Derrick

Claim 1

A PORTABLE COLLAPSIBLE TYPE DERRICK COMPRISING A BASE MOUNTED ON A SUPPORT FOR ROTARY MOVEMENT IN A GENERALLY HORIZONTAL PLANE, MEANS FOR ROTATING SAID BASE, A BOOM PIVOTALLY MOUNTED AT ONE END ON SAID BASE FOR SWINGING MOVEMENT IN A GENERALLY VERTICAL PLANE FROM A FORWARD STORAGE POSITION TO REARWARD LOAD SUPPORTING POSITION, SAID BOOM COMPRISING AN INNER SECTION AND AN OUTER EXTENDIBLE SECTION ADAPTED FOR LENGTHWISE TELESCOPING RELATION WITH SAID INNER SECTION FOR VARYING THE EFFECTIVE LENGTH OF SAID BOOM, MEANS INCLUDING A RECIPROCAL MOTOR UNIT FOR TELESCOPING SAID OUTER BOOM SECTION WITH RESPECT TO SAID INNER BOOM SECTION, AND MEANS FOR MOVING SAID BOOM FROM SAID STORAGE POSITION TO LOAD SUPPORTING POSITION AND VICE-VERSA, SAