Abstract:
A passenger van is equipped with a drive mechanism for power operation of a slideable side door. The drive mechanism has a flexible drive cable that travels in a closed loop that includes cable portions that travel through a center track in opposite directions. The center track supports and guides a roller assembly that is attached to the rear of the side door. The roller assembly carries a cinch mechanism that selectively connects the roller assembly to a portion of the cable that is traveling in one direction to open the sliding door and that selectively connects the roller assembly to a portion of the cable that is traveling in the opposite direction to close the sliding door. The cinch mechanism is normally disconnected from the cable so that the side door can be opened or closed manually very easily.

Description:
FIELD OF THE INVENTION 
     This invention relates to automotive vehicles having a slideable side door and more particularly to a drive mechanism for a power operated slideable side door. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 5,316,365 granted to Howard W. Kuhlman and Jeffrey K. Joyner May 31, 1994 discloses a passenger van that has a slidable side door. The door is supported on and slideable in three tracks. A module for power operation of the door is mounted inside the van adjacent to the center track that supports and guides the rear of the door. The module includes a front cable and a rear cable. The front cable is attached to a front cable drive pulley, then extends through a front cable roller guide assembly and is then attached to a roller assembly. The rear cable is attached to a rear cable drive pulley then extends through a rear cable roller guide assembly, and is then attached to the roller assembly. The front and rear cable drive pulleys are driven by a reversible electric motor that is driven in one direction to open the sliding door and in the opposite direction to close the sliding door. 
     U.S. Pat. No. 4,932,715 granted to Hans Kramer Jun. 12, 1990 discloses a passenger van that has a slidable side door that is opened and closed by a mechanism that includes a roller carriage in a track. The roller carriage and hence the side door is driven by an endless round cable that travels in a closed loop with a strand or portion of the cable being disposed in the track and attached to the roller carriage. The cable is driven by a driving roller which is turn is driven by an electric motor via an electromagnetic clutch. The electric motor is reversible so that the cable is driven in one direction to open the side door and in an opposite direction to close the side door. See also U.S. Pat. No. 5,168,666 granted to Soushichi Koura et al Dec. 8, 1992; and U.S. Pat. No. 6,081,088 granted to Hidenori Ishihara et al Jun. 27, 2000. 
     Copending Patent Application Ser. No. 09/867,863, filed May 30, 2001, discloses a drive mechanism for power operation of a slideable side door of an automotive vehicle that is characterized by a roller assembly that includes a clutch for clamping onto a flexible drive member that is driven in a loop by a reversible electric motor. To open the side door, the clutch is engaged and the flexible drive member is driven in the loop in one direction. To close the side door, the flexible drive member is driven in the opposite direction. See also copending Patent Application Ser. No. 09/978,908, filed Oct. 16, 2001. 
     SUMMARY OF THE INVENTION 
     This invention provides a drive mechanism for power operation of a slideable side door of an automotive vehicle, such as a passenger van. 
     In one aspect, the drive mechanism has a flexible drive member trained to travel in a loop so that an upper portion of the loop and a lower portion of the loop that travel in opposite directions are disposed in a track juxtaposed a roller assembly that is attached to the side door. A drive mechanism is operatively connected to the flexible drive member to drive the flexible drive member in the loop, and a cinch mechanism is mounted on the roller assembly for connecting the roller assembly to the flexible drive member selectively. The cinch mechanism has an upper clutch for engaging the upper portion of the flexible drive member to drive the side door in one direction, and a lower clutch for engaging the lower portion of the flexible drive member to drive the side door in an opposite direction. Thus the side door can be opened and closed without any need for a reversible electric motor to reverse the travel direction of the flexible drive member. 
     In another aspect, the drive mechanism has a flexible drive member that is a round cable of uniform diameter and a cinch mechanism for connecting the roller assembly to the round cable of uniform diameter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a passenger van equipped with a sliding side door of the invention; 
     FIG. 2 is a schematic perspective view of the drive mechanism for opening and closing the sliding side door shown in FIG. 1; 
     FIG. 3 is an enlarged perspective view of a hinge and roller assembly in the drive mechanism shown in FIG. 2; and 
     FIG. 4 is a section taken substantially along the line  4 — 4  of FIG. 3 looking in the direction of the arrows with the cincher disengaged. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIGS. 1 and 2, an automotive vehicle, such as a passenger van  10  has a hinged front door  12  on each side of the vehicle and at least one sliding side door  14  behind the front doors that may be power driven. Such vehicles are well known and need not be described in detail. See for instance the Kuhlman &#39;365 patent discussed above. 
