Abstract:
A vehicle door system including a door being pivotally moved about a first axis and a second axis. In another aspect of the present invention, the system provides a locking device that is slidably engaged to lock the door. Another aspect of the present invention pertains to a pair of adjacent passenger doors that open in opposite directions.

Description:
BACKGROUND &amp; SUMMARY OF THE INVENTION 
     The present invention relates to automotive vehicle door systems and, more particularly, relates to automotive vehicle door systems having a hinge defining a pair of pivot axes. 
     Typically, motor vehicle doors are pivotally coupled to a pillar of a motor vehicle using a hinge, wherein the hinge is rigidly mounted to the vehicle to support the leveraging forces of the vehicle door during articulation. A vertical pivot rod extends through the hinge and defines a single, vertical, pivot axis about which the door rotates during pivotal movement. To open the vehicle door, the door is pivoted about the single pivot axis. However, the pivotal movement of the vehicle door is limited by physical interference that is common between the leading edge of the vehicle door and the vehicle body panel. Thus, it should be appreciated that this conventional hinge may not maximize the opening to the passenger compartment, thereby hampering ingress and egress. Moreover, the use of this conventional hinge may lead to interference between body side moldings on the vehicle door and the forward body panel, if physical stops are not employed. 
     In some known four-door vehicles, these conventional door systems, which pivot about a single pivot axis, have been used such that the front doors swing in a first direction while the rear doors swing in an opposite direction. For purposes of this application, the term front-access rear doors will mean doors having a hinge on the rearward side of the door such that they open in a mirror direction relative to the front doors. When designing a single pivot door system to be used in this configuration, it is commonly necessary to make the doors thinner to eliminate physical interference between the locking edges of the front and rear doors. This thinning of the doors may not afford maximum packaging allowances for such mechanisms as power windows, door locks, and/or side impact protection. 
     Accordingly, there exists a need in the relevant art to provide an improved vehicle door system capable of maximizing the opening to the passenger compartment. Additionally, there exists a need in the relevant art to provide an improved vehicle door system capable of maintaining an acceptable vehicle door thickness for packaging of vehicle and safety components. Furthermore, there exists a need in the relevant art to provide an improved vehicle door system capable of eliminating a conventional vehicle B pillar (center pillar) and/or capable of receiving a power drive mechanism for driving the door. 
     In accordance with the broad teachings of the present invention, a vehicle door system having an advantageous construction and method of operation is provided which includes a door and a hinge having a first end pivotally connectable to the vehicle for rotation about a first pivot. In another aspect of the present invention, the hinge further includes a second end pivotally connected to the door for rotation about a second pivot. Yet another aspect of the present invention provides a first pivot hinge being parallel to and offset from a second hinge pivot. 
     According to alternative embodiments of the present invention, the door system may include a locking extension extending from the door and a receiver device mounted to the vehicle, whereby during a locking movement of the door, the locking extension slidably engages with the receiver device. In a further aspect of the present invention, this sliding engagement is generally parallel to a longitudinal axis of the vehicle (i.e. parallel to the plane of the door). An additional aspect of the present invention uses the door system that may include a biasing device for preventing rotation about the second pivot axis after a predetermined initial rotational movement. Another aspect of the present invention pertains to a pair of adjacent passenger doors that open in opposite directions. 
