MULTIPLE HELICOPTER LIFT SYSTEM

• US 3,656,723 A
• Filed: 12/16/1969
• Issued: 04/18/1972
• Est. Priority Date: 12/16/1969
• Status: Expired due to Term

• Current Assignee: Donald N. Meyers, Frank N. Piasecki
• Original Assignee: Donald N. Meyers, Frank N. Piasecki
• Inventors: Piasecki, Frank N., Meyers, Donald N.
• Primary Examiner(s): Buchler, Milton
• Assistant Examiner(s): Rutledge, Carl A.
• Application Number:
  US04/885,400
• Time in Patent Office: 854 Days
• Field of Search: 244/2,3,17,23,75,83,84,92,137
• US Class Current: 244/2
• CPC Class Codes: B64C 27/12 Rotor drives
• CPC Class Codes: B64C 27/14 Direct drive between power plant and rotor hub
• CPC Class Codes: B64C 37/02 Flying units formed by separate aircraft towing B64D3/00; aircraft transported by aircraft B64D5/00; air-refuelling B64D39/00
• CPC Class Codes: B64D 1/22 Taking-up articles from earth's surface

Abstract

A multiple helicopter lift system of two or more helicopters of the conventional type normally operating independently that are rigidly connected together in a spaced relationship by structural beam members to form an integral unit with the rotor drive systems of the attached helicopters interconnected so that the engines of each of the interconnected helicopters rotate at the same speed, as do the rotors. If desired the flight controls of all helicopters in the system are interconnected so that the rotational path and pitch of the rotors of all helicopters in the system are controlled from a single master pilot'"'"''"'"'s station in a manner to establish the necessary forces and moments required to effectively control the movement of the entire system of connected helicopters.

Claims

1. A multiple helicopter lift system comprising a plurality of helicopters, the flight control system of each helicopter including a collective pitch control operatively connected to actuators controlling the pitch of the blades of the main rotor system and attitude controls operatively connected to actuators controlling the pitch of each of the rotors of the helicopter for establishing the desired attitude of the helicopter, means attachable to the structure of each said helicopter for rigidly interconnecting said helicopters and securing them together in a fixed, spaced-apart relationship to form an integral unit, means interconnecting the rotor drive systems of all said helicopters, whereby the engines and rotors, respectively, of all helicopters are interconnected for operation at their same respective speeds, collective pitch control transducer means connected to the collective pitch control of one of said helicopters and to the collective pitch actuators of each of the other of said helicopters for establishing equivalent control movement in the collective pitch actuators of said other helicopters as is established in the collective pitch actuators of said one helicopter upon movement of the collective pitch control of said one helicopter, attitude control transducer means connected to each attitude control of said one helicopter and to selected rotor pitch control actuators of said helicopters for controlling said selected actuators in establishing a pitch of the rotors of all connected helicopters that produces an attitude of said integral unit similar to the attitude that would be produced in said one helicopter upon similarly positioning its attitude controls when operating independently in a normal configuration, said one helicopter attitude controls including a cyclic pitch control for controlling roll and pitch and the attitude control transducer means of said one helicopter cyclic pitch control being operatively connected to the collective pitch actuators of each of at least two connected helicopters located on opposite sides of a mid-point between the most widely spaced of said connected helicopters, said cyclic pitch attitude control transducer means and connections being arranged such that movement of said one helicopter cyclic pitch control in a given direction causes control movement in opposite directions of the respective collective pitch actuators of each of said two oppositely located helicopters, thereby increasing the pitch of the blades in the main rotor system of a helicopter on one side of said mid-point and decreasing the pitch of the blades in the main rotor system of a helicopter on the other side of said mid-point to establish a moment about a horizontal attitude control axis of said integral unit.

2. The lift system described in claim 1 wherein said one helicopter conventional attitude controls additionally include a rudder control for controlling yaw and the attitude control transducer means of said one helicopter rudder control is operatively connected to selected cyclic pitch actuators of said two oppositely located helicopters, said rudder attitude control transducer means and connections being arranged such that movement of said one helicopter rudder control in a given direction causes said selected cyclic pitch actuators of each of said two oppositely located helicopters to move oppositely in a direction that establishes a moment about the yaw axis of said integral unit.

3. The lift system described in claim 2 wherein said attitude control transducer means establishes in the respective attitude control actuators of each said other helicopter the equivalent control movement as is established in the corresponding attitude control actuators of said one helicopter by movement of said one helicopter attitude controls.

4. The lift system described in claim 3 additionally comprising means interconnecting the RPM controls of all said helicopters for causing the engine control of each said other helicopter to follow the engine controls of said one helicopter and means connected to the engines and engine control units for establishing the same torque output in all engines of said helicopters.

