Abstract:
A compact electromechanical decoupler device is operatively connected between a manual control device of an aircraft and an electromechanical actuator that controls the flight modes of the aircraft. The electromechanical decoupler device is operable to decouple the operative connection between the manual control device and the electromechanical actuator with the absence of power supplied to the electromechanical decoupler device. The electromechanical decoupler device can recouple the operative connection between the manual control device and the electromechanical actuator on resupply of power to the electromechanical decoupler device and on manually achieving proper rotational alignment or indexing between the mechanical control device and the electromechanical actuator.

Description:
FIELD 
       [0001]    This disclosure pertains to a compact electromechanical device that is operatively connected between a manual control device of an aircraft and an actuator that controls the flight modes of the aircraft. The electromechanical device is operable to decouple the operative connection between the manual control device and the actuator with the absence of power supplied to the electromechanical device. The electromechanical device can recouple the operative connection between the manual control device and the actuator on resupply of power to the electromechanical device and on manually achieving proper rotational alignment or indexing between the manual control device and the actuator. 
       BACKGROUND 
       [0002]    A control system of an aircraft includes manual controls such as manually manipulated control sticks and foot pedals. The manual manipulation of the control sticks and the foot pedals by a pilot controls the flight of the aircraft. 
         [0003]    In some aircraft, the manual manipulation of the control sticks and foot pedals is assisted by a series of actuators. The actuators are operatively connected between the control sticks and foot pedals of the aircraft and the flight control surfaces of the aircraft, such as rotor blades, ailerons, trim tabs, etc. The actuators operate the flight control surfaces of the aircraft in response to manual manipulation of the control sticks and the foot pedals. Backdriving the actuator is necessary when the actuator is not operating. 
         [0004]    At times during flight, when the actuator is not operating, a particular maneuver of the aircraft will cause inertia forces from the actuators to the control stick and foot pedals. At times, the inertia forces translated back to the control sticks and food pedals are too great for the pilot to backdrive the actuator and could potentially lose control of the aircraft and injure the pilot. 
       SUMMARY 
       [0005]    The electromechanical decoupler of this disclosure is operable to separate a pilot of an aircraft from excessive inertia forces translated back from the actuator to the manual controls of the aircraft. The electromechanical decoupler allows the pilot to maintain control of mechanical flight controls of the aircraft when an actuator of the flight controls fails, or when the actuator is in a passive mode, resulting in higher than acceptable flight control forces being translated back to the pilot. 
         [0006]    The electromechanical decoupler includes a compact housing. The housing has a cylindrical outer wall. The cylindrical outer wall has a center axis that defines mutually perpendicular axial and radial directions relative to the housing. 
         [0007]    A plurality of housing projections are provided on an interior surface of the outer wall. The housing projections extend radially inwardly from the interior surface of the housing wall. The projections are configured as spur gear teeth that form a ring gear on the interior surface of the outer wall. 
         [0008]    The housing also includes a base plate that is connected to one side of the outer wall. The base plate has a center hole that extends through the base plate. The center hole is coaxial with the housing center axis. 
         [0009]    The housing also includes an end plate that is connected to the opposite side of the outer wall from the base plate. The end plate also has a center hole through the end plate. The center hole of the end plate is coaxial with the center axis. Additionally, the center hole through the end plate is aligned with the center hole through the base plate and has the same diameter dimension as the center hole through the base plate. 
         [0010]    A base plate bearing assembly is mounted in the center hole of the base plate and an end plate bearing assembly is mounted in the center hole of the end plate. 
         [0011]    Three alignment pins are connected to the end plate and extend axially into the interior volume of the housing. The alignment pins are parallel and are spatially, circumferentially arranged around the center axis. 
         [0012]    A shaft extends through the interior volume of the housing. The shaft is coaxial with the center axis. The shaft is mounted in the base plate bearing assembly and the end plate bearing assembly for rotation of the shaft in the housing. The shaft is secured against axial movement in the housing. 
         [0013]    A plurality of narrow, elongate guides are positioned on the shaft. The guides are spatially, circumferentially arrange around the shaft. The guides have straight axial lengths that extend along a portion of the shaft length. Additionally, each of the guides has a height dimension that extends radially outward from the shaft. 
