Patent Publication Number: US-2023150401-A1

Title: Recliner handle with overload protection device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and all the benefits of U.S. Provisional Application 63/011,604, filed Apr. 17, 2020, and entitled “Recliner Handle With Overload Protection Device”, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a recliner handle configured to unlock a recliner of a vehicle seat so that the vehicle seat can be reclined. More specifically, the present invention relates to an overload protection device preventing abuse torque applied to the recliner handle from being transferred to the recliner of the vehicle seat. 
     2. Description of Related Art 
     Many vehicles today have vehicle seats with a seat back that is rotatably coupled to a seat cushion by a recliner. Typical recliners have a locked condition wherein the seat back is locked in a selected rotational position with respect to the seat cushion. Further, the typical recliners have an unlocked condition wherein the seat back can be reclined. One known recliner has a disc shaft projecting from the recliner. Rotating the disc shaft between a home angular position and a release angular position reconfigures the known recliner between the locked condition and the unlocked condition. 
     A recliner handle is typically operatively coupled to the disc shaft of the known recliner for rotating the disc shaft between the home angular position and the release angular position. Typically, the recliner handle has a home position that corresponds to the disc shaft being in the home angular position with the known recliner being in the locked condition. In addition, the recliner handle typically has a recline release position that corresponds to the disc shaft being in the release angular position with the known recliner being in the unlocked condition. When the recliner handle is in the home position, lifting upward on the recliner handle applies torque to the recliner handle. The upward torque applied to the recliner handle rotates the recliner handle and the connected disc shaft. When the recliner handle reaches the recline release position, the disc shaft is correspondingly rotated to the release angular position, and the known recliner is unlocked. 
     The known recliner includes a return spring biasing the recliner handle towards the home position to ensure the known recliner is placed in the locked condition when upward torque is not applied to the recliner handle. Thus, removal of upward torque on the recliner handle results in the recliner handle being rotated back to the home position which also rotates the disc shaft back to the home angular position and returns the known recliner to the locked condition. 
     However, the known recliner can be overloaded and potentially damaged when the recliner handle is in the home position and the recliner handle is pushed downward. In this case, downward torque applied to the recliner handle transfers excessive or abuse torque to the known recliner which can damage internal components within the known recliner. 
     Thus, it is desirable to prevent damage to the recliner when excessive downward pressure (abuse torque) is applied to the recliner handle when the recliner handle is in the home position. Further, it is desirable to transfer abuse torque applied to the recliner handle away from the recliner. Finally, it is desirable to include an overload protection device between the recliner handle and the recliner configured to avoid overloading the recliner when downward torque is applied to the recliner handle. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a recliner handle with an overload protection device for a vehicle seat having a recliner attached to a recliner B-bracket. The recliner handle is fixedly coupled to a handle spline having a disc shaft aperture configured to engage with a disc shaft operatively coupled to the recliner. A stop flange attached to the handle spline is configured to frictionally engage with an overload stop attached to the recliner B-bracket. The handle spline is rotatable in a first rotational direction between a first position wherein the stop flange is frictionally engaged with the overload stop and the disc shaft aperture is disengaged from the disc shaft and a second position wherein the disc shaft aperture engages the disc shaft. Rotation of the handle spline in a second rotational direction from the first position is restricted by the stop flange frictionally engaged with the overload stop. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
         FIG.  1    is a fragmentary perspective view of a vehicle seat having an overload protection device operatively coupled between a recliner and a recliner handle, according to one embodiment of the present invention; 
         FIG.  2    is an exploded view of the overload protection device of  FIG.  1   , showing the recliner, a recliner B-bracket having a cutout, a spring bracket, a clinch ring, a handle spline, and a handle inertia spring, according to one embodiment of the present invention; 
         FIG.  3    is a perspective view of the recliner of  FIG.  2   , illustrating a disc shaft projecting from the recliner; 
         FIGS.  4 A and  4 B  are perspective views of the spring bracket of  FIG.  2   ; 
         FIG.  5    is a perspective view of the clinch ring of  FIG.  2   ; 
         FIG.  6 A  is a partially transparent perspective view of the handle spline of  FIG.  2   , illustrating a disc shaft aperture within the handle spline; 
         FIG.  6 B  is a perspective view of the handle spline of  FIG.  6 A ; 
         FIG.  7    is an enlarged cutaway perspective view of the handle spline and the disc shaft taken along section line  7 - 7  of  FIG.  1   , showing the disc shaft aperture in the handle spline and the disc shaft in a neutral position with the disc shaft aperture disengaged from the disc shaft; 
         FIG.  8    is an enlarged cutaway perspective view of the handle spline and the disc shaft of  FIG.  7   , showing the handle spline rotated in a clockwise direction with respect to the disc shaft with the disc shaft aperture engaged with the disc shaft; 
         FIG.  9    is an enlarged cutaway perspective view of the handle spline and the disc shaft of  FIG.  7   , showing the handle spline rotated in a counterclockwise direction with respect to the disc shaft with the disc shaft aperture engaged with the disc shaft; 
         FIG.  10    is an exploded perspective view of the recliner of  FIG.  1   , illustrating assembly of the spring bracket and the handle spline with the disc shaft of the recliner; 
         FIG.  11    is a perspective view of the recliner of  FIG.  10    after assembly of the spring bracket and handle spline, illustrating insertion of the clinch ring into the handle spline; 
         FIG.  12    is a cross-sectional view of the recliner and the overload protection device taken along section line  12 - 12  of  FIG.  1   , illustrating the handle spline, the spring bracket, and the clinch ring assembled with the disc shaft; 
         FIG.  13    is a perspective view of the recliner and the overload protection device of  FIG.  11    after assembly of the clinch ring with the handle spline, illustrating assembly of the handle inertia spring with the spring bracket and the recliner B-bracket; 
         FIG.  14    is a perspective view of the recliner and overload protection device of  FIG.  13    in a home angular position with a stop flange of the spring bracket frictionally engaged with a cutout attached to the recliner B-bracket, illustrating the handle spline being rotated towards a recline release position; 
         FIG.  15    is an enlarged cutaway perspective view of the recliner and the overload protection device of  FIG.  14    in the home angular position, illustrating the handle spline being rotated towards the release angular position; 
         FIG.  16    is a perspective view of the recliner and the overload protection device of  FIG.  14    after the handle spline is rotated to the release angular position, illustrating the stop flange of the spring bracket being spaced apart from the cutout of the recliner B-bracket; 
         FIG.  17    is a perspective view of the recliner and the overload protection device of  FIG.  16    after the handle spline is rotated towards the home angular position, illustrating the stop flange of the spring bracket frictionally engaged with the cutout of the recliner B-bracket; 
         FIG.  18    is a cutaway view of the recliner and the overload protection device of  FIG.  17    in the home angular position, illustrating the handle spline and the disc shaft in the neutral position with the disc shaft aperture of the handle spline disengaged from the disc shaft; 
         FIG.  19    is a cutaway view of the recliner and the overload protection device of  FIG.  18    in the home angular position, illustrating abuse torque being applied to the handle spline while the disc shaft aperture is retained disengaged from the disc shaft; 
         FIG.  20    is a perspective view of the recliner and the overload protection device of  FIG.  19   , illustrating abuse torque applied the handle spline resulting in load being applied to the cutout of the recliner B-bracket; 
         FIG.  21    is a fragmentary perspective view of a vehicle seat having an overload protection device operatively coupled between a recliner and a recliner handle, according to a second embodiment of the present invention; 
         FIG.  22    is an exploded view of the overload protection device of  FIG.  21   , showing the recliner, a recliner B-bracket having a cutout with an overload stop, a handle spline with an integrated stop flange, and a handle inertia spring, according to a second embodiment of the present invention; 
         FIG.  23    is a cutaway perspective view of the overload protection device of  FIG.  22   , showing the integrated stop flange of the handle spline frictionally engaged with the overload stop on the recliner B-bracket cutout; 
         FIG.  24    is a partially transparent perspective view of the handle spline of  FIG.  23   , illustrating a disc shaft aperture passing through the handle spline; 
         FIG.  25    is a perspective view of the handle spline of  FIG.  24   , illustrating exterior surfaces of the handle spline; and 
         FIG.  26    is an enlarged cutaway perspective view of the handle spline and the disc shaft of  FIG.  23   , showing the disc shaft aperture in the handle spline and the disc shaft in a neutral position with the disc shaft aperture disengaged from the disc shaft. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       FIGS.  1  through  26    illustrate an overload protection device  10 ,  10 ′ connecting a recliner handle  14  to a recliner  18  of a vehicle seat  22  according to embodiments described herein. Directional references employed or shown in the description, figures or claims, such as top, bottom, upper, lower, upward, downward, lengthwise, widthwise, left, right, and the like, are relative terms employed for ease of description and are not intended to limit the scope of the invention in any respect. Referring to the Figures, like numerals indicate like or corresponding parts throughout the several views. 
