Abstract:
The disclosed system employs vehicle seat track assembly including an easy entry system for a vehicle seat, further including a memory system having an adjustment increment compensator which allows for memory system which records displacement by an incremental distance, y, to be employed in a vehicle seat which employees a seat track that allows for fore-aft adjustment by a second incremental distance, x, thereby allowing seat designers and manufacturers to employ a single easy entry memory system on multiple vehicle seat track designs, each of which may have seat tracks which allow fore-aft adjustment at different increments, without modifying the easy entry memory system for each variation in fore-aft adjustment increment. The disclosed compensator also insures that the memory system will be activated even when there is a slight misalignment of the memory module components at the time of activation.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is the U.S. national phase of PCT Application No. PCT/US2012/031448 filed on Mar. 30, 2012, published as WO 2013/147846, the disclosure of which is incorporated in its entirety by reference herein. 
     BACKGROUND 
     Vehicles such as passenger cars typically include seats for the use of the driver and other occupants. In many vehicles, the position of the seats may be adjusted for the comfort of the occupants. Adjustment options, particularly for the first row of seats, typically include the capability to move the seat in fore and aft directions by operation of a track assembly which mounts the seat to the vehicle floor. These existing systems typically employ a comfort adjustment bar which is operatively connected to the seat track locking system to release the track locking system to unlock the seat from the lower track when the bar is operated by the occupant, thereby allowing the occupant to slidably position the seat along the length of the tracks as desired. The seat track fore-aft adjustment system may be designed to incrementally adjust the seat forward and rearward by any desired increment. One such adjustable seat track assembly is disclosed in PCT Publication No. WO 2010/080597 A1. 
     Some vehicle seats, particularly first row seats, may include the capability of folding the seatback forward then sliding the entire seat forward to facilitate access to the second row of seats. This is known as an “easy entry” option, and is commonly seen in two-door vehicles. The easy entry option allows the generally upright back portion of the seat to be dumped, or pivoted, forward from its normal position, at the same time unlocking the seat to allow the seat to be slidably positioned forward in the passenger compartment to provide more spaced behind the seat to gain entrance into the second row of seats. 
     Seats which include an easy entry capability may also include a memory system, typically disposed in one of the pair of seat tracks and configured to remember a longitudinal position of the corresponding upper track with respect to the corresponding lower track such that, whenever the seatback is dumped forward and the seat slid forward for easy entry to the second row, and the seat is thereafter slidably positioned rearward for use by the front row occupant, the sliding seat automatically stops at the previously selected use position. Vehicle seats including easy entry capabilities with position memory systems are disclosed in PCT Publication No. WO 2010/080593 A1. 
     In memory systems of the type disclosed in PCT Publication No. WO 2010/080593 A1, a separate set of notches in one of the pairs of upper or lower tracks are often employed and accessed by a memory wheel to “record” the amount of seat travel to accomplish the above-described memory function. 
     SUMMARY 
     The disclosed system employs an easy entry memory system for a vehicle seat which employees a seat track that allows for fore-aft adjustment by a first incremental distance, x. The memory system includes an adjustment increment compensator which allows for the memory system, which records seat fore-aft displacement by a second incremental distance, y, to be employed in the vehicle seat, thereby allowing seat designers and manufacturers to employ a single easy entry memory system on multiple vehicle seat designs, each of which may have seat tracks which allow fore-aft adjustment at different increments, without modifying the easy entry memory system for each variation in fore-aft adjustment increment. The disclosed compensator also insures that the memory system will be activated even when there is a slight misalignment of the memory module components at the time of activation. 
     The disclosed system includes a vehicle seat memory track assembly including two pairs of upper and lower seat rails that are positioned on opposite sides of a seat bottom of a vehicle seat. Each lower rail is fixedly attachable to a vehicle support structure, such as a vehicle floor, and each upper rail is fixedly attachable to the seat bottom and slidably mounted in a respective lower seat rail. The disclosed system further includes a seat track locking system including two track locking assemblies, each one disposed in one of the pairs of tracks, and each track locking assembly being configured to lock a respective upper rail in a variety of longitudinal positions with respect to its corresponding lower rail, wherein the longitudinal positions are spaced apart be a first predetermined adjustment increment, such as, for example, five millimeters. A first actuator is operably connected to the seat track locking system. The first actuator includes a release lever positioned to be moved by an occupant from a non-activated position to an activated position, whereby the activation bracket disengages the seat track locking system to allow slidable longitudinal movement of the seat to a different desired seating position. 