         [0014]    A decoupler plate is mounted on the shaft. The decoupler plate has a circular configuration. A plurality of plate projections extend radially outward from an outer edge of the decoupler plate. The plate projections are complementary to the housing projections. The decoupler plate has a center hole with a plurality of axial grooves formed in the center hole. The grooves are spatially, circumferentially arranged around the center hole. The plurality of guides on the shaft engage in the plurality of grooves in the center hole of the decoupler plate securing the decoupler plate against rotation relative to the shaft, but enabling axial movement of the decoupler plate over the shaft. The decoupler plate is axially moveable on the shaft in opposite first and second axial directions between a first position of the decoupler plate relative to the shaft and a second position of the decoupler plate relative to the shaft. In the first position of the decoupler plate relative to the shaft, the plate projections of the decoupler plate are meshed with the housing projections of the housing, thereby connecting the decoupler plate to the housing, and connecting the shaft to the housing. In the second position of the decoupler plate relative to the housing, the plate projections on the decoupler plate are moved out of mesh with the housing projections of the housing, thereby disconnecting the plate from the housing and enabling the rotation of the plate together with the shaft relative to the housing. The decoupler plate is also provided with a plurality of pinholes through the decoupler plate. The pinholes are spatially, circumferentially arranged on the decoupler plate to axially align with the alignment pins on the end plate. 
         [0015]    A coil spring is mounted on the shaft. The coil spring engages between an annular spring retainer at one end of the shaft and the decoupler plate. The spring exerts a biasing force on the decoupler plate that urges the decoupler plate in the second axial direction to the second position of the decoupler plate on the shaft. 
         [0016]    There are five electromagnets employed in the electromechanical decoupler. Each of the electromagnets is secured to the end plate of the housing in the interior volume of the housing. The plurality of electromagnets are spatially, circumferentially arranged around the coil spring. The electromagnets are operable to create magnetic fields between the electromagnets and the decoupler plate when activated. The magnetic field created pulls the decoupler plate against the bias force of a coil spring from the second position of the decoupler plate on the shaft to the first position of the decoupler plate on the shaft. The decoupler plate is held against the electromagnets by the magnetic fields created by the activated electromagnets. In the second position of the decoupler plate relative to the shaft and the housing, the alignment pins extend through the pin holes and the plate projections mesh with the housing projections. This positioning of the decoupler plate connects the decoupler plate to the housing. 
         [0017]    When the electromagnets are deactivated, the magnetic field between the electromagnets and the decoupler plate is extinguished. With the magnetic field extinguished, the coil spring pushes the decoupler plate in the second axial direction from the first position of the decoupler plate on the shaft, to the second position of the decoupler plate relative to the shaft. This disconnects the decoupler plate and the shaft from the housing. 
         [0018]    Manual control devices are connected to the housing. The manual control devices are operatively connected with flight controls of an aircraft, for example the control sticks and foot pedals. 
         [0019]    In use of the electromechanical decoupler, the electromagnets are activated creating magnetic fields between the electromagnets  132  and the decoupler plate. This draws the decoupler plate from its second position on the shaft to its first position on the shaft. If the alignment pins are not aligned with the pin holes of the decoupler plate, the manual control devices are manipulated to cause movement of the housing around the center axis until the alignment pins align with the pin holes. This movement also ensures that the manual control devices connected to the housing are properly indexed or positioned relative to the shaft. When the alignment pins align with the pin holes, the decoupler plate moves in the first axial direction on the shaft to its first position on the shaft. This causes the plate projections on the decoupler plate to mesh with the housing projections in the interior of the housing outer wall. This in turn causes the housing to be connected with the decoupler plate and the shaft. This also couples the manual control devices with the actuator. Manual manipulations of the manual control devices will cause the housing to move with the decoupler plate and the shaft, resulting in rotational movements of the shaft. 
         [0020]    During flight operations, if it is necessary to separate the pilot from excessive inertia forces being transmitted from the actuator through the mechanical decoupler to the manual control devices, the electromagnets are deactivated. This causes the coil spring to push the decoupler plate from its first position on the shaft to its second position on the shaft. This moves the plate projections on the decoupler plate out of meshing engagement with the housing projections on the housing. This disconnects the housing from the decoupler plate and the shaft. This in turn separates the manual control devices and the pilot manipulating those devices from the excessive inertia forces being transferred from the actuator to the shaft. This also enables the pilot to control the flight control surfaces of the aircraft by manipulation of the manual control devices without the assistance of the actuator. 