       FIG.  1    shows a perspective view of a portion of the vehicle seat  22  having a seat back  26  rotatably connected to a seat cushion  30  by the recliner  18 , according to a first embodiment. The recliner handle  14  is fixedly coupled to the overload protection device  10  and rotatably coupled to the recliner  18 . As shown in  FIG.  1   , the recliner handle  14  is repositionable between a home position  14 A and a recline release position  14 B about an axis of rotation  34  of the recliner  18 . The home position  14 A of the recliner handle  14  corresponds to a home angular position  36 A of the recliner  18 . Further, the recline release position  14 B of the recliner handle  14  corresponds to a release angular position  36 B of the recliner  18 . 
     Applying upward torque on the recliner handle  14  and rotating the recliner handle  14  in a first rotational direction A (illustrated by arrow A shown in  FIG.  1   ) about the axis of rotation  34  of the recliner  18  from the home position  14 A towards the recline release position  14 B unlocks the recliner  18  such that the seat back  26  can be rotated with respect to the seat cushion  30 . In the embodiment shown in  FIG.  1   , the recliner handle  14  is rotated upward in a clockwise direction A with respect to the axis of rotation  34  of the recliner  18  to unlock the recliner  18 . 
     Referring to  FIG.  11   , a return spring  38  is operatively coupled between the recliner  18  and the recliner handle  14 . As shown in  FIG.  1   , the return spring  38  rotationally biases the recliner handle  14  towards the home position  14 A. When the recliner handle  14  is spaced apart from the home position  14 A, the return spring  38  automatically rotates the recliner handle  14  in a second rotational direction B (arrow B) towards the home position  14 A when the recliner handle  14  is released. The second rotational direction B is opposite the first rotational direction A. If the recliner handle  14  is rotated upward in the clockwise direction A to reposition the recliner handle  14  from the home position  14 A to the recline release position  14 B, then the recliner handle  14  is rotated downward in the counterclockwise direction B to reposition the recliner handle  14  from the recline release position  14 B back to the home position  14 A. 
     With certain recliners  18 , further rotation of the recliner handle  14  in the second rotational direction B past the home position  14 A (illustrated by arrow C shown in  FIG.  1   ) can overload the recliner  18  and cause damage to internal components of the recliner  18 . In addition, rotational motion of the recliner handle  14  in the direction of arrow C past the home position  14 A can overlock the recliner  18 . Overlocking the recliner  18  can potentially damage the recliner  18 . The overload protection device  10  prevents the recliner  18  from being overlocked when downward torque is applied to the recliner handle  14  when the recliner handle  14  is in the home position  14 A. More specifically, the overload protection device  10  restricts rotation of the recliner handle  14  past the home position  14 A in the second rotational direction C and diverts applied torque to the recliner handle  14  away from the recliner  18 . 
     An exploded view of the overload protection device  10  is shown in  FIG.  2   . Referring to  FIG.  2   , the recliner  18  includes a disc recliner assembly  42  having a guide plate  42 A rotatably coupled to a tooth plate  42 B. An exemplary disc recliner assembly  42  is an iDiSC 5 disc recliner assembly manufactured by Magna Seating Inc. As shown in  FIG.  1   , the guide plate  42 A of the disc recliner assembly  42  is fixedly coupled to a recliner B-bracket  44  with the recliner B-bracket  44  being fixedly coupled to the seat cushion  30 . The guide plate  42 A includes a plurality of bosses  46 ,  48  configured to matingly engage with respective notches  50 ,  52  in the recliner B-bracket  44 . It is understood that in alternate embodiments, attachment of the disc recliner assembly  42  to the recliner B-bracket  44  may include different means of fixedly coupling the guide plate  42 A to the recliner B-bracket  44  without varying the scope of the invention. 
     As best shown in  FIG.  10   , the tooth plate  42 B is fixedly coupled to the seat back  26 . Referring to  FIGS.  1  and  10   , when the tooth plate  42 B is unlocked with respect to the guide plate  42 A (by rotating the recliner handle  14  to the recline release position  14 B), the seat back  26  is rotatable with respect to the recliner B-bracket  44  and the attached seat cushion  30 . In certain embodiments, the recliner B-bracket  44  and the attached seat cushion  30  are also rotatable with respect to the seat back  26  when the guide plate and tooth plates  42 A,  42 B are unlocked relative to each other. 
     Referring to  FIGS.  1  and  10   , the tooth plate  42 B is locked to the guide plate  42 A when the recliner handle  14  is in the home position  14 A. Rotation of the tooth plate  42 B with respect to the guide plate  42 A is prevented while the recliner handle  14  is in the home position  14 A. Thus, rotation of the seat back  26  with respect to the seat cushion  30  is prevented when the recliner handle  14  is in the home position  14 A. 
     Referring to  FIG.  2   , a disc shaft  62  projects from the disc recliner assembly  42  with a longitudinal axis  34 A of the disc shaft  62  aligned with the axis of rotation  34  of the recliner  18 . The disc shaft  62  is formed of a metal, a plastic, and/or combinations thereof. Further, the disc shaft  62  is configured to lock and unlock the rotation of the tooth plate  42 B with respect to the guide plate  42 A based on the angular position  36 A,  36 B of the disc shaft  62 . Rotating the disc shaft  62  from the home angular position  36 A to the release angular position  36 B in first rotational direction A unlocks the guide plate  42 A and the tooth plate  42 B such that one of the guide plate  42 A and the tooth plate  42 B can be rotated with respect to the other one of the guide plate  42 A and the tooth plate  42 B. In other embodiments, both the guide plate  42 A and the tooth plate  42 B can be rotated about the axis of rotation  34  when the disc recliner assembly  42  is unlocked. Thus, in certain embodiments, the seat cushion  30  can be rotated towards and/or away from the seat back  26  as well as the seat back  26  being rotatable towards and/or away from the seat cushion  30 . 
     An enlarged view of the recliner  18  is shown in  FIG.  3   . Referring to  FIGS.  2  and  3   , the disc shaft  62  includes an elongated shaft end portion  66  extending along the longitudinal axis  34 A of the disc shaft  62 . The elongated shaft end portion  66  has a rounded rectangular shaped cross-section with opposing shaft flat side portions  72 ,  74 , shaft curved side portions  78 ,  78 ′ extending between the adjacent shaft flat side portions  72 ,  74 , and a distal end surface  80 . The distal end surface  80  of the elongated shaft end portion  66  of the disc shaft  62  is also shown in  FIGS.  7 ,  8 , and  9   . 
     As shown in  FIGS.  2  and  3   , the disc shaft  62  has a base portion  82  having a generally cylindrical cross-sectional shape with a plurality of flat sides  86 ,  90 ,  90 ′ and a base end face  94 . A cross-sectional view of a portion of the overload protection device  10  is shown in  FIG.  12    and illustrates additional details of the disc shaft  62 . Referring to  FIG.  12   , a central cylindrical portion  98  projects from the base end face  94  of the base portion  82  along the longitudinal axis  34 A of the disc shaft  62 . The central cylindrical portion  98  has an outer diameter  98 A that is less than a maximum diameter  82 A of the base portion  82 . Further, the central cylindrical portion  98  has a central end face  102  extending generally parallel to and spaced apart from the base end face  94  of the base portion  82 . A channel  106  extends circumferentially around an outer perimeter  98 ′ of the central cylindrical portion  98  spaced apart from both the central end face  102  and the base end face  94 . The channel  106  has an outer diameter  106 A that is less than the outer diameter  98 A of the central cylindrical portion  98 . The elongated shaft end portion  66  projects from the central end face  102  of the central cylindrical portion  98 . Further, the elongated shaft end portion  66  has a maximum diameter  66 A that is less than the outer diameter  98 A of the central cylindrical portion  98 . Also, the base portion  82 , the central cylindrical portion  98 , and the elongated shaft end portion  66  are aligned with the longitudinal axis  34 A of the disc shaft  62 . It will be appreciated that the size, shape, and length of the disc shaft  62  may vary without altering the scope of the invention. 
