Self-leveling cargo container spreader

Claim 1

A SPREADER FOR LIFTING CARGO CONTAINERS COMPRISING: (A) A FRAME DISPOSED, DURING OPERATION, PRIMARILY IN A HORIZONTAL PLANE AND HAVING A PLURALITY OF HORIZONTALLY SPACED MEANS FOR CONNECTING IT IN SUBSTANTIALLY FIXED RELATION TO THE TOP PORTION OF A CARGO CONTAINER; (B) A PLURALITY OF GIDES MOUNTED IN SAID FRAME DISPOSED ON OPPOSITE SIDES OF, SAND IN SPACED TRANSVERSE WITH, A VERTICAL PLANE EXTENDING IN CENTRAL TRANSVERSE RELATION WITH THE FRAME; (C) A LIFTING SHACKLE NORMALLY SUSPENDED OVER THE FRAME; (D) FLEXIBLE, SUBSTANTIALLY NON-ELASTIC TENSION MEANS SECURED TO THE SHACKLE AND EXTENDING THEREFROM AROUND EACH OF SAID GUIDES TOWARD SAID VERTICAL PLANE; (E) LEVEL-ADJUSTING MEANS FOR THE FRAME CARRIED THEREBY AND CONNECTED WITH THE TENSION MEANS, SAID ADJUSTING MEANS BEING MOVABLE TO PULL A PORTION OF SAID TENSION MEANS OVER RESPECTIVE GUIDES AT ONE SIDE OF SAID PLANE TOWARD THE PLANE AND TO DISCHARGE OTHER OF SAID TENSION MEANS AWAY FROM SAID PLANE OVER RESPECTIVE GUIDES AT THE OTHER SIDE OF SAID PLANE; AND (F) SAID TENSION MEANS BEING OF AN ARRANGEMENT AND OF SUFFICIENT LENGTH TO DISPOSE SAID SHACKLE DURING OPERATION IN CENTRAL AND UPWARDLY SPACED RELATION WITH THE FRAME WHEN SAID LEVEL ADJUSTING MEANS IS IN AN INTERMEDIATE CONDITION OF ADJUSTMENT.