Patent Publication Number: US-10773614-B2

Title: Tip and slide system for a vehicle seat

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. patent application Ser. No. 15/257,157 filed Sep. 6, 2016, entitled TIP AND SLIDE SYSTEM FOR A VEHICLE SEAT, the entire disclosure of which is hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention generally relates to vehicle seats, and more specifically, to a foldable vehicle seat that provides access to a rear portion of a passenger cabin of the vehicle. 
     BACKGROUND OF THE INVENTION 
     Various automobiles include multiple seating areas within a passenger cabin. Certain portions of the passenger cabin do not have an exterior door that directly serves that area within the passenger cabin, such as a third row seating area, or a second row seating area within certain two-door vehicles. In order to access these areas of the passenger cabin, certain vehicle seats are able to be moved forward in order to allow for access within these rear portions of the passenger cabin. Typically, these seats perform a combination of tilting and sliding operations to provide such access. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, a vehicle seat includes a seatback having a seatback pivot rotationally coupled to a base. The seatback is selectively operable about the seatback pivot between an upright position, a folded position and a rear-entry position. The rear-entry position is defined between the upright and folded positions. An overslide cam is selectively operable to an activation state that activates an overslide mechanism that selectively defines a sliding operation of the base to a forward-most position. A rear-access lever is in communication with the seatback pivot and the overslide cam, wherein operation of the rear-access lever to an engaged state places the overslide cam in a ready position proximate the seatback pivot. A return pawl extends outwardly from an outer edge of the seatback pivot. Rotation of the seatback pivot into the rear-entry position when the overslide cam is in the ready position further defines the activation state. In the activation state, co-axial rotation of the seatback pivot and the return pawl about a center of the seatback pivot rotates the overslide cam to activate the overslide mechanism. Operation of the rear-access lever when the seatback pivot is proximate the rear-entry position defines a non-activation state. In the non-activation state, movement of the overslide cam to the ready position deflects the return pawl toward the seatback pivot such that the overslide cam is free of rotation relative to the seatback pivot and the return pawl. 
     According to another aspect of the present invention, a vehicle seat includes a seatback pivot, a rear-access lever that rotates an overslide cam and a pawl of the seatback pivot. Operation of the rear-access lever with the seatback pivot in a first radial range defines selective rotation of the overslide cam by the pawl. Operation of the rear-access lever with the seatback pivot in a second radial range defines a deflection of the pawl by the overslide cam. 
     According to yet another aspect of the present invention, a vehicle seat includes a seatback pivot rotationally operable relative to a base. A rear access lever rotates an overslide cam to a ready position relative to the seatback pivot. A pawl is attached to the seatback pivot that selectively defines an activation state where the pawl selectively rotates the overslide cam away from the ready position and a non-activation state wherein the overslide cam deflects the pawl toward the seatback pivot. 
     These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a side perspective view of a vehicle having seats that incorporate an aspect of the tip and slide mechanism incorporated therein; 
         FIG. 2  is a perspective view of the second row of seating within the passenger cabin of the vehicle of  FIG. 1 ; 
         FIG. 3  is a partial elevation view of the seat structure incorporating the tip and slide mechanism; 
         FIG. 4  is a partial elevational view of the seat frame of  FIG. 3  showing the seatback moved to a rear-entry position; 
         FIG. 5  is a partial elevational view of the seat frame of  FIG. 4  with the seat moved forward to the forward-most comfort position; 
         FIG. 6  is a partial elevational view of the seat frame of  FIG. 5  with the seat moved past the forward-most comfort position and into a forward-most non-seating position; 
         FIG. 7  is an enlarged elevational view of an aspect of the track overslide actuator incorporated within the seat frame, showing the track overslide actuator in a deactivated state; 
         FIG. 8  is a partially exploded view of a seatback pivot with an aspect of the bracket interlock module removed therefrom; 
         FIG. 9  is an exploded perspective view of an aspect of the bracket interlock module of  FIG. 8 ; 
         FIG. 10  is an enlarged elevational view of the overslide actuator; 
         FIG. 11  is an exploded perspective view of an aspect of the rear access lever for operating the overslide cam of  FIG. 10 ; 
         FIG. 12  is an enlarged elevational view of an aspect of the overslide actuator of  FIG. 10  and showing the seatback pivot in a deactivated state; 
         FIG. 13  is an elevational view of the overslide actuator of  FIG. 12  with the seatback pivot in the deactivated state and the overslide cam moved into the ready position; 
         FIG. 14  is an elevational view of the overslide actuator of  FIG. 10  showing the rear access lever in an idle state; 
         FIG. 15  is an opposing elevational view of the seat frame of  FIG. 15  and illustrating an aspect of the seat-rotating mechanism; 
         FIG. 16  is an elevational view of the actuating assembly of  FIG. 14  showing the rear access lever in an engaged state and the overslide cam in a ready position; 
