Patent Publication Number: US-10316904-B2

Title: Coupling assembly having an overrun mode and appendaged locking member for use therein

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional application Ser. No. 62/400,724 filed Sep. 28, 2016, the disclosure of which is hereby incorporated in its entirety by reference herein. 
    
    
     TECHNICAL FIELD 
     This invention relates in general to the field of coupling assemblies having an overrun mode and locking members such as struts for use therein. 
     Overview 
     As described in U.S. Pat. No. 8,844,693 (i.e., see,  FIG. 6  herein which corresponds to FIG. 3 of the patent), overrunning coupling assemblies may be used for transferring torque from a driving member to a driven member in a variety of structural environments. This permits the transfer of torque from a driving member to a driven member while permitting freewheeling motion of the driving member relative to the driven member when torque is interrupted. Such couplings often comprise an outer race concentrically disposed with respect to an inner race, the outer race having cammed surfaces that define a pocket in which coupling rollers are assembled. 
     The driving member is connected to one race, and the driven member is connected to the other race. During torque transfer from the driving member to the driven member, the rollers become locked with a camming action against the cam surfaces, thereby establishing a positive driving connection between the driving member and the driven member. When the torque is interrupted, the driven member may freewheel relative to the driving member as the rollers become unlocked from their respective cam surfaces. 
     Another common overrunning coupling includes overrunning coupling sprags disposed between the inner cylindrical surface of an outer race and the outer cylindrical surface of an inner race so that the sprags lock the races together as torque is delivered to the driven member. The sprags become unlocked with respect to the inner and outer race surfaces when torque transfer is interrupted. 
     A pocket plate may be provided with angularly disposed recesses or pockets about the axis of a one-way clutch. The pockets are formed in the planar surface of the pocket plate. Each pocket receives a torque transmitting strut, one end or tail of which engages an anchor point in a pocket of the pocket plate. An opposite edge of the strut, which may hereafter be referred to as an active edge or nose, is movable from a position within the pocket to a position in which the active edge extends outwardly from the planar surface of the pocket plate. The struts may be biased away from the pocket plate by individual springs. 
     A notch plate may be formed with a plurality of recesses or notches located approximately on the radius of the pockets of the pocket plate. The notches are formed in the planar surface of the notch plate. 
     Another example of an overrunning planar clutch is disclosed in U.S. Pat. No. 5,597,057. 
     Other U.S. patents related to the present invention include: U.S. Pat. Nos. 5,070,978; 5,449,057; 5,806,643; 5,871,071; 5,918,715; 5,964,331; 5,927,455; 5,979,627; 6,065,576; 6,116,394; 6,125,980; 6,129,190; 6,186,299; 6,193,038; 6,244,965; 6,386,349; 6,481,551; 6,505,721; 6,571,926; 6,854,577; 7,258,214; 7,275,628; 7,344,010; and 7,484,605. 
     As disclosed in  FIG. 1 , (i.e. FIG. 10 of U.S. Pat. No. 6,186,299), a strut pocket is sufficiently enlarged in a direction forward of the front edge of the strut to allow sliding movement of the strut from the position shown in phantom to the overrun position shown in solid lines wherein the forward corner of the strut engages the outer circumferential rail of the notch plate during overrunning to prevent the struts from slapping against the notch recesses during overrunning. Each strut pocket provides sufficient clearance forward of the respective opposite edge of the strut to allow forward sliding movement of the respective strut during overrunning to cause the engagement of the respective spring and strut to occur nearer the ear axis, thereby reducing the length of a moment arm about which the spring acts upon the strut. 
     Yet still other related U.S. patents include: U.S. Pat. Nos. 4,200,002; 5,954,174; and 7,025,188. 
     More recent related patent documents include U.S. Pat. Nos. 7,100,756; 7,223,198; 7,383,930; 7,448,481; 7,451,862; 7,455,156; 7,455,157; 7,450,548; 7,614,486; 7,661,518; 7,743,678; 7,942,781; 7,980,372; 7,992,695; 8,042,669; 8,042,670; 8,051,959; 8,056,690; 8,079,453; 8,083,042; 8,091,696; 8,491,439; 8,646,587; 8,720,659; 8,844,693; 8,881,516; 8,986,157; 9,121,454; 9,186,977; 9,188,170; 9,188,172; and 9,188,174. Also included are published U.S. patent applications Nos. 2008/0110715; 2011/0269587; 2011/0183806; 2011/0214962; 2011/0297500; 2008/0169165; 2009/0159391; 2010/0288592; 2014/0116832; 2014/0190785; and 2016/0230819. 