     Referring to  FIGS.  2 ,  3 , and  11   , the return spring  38  is a spiral torsional spring having a first spring end  38 A fixedly coupled to the base portion  82  of the disc shaft  62  and a second spring end  38 B fixedly coupled to a slot  142  in a boss  146  projecting from the guide plate  42 A. The first spring end  38 A of the return spring  38  is wrapped around the base portion  82  of the disc shaft  62  such that the first spring end  38 A frictionally engages with one or more of the flat sides  86 ,  90 ,  90 ′ of the base portion  82 . In certain embodiments, the return spring  38  is sized and shaped such that spring tension retains the first spring end  38 A in frictional engagement with the base portion  82  of the disc shaft  62  and retains the second spring end  38 B in an engaged position with the slot  142  in the boss  146  projecting from the guide plate  42 A. In alternate embodiments, one or both of the first and second spring ends  38 A,  38 B are fixedly coupled to the disc shaft  62  and the slot  142 , respectively, by a mechanical fastener, a welded connection, or the like. With the second spring end  38 B of the return spring  38  retained within the slot  142  in the boss  146  projecting from the guide plate  42 A, rotating the recliner handle  14  upward from the home position  14 A towards the recline release position  14 B rotates the disc shaft  62  from the home angular position  36 A to the release angular position  36 B and preloads the return spring  38 . When the recliner handle  14  is released, the spring torque in the return spring  38  urges the disc shaft  62  to rotate towards the home angular position  36 A. Returning the disc shaft  62  to the home angular position  36 A returns the recliner handle  14  to the home position  14 A and locks the disc recliner assembly  42 . It will be appreciated that the size and shape of the return spring  38  may vary without altering the scope of the invention. 
     As shown in  FIG.  2   , the overload protection device  10  includes the disc shaft  62  projecting from the recliner  18 , a spring bracket  158 , a clinch ring  162 , a handle spline  166 , a handle inertia spring  170 , and a tab  174  formed on the recliner B-bracket  44 . It will be appreciated that the overload protection device  10  may include additional components without varying the scope of the invention. 
     Referring to  FIGS.  2 ,  4 A, and  4 B , the spring bracket  158  has a generally flat main bracket portion  186  with opposing upper and lower bracket surfaces  190 ,  194  spaced apart by first and second bracket side walls  198 ,  202  defining a width of the spring bracket  158 . Extending from the main bracket portion  186  are a first flange  206 , a second flange  207 , and a stop flange  208 . The first flange  206  extends upward from a first end  210  of the main bracket portion  186  such that the first flange  206  and the upper bracket surface  190  of the main bracket portion  186  are generally perpendicular to one another and form an “L” shape. The first flange  206  has opposing inner and outer surfaces  206 A,  206 B and an elongated spring slot  214  extending between the opposing inner and outer surfaces  206 A,  206 B. The second flange  207  extends upward from a second end  222  of the main bracket portion  186 . The second flange  207  includes a flange base portion  226  adjacent the main bracket portion  186  and a distal flange end portion  230  that projects at an angle from the flange base portion  226 . The flange base portion  226  is generally parallel to the first flange  206  with the distal flange end portion  230  being generally parallel to the main bracket portion  186 . The stop flange  208  extends downward from the second bracket side wall  202  of the main bracket portion  186 . The stop flange  208  includes distal and proximal side walls  238 ,  242 . The proximal side wall  242  includes a stop surface  246 . 
     As shown in  FIGS.  2 ,  4 A, and  4 B , an alignment aperture  250  extends between the upper and lower bracket surfaces  190 ,  194  of the main bracket portion  186 . The alignment aperture  250  has a contoured inner profile  250 ′ with a plurality of splines  254  extending between the opposing upper and lower bracket surfaces  190 ,  194 . The plurality of splines  254  includes at least one narrow spline  254 A and at least one wide spline  254 B configured to matingly engage with at least one narrow spline  286 A and at least one wide spline  286 B located on the handle spline  166 . The wide spline  254 B of the alignment aperture  250  is an alignment feature for assembling the spring bracket  158  and the handle spline  166  with a predetermined relative orientation. Further, the alignment aperture  250  has a minimum opening diameter  250 A and a maximum opening diameter  250 B. The minimum opening diameter  250 A of the alignment aperture  250  is less than the maximum diameter  82 A of the base portion  82  of the disc shaft  62 , as shown in  FIG.  12   . The spring bracket  158  is assembled with the disc shaft  62  with the disc shaft  62  passing through the alignment aperture  250 . After assembly, the lower bracket surface  194  of the spring bracket  158  is supported by the base end face  94  of the base portion  82  of the disc shaft  62 . In addition, the spring bracket  158  is formed of a metal, a plastic, and/or combinations thereof. It will be appreciated that the size and shape of the spring bracket  158 , including the first and second flanges  206 ,  207 , the stop flange  208 , the spring slot  214 , and the alignment aperture  250  may vary without altering the scope of the invention. 
     As shown in  FIG.  5   , the clinch ring  162  is a generally ring-shaped disc with opposing top and bottom surfaces  162 A,  162 B, an outer side surface  162 C extending between the opposing top and bottom surfaces  162 A,  162 B, and a passageway  258  extending between the opposing top and bottom surfaces  162 A,  162 B forming a notch  258 ′ in the clinch ring  162 . The notch  258 ′ defining the passageway  258  includes a first lead-in surface  266 , a second lead-in surface  266 ′, and an inner cylindrical surface  262  extending between inner ends  266 A,  266 B of the adjacent first and second lead-in surfaces  266 ,  266 ′. The inner cylindrical surface  262  has a ring inner radius  262 A approximately equal to or greater than half of the outer diameter  106 A of the channel  106  in the central cylindrical portion  98  of the disc shaft  62 . The first and second lead-in surfaces  266 ,  266 ′ are configured to allow attachment of the clinch ring  162  to the disc shaft  62  within the channel  106  in the central cylindrical portion  98  of the disc shaft  62 . The clinch ring  162  is formed of a metal, a plastic, and/or combinations thereof. It will be appreciated that the size and shape of the clinch ring  162  may vary without altering the scope of the invention. 
     As shown in  FIGS.  2 ,  6 A, and  6 B , the handle spline  166  has a splined portion  270  having a generally cylindrical shape with an outer surface  274  extending between an upper end surface  278  and a lower end surface  282 . The outer surface  274  of the handle spline  166  has an outer profile  274 ′ sized and shaped to matingly engage with the inner profile  250 ′ of the alignment aperture  250  in the spring bracket  158 . Referring to  FIGS.  6 A and  6 B , the outer surface  274  of the handle spline  166  includes a plurality of splines  286  spaced around the outer profile  274 ′ of the splined portion  270  and extending along a longitudinal axis  34 B of the handle spline  166 . The longitudinal axis  34 B of the handle spline  166  is aligned with the axis of rotation  34  of recliner  18  and the longitudinal axis  34 A of the disc shaft  62  when the handle spline  166  is assembled with the disc shaft  62 , as illustrated in  FIG.  2   . 
     Referring to  FIGS.  4 A and  6 B , the plurality of splines  286  of the handle spline  166  includes at least one narrow spline  286 A and at least one wide spline  286 B configured to matingly engage with the at least one narrow spline  254 A and the at least one wide spline  254 B within the alignment aperture  250  of the spring bracket  158  when the handle spline  166  is assembled with the spring bracket  158 . The wide splines  254 B,  286 B of the alignment aperture  250  and the handle spline  166  are alignment features for assembling the spring bracket  158  and the handle spline  166  with a predetermined relative orientation. 
     The assembly of the handle spline  166  and the spring bracket  158  onto the disc shaft  62  is shown in  FIG.  10   .  FIG.  12    shows a cross-sectional view of the handle spline  166  assembled with the spring bracket  158  with the lower end surface  282  of the handle spline  166  inserted into the alignment aperture  250  in the spring bracket  158 . 
     As shown in  FIG.  6 A , the splined portion  270  of the handle spline  166  optionally includes a handle channel  288  extending around the outer periphery of the splined portion  270  and spaced apart from the upper end surface  278  of the splined portion  270 . The handle channel  288  is sized and shaped to matingly engage with and retain a snap feature on the recliner handle  14 . In other embodiments, the handle channel  288  is sized and shaped to receive a clip ring or similar fastening device to retain the recliner handle  14  in an engaged position with the handle spline  166 . In certain embodiments, the handle channel  288  is omitted from the handle spline  166  when an alternate method of attaching the recliner handle  14  to the handle spline  166  is selected. 
     Referring to  FIGS.  6 A and  6 B , the handle spline  166  includes a cylindrical ring  290  projecting from the splined portion  270 . The cylindrical ring  290  is generally cylindrically-shaped and has a longitudinal axis aligned with the handle spline  166  longitudinal axis  34 B. Further, the cylindrical ring  290  is spaced apart from the upper end surface  278  and the lower end surface  282  of the handle spline  166 . The handle channel  288  is also spaced apart from the cylindrical ring  290  and positioned between the cylindrical ring  290  and the upper end surface  278  of the handle spline  166 . The cylindrical ring  290  has an outer cylindrical surface  294  having an outer diameter  290 A greater than a maximum diameter  270 A of the splined portion  270 . Further, the cylindrical ring  290  includes opposing upper and lower surfaces  298 ,  298 ′ extending between respective upper and lower edges  294 A,  294 B of the outer cylindrical surface  294  and the outer surface  274  of the splined portion  270 . The lower surface  298 ′ of the cylindrical ring  290  is spaced apart from the lower end surface  282  of the handle spline  166  such that the lower surface  298 ′ of the cylindrical ring  290  frictionally engages with the upper bracket surface  190  of the spring bracket  158  when the lower end surface  282  of the handle spline  166  is inserted into the alignment aperture  250  of the spring bracket  158 , as shown in  FIG.  12   . 
