Single boom derrick units

Claim 1

A SINGLE BOOM DERRICK UNIT FOR MOBILE PLATFORMS AND THE LIKE, SAID DERRICK UNIT COMPRISING SUPPORT MEANS, A MAST ASSEMBLY ROTATABLY MOUNTED ON SAID SUPPORT MEANS, A BOOM OPERATIVELY MOUNTED ON SAID MAST ASSEMBLY AND BEING ADAPTED TO SWING THROUGH AN ARC IN A VERTICAL PLANE WITH RESPECT TO SAID MAST ASSEMBLY, SAID BOOM HAVING A FIRST SECTION PIVOTALLY CONNECTED AT A FIRST PIVOT POINT TO THE MAST ASSEMBLY AND A SECOND SECTION WHICH IS PIVOTALLY CONNECTED TO THE FIRST SECTION AT A SECOND PIVOT POINT, SAID FIRST PIVOT POINT AND SECOND PIVOT POINT LYING WITHIN THE SAME HORIZONTAL PLANE WHEN SAID FIRST SECTION IS EXTENDED IN A HORIZONTAL POSITION, SAID FIRST SECTION BEING PROVIDED WITH AN OFFSET PORTION THAT PROJECTS OUTWARDLY AND DOWNWARDLY FROM THE SECOND PIVOT POINT WHEN SAID FIRST AND SECOND PIVOT POINTS LIE IN A SUBSTANTIALLY HORIZONTAL PLANE, SAID OFFSET PORTION HAVING A THIRD PIVOT POINT THAT LIES DOWNWARDLY AND OUTWARDLY FROM THE SECOND PIVOT POINT WHEN SAID FIRST AND SECOND PIVOT POINTS LIE IN A SUBSTANTIALLY HORIZONTAL PLANE, FIRST HYDRAULIC RAM MEANS CONNECTED TO THE MAST ASSEMBLY AND TO THE THIRD PIVOT POINT FOR SWINGING SAID FIRST SECTION WITH RESPECT TO SAID MAST ASSEMBLY, SECOND HYDRAULIC RAM MEANS CONNECTED TO THE THIRD PIVOT POINT AND THE SECOND SECTION FOR SWINGING IT WITH RESPECT TO THE FIRST SECTION, AND HYDRAULIC MOTOR MEANS MOUNTED WITHIN AND BEING OPERATIVELY CONNECTED TO SAID MAST ASSEMBLY FOR ROTATING SAID MAST ASSEMBLY WITH RESPECT TO SAID SUPPORT MEANS.