     As disclosed in  FIGS. 2 and 3  (i.e. FIGS. 8 and 10 of U.S. Pat. No. 9,121,454), a locking member for controllably transmitting torque between first and second coupling members of a coupling assembly is shown. The locking member includes projecting inner and outer pivots which extend laterally from a main body portion for enabling pivotal motion of the locking member about a pivot axis which intersects the pivots. The pivots are sized, shaped and located with respect to the main body portion to allow frictional engagement of an end surface of the outer pivot with an outer wall of a pocket to occur near the pivot axis during rotation of the first coupling member and the locking member above a predetermined RPM thereby reducing overall moment on the locking member about the pivot axis that has to be overcome to move the locking member between the engaged and disengaged positions. 
       FIGS. 4, 5   a  and  5   b  (i.e. FIGS. 4 a  and 2, respectively, of U.S. 2016/0160942) discloses a selectable one-way clutch (i.e. SOWC) configured to prevent an unintentional engagement. A pawl comprises a strut that is pushed up toward a notch through an aperture of a selector plate, a stopper plate protruding laterally from a rear end side of the strut, and a first inclined face formed on the stopper plate to incline downwardly from the rear end side toward the leading end side of the strut. A side plate is formed along each long side of the aperture to protrude toward the pocket plate, and the second inclined face is formed on the side plate to be brought into contact to the first inclined face. 
     Metal injection molding (MIM) is a metalworking process where finely-powdered metal is mixed with a measured amount of binder material to comprise a “feedstock” capable of being handled by plastic processing equipment through a process known as injection mold forming. The molding process allows complex parts to be shaped in a single operation and in high volume. End products are commonly component items used in various industries and applications. The nature of MIM feedstock flow is defined by a physics called rheology. Current equipment capability requires processing to stay limited to products that can be molded using typical volumes of 100 grams or less per “shot” into the mold. Rheology does allow this “shot” to be distributed into multiple cavities, thus becoming cost-effective for small, intricate, high-volume products which would otherwise be quite expensive to produce by alternate or classic methods. The variety of metals capable of implementation within MIM feedstock are referred to as powder metallurgy, and these contain the same alloying constituents found in industry standards for common and exotic metal applications. Subsequent conditioning operations are performed on the molded shape, where the binder material is removed and the metal particles are coalesced into the desired state for the metal alloy. 
     For purposes of this application, the term “coupling” should be interpreted to include clutches or brakes wherein one of the plates is drivably connected to a torque delivery element of a transmission and the other plate is drivably connected to another torque delivery element or is anchored and held stationary with respect to a transmission housing. The terms “coupling”, “clutch” and “brake” may be used interchangeably. 
     A “moment of force” (often just moment) is the tendency of a force to twist or rotate an object. A moment is valued mathematically as the product of the force and a moment arm. The moment arm is the perpendicular distance from the point or axis of rotation to the line of action of the force. The moment may be thought of as a measure of the tendency of the force to cause rotation about an imaginary axis through a point. 
     In other words, a “moment of force” is the turning effect of a force about a given point or axis measured by the product of the force and the perpendicular distance of the point from the line of action of the force. Generally, clockwise moments are called “positive” and counterclockwise moments are called “negative” moments. If an object is balanced then the sum of the clockwise moments about a pivot is equal to the sum of the counterclockwise moments about the same pivot or axis. 
     SUMMARY OF EXAMPLE EMBODIMENTS 
     An object of at least one embodiment of the present invention is to provide a coupling assembly having an overrun mode and an appendaged locking member for use in the assembly wherein a higher torque-locked assembly can be disengaged with lower force. 
