Patent Abstract:
A convertible roof includes a segmented pair of front roof rails that in-fold when being retracted, thereby reducing the packaging space required to stow the convertible roof. The in-folding of the segmented front roof rails is controlled by linkages between the segmented portions and the number one roof bow and synchronizes and constrains the in-folding of the segmented front roof rails. A dampening device is utilized to dampen a portion of the movement of the top stack mechanism between extended and retracted positions.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/612,384, filed on Sep. 23, 2004. The disclosure of the above application is incorporated herein by reference. 
     
    
     BACKGROUND AND SUMMARY OF THE INVENTION  
       [0002]     The present invention relates to convertible roofs and, more particularly, to in-folding convertible roofs.  
         [0003]     Traditional soft-top convertible roofs for automotive vehicles typically employ three, four or five roof bows, having an inverted U-shape spanning transversely across the vehicle for supporting a vinyl, canvass or polyester fabric pliable roof cover. A number one roof bow is mounted to a pair of front roof rails and is typically latched to a stationary front header panel of the automotive vehicle body disposed above the front windshield. A number two roof bow is typically mounted to either the front roof rails or to a pair of center roof rails which are pivotally connected to the front roof rails. Furthermore, a number three, four and any additional optional roof bows are commonly mounted to either the center pair of roof rails or to a pair of rear roof rails which are pivotally coupled to the center roof rails. The roof cover can also have a hard or rigid portion along with the pliable portion. For example, reference should be made to U.S. Pat. No. 5,429,409 entitled “Convertible Top”, which is incorporated by reference herein.  
         [0004]     Most traditional convertible roofs are stowed in a bootwell or stowage compartment that is located aft of a passenger compartment in the vehicle. A boot or tonneau cover is then used to cover the bootwell and conceal the convertible roof from view and/or protect the stowed roof from the environment. Optionally, a portion of the convertible roof can be visible when in the stowed position and provide a desired appearance for the vehicle.  
         [0005]     Traditional soft-top convertible roofs, such as those discussed above, can present a packaging (stowing) difficulty when it is desired to use a “Z” folding roof. The difficulty is more pronounced when a “Z” folding roof is desired to be used on a larger vehicle (vehicle having front and rear seating areas). Additionally, the use of three pairs of coupled roof rails also adds to the packaging difficulty. The three pairs of coupled roof rails are pivoted relative and stacked upon one another. The packaging size of such a retraction mechanism requires the stowage compartment to accommodate the various lengths of the roof rails.  
         [0006]     The available space for the stowage compartment in a vehicle, however, may be at a premium. That is, while it is desirable to provide a vehicle with a convertible roof, it is also desirable to provide sufficient storage space in the vehicle for use in storing objects other than the convertible roof. Thus, it would be advantageous to minimize the packaging space required to stow the convertible roof while maximizing the available space for other purposes, such as maintaining or increasing the size of the passenger compartment and/or the size of the general storage area or trunk of the vehicle when produced with a convertible roof.  
         [0007]     Moreover, when the convertible roof spans a large passenger seating area the controlling of the final movements of the convertible roof when being raised or retracted may cause significant stress or torque to be exhibited on the components of the convertible roof. This increased force may be undesirable and may cause a reduction in the lifespan of the components that comprise and drive the convertible roof. Thus, it would be advantageous to minimize the impact or force imparted on the driving components of the convertible roof when reaching the fully extended or fully retracted state.  
         [0008]     In accordance with the present invention, a convertible roof is provided which includes a segmented pair of front roof rails that in-fold when being retracted. The in-folding advantageously reduces the packaging space required to stow the convertible roof. In another aspect of the present invention, in-folding of the segmented front roof rails is controlled by synchronizing linkages between the segmented portions and the number one roof bow which synchronize the in-folding of the segmented front roof rails. The synchronization advantageously eliminates side-to-side drift of the convertible roof when moving between the raised and stowed positions. In accordance with another aspect of the present invention, a damper is employed to dampen a portion of the motion of the convertible roof as the top reaches a fully extended and fully retracted position. The dampening advantageously reduces high forces or stresses that are imparted on the drive mechanisms during the movement of the convertible roof between the extended and retracted positions.  
         [0009]     Along with reducing the packaging space and/or excessive force or stress, additional objects, advantages and features of the present invention will become apparent from the following description and the pending claims, taken in conjunction with the accompanying drawings. It should be understood that the detailed description and the specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0011]      FIG. 1  is a perspective view of an automotive vehicle having an alternate embodiment of a convertible roof according to the principles of the present invention showing the convertible roof in the raised position;  
         [0012]      FIGS. 2A-2C  are various views of the convertible roof of  FIG. 1  in an intermediate position between the raised and stowed positions;  
         [0013]      FIGS. 3A and 3B  are respective side elevation and plan views of the convertible roof of  FIG. 1  in the stowed position;  
         [0014]      FIGS. 4A and 4B  are fragmented perspective views of a portion of the convertible roof of  FIG. 1  respectively in a raised position and partially retracted position showing the linkage assemblies between the center and front roof rail and between the segmented portions of the front roof rail;  
         [0015]      FIG. 5  is a simplified schematic representation of the various linkage assemblies used in the segmented front roof rail to provide the in-folding of a portion of the front roof rail in the convertible roof of  FIG. 1 ;  
         [0016]      FIG. 6  is a perspective view of an automotive vehicle having a preferred embodiment of a convertible roof according to the principles of the present invention showing the convertible roof in the raised position;  
         [0017]      FIG. 7  is a perspective view of the convertible roof of  FIG. 6  in an intermediate position between the raised and stowed positions;  
         [0018]      FIGS. 8A and 8B  are respective perspective and top plan views of the convertible roof of  FIG. 6  in the stowed position;  
         [0019]      FIGS. 9A and 9B  are fragmented perspective views of a portion of the convertible roof of  FIG. 6  respectively in a raised position and partially retracted position showing the linkage assemblies between the center and front roof rails and between the segmented portions of the front roof rail;  
         [0020]      FIG. 10  is a bottom plan view of the front portion of the convertible roof of  FIG. 6  showing the details of the synchronizing linkage assemblies when the convertible roof is in the raised position;  
         [0021]     FIGS.  11 A-C are side fragmented simplified cutaway views illustrating the attachment of the rear roof rail to the fixed pivot and the damper attached to the rear roof rail of the convertible roof of  FIG. 6  in a stowed, intermediate and raised position, respectively; and  
         [0022]      FIGS. 12A and 12B  are bottom plane views of alternate embodiments of synchronizing linkage assemblies according to the principles of the present invention that can be used with an in-folding convertible roof. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]     The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. As used herein, the term “substantially perpendicular” allows for some limited deviation from 90°, such as 90°±5°.  