         FIG. 17  is an opposing elevational view of the seatback pivot of  FIG. 16  showing the seat-rotating mechanism being activated by the rear access lever; 
         FIG. 18  is an elevational view of the seatback pivot of  FIG. 17  showing the seatback pivot moving toward the rear-entry position; 
         FIG. 19  is an enlarged elevational view of the engagement between an actuating surface of the rear access lever and the overslide cam; 
         FIG. 20  is an enlarged elevational view of an aspect of the track overslide actuator in an activated state; and 
         FIG. 21  is an enlarged elevational view of an aspect of the seatback pivot incorporating the interlock cam having a plurality of blocking surfaces defined therein. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     As shown in  FIGS. 1-6 , reference numeral  10  generally refers to a tip and slide mechanism for a vehicle  12  incorporated within a vehicle seat  14  for allowing access to rear portions  16  of a passenger cabin  18  of the vehicle  12 . The vehicle seat  14  includes a seatback  20  having a seatback pivot  22  that is rotationally coupled to a base  24  at a rear access assembly  26 . The seatback  20  is selectively operable about the seatback pivot  22  between a plurality of rotational positions  40 . The base  24  is also slidable along a track  28  in at least a plurality of comfort positions  30 . A rear access lever  32  is disposed in communication with the seatback pivot  22  and the rear access assembly  26 . Operation of the rear access lever  32  from an idle state  34  to an engaged state  36  places the rear access assembly  26  in a ready position  38 . It is contemplated that the ready position  38  at least partially obstructs the rotation of the seatback pivot  22  from defining the plurality of rotational positions  40  of the seatback  20 . A track overslide actuator  42  of the rear access assembly  26  is disposed in communication with the seatback pivot  22  and the track  28 . It is contemplated that after the rear access assembly  26  is placed in the ready position  38  through operation of the rear access lever  32 , operation of the seatback pivot  22  to a rear-entry position  54  serves to activate the track overslide actuator  42 . Activation of the track overslide actuator  42 , in turn, serves to provide slidable forward operation  44  of the base  24  along the track  28  and beyond the plurality of comfort positions  30  to a rear-access position  46 . An interlock actuator  48  of the rear access assembly  26  is disposed in communication with the seatback pivot  22  and the track  28 . When the track overslide actuator  42  is activated, forward operation  44  of the base  24  along the track  28  from a home position  50  activates the interlock actuator  48  into a blocking position  52 . The blocking position  52  of the interlock actuator  48  serves to rotationally lock the seatback pivot  22  and, in turn, the seatback  20  in the rear-entry position  54 . Subsequent rearward sliding movement  58  of the base  24  back toward and into the home position  50  of the base  24  serves to disengage the interlock actuator  48  from the blocking position  52 . Moreover, movement of the seatback pivot  22  from the rear-entry position  54  to an upright position  56  serves to disengage the track overslide actuator  42 . 
     Referring now to  FIGS. 3-13 , the seatback  20  is selectively operable about the seatback pivot  22  between the plurality of rotational positions  40 . These rotational positions  40  can include the upright position  56 , a folded position  70  and the rear-entry position  54 . According to various embodiments, it is contemplated that the rear-entry position  54  is defined between the upright and folded positions  56 ,  70 . An overslide cam  72  of the track overslide actuator  42  is selectively operable into an activation state  74  that serves to activate an overslide mechanism  76  of the track overslide actuator  42  that selectively defines the sliding operation of the base  24  beyond the plurality of comfort positions  30  and to the rear-access position  46 . The rear access lever  32  is adapted to be in communication with the seatback pivot  22  and the overslide cam  72 . Operation of the rear access lever  32  to the engaged state  36  serves to place the overslide cam  72  in the ready position  38  proximate the seatback pivot  22 . A return pawl  78  extends outwardly from an outer edge  80  of the seatback pivot  22 . It is contemplated that rotation of the seatback pivot  22  into the rear-entry position  54 , when the overslide cam  72  is in the ready position  38 , further defines the activation state  74 . In this manner, when in the activation state  74 , co-axial rotation of the seatback pivot  22  and the return pawl  78  about a center  82  of the seatback pivot  22  rotates the overslide cam  72  to activate the overslide mechanism  76 . Operation of the rear access lever  32  when the seatback pivot  22  is proximate the rear-entry position  54 , such that the overslide cam  72  is positioned adjacent to the return pawl  78 , defines a non-activation state  84 . In the non-activation state  84 , movement of the overslide cam  72  into the ready position  38  serves to deflect the return pawl  78  toward the seatback pivot  22  such that the overslide cam  72  is free of rotation relative to the seatback pivot  22  and the return pawl  78 . Accordingly, in the non-activation state  84 , rotation of the seatback pivot  22  and the return pawl  78  about the center  82  of the seatback pivot  22  slides the return pawl  78  against the overslide cam  72  such that the overslide cam  72  is not rotated out of the ready position  38  and the overslide mechanism  76 , in turn, is not activated. 