     In carrying out the above object and other objects of at least one embodiment of the present invention, a coupling assembly having an overrun mode is provided. The assembly includes first and second members including first and second coupling faces, respectively, in close-spaced opposition with one another. At least one of the members is mounted for rotation about an axis. A locking member is disposed between the coupling faces of the first and second members. The locking member is movable between coupling and uncoupling positions. A control element is mounted for controlled movement between the coupling faces and is operable to control position of the locking member. The locking member includes a first member-engaging nose, a second member-engaging tail diametrically opposite the nose and a main body between the nose and the tail. The main body has upper and lower faces. The locking member further includes a control element-engaging appendage which extends downwardly from the lower face and a pair of oppositely projecting pivots which extend laterally from the tail for enabling pivotal motion of the locking member about a pivot axis which intersects the pivots. The control element engages the appendage to create a moment of the locking member about the pivot axis to urge the locking member from the coupling position towards the uncoupling position. The coupling position is characterized by abutting engagement of the nose with the first member to allow one-way torque transfer to occur between the first and second members. The uncoupling position is characterized by non-abutting engagement of the nose with the first member. The moment decreases the amount of force needed by the control element to move the locking member out of the coupling position. 
     The control element may have at least one opening which extends completely therethrough to allow the locking member to extend therethrough to the coupling position in a control position of the control element. 
     The appendage may include a pair of oppositely projecting ears which extend laterally. 
     One of the first and second members may be a notch plate and the other of the first and second members may be a pocket plate. 
     The assembly may be a controllable or selectable one-way clutch assembly. 
     The appendage may be centrally located between side faces of the main body and may have a face which inclines downwardly away from the tail. 
     The control element may be a control or selector plate rotatable about the axis. 
     The assembly may further include a biasing member carried by the second member to urge the locking member toward the coupling position. 
     The appendage may include oppositely projecting ramp portions which extend laterally. Each of the ramp portions may have a face which inclines upwardly toward the tail. 
     The control element may be either non-planar or planar. 
     Further in carrying out the above object and other objects of at least one embodiment of the present invention, a locking member for a coupling assembly including first and second coupling members and a control element is provided. The locking member includes a first member-engaging nose, a second member-engaging tail diametrically opposite the nose and a main body between the nose and the tail. The main body has upper and lower faces. The locking member also includes a control element-engaging appendage which extends downwardly from the lower face and a pair of oppositely projecting pivots which extend laterally from the tail for enabling pivotal motion of the locking member about a pivot axis which intersects the pivots. The control element engages the appendage to create a moment of the locking member about the pivot axis to urge the locking member from a coupling position towards an uncoupling position. The coupling position is characterized by abutting engagement of the nose with the first coupling member to allow one-way torque transfer to occur between the coupling members. The uncoupling position is characterized by non-abutting engagement of the nose with the first coupling member. The moment decreases the amount of force needed by the control element to move the locking member out of the coupling position. 
     The locking member may be a strut. 
     An end of the tail may be canted. 
     The strut may be a ratchet strut. 
     The appendage may include a pair of oppositely projecting ears which extend laterally. 
     The appendage may be centrally located between side faces of the main body and may have a face which inclines downwardly away from the tail. 
     The appendage may include oppositely projecting ramp portions which extend laterally. Each of the ramp portions may have a face which inclines upwardly toward the tail. 
     The locking member may be an injection molded locking member such as a metal injection molded locking member. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view, partially broken away, of a prior art pocket plate and a strut slidable within a pocket of the plate; 
         FIG. 2  is a side view, partially broken away and in cross section, of a prior art coupling assembly with a locking member or strut shown in its uncoupling position; 
         FIG. 3  is a view similar to the view of  FIG. 2 , with the strut in its locking position; 
         FIG. 4  is a side view, partially broken away and in cross section, of a prior art coupling assembly with its strut in its uncoupling position; 
         FIG. 5A  is a bottom perspective view, partially broken away, of a selector plate of the assembly of  FIG. 4 ; 
         FIG. 5B  is a top perspective view of the strut of the assembly of  FIG. 4 ; 
         FIG. 6  is a side view, partially broken away, of a prior art coupling assembly with a locking member of the assembly extending between driving and driven numbers of the assembly; 
         FIG. 7A  is a side view, partially broken away and in cross section, of a coupling assembly (without its notch plate) with a locking member constructed in accordance with at least one embodiment of the present invention extending through an apertured control element; 
         FIG. 7B  is a view similar to the view of  FIG. 7A , but showing the locking member in is uncoupling position, having been rotated by the control element; 
         FIG. 7C  is a top perspective view of the locking member of  FIGS. 7A and 7B ; 
         FIG. 8A  is a side view, partially broken away and in cross section, of a second embodiment of the coupling assembly (without its notch plate) with its biased locking member extending through its apertured control element; 
         FIG. 8B  is a top perspective view of the locking member of  FIG. 8A ; 
         FIG. 8C  is a side view, partially broken away, of two alternative embodiments of the control element of  FIG. 8A ; 
         FIG. 8D  is a side elevational view of the locking member of  FIGS. 8A-8C ; 
         FIG. 8E  is a top plan view of the control element of  FIG. 8A ; 
         FIG. 8F  is an enlarged view contained within the dashed circle of  FIG. 8E  and illustrating an aperture of the control element; 
         FIG. 8G  is a view, partially broken away and in cross section, of the control element taken along lines  8 G- 8 G of  FIG. 8F ; 
         FIG. 8H  is a top plan view, partially broken away, of a portion of the pocket plate of  FIG. 8A ; 
         FIG. 9A  is a side view, partially broken away, of a third embodiment of a locking member and a control element; 
         FIG. 9B  is a top perspective view, partially broken away, of the locking member and control element of  FIG. 9A ; 
         FIG. 9C  is a top perspective view of the locking member of  FIGS. 9A and 9B ; 
         FIG. 9D  is a side elevational view of the locking member of  FIGS. 9A-9C . 