         [0024]      FIGS. 1-5  show an alternate embodiment of an in-folding convertible roof  20  according to the principles of the present invention. Convertible roof  20  is employed on an automotive vehicle  22  having a passenger compartment  24  with front and rear passenger seating areas  26 ,  28  and a generally U-shaped bootwell or stowage compartment  30 . Stowage compartment  30  is positioned aft of passenger compartment  24  with quarter trim portions extending along a portion of sides of passenger compartment  24 . Convertible roof  20  is of the type utilizing a folding or top stack mechanism  34  and a roof cover  36  (shown in  FIG. 2A  only) and is operable between a fully raised position, as shown in  FIG. 1 , through intermediate positions, such as those shown in  FIGS. 2A-2C , to a fully stowed position, as shown in  FIGS. 3A and 3B . Roof cover  36  is made from a pliable material, such as vinyl, canvass or a polyester fabric. If desired, roof cover  36  can include a hard or rigid portion that, optionally, can be covered by the same material that comprises the soft portion of the cover to give a uniform appearance. A backlight (not shown) is attached to roof cover  36  and is not pivotally coupled to top stack mechanism  34 . For example, reference should be made to U.S. Pat. No. 5,887,936 titled “Backlight System for Use in an Automotive Vehicle Convertible Roof,” by Cowsert, and U.S. Pat. No. 6,102,467 titled “Backlight Retention System for Use in an Automotive Vehicle Convertible Roof,” by Laurain et al., both of which are herein incorporated by reference. The backlight can be made of either a rigid material, such as glass, or a pliable transparent material, such as vinyl.  
         [0025]     In the figures, convertible roof  20  and top stack mechanism  34  are shown symmetrical about a longitudinal, fore-and-aft center line  40  (shown in  FIG. 3B ) of vehicle  22 . Center line  40 , thus, also serves as a longitudinal center line for convertible roof  20  and top stack mechanism  34 . Top stack mechanism  34  includes right and left roof linkages on the respective right and left sides of vehicle  22 . For brevity, at times only one side of top stack mechanism  34  and convertible roof  20  may be shown and/or discussed. However, it should be understood that the other side linkages are also provided as part of top stack mechanism  34  and convertible roof  20  and are mirrored images of the side depicted and/or discussed. Also, when using the terms “fore” and “aft,” “front” and “back,” and “forward” and “rearward” in describing the movement and components of top stack mechanism  34  and convertible roof  20 , such reference refers to the orientation of the components when top stack mechanism  34  and convertible roof  20  are in the fully raised position.  
         [0026]     Top stack mechanism  34  includes a number one roof bow  44  that extends transversely across vehicle  22  and is disposed above the front windshield header when in the fully raised position, as shown in  FIG. 1 . Roof cover  36  is attached to number one roof bow  44 . Number one roof bow  44  is coupled to a pair of segmented front roof rails  46  by synchronizing linkage assemblies  48 , described in more detail below.  
         [0027]     Segmented front roof rails  46  include an in-folding portion  46   a  and a straight-folding portion  46   b.  In-folding and straight-folding portions  46   a,    46   b  are pivotally connected together at pivot  50  and are interconnected by in-folding linkage assemblies  52 , described in more detail below. Straight-folding portions  46   b  are pivotally connected to front portions of a pair of center roof rails  54  at pivots  56  and are interconnected with intermediate linkage assemblies  57 , described in more detail below.  
         [0028]     Rear portions of center roof rails  54  are pivotally connected to front or top portions of rear roof rails  58  at pivots  60 . Referring now to  FIG. 2A , the opposite ends of rear roof rails  58  are pivotally connected to fixed brackets  62  at pivots  64 . Pivots  64  are aligned along a pivot axis  65  which is generally perpendicular to longitudinal center line  40 . Rear roof rails rotate about pivots  64  and pivot axis  65  during extension and retraction of top stack mechanism  34 , as describe below. Brackets  62  are fixed to vehicle  22  within stowage compartment  30 .  
         [0029]     Still referring to  FIG. 2A , one end of a balance link  66  is pivotally coupled to bracket  62  at pivot  68  while an opposite end of balance link  66  is pivotally coupled to a rear portion of center roof rail  54  at pivot  70 . The interconnection between center roof rail  54 , rear roof rail  58 , bracket  62  and balance link  66  forms a rear four-bar linkage assembly defined by pivots  60 ,  64 ,  68  and  70 . A fluidic actuator  71  is pivotally connected to vehicle  22  and balance link  66 . Actuator  71  is operable to move top stack mechanism  34  and convertible roof  20  between the raised and stowed positions, as described in more detail below. For brevity, a portion of the rear linkage assembly (balance link  66  and bracket  62 ) along with actuator  71  are shown only in  FIG. 2A .  
         [0030]     The rear linkage assembly and intermediate linkage assembly  57  are interconnected by a control link  72 . One end of control link  72  is pivotally connected to an extension of rear roof rail  58  at pivot  74 . An opposite end of control link  72  is pivotally connected to intermediate linkage assembly  57  at pivot  76 . Control link  72  causes intermediate linkage assembly  57  to rotate front roof rail  46  relative to center roof rail  54  during extension and retraction of top stack mechanism  34 , as described in more detail below.  
         [0031]     Intermediate linkage assembly  57 , as best seen in  FIGS. 4A and 4B , interconnects straight-folding portion  46   b  of front roof rail  46  with center roof rail  54 . Intermediate linkage assembly  57  includes a first link  80  having an intermediate portion pivotally connected to straight-folding portion  46   b  at pivot  82  while an end is pivotally connected to one end of a second link  84  at pivot  76 . An opposite end of second link  84  is pivotally connected to an intermediate portion of center roof rail  54  at pivot  86 . Intermediate linkage assembly  57  forms a four-bar linkage assembly including straight-folding portion  46   b,  first link  80 , second link  84  and center roof rail  54  and is defined by pivots  82 ,  76 ,  86  and  56 . Intermediate linkage assembly  57  controls the movement of front roof rail  46  relative to center roof rail  54  during the movement of top stack mechanism  34  between the raised and stowed positions, as described below.  
         [0032]     A second roof bow  100  extends transversely across vehicle  22  and is fixedly attached to straight-folding portion  46   b  of front roof rail  46 . Similarly, a third roof bow  102  extends transversely across vehicle  22  and is fixedly attached to rear roof rails  58 . If desired, second and/or third roof bows  100 ,  102  can be formed or cast integrally with straight-folding portions and rear roof rails  46   b,    58 , respectively, if desired. Roof cover  36  is loosely attached to second and third roof bows  100 ,  102 .  