         [0021]    On cessation of the excessive inertia forces on the flight control surfaces of the aircraft, the electromagnets can again be activated. Activation of the electromagnets creates the magnetic field between the electromagnets and the decoupler plate. The magnetic field again moves the decoupler plate in the first axial direction from the second position of the decoupler plate on the shaft, to the first position of the decoupler plate on the shaft. With manual manipulation of the manual control devices, the alignment pins are aligned with the pin holes of the decoupler plate, permitting the decoupler plate to move to its first position on the shaft. This also properly indexes the manual control devices with the shaft of the actuator. With movement of the decoupler plate to its first position on the shaft, the plate projections on the decoupler plate mesh with the housing projections on the housing, thereby connecting the housing with the decoupler plate and the shaft. This also reconnects the operative connection between the manual control devices and the shaft of the actuator. 
         [0022]    The features, functions, and advantages that have been discussed can be achieved independently in various embodiments or may be combined in yet other embodiments, other details of which can be seen with reference to the following description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    Further features of the electromechanical decoupler are set forth in the following description of the decoupler and in the drawing figures. 
           [0024]      FIG. 1  is a representation of a control system for an aircraft. 
           [0025]      FIG. 2  is a representation of a perspective view of the electromechanical decoupler connected to an electromechanical actuator of the aircraft control system. 
           [0026]      FIG. 3  is a cross-section view of the electromechanical decoupler. 
           [0027]      FIG. 4  is a representation of a perspective view of the left side of the interior of the decoupler shown in  FIG. 3 . 
           [0028]      FIG. 5  is a representation of a perspective view of the right side of the interior of the decoupler as shown in  FIG. 3 . 
           [0029]      FIG. 6  is a representation of a cross-section view of a variation of the decoupler. 
           [0030]      FIG. 7  is a representation of a perspective view of a variation in a component part of the decoupler. 
           [0031]      FIG. 8  is a representation of a cross-section view of the decoupler. 
           [0032]      FIG. 9  is a representation of a perspective view of the left side of the interior of a variation of the decoupler. 
           [0033]      FIG. 10  is a representation of a flow chart of the method of using the electromagnetic decoupler. 
       
    
    
     DESCRIPTION 
       [0034]      FIG. 1  is a representation of a control system for an aircraft. In the representation of  FIG. 1 , the aircraft is a rotary-wing aircraft. A rotor  12  of the aircraft to which rotor blades (not shown) are attached is represented in  FIG. 1 . The rotor blades are operatively connected to a series of manual controls in the cockpit of the aircraft. 
         [0035]    The manual controls include manually manipulated control sticks  14  and foot pedals  16 . Manipulation of the control sticks  14  and foot pedals  16  controls the flight of the aircraft. The manual manipulation of the control sticks  14  and foot pedals  16  by a pilot is assisted by a series of actuators  22 . 
         [0036]    The actuators  22  are operatively connected with the control sticks  14  and foot pedals  16 . The actuators operate the rotor blades of the rotor  12  as well as other flight control surfaces of the aircraft in response to manual manipulation of the control sticks  14  and the food pedals  16 . 
         [0037]    Represented in  FIG. 1  are electromechanical decouplers  26  operatively connected between the actuators  22  and the control sticks  14  and food pedals  16  of the aircraft. In response to excessive inertia forces exerted on the rotor blades or other flight surfaces of the aircraft, the electromechanical decouplers  26  can be immediately actuated to separate the control sticks  14  and food pedals  16  from the actuators  22 , thereby separating the pilot from the excessive inertia forces. 
         [0038]      FIG. 2  is a representation of a perspective view of one of the electromechanical decouplers  26  connected to an actuator  22 .  FIG. 3  is a cross- section view of the electromechanical decoupler  26  in its uncoupled condition.  FIG. 4  is a representation of a perspective view of the left side of the interior of the decoupler as shown in  FIG. 3 .  FIG. 5  is a representation of a perspective view of the right side of the interior of the decoupler as shown in  FIG. 3 . 
         [0039]    The component parts of the decoupler  26  to be described are constructed of materials that provide the component parts with sufficient strength for the intended functioning of the decoupler. The component parts could be constructed of metal, or other equivalent materials. 