     Referring again to  FIGS. 7-13 , it is contemplated that the return pawl  78  is outwardly biased relative to the seatback pivot  22 . In the non-activation state  84 , when the overslide cam  72  moves to the ready position  38 , the pawl  78  is deflected to a deflected state  86 . This deflection of the return pawl  78  is defined by rotation of the return pawl  78  about a pawl pivot  90 . It is contemplated that the pawl pivot  90  is positioned distal from the center  82  of the seatback pivot  22 . Typically, the pawl pivot  90  will be positioned proximate the outer edge  80  of the seatback pivot  22 . According to the various embodiments, the return pawl  78 , in a non-deflected position, extends outward from the outer edge  80  of the seatback pivot  22 . Accordingly, at least a portion of the return pawl  78  stands proud with respect to the outer edge  80  of the seatback pivot  22 . 
     In the activation state  74 , when the overslide cam  72  is in the ready position  38 , the overslide cam  72  is positioned such that rotation of the seatback pivot  22  and the pawl  78  will allow those portions of the return pawl  78  that are proud of the seatback pivot  22  to engage the overslide cam  72  to define the activation state  74  of the overslide cam  72  and the overslide mechanism  76 . It is contemplated that when the overslide cam  72  is in the ready position  38  in both the activation and non-activation states  74 ,  84 , the overslide cam  72  is free of direct engagement with the outer edge  80  of the seatback pivot  22 . 
     Referring again to  FIGS. 7-13 , it is contemplated that the return pawl  78  can include a return spring  100  that outwardly biases the return pawl  78  to an outward state  102  of the return pawl  78 . It is contemplated that, in the non-activation state  84 , movement of the return pawl  78  to the deflected state  86  by the overslide cam  72  serves to selectively overcome the biasing force applied by the return spring  100 . Slidable disengagement of the overslide cam  72  from the return pawl  78  thereby allows the return spring  100  to bias the return pawl back into the outward state  102 . In this manner, the outward state  102  of the return pawl  78  is defined by portions of a return pawl  78  standing proud of the outer edge  80  of the seatback pivot  22 . When the return pawl  78  is in the deflected state  86 , the portions of the return pawl  78  that typically stand proud of the outer edge  80  of the seatback pivot  22  are deflected inward to be more in-line with the outer edge  80  of the seatback pivot  22 . Because the overslide cam  72 , in the ready position  38 , is free of engagement with the outer edge  80  of the seatback pivot  22 , the return pawl  78  in the deflected state  86  may still be positioned slightly outward of the outer edge  80  of the seatback pivot  22 . This configuration allows for the slidable engagement between the overslide cam  72  and the return pawl  78  indicative of the non-activation state  84 . 
     Referring again to  FIGS. 7-13 , it is contemplated that the return pawl  78  can include an engaging portion  110  and a deflecting portion  112 . The engaging portion  110  of the return pawl  78  is adapted to selectively engage the overslide cam  72  when in the ready position  38  and when the tip and slide mechanism  10  defines the activation state  74 . In this manner, rotation of the seatback pivot  22  to the rear-entry position  54  serves to cause the engaging portion  110  of the return pawl  78  to push against the overslide cam  72  and rotate the overslide cam  72  in the activation state  74  to activate the overslide mechanism  76 . The deflecting portion  112  of the return pawl  78  is adapted to receive an end portion  114  of the overslide cam  72  when in the non-activation state  84 . In this manner, the deflecting portion  112  is adapted to be biased by the end portion  114  of the overslide cam  72  and also slide against portions of the overslide cam  72  to prevent rotation of the overslide cam  72  that would typically define the activation state  74 . According to the various embodiments, the engaging portion  110  can be a surface that extends generally radially outward from the seatback pivot  22 , such that the engaging portion  110  can engage and push against the end portion  114  of the overslide cam  72  to define the activation state  74 . Conversely, the deflecting portion  112  of the return pawl  78  is positioned generally concentric with a center  82  of the seatback pivot  22  and generally perpendicular with the engaging portion  110  of the return pawl  78 , such that a minimum amount of friction is experienced between the deflecting portion  112  of the return pawl  78  and the end portion  114  of the overslide cam  72 . 