         [0033]     Referring now to  FIGS. 2A-2C  and  4 A- 4 B, details of in-folding linkage assembly  52  are shown. In-folding linkage assembly  52  includes a first in-folding link  104  having one end pivotally connected to straight-folding portion  46   b  of front roof rail  46  at pivot  106  and an opposite end pivotally connected to an end of a second in-folding link  108  at pivot  110 . The opposite end of second in-folding link  108  is pivotally connected to in-folding portion  46   a  of front roof rail  46  at pivot  112 . In-folding linkage assembly  52  thereby forms a four-bar linkage assembly including straight-folding portion  46   b,  in-folding portion  46   a,  second in-folding link  108  and first in-folding link  104  and is defined by pivots  50 ,  112 ,  110  and  106 . In-folding linkage assembly  52  controls the relative movement of in-folding portion  46   a  relative to straight-folding portion  46   b  during the extension and retraction of top stack mechanism  34 , as described in more detail below.  
         [0034]     A coupling link  114  interconnects in-folding linkage assembly  52  with intermediate linkage assembly  57 . One end of coupling link  114  is connected to an end of first link  80  of intermediate linkage assembly  57  adjacent pivot  82  with a ball joint  116 . The opposite end of coupling link  114  is coupled to in-folding linkage assembly  52  adjacent pivot  110  with a ball joint  118 . Ball joints  116 ,  118  allow three degrees of movement of coupling link  114  relative to first link  80  and in-folding linkage assembly  52 . Coupling link  114  transfers the motion of intermediate linkage assembly  57  to in-folding linkage assembly  52  to control and coordinate the extension and retraction of top stack mechanism  34 , as described in more detail below.  
         [0035]     Referring now to  FIGS. 2A-2C  and  FIG. 5 , details of synchronizing linkage assembly  48  are shown. Each synchronizing linkage assembly  48  includes a first synchronizing link  120  having one end pivotally connected to in-folding portion  46   a  of front roof rail  46  at pivot  122  and an opposite end pivotally connected to number one roof bow  44  at pivot  124 . One end of a second synchronizing link  126  is pivotally connected to an intermediate portion of first synchronizing link  120  at pivot  128  while an opposite end of second synchronizing link  126  is pivotally connected to one end of a synchronizing crank  130  at pivot  132 . An opposite end of synchronizing crank  130  is pivotally connected to the second synchronizing link  126  on the other side of top stack mechanism  34 . A central portion of synchronizing crank  130  is pivotally connected to number one roof bow  44  at pivot  134 . Synchronizing linkage assemblies  48  keep the two sides of top stack mechanism  34  in sync with one another as top stack mechanism  34  moves between the raised and retracted positions. Synchronizing linkage assemblies  48  also prevent cross car drift of top stack mechanism  34  during movement between the raised and stowed positions.  
         [0036]     In operation, convertible roof  20  is movable between the raised position, shown in  FIG. 1 , through intermediate positions, such as those shown in  FIGS. 2A-2C , to a fully stowed position, as shown in  FIGS. 3A and 3B . To move convertible roof  20  from the raised position to the stowed position, number one roof bow  44  is unlatched from the front header of vehicle  22 . Actuators  71  are commanded to retract and pull on balance links  66 , causing balance links  66  to rotate rearwardly. As balance links  66  rotate rearwardly, rear roof rails  58  pivot rearwardly about pivots  64  while center roof rails  54  pivot forwardly relative to rear roof rails  58  about pivots  60 . Rearward rotation of rear roof rails  58  cause control links  72  to pull intermediate linkage assemblies  57  rearwardly.  
         [0037]     The rearward pulling of intermediate linkage assemblies  57  causes pivots  76  to move rearwardly and second links  84  to rotate rearwardly relative to center roof rails  54  about pivots  86 . First links  80  pull on straight-folding portions  46   b,  causing rearward rotation relative to center roof rails  54  about pivots  56 . The movement of first links  80  pull coupling links  114  rearwardly relative to straight-folding portions  46   b.  Coupling links  114  pull in-folding linkage assemblies  52  rearwardly, causing in-folding portions  46   a  of front roof rails  46  to pivot inwardly about pivots  50  toward center line  40  of vehicle  22 .  
         [0038]     As in-folding portions  46   a  of front roof rails  46  pivot inwardly, the ends of first synchronizing links  120  attached to in-folding portions  46   a  also rotate inwardly about pivots  124  and second synchronizing links  126  approach one another and cause synchronizing crank  130  to rotate clockwise in the orientation shown in  FIG. 2A . The movement of first and second synchronizing links  120 ,  126  allow synchronizing linkage assemblies  48  to constrain the in-folding of in-folding portions  46   a  of front roof rail  46  and draw number one roof bow  44  rearwardly. The constraining of the in-folding of in-folding portions  46   a  prevents top stack mechanism  34  from drifting side-to-side during the retraction and extension processes, thereby enabling smooth and aesthetically pleasing operation of convertible roof  20 . Actuators  71  continue to retract until top stack mechanism  34  reaches its stowed position, as shown in  FIGS. 3A and 3B , wherein convertible roof  20  is disposed within stowage compartment  30 .  
         [0039]     To move convertible roof  20  from its stowed position to its raised position, actuators  71  are commanded to extend in length and push on balance links  66  causing forward rotation about pivots  68 . The forward rotation is transferred to center roof rails  54  and rear roof rails  58 . As convertible roof  20  rises, rear roof rails  58  rotate forwardly about pivots  64  and center roof rails  54  rotate rearwardly relative to rear roof rails  58  about pivots  60 . Control links  72  push intermediate linkage assemblies  57  forwardly, thereby causing straight-folding portions  46   b  of front roof rails  46  to rotate forwardly relative to center roof rails  54  about pivots  56 . This action causes pivots  76  to approach pivots  56 . Coupling links  114  push forwardly on in-folding linkage assemblies  52 . In-folding portions  46   a  of front roof rails  46  rotate outwardly relative to straight-folding portions  46   b  about pivots  50 .  
         [0040]     First synchronizing links  120  pivot about pivots  122 ,  124  and approach in-folding portions  46   a  as top stack mechanism  34  approaches the fully raised position. Second synchronizing links  126  move away from one another and rotate synchronizing crank  130  counterclockwise in the orientation depicted in FIG.  2 A. Actuators  71  continue to expand in length until top stack mechanism  34  has been moved to the fully raised position, as shown in  FIG. 1 . Number one roof bow  44  can then be latched to the front header of vehicle  22  to secure top stack mechanism  34  in the fully raised position.  