     The disclosed system also includes a second actuator for activating the memory system under certain pre-defined conditions, such as when the seatback is folded forward and the seat is slidably positioned forward to allow an occupant to gain entry to the second row of seats. The memory system is mounted on one of the upper rails and is engageable with the corresponding lower rail whenever the memory system is activated. When activated, the memory system records the longitudinal travel of the seat in a second predetermined adjustment increment, such as, for example, 10 millimeters, so that after entry to the second row is gained and the operator slides the seat rearward along the lower rails, the memory system stops the seat at approximately the same use position that the seat was in prior to folding and moving the seat for easy entry. 
     In the disclosed system, however, the first adjustment increment of the seat track is smaller than the second adjustment increment recordable by the memory system. The second actuator therefore includes a compensator which activates the memory system even in the event the condition for activation is delayed until such time as the track has been slidably positioned to a position that can be tracked by the memory system to a distance that is a whole number multiple of the second adjustment increment. The compensator of the disclosed system is also effective to insure that the memory system is activated even when there is a slight misalignment of the memory module components at the time of desired activation of the memory system. 
     In one disclosed embodiment, the compensator includes an activation disc which is rotated to urge an activation sled to, in turn activate the memory module. In the event that the module cannot engage (because it records at a different increment than the positional increment of the seat track, or because it is misaligned), the disc rotates relative to the sled and provides a stored activation force upon the sled, resulting in delayed activation of the memory module as the seat is further slidably positioned. 
     In a second disclosed embodiment, the compensator includes an outer sled and an inner sled, each of which are slidably positioned by an activation lever to urge the inner sled to, in turn, activate the memory module. In the event that the module cannot engage (because it records at a different increment than the positional increment of the seat track, or because it is misaligned), the outer sled moves linearly relative to the inner sled and provides a stored activation force upon the inner sled, resulting in delayed movement of the inner sled and activation of the memory module as the seat is further slidably positioned. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a rear perspective view of a bucket seat; 
         FIG. 2  is a rear perspective view of one embodiment of the disclosed vehicle seat memory track assembly; 
         FIG. 3  is a partial perspective view of a portion of the seat track assembly of  FIG. 2 , showing the track lock activation member; 
         FIG. 4  is a perspective view of the disclosed memory module; 
         FIG. 5  is a lower view (when installed) of the memory module; 
         FIG. 6  is an isolated view of the memory module gear wheel, end stop, spindle, and memory nut; 
         FIG. 7  is a side forward elevational view of the track assembly (on the memory system side) from the opposite side of the track shown in  FIG. 2 ; 
         FIG. 8  is a partial rearward side perspective view of portion of the track assembly shown in  FIG. 7  (on the memory side) including the memory system in the non-activated condition with the cover removed from the activation disc; 
         FIG. 9  is a partial side elevational view of a portion of the track assembly (on the memory side) including the memory system in the non-activated condition with the cover removed from the activation disc; 
         FIG. 10  is a side elevational view, in partial cross-section, of the track assembly (on the memory side, but from the opposite side of the track shown in  FIG. 9 ) showing the memory module in the non-activated position; 
         FIG. 11  is a partial side elevational view of a portion of the track assembly (on the memory side) including the memory system in the activated, but intermediate condition with the cover removed from the activation disc; 
         FIG. 12  is a side elevational view, in partial cross-section, of the track assembly (on the memory side, but from the opposite side of the track shown in  FIG. 11 ) showing the memory module in the intermediate position; 
         FIG. 13  is a partial side elevational view of a portion of the track assembly (on the memory side) including the memory system in the activated condition with the cover removed from the activation disc; 
         FIG. 14  is a side elevational view, in partial cross-section, of the track assembly (on the memory side, but from the opposite side of the track shown in  FIG. 13 ) showing the memory module in the activated position; 
         FIG. 15  is a rearward perspective, partial phantom view of the additional support bracket, the sled, and the reset lever with the reset lever in the disengaged position; 
         FIG. 16  is a rearward perspective, partial phantom view of the additional support bracket, the sled, and the reset lever with the reset lever in the engaged position; 
         FIG. 17  is a partial rearward side perspective view of a portion of the track assembly shown in  FIG. 7  (on the memory side) including the memory system with the cover removed from the activation disc, as the backrest is raised from a dumped forward to a use position; 
         FIG. 18  is a partial rearward side perspective view of portion of the track assembly shown in  FIG. 7  (on the memory side) including the memory system with the cover removed from the activation disc and with the activation disc rotated to the non-activated condition; 
         FIG. 19  is a partial forward side perspective view, in partial cross-section, of a portion of a second embodiment of a track assembly (on the memory side) including a memory system incorporating a second embodiment of the compensator with the activation lever in the activated position; 
         FIG. 20  is a side cross-sectional view of the track assembly of  FIG. 19  (on the memory system side) showing the memory module in the intermediate position; 
         FIG. 21  is a side cross-sectional view of the track assembly of  FIG. 19  (on the memory system side) showing the lower sled and memory module in the activated position; 
         FIG. 22  is a partial forward side elevational view of the track assembly of  FIG. 19  (on the memory system side) showing the sled assembly in the inactive position; 
         FIG. 23  is a side cross-sectional view of the track assembly of  FIG. 19  (on the memory system side, but from the opposite side of the track shown in  FIG. 23 ) showing the sled assembly and memory module each in the inactive position; 
         FIG. 24  is a partial side view of the track assembly of  FIG. 19  (on the memory system side) showing the upper and lower sleds each in the active position with the reset lever engaged; and 
         FIG. 25  is a side cross-sectional view of the track assembly of  FIG. 19  (on the memory system side, but from the opposite side of the track shown in  FIG. 24 ) showing the upper sled in the inactive position, and the lower sled and memory module each in the active position. 
     
    
    
     DETAILED DESCRIPTION 
     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 teachings of the present invention. 
     Referring to  FIG. 1 , the disclosed vehicle seat memory track assembly may be used with a vehicle seat, such as bucket seat  10 , or other similar type seat commonly installed as the front row of seats in a vehicle. The bucket seat  10  includes a seat portion  12  and a backrest  14 . Each of the seat portion  12  and the backrest  14  may be cushioned and upholstered with a suitable fabric, vinyl, or leather cover for aesthetics and the comfort of the seat occupants. The backrest  14  may be attached for pivotal rotation relative to the seat portion  12  to provide a variety of inclination positions for the seated occupant. The backrest  14  may also be rotatable between an inclined, use position and a collapsed (or dumped) position, folded forward over the seat portion  12  to provide more space within the vehicle for ingress, egress, or stowage. The pivotal movement of the backrest  14  relative to the seat portion  12  may be accomplished by actuating one of one or more handles  16  which are operably connected to a backrest adjustment mechanism (not shown) to adjust the inclination of, and/or dump, the backrest  14 . 
     Referring now to  FIGS. 1 and 2 , the seat track memory system may include at least one pair of upper and lower rails. In the illustrated embodiment, the seat track memory system includes two pairs of upper and lower rails,  18 ,  20  and  22 ,  24 , arranged in a spaced-apart, generally parallel configuration on opposite sides of the seat bottom  12 . Each lower rail  20 ,  24  is fixedly attached to a vehicle support structure, such as a vehicle floor. Each upper rail  18 ,  22  is fixedly attached to the seat bottom  12  and slidably mounted in a respective lower seat rail  20 ,  24  for movement of the upper rails  18  and  22  and, thus, the seat, relative to the floor of the vehicle. 
     Referring now to  FIGS. 2 and 3 , the disclosed system includes a seat track locking system including at least one locking assembly  26  (shown in  FIG. 3 ) connected to one of the pair of upper and lower rails and operable to lock the upper rail  18  from movement with respect to the lower rail  20  when the locking assembly  26  is engaged. The disclosed system employs a pair of locking assemblies (each as shown as  26  in  FIG. 3 ), one each mounted, respectively, on upper rails  18  and  22 . Each locking assembly  26  is operable to move from a disengaged condition during which each of the upper rails  18 ,  22  may be slidably positioned within lower rails  20 ,  24 , and an engaged position during which each of the upper rails  18 ,  22  is locked in one of a plurality of selectable longitudinal locations with respect to lower rails  20 ,  24 . Further details relating to the structure and operation of similar seat track locking systems are disclosed in PCT Publication No. WO 2010/080597 A1, the disclosure of which is hereby incorporated herein by reference. In one embodiment, the longitudinal positioning locations are spaced five millimeters (5 mm) apart from each other. 
     A first actuator is operably connected to the seat track locking system, and is movable between a non-activated position and an activated position whereby the seat track locking system is disengaged to allow slidable longitudinal (i.e., fore-aft) movement of the seat. In the disclosed system, the first actuator includes a release lever  28 , which may include a handle or other handgrip (not shown) attached at the outboard end (i.e., the end nearest the forward edge of the seat bottom  12 ). The release lever  28  is attached at its inboard end to a crossbar (or tube)  30  that is rotatably connected at each end, respectively, to support brackets  32 ,  34 , which support brackets  32 ,  34  are fixedly secured (such as, for example, by welding) to their corresponding upper rails  18 ,  22 . The release lever  28  is fixedly connected to the crossbar  30  such that upward lifting of the lever handle  28  rotates crossbar  30 . In an alternative embodiment, the release lever  28  can be configured as a conventional towel bar-type actuator mounted to extend within the upper and lower rail pars, as shown in PCT Publication No. WO 2010/080597 A1. 
     In the illustrated embodiment, as shown in  FIG. 2 , the first actuator also includes an activation bracket  36 ,  38  associated with each pair of upper and lower rails. Each activation bracket  36 ,  38  is fixedly mounted on the end of the crossbar  30  adjacent and exterior to its associated pair of upper and lower rails for rotation from a first position (shown, for example, in  FIGS. 2 and 7 ) to a second position (as shown, for example, in  FIGS. 11-14 ), at which second position each activation bracket  36 ,  38  presses an activation button,  40 ,  42  which is connected to each track locking assembly  26  associated with each pair of upper and lower rails, and which, when depressed, causes each track locking assembly  26  to disengage, allowing rails  18 ,  22  to be slidably positioned with respect to rails  20 ,  24 . 
     Referring now to  FIG. 2 , the disclosed system includes a memory system, generally indicated as  50 , mounted on one of the pairs of upper and lower rails  22 ,  24  which, when engaged, disengages the seat track locking system, and records the last user-selected seating position of the vehicle seat to allow for forward movement of the seat from the user selected location to a more forward location (such as, for example, when the backrest  14  is dumped to allow ingress or egress to or from, respectively, a rearward seat), and thereafter return the seat rearward up to, but not past, the recorded user-selected location. 
     Referring now to  FIG. 10 , the memory system  50  includes a memory module  52  disposed in one of the pairs of tracks  22 ,  24 . When activated, the memory module  52  is configured to record the travel of the upper track  22  with respect to the lower track  24 , thereby remembering a longitudinal position of the corresponding upper track with respect to the lower track. The memory module  52  is pivotally connected to a pivot bracket  54 , which is fixed to the first upper track  22 . The memory module  52  is pivotable from a raised, non-activated position (shown in  FIG. 10 ) to either (1) a fully lowered, activated position (shown in  FIG. 14 ), or (2) to a partially lowered, intermediate position (shown in  FIG. 12 ). 
     Referring now to  FIGS. 4-6 , the memory module  52  includes a track wheel assembly  56  including a track gear wheel  58  rotatably mounted on a wheel support bracket  60 . The wheel support bracket  60  is pivotally mounted on the pivot bracket  54 , which in turn is mounted on the upper track  22 . The track gear wheel  58  is rotatably engageable with the first lower track  24  (see  FIG. 14 ) when the memory module  52  is moved to the fully activated position. The track gear wheel  58  includes a plurality of gear teeth  62  that are configured to extend into notches  64  formed in the first lower track  24  as the track gear wheel  58  moves with respect to the first lower track  24 . The track gear wheel  58  is also connected to a threaded spindle  66  that receives a threaded memory nut  68 . The memory nut  68  has an end stop (not shown) that engages an end stop of the track gear wheel  58  when the memory module is in the memorized position (for example, when the seat has been again moved rearward to its selected use position after the backrest has been dumped and the seat moved forward for ingress or egress to or from the second row seats). The memory module  52  may also include a clock spring (not shown) having one end engaged with the track gear wheel  58  and an opposite end engaged with a plastic disc that is fixed with respect to the wheel support bracket  60  on which the track gear wheel  58  is mounted, such that the clock spring urges the track gear wheel  58  toward an initial position into engagement with the memory nut  68 . The memory module  52  may also include a spring  55  that biases the memory module  52  toward the raised, non-activated position. 
     If a particular gear tooth  62  is not aligned with the respective notch  64  in the first lower track when the memory module  52  is urged downward toward the fully activated position, the memory module  52  will be temporarily held in an intermediate position, as shown in  FIG. 12  and further described herein. In one embodiment, the notches  64  are spaced ten millimeters (10 mm) apart from each other, allowing the module to “remember” and restore the seat to within ten millimeters (10 mm) of its original position. 
     Referring now to  FIGS. 7 and 8 , the disclosed memory system  50  also includes an additional support bracket  70  fixed to the upper track  18 , and a sled  72 , mounted for slidable movement on additional support bracket  70  which support bracket  70  is fixedly secured to upper rail  22 , either directly, or indirectly by securing bracket  70  to bracket  34 . 
     Memory system  50  also includes a second actuator including a compensator  74 , an activation lever  76 , and a Bowden cable  84 . In the embodiment illustrated in  FIGS. 2-18 , and with reference particularly to  FIG. 8 , the compensator  74  includes an activation disc  78  which, along with the activation lever  76 , is pivotally mounted on the additional support bracket  70 . A spring  80  is disposed between the activation disc  78  and the activation lever  76  for biasing the activation lever  76  forwardly (i.e., in the clockwise direction as shown in  FIG. 8 ) with respect to the activation disc  78 . A pre-tensioning spring  82  is also disposed between the additional support bracket and the activation disc  78  for biasing the activation disc  78  rearward (i.e., in the counter-clockwise direction as shown in  FIG. 8 ) to pretension the Bowden cable  84  connected to the activation disc  78  and the seatback  14 . 
     The activation lever  76  extends across a portion of the top surface of the upper rail  22  and the sled  72 . The sled  72  is biased rearwardly, toward a non-activated position, by a sled spring  86 , when the memory system  50  is deactivated. The Bowden cable  84  connects the activation disc  78  to the backrest  14  such that, when the backrest  14  is dumped forward, the Bowden cable  84  is refracted, thereby rotating the activation disc  78  forwardly (i.e., in the clockwise direction as shown in  FIG. 8 ), which, in turn compresses spring  80 , thereby applying a forward rotational (i.e., in the clockwise direction as shown in  FIG. 8 ) force upon activation lever  76 . As illustrated in  FIGS. 9-14 , when actuated by the refracting Bowden cable  84  and the rotating activation disc  78 , activation lever  76  moves into contact with the facing surface  88  of the sled  72 , thereby urging the sled in a forward direction. A cam surface  90  located on the underside of sled  72 , contacts a tab  92  on the wheel support bracket  60  as the sled is moved forward, thereby urging the memory module  52  downward into its activated position. 
     It should be noted that, although the disclosed embodiment of  FIGS. 2-18  employs the Bowden cable  84  and sled  72  in an orientation in which the cable retracts, and the sled moves, in a forward direction to activate the memory system  50 , it is contemplated that the disclosed orientation of these components may be altered or reversed to facilitate these motions in the rearward direction to activate the memory system  50 , such as, for example, in the second disclosed embodiment of  FIGS. 19-25 . Also, components which are described in this disclosure as moving “downward” or “upward” in their operation, may alternatively be oriented such that they perform the described functions through motions in the direction opposite from the directions disclosed in the specific embodiments described herein. 
     Referring to  FIGS. 9-14 , when the seatback  14  is dumped forward and the Bowden cable  84  rotates activation disc  78 , and thereby the activation lever  76  to urge sled  72  towards the memory activation position, the activation disc  78  also moves the reset activation lever  94  downwardly with respect to the activation bracket  38  until the reset activation lever  94  engages a stop on the activation bracket  38 . The activation disc  78  then moves the reset activation lever  94  together with the activation bracket  38  downward, thereby depressing seat lock release button  42 , thereby releasing the seat track lock system. Thus, when the seatback  14  is dumped forward the rotation of activation disc  78  simultaneously urges the sled  72  of the memory system towards its activated position, while causing disengagement of the seat track locking system  26 , thereby allowing for slidable movement of the dumped seat. 
     As further described herein, the disclosed compensator mechanism  74  allows the memory module  52  to function when mounted in a seat track system wherein the fore-aft seat adjustment increments are less than memory module increments (such as, for example, the five millimeter fore-aft adjustment increment and ten millimeter memory module increment of the disclosed embodiment), or when there is a slight misalignment between the locking system and the memory module. It will thus be appreciated that this disclosed memory system  50  allows for production of a single, standard memory system (such as, for example, the disclosed ten millimeter increment memory system), and implementation of that memory system with seat track systems having varying fore-aft increments (such as, for example, the five millimeter seat track system disclosed herein) in addition to matching the memory system with a ten millimeter seat track system. 
     Under normal non-memory operation (i.e., when the memory module  52  is de-activated) the track gear wheel  58  is disengaged from the first lower track  24 , and the position of the first upper track  22  a may be fixed with respect to the first lower track  24  by the track locking system. When the memory module  52  is activated by pivoting the seat back  14  of the vehicle seat forward, each of the track locking assemblies  26  are move from a locked (or engaged) position to a released (or disengaged) position. At the same time, the memory module  52  is urged downward into the activated position as shown in  FIGS. 13 and 14 , or to an intermediate, biased-downward-but-not-yet-engaging position as shown in  FIGS. 11 and 12 , in the event the lowermost tooth  62  of the wheel is not aligned with a notch  64  in the lower track due to misalignment or different four-aft positioner and memory module incremental distances as described above. 
