Device for locking together stacked objects

A device for locking together two stacked objects, the lower object having a plate at its upper end and the upper object having a plate at its lower end, the two plates being in superposed relation when the objects are stacked and each plate having a non-circular opening identical to and in registry with the opening in the other plate, the locking device comprising:

• (a) a housing, the top wall of the housing being the plate of the lower object, the housing having a support surface within it and two side walls, each side wall having a front edge and one of the front edges having two pockets,
• (b) a bolt within the housing movable vertically and rotatably with respect to the housing, the bolt having a head piece shaped to pass through the plate openings when the bolt is in a first angular orientation but not when the bolt is in a second angular orientation,
• (c) a structural unit coaxial with the bolt and movable vertically with the bolt, the structural unit being rotatable with respect to the bolt and to the housing and having a supporting shoulder which does not engage the support surface of the housing when the structural unit is in a first angular orientation but does engage the support surface when the structural unit is in a second angular orientation,
• (d) two levers for simultaneously moving the bolt and structural unit vertically between extreme upper and lower positions, movement of the bolt and structural unit upwardly while they are in their first angular orientations passing the bolt head piece through the opening in the plate of the lower object and elevating the supporting shoulder above the housing support surface, one of said levers being arranged to rotate the structural unit to its second angular orientation so that the supporting shoulder engages the housing support surface to maintain the structural unit and bolt in their raised positions, and the other of said levers being arranged to rotate the bolt to its second angular orientation, after an upper object is stacked on the lower object with the bolt head piece passing the opening in the plate of the upper object, so as to lock the two objects together, and
• (e) the two levers extending out of the housing between the side walls thereof during vertical movement of the bolt and structural unit, both levers being located with each of the two pockets in the housing when the bolt and structural unit are in each of their two extreme positions, respectively, and also in their second angular orientations.