5. The lift system described in claim 1 wherein said helicopters are connected by said interconnecting means in a side-by-side arrangement with said one helicopter cyclic pitch control including a lateral and a longitudinal phase for controlling roll and pitch, respectively, and the attitude control transducer means connected to the lateral phase of said one helicopter cyclic pitch control has operative connections to the collective pitch control actuators of said two oppositely located helicopters, whereby lateral movement of said one helicopter cyclic pitch control establishes an increase in collective pitch of the main rotor blades of one of said two oppositely located helicopters and a decrease in collective pitch of the main rotor blades of the other of said oppositely located helicopters.

6. The lift system described in claim 5 wherein the attitude control transducer means connected to the longitudinal phase of said one helicopter cyclic pitch control has operative connections to the longitudinal pitch actuators of the rotor of each said other helicopter and establishes the same rotational path and pitch in the blades of the rotors of each said other helicopter as is established in said one helicopter upon longitudinal motion of said one helicopter cyclic pitch control, whereby longitudinal movement of said one helicopter cyclic pitch control establishes in each helicopter the normal pitch control forces present in normal independent flight of that helicopter.

7. The lift system described in claim 6 additionally comprising means interconnecting the RPM controls of all said helicopters for causing the engine control of each said other helicopter to follow the engine controls of said one helicopter and means connected to the engines and engine control units for establishing the same torque output in all engines of said helicopters.

8. The lift system described in claim 7 wherein said one helicopter conventional attitude controls additionally include a rudder control for controlling yaw and the attitude control transducer means of said one helicopter rudder control has operative connections to the longitudinal cyclic pitch control and actuators of said two oppositely located helicopters, said rudder attitude control transducer means and connections being arranged such that movement of said one helicopter Rudder control in a given direction causes said longitudinal cyclic pitch actuators of each of said two oppositely located helicopters to move oppositely, whereby aft longitudinal cyclic forces are established in the main rotor of one of said two oppositely located helicopters and forward longitudinal cyclic forces are established in the main rotor of the other of said oppositely located helicopters.

9. The lift system described in claim 8 wherein said attitude control transducer means establishes in the respective attitude control actuator of each said other helicopter the equivalent control movement as is established in the corresponding attitude control actuators of said one helicopter by movement of said one helicopter attitude controls.

10. The lift system described in claim 5 wherein said helicopter interconnecting means includes horizontally extending structural members connecting between adjacent helicopters, said structural members being streamlined in shape and being positioned at such an angle as to establish a positive angle of attack to the airflow during forward motion of said integral unit at cruise speed.

11. The lift system defined in claim 1 wherein said conventional one helicopter attitude control includes a yaw control, the attitude control transducer means of said one helicopter yaw control is operatively connected to the pitch actuator of a tail rotor such that movement of said one helicopter yaw control causes the pitch actuator of said tail rotor to change pitch establishing a moment about the yaw axis of said integral unit.

12. A multiple helicopter lift system comprising at least two independently operable helicopters of the conventional type, the conventional flight control system of each helicopter including a collective pitch control operatively connected to actuators controlling the pitch of the blades of the main rotor system and a cyclic pitch control and rudder control each operatively connected to actuators controlling the rotational path and pitch of each of the rotors of the helicopter for establishing the desired pitch, roll and yaw attitude of the helicopter when operating in independent flight, at least one beam structure having connections at each end adapted for being connected to the fuselage structure of one of said helicopters, attaching means for rigidly connecting said connection at each end of said beam structure to different helicopters for interconnecting said helicopters together through said beam structure in a side-by-side, spaced-apart arrangement, said beam structure having a span such that the rotating rotor blades of adjacent helicopters will not come into contact, drive shafts supported on said beam structure and connected to the rotor drive system of each helicopter connected to said beam structure, whereby the engines and rotors, respectively, of all helicopters are interconnected for operation at their same respective speeds, means interconnecting the RPM controls of all said helicopters for causing the engine control of each said other helicopter to follow the engine control of said one helicopter, transducer means connected to the collective pitch control of one of said connected helicopters and to the collective pitch controls of each of the other of said connected helicopters for causing the collective pitch controls of said other helicopters to follow the movement of the collective pitch control of said one helicopter, an integrating means connected into the collective pitch control system between the collective pitch control and the actuators controlling the collective pitch of the rotor blades of each of at least two helicopters located on opposite sides of a midpoint between the most widely spaced of the connected helicopters for superimposing in said collective pitch control system of each said oppositely located helicopters an input additional to that established by the collective pitch controls of each of said oppositely located helicopters, transducer means Connected to the lateral phase of the cyclic pitch control of said one helicopter and to the lateral phase of the cyclic pitch control of each of said other helicopters for causing the cyclic pitch controls of said other helicopters to follow any lateral actuation of the cyclic pitch control of said one helicopter, said transducer means connected to the lateral phase of the cyclic pitch control of said one helicopter additionally connecting to each said collective pitch integrating means in said two oppositely located helicopters for feeding said additional input to each said integrating means upon the cyclic pitch control of said one helicopter being laterally actuated, said lateral cyclic pitch control transducer means and associated integrating means in said oppositely located helicopters being arranged such that lateral actuation of said cyclic pitch control of said one helicopter increases the collective pitch of one of said two oppositely located helicopters and decreases the collective pitch of the other of said oppositely located helicopters, transducer means connected to the longitudinal phase of the cyclic pitch control of said one helicopter and to the longitudinal phase of the cyclic pitch control of each of said other connected helicopters for causing the cyclic pitch controls of said other helicopters to follow any longitudinal actuation of the cyclic pitch control of said helicopter, and transducer means connected to the rudder control of said one helicopter and to the rudder controls of each of said other connected helicopters for causing the rudder controls of said other helicopters to follow the movement of the rudder control of said one helicopter.