     Referring to  FIGS.  6 A and  12   , the handle spline  166  includes an elongated disc shaft aperture  310  aligned with the longitudinal axis  34 B of the handle spline  166  with a lower opening  314  extending through the lower end surface  282  of the handle spline  166 . The disc shaft aperture  310  is sized and shaped to matingly engage with the disc shaft  62 . Thus, the disc shaft aperture  310  has an elongated inner aperture portion  310 A sized and shaped to matingly engage with the elongated shaft end portion  66  of the disc shaft  62  while maintaining about 6 degrees of loss motion between the disc shaft  62  and the disc shaft aperture  310 . It is understood that the amount of degrees of loss motion between the disc shaft  62  and the disc shaft aperture  310  can be greater or less than about 6 degrees without varying the scope of the invention. Further, the disc shaft aperture  310  has an elongated outer aperture portion  310 B sized and shaped to matingly engage with the central cylindrical portion  98  of the disc shaft  62 . In addition, the disc shaft aperture  310  has an upper end surface  310 C configured to frictionally engage with the distal end surface  80  of the disc shaft  62  when assembled as part of the overload protection device  10 . 
     Referring to  FIGS.  7  through  9   , there is about 6 degrees of lost motion between the handle spline  166  and the disc shaft  62  when the handle spline  166  is rotated.  FIG.  7    shows a cross-sectional view of the handle spline  166  and the disc shaft  62  taken along section line  7 - 7  of  FIG.  1    showing the disc shaft  62  and the handle spline  166  in a neutral position  322 . The neutral position  322  shown in  FIG.  7    corresponds to the disc shaft  62  being in the home angular position  36 A with the recliner handle  14  being unrestrained and aligned with the home position  14 A, as illustrated in  FIGS.  1  and  3   . As shown in  FIG.  7   , the elongated shaft end portion  66  of the disc shaft  62  has opposing shaft flat side portions  72 ,  74  and shaft curved side portions  78 ,  78 ′ extending between the opposing shaft flat side portions  72 ,  74 . 
     In contrast, as shown in  FIG.  7   , the cross-sectional shape of the inner aperture portion  310 A of the disc shaft aperture  310  in the handle spline  166  has a bowtie-shaped appearance, more generally described as an irregular concave hexagonal shape. The inner aperture portion  310 A includes opposing first and second side walls  324 ,  325  and opposing first and second end walls  326 ,  327 . The first side wall  324  comprises a first side portion  328  extending at an angle from a second side portion  328 ′ such that an interior angle  328 A between the first side portion  328  and the second side portion  328 ′ is greater than 180 degrees, as measured within the disc shaft aperture  310 . Similarly, the second side wall  325  includes a third side portion  329  extending at an angle from a fourth side portion  329 ′ such that an interior angle  329 A between the third side portion  329  and the fourth side portion  329 ′ is greater than 180 degrees, as measured within the disc shaft aperture  310 . Further, the first side portion  328  is generally parallel to and spaced apart from the fourth side portion  329 ′. Similarly, the second side portion  328 ′ is generally parallel to and spaced apart from the third side portion  329 . In addition, the first side portion  328  is non-parallel to the second side portion  328 ′. Likewise, the third side portion  329  is non-parallel to the fourth side portion  329 ′. In certain embodiments, one or more of the first, second, third, and fourth side portions  328 ,  328 ′,  329 ,  329 ′ include curved surfaces, tapered surfaces, and/or generally flat surfaces. 
     Also shown in  FIG.  7   , extending between ends  328 B,  329 B of the first side portion  328  and the third side portion  329  of the disc shaft aperture  310  is the first end wall  326 . Likewise, extending between ends  328 C,  329 C of the second side portion  328 ′ and the fourth side portion  329 ′ is the second end wall  327 . In the embodiment shown in  FIG.  7    the first and second end walls  326 ,  327  are curved walls. The inner aperture portion  310 A of the disc shaft aperture  310  is sized and shaped such that a first junction  331  of the first side portion  328  and the second side portion  328 ′ and a second junction  331 ′ of the third side portion  329  and the fourth side portion  329 ′ frictionally engage the respective adjacent shaft flat side portions  72 ,  74  of the disc shaft  62  when assembled. It is understood that in certain embodiments the first and second junctions  331 ,  331 ′ are spaced apart from the adjacent shaft flat side portions  72 ,  74  without altering the scope of the invention. When the disc shaft  62  is centered within the disc shaft aperture  310  in the neutral position  322  shown in  FIG.  7   , each of the first through fourth side portions  328 ,  328 ′,  329 ,  329 ′ of the disc shaft aperture  310  taper away from the adjacent shaft flat side portions  72 ,  74  of the disc shaft  62  with an approximate loss motion angle  332 ,  332 ′. Thus, each of the first through fourth side portions  328 ,  328 ′,  329 ,  329 ′ of the disc shaft aperture  310  are essentially disengaged from the adjacent shaft flat side portions  72 ,  74  of the disc shaft  62  when the handle spline  166  and the disc shaft  62  are in the neutral position  322  shown in  FIG.  7   . The approximate loss motion angle  332 ,  332 ′ represents the loss motion between the handle spline  166  and the disc shaft  62  when the handle spline  166  is rotated. 
     In order to engage the disc shaft aperture  310  of the handle spline  166  with the disc shaft  62 , the handle spline  166  is rotated through approximately the loss motion angle  332 ,  332 ′, as illustrated in  FIGS.  8  and  9   . Once the disc shaft aperture  310  has fully engaged with the disc shaft  62 , additional rotation of the handle spline  166  results in the disc shaft  62  rotating with the handle spline  166 . 
     When the recliner handle  14  is in the home position  14 A shown in  FIG.  1   , the handle spline  166  and the disc shaft  62  are in the neutral position  322  with the second side portion  328 ′ of the disc shaft aperture  310  disengaged from the adjacent shaft flat side portion  72  of the disc shaft  62 , as shown in  FIG.  7   . More specifically, the second side portion  328 ′ of the disc shaft aperture  310  tapers away from the adjacent shaft flat side portion  72  of the disc shaft  62  by the loss motion angle  332  when the handle spline  166  and the disc shaft  62  are in the neutral position  322 . 
     Upward torque applied to the recliner handle  14  rotates the recliner handle  14  and the attached handle spline  166  in the clockwise direction A illustrated in  FIG.  1   . The clockwise rotation A of the recliner handle  14  rotates the handle spline  166  in a clockwise direction  333  shown in  FIG.  8   . Initial rotation of the handle spline  166  less than the loss motion angle  332  does not result in rotation of the disc shaft  62  because the disc shaft aperture  310  is disengaged from the disc shaft  62 . Thus, applying torque in the clockwise direction A to the recliner handle  14  and rotating the recliner handle  14  less than the loss motion angle  332  results in the handle spline  166  rotating independent of the disc shaft  62  since the disc shaft  62  is disengaged from the disc shaft aperture  310 . The disc shaft  62  engages with the disc shaft aperture  310  when the recliner handle  14  and the attached handle spline  166  rotate approximately the loss motion angle  332  in the clockwise direction  333 . The disc shaft  62  rotates with the handle spline  166  after the recliner handle  14  and the handle spline  166  rotate more than the loss motion angle  332 . 
     The disc shaft  62  is engaged with the disc shaft aperture  310 , as illustrated in  FIG.  8   , when the recliner handle  14  is spaced apart from the home position  14 A by at least the loss motion angle  332 . Referring to  FIG.  8   , as the handle spline  166  is rotated in the clockwise direction  333  from the neutral position  322  shown in  FIG.  7   , the second side portion  328 ′ of the disc shaft aperture  310  is pivoted towards the adjacent shaft flat side portion  72  of disc shaft  62 . The second side portion  328 ′ of the disc shaft aperture  310  frictionally engages with the adjacent shaft flat side portion  72  of the disc shaft  62  when the handle spline  166  is rotated through the loss motion angle  332  in the clockwise direction  333 . The third side portion  329  of the disc shaft aperture  310  likewise frictionally engages with the adjacent shaft flat side portion  74  when the handle spline  166  is rotated in the clockwise direction  333  since the third side portion  329  and the second side portion  328 ′ of the disc shaft aperture  310  are generally parallel. Additional rotation of the handle spline  166  in the clockwise direction  333  causes the disc shaft  62  to rotate with the handle spline  166  since the second and third side portions  328 ′,  329  of the disc shaft aperture  310  have engaged with the adjacent shaft flat side portions  72 ,  74  of the disc shaft  62 . Thus, the loss motion angle  332  illustrates the amount of loss motion between the handle spline  166  and the disc shaft  62  when the handle spline  166  is rotated in the clockwise direction  333  from the neutral position  322 . 
