the first connector element 82 is forced to move along its own longitudinal axis relative to the force distribution plate 91 this in turn moves the keeper bar means 84 also relative to the force distribution plate 91 accordingly rotation of the second connector element 80 relative to the first connector element 82 causes linear movement of connector element 82 as well as keeper bar means 84 towards the force distribution plate 91 as best shown in fig7 the length of the keeper bar means 84 is greater than the width of the entrance means 43 to each of the slots 40 also the keeper bar means is arranged substantially transverse to the longitudinal axis of the slot 40 and to the length of the entrance means 43 based on the above a clamping action takes place about the lips 45 by the keeper bar means 84 on the interior of the slot 40 and by the force distribution plate 91 on the exterior of the slot 40 this securely mounts the entire clamp assembly in the desired position along the length of any of the given slots in which it is mounted this also serves to maintain the support arm 71 in an outwardly extending relation to the exposed surface 90 of the force distribution plate 91 this in turn allows shelving to be placed on the upper portion 71 of support arm 70 or various items to be hung in depending fashion from the various hooks or support elements 76 with reference to fig6 this embodiment of.