13. The multiple helicopter lift system described in claim 16 wherein an integrating means is connected into the cyclic pitch control system between the cyclic pitch control and the cyclic pitch actuators controlling the cyclic pitch of the rotor blades of each of said two oppositely located helicopters for superimposing in said cyclic control system of each said oppositely located helicopters an input additional to that established by the cyclic pitch control of each of said oppositely located helicopters, and said transducer means connected to the rudder control of said one helicopter additionally connects to each said cyclic pitch integrating means of said two oppositely located helicopters for feeding said additional input to each said cyclic pitch integrating means upon the rudder control of said one helicopter being actuated, said rudder control transducer means and associated integrating means in said oppositely located helicopters being arranged such that actuation of said rudder control of said one helicopter establishes a forward longitudinal cyclic pitch component in one of said two oppositely located helicopters and a rearward longitudinal cyclic pitch component in the other of said oppositely located helicopters.

14. A method of providing a load transporting capacity greater than the transporting capacity of a single, conventional helicopter operating independently comprising the steps of rigidly connected together in a fixed, spaced-apart relationship a plurality of helicopter units each having a flight control system that includes a rotor collective pitch control system operable through a collective pitch control means and an attitude control system operable through an attitude control means that includes a cyclic pitch control means, thereby establishing a rigidly connected assembly of helicopter units, applying the load to said assembly of helicopter units, operating the rotor drive systems of said connected helicopter units as a single system at the same RPM by interconnecting the rotor drive systems of all said connected helicopter units, controlling the flight control system of each said helicopter unit of the assembly by operating the collective pitch control systems of all said helicopter units through the collective pitch control means of One of said connected helicopter units, by operating the attitude control systems of all helicopter units through the attitude control means of said one helicopter unit to include operating the pitch control means of said one helicopter unit, and by causing the collective pitch of the rotor system of one of at least two of the connected helicopter units located on opposite sides of a midpoint between the most widely spaced of said units to increase and the collective pitch of the rotor system of the other of said oppositely located helicopters to decrease upon actuation of the cyclic pitch control of said one helicopter unit in controlling attitude along the direction of alignment of said oppositely located helicopter units.

15. A method of aerial towing comprising the steps of connecting the towing load to an assembly of more than one helicopter units which are rigidly connected together in a fixed, spaced-apart relationship, each helicopter unit having a collective pitch control system operable through a collective pitch control means and an attitude control system operable through an attitude control means that includes a cyclic pitch control means, causing the rotors of each of said helicopter units to rotate in synchronism at the same speed by interconnecting the rotor drive systems of all said helicopter units and controlling the flight path of said assembly from the pilot'"'"''"'"'s station of one of said helicopter units by operating the collective pitch control system of all said helicopter units from the collective pitch control means of said one helicopter unit, by operating the attitude control system of all said helicopter units from the attitude control means of said one helicopter unit and by causing the collective pitch of the rotor system of one of at least two of the connected helicopter units located on opposite sides of a midpoint between the most widely spaced of said helicopter units to increase and the collective pitch of the rotor system of the other of said oppositely located helicopter units to decrease upon actuation of the cyclic pitch control of said one helicopter unit in controlling attitude along the direction of alignment of said oppositely located helicopter units.