     As shown in  FIG.  7   , the fourth side portion  329 ′ of the disc shaft aperture  310  tapers away from the adjacent shaft flat side portion  74  of the disc shaft  62  by the loss motion angle  332 ′ when the handle spline  166  and the disc shaft  62  are in the neutral position  322 . When the handle spline  166  is rotated in a counterclockwise direction  333 ′ from the neutral position  322  of  FIG.  7   , the fourth side portion  329 ′ is pivoted towards the adjacent shaft flat side portion  74  of disc shaft  62 , as illustrated in  FIG.  9   . The fourth side portion  329 ′ frictionally engages with the adjacent shaft flat side portion  74  of the disc shaft  62  when the handle spline  166  is rotated through the loss motion angle  332 ′ in the counterclockwise direction  333 ′. The first side portion  328  of the disc shaft aperture  310  likewise frictionally engages with the adjacent shaft flat side portion  72  when the handle spline  166  is rotated in the counterclockwise direction  333 ′ since the fourth side portion  329 ′ and the first side portion  328  of the disc shaft aperture  310  are generally parallel. Additional rotation of the handle spline  166  in the counterclockwise direction  333 ′ causes the disc shaft  62  to rotate with the handle spline  166  since the first and fourth side portions  328 ,  329 ′ of the disc shaft aperture  310  have engaged with the adjacent shaft flat side portions  72 ,  74  of the disc shaft  62 . Thus, the loss motion angle  332 ′ illustrates the amount of loss motion between the handle spline  166  and the disc shaft  62  when the handle spline  166  is rotated in the counterclockwise direction  333 ′ from the neutral position  322 . In certain embodiments, the loss motion angle  332  is approximately equal to the loss motion angle  332 ′. However, it will be appreciated that the loss motion angle  332  can be greater than or less than loss motion angle  332 ′ without varying the scope of the invention. Further, the clockwise direction  333  and the counterclockwise direction  333 ′ of the handle spline  166 , as viewed in  FIGS.  8  and  9   , is generically described as first and second rotational directions  333 ,  333 ′, respectively. 
     The handle spline  166  has a clinch ring slot  334  extending radially through part of the cylindrical ring  290 , as shown in  FIGS.  6 A and  12   . The clinch ring slot  334  is configured to allow insertion of the clinch ring  162  into the clinch ring slot  334 . Further, the clinch ring slot  334  is sized and shaped such that the clinch ring  162  is aligned with the channel  106  in the disc shaft  62  when the spring bracket  158  and the handle spline  166  are assembled on the disc shaft  62 , as shown in  FIG.  12   . The clinch ring  162 , the clinch ring slot  334 , and the channel  106  in the disc shaft  62  are sized and shaped such that insertion of the clinch ring  162  into the clinch ring slot  334  does not restrict the rotational movement of the handle spline  166  with respect to the disc shaft  62 . In particular, the clinch ring  162  does not restrict the rotation of the handle spline  166  with respect to the disc shaft  62  while the handle spline  166  is rotated in the first and second rotational directions  333 ,  333 ′ through at least an angle equal or greater than the loss motion angle  332 ,  332 ′ from the neutral position  322  shown in  FIG.  7   . It will be appreciated that the size and shape of the clinch ring slot  334 , the channel  106  in the disc shaft  62 , and the clinch ring  162  may vary without altering the scope of the invention. 
     As shown in  FIG.  6 A , the clinch ring slot  334  includes opposing upper and lower surfaces  334 A,  334 B as well as opposing side surfaces  334 C,  334 D. The disc shaft aperture  310  forms an upper opening  338  in the upper surface  334 A of the clinch ring slot  334 . A lower opening  338 ′ is formed by the disc shaft aperture  310  in the lower surface  334 B of the clinch ring slot  334 . 
     Referring to  FIG.  2   , the handle inertia spring  170  is a coil spring having a coiled portion  346  having a central passageway  348 , a first spring end  350  extending from an upper side  346 A of the handle inertia spring  170 , and a second spring end  350 ′ extending from a lower side  346 B of the handle inertial spring  170 . The handle inertia spring  170  is formed of a metal. 
     In the embodiment shown in  FIG.  2   , the first spring end  350  of the handle inertia spring  170  is bent into an “L” shape having a first retention portion  354  extending at an angle from the handle inertia spring  170 . The first spring end  350  and the first retention portion  354  are sized and shaped such that the first spring end  350  can be passed through the spring slot  214  in the spring bracket  158 . The first retention portion  354  retains the first spring end  350  in frictional engagement with the spring bracket  158  when the handle inertia spring  170  is assembled as part of the overload protection device  10 , as illustrated in  FIG.  14   . 
     Also shown in  FIG.  2   , the second spring end  350 ′ of the handle inertia spring  170  includes a bent portion  358  generally extending in the direction of the axis of rotation  34  of the recliner  18  after assembly with the spring bracket  158  and the recliner B-bracket  44 . A second retention portion  358 ′ extends at an angle from the bent portion  358  of the handle inertia spring  170 . As shown in  FIG.  14   , the second retention portion  358 ′ and the bent portion  358  of the handle inertia spring  170  are sized and shaped such that the second spring end  350 ′ can be passed through a spring retention hole  366  in the recliner B-bracket  44  when the handle inertia spring  170  is assembled as part of the overload protection device  10 . More specifically, the second spring end  350 ′ is configured to pass through the spring retention hole  366  in the recliner B-bracket  44  when the handle spline  166  and the second flange  207  of the spring bracket  158  are passed through the central passageway  348  of the coiled portion  346 , as illustrated in  FIG.  13   . Further, the second retention portion  358 ′ and the bent portion  358  are sized and shaped such that the second retention portion  358 ′ retains the second spring end  350 ′ through the spring retention hole  366  after the second spring end  350 ′ is inserted through the spring retention hole  366  in the recliner B-bracket  44 . It will be appreciated that the size and shape of the handle inertia spring  170 , including the first and second spring ends  350 ,  350 ′, may vary without altering the scope of the invention. 
     The tab  174  formed on the recliner B-bracket  44  is shown in  FIGS.  2  and  14   . Referring to  FIG.  2   , the recliner B-bracket  44  includes a mounting portion  44 A configured to matingly engage with bosses  46 ,  48  projecting from the guide plate  42 A of the disc recliner assembly  42 . In various embodiments, the mounting portion  44 A is integrally formed with the recliner B-bracket  44 . In alternate embodiments, the mounting portion  44 A is a separate component assembled with the recliner B-bracket  44 . Referring to  FIG.  14   , the recliner B-bracket  44  and the mounting portion  44 A can be formed out of a metal, a plastic, and/or combinations thereof. Preferably, at least the mounting portion  44 A of the recliner B-bracket  44  is formed from a metal. In certain embodiments, the mounting portion  44 A is a metal bracket that is fixedly coupled to the recliner B-bracket  44 . 
     Referring to  FIGS.  2  and  14   , the tab  174  formed on the recliner B-bracket  44  is bent away from a disc-shaped portion  44 B of the mounting portion  44 A of the recliner B-bracket  44 . In alternate embodiments, the tab  174  is a separate component fixedly coupled to the mounting portion  44 A and/or to the recliner B-bracket  44 . The tab  174  includes an overload stop  174 A formed by an edge surface of the tab  174 . The overload stop  174 A is offset from the disc-shaped portion  44 B of the mounting portion  44 A. The tab  174  is sized and shaped such that the stop surface  246  of the stop flange  208  of the spring bracket  158  will frictionally engage the overload stop  174 A of the tab  174  when the spring bracket  158  and handle spline  166  are assembled on the disc shaft  62  and the spring bracket  158  rotated towards the tab  174  in the second rotational direction B shown in  FIG.  14   . It will be appreciated that the size and shape of the recliner B-bracket  44 , the mounting portion  44 A, the tab  174 , and the overload stop  174 A may vary without altering the scope of the invention. 
