numeral 78 included in the slider assembly 78 there is a pair of generally parallel axial members 80 and 82 on each of these axial members there are respectively mounting brackets 84 and 86 for mounting the fifth wheel which is shown in fig2 in phantom lines at numeral 87 the mounting brackets 84 and 86 may preferably be welded directly to the parallel axial members 80 and 82 respectively the slider assembly 78 has medial transverse members 88 and 90 on transverse member 88 there is mounted lateral arm 92 which has distal fingers as at finger 94 in opposed relation to lateral arm 92 there is a lateral arm 96 having distal fingers as at finger 98 restraining lateral arms 92 and 96 respectively there are springs 100 and 102 motion of these lateral arms is controlled in part by guide features as at features 104 106 108 110 and 112 there is also a pivot plate 113 and a mounting bar 114 and lateral arm 92 is pivotally mounted on this pivot plate at pivot point 116 while lateral arm 96 is mounted at pivot point 118 on the pivot plate 113 there is also a forward pivot point 120 at which it is connected to a spring biased piston and cylinder combination 122 this piston and cylinder combination 122 is connected at its opposed end to member 80 of the slider assembly through member 125 fig3 preferably the piston and cylinder combination 122 is a pneumatic piston and cylinder combination this piston and cylinder combination 122 is spring.