     Unlike known designs, the elimination of the vehicle B pillar (center pillar) extending between the doors may provide additional packaging and aesthetic benefits. Still further, it may be preferable to incorporate a power drive mechanism to facilitate automatic opening and closing of the vehicle doors. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a vehicle employing the preferred automotive vehicle door system of the present invention; 
     FIG. 2 is an enlarged perspective view of the automotive vehicle door system shown in FIG. 1; 
     FIG. 3 is a side elevational view of the automotive vehicle door system in a substantially opened position; 
     FIG. 4 is a perspective view, with portions represented schematically, of a front door system; 
     FIG. 5 is a perspective view of the front door system taken from an inboard position looking forward; 
     FIG. 6 is a perspective view of a sector gear assembly employed in the preferred embodiment automotive vehicle door system; 
     FIG. 7 is a perspective view, with portions represented schematically, of a rear door system; 
     FIG. 8 is a perspective view of the rear door system taken from an outboard position looking rearward; 
     FIG. 9 is a diagrammatic plan view of a locking mechanism employed in the preferred embodiment automotive vehicle door system, disposed in a closed and locked position; 
     FIG. 10 is a diagrammatic plan view of the locking mechanism employed in the preferred embodiment automotive vehicle door system, disposed in a first intermediate position; 
     FIG. 11 is a diagrammatic plan view of the locking mechanism employed in the preferred embodiment automotive vehicle door system, disposed in a second intermediate position following disengagement of the locking mechanism; 
     FIG. 12 is a diagrammatic plan view of the automotive vehicle door system in a closed and locked position; 
     FIG. 13 is a diagrammatic plan view of the automotive vehicle door system illustrating a first opening motion; 
     FIG. 14 is a diagrammatic plan view of the automotive vehicle door system illustrating the sliding disengagement of the locking mechanism; 
     FIG. 15 is a diagrammatic plan view of the automotive vehicle door system following disengagement of the locking mechanism; and 
     FIG. 16 is a diagrammatic plan view of the automotive vehicle door system in a fully opened and unlocked position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     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. For example, the present invention may find utility in any door closure for a vehicle, including side doors, rear doors, and the like. In the following description of the preferred embodiment, the present invention will be described in connection with a rear-access front door and a front-access rear door, wherein each door is power actuated. It should be understood that the teaching of the present invention may be applied to applications others than the aforementioned. 
     Referring to FIGS. 1-3, the preferred embodiment of the automotive vehicle door system of the present invention is used in a vehicle  10  having a front door system  12  and a rear door system  14  mounted thereto. As will be described below, front door system  12  includes a front door  16 , a front hinge unit  18 , a locking device  20 , and an automatic power-actuating device  22  (shown schematically). Similarly, rear door system  14  includes a rear door  24 , a rear hinge unit  26 , a locking device  28 , and an automatic power-actuating device  30  (shown schematically). It should be understood that vehicle  10  further includes an additional front door system that is a mirror-image of front door system  12  and an additional rear door system that is a mirror-image of rear door system  14  disposed on the passenger&#39;s side of the vehicle. However, in the interest of brevity, only front door system  12  and rear door system  14  on the driver&#39;s left side (not in all countries) of the vehicle will be described in detail. 
     As best seen in FIGS. 4 and 5, front door system  12  includes front door  16 , front hinge unit  18 , and power-actuating device  22 . Front hinge unit  18  includes a pair of vehicle mounting brackets  32  fixedly mounted to vehicle  10  within a door jamb section  34  of an A-pillar using threaded fasteners, welding, etc. Each of the pair of vehicle mounting brackets  32  includes apertures  36  (only two shown) for receiving a first generally vertically-disposed mounting rod  38 . Similarly, front hinge unit  18  includes a pair of door mounting brackets  40  fixedly mounted to front door  16  within door jam section  34  using fasteners, welding, etc. Each of the pair of door mounting brackets  40  includes apertures  42  (only two shown) for receiving a second generally vertically-disposed mounting rod  44 . Front hinge unit  18  still further includes a generally U-shaped main member  46  pivotally coupled at one end to vehicle mounting brackets  32  and at the other end to door mounting brackets  40 . Specifically, U-shaped main member  46  includes an upper portion  48 , a lower portion  50 , and a vertically oriented portion  52  interconnecting upper portion  48  and lower portion  50 . Apertures (not shown) are disposed at each end of upper portion  48  and lower portion  50  of U-shaped main member  46  for receiving first mounting rod  38  and second mounting rod  44 . That 
     Still referring to FIGS. 4 and 5, front hinge unit  18  further includes a pneumatic actuator assembly  54  generally disposed within front door  16 . Pneumatic actuator assembly  54  includes a pneumatic actuator  56 , a bell crank  58 , and an interconnecting linkage  60 . Pneumatic actuator  56  is of a piston and cylinder type. Pneumatic actuator  56  is disposed generally horizontally within front door  16  such that a first end of pneumatic actuator  56  is coupled to front door  16  at pivot  62  (FIG. 4) and a second end of pneumatic actuator  56  is coupled to bell crank  58  at pivot  64  (FIG.  5 ). It should be understood that pneumatic actuator  56  may be any actuator capable of providing a biasing force, such as a motor drive, rubber grommet, spring device, etc. Bell crank  58  is pivotally mounted within front door  16  to a bell crank bracket  66  such that bell crank  58  pivots about a central pivot  68 . In the interest of packaging, bell crank  58  is preferably disposed in a generally vertical plane. However, in other figures bell crank  58  may be shown generally horizontally to aid in the description and understanding of the present disclosure. 