     Referring now to  FIGS. 3-19 , the use of the return pawl  78  can be used to prevent certain failure modes of the track overslide actuator  42  from occurring, and more specifically, certain failure modes of the rear access lever  32 . The incorporation of the return pawl  78  allows for operation of the rear access lever  32  to move the overslide cam  72  into the ready position  38  in both the activation state  74  and non-activation state  84 . Accordingly, certain failure modes of the track overslide actuator  42  may not result in excessive tension being placed upon the cable  120  extending from the tip and slide actuator  122  (shown in  FIG. 2 ) positioned at the top region  124  of the vehicle seat  14  and the rear-access lever  32 . The failure mode is communicated to the user, not through failure at the tip and slide actuator  122 , but by the seatback  20  and seatback pivot  22  rotating forward and beyond the rear-access position  46 . This over-rotation provides an indication to the user that the engaging portion  110  of the return pawl  78  did not engage with the overslide cam  72  to define the activation state  74 . Rather, the failure mode is defined by the overslide cam  72  pushing against the deflecting portion  112  of the return pawl  78  to define the deflected state  86 , the return pawl  78  and the seatback pivot  22  can thereby be rotated beyond the rear-entry position  54  and into the folded position  70  of the seatback  20 , if desired. The user can then return the seatback pivot  22  toward the upright position  56 . Once the seatback pivot  22  is rotated a sufficient rotational distance, the overslide cam  72  disengages the deflecting portion  112  of the return pawl  78  and the return spring  100  biases the pawl  78  to the outward state  102 . By rotating the seatback pivot  22  in this fashion, the user can place the tip and slide mechanism  10  in the activation state  74  without rotating the seatback  20  all the way back to the upright position  56  and without resetting the rear-access lever  32 . 
     Referring again to  FIGS. 3-19 , it is contemplated that the return pawl  78  can be included within a bracket interlock module  130  that attaches to the outer edge  80  of the seatback pivot  22 . In this manner, the bracket interlock module  130  can be a separate piece that is fastened, welded, adhered, or otherwise attached to the outer edge  80  of the seatback pivot  22 . In such an embodiment, it is contemplated that the pawl pivot  90  is located within a portion of the bracket interlock module  130 . Additionally, it is contemplated that the return spring  100  that outwardly biases the return pawl  78  toward the outward state  102  can be attached to the return pawl  78  and a body  132  of the bracket interlock module  130 . According to various embodiments, it is also contemplated that the return pawl  78  can be attached directly to a portion of the seatback pivot  22 . 
     According to the various embodiments, the return pawl  78  can be outwardly biased through various mechanisms that can include a torsion spring, a linear spring, elastomeric members, compressible and elastic members, combinations thereof, and other similar elastic and deflectable-type materials. Through the use of such deflecting mechanisms and materials, it is contemplated that the return pawl  78  can be moved to the deflected state  86  through a rotation, as discussed above, or can be moved to the deflected state  86  through a linear movement that serves to compress the biasing member in a generally axial direction. In various embodiments, it is contemplated that the return pawl  78  can itself be an elastic member such that when the overslide cam  72  engages the deflecting portion  112  of the return pawl  78 , the return pawl  78  itself deflects in shape or bends, twists, or otherwise deforms to define the non-activation state  84  of the track overslide actuator  42 . 
     Referring now to  FIGS. 14-18 , the vehicle seat  14  can include a seat-rotating mechanism  140  disposed proximate the seatback pivot  22 . The seat-rotating mechanism  140  can serve to selectively operate the seatback  20  at least between the upright and folded positions  56 ,  70 . It is contemplated that the operation of the overslide cam  72  to at least the activation state  74  serves to engage the seat-rotating mechanism  140 . It is contemplated that operation of the seatback  20  from the folded position  70  and/or the rear-access position  46  back to the upright position  56  serves to disengage the seat-rotating mechanism  140 . It is contemplated that the seat-rotating mechanism  140  can include an activation arm  142  that extends from a center  82  of the seatback pivot  22 . The activation arm  142  engages a seat-rotating link  144  that extends from the activation arm  142  to a secondary portion  146  of the rear access lever  32 . Operation of the rear access lever  32  to the engaged state  36  also operates the secondary portion  146  in a simultaneous rotational manner. It is contemplated that the rear access lever  32  and the secondary portion  146  are fixedly coupled together such that operation of the rear access lever  32  serves to simultaneously operate the secondary portion  146  of the rear access lever  32 . 