         [0040]    The electromechanical decoupler  26  is contained inside a housing  32 . The housing  32  has an outer wall  34  with a cylindrical configuration. The cylindrical configuration of the outer wall  34  has a center axis  36 . The center axis  36  defines mutually perpendicular axial and radial directions relative to the housing  32 . The outer wall  34  has an exterior surface  38  and a radially opposite interior surface  42 . The interior surface  42  surrounds an interior volume  44  of the housing. The housing  42  has an axial length that extends from a circular base edge  46  on the right side of the outer wall  34  as viewed in  FIG. 3  to a circular end edge  48  on the left side of the outer wall as viewed in  FIG. 3 . 
         [0041]    A plurality of housing projections  52  are provided on the interior surface  42  of the outer wall  34 . The plurality of housing projections  52  extend radially inwardly from the interior surface  42  and are arranged in a circle around the interior volume  44 . The circle of the housing projections  52  is coaxial with the center axis  36 . As represented in  FIGS. 3 and 4 , the projections  52  are configured as spur gear teeth that form a ring gear on the interior surface  42  of the housing  32 . Other equivalent configurations of the housing projections  52  could be employed in the electromechanical decoupler  26 . 
         [0042]    A base plate  54  is connected to the base edge  46  of the outer wall  34 . The base plate  54  is substantially flat and has a circular outer edge  56  that defines a circular configuration of the base plate  54 . As represented in  FIG. 3 , the outer edge  56  is co-extensive with the exterior surface  38  of the housing outer wall  34 . A center hole  58  extends through the base plate  54 . The center hole  58  is coaxial with the housing center axis  36 . 
         [0043]    An end plate  62  is connected to the end edge  48  of the housing outer wall  34 . The end plate  62  is substantially flat and has a circular outer edge  64  that defines a circular configuration of the end plate. The outer edge  64  of the end plate  62  is coextensive with the exterior surface of the housing outer wall  34 . The end plate  62  has a center hole  66  through the end plate. The center hole  66  of the end plate  62  is coaxial with the center axis  36 . Additionally, the center hole  66  through the end plate  62  is axially aligned with and has substantially the same diameter dimension as the center hole  58  through the base plate  54 . 
         [0044]    A plurality of alignment pins  68  are connected to the end plate  62 . As represented in  FIG. 3 , the alignment pins  68  extend through holes in the end plate  62  and into the interior volume  44  of the housing  32 . The alignment pins  68  could be attached to the end plate  62  in other equivalent manners. The alignment pins  68  are parallel and are spatially, circumferentially arranged around the center axis  36 . The alignment pins  68  are also radially positioned between the center hole  66  of the end plate  62  and the outer edge  64  of the end plate. As represented in the drawing figures, there are three alignment pins  68  equally spatially arranged around the center axis  36 . More or fewer than the three alignment pins  68  could be employed in the electromechanical decoupler  26 . 
         [0045]    A base plate bearing assembly  72  is mounted in the center hole  58  of the base plate  54 . An end plate bearing plate assembly  74  is mounted in the center hole  66  of the end plate  62 . The bearing assemblies  72 ,  74  represented in  FIG. 3  are ball bearing assemblies. Other equivalent types of bearing assemblies could be employed in the electromechanical decoupler  26 . 
         [0046]    A shaft  76  extends through the interior volume  44  of the housing  32 . The shaft  76  is coaxial with the center axis  36 . The shaft  76  is mounted in the base plate bearing assembly  72  and the end plate bearing assembly  74  for rotation of the shaft  76  around the center axis  36  of the housing  32 . As represented in  FIG. 3 , the shaft  76  extends completely through the housing  32  from a right hand end  78  of the shaft to a left hand end  82  of the shaft. The shaft  76  is represented as being hollow in  FIG. 3 , but the shaft could be solid. The shaft  76  has a cylindrical exterior surface  84 . An annular shoulder surface  86  is formed on the shaft exterior surface  84  adjacent the right hand end  78  of the shaft. The shoulder surface  86  engages against the base plate bearing assembly  72  and holds the shaft against axial movement in the interior volume  44  of the housing  32 . A screw thread  88  is formed on the exterior surface  84  of the shaft  76  adjacent the left hand end  82  of the shaft. A retainer ring  92  is threaded onto the screw thread  88  and engages against the end plate bearing assembly  74 . Together the shoulder surface  86  and the retainer ring  92  securely hold the shaft  76  in its axial position relative to the housing  32 . The shaft  76  also has a plurality of axial grooves  94  formed in the exterior surface  84  of the shaft. The axial grooves  94  are spatially, circumferentially arranged around the shaft  76 . 