     As best seen in FIG. 5, bell crank  58  is further pivotally coupled to interconnecting linkage  60  at pivot  70 . Lastly, interconnecting linkage  60  is pivotally coupled to vertically oriented portion  52  of U-shaped main member  46  at tab  72 . Briefly, in operation, pneumatic actuator  56  exerts an outward force in the direction of arrow C, which causes bell crank  58  to pivot about central pivot  68  such that interconnecting linkage  60  is drawn in the direction of arrow D. This motion urges front door  16  towards U-shaped main member  46  to limit rotation of front door  16  about pivot axis B after a predetermined amount of rotation. This motion will be described further below. It should be appreciated that pneumatic actuator  56  and bell crank  58  may be oriented in any direction that is conducive to packaging so long as the door is urged or biased toward the main member. Moreover, as mentioned above, pneumatic actuator  56  may be any one of a number of actuating/biasing members and, thus, could exert only a compression force. 
     As best seen schematically in FIG. 4, power-actuating device  22  of front door system  12  includes an electric motor  74 , a drive cable  76 , a sector gear  78 , a drive linkage  80 , a bell crank  82 , and a driven linkage  84 . Electric motor  74  is preferably a compact DC motor commonly used in power-actuated vehicle systems. Electric motor  74  may be positioned at any location generally near sector gear  78 , which is convenient for packaging purposes. Electric motor  74  is operably coupled to sector gear  78  through drive cable  76 . Drive cable  76  may be any cable capable of transmitting a rotary driving motion therethrough, such as speedometer-type drive cables. Drive cable  76  is preferably laterally flexible to enable simple and convenient routing through vehicle  10 . Drive cable  76  is operably coupled to sector gear  78  to transmit such rotary force. Sector gear  78  includes an upper plate member  86  and a lower plate member  88 . Lower plate member  88  is rotatably driven by drive cable  76 . Similarly, drive linkage  80  is pivotally coupled to upper plate member  86  at pivot  90 . Upper plate member  86  and lower plate member  88  rotate together about a common axis such that rotational movement of drive cable  76  rotates lower plate member  88  and upper plate member  86 . Such rotational movement of upper plate member  86  linearly drives drive linkage  80 . Drive linkage  80  is pivotally coupled to bell crank  82  at pivot  92 . Similarly, driven linkage  84  is pivotally coupled to bell crank  82  at pivot  94 . As best seen in FIG. 4, bell crank  82  is pivotally mounted to vehicle  10  at pivot  96 . Unlike bell crank  58 , which pivots about central pivot  68  to produce an output that is generally in the opposite direction as the input, pivot  96  is positioned at an end of bell crank  82 . Therefore, bell crank  82  produces an output that is generally in the same direction as the input; however, the output has a higher magnitude due to the amplifying effect of bell crank  82 . Alternatively, bell crank  82  may be eliminated provided sufficient force is available to actuate the vehicle door. 
     As best seen in FIG. 5, driven linkage  84  is pivotally coupled to upper portion  48  of U-shaped main member  46  at tab  98 . Briefly, in operation, motor  74  rotatably drives drive cable  76 . Drive cable  76  transmits this rotational force to sector gear  78  and drive linkage  80 . Drive linkage  80  linearly drives bell crank  82  about pivot  96 , which linearly drives driven linkage  84 , thereby rotating U-shaped main member  46  about pivot axis A. 