         [0041]     While various aspects of convertible roof  20  and top stack mechanism  34  have been disclosed, it will be appreciated that many other variations may be employed without departing from the scope of the present invention. For example, the in-folding linkage assemblies  52  and intermediate linkage assemblies  57  can be more than four-bar linkages. Actuators  71  can be other than fluidic actuators, such as solenoids and rotary actuators among others. Furthermore, top stack mechanism  34  may be manually operated. Moreover, while pivots  64  and pivot axis  65  are shown as being fixed, it should be understood that pivots  64  and pivot axis  65  can move, such as when in a slot or when brackets  62  move, while still maintaining pivot axis  65  substantially perpendicular to center line  40 . The exact location of the various pivots of top stack mechanism  34  can vary from the locations shown in drawings and still be within the scope of the present invention. Furthermore, the specific configurations and orientations of the various linkages and roof rails can have shapes that differ from those shown and still be within the scope of the present invention. Additionally, the roof can be stowed in the rear seating area of the passenger compartment.  
         [0042]     Referring now to  FIGS. 6-11C , the preferred embodiment of an in-folding convertible roof  220  according to the principles of the present invention is shown. Convertible roof  220  is employed on an automotive vehicle  222  having a passenger compartment  224  with front and rear passenger seating areas  226 ,  228  accessible by front and rear doors  229   a,    229   b  and a generally U-shaped bootwell or stowage compartment  230 . Stowage compartment  230  is positioned aft of passenger compartment  224  with quarter trim portions  232  extending along a portion of sides of passenger compartment  224 . Convertible roof  220  utilizes a folding or top stack mechanism  234  and a roof cover  236  (shown in  FIG. 7  only) and is operable between a fully raised position, as shown in  FIG. 6 , through intermediate positions, such as that shown in  FIG. 7 , to a fully stowed position, as shown in  FIGS. 8A and 8B . Roof cover  236  is made from a pliable material, such as vinyl, canvas or a polyester fabric. If desired, roof cover  236  can include a hard or rigid portion that, optionally, can be covered by the same material that comprises the soft portion of the cover to give a uniform appearance. A backlight (not shown) is attached to roof cover  230  and is not pivotally coupled to top stack mechanism  234 . The backlight can be made of either a rigid material, such as glass, or a pliable transparent material, such as vinyl.  
         [0043]     In  FIGS. 6-11C , convertible roof  220  and top stack mechanism  234  are shown symmetrical about a longitudinal, fore-and-aft center line  240  (shown in  FIG. 8B ) of vehicle  222 . Center line  240 , thus, also serves as a longitudinal center line for convertible roof  220  and top stack mechanism  234 . Top stack mechanism  234  includes right and left roof linkages on the respective right and left sides of vehicle  222 . For brevity, at times only one side of top stack mechanism  234  and convertible roof  220  may be shown and/or discussed. However, it should be understood that the other side linkages are also provided as part of top stack mechanism  234  and convertible roof  220  and are mirrored images of the side depicted and/or discussed. Also, when using the terms “fore” and “aft,” “front” and “back,” and “forward” and “rearward” in describing the movement and components of top stack mechanism  234  and convertible roof  220 , such reference refers to the orientation of the components when top stack mechanism  234  and convertible roof  220  are in the fully raised position.  
         [0044]     Top stack mechanism  234  includes a number one roof bow  244  that extends transversely across vehicle  222  and is disposed above the front windshield header when in the fully raised position, as shown in  FIG. 6 . Roof cover  236  is attached to number one roof bow  244 . Number one roof bow  244  is coupled to a pair of segmented front roof rails  246  by synchronizing linkage assemblies  248 , described in more detail below.  
         [0045]     Segmented front roof rails  246  include an in-folding portion  246   a  and a straight-folding portion  246   b.  In-folding and straight-folding portions  246   a,    246   b  are pivotally connected together at pivots  250  and are interconnected by in-folding linkage assemblies  252 , described in more detail below. A number two roof bow  253  is fixedly attached to a front portion of straight-folding portions  246   b.  Number two roof bow  253  includes a U-shaped extension  253   a  (shown in  FIG. 6  only) that extends forwardly from the main section. Extension  253   a  supports roof cover  236  and prevents roof cover  236  from interfering with the operation of synchronizing linkage assemblies  248  during the retraction and extension of convertible roof  220 . Straight-folding portions  246   b  are pivotally connected to front portions of a pair of center roof rails  254  at pivots  256  and are interconnected with intermediate linkage assemblies  257 , described in more detail below. A number three roof bow  260  extends transversely across vehicle  220  and is pivotally connected to intermediate portions of center roof rails  254  at pivots  262 . Number three roof bow  260  is loosely attached to roof cover  236  and moves with the movement of roof cover  236 .  
         [0046]     Rear portions of center roof rails  254  are pivotally connected to front or top portions of rear roof rails  258  at pivots  264 . The opposite ends of rear roof rails  258  are pivotally connected to fixed brackets  266  at pivots  268 . Pivots  268  are aligned along a pivot axis  269  which is generally perpendicular to longitudinal center line  240 . Rear roof rails  258  rotate about pivots  268  and pivot axis  269  during extension and retraction of top stack mechanism  234 , as describe below. Brackets  266  are fixed to vehicle  222  within stowage compartment  230 .  
         [0047]     One end of a balance link  270  is pivotally coupled to bracket  266  at pivot  272  while an opposite end of balance link  270  is pivotally coupled to a rear portion of center roof rail  254  at pivot  274 . The interconnection between center roof rail  254 , rear roof rail  258 , bracket  266  and balance link  270  forms a rear four-bar linkage assembly  275  defined by pivots  264 ,  268 ,  272  and  274 . A number four roof bow  276  extends transversely across vehicle  220  and is fixedly attached to a front or top portion of balance link  270 . An actuator  278  is attached to bracket  266  and coupled to balance link  270 . Actuator  278  includes an electric motor  280  and a gear box  282 . A linkage assembly  284  interconnects gear box  282  with balance link  270  thereby enabling actuator  278  to cause balance link  270  to rotate about pivot  272 . Rotation of balance link  270  about pivot  272  causes convertible roof  220  to move between the raised and stowed positions, as described in more detail below.  
