Patent ID: 8469653

Claim:
A method for engaging a cell from a vertical portal, employing a carriage having a cell carrier and having a portal engagement device having limited vertical movement with respect to said cell carrier, said portal engagement device configured to engage said vertical portal; comprising the steps of: A. when said portal engagement device is engaged with said vertical portal and receiving said vertically driven cell from said vertical portal, guiding a spring loaded cam follower hook of said cell sideways from a rest position as said cell is driven vertically from said vertical portal to said portal engagement device; B. allowing centering movement of said spring loaded cam follower hook back towards and short of said rest position; and C. engaging said cam follower hook against downward movement, said cam follower hook thereby supporting said cell with respect to said cell carrier, and thereby engaging said cell, and retaining said cell against downward vertical movement with respect to said cell carrier, such that further downward vertical drive of said vertically driven cell from said portal engagement device instead moves said portal engagement device upward to disengage said portal engagement device from said vertical portal.