     Referring to FIG. 6, sect or gear  78  further includes an electromagnetic solenoid  100 , which selectively actuates a latch mechanism  102 . Latch mechanism  102  includes a tab and notch  104  or other retaining means, such as gear teeth, etc. Latch mechanism  102  is shown mounted on upper plate member  86  of sector gear  78  and notch  104  is shown formed in lower plate member  88  of sector gear  78 . Typically, the tab of latch mechanism  102  is retained within notch  104 , thereby preventing relative motion between upper plate member  86  and lower plate member  88 . This enables rotational input force from drive cable  76  to drive lower plate member  88  and upper plate member  86  simultaneously, thereby driving drive linkage  80 . If a user prefers to open front door  16  manually, a controller  106  detects the depression of a door handle (not shown) through a switch that sends a signal to controller  106 , controller  106  may then actuate solenoid  100  and, thus, release latch mechanism  102  from notch  104 . Controller  106  is preferably a microprocessor capable of independently controlling front door system  12  and rear door system  14  in response to an input signal. The above arrangement enables upper plate member  86  and lower plate member  88  to rotate independently. It is anticipated that electronic controller  106 , such as a microprocessor, may be programmed so as to enable manual opening, while having the ability to re-engage the latch mechanism with the notch to facilitate automatic closing. It is further anticipated that controller  106  will provide control for front power-actuating device  22  and rear power-actuating device  30 . 
     Turning now to FIGS. 7 and 8, rear door system  14  includes rear door  24 , rear hinge unit  26 , and power-actuating device  30 . Rear hinge unit  26  includes a vehicle mounting bracket  108  fixedly mounted to vehicle  10  within a door jam section  110  of a C-pillar or quarter panel using conventional means, such as fasteners, welding, etc. Vehicle mounting bracket  108  includes apertures  112  (only one shown) for receiving a third generally vertically-disposed mounting rod  114 . Similarly, rear hinge unit  26  includes a door mounting bracket  116  fixedly mounted to rear door  24  within door jam section  110  using conventional means, such as fasteners, welding, etc. Door mounting bracket  116  includes apertures  118  (only one shown) for receiving a fourth generally vertically-disposed mounting rod  120 . Rear hinge unit  26  still further includes a generally elongated main member  122  pivotally coupled at one end to vehicle mounting bracket  108  and at the other end to door mounting bracket  116 . Apertures (not shown) are disposed at each end of elongated main member  122  for receiving third mounting rod  114  and fourth mounting rod  120 . That is, as best seen in FIG. 8, third mounting rod  114  extends through apertures  112  of vehicle mounting bracket  108  and the aperture formed at the end of elongated main member  122  to define a third vertically oriented pivot axis E. Similarly, fourth mounting rod  120  extends through apertures  118  of door mounting bracket  116  and the aperture formed at the other end of elongated main member  122  to define a fourth vertically oriented pivot axis F. As can be seen in FIG. 8, third pivot axis E is generally parallel to and offset from fourth pivot axis F. 
     Still referring to FIGS. 7 and 8, rear hinge unit  26  further includes a pneumatic actuator assembly  124  generally disposed within rear door  24 . Pneumatic actuator assembly  124  is similarly configured as pneumatic actuator assembly  54 . 
     Referring particularly to FIG. 8, power-actuating device  30  of rear door system  14  includes an electric motor  126 , a drive cable  128 , a sector gear  130 , a drive linkage  132 , a bell crank  134 , and a driven linkage  136 . Electric motor  126 , drive cable  128 , sector gear  130 , drive linkage  132 , and driven linkage  136  are similar to electric motor  74 , drive cable  76 , sector gear  78 , drive linkage  80 , and driven linkage  84 . That is, drive linkage  132  is pivotally coupled to sector gear  130  at pivot  158 . 
     As best seen in FIG. 8, bell crank  134  is pivotally mounted to vehicle  10  at pivot  142 . Bell crank  134  is further pivotally coupled to drive linkage  132  at pivot  138  and pivotally coupled to driven linkage  136  at pivot  140 . Unlike bell crank  58 , which pivots about central pivot  68  to produce an output that is in the opposite direction as the input, pivot  142  is positioned at an end of bell crank  134 . Therefore, bell crank  134  produces an output that is in the same direction as the input; however, the output has a higher magnitude due to the amplifying effect of bell crank  134 . Unlike front door system  12  and as best seen in FIG. 8, driven linkage  136  is pivotally coupled to door mounting bracket  116  at tab  144 . Moreover, unlike front door system  12 , bell crank  134  further includes a protrusion  146 . Upon rotation of bell crank  134  about pivot  142 , driven linkage  136  drives door mounting bracket  116  and, thus, rear door  24 . However, after a predetermined amount of rotation, protrusion  146  of bell crank  134  contacts elongated main member  122 , thereby applying a driving force thereto. This contact between protrusion  146  of bell crank  134  and elongated main member  122  provides additional mechanical advantage to open rear door  24 . The operation of the remaining components is generally the same as those described with respect to front door system  12 . 