     Referring now to  FIGS. 15-18 , in the disclosed system of  FIGS. 1-18 , the memory module activation system includes a reset lever  96 , which is movably mounted on the sled  72  and engageable with the additional support bracket  70 . As shown in  FIGS. 15 and 18 , when the sled  72  is in the de-activated position (i.e., when it is biased rearward by the spring member  86 ), the rearward end  100  (the end inboard of the sled) of the reset lever  96  is retained in a raised, non-interference position with respect to a cutout  98  in the additional support bracket  70 . As will be explained in further detail below, when the sled is moved into the activated position (i.e., when it is forced forward by the activation lever  76  as the activation lever  76  is pivoted forward due to the rotation of the activation disc  78  due to retraction of the Bowden cable), the rearward end  100  of reset lever  96  is urged downward by the resilient spring element  102  into a cutout  98  on the additional support bracket  70 , thereby locking the sled in the forward, activated position shown in  FIGS. 16 and 17 . Thus, once locked, the reset lever  96  remains biased downwardly in the locked position by spring  102 . 
     Referring to  FIGS. 9 and 10 , as previously described, the reset activation lever  94  is pivotally mounted on the activation bracket and is configured to actuate the reset lever  96  and thereby move the reset lever from the locked position to the unlocked position, as explained below in detail. The reset activation lever  94  is biased upwardly, toward a non-activated position by a bias spring  104  that extends between the activation bracket  38  and the reset activation lever  94 . 
     Operation of the memory system  50  will now be described in greater detail.  FIGS. 9 and 10  show the memory system  50  in the deactivated condition, such as when the backrest is upright and the seat is locked in a preferred use position on the track assembly. The sled  72  is similarly biased by spring member  86  in the de-activated position, and the reset lever  96  in its raised, inactive position. In this normal use condition, memory module  52  is pivoted upward into its non-activated position by virtue of biasing spring  55 , whereby track gear wheel  58  is disengaged from the lower track  24  (as shown in  FIG. 10 ). 
     To activate the memory system  50 , the seatback  14  is pivoted forwardly (or dumped) causing the Bowden cable which interconnects a location on the frame of the backrest to the activation disc to rotate the activation disc, causing the activation disc to rotate from the non-activated position (shown in  FIGS. 8-10 ) to an activated position (shown in  FIGS. 11-14 ). As a result, the activation lever  76  is urged forwardly toward its activated position by the activation disc  78  and compensator spring  50 . The activation lever  76 , in turn, engages the sled  72  and slides the sled forwardly along the additional support bracket  70  and against the bias of the sled spring  86  to its activated position. The sled in turn engages a projection  92  (shown in  FIG. 4 ) formed on the memory module, and urges the memory module downward toward its activated position. 
     As mentioned above, if a respective gear tooth  62  on the gear wheel of the memory module is not aligned with a respective notch  64  in the first lower track when the memory module is moved towards its activated position, the memory module will be temporarily held in the intermediate positions shown in  FIGS. 11 and 12 . In such case, the activation lever  76  and sled  72  will not move fully forward to their respective activated positions. Instead, the compensator spring is configured to allow relative movement of the activation disc  78  with respect to activation lever  76 , yet maintain sufficient spring force upon the lever  76  (and, therefore, the sled  72 ) such that the activation disc may move all away to its activated position while the activation lever  76 , sled  72 , and thus, the memory module  52  are each held in an intermediate position. 
     When the vehicle seat bottom (and upper tracks) are then moved forward slightly such that a respective gear tooth  62  on the gear wheel  58  becomes aligned with a notch  64  in the lower track, the memory module  52  will be able to pivot further downwardly to the activated position, due to urging by the activation lever  76  and sled  72 , such that the track gear wheel engages into one or more notches in the first lower track, as shown in  FIG. 14 . Continued forward movement of the seat bottom and upper tracks will then cause the gear wheel to rotate along the first lower track, which causes the memory nut to move along the spindle and away from the gear wheel as previously described. 
     Referring to  FIG. 13 , as the activation disc  78  moves toward its activated position, the activation disc  78  also moves the reset activation lever  94  downwardly with respect to the activation bracket  38  until the reset activation lever engages a stop on the activation bracket. The activation disc then moves the reset activation lever together with the activation bracket downward. Because the reset activation lever  94  is moved first with respect to the activation bracket  38 , the reset activation lever  94  does not engage the reset lever  96  when the reset activation lever and activation bracket are moved downwardly together. Furthermore, referring to  FIG. 2 , because the activation bracket  38  on the memory side is linked with the activation bracket  36  on the non-memory side, rotation of the activation bracket  38  on the memory side causes the activation bracket  36  on the non-memory side to rotate as well. As a result, each activation bracket engages a track locking system activation member  42  (shown in  FIG. 14  for the memory side), and moves the activation member downwardly to unlock the corresponding seat track locking system. 