       FIGS.  10  through  13    illustrate an installation process of the overload protection device  10  onto the recliner  18 . Referring to  FIG.  10   , the recliner  18  is shown assembled with the recliner B-bracket  44  and the seat back  26 . The recliner  18  includes the disc recliner assembly  42  comprising the guide plate  42 A, the tooth plate  42 B, and the disc shaft  62  as well as other components. Further, the return spring  38  is shown assembled with the disc recliner assembly  42  in  FIG.  10   . The lower end surface  282  of the handle spline  166  is inserted into the alignment aperture  250  in the spring bracket  158  with the plurality of splines  286  of the handle spline  166  aligned with the plurality of splines  254  in the alignment aperture  250 , as illustrated by arrow D shown in  FIG.  10   . The handle spline  166  is assembled with the disc shaft  62  after the handle spline  166  is assembled with the spring bracket  158 , as illustrated by arrow E shown in  FIG.  10   . Alternatively, the spring bracket  158  can be assembled with the disc shaft  62  prior to the handle spline  166  being inserted into the alignment aperture  250  of the spring bracket  158 . In both cases, a portion of the disc shaft  62  passes through the alignment aperture  250  of the spring bracket  158 . 
       FIG.  11    shows the handle spline  166  and the spring bracket  158  assembled on the disc shaft  62  of the disc recliner assembly  42 . The clinch ring  162  is inserted into the clinch ring slot  334  in the handle spline  166 , as illustrated by arrow F shown in  FIG.  11   . The clinch ring  162  axially retains the handle spline  166  on the disc shaft  62 . 
     A cross-sectional view of the assembly of the disc shaft  62 , the spring bracket  158 , the handle spline  166 , and the clinch ring  162  is shown in  FIG.  12   . Referring to  FIG.  12   , the lower bracket surface  194  of the spring bracket  158  abuts the base end face  94  of the disc shaft  62 . In addition, the lower end surface  282  of the handle spline  166  either abuts the base end face  94  of the disc shaft  62  or the lower end surface  282  is spaced apart from the base end face  94  of the disc shaft  62 , depending on specific dimensions of the individual components. Further, the lower end surface  282  of the handle spline  166  is positioned within the alignment aperture  250  in the spring bracket  158 . The spring bracket  158  will rotate with the handle spline  166  since the plurality of splines  254  in the alignment aperture  250  are matingly engaged with the plurality of splines  286  of the handle spline  166 . 
     While the spring bracket  158  and the handle spline  166  are shown assembled with the disc shaft  62  in  FIG.  12   , the handle spline  166  is not fixedly coupled to the disc shaft  62 . The handle spline  166  is selectively coupled to the disc shaft  62  based in part on the rotational position of the handle spline  166  with respect to the disc shaft  62 . As shown in  FIGS.  7  through  9   , there is about 6 degrees of lost motion between the handle spline  166  and the disc shaft  62  (illustrated by the loss motion angles  332 ,  332 ′) when the handle spline  166  is rotated from the neutral position  322 . It is understood that the magnitude of the loss motion angles  332 ,  332 ′ can vary without altering the scope of the invention. 
     Also shown in  FIG.  12   , the lower surface  298 ′ of the cylindrical ring  290  of the handle spline  166  abuts the upper bracket surface  190  of the spring bracket  158 . The clinch ring slot  334  in the handle spline  166  is aligned with the channel  106  of the disc shaft  62  such that the clinch ring  162  can be inserted into the clinch ring slot  334 . Preferably, a portion of the inner cylindrical surface  262  of the clinch ring  162  is positioned within the channel  106 , preventing movement of the handle spline  166  in the direction of the axis of rotation  34 . 
     After the spring bracket  158  and the handle spline  166  are assembled with the disc shaft  62 , the handle inertia spring  170  is attached to the spring bracket  158  and the recliner B-bracket  44  as illustrated in  FIG.  13   . Referring to  FIG.  13   , a first portion  346 ′ of the coiled portion  346  of the handle inertia spring  170  is positioned underneath the distal flange end portion  230  of the second flange  207  of the spring bracket  158  such that the upper surface  346 A of the coiled portion  346  abuts the distal flange end portion  230  of the spring bracket  158 . A second portion  346 ″ of the coiled portion  346  of the handle inertia spring  170  is placed on the spring bracket  158  such that the lower side  346 B of the coiled portion  346  abuts the upper bracket surface  190  of the main bracket portion  186  of the spring bracket  158  with the handle spline  166  positioned in the central passageway  348  of the handle inertia spring  170 . The first spring end  350  of the handle inertia spring  170  is slid through the spring slot  214  in the first flange  206  of the spring bracket  158 . The second spring end  350 ′ of the handle inertia spring  170  is passed through the spring retention hole  366  in the recliner B-bracket  44 . The spring torque of the handle inertia spring  170  retains the first retention portion  354  of the first spring end  350  of the handle inertia spring  170  in frictional engagement with the first flange  206  of the spring bracket  158 . In addition, the spring torque of the handle inertia spring  170  retains the second retention portion  358 ′ of the second spring end  350 ′ of the handle inertia spring  170  in frictional engagement with the recliner B-bracket  44 . 
     Referring to  FIG.  14   , the spring torque within the handle inertia spring  170  rotationally biases the spring bracket  158  and handle spline  166  towards the home angular position  36 A in the second rotational direction B. The stop surface  246  on the spring bracket  158  is frictionally engaged with the overload stop  174 A on the recliner B-bracket  44  when the handle spline  166  is in the home angular position  36 A. More specifically, the return spring  38  which is operatively coupled between the recliner  18  and the disc shaft  62  biases the disc shaft  62  towards the home angular position  36 A. As such, the return spring  38  automatically rotates the disc shaft  62  towards the home angular position  36 A when the disc shaft  62  is unloaded by an externally-applied load. Further, the handle inertia spring  170  rotationally biases the spring bracket  158  towards the home angular position  36 A. When the stop surface  246  on the spring bracket  158  frictionally engages with the overload stop  174 A on the recliner B-bracket  44 , and the disc shaft  62  is in the home angular position  36 A, the disc shaft aperture  310  of the handle spline  166  is automatically positioned in the neutral position  322  with the disc shaft  62  disengaged from the disc shaft aperture  310 . 
       FIG.  15    shows a cutaway view of the disc shaft  62  and the handle spline  166  of  FIG.  14    illustrating the spring bracket  158  and the handle spline  166  in the home angular position  36 A with the disc shaft  62  disengaged from the disc shaft aperture  310  of the handle spline  166 . The home angular position  36 A shown in  FIG.  15    corresponds to the neutral position  322  of the disc shaft  62  and the handle spline  166  shown in  FIG.  7   . Referring to  FIG.  15   , when the handle spline  166  is unloaded (i.e., an externally-applied load is not applied to the recliner handle  14  attached to the handle spline  166 ), the spring torque in the handle inertia spring  170  ensures that the spring bracket  158  and the coupled handle spline  166  are in the home angular position  36 A. If the handle spline  166  is spaced apart from the home angular position  36 A and the recliner handle  14  is unrestrained, the handle inertial spring  170  automatically rotates the spring bracket  158  in the second rotational direction B until the stop surface  246  of the stop flange  208  frictionally engages the overload stop  174 A of the recliner B-bracket  44 . 
     Referring to  FIGS.  14  and  15   , the return spring  38  of the recliner  18  rotationally biases the disc shaft  62  towards the home angular position  36 A in the second rotational direction B when the disc shaft  62  is unloaded. The return spring  38  ensures that the recliner  18  is placed in the locked condition when upward torque is not applied to the recliner handle  14 . When the recliner  18  includes a cam that locks and unlocks the recliner  18 , rotating the disc shaft  62  in the first rotational direction A is alternatively described as a cam unlocking direction A. Similarly, rotating the disc shaft  62  in the second rotational direction B is alternatively described as a cam locking direction B. 
     During normal use, upward torque (first rotational direction A) is applied to the recliner handle  14  to initiate normal recline operation of the vehicle seat  22 , as shown in  FIG.  1   . Rotation of the recliner handle  14  in the first rotational direction A applies torque to the handle spline  166  causing the handle spline  166  to be rotated in a clockwise direction (arrow G), as viewed in  FIGS.  14  and  15   . As illustrated in  FIGS.  7  and  8   , there is lost motion present between the handle spline  166  and the disc shaft  62  of about 6 degrees. It will be understood that the loss motion between the handle spline  166  and the disc shaft  62  can be greater or less than about 6 degrees without varying the scope of the invention. Referring to  FIGS.  7 ,  8 , and  15   , the handle spline  166  rotates in the clockwise direction (arrow  333  in  FIG.  8   , arrow Gin  FIG.  15   ) through approximately the loss motion angle  332  before the second and third side portions  328 ′,  329  of the disc shaft aperture  310  frictionally engage the respective shaft flat side portions  72 ,  74  of the disc shaft  62 . This initial rotation of the handle spline  166  takes up the looseness between the disc shaft aperture  310  and the disc shaft  62 . The disc recliner assembly  42  functions as a typical direct drive disc recliner assembly after looseness between the disc shaft aperture  310  and the disc shaft  62  is taken up by the initial rotation of the handle spline  166 . 