     The power sliding door  14  is supported and guided by an upper track  16 , a center track  18 , and a lower track  20  as shown in FIG.  1 . An upper roller assembly  22  is attached to the upper forward corner of the power sliding door and runs in the upper track  16 . A lower roller assembly  24  is attached to the lower forward comer of the power sliding door and runs in the lower track  20 . A third roller assembly  26  is pivotally attached to the rear portion of the power sliding door  14  between the upper and lower portions of the power sliding door. 
     Referring now to FIGS. 2 and 3, roller assembly  26  has a carriage  28 . A support roller  30  pivotally attached to carriage  28  for rotation about a generally horizontal axis, supports the rear portion of door  14  and runs in the center track  18 . Two guide rollers  32  and  34  are pivotally attached to carriage  28  for rotation about generally vertical axes and run in an upper channel portion  36  of the center track  18 . A vertical hinge pin  38  passes through a pair of hinge apertures in carriage  28  and through hinge apertures in a bracket  29  attached to the rear edge of the power sliding door  14  to connect carriage  28  to power sliding door  14 . 
     The power sliding door  14  moves horizontally inward toward the center of the van  10  for latching and sealing. Latches  42  and  44  are provided at the front and rear of the power sliding door  14  which moves horizontally inward to compress resilient seals and to latch. Inward horizontal movement of the sliding door  14  is obtained by curving the forward ends of the upper, center and lower tracks  16 ,  18  and  20  inwardly toward the center of van  10 . When the hinge and roller assembly  26  passes around the curved forward end  45  of center track  18 , the hinge and roller assembly  26  pivots inwardly and moves the rear portion of side door  14  horizontally inward toward the side of van  10 . 
     The drive mechanism  50  for opening and closing the side door  14  comprises the roller assembly  26  and further includes a flexible drive member  52  that travels in a closed loop with upper and lower portions  56 ,  58  of the loop disposed in track  18  along the entire length of the track as best shown in FIG.  2 . The portions of the loop disposed in track  18  travel in close proximity to the roller assembly  26 . Flexible drive member  52  is preferably an endless round cable  54  that has a smooth outer surface. 
     A front pulley  60  engages the flexible drive member  52  at a front end of track  18  and a rear cable guide  62  engages the flexible drive member  52  at a rear end of the track  18 . Cable guide  62  may be stationary as shown or may be a rotatable pulley (not shown). Upper and lower portions  56 ,  58  of the loop that are disposed inside track  18  run in opposite directions as indicated by the arrows in FIG.  2 . 
     A drive assembly  66  is attached to van  10  in any suitable manner. Drive assembly  66  comprises an electric motor  68  that drives an optional electromagnetic clutch such as clutch  70 . Clutch  70  in turn drives front pulley  60  via a gear reduction unit  71 . Front drive pulley  60  is configured to drive cable  54  in a loop as best shown in FIG.  2 . 
     The roller assembly  26  includes a cinch mechanism  72  for clamping hinge and roller assembly  26  to either the upper portion  56  of flexible drive member  52  to drive the roller assembly  26  in one direction or to the lower portion  58  to drive the roller assembly  26  in the opposite direction as shown by the arrows in FIG.  2 . 
