of crank arm 69a is connected to rod 68 and the other end is connected to the end of link 24 in locking unlocking mechanism 70 when in the lock condition as shown in fig1 even if opening linkage cable 23 is pulled locking unlocking pin 79 only moves along locking groove 72d of unlocking lever 72 and does not have any other motion it swings wide and therefore motion is not transmitted to door lock 60 therefore the door cannot be unlocked and thus sliding door 20 cannot be opened even if any one of the cables were pulled by some object from the outside sliding door 20 still cannot be opened either one of locking unlocking knob 74 actuator 75 and key cylinder 76 by way of either one of knob rod 74a auto rod 75a and key rod 76a cause locking unlocking lever 71 to rotate in a clockwise direction as shown in fig1 when the lever is rotated into the unlock position locking unlocking pin 79 is pushed along unlocking guide groove 71c and moves inside of unlocking groove 72e of unlocking lever 72 and consequently locking unlocking mechanism 70 is unlocked in the unlock position when opening linkage cable 23 pulls first edge 72b of locking unlocking lever 72 locking unlocking pin 79 moves along unlocking groove 72e to pull link 24 when this happens crank arm 69a of bell crank 69 is rotated and rod 68.