Antitorque and propulsion rotor

Claim 2

In a helicopter, a tail rotor for supplying antitorque and propulsive thrust forces, said rotor comprising a hub and a plurality of blades attached thereto and inclined at a selected cone angle with respect to the axis of rotation of said rotor, means for varying the cone angle at which said blades are inclined with respect to the axis of rotation, drive means operatively associated with said rotor for driving same, and pitch means in operative association with said rotor and capable of varying the collective and cyclic pitch of said blades to enable said rotor to assume various operative modes including a propulsive mode, an antitorque mode, a lifting mode, and modes which are combinations thereof.

Claim 3

The rotor of claim 1 wherein said cone angle is between about 30* and 70* with respect to the axis of rotation.

Claim 4

The rotor of claim 1 wherein reinforcing bracing means are incorporated in said blades in order to oppose centrifugal flap bending moments in the blades which may occur during rotation of said blades.

Claim 5

A hingeless tail rotor for use in a vertical lift aircraft comprising a hub and a plurality of blades connected to said hub, a drive means connecting said hub to an engine of said aircraft, pitch means for inducing collective and cyclic pitch on said rotor blades, said blades being mounted on said hub in a manner wherein said blades form a cone angle of between 30* and 70* with respect to the rotor axis of rotation, means for varying said cone angle within said range of 30* to 70* with respect to the rotor axis of rotation, each blade being twisted along its longitudinal axis to establish a relatively uniform angle of attack of the blade and said rotor, when having the proper pitch induced thereon, being capable of operating in one of a plurality of modes including an antitorque mode, a propulsive mode, a lifting mode, a combined antitorque and propulsive mode, and a combined lifting and antitorque mode.

Claim 6

A hingeless tail rotor for use in a vertical lift aircraft comprising a hub and a plurality of blades connected to said hub, a drive means connecting said hub to an engine of said aircraft, pitch means for inducing collective and cyclic pitch on said rotor blades, said blades being mounted on said hub in a manner wherein said blades form a cone angle of between 30* and 70* with respect to the rotor axis of rotation, means for varying said cone angle within said range of 30* to 70* with respect to the rotor axis of rotation, each blade being twisted along its longitudinal axis to establish a relatively uniform angle of attack of the blade and said rotor, when having the proper pitch induced thereon, being capable of operating in one of a plurality of modes including an antitorque mode, a propulsive mode, a lifting mode, a combined antitorque and propulsive mode, and a combined lifting and antitorque mode.

Claim 7

A tail rotor mountable to the tail section of a single main rotor helicopter having an engine and a drive shaft extending from said engine to said tail section, said rotor comprising a hub and a plurality of blades attached to said hub and adapted to rotate therewith, said hub being adapted for operative connection to said drive shaft and being driven thereby, each of said blades forming a cOne angle with respect to the rotor axis of rotation, said cone angle being in the range from about 30* to 70*, means for varying said cone angle within said range of 30* to 70* with respect to the rotor axis of rotation, pitch means for inducing collective and cyclic pitch on said blades to enable said rotor to operate in any one of a variety of modes including an antitorque mode to counteract the torque of the main rotor exerted on said helicopter, a propulsive mode for supplying forward thrust to said helicopter, a lifting mode, and modes which are combinations thereof.

Claim 8

A tail rotor mountable to the tail section of a single main rotor helicopter having an engine and a drive shaft extending from said engine to said tail section, said rotor comprising a hub and a plurality of blades attached to said hub and adapted to rotate therewith, said hub being adapted for operative connection to said drive shaft and being driven thereby, each of said blades forming a cOne angle with respect to the rotor axis of rotation, said cone angle being in the range from about 30* to 70*, means for varying said cone angle within said range of 30* to 70* with respect to the rotor axis of rotation, pitch means for inducing collective and cyclic pitch on said blades to enable said rotor to operate in any one of a variety of modes including an antitorque mode to counteract the torque of the main rotor exerted on said helicopter, a propulsive mode for supplying forward thrust to said helicopter, a lifting mode, and modes which are combinations thereof.

Claim 9

The rotor of claim 1, wherein said means for varying said cone angle comprises a shaft capable of extending and retracting out of and into said tail section, a plurality of rods universally coupled to said shaft at one end, each rod being universally coupled to a blade at its other end whereby extension and retraction of said shaft causes said blades to be inclined at different angles with respect to said axis of rotation.

Claim 10

The rotor of claim 5 wherein reinforcing bracing means are incorporated in said blades in order to oppose centrifugal flap bending moments which may occur in said blades during rotation thereof.

Claim 11

The rotor of claim 5 wherein said blades are mounted to said hub in a hingeless fashion and said cone angle is selected from the range of about 45* to 60*.