     Cinch mechanism  72  comprises a drive drum  74  for operating upper and lower clutches  76  and  78  that comprise upper and lower lariats  80  and  82  and upper and lower stops  84  and  86 , respectively. Upper lariat  80  has a noose  88  at one end that encircles the upper portion  56  of flexible drive member  52  and that is located adjacent upper stop  84  which may conveniently be formed as a bent tab of carriage  28 . The opposite end of lariat  80  is attached to drive drum  74 . Lower lariat  82  has a noose  90  at one end that encircles the lower portion  58  of flexible drive member  52  and that is located adjacent lower stop  86  which also may conveniently formed as a bent tab of carriage  28 . The opposite end of lariat  82  is also attached to drive drum  74 . The opposite ends of lariats  80  and  82  are attached to drive drum  74  at spaced locations so that upper lariat  80  is wound on drum  74  while lower lariat  82  is payed off drum  74  when drive drum  74  is displaced or indexed angularly in one direction. When upper lariat  80  is wound on drum  74 , upper portion  56  of flexible drive member  52  is pulled against upper stop  84  and upper noose  88  tightens around and grips the upper portion  56  of flexible drive member  52 . The lower noose  90  is simultaneously further loosened on the lower portion  58  of the flexible drive member  52  as lower lariat  82  is payed off drum  74 . The opposite happens when drive drum  74  is indexed in the opposite direction, that is, upper lariat  80  is payed off drum  74  and noose  88  is loosened while lower lariat  82  is wound on drum  74  and noose  90  is tightened gripping the lower portion  58  of the flexible drive member  52 . 
     The angularly indexable drive drum  74  has open, neutral and close positions illustrated schematically as O, N and C in FIG.  4 . Flexible drive member  52  slides through lariats  80  and  82  when drive drum  74  is in the neutral position so that the side door  14  can be opened or closed manually without any resistance from cinch mechanism  72 . To open the side door  14 , motor  68  and the optional electromagnetic clutch  70  if one is used are energized and drive drum  74  is indexed (clockwise as shown in FIG. 4) to the open position through suitable controls which are not shown but well within the skill of a person of ordinary skill in the art. The energization of motor  68  and electromagnetic clutch  70  and the indexing of drive drum  74  can occur in any order but the energization preferably occur simultaneously. In any event, the energization causes flexible drive member  52  to travel in a loop in the clockwise direction as viewed and as shown by the arrows in FIG. 2 while indexing drum  74  to the open position causes upper clutch  76  to engage the upper portion  56  of flexible drive member  52  and move the side door  14  from the closed position to the open position, that is, to the right as shown in FIG.  2 . As upper noose  88  of upper clutch  76  tightens around the upper portion  56  of flexible drive member  52  to engage the upper clutch  76 , the lower noose  90  of lower clutch  80  is simultaneously further loosened from its slipping neutral condition removing any possibility of the lower clutch  80  interfering with the side door  14  traveling to the open position. 
     To close the side door  14 , motor  68  and the optional electromagnetic clutch  70  are energized and drive drum  74  is indexed to the close position. Energization of motor  68  and electromagnetic clutch  70  still causes flexible drive member  52  to travel in a loop in the clockwise direction as viewed FIG.  2 . However, indexing drive drum  74  to the close position causes lower clutch  78  to engage the lower portion  58  of flexible drive member  52  and move the side door  14  from the open position to the closed position, that is to the left as shown in FIG.  2 . As lower noose  90  of lower clutch  78  tightens around the lower portion  58  of flexible drive member  52  to engage the lower clutch  78 , the upper noose  88  of upper clutch  76  is simultaneously further loosened from its slipping neutral condition removing any possibility of the upper clutch  76  interfering with the side door traveling to the closed position. Thus drive mechanism  50  opens and closes side door  14  without any need for reversing the travel of the flexible drive member  52  or the rotation of the electric motor  68 . Hence a reversible electric motor is not necessary. It should also be noted that the flexible drive member  52  can take the economical form of a round cable  54  of uniform diameter. 
     While a specific embodiment has been illustrated, other embodiments are possible. For instance, the electromagnetic clutch  70  can be eliminated for economy. Moreover, while the preferred embodiment is illustrated with a drive pulley  60  and only one cable guide  60  for driving and guiding the flexible drive member  52  additional guides, both stationary and rotary can be used to establish the travel loop for the flexible drive member  52 . Furthermore, the parts of the drive mechanism can be rearranged so that the sprocket  60 , motor  68  and electromagnetic clutch  70  are at a rear end of track  18 . In other words, while a preferred embodiment of the invention has been shown and described, other embodiments will now become apparent to those skilled in the art. Accordingly, the invention is not to be limited to that which is shown and described but by the following claims.