     Referring now to FIGS. 9-11, locking device  20  is shown having a bayonet  148  releasably disposed within a receiver  150 . That is, front door  16  and rear door  24  each include a bayonet  148  mounted to a lower edge thereof via threaded fasteners, welding, etc. Each bayonet  148  includes a locking extension  152  which extends generally parallel to a longitudinal or fore-and-aft plane of each door  16 ,  24 . Receiver  150  includes a pair of receiving channels  154  similarly extending generally parallel to a longitudinal axis of vehicle  10 . Engagement between locking extension  152  of bayonet  148  and receiver  150  is achieved by a sliding motion in a direction generally parallel to the plane of the door. It should be noted that although receiver  150  is shown as a single unit, receiver  150  might be separated to provide two set apart receiver channels. 
     The operation of front door system  12  and rear door system  14  will now be described in detail with reference to FIGS. 12-16. FIGS. 12-16 sequentially illustrate the simultaneous opening motion of front door  16  and rear door  24 . It should be appreciated, however, that front door  16  or rear door  24  may be opened or closed individually and are not required to be actuated in unison. However, in the interest of clarity of the disclosure, the opening motion of front door  16  and rear door  24  will be described together. It should also be noted that FIGS. 12-16 have portions of front hinge unit  18  and rear hinge unit  26  removed for additional clarity. 
     As best seen in FIG. 12, front door  16  and rear door  24  are shown in a fully closed and locked position. Upon actuation of front motor  74 , front drive linkage  80  is driven as described above. Front motor  74  is energized by controller  106  such as an occupant operated electric door switch or a remote controller (a.k.a. a keyfob). Referring to FIGS. 5 and 13, as drive linkage  80  is driven outwardly against tab  98  of U-shaped main member  46 , U-shaped main member  46  begins to rotate outwardly about axis A. This rotating motion of front door  16  about axis A causes an edge  156  of front door  16 , adjacent front hinge unit  18 , to first extend outward or “kick out.” During this time, locking extension  152  of bayonet  148 , which is mounted on the opposing edge of front door  16 , remains within receiving channel  154  of receiver  150 . This causes front door  16  to be generally angled inward from edge  156  to locking device  20 . 
     Referring to FIG. 13, upon continued actuation of front motor  74 , U-shaped main member  48  continues to rotate about pivot axis A. Simultaneously, front pneumatic actuator  56  begins to extend in the direction of arrow C due to the related motion of U-shaped main member  48  about pivot axis A. The extension of pneumatic actuator  56  against bell crank  58  causes bell crank  58  to pivot about central pivot  68 , thereby pulling interconnecting linkage  60  in the direction of arrow D. The result of this motion is that front door  16  is drawn toward U-shaped main member  48  about pivot axis B. As best seen in FIGS. 13 and 14, as U-shaped main member  48  rotates about pivot axis A, front door  16  also rotates about pivot axis B, thereby sliding locking extension  152  generally parallel to plane of front door  16 . Upon continued rotation about pivot axis A and pivot axis B, simultaneously, locking extension  152  is slid out of engagement with receiving channel  154 , thereby unlocking locking device  20 . Pneumatic actuator  56  will continue to draw or pull front door  16  toward U-shaped main member  48  until a physical stop (not shown) is reached, which prevents further relative motion therebetween. It should be noted, however, that until this physical stop is reached, an edge of locking extension  152  will generally remain in contact with vehicle  10  (see FIG.  14 ). 