         [0048]     A number five roof bow  286  extends transversely across vehicle  222  and is pivotally coupled to brackets  266  at pivots  288 . Number five roof bow  286  is attached to roof cover  236  and moves with the movement of roof cover  236 . A number six or rearmost roof bow  292  extends transversely across vehicle  222  and is pivotally coupled to brackets  266  with connecting links  294 . One end of a connecting link  294  is pivotally coupled to an end of number six roof bow  292  while the opposite end of connecting link  294  is pivotally coupled to bracket  266 . An actuator  296 , in this case in the form of a fluidic actuator, is pivotally coupled to bracket  266  and to number six roof bow  292 . Extension of actuator  296  causes number six roof bow  292  to rotate upwardly and forwardly and retraction of actuator  296  causes number six roof bow  292  to move downwardly and rearwardly, as described in more detail below. Number six roof bow  292  is also coupled to linkage assembly  284  to allow actuator  278  to move number six roof bow  292  into and out of stowage compartment  230 . A rear portion of roof cover  236  is attached to number six roof bow  292 . Number six roof bow  292  rests on a moveable tonneau cover  298  of vehicle  222  when convertible roof  220  is in the raised position, as shown in  FIG. 6 .  
         [0049]     Rear linkage assembly  275  and intermediate linkage assembly  257  are interconnected by a control link  300 . One end of control link  300  is pivotally connected to an end of balance link  270  at pivot  302 . An opposite end of control link  300  is pivotally connected to intermediate linkage assembly  257  at pivot  304 . Control link  300  causes intermediate linkage assembly  257  to rotate front roof rails  246  relative to center roof rails  254  during extension and retraction of top stack mechanism  234 , as described in more detail below.  
         [0050]     Intermediate linkage assembly  257 , as best seen in  FIGS. 9A and 9B , interconnects straight-folding portion  246   b  of front roof rail  246  with center roof rail  254 . Intermediate linkage assembly  257  includes a straight-folding linkage assembly  308  and an in-folding control linkage assembly  310 . Straight-folding linkage assembly  308  includes a first link  312  having one end pivotally coupled to a front portion of center roof rail  254  at pivot  314  and a second end pivotally coupled to a second link  316  at pivot  318 . The end of control link  300  is pivotally connected to an intermediate portion of first link  312  at pivot  304 . The opposite end of second link  316  is pivotally connected to a rear portion of straight-folding portion  246   b  of front roof rail  246  at pivot  320 . Straight-folding linkage assembly  308  thereby forms a four-bar linkage assembly including straight-folding portion  246   b,  center roof rail  254 , first link  312  and second link  316  and is defined by pivots  256 ,  314 ,  318  and  320 . Straight-folding linkage assembly  308  controls the movement of front roof rail  246  relative to center roof rail  254  during movement of top stack mechanism  234  between the raised and stowed positions, as described below.  
         [0051]     In-folding control linkage assembly  310  includes a first link  322  having one end pivotally connected to a front portion of center roof rail  254  at pivot  324  and an opposite end pivotally connected to an end of a second link  326  at pivot  328 . An intermediate portion of second link  326  is pivotally connected to a rear portion of straight-folding portion  246   b  of front roof rail  246  at pivot  320  (which is also shared with link  316 ). An opposite end of second link  326  is coupled to a coupling link  330  at ball joint  332 . Coupling link  330  is also coupled to in-folding linkage assembly  252  and interconnects in-folding linkage assembly  252  with in-folding control linkage assembly  310 , as described in more detail below. In-folding control linkage assembly  310  thereby forms a four-bar linkage assembly including straight-folding portion  246   b,  center roof rail  254 , first link  322  and second link  326  and is defined by pivots  256 ,  324 ,  328  and  320 . In-folding control linkage assembly  310  is driven by movement of straight-folding portion  246   b  relative to center roof rail  254 . The movement of straight-folding portion  246   b  relative to center roof rail  254  is controlled by straight-folding linkage assembly  308 . Thus, movement of in-folding control linkage assembly  310  is driven by the movement of straight-folding linkage assembly  308 , as described in more detail below.  
         [0052]     Referring now to  FIGS. 9A, 9B  and  10 , details of in-folding linkage assembly  252  are shown. In-folding linkage assembly  252  includes a first in-folding link  340  having one end pivotally connected to straight-folding portion  246   b  of front roof rail  246  at pivot  342  and an opposite end pivotally connected to an end of a second in-folding link  344  at pivot  346 . The opposite end of second in-folding link  344  is pivotally connected to in-folding portion  246   a  of front roof rail  246  at pivot  348 . In-folding linkage assembly  252  thereby forms a four-bar linkage assembly including straight-folding portion  246   b,  in-folding portion  246   a,  second in-folding link  344  and first in-folding link  340  and is defined by pivots  250 ,  348 ,  346  and  342 . In-folding linkage assembly  252  controls the movement of in-folding portion  246   a  relative to straight-folding portion  246   b  during the extension and retraction of top stack mechanism  234 , as described in more detail below. In-folding linkage assembly  252  is driven by movement of coupling link  330 . It should be noted that in-folding linkage assembly  252  operates in a plane that is perpendicular to the plane that intermediate linkage assembly  257  operates in. That is, when viewed in the orientation shown in  FIG. 6 , in-folding linkage assembly  252  operates in a generally horizontal plane while intermediate linkage assemblies  257  (including straight-folding linkage assembly  308  and in-fold control linkage assembly  310 ) operate in a generally vertical plane.  
         [0053]     Coupling link  330  interconnects in-folding linkage assembly  252  with in-folding control linkage assembly  310 . One end of coupling link  330  is connected to an end of link  326  at ball joint  332  while an opposite end of coupling link  330  is connected to an intermediate portion of first in-fold link  340  at ball joint  350 . Ball joints  332 ,  350  allow three degrees of movement of coupling link  330  relative to links  326  and  340  and accommodates the differing planar movements. Coupling link  330  transfers the motion of in-folding control linkage assembly  310  to in-folding linkage assembly  252  to control and coordinate the extension and retraction of top stack mechanism  234 , as described in more detail below.  
         [0054]     Referring now to  FIGS. 7 and 10 , details of synchronizing linkage assembly  248  are shown. Synchronizing linkage assembly  248  includes right and left links  356 ,  358 , that are disposed along the respective right and left sides of top stack mechanism  234 , and a synchronizing link  360  that interconnects right and left links  356 ,  358 . One end of right link  356  is pivotally connected to an inwardly extending extension on the right side in-folding portion  246   a  of front roof rail  246  at pivot  362  while an opposite end of right link  356  is pivotally connected to a right side portion of number one roof bow  244  at pivot  364 . One end of left link  358  is pivotally connected to an inwardly extending extension on the left side in-folding portion  246   a  of front roof rail  246  at pivot  366  while an intermediate portion (near the opposite end) of left link  358  is pivotally coupled to the left side portion of number one roof bow  244  at pivot  368 . Pivots  364  and  368  on number one roof bow are generally aligned with one another. That is, a line connecting pivots  364 ,  368  is generally perpendicular to the fore-aft center line  240 . One end of synchronizing link  360  is pivotally connected to an intermediate portion of right link  356  at pivot  370  slightly rearward of pivot  364 , while an opposite end of synchronizing link  360  is pivotally connected to the end of left link  358  at pivot  372  forward of pivot  368 . With one end of the synchronizing link  360  being pivotally coupled to right link  356  rearwardly of pivot  364  while the opposite end of synchronizing link  360  is pivotally coupled to left link  358  forward of pivot  368 , synchronizing link  360  operates to synchronize the movement of the left and right in-folding portions  246   a  of front roof rail  246 . That is, synchronizing link  360  limits the degrees of freedom of number one roof bow  244  relative to in-folding portions  246   a  of front roof rails  246  and prevents cross-car drift of top stack mechanism  234  during movement between the raised and stowed positions.  
