Control apparatus and method for operating an aircraft

Claim 2

A control device for an aircraft having a rigid rotor with variable pitch blades capable of sustaining a steady offset rotor thrust vector comprising: first means for varying the pitch of the blades cyclically to control the lateral offset of the rotor thrust vector from the center of the rotor on the advancing blades of the rotor; second means for varying the pitch of the blades collectively to increase or decrease the magnitude of the rotor thrust vEctor; and third means coupling the second means to the first means for varying the cyclic pitch of the rotor in nondirect proportional relationship with the collective pitch of the rotor whereby a decrease in collective pitch is accompanied by a controlled increase in the amount of cyclic pitch.

Claim 3

The control device of claim 1 further including fourth means operatively associated with the second means for locking the second means and the third means at a predetermined collective pitch.

Claim 4

A control device for an aircraft having a pair of counterrotating thrust producing rotors with at least three variable pitch blades rigidly supported from a rotor hub for producing steady offset rotor lift vectors comprising: first means connected with the blades of the one rotor for cyclically varying the pitch to control the lateral offset of the lift vector on the advancing blades of the one rotor; second means connected with the blades of the other rotor for cyclically varying the pitch to control the lateral offset of the lift vector on the advancing blades of the other rotor; third means connected with the blades of each rotor for collectively varying the pitch of the blades of each rotor; and fourth means coupling the first, second and third means for varying the cyclic pitch of the two rotors to control the lateral offset of the lift vectors of the rotors on the advancing blades in response to the collective pitch variation of third means.

Claim 5

A control device for an aircraft having a pair of counterrotating thrust producing rotors with at least three variable pitch blades rigidly supported from a rotor hub for producing steady offset rotor lift vectors comprising: first means connected with the blades of the one rotor for cyclically varying the pitch to control the lateral offset of the lift vector on the advancing blades of the one rotor; second means connected with the blades of the other rotor for cyclically varying the pitch to control the lateral offset of the lift vector on the advancing blades of the other rotor; third means connected with the blades of each rotor for collectively varying the pitch of the blades of each rotor; and fourth means coupling the first, second and third means for varying the cyclic pitch of the two rotors to control the lateral offset of the lift vectors of the rotors on the advancing blades in response to the collective pitch variation of third means.

Claim 6

The device of claim 3 wherein the fourth means varies the cyclic pitch in increments proportional to the collective pitch variations.

Claim 7

The device of claim 4 wherein the fourth means varies the cyclic pitch in a nondirect proportional relationship with the collective pitch of the blades to control the offset of the lift vectors in opposite lateral directions.

Claim 8

Apparatus for controlling the thrust vectors in an aircraft rotor system having two counterrotating rotors, each rotor having at least three blades extending rigidly from a rotor hub comprising: first means for variably positioning the thrust vector of the one rotor over the advancing blades of the one rotor and along a first lateral radial of the aircraft rotor system; second means for variably positioning the thrust vector of the other rotor over the advancing blades of the other rotor and along a second lateral radial of the aircraft rotor system; third means connected to both rotors for varying the magnitude of the thrust vectors of both rotors in unison; and fourth means connecting the first and second means to the third means for operating the first and second means in response to the third means and thereby variably positioning the thrust vectors of the respective rotors along the radials as a function of the magnitude of the thrust vectors.

Claim 9

Apparatus for controlling the thrust vectors in an aircraft rotor system having two counterrotating rotors, each rotor having at least three blades extending rigidly from a rotor hub comprising: first means for variably positioning the thrust vector of the one rotor over the advancing blades of the one rotor and along a first lateral radial of the aircraft rotor system; second means for variably positioning the thrust vector of the other rotor over the advancing blades of the other rotor and along a second lateral radial of the aircraft rotor system; third means connected to both rotors for varying the magnitude of the thrust vectors of both rotors in unison; and fourth means connecting the first and second means to the third means for operating the first and second means in response to the third means and thereby variably positioning the thrust vectors of the respective rotors along the radials as a function of the magnitude of the thrust vectors.

Claim 10

Apparatus of claim 6 wherein: the first means include means for cyclically varying the lateral cyclic pitch of the blades of the one rotor; the second means include means for cyclically varying the lateral cyclic pitch of the blades of the other rotor; the third means include means for varying the collective pitch of both rotors in unison; and the fourth means couple the collective pitch means to the lateral cyclic means to vary the lateral cyclic pitch on both rotors in a nondirect proportional relationship with collective pitch.

Claim 11

Apparatus of claim 7 wherein the fourth means provide a nondirect proportional relationship in which the coupled lateral cyclic pitch increases from a zero value as collective pitch decreases from a value greater than zero.

Claim 12

In an aircraft, the combination including: two counterrotating rigid rotors positioned symmetrically with respect to the longitudinal aircraft axis to present advancing blade patterns on opposite lateral sides of the aircraft; first lateral cyclic means connected with the rotor blades for cyclically changing blade pitch of both rotors and establishing symmetrically positioned thrust vectOrs laterally offset from the rotor axes on the advancing blades of the respective rotors; collective means also connected with the rotor blades for collectively changing the blade pitch of both rotors to increase or decrease the combined thrusts of the rotors; and collective coupling means connecting the first lateral cyclic means to the collective means for rendering the symmetric lateral offset of the thrust vectors a function of the collective pitch.

Claim 13

In an aircraft, the combination including: two counterrotating rigid rotors positioned symmetrically with respect to the longitudinal aircraft axis to present advancing blade patterns on opposite lateral sides of the aircraft; first lateral cyclic means connected with the rotor blades for cyclically changing blade pitch of both rotors and establishing symmetrically positioned thrust vectOrs laterally offset from the rotor axes on the advancing blades of the respective rotors; collective means also connected with the rotor blades for collectively changing the blade pitch of both rotors to increase or decrease the combined thrusts of the rotors; and collective coupling means connecting the first lateral cyclic means to the collective means for rendering the symmetric lateral offset of the thrust vectors a function of the collective pitch.

Claim 14

The combination of claim 9 wherein the rotors are coaxially mounted.

Claim 15

The combination of claim 9 wherein the collective coupling means renders the lateral cyclic pitch a nondirect proportional function of the collective pitch.

Claim 16

The combination of claim 11 wherein the coupled lateral cyclic pitch is substantially zero at the value of collective pitch for hovering.

Claim 17

The combination of claim 9 further including second lateral cyclic means connected with the rotor blades for cyclically changing the blade pitch of both rotors and establishing thrust vectors positioned asymmetrically with respect to the rotor axes on the advancing or retreating blades of the rotors thereby generating rolling moments for aircraft control.

Claim 18

The combination of claim 9 further including: restraining means operatively associated with the collective means for holding the collective pitch of the rotors and consequently the coupling means at a preselected position; and propulsion means independent of the counterrotating rotors for regulating the forward speed of the aircraft.

Claim 23

The method of claim 16 further including the step of rendering the vector-restricting lateral cyclic pitch dependent upon the collective pitch of the rotors.

Claim 24

The method of claim 17 including the further step of differentially combining additional lateral cyclic pitch with the pitch of the rotor blades to generate aircraft rolling moments for aircraft control.

Claim 25

The method of claim 17 including the additional step of holding the collective pitch of the rotors constant above a preselected forward speed of the aircraft.

Claim 26

The method of claim 19 including the further step of superimposiNg longitudinal cyclic pitch on the pitch of the rotor blades to vary the angle of attack of the rotors and consequently lift generated by the rotors while the collective pitch of the rotors is held constant.