     It is important to note that this initial “kick out” motion of edge  156  prior to rotation of front door  16  is advantageous in many respects. For example, this first “kick out” and rotation of the door provides much improved clearance between the door and the vehicle body panels. As noted in the background section, prior art methods are notorious for interference between the leading edge of the door and the body side panels. Thus, in convention methods, body side moldings were cut out or otherwise deformed to prevent such interference. Moreover, the gap spacing between the door and the body panel in conventional applications was larger to account for this potential for interference. In the present invention, this “kick out” motion overcomes these disadvantages in that the potential for interference is minimized and thus body side molding and gap spacing are improved. Moreover, this “kick out” motion occurs automatically in response to actuators  54 ,  124 , and, thus, facilitate the automatic locking extension  152  is slid out of engagement with receiving channel  154 . It should be understood that this sliding out motion, which is at least in part attributed to the “kick out” motion, enables a simple, yet strong locking mechanism to be used. This locking mechanism of the present invention does not require the typical locking mechanism, which includes various complicated latches, cables, and other components. features of the present invention. Still further, as a result of the “kick out” motion, 
     Referring to FIGS. 15 and 16, front door  16  is shown in an intermediate opened position and a fully opened position, respectively. As seen in FIG. 15, still further actuation of front motor  74  continues to rotate U-shaped main member  46  about axis A, while no relative motion is experienced about axis B between front door  16  and U-shaped main member  46 . Front door  16  will continue to rotate about axis A until front door is in a fully opened position (FIG.  16 ). To close front door  16 , an opposite drive motion occurs wherein front door  16  rotates about axis A until locking extension  152  contacts vehicle  10  and begins to slid within receiving channel  154 . This sliding motion is accompanied by the closing force overcoming the biasing force of pneumatic actuator  56  to cause pneumatic actuator  56  to compress. 
     Generally, the above described steps of opening and closing front door  16  apply to the opening and closing of rear door  24 . However, driven linkage  136  (FIG. 8) is coupled directly to door mounting bracket  116 , rather than to the main member (i.e. U-shaped main member or elongated main member). Therefore, the opening forces produced by rear motor  126  are applied directly to rear door  24  through door mounting bracket  116 . This arrangement provides the additional mechanical advantage necessary to actuate the front-access rear door  24 . However, it should also be noted that after a predetermined amount of rotation, protrusion  146  of bell crank  134  contacts elongated main member  122  such that force is then applied directly to elongated main member  122  at the contact point. This again allows improved mechanical advantages necessary to actuate the front-access rear door  24 . 
     During manual opening of front door  16  or rear door  24 , it is preferable to bypass sector gears  78  and  146 , respectively, upon detection of a user actuating the door handle. This would enable the pneumatic actuators (i.e.  56 ) to “pop” or “kick” the edge of the door outward, thereby unlocking the door from the respective locking device and enabling the user to manually open or close the door. More particularly, when sector gears  78  and  146  are bypassed, upper plate member  86  is free to rotate independently from lower plate member  88 . As one will recall, when upper plate member  86  is interlocked with lower plate member  88 , sector gear  78  overcomes the biasing force of actuator  54 . When upper plate  86  is unlatched from lower plate member  88 , the biasing force of actuator  54  is free to act upon front door  16 . The force exerted, as described above, will act in the direction of arrow D (FIG.  5 ), thereby drawing front door  16  toward hinge unit  18  about axis B. This motion acts to “kick” edge  156  outward and unlock locking device  20 , thereby enabling manual articulation of front door  16 . 
     As been seen in FIGS. 3 and 16, the vehicle door system of the present invention provides an enlarged opening for ingress and egress from the vehicle relative to conventional arrangements. By way of a non-limiting example, the vehicle door system of the present invention enables the front door and rear door to each be opened at least 70° and, more preferably, to open approximately 90°. However, it should also be understood that the front door and rear door may be opened approximately 180° should it be desired to “fold” the doors generally adjacent the forward and rearward body panels. According to an alternative embodiment of the present invention, if the vehicle door system is used as a rear door(s) on a van, the door(s) could open more than 180° (e.g. 270°) to again fold generally adjacent the side body panels of the van. Therefore, the doors would be rotated out of the way to permit an unobstructed walking path around the vehicle. Particularly in FIG. 3, one can appreciate that the ease of use and aesthetic benefits of such enlarged openings of the present invention, which could not be attained using conventional single pivot hinge mechanisms, are afforded by the present invention. This is especially desirable for elderly, handicapped, or larger occupants. Moreover, one can appreciate the aesthetic benefits to having a single, continuous opening allowing access to the cabin of the vehicle. 
     While the preferred embodiment has been disclosed herein, it should appreciated that other variations may be employed within scope of the present invention. For example, the electric motors and driving links can be placed inside the doors. Furthermore, cables or gears may be substituted for several of the disclosed linkages. Hydraulic actuation can also be employed, although with some assembly and modularity disadvantages. The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.