         FIG. 9E  is a top plan view of the control element of  FIGS. 9A and 9B ; 
         FIG. 9F  is an enlarged view of an aperture contained within the dotted circle of  FIG. 9E ; 
         FIG. 9G  is a view, partially broken away and in cross section, of the control element taken along lines  9 G- 9 G in  FIG. 9F ; 
         FIG. 9H  is a top plan view, partially broken away, of a pocket plate for use with the control element and locking member of  FIGS. 9A-9G ; 
         FIG. 10A  is a top perspective view, partially broken away, of a further embodiment of a coupling assembly (without its notch plate) with its locking member in its coupling position; 
         FIG. 10B  is a top perspective view of the locking member of  FIG. 10A ; 
         FIG. 10C  is a side elevational view of the locking member of  FIGS. 10A and 10B ; 
         FIG. 10D  is a top plan view of an apertured control element used in the coupling assembly of  FIG. 10A ; 
         FIG. 10E  is an enlarged view of a portion of the control element appearing within the dotted circle  10 E in  FIG. 10D ; and 
         FIG. 10F  is a view, partially broken away and in cross section, of the control element taken along lines  10 F- 10 F in  FIG. 10E . 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
       FIGS. 7A, 7B and 7C  show a pocket member or plate, generally indicated at  10 , of a planar or overrunning coupling or clutch assembly, and constructed in accordance with at least one embodiment of the present invention. A coupling or notch plate of the assembly is typically nested within the pocket plate  10  and, while not shown in drawing  FIGS. 7A-10F , is generally of the type illustrated in  FIGS. 2, 3, 4 and 6  at reference numeral  14 . The notch plate  14  may be connected to a part (not shown) via internal splines formed on the notch plate  14 , which engage splines on the part. The pocket plate  10  may be typically provided with external splines. 
     An actuator (not shown) may be drivably connected to an apertured slide or control element or plate, generally indicated at  20 , thereby causing the control plate  20  to be adjusted angularly with respect to a central axis about which at least one of the plates  14  and  10  is rotatable. The control plate  20  is disposed between the plates  10  and  14  for limited angular rotation relative to the plates  10  and  14 , as generally illustrated in U.S. Pat. No. 7,344,010. 
     The control element or plate  20  is typically not a full circular part thereby requiring less material to manufacture the part. Hence, the parts  10 ,  14  and  20  can be nested closer together during a stamping assembly operation. Also, because the control plate  20  is not fully circular, it is easier to install into the clutch assembly. 
     The plate  14  can free-wheel in one angular direction about the central axis relative to the plate  10 . The one-directional, free-wheeling motion is achieved in an operating mode when the actuator adjusts the angular position of the control plate  20  relative to the pocket plate  10  (such as via a fork) about the central axis to a forward position which is obtained by moving the control plate  20  angularly a few degrees (such as 10°) from its reverse position. 
     The notch plate  14  typically has an inside or reference surface or coupling face with one or more notches formed therein and separated by common walls. The notch plate  14  may be adapted to be received in the pocket plate  10  as previously mentioned. 