     Additional rotation of the handle spline  166  in the clockwise direction (arrow  333  in  FIG.  8   , arrow Gin  FIG.  15   ) past the loss motion angle  332  causes the disc shaft  62  to rotate with the handle spline  166 . Rotation of the recliner handle  14  in the first rotational direction A shown in  FIG.  1    results in the handle spline  166 , the spring bracket  158 , and the disc shaft  62  being rotated to the release angular position  36 B shown in  FIG.  16   . When the recliner handle  14  is rotated in the first rotational direction A, rotational torque (arrow G in  FIG.  16   ) is applied to the handle spline  166 , retaining the handle spline  166  in the release angular position  36 B. In certain embodiments, the handle spline  166  is rotated past the release angular position  36 B when the recliner handle  14  is rotated further in the first rotational direction A. 
     When the handle spline  166  is in the release angular position  36 B shown in  FIG.  16   , releasing the recliner handle  14  results in the handle inertia spring  170  automatically rotating the spring bracket  158  in the counterclockwise direction (arrow H) towards the home angular position  36 A, as shown in  FIG.  17   . The handle spline  166  rotates with the spring bracket  158  since the plurality of splines  286  of the handle spline  166  are matingly engaged with the plurality of splines  254  in the alignment aperture  250  of the spring bracket  158 . Spring torque in the handle inertia spring  170  retains the stop surface  246  on the spring bracket  158  in frictional engagement with the overload stop  174 A of the recliner B-bracket  44 . 
       FIGS.  18  through  20    illustrate operation of the overload protection device  10  during abnormal use. Referring to  FIG.  1   , abnormal use occurs when a load is applied to the recliner handle  14  in the abuse rotation direction C when the recliner handle  14  is in the home position  14 A. The handle spline  166  and the disc shaft  62  are shown in the home angular position  36 A in  FIG.  18    with the disc shaft  62  disengaged from the disc shaft aperture  310 . The relative rotational positions of the handle spline  166  and the disc shaft  62  shown in  FIG.  18    is alternatively described as the neutral position  322 . 
     The relative rotational positions of the handle spline  166  and the disc shaft  62  in the neutral position  322  shown in  FIG.  18    correspond to the recliner handle  14  being in the home position  14 A shown in  FIG.  1   . The relative rotational position of the disc shaft aperture  310  with respect to the disc shaft  62  of  FIG.  18    also corresponds to the relative rotational position of the disc shaft aperture  310  with respect to the disc shaft  62  shown in  FIG.  7   . In specific, when the handle spline  166  and the disc shaft  62  are in the neutral position  322  shown in  FIGS.  7  and  18   , the fourth side portion  329 ′ of the disc shaft aperture  310  in the handle spline  166  tapers away from the adjacent shaft flat side portion  74  of the disc shaft  62 . As such, the disc shaft aperture  310  is disengaged from the disc shaft  62  when the handle spline  166  is in neutral position  322  with no load applied to the recliner handle  14 . 
     Referring to  FIGS.  1  and  19   , when the recliner handle  14  is in the home position  14 A shown in  FIG.  1    and a load is applied to the recliner handle  14  in the abuse rotation direction C, abuse torque J ( FIG.  19   ) is applied to the handle spline  166 . The abuse torque J applied to the handle spline  166  in the cam locking direction B is represented by arrow J shown in  FIG.  19   . An exemplary amount of abuse torque J is approximately 120 Nm applied to the recliner handle  14  in a cam locking direction B when the recliner handle  14  is in the home position  14 A. 
     Referring to  FIG.  19   , the abuse torque J applied to the handle spline  166  urges the handle spline  166  to rotate past the home angular position  36 A in the abuse rotation direction C. For typical disc recliners lacking the overload protection device  10 , the abuse torque J applied to the handle spline  166  causes the handle spline  166  to rotate in the abuse rotation direction C past the home angular position  36 A and causes the typical disc recliner to be overlocked. However, as shown in  FIG.  19   , the stop surface  246  on the spring bracket  158  of the overload protection device  10  is frictionally engaged with the overload stop  174 A on the recliner B-bracket  44  when the handle spline  166  is in the neutral position  322 . Further, the handle spline  166  is matingly engaged with the spring bracket  158  and rotationally travels with the spring bracket  158 . More specifically, the plurality of splines  286  of the handle spline  166  are matingly engaged with the plurality of splines  254  in the alignment aperture  250  of the spring bracket  158  such that the handle spline  166  rotates with the spring bracket  158 , as illustrated in  FIGS.  10  and  12   . Thus, abuse torque J applied to the handle spline  166  initiates rotation of the handle spline  166  in the abuse rotation direction C, causing the stop surface  246  on the stop flange  208  of the spring bracket  158  to impact the overload stop  174 A on the tab  174  of the recliner B-bracket  44 , as shown in  FIG.  19   . The engagement between the stop flange  208  and the overload stop  174 A prevents rotation of the handle spline  166  in the abuse rotation direction C past the home angular position  36 A. Referring to  FIG.  20   , the abuse torque J applied to the handle spline  166  is transferred to the spring bracket  158  and applies load K (illustrated by arrow K) to the overload stop  174 A on the tab  174  of the recliner B-bracket  44 . This effectively transfers the abuse torque J applied to the handle spline  166  to the tab  174  of the recliner B-bracket  44 . 
     As shown in  FIGS.  7 ,  9  and  20   , the looseness between the disc shaft  62  and the disc shaft aperture  310  in the handle spline  166  prevents the abuse torque J from being transferred to the disc shaft  62 .  FIG.  7    shows the handle spline  166  and the disc shaft  62  in the neutral position  322  with the first side portion  328  and the fourth side portion  329 ′ of the disc shaft aperture  310  tapering away from the adjacent shaft flat side portions  72 ,  74 .  FIG.  9    shows the handle spline  166  rotated in the counterclockwise direction  333 ′ from the neutral position  322  shown in  FIG.  7    through approximately the loss motion angle  332 ′ with the overload stop  174 A omitted from the recliner B-bracket  44 . The abuse rotation direction C in  FIG.  20    corresponds to counterclockwise direction  333 ′ shown in  FIG.  9   . Referring to  FIG.  9   , the handle spline  166  would have to rotate in the counterclockwise direction  333 ′ (abuse rotation direction C of  FIG.  20   ) through approximately the loss motion angle  332 ′ prior to the fourth side portion  329 ′ of the disc shaft aperture  310  frictionally engaging the adjacent shaft flat side portion  74  of the disc shaft  62 . The disc shaft  62  rotates with the handle spline  166  when the handle spline  166  rotates past the loss motion angle  332 ′ in the counterclockwise direction  333 ′ since the first and fourth side portions  328 ,  329 ′ have frictionally engaged the respective adjacent shaft flat side portions  72 ,  74 . 
     However, as shown in  FIG.  20   , frictional engagement between the stop surface  246  on the stop flange  208  of the spring bracket  158  and the overload stop  174 A on the tab  174  of the recliner B-bracket  44  prevents rotation of the handle spline  166  in the abuse rotation direction C past the home angular position  36 A. The abuse torque J applied to the recliner handle  14  is transferred through the handle spline  166  and loads up the spring bracket  158  against the tab  174  of the recliner B-bracket  44 . The looseness between the disc shaft aperture  310  in the handle spline  166  and the disc shaft  62  prevents transferring the abuse torque J from the handle spline  166  to the disc shaft  62 . Since the abuse torque J is transferred to the recliner B-bracket  44  instead of being transferred to the disc shaft  62 , the disc shaft  62  is not rotated past the home angular position  36 A when downward torque is applied to the recliner handle  14 . The overload protection device  10  prevents the disc shaft  62  from being rotated in the abuse rotation direction C past the home angular position  36 A, effectively preventing the recliner  18  from being overlocked. Further, internal components of the disc recliner assembly  42  are not directly loaded by downward torque of the recliner handle  14  since load applied by the abuse torque J is transferred between the recliner handle  14 , the handle spline  166 , the spring bracket  158 , and the tab  174  of the recliner B-bracket  44 . 
     A second embodiment of a recliner handle  14  with an overload protection device  10 ′ is illustrated in  FIGS.  21  through  26   . The first embodiment of the overload protection device  10  illustrated in  FIG.  2    includes a spring bracket  158  having a stop flange  208  that is assembled with a separate handle spline  166 . In contrast, the overload protection device  10 ′ shown in  FIGS.  21  through  26    has a stop flange  208 ′ integrated with the handle spline  166 ′. In addition, the handle inertia spring  170  shown in  FIG.  2    is replaced with a handle inertia spring  170 ′ that is operatively connected between the handle spline  166 ′ and the recliner B-bracket  44 , as shown in  FIG.  21   . 