         [0047]    A plurality of narrow, elongate guides  96  are positioned in the axial grooves  94  of the shaft  76 . The guides  96  each have straight axial lengths that extend across a portion of the exterior surface  84  of the shaft  76 . Additionally, each of the guides  96  have height dimensions that extend radially from the axial grooves  94  and outwardly from the exterior surface  84  of the shaft  76 . The positioning of the guides  96  in the shaft grooves  94  spatially, circumferentially arranges the guides  96  around the center axis  36 . In the representation of the electromechanical decoupler  26  shown in  FIG. 3 , the guides  96  are formed as splines positioned in the axial grooves  94 . Other equivalent types of guides  96  could be employed in place of the splines. For example, the splines  96  could be replaced by axial rows of ball bearings  98  as represented in  FIG. 6 . 
         [0048]    A decoupler plate  102  is mounted on the shaft  76 . The decoupler plate  102  is substantially flat and has a circular outer edge  104  that gives the decoupler plate  102  a circular configuration. The decoupler plate outer edge  104  is formed with a plurality of plate projections  106  that extend radially outwardly from the outer edge. The plate projections  106  are complementary to the housing projections  52 . The complementary configurations of the plate projections  106  and the housing projections  52  enables the decoupler plate  102  to be positioned in the same plane as the housing projections  52 . In the electromechanical decoupler  26  represented in  FIG. 3 , the plate projections  106  have the configuration of spur gear teeth. Other configurations of the plate projections  106  could also be employed in the electromechanical decoupler  26 . For example, the decoupler plate could have axially projecting teeth  108  such as those represented in  FIG. 7 . The decoupler plate  102  has a center hole  110  that is coaxial with the center axis  36 . The center hole  110  is dimensioned to receive the exterior surface  84  of the shaft  76  in the center hole. A plurality of axial grooves  112  are formed in the center hole  110  of the decoupler plate  102 . The grooves  112  are spatially, circumferentially arranged around the center hole  110 . The positions of the grooves  112  correspond to the positions of the guides  96  in the axial grooves  94  of the shaft  76 . The engagement of the guides  96  in the grooves  112  of the center hole  110  of the decoupler plate  102  mounts the decoupler plate  102  to the shaft  76  and secures the decoupler plate  102  against rotation relative to the shaft  76 , but enables axial movement of the decoupler plate  102  over the shaft  76 . The decoupler plate  102  is mounted by the guides  96  to the shaft  76  for movement of the decoupler plate  102  in opposite first and second axial directions between a first position of the decoupler plate  102  relative to the housing  32  represented in  FIG. 8 , to a second position of the decoupler plate  102  relative to the housing  32  represented in  FIG. 3 . In the first position of the decoupler plate  102  relative to the housing  32 , the plate projections  106  of the decoupler plate  102  are meshed with the housing projections  52  of the housing  32  as represented in  FIG. 8 , thereby connecting the decoupler plate  102  to the housing  32 . In the second position of the decoupler plate  102  relative to the housing  32  represented in  FIG. 3 , the plate projections  106  on the decoupler plate  102  are moved out of mesh with the housing projections  52  of the housing  32 , thereby disconnecting the decoupler plate  102  from the housing and enabling rotation of the decoupler plate  102  together with the shaft  76  relative to the housing  32 . The decoupler plate  102  is also provided with a plurality of pin holes  114  through the decoupler plate. The pin holes  114  are spatially, circumferentially arranged around the center hole  110  of the decoupler plate  102 . The pin holes  114  are also radially positioned on the decoupler plate  102  to axially align with the alignment pins  68  on the end plate  62 . The decoupler plate  102  has a spring groove  116  radially within the pin holes  114 . The spring groove  116  is annular and extends completely around the shaft  76  and the center axis  36 . 