     The pocket plate  10  has an inside surface  30  with forward recesses (not shown) and reverse pockets or recesses  33  formed in corresponding pawl-holding portions of the plate  10 . Located intermediate the inside surfaces of the plate  14  and the plate  10 , respectively, is the control plate  20 . 
     In one embodiment, there may be nineteen struts or pawls received and retained in the nineteen recesses (twelve forward recesses and seven reverse recesses  33 ) in the pocket plate  10 . Twelve of the pawls are “eared” forward pawls (not shown) for transferring torque in a forward direction about the central axis and seven of the pawls are “eared” reverse pawls, generally indicated  34 , clustered or grouped closely together in a curved row or line for preventing rotation between the members  10  and  14  in the “reverse” direction about the central axis. Each of the “eared” forward struts or pawls include a planar substantially rectangular portion and a pair of ears, as generally shown in U.S. Pat. No. 6,065,576. 
     Referring to  FIGS. 7A, 7B and 7C , each of the reverse pawls or struts  34  includes a first end surface or face  36  at a nose end  39  of the strut  34 . The strut  34  further includes a second end surface or face  38  at a tail end  41  of the strut  34  diametrically opposite the first end surface  36 . The tail end  41  engages a shoulder  37  in the plate  10 . The strut  34  further includes upper and lower faces  40  and  42 , respectively, of a main body portion  43  of the strut  34   
     The strut  34  also includes a control element-engaging appendage, generally indicated at  44 , which extends downwardly from the lower face  42  of the main body  43  towards the nose  39  and away from the tail  41 . The control element  20  exerts a force on the appendage  44  when the control element  20  is rotated and the strut  34  extends through an aperture  46  in the plate  20  to create a moment of the locking member  34  about a pivot axis which intersects pivots  68  of the locking member or strut  34 . This movement urges the locking member or strut  34  towards an uncoupling position (i.e.  FIG. 7B ) characterized by non-abutting engagement of the nose  39  with the first member of plate  14  upon rotation (i.e. in a first direction) of the plate  14  relative to the plate  10  to prevent abutting engagement of the strut  34  with a shoulder  45  ( FIGS. 2, 3, 4 and 6 ) of the plate  14  in the overrun mode. 
     A second embodiment of the invention is shown in drawing  FIGS. 8A-8H . The third embodiment of the invention is shown in drawing  FIGS. 9A-9H . The fourth embodiment of the invention is shown in drawing  FIGS. 10A-10F . The reference numbers for each of the embodiments are the same except in the second, third and fourth embodiments a single, double or triple prime designation, respectively, are provided to indicate parts or portions which are the same or similar in either structure or function as in the first embodiment of  FIGS. 7A-7C . 
     For example, in the first and second embodiments of  FIGS. 7A-8H , the appendage  44  or  44 ′ is centrally located between side faces  50  and  52 , or  50 ′ and  52 ′ of the main body  43  or  43 ′ and has a control element-engaging face  45  or  45 ′ which inclines downwardly away from the tail  41  or  41 ′, respectively. 
     In the third embodiment of  FIGS. 9A-9H , the appendage  44 ″ includes oppositely projecting ramp portions  48 ″ which extend laterally. Each of the ramp portions  48 ″ has a control element engaging face  49 ″ which inclines upwardly toward the tail  41 ″. 
     In the fourth embodiment of  FIGS. 10A-10F , the appendage  44 ′″ includes a pair of oppositely projecting ears  48 ′″ which extend laterally and have control element-engaging faces  49 ′″ on their opposite sides. 
     The third and fourth embodiments allow either forward or reverse selector plate motion to disengage their respective struts  34 ″ and  34 ′, respectively, from their coupling positions. 
     In the embodiment of  FIG. 8C , the left-hand side of the Figure shows a bent or non-planar control element  20 ′ and the right-hand side of the Figure shows an alternative planar control element  21 ′ having a support rod  23 ′ welded to the lower surface of the element  21 ′ so the element  21 ′ need not be bent or shaped like the element  20 ′. 
