mount 61 on latch retractor bar 36 and at a lower end thereof to a spring mount 63 on latch bar retractor retainer 37 in the illustrated embodiment retractor bar return spring 62 is an elongated coiled extension spring as shown in fig5 retractor bar lift handle 64 includes a hand grip 66 formed to include a finger receiver 68 and a pivot support arm 70 cantilevered to hand grip 66 and mounted at a free end thereof to a pivot pin 72 coupled to tube 29 of frame 25 hand grip 66 is thus supported for pivotable movement about a pivot axis established by pivot pin 72 between a lowered position shown for example in fig1 3 5 7 and 8 and a raised position shown for example in fig9 hand grip 66 is pivotably coupled to an upper end of latch retractor bar 36 at pivot mount 74 as shown for example in fig5 and 7 9 in the lowered position of hand grip 66 latch bar retractor 36 remains in its lowered position movement of hand grip 66 to its raised position as shown in fig9 lifts latch retractor bar 36 upwardly in guide channel 38 provided in latch base 30 to move simultaneously both spring biased upper and lower latches 24 26 laterally to withdraw plunger posts 28 from post receivers 124 126 formed in latch receiver frame 18 in the embodiment illustrated in fig4 a first handle.