         [0049]    A biasing device such as a coil spring  118  is mounted on the shaft  76  in the interior volume  44  of the housing  32 . As represented in  FIG. 3 , the coil spring  118  extends between an annular spring retainer  122  that engages against the end plate bearing assembly  74 , to the spring groove  116  in the decoupler plate  102 . The coil spring  118  engaging between the spring retainer  122  and the spring groove  116  of the decoupler plate  102  exerts a biasing force on the decoupler plate  102  that urges the decoupler plate in the second axial direction to the second position of the decoupler plate  102  relative to the housing  32  represented in  FIG. 3 . Although a coil spring  118  is represented as the biasing device in  FIG. 3 , other equivalent types of biasing devices could be employed in the electromechanical decoupler  26  that exert a biasing force on the decoupler plate  102  and urge the decoupler plate to its second position relative to the housing  32 . For example, the coil spring  118  could be replaced by a plurality of coil springs  124  spatially, circumferentially arranged around the shaft  76  as represented in  FIG. 9 . 
         [0050]    A plurality of electromagnets  132  are provided in the interior volume  44  of the housing  32 . Each of the electromagnets  132  is secured to the end plate  62  of the housing  32  in the interior volume  44  of the housing. As represented in  FIG. 4 , there are five electromagnets  132  spatially, circumferentially arranged around the coil spring  118 . Other numbers of electromagnets  132  could be employed in the electromechanical decoupler  26 . Each of the electromagnets  132  has a cylindrical configuration. Each of the electromagnets  132  extends from the end plate  62  axially into the housing a distance that spaces end  136   132  of the electromagnets  132  just short of the ring of housing projections  52 . The electromagnets  132  are operable to create magnetic fields between the end surfaces  134  and the decoupler plate  102  when activated. The magnetic fields created pull the decoupler plate  102  against the bias force of the coil spring  118  from the second position of the decoupler plate  102  on the shaft  76  represented in  FIG. 3 , to the first position of the decoupler plate  102  on the shaft  76  represented in  FIG. 8 . As represented in  FIG. 8 , the decoupler plate  102  is held against the end surfaces  134  of the electromagnets  132  by the magnetic fields created by the activated electromagnets  132 . In the position of the decoupler plate  102  relative to the shaft  76  and the housing  32 , the alignment pins  68  extend through the pin holes  114  and the plate projections  106  mesh with the housing projections  52 . This positioning of the decoupler plate  102  connects the decoupler plate to the housing  32 . 
         [0051]    When the electromagnets  132  are deactivated, the magnetic fields between the electromagnets  132  and the decoupler plate  102  are extinguished. With the magnetic fields extinguished, the coil spring  118  pushes the decoupler plate  102  in the second axial direction from the first position of the decoupler plate  102  on the shaft  76  represented in  FIG. 8 , to the second position of the decoupler plate  102  relative to the shaft  76  represented in  FIG. 3 . This disconnects the decoupler plate  102  and the shaft  76  from the housing  32 . 
         [0052]    Manual control devices  142 ,  144  are connected to the housing  32  as represented in  FIG. 2 . The manual control devices  142  are operatively connected with flight controls of an aircraft, for example the control sticks  14  and foot pedals  16  represented in  FIG. 1 . 
         [0053]    According to the method of using the electromechanical decoupler  26  of this disclosure, the electromechanical decoupler  26  allows a pilot to maintain control of mechanical flight controls of a control system of an aircraft when a parallel electromechanical actuator of the control system fails, or when the electromechanical actuator when in a passive mode is back driven resulting in higher than acceptable flight control forces being transmitted by the mechanical flight controls to the pilot. 
         [0054]    Referring to  FIG. 1 , a control system for an aircraft is represented. The control system employs several of the electromechanical decouplers  26  operatively connected between actuators  22  of the control system and parallel mechanical flight controls such as manually manipulated control sticks  14  and foot pedals  16 . During flight of the aircraft with the actuators  22  turned on, the actuators  22  assist the pilot in the manual manipulation of the control sticks  14  and foot pedals  16  and provide the pilot with feedback on the loads exerted on the flight control surfaces of the aircraft through the control sticks  14  and foot pedal  16 . The feedback is transmitted from the actuators  22  through the electromechanical decouplers  26  to the control sticks  14  and foot pedals  16 . 