     When the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) is situated in its “forward” position it covers the “reverse” set of clustered pawls or struts  34  (or  34 ′ or  34 ″ or  34 ′″). When the control plate  20  is situated in the “reverse” position it does not cover the “reverse” set of clustered struts  34 . When uncovered, the “reverse” struts  34  are allowed to ratchet. The reverse struts  34  ( 34 ′ or  34 ″ or  34 ′″) prevent rotation between the pocket plate  10  (or  10 ′ or  10 ″) and notch plate  14  in the “reverse” direction. (A pocket plate is not shown for the fourth embodiment but is substantially similar to the pocket plates of the other drawing figures.) 
     In the example described above, the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) is preferably provided with seven clustered or grouped apertures  46  (or  46 ′, or  46 ″ or  46 ′″). These are spaced and arranged angularly about the central axis of assembly rotation. When the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) is appropriately positioned in a “reverse” position, one aperture  46  (or  46 ′, or  46 ″ or  46 ′″) will be disposed directly over each recess  33  (or  33 ′ or  33 ″). 
     The apertures  46  (or  46 ′, or  46 ″ or  46 ′″) and the notches  28  are sized so that portions of the reverse pawls  34  (or  34 ′, or  34 ″ or  34 ′″) can enter the notches  28  of pawl-receiving portions of the notch plate  14  and engage shoulders  45  of the notches  28  to establish a locking action between the reverse pawls  34  (or  34 ′, or  34 ″ or  34 ′″) and the plate  14  that will prevent rotation between the plate  14  and the plate  10  (or  10 ′ or  10 ″). 
     When control plate  20  (or  20 ′, or  20 ″ or  20 ′″) is rotated to a different (i.e. forward) angular position from the reverse position, a portion of the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) about its aperture  46  engages a face or surface of the appendage  44  (or  44 ′, or  44 ″ or  44 ′″) of the pawls to cause the reverse pawls  34  (or  34 ′, or  34 ″ or  34 ′″) to rotate downwardly about a pivot axis of their pivots  68  into their recesses  33  (or  33 ′, or  33 ″ or  33 ′″) and will be at least partially covered by the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) and prevented from moving pivotally upward at an engagement point. When the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) is thus positioned, the plate  14  can free-wheel about the central axis with respect to the plate  10  (or  10 ′, or  10 ″). 
     The “eared” forward pawls are typically not covered by the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) but only by the notch plate  14 . The forward pawls typically may rotate outwardly while being partially held by the notch plate  14 . 
     The reverse pawls or struts  34  (or  34 ′, or  34 ″ or  34 ′″) each have the pair of oppositely projecting pivots  68  (or  68 ′, or  68 ″ or  68 ′″) which extend laterally from their tails  41  (or  41 ′, or  41 ″ or  41 ′″) and define the pivot axis of the struts  34 . 
     Although any suitable strut spring can be used with each embodiment of the invention, a coil spring  64 ′ ( FIG. 8A ) is typically located under each of the forward pawls and the reverse pawls  34  (or  34 ′, or  34 ″ or  34 ′″) within recesses  66 ′ ( FIG. 8H ) or  66 ″ ( FIG. 9H ) formed in the recesses  33 ′ or  33 ″, respectively. 
     When the notch plate  14  is received within or nested within the pocket plate  10  (or  10 ′ or  10 ″) with the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) therebetween, the plates  10  (or  10 ′ or  10 ″) and  14  are typically held axially fast by a retainer ring or snap-ring (not shown). The snap-ring is received and retained in a groove formed in the plate  10  (or  10 ′ or  10 ″). When assembled, the control plate  20  (or  20 ′, or  20 ″ or  20 ′″) is typically located within an annular groove (not shown) formed in the pocket plate  10  (or  10 ′ or  10 ″). 
     The reverse struts  34  (or  34 ′, or  34 ″ or  34 ′″) may be formed from a length of thin, cold-formed stock material, such as a cold-drawn or cold-rolled wire or spheroidized and annealed SAE 1065 steel. Each strut  34  (or  34 ′, or  34 ″ or  34 ′″) may be tumbled to achieve a suitable edge corner break, such as a maximum of 0.015 inches; hardened at 1550° F.; oil quenched; and tempered at 350° F. to a minimum hardness of 53 Rockwell-C. Alternatively, the reverse struts may be formed via metal injection molding. 
     It is to be understood that instead of the coupling assemblies disclosed above, another embodiment of a coupling assembly having radial ratchets may also be provided wherein the shape of the radial ratchets and notch tips are preferably ellipsoids. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.