       FIG.  22    shows an exploded view of components of the second embodiment of the overload protection device  10 ′. The handle spline  166 ′ includes a disc shaft aperture  310 ′ passing longitudinally through the handle spline  166 ′. The handle spline  166 ′ is assembled with the recliner  18  by inserting the disc shaft  62  of the recliner  18  into the disc shaft aperture  310 ′. The handle inertia spring  170 ′ of the second embodiment includes a first spring end  350 A configured to frictionally engage with a first spring retention surface  370  on handle spline  166 ′. Further, a second spring end  350 B of the handle inertia spring  170 ′ is configured to frictionally engage with a spring retention flange  366 B on the recliner B-bracket  44 , as shown in  FIG.  21   . 
       FIG.  23    shows the handle spline  166 ′ assembled with the recliner B-bracket  44  and the disc shaft  62  of the second embodiment, illustrating the integrated stop flange  208 ′ of the handle spline  166 ′ frictionally engaged with the overload stop  174 A of the recliner B-bracket  44 . A comparison of the first embodiment shown in  FIG.  15    and the second embodiment shown in  FIG.  23    illustrates similarities between the first and second embodiments. For example, the stop flange  208  of the spring bracket  158  rotates with the handle spline  166  when the handle spline  166  is rotated, as shown and described with respect to  FIGS.  15  through  17   . Referring to  FIG.  23   , the stop flange  208 ′ of the second embodiment rotates with the handle spline  166 ′ since the stop flange  208 ′ is integrally formed with the handle spline  166 ′. 
     In addition, the disc shaft aperture  310 ′ of the handle spline  166 ′ of the second embodiment is shaped and sized similarly to the disc shaft aperture  310  of the handle spline  166  in the first embodiment, as shown by comparing  FIG.  24    and  FIG.  7   . Referring to  FIG.  24   , the disc shaft aperture  310 ′ of the handle spline  166 ′ of the second embodiment has an inner aperture portion  310 A′ sized and shaped to matingly engage with the elongated shaft end portion  66  of the disc shaft  62  while maintaining about 6 degrees of loss motion between the disc shaft  62  and the disc shaft aperture  310 ′. It is understood that the amount of degrees of loss motion between the disc shaft  62  and the disc shaft aperture  310 ′ can be greater or less than about 6 degrees without varying the scope of the invention. The inner aperture portion  310 A′ of the disc shaft aperture  310 ′ includes opposing first and second side walls  324 ′,  325 ′ and opposing first and second end walls  326 ′,  327 ′. The first side wall  324 ′ comprises a first side portion  328 D extending at an angle from a second side portion  328 D′ such that an interior angle  328 A′ between the first side portion  328 D and the second side portion  328 D′ is greater than 180 degrees, as measured within the disc shaft aperture  310 ′. Similarly, the second side wall  325 ′ includes a third side portion  329 D extending at an angle from a fourth side portion  329 D′ such that an interior angle  329 A′ between the third side portion  329 D and the fourth side portion  329 D′ is greater than 180 degrees, as measured within the disc shaft aperture  310 ′. Further, the first side portion  328 D is generally parallel to and spaced apart from the fourth side portion  329 D′. Similarly, the second side portion  328 D′ is generally parallel to and spaced apart from the third side portion  329 D. In addition, the first side portion  328 D is non-parallel to the second side portion  328 D′. Likewise, the third side portion  329 D is non-parallel to the fourth side portion  329 D′. In certain embodiments, one or more of the first, second, third, and fourth side portions  328 D,  328 D′,  329 D,  329 D′ include curved surfaces, tapered surfaces, and/or generally flat surfaces. Also shown in  FIG.  24   , extending between ends  328 B′,  329 B′ of the first side portion  328 D and the third side portion  329 D of the disc shaft aperture  310 ′ is the first end wall  326 ′. Likewise, extending between ends  328 C′,  329 C′ of the second side portion  328 D′ and the fourth side portion  329 D′ is the second end wall  327 ′. In the embodiment shown in  FIG.  24    the first and second end walls  326 ′,  327 ′ are curved walls. 
       FIG.  26    shows a cutaway perspective view of the handle spline  166 ′ of the second embodiment assembled with the disc shaft  62 . In  FIG.  26   , the disc shaft  62  and the disc shaft aperture  310 ′ in the handle spline  166 ′ are positioned in a neutral position  322  with the disc shaft aperture  310 ′ disengaged from the disc shaft  62 . Further, the inner aperture portion  310 A′ of the disc shaft aperture  310 ′ is sized and shaped such that a first junction  331 D of the first side portion  328 D and the second side portion  328 D′ and a second junction  331 D′ of the third side portion  329 D and the fourth side portion  329 D′ frictionally engage the respective adjacent shaft flat side portions  72 ,  74  of the disc shaft  62  when assembled, as shown in  FIG.  26   . It is understood that in certain embodiments the first and second junctions  331 D,  331 D′ are spaced apart from the adjacent shaft flat side portions  72 ,  74  of the disc shaft  62  without varying the scope of the invention. When the disc shaft  62  is centered within the disc shaft aperture  310 ′ in the neutral position  322  shown in  FIG.  26   , each of the first through fourth side portions  328 D,  328 D′,  329 D,  329 D′ of the disc shaft aperture  310 ′ taper away from the adjacent shaft flat side portions  72 ,  74  of the disc shaft  62  with an approximate loss motion angle  332 ,  332 ′. Thus, each of the first through fourth side portions  328 D,  328 D′,  329 D,  329 D′ of the disc shaft aperture  310 ′ are essentially disengaged from the adjacent shaft flat side portions  72 ,  74  of the disc shaft  62  when the handle spline  166 ′ and disc shaft  62  are in the neutral position  322  shown in  FIG.  26   . The approximate loss motion angle  332 ,  332 ′ represents the loss motion between the handle spline  166 ′ and the disc shaft  62  when the handle spline  166 ′ is rotated. As with the first embodiment, rotating the handle spline  166 ′ from the neutral position  322  less than the loss motion angle  332  results in the handle spline  166 ′ rotating independently of the disc shaft  62 . The disc shaft aperture  310 ′ engages with the disc shaft  62  when the handle spline  166 ′ rotates approximately the loss motion angle  332  from the neutral position  322  shown in  FIG.  26   . The disc shaft  62  rotates with the handle spline  166 ′ as long as the disc shaft aperture  310 ′ is engaged with the disc shaft  62 . 
     Referring to  FIG.  25   , the handle spline  166 ′ has a plurality of splines  286 ′ spaced around an outer perimeter  274 A of a splined portion  270 ′ configured to matingly engage with the recliner handle  14 . Further, the disc shaft aperture  310 ′ extends axially through the handle spline  166 ′. Also shown in  FIG.  25   , the handle spline  166 ′ includes a spring retention flange  370 A having a first spring retention surface  370  configured to frictionally engage and retain the first spring end  350 A of the handle inertia spring  170 ′. As shown in  FIG.  24   , the spring retention flange  370 A extends circumferentially partially around the handle spline  166 ′. In the embodiment shown in  FIG.  24   , the spring retention flange  370 A extends between the stop flange  208 ′ and the first spring retention surface  370 . It is understood that the stop flange  208 ′ and the first spring retention surface  370  can vary in size, shape, position, and location, including being separated on the handle spline  166 ′ without varying the scope of the invention. 
     The handle spline  166 ′ shown in  FIGS.  24  and  25    is sized and shaped to be formed out of a plastic material using a molding process. An exemplary suitable plastic material is Nylon 6/6 with about 30% glass fill. Alternatively, the handle spline  166 ′ is formable out of a metal such as a zinc aluminum alloy and similar metals. An exemplary, suitable zinc aluminum alloy is Zamak 5 (aluminum 4%, copper 1%, and zinc 95%). It is understood that the handle spline  166 ′ can be formed of alternate metals and molded from alternate plastic materials without varying the scope of the invention. 
     One benefit of the recliner handle  14  with the overload protection device  10 ,  10 ′ is damage to the recliner  18  is prevented when downward torque (abuse torque) is applied to the recliner handle  14  when the recliner handle  14  is in the home position  14 A. A second benefit is the abuse torque applied to the recliner handle  14  is transferred away from the recliner  18 . A third benefit of the overload protection device  10 ,  10 ′ between the recliner handle  14  and the recliner  18  is overloading the recliner  18  is avoided when downward torque is applied to the recliner handle  14 . 
     The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described.