         [0055]    In use of the electromechanical decouplers  26  to operatively connect the control sticks  14  and foot pedals  16  in parallel with their associated actuators  22 , the electromagnets  132  are activated creating magnetic fields between the electromagnets  132  and the decoupler plate  102 . This draws the decoupler plate  102  from its second position on the shaft  76  represented in  FIG. 3 , to its first position on the shaft  76  represented in  FIG. 8 . If the alignment pins  68  are not aligned with the pin holes  114  of the decoupler plate  102 , the manual control devices  142 ,  144  are manipulated by manually manipulating the control sticks  14  and foot pedals  16  to cause movement of the housing  32  around the center axis  36  until the alignment pins  68  align with the pin holes  114 . This movement also ensures that the manual control devices  142 ,  144  connected to the housing  32  are properly indexed or positioned relative to the shaft  76 . When the alignment pins  68  align with the pin holes  114 , the decoupler plate  102  moves in the first axial direction on the shaft  76  to its first position on the shaft represented in  FIG. 8 . This causes the plate projections  106  on the decoupler plate  102  to mesh with the housing projections  52  in the interior of the housing outer wall  34 . This in turn causes the housing  32  to be connected with the decoupler plate  102  and the shaft  76 . This also couples the manual control devices  142 ,  144  with the actuator  22 . In this manner, each of the control sticks  14  and foot pedals  16  of the aircraft control system represented in  FIG. 1  is operatively connected through an electromechanical decoupler  26  with its associated actuator  22  movements of the control sticks  14  and foot pedals  16  are transmitted through their associated manual control devices  142 ,  144  and cause the housing  32  connected to the control devices  142 ,  144  to move with the decoupler plate  102  and the shaft  76 , resulting in rotational movements of the shaft  76 . 
         [0056]    According to the method of using the electromagnetic decouplers  26  of this disclosure, the decouplers  26  allow the pilot to maintain control of the mechanical flight controls such as the control sticks  14  and foot pedals  16  when a parallel actuator  22  fails or when excessive forces on the flight control surfaces of the aircraft backdrive the actuator  22  in a passive mode resulting in higher than acceptable flight control forces being transmitted to the pilot. During flight operations, if it is necessary to separate the pilot from excessive inertia forces being transmitted from an actuator  22  through the electromechanical decoupler  26  to the manual control devices  142 ,  144  and their associated control sticks  14  or foot pedals  16  to the pilot of the aircraft, the electromagnets  132  are deactivated. The deactivation of the electromagnets  132  could be in response to a signal generated by a sensor associated with the actuator  22  that senses an excessive back driving force transmitted from a flight control surface of the aircraft to the actuator  22 . The deactivation of the electromagnets  132  causes the coil spring  118  to push the decoupler plate  102  from its first position on the shaft  76  represented in  FIG. 8 , to its second position on the shaft  76  represented in  FIG. 3 . This moves the plate projections  106  on the decoupler plate  102  out of meshing engagement with the housing projections  52  on the housing  32 . This disconnects the housing  32  from the decoupler plate  102  and the shaft  76 . This in turn separates the manual control devices  142 ,  144  and their associated control sticks  14  and foot pedals  16  and the pilot manipulating those devices from the excessive inertia forces being transferred from the actuator  22  to the shaft  76 . This also enables the pilot to control the flight control surfaces of the aircraft by manipulation of the manual control sticks  14  and foot pedals  16  and their associated control devices  142 ,  144  without the assistance of the actuator  22 . 
         [0057]    On cessation of the excessive inertia forces on the flight control surfaces of the aircraft, the electromagnets  132  can again be activated. Activation of the electromagnets  132  creates the magnetic fields between the electromagnets  132  and the decoupler plate  102 . The magnetic fields again move the decoupler plate  102  in the first axial direction from the second position of the decoupler plate  102  on the shaft  76  represented in  FIG. 3 , to the first position of the decoupler plate  102  on the shaft  76  represented in  FIG. 8 . With manual manipulation of the manual control devices  142 ,  144 , the alignment pins  68  are aligned with the pin holes  114  of the decoupler plate  102 , permitting the decoupler plate  102  to move to its first position on the shaft  76 . This also properly indexes the manual control devices  142 ,  144  with the shaft  76  of the actuator  22 . With movement of the decoupler plate  102  to its first position on the shaft  76 , the plate projections  106  on the decoupler plate  102  mesh with the housing projections  52  on the housing  32 , thereby connecting the housing  32  with the decoupler plate  102  and the shaft  76 . This also reconnects the operative connection between the manual control devices  142 ,  144  and the shaft  76  of the actuator  22 . 
         [0058]    As various modifications could be made in the construction of the apparatus and its method of operation herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present disclosure should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.