating memBer permitting these 2* of freedom, while preventing angular displacement about the axis of rotation and thus forming an anti-torque to the moment of the mechanical launching and braking, this sliding member moving over a base fixed on the mast rigidly attached to the machine.

6. Rotor system in accordance with claim 5, characterized in that the pivot supports are fixed to the fuselage of the machine by arms forming a triangulation and being retractable if so desired.