     Referring again to  FIGS. 14-18 , when the rear access lever  32  is moved to the engaged state  36 , the secondary portion  146  moves the seat-rotating link  144  in a substantially linear direction that also pulls on the activation arm  142  of the seat-rotating mechanism  140  to engage the seat-rotating mechanism  140 . In this manner, operation of the rear access lever  32  to the engaged state  36  serves to also automatically activate the seat-rotating mechanism  140  to allow for rotation of the seatback  20  and the seatback pivot  22  from the upright position  56  to at least the rear-entry position  54 , and in a non-activation state  84 , all the way to the folded position  70 . It is contemplated that the seat-rotating mechanism  140  can be adapted to disengage once the seatback  20  and/or the seatback pivot  22  are moved to the upright position  56 . As will be discussed more fully below, portions of the tip and slide mechanism  10  of the vehicle seat  14  can include separate mechanisms for maintaining a temporarily fixed position of the seatback  20  and seatback pivot  22  in the rear-entry position  54 . These mechanisms can include the interlock actuator  48  that defines one or more blocking positions  52  of an interlock cam  150  for engaging interlock surface  152  defined within one of the seatback pivot  22  and/or the bracket interlock module  130 . 
     Referring now to  FIGS. 7-19 , the rear access lever  32  can include an actuating surface  160  that engages a lever portion  162  of the overslide cam  72 . In such an embodiment, operation of the rear access lever  32  rotates the actuating surface  160  against the portion of the overslide cam  72  to rotate the overslide cam  72  into the ready position  38 . It is contemplated that the actuating surface  160  can be concentric with the operation of the rear access lever  32 . Accordingly, the actuating surface  160  of the rear access lever  32  can maintain the overslide cam  72  in the ready position  38 , until the overslide cam  72  moves away from the ready position  38  to define the activation state  74  of the tip and slide mechanism  10 . 
     Referring again to  FIGS. 7-19 , it is contemplated that the actuating surface  160  of the rear access lever  32  can extend around only a portion of the rear access lever  32 . In this manner, the actuating surface  160  can define a leading edge  164  that can abut the lower portion of the overslide cam  72  and help to push the overslide cam  72  towards the ready position  38 . The outer face  166  of the actuating surface  160  then maintains engagement with the lower portion and holds the overslide cam  72  in the ready position  38  until the overslide cam  72  rotates in the activation state  74 . It is contemplated that the operation of the seatback pivot  22  toward the rear-access position  46  rotates the overslide cam  72  such that the lever portion  162  of the overslide cam  72  disengages from the actuating surface  160 . A biasing mechanism disposed within the rear access lever  32  can return the rear access lever  32  to the idle state  34 . Engagement of the return pawl  78  with the overslide cam  72  maintains the position of the overslide cam  72  in the activation state  74  until such time as the seatback pivot  22  is returned to the upright position  56 . 
     According to the various embodiments, the vehicle seat  14  can include the seatback pivot  22 , and the rear access lever  32  that rotates the overslide cam  72 . The return pawl  78  of the seatback pivot  22  can be adapted such that operation of the rear-access lever  32  with the seatback pivot  22  within a first radial range  170  defines selective rotation of the overslide cam  72  by the return pawl  78 . It is contemplated that the first radial range  170  of the seatback pivot  22  can be defined between any of the reclined positions  172 , the upright position  56  and up to, but typically not including, the rear-access position  46 . As discussed above, it is typical that the rear-access position  46  serves to define the non-activation state  84  of the tip and slide mechanism  10  where the end portion  114  of the overslide cam  72  is aligned with the deflecting surface of the return pawl  78 . It is also contemplated that operation of the rear access lever  32  when the seatback pivot  22  is in a second radial range  174  defines a deflection of the pawl  78  by the overslide cam  72 . It is contemplated that this second radial range  174  can be defined by a rotation of the seatback pivot  22  and the seatback  20  within and near the return pawl  78 , such that the end portion  114  of the overslide cam  72  is aligned with the deflecting portion  112  of the return pawl  78 . It is contemplated that when the rear access lever  32  is operated to the engaged state  36  and the seatback pivot  22  is in the first radial range  170 , movement of the seatback  20  toward the second radial range  174 , (i.e., toward the rear-access position  46 ) serves to move the overslide cam  72  to define the overslide position  176  of the overslide cam  72 . 
