84 to slide rail 85 coil spring 87 biases the handle 83 in the position shown into the position shown in fig8 spring 87 acts in the same manner as spring 67 of fig6 with respect to the movement and retraction of handle 83 relative to slide rail 85 fig9 shows a side guide 91 having a handle 93 that is connected to slide rail 95 via a four bar linkage system 97 only two shown u2014 other side has two bars while the links 97 pivot about their connections on the slide rail 95 the handle 93 moves up and toward the mailpiecess when force f is applied the handle 93 during its movement always maintains its planar surface 98 in a parallel orientation relative to slide rail 95 the handle 93 moves until its back end 94 contacts the rear end 96 of slide rail 95 at which point the slide rail 95 and handle 93 move together toward the mailpieces spring 99 returns the handle 93 to the position of fig9 upon removal of force f fig1 shows yet another side guide 101 having a handle 103 and a rack and pinion system including rack components 107 109 and pinions 110 connected via a shaft 111 the upper rack portions 107 are attached to the handle 103 and the lower rack.