Image Number 6 for United States Patent #4337596.
An actuating mechanism for sliding doors provided on the passenger side of conventional panel-type trucks, commonly called vans, is intended to be either installed in the vehicle at the time of its original manufacture, or installed at any later time, without substantial modification of the vehicle. A winch assembly (44) including two separate winding drums (74, 86) on a common shaft (87) and driven by the shaft through springs (162, 174) and a positive driver (170), is mounted over the rear wheel well of such a vehicle. A guide assembly (50) including a pulley (54) and a pivoting guide member (62) is installed in an aperture cut in the door frame. A single pulley (56) is installed at the lower rear corner of the door opening, and a guide tube (58) is installed in the door. A flexible cable (52) is connected to an arm added to the latch operating mechanism, and extends through the guide tube (58), around the pulley (56), through the guiding assembly (50) to the winch assembly (44), for opening the door. A second cable (60) is attached to the rear edge of the door, passed around the pivoting guide (62) of the guide assembly, and fastened to the winch assembly (44) for closing the door. As the door closes, the pivoting guide (62) guides the flexible cable (60) to a position perpendicular to the rear edge of the door to pull the rear edge of the door into latched position. A switch (55) operated by the pivoting guide (62) connects an additional winding on an electric motor (138) to provide a high force for latching the door, allowing low force to be used for sliding the door to reduce the chance of personal injuries while closing the door.