     Referring now to  FIGS. 7-21 , the vehicle seat  14  can include the seatback pivot  22  that is rotationally operable relative to the base  24 . The rear access lever  32  serves to rotate the overslide cam  72  to the ready position  38  relative to the seatback pivot  22 . The return pawl  78  is attached to the seatback pivot  22 , either directly or through the bracket interlock module  130 . It is contemplated that the return pawl  78  selectively defines the activation state  74  where the return pawl  78  selectively rotates the overslide cam  72  away from the ready position  38  to the overslide position  176 . The return pawl  78  may also define a non-activation state  84  wherein the overslide cam  72  deflects the return pawl  78  toward the seatback pivot  22 . The activation state  74  can further be defined by activation of the seatback pivot  22  from the upright position  56  toward the rear-entry position  54 , where the rotation of the seatback  20  rotates the pawl  78  into engagement with the end portion  114  of the overslide cam  72  in the ready position  38 . It is contemplated that the non-activation state  84  can be further defined by the seatback pivot  22  being proximate the rear-entry position  54  and the overslide cam  72  being moved to the ready position  38 . In such a condition, the operation of the overslide cam  72  into the ready position  38  and in the non-activation state  84  deflects the pawl  78  such that the pawl  78  slidably engages the overslide cam  72  when the overslide cam  72  is free of rotation to the overslide position  176  until such time as the seatback pivot  22  is returned to the upright position  56 , or other predetermined rotational position  40  adapted to disengage the overslide cam  72  and the remainder of the tip and slide mechanism  10 . 
     Referring again to  FIGS. 7-21 , it is contemplated that the overslide cam  72 , when defined in the activation state  74 , allows for selected forward operation  44  of the base  24  in a home position  50  and beyond the forwardmost comfort position  180  and into the rear-entry position  54 . This movement of the base  24  toward the rear-entry position  54  activates the interlock cam  150  to define a blocking position  52  of a plurality of blocking positions  52 . It is contemplated that each blocking position  52  can correspond to a respective blocking surface  182  of the interlock cam  150 . Each respective blocking surface  182  is adapted to engage an interlock surface  152  disposed proximate the seatback pivot  22 . It is further contemplated that engagement of one of the respective blocking surfaces  182  with the interlock surface  152  serves to selectively retain the seatback pivot  22  in the rear-entry position  54  until the base  24  is returned to the home position  50  or other lateral position selected to correspond to disengagement of the interlock cam  150  with the interlock surface  152 . While two blocking surfaces  182  are shown in the figures, it is contemplated that additional blocking surfaces  182  can be incorporated into the interlock cam  150 . As discussed above, each blocking surface  182  corresponds to a respective blocking position  52  that retains the seatback pivot  22  in the rear-entry position  54 . 
     According to various embodiments, it is contemplated that the plurality of blocking surfaces  182  of the interlock cam  150  can be used where portions of the track overslide actuator  42  do not fully rotate as intended. Such lack of full rotation can be the result of an obstruction, insufficient lubrication, possible damage to the system, combinations thereof, or other similar condition that may prevent full operation of the track overslide actuator  42 . 
     It is also contemplated that the lack of full operation of the interlock cam  150  can be the result of a tolerance stack-up where one portion of the tip and slide mechanism  10  may not be capable of full operation such that portions of the tip and slide mechanism  10  operated thereafter may, in turn, only be capable of less than full operation. The incorporation of the plurality of blocking surfaces  182  of the interlock cam  150  can serve to at least partially account for this tolerance stack-up without diminishing the effectiveness or operation of the entire tip and slide mechanism  10 . The use of the plurality of blocking surfaces  182  allows for less than full rotation of the interlock cam  150  to engage the interlock surface  152  and lock the seatback pivot  22  and the seatback  20  in the rear-entry position  54 . 
     It is contemplated that the incorporation of the return pawl  78  and the plurality of blocking surfaces  182  of the interlock cam  150  serve to minimize the occurrence of failure modes and overexertion of certain components of the tip and slide mechanism  10 . As such, these components promote smooth and efficient use of the tip and slide mechanism  10  for allowing occupants of the vehicle  12  to access portions of the passenger cabin  18 . 
     It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.