         [0055]     To reduce some of the stress at pivots  362 ,  364 ,  366  and  368 , slotted connections with pins that ride therein are provided. Specifically, right and left links  356 ,  358  each have a pin  374  that rides within slots  376  on the respective right and left in-folding portions  246   a.  Similarly, right and left links  356 ,  358  also each have a pin  378  that rides within slots  380  on the respective right and left sides of number one roof bow  244 . Engagement between pins  374 ,  378  and slots  376 ,  380  provides additional support for right and left links  356 ,  358 , number one roof bow  244  and the right and left in-folding portions  246   a.  The engagement between these slots and the pins does not affect the kinematics of the operation of synchronizing linkage assembly  248 .  
         [0056]     Referring now to  FIGS. 11A-11C , simplified details of a dampening system  390  used with convertible roof  220  are shown. Dampening system  390  is located within brackets  266  and is operable to dampen the motion of top stack mechanism  234  at various times during the extending and retracting of convertible roof  220 , as described in more detail below. The views depicted in  FIGS. 11A-11C  are simplified and a majority of bracket  266  and the other components therein or attached thereto are removed for ease of illustration and explanation. Dampening system  390  includes a damper  392  that dampens some movements of top stack mechanism  234  while allowing unimpeded (undampened) movement of top stack mechanism  234  during other movements. Damper  392  includes a cylindrical housing  394  with an extendable rod  396  extending therefrom. A piston  397  is attached to rod  396  inside cylindrical housing  394 . A fluid, in this case hydraulic fluid, is also contained within housing  394 . The hydraulic fluid dampens the movement of rod  396  (via the piston) relative to housing  394 . The movement of rod  396  is dampened only in one direction. That is, rod  396  is relatively free to be moved into housing  394  while being restrained or dampened when being moved outwardly from housing  394 . Thus, movement of top stack mechanism  234  that causes damper  392  to shorten in length is not dampened while movement of top stack mechanism  234  that causes damper  392  to be elongated is dampened, as described in more detail below. A suitable damper  392  is a model MB-22 hydraulic damper available from Ace Controls Inc. of Farmington Hills, Mich.  
         [0057]     One end of damper  392  is pivotally connected to bracket  266  at pivot  398  while an opposite end of damper  392  is pivotally connected to a bottom extension  400  of rear roof rail  258  at pivot  402 . The orientation of pivot  402  relative to pivot  268  (about which rear roof rails  258  rotate) causes damper  392  to be both shortened and elongated during the movement of top stack mechanism  234  between the raised and stowed positions. As shown in  FIG. 11A , when convertible roof  220  and top stack mechanism  234  are in the fully stowed position, pivot  402  is forward of pivot  268 . As top stack mechanism  234  moves from the stowed position toward the raised position (rear roof rail  258  rotating counter-clockwise in the views of  FIGS. 11A-11C ), rod  396  will be pushed into cylindrical housing  394  and damper  392  will offer little or no resistance to this motion. Rod  396  will continue to be pushed into housing  394  until an on-center position occurs, as shown in  FIG. 11B , wherein pivots  398 ,  402  and  268  are all aligned with one another. Further movement of convertible roof  220  and top stack mechanism  234  toward the raised position causes damper  392  to move away from the on-center position and pull rod  396  out from housing  394 . The pulling of rod  396  out from housing  394  is dampened by the engagement between piston  397  and the hydraulic fluid therein. Thus, during continued motion of top stack mechanism  234  toward the raised position (after damper  392  has passed the on-center position), the movement is dampened by the resistance of rod  396  from being pulled from housing  394 . This dampening helps support top stack mechanism  234  and relieves some stress from actuators  278 , linkage assemblies  284  and the other components of top stack mechanism  234 . Furthermore, this dampening helps diminish the force and velocity with which number one roof bow  244  may contact the front header of vehicle  222 . When in the fully raised position, pivot  402  is located below and rearward of pivot  268 , as shown in  FIG. 11C .  
         [0058]     During the movement of convertible roof  220  and top stack mechanism  234  from the raised position ( FIG. 11C ) to the stowed position ( FIG. 11A ), the initial movement of rear roof rail  258  will push rod  396  into housing  394  while damper  392  offers little or no resistance to this movement. This pushing of rod  396  into housing  394  continues until an on-center position is reached, as shown in  FIG. 11B . Continued rearward rotation of rear roof rail  258  about pivot  268  causes damper  392  to pass the on-center position and extension  400  to begin to pull on rod  396 . The movement of rod  396  out of housing  394  is resisted by the engagement between the piston and the hydraulic fluid thereby dampening the continued rearward rotation of rear roof rail  258  toward the stowed position. Damper  392  thereby removes some of the stresses and strains on actuator  278 , linkage assemblies  284  and other components of top stack mechanism  234  during the final phases of movement of top stack mechanism  234  to the stowed position. Additionally, the dampening helps limit the force and velocity of top stack mechanism  234  into stowage compartment  230 .  
         [0059]     In operation, convertible roof  220  is moveable between the raised position, shown in  FIG. 6 , through intermediate positions, such as that shown in  FIG. 7 , to a fully stowed position, as shown in  FIGS. 8A and 8B . To move convertible roof  220  from the raised position to the stowed position, number one roof bow  244  is unlatched from the front header of vehicle  222 . Actuators  296  are commanded to extend thereby pushing number six roof bow  292  upwardly. When number six roof bow  292  has been pushed upwardly a sufficient distance, tonneau cover  298  can then be moved from the closed position to an open position (not shown). Actuators  296  are commanded to retract and pull on number six roof bow  292  causing number six roof bow  292  to return to its nominal position. With tonneau cover  298  in the open position, access to stowage compartment  230  is available and convertible roof  220  can be retracted into stowage compartment  230 . Actuators  278  are commanded to drive linkage assemblies  284  and pull on balance links  270 , causing balance links  270  to rotate rearwardly. As balance links  270  rotate rearwardly, rear roof rails  258  pivot rearwardly about pivots  268  while center roof rails  254  rotate forwardly relative to rear roof rails  258  about pivots  264 . Rearward rotation of balance links  266  also cause control links  300  to pull straight-folding linkage assemblies  308  rearwardly. Movement of linkage assembies  284  also cause number six roof bow  292  to move downwardly and into stowage compartment  230 .  