       FIGS. 13 and 14  illustrate the memory system  50  in the activated position. In this position, the rearward end of the reset lever  96  moves downward into the notch  98  in the additional support bracket  70  (as shown in  FIG. 16 ) and engages the bracket such that the sled  72  is retained in its forward, activated position. When the vehicle seat bottom and upper tracks  18 ,  22  are then moved forward, the engaged track gear wheel  58  rotates along the first lower track  24 , causing the memory nut  68  to move along the threaded spindle  66  away from the gear wheel  58 . When the vehicle seat bottom and upper tracks  18 ,  22  are thereafter moved back toward the last selected use position, the memory nut  68  travels back on the threaded spindle  66  toward the gear wheel  58  until the associated end stops on the memory nut  68  and the gear wheel  58  engage each other, thereby preventing further rearward movement of the vehicle seat bottom and upper tracks  18 ,  22  with respect to the lower tracks  20 ,  24 . 
     Referring now to  FIG. 17 , when the backrest  14  is raised to a use position, the Bowden cable  84  no longer pulls on the activation disc  78 . As a result, the activation disc  78  rotates rearwardly (i.e., counter-clockwise in  FIG. 17 ), disengaging from activation bracket  38 , thereby allowing activation brackets  36 ,  38  to rotate forwardly (i.e., to their inactive positions) through urging by the associated springs, and each of the track locking assemblies  26  to return to the locked position. The reset lever  96 , however, remains in the notch  98  in the additional support bracket  70  (as shown in  FIG. 16 ) and engages the bracket such that the sled  72  is retained its forward, activated position, and, therefore, memory module  52  is also retained in the activated position. Thus, while raising the backrest  14  to its upright (use) position results in loosening the Bowden cable, rotation of the activation brackets  36 ,  38  to their inactive positions, release of buttons  40  and  42 , and, thereby, re-engagement of the track locking assemblies  26  to lock the seat in position at whatever location the backrest is raised to a use position, the memory system remains activated. The memory system is reset only by pulling up on the external release lever  28  as described below. 
     It will be appreciated by those of skill in the art that this disclosed arrangement allows the user to dump the backrest, slide the seat forward, slide the seat back to a position short of the memorized (or originally set) use position, raise the backrest, and lock the seat for use at a position less rearward than the memorized position (such as, for example, when a passenger has occupied the rearward seat, and the front seat passenger wishes to temporarily re-position and lock the front seat at a more forward position to give the rearward passenger more legroom). To return the seat to its memorized position, the backrest may again be dumped forward, thereby disengaging the track locking system, and, since the memory system  50  has not been reset, sliding the seat rearward until further rearward movement is prevented by the memory module  52  as previously described. 
     Referring now to  FIGS. 8 and 18 , the sled  72  may be released from its activated position (and the memory re-set) when the seat release lever  28  is rotated upwardly in order to adjust the longitudinal position of the vehicle seat. As a result, both activation brackets  36 ,  38  rotate rearwardly with the reset activation lever  94  in its not-activated position, such that the reset activation lever  94  engages the reset lever  96  at its forward end and causes the reset lever  96  to rotate forwardly, thereby causing the rearward end  100  of the reset lever  96  to rotate upward out of the notch  98  in the additional support bracket  70  (as shown in  FIG. 15 ). Since the sled is not constrained by the activation lever  76 , sled spring member  86  biases the sled back to its non-activated position, the engagement surface  90  on the sled is moved out of contact with projection  92  on the wheel support bracket  60 , and the wheel assembly  60  pivots upward due to its biasing spring, out of engagement with the lower track  24 . If the vehicle seat is not in the last selected (i.e., memorized) use position when the memory module  52  returns to the non-activated position, the associated clock spring will cause the track gear wheel  58  to rotate back to its initial position in which the end stop of the track gear wheel  58  is engaged with the end stop of the memory nut  68 , thereby resetting the memory module  52  for its next activation. Thus reset, the memory system will re-activate on the next occurrence of dumping the backrest  14  forward. 
       FIGS. 19-25  illustrate a second embodiment of a compensator  274  that may be employed in the disclosed system. Referring in particular to  FIGS. 19 and 20 , in this second embodiment, the compensator  274  includes an outer or upper sled  278  which, in the disclosed system is mounted atop the sled  272  (also referred to herein as the lower or inner sled). In this embodiment a memory activation bracket  275  is pivotally mounted on track locking system activation bracket  238 . A pretensioning spring  277  is disposed between the memory activation bracket  275  and the track locking system activation bracket  238  for biasing the memory activation bracket forwardly (i.e., in the clockwise direction as shown in  FIG. 19 ) to pretension a Bowden cable  284  connected to the activation bracket  275  and the seat back  14 . It should be noted, that in this second disclosed embodiment, the Bowden cable is oriented such that when the seat back is dumped forward and the Bowden cable is retracted, the cable rotates the activation bracket  275  rearwardly (i.e., in the counterclockwise direction as shown in  FIG. 19 ). The activation lever  276  is thus also moved in the rearward direction until it contacts and urges the upper sled  278  in the rearward direction. Thus, in the second embodiment, while the track locking assembly  26  and memory module  52  may be identical to the first disclosed embodiment, the compensator  274  and sled  272  motion will move in the opposite direction (i.e., rearward) to activate the memory module. 