16. Aerial lift apparatus comprising in combination, a plurality of individual helicopter units each having a flight control system and rotor drive system, means rigidly interconnecting said helicopter units in fixed, spaced-apart relationship to form an integral assembly of rigidly interconnected individual units, means interconnecting the rotor drive systems of each of said units for operation of all said drive systems at the same synchronous speed, means operative between the flight control systems of all said units whereby all said flight control systems are controlled conjointly and stably by operation of any one of said flight control systems, said helicopter interconnecting means comprising a beam structure having connections at each end adapted for connecting to the structure of one of said helicopter units and attaching means for rigidly connecting said connection at each end of said beam structure to a different helicopter, said beam structure including horizontally extending structural members having a streamline shape and positioned such that the chord of said streamline shape is positioned so as to establish a predetermined angle to the airflow during the forward flight motion of said assembly, and at least some of said attaching means being adapted for adjusting the direction of the chord of said streamline structure members.

17. Aerial lift apparatus comprising in combination, a plurality of individual helicopter units each having a flight control system and rotor drive system, means rigidly interconnecting said helicopter units in fixed, spaced-apart relationship to form an integral assembly of rigidly interconnected individual units, means interconnecting the rotor drive systems of each of said uniTs for operation of all said drive systems at the same synchronous speed, means operative between the flight control systems of all said units whereby all said flight control systems are controlled conjointly and stably by operation of any one of said flight control systems, said helicopter interconnecting means comprising a beam structure having connections at each end adapted for connecting to the structure of one of said helicopter units and attaching means for rigidly connecting said connection at each end of said beam structure to a different helicopter, said beam structure including horizontally extending structural members having a streamline shape and positioned such that the chord of said streamline shape is positioned so as to establish a predetermined angle to the airflow during the forward flight motion of said assembly, and at least some of said streamline structural members being divided into at least two segments and include means for changing the relative alignment of said two segments.

18. In a multiple helicopter unit comprising a plurality of separate conventional helicopters each normally capable of independent, controlled flight and interconnected by structural members to form a plural helicopter assembly, the improvement of rigid connecting means attaching said structural members to each said helicopter for rigidly connecting said helicopters together in a fixed relationship to one another, means connected to the rotor drive systems of all said helicopters for causing the main lift rotors of all said helicopters to rotate at the same velocity, and means for connecting the flight control system of all said helicopters together for actuation by the pilot'"'"''"'"'s flight controls of one of said helicopters, the conventional flight control system of each said helicopter including a rotor collective pitch control system operable by the pilot'"'"''"'"'s collective pitch control, a rotor cyclic pitch control system operable by the pilot'"'"''"'"'s cyclic pitch control and a yaw control system operable by the pilot'"'"''"'"'s rudder control, and said flight system connecting means including means connecting to the pilot'"'"''"'"'s collective pitch control of one of said helicopters and the collective pitch control systems of all other of said helicopters for operating the collective pitch control systems of all said helicopters by actuating the collective pitch control of said one helicopter, means connecting to the pilot'"'"''"'"'s cyclic pitch control of said one helicopter and the cyclic pitch control systems of each of the other of said helicopters for operating the cyclic pitch control systems of all said helicopters by actuating the cyclic pitch control, of said one helicopter, means connecting to the pilot'"'"''"'"'s rudder control of said one helicopter and the yaw control systems of each said other helicopter for operating the yaw control systems of all said helicopters by actuating the rudder control of said one helicopter, and means connecting to the cyclic pitch control of said one helicopter and the collective pitch control systems of each of at least two connected helicopters located on opposite sides of a mid-point between the most widely spaced of said connected helicopters for causing the collective pitch of the rotor system of one of said oppositely located helicopters to increase and the collective pitch of the rotor system of the other of said oppositely located helicopters to decrease upon actuation of the cyclic pitch control of said one helicopter in controlling an attitude direction.

19. An aerial lifting system comprising, a plurality of separate aircraft vertical lifting units each having a powered rotor lifting system and a flight control system having a collective pitch control system actuated by a collective pitch control and an attitude control system actuated by at least one attitude control, means for rigidly connecting said units together in a rigidly fixed, spaced-apart relationship, means interconnecting the flight control systems of all said units for aCtuating the collective pitch and the attitude control systems of all units by actuating the collective pitch and attitude controls of one of said units and means operable upon actuation of an attitude control of said one unit for causing a differential actuation of the collective pitch control systems of two units oppositely located with respect to said connecting means.

20. The combination of claim 19 additionally comprising means mechanically interconnecting the lifting rotor drives of all said connected units to cause the lifting rotor of all connected units to rotate at the same speed.

21. The combination of claim 20 wherein said connecting means connects said units in tandem and said differential collective pitch actuation means is operable to establish a differential collective pitch in the rotors of said oppositely connected units upon actuation of said one unit cyclic pitch control in the pitch phase.

22. The combination of claim 20 wherein said connecting means connects said units in juxtaposition and said differential control pitch actuation means is operable to establish a differential pitch in the rotors of said oppositely connected units upon actuation of said one unit pitch control in the roll phase.