         [0060]     The rearward pulling on straight-folding linkage assemblies  308  cause links  312  to rotate rearwardly about pivots  314  relative to center roof rails  254 . This movement of links  312  pull on links  316  which in turn cause straight-folding portions  246   b  to rotate rearwardly relative to center roof rails  254  about pivots  256 .  
         [0061]     The rearward rotation of straight-folding portions  246   b  relative to center roof rails  254  cause pivots  328  that interconnect links  322  and  326  of in-folding control linkage assembly  310  to also move rearwardly. This in turn pulls coupling links  330  rearwardly relative to straight-folding portions  246   b.  The rearward movement of coupling links  330  pulls in-folding linkage assemblies  252  rearwardly, causing in-folding portions  246   a  of front roof rails  246  to pivot inwardly about pivots  250  toward center line  240  of vehicle  222 . It should be noted that the rearward movement of in-folding linkage assemblies  252  are in planes that are perpendicular to the planes of the rearward movement of intermediate linkage assemblies  257 .  
         [0062]     As in-folding portions  246   a  of front roof rails  246  pivot inwardly, the ends of right and left links  256 ,  258  that are pivotally connected to in-folding portions  246   a  rotate inwardly about their respective pivots  364 ,  368  on number one roof bow  244 . Due to the offset arrangement of pivots  370 ,  372  that interconnect synchronizing link  360  to right and left links  356 ,  358 , synchronizing link  360  moves toward the left side of top stack mechanism  234 . Synchronizing link  360  constrains the in-folding of in-folding portions  246   a  of front roof rails  246  as number one roof bow  244  is pulled rearwardly. The constraining of the in-folding movement prevents top stack mechanism  234  from drifting side-to-side during the retraction and extension process, thereby enabling smooth and aesthetically pleasing operation of convertible roof  220 .  
         [0063]     During the later portion of the retraction cycle (after dampers  392  go over-center), dampening system  390  via dampers  392  resist the movement of top stack mechanism  234  which dampens and slows the movement of top stack mechanism  234 , as describe above. Actuators  278  continue to cause top stack mechanism  234  to retract into stowage compartment  230  until the stowed position is reached, as shown in  FIGS. 8A and 8B , wherein convertible roof  220  is disposed within stowage compartment  230 . Tonneau cover  298  is then moved back to its closed position covering an entirety or a portion of convertible roof  220  within stowage compartment  230 .  
         [0064]     To move convertible roof  220  from its stowed position to its raised position, tonneau cover  298  is moved from the closed position to the open position and actuators  278  are commanded to cause linkage assemblies  284  to push on balance links  270  causing forward rotation about pivots  272 . The forward rotation is transferred to center roof rails  254  and rear roof rails  258 . Additionally, linkage assemblies  284  cause number six roof bow  292  to move upwardly and out of stowage compartment  230 . As convertible roof  220  extends, rear roof rails  258  rotate forwardly about pivots  268  and center roof rails  254  rotate rearwardly relative to rear roof rails  258  about pivots  264 . Control links  300  push intermediate linkage assemblies  257  forwardly, thereby causing straight-folding portions  246   b  of front roof rails  246  to rotate forwardly relative to center roof rails  254  about pivots  256 . This action causes pivots  304 ,  328  to approach pivots  256 . Coupling links  330  push forwardly on in-folding linkage assemblies  252 . In-folding portions  246   a  of front roof rails  246  rotate outwardly relative to straight-folding portions  246   b  about pivots  250 .  
         [0065]     The outward rotation of in-folding portions  246   a  cause right and left links  356 ,  358  to rotate outwardly about their respective pivots  364 ,  368 . This in turn causes synchronizing link  360  to move toward the right relative to vehicle  222 . Synchronizing link  360  constrains the out-folding of in-folding portions  246   a  of front roof rails  246  as number one roof bow  244  is pushed forwardly. The constraining of the out-folding movement prevents top stack mechanism  234  from drifting side-to-side during the extension cycle, thereby enabling smooth and aesthetically pleasing operation of convertible roof  220 .  
         [0066]     During the later portion of the extension cycle (after dampers  392  go over-center), dampening system  390  via dampers  392  resist the movement of top stack mechanism  234  which dampens and slows the movement of top stack mechanism  234 , as describe above. Additionally, the force with which number one roof bow  244  may contact the front header of vehicle  222  is also reduced. Actuators  278  continue to cause balance links  270  to rotate forwardly until top stack mechanism  234  has been moved to the fully raised position, as shown in  FIG. 1 . Actuators  296  are then commanded to extend and cause the rear portion of number six roof bow  292  to move upwardly and forwardly. When number six roof bow  292  has been moved a sufficient distance, tonneau cover  298  is then moved from the open position to the closed position. Actuators  296  are then commanded to retract and cause number six roof bow  292  to move downwardly and on top of tonneau cover  298  and into its nominal position. Number one roof bow  244  is then latched to the front header of vehicle  222  to secure top stack mechanism  234  in the fully raised position.  
         [0067]     Referring now to  FIG. 12A , a second alternate embodiment of a synchronizing linkage assembly  500  for constraining the in-folding of a convertible roof is shown. The view depicted in  FIG. 12A  is a simplified bottom plan view of the front portion of the in-folding convertible roof system of  FIG. 6  with synchronizing linkage assembles  500  thereon. Each synchronizing linkage assembly  500  includes an in-folding link  502  having one end pivotally connected to an in-folding portion  504  of a front roof rail at pivot  506  while the opposite end is pivotally connected to number one roof bow  508  at pivot  510 . One end of a synchronizing link  512  is pivotally connected to an intermediate portion of in-folding link  502  at pivot  514  while an opposite end is pivotally connected to an end of a synchronizing crank  516  at pivot  518 . An intermediate portion of synchronizing crank  516  is pivotally connected to number one roof bow  508  at pivot  520 . The other end of synchronizing crank  516  is pivotally connected to a slide joint  522  on one end of a synchronizing slider  524 . Synchronizing slider  524  is slidably connected to number one roof bow  508  in a slide channel  526  on number one roof bow  508 . The slide joint  522  on the opposite end of synchronizing slider  524  is connected to an end of a synchronizing crank  516  on the other side of the number one roof bow  508 . Slider  524  can move forwardly and rearwardly relative to number one roof bow  508  within slide channel  526 .  