     Still referring to  FIGS. 19 and 20 , activation lever  276  is mounted on the memory activation bracket  275 , and extends across a portion of the top surface of the upper rail  22  such that, as the lever is moved rearward with the rotation of the memory activation bracket  275 , the lever  276  contacts the upper sled  278  and urges the upper sled to slide rearward. As illustrated in  FIG. 20 , the rearward motion of the lever  276 , and thereby the upper sled  278 , urges sled  272  rearward. A cam surface  273  on the underside of lower sled  272  contacts tab  92  on the wheel support bracket  60  as the sled is moved rearward, thereby urging the memory module  52  downward into its activated position. 
     Rotation of the memory activation bracket  275  by the retracting Bowden cable also effectuates a rotation of bracket  238 , thereby depressing seat lock release button  42 , thereby releasing the seat lock track system. Thus, when the seat back  14  is dumped forward, the rearward movement of the activation lever  276  and the upper sled  278  simultaneously urges the sled  272  of the memory system towards its activated position, while causing disengagement of the seat track locking system  24  thereby allowing for slidable movement of the dumped seat. 
     In the circumstance illustrated in  FIG. 20 , the sled  272  is prevent from sliding to its fully rearward, activated position because the gear teeth  62  are not aligned with notches  64 , thereby preventing the wheel assembly  56  from pivoting fully downward to its activated position in engagement with the lower track. Because the lower sled  272  does not slide fully rearward when urged by upper sled  278  under this circumstance, the upper sled  278  continues to move rearward relative to the lower sled  272 , thereby compressing spring  279  and maintaining a rearward force on the lower sled  272 . 
       FIG. 21  illustrates the event where the memory system is activated (by rotation of the memory activation bracket  275 , rearward movement of lever  276  and rearward movement of upper sled  278 ) when the seat is positioned such that the gear teeth  62  are aligned with notches  64  in the lower track. In this situation, the rearward motion of the lower sled  272  (caused by the movement of the upper sled and the force of spring  279 ) forces contact of the cam surface  273  on the sled  272  with tab  92  causing the memory module  52  to pivot downwardly into its active position in engagement with the lower track. 
       FIGS. 22 and 23  illustrate the relative positions of the components of the disclosed system when the backrest is upright (i.e., in the seating position). In this situation the memory module is not activated. The memory activation bracket  275  is biased in its inactive forward position by spring  277 , and each of the upper sled  278  and sled  272  are moved to their inactive forward positions, biased by spring  281 . 
     Referring now to  FIGS. 24 and 25 , in the event the memory module has been first activated (such as, for example, by dumping the seat back forward) and the seatback is thereafter raised to a use position, the Bowden cable  284  will retract and the memory activation bracket will rotate forwardly to its inactive position. At this time, the bracket  238  will also rotate forwardly and upward as a result of the forward position of memory activation bracket  275  thereby allowing the seat track locking assembly  26  to reengage and lock the seat in place at whatever position the seat back is raised to a use position. However, reset lever  296  (shown in  FIG. 24 ) remains in a raised position, interfering with a contact surface on the underside of upper sled  278 , thereby retaining upper sled  278 , and thereby lower sled  272 , in their rearward, activated positions. 
     Thus, where the seatback has been dumped forward, the seat tracks unlock to allow for slidable forward then rearward movement of the folded seat, followed by raising the backrest to a use position, the seat locks in position for use but the seat memory remains activated. Thus the seatback may be dumped, the seat slidably positioned forward, the seat then slidably positioned rearward to a position short of the memorized position (to, for example, allow for use of the front seat at a relatively forward location when the rear seat is occupied). The seat may then again be slidably positioned rearward until it stops as a result of reaching its initial (“memorized”) position. Again, as described above in connection with the first embodiment, the memory system is reset only by pulling up on the external release lever  28 . Activation of the external release lever  28  will cause reset lever  296  to move downwardly thereby allowing upper sled  278  and lower sled  272  to each move to their fully forward, inactivated positions (as shown in  FIG. 23 ). 
     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.