         [0068]     During retraction of the convertible roof, the front ends of in-folding roof rail portions  504  rotate inwardly and cause the ends of in-folding links  502  attached to pivots  506  to rotate inwardly about pivots  510 . The rotation of in-folding roof rail portions  504  also cause in-folding links  502  to move rearwardly and pull number one roof bow  508  rearwardly. The rotation of in-folding links  502  pushes synchronizing links  512  inwardly which cause synchronizing cranks  516  to rotate about pivots  520  and move pivots  518  rearwardly. The rotation of synchronizing cranks  516  via slide joints  522  push synchronizing slider  524  forwardly relative to number one roof bow  508  within slide channel  526 . The interaction between in-folding links  502 , synchronizing links  512 , synchronizing crank  516  and synchronizing slider  524  constrain the movement of the top stack mechanism and keep the two sides of the top stack mechanism in sync during the retraction cycle. The interaction also prevents cross car drift. During the extension cycle of the top stack mechanism, the interactions are reversed and the movement of the top stack mechanism remains synchronized and constrained. Thus, synchronizing linkage assemblies  500  are operable to synchronize and constrain the movement of the top stack mechanism during retraction and extension cycles.  
         [0069]     Referring now to  FIG. 12B , a third alternate embodiment of a synchronizing linkage assembly  600  for constraining the in-folding of the convertible roof is shown. The view depicted in  FIG. 12B  is a simplified bottom plan view of the front portion of the in-folding convertible roof system of  FIG. 6  with synchronizing linkage assembly  600  thereon. Synchronizing linkage assembly  600  includes right and left side in-folding links  602   a,    602   b  that have one end pivotally connected to in-folding roof rail portions  604  on the respective right and left sides of the top stack mechanism at pivots  605 . The opposite ends of in-folding links  602   a,    602   b  are fixed to respective right and left side pulleys  606   a,    606   b.  Pulleys  606   a,    606   b  are pivotally connected to respective right and left sides of number one roof bow  608  at respective pivots  610   a,    610   b.  One end of first and second cables  612 ,  614  are each fixed to an outer portion (when the top stack mechanism is fully raised) of right pulley  606   a  while the other end of first and second cables  612 ,  614  are each fixed to an outer portion (when the top stack mechanism is fully raised) of left pulley  606   b.  First cable  612  extends around a front portion of right pulley  606   a  across the top stack mechanism and around a rear portion of left pulley  606   b.  In contrast, second cable  614  extends around a rear portion of right pulley  606   a  across the top stack mechanism and around a front portion of left pulley  606   b.  The opposite wrapping of cables  612 ,  614  allows synchronizing linkage assembly  600  to constrain the in-folding of the roof rail during retraction and extension of the top stack mechanism.  
         [0070]     During retraction of the top stack mechanism, the front ends of in-folding roof rail portions  604  rotate inwardly and cause the ends of in-folding links  602   a,    602   b  attached to pivots  605  to rotate inwardly. The rotation of in-folding roof rail portions  604  also cause in-folding links  602   a,    602   b  to move rearwardly and pull number one roof bow  608  rearwardly. The rotation of in-folding links  602   a,    602   b  cause the respective pulleys  606   a,    606   b  to rotate in opposite directions (counter clockwise and clockwise respectively in the view depicted) about pivots  610   a,    610   b.  The opposite rotation of pulleys  606   a,    606   b  maintains the tension in cables  612 ,  614 . Maintaining the tension in cables  612 ,  614  constrains the movement of the top stack mechanism and minimize cross car drift of the top stack mechanism during the retraction cycle. During the extension cycle of the top stack mechanism, the interactions are reversed and tension in cables  612 ,  614  remains the same and constrains the movement of the top stack mechanism. Thus, synchronizing linkage assembly  600  is operable to synchronize and constrain the movement of the top stack mechanism during retraction and extension cycles.  
         [0071]     While various aspect of convertible roof  220  and top stack mechanism  234  have been disclosed, it will be appreciated that many other variations may be employed without departing from the scope of the present invention. For example, while actuators  278  are shown as being an electric motor  280  coupled to a gear box  282 , other types of actuators could be employed. For example, linear actuators, such as fluidically-driven cylinders, can be employed. Furthermore, fluidically-driven rotary actuators could also be employed. Moreover, the use of the in-folding control linkage assembly  310  may be eliminated by configuring link  316  into a desired orientation and attaching control link  330  to second link  316 , providing a desired motion can be translated to coupling link  330  via the movement of straight-folding linkage assembly  308 .  
         [0072]     Additionally, while pivots  268  and pivot axis  269  are shown as being fixed, it should be understood that pivots  268  and pivot axis  269  can move, such as when in a slot or when brackets  266  move, while still maintaining pivot axis  269  substantially perpendicular to center line  240 . The exact location of the various pivots of top stack mechanism  234  can vary from the locations shown in drawings and still be within the scope of the present invention. Furthermore, the specific configurations and orientations of the various linkages and roof rails can have shapes that differ from those shown and still be within the scope of the present invention. Additionally, the roof can be stowed in the rear seating area of the passenger compartment.  
         [0073]     Moreover, while dampening system  390  is shown as using a fluidic damper  392 , it should be appreciated that other types of dampers could be employed. For example, a spring-loaded damper that resists elongation could be employed. Moreover, a curved rack and a biased pinion may also be employed. Furthermore, fluids other than hydraulic fluid could also be used for a fluidic damper. Moreover, the fluidic damper could connect to other components of top stack mechanism  234  to dampen the motion. For example, the damper could be coupled to the balance link or other components. Additionally, it should be appreciated that the dampening system of the present invention could also be employed on convertible roofs that do not include in-folding features and/or are shorter in length. Additionally, the dampening system could also be used on convertible roofs that utilize hard panels or rigid panels in lieu of or in addition to the soft roof cover. Additionally, the dampening system can employ dampers at different locations along the top stack mechanism to dampen different portions of the top stack mechanism and/or include multiple dampers spaced at different locations along the top stack mechanism.  
         [0074]     It should also be appreciated that the in-folding aspects and the synchronizing linkage assemblies utilized in the present invention could be employed on a convertible roof system that utilizes more or less roof rails, such as a bi-fold top stack mechanism with a segmented front roof rail. Furthermore, it should be appreciated that the synchronizing linkage assemblies can take other forms with different shaped components and/or pivot points and/or more or less components.  
         [0075]     Thus, the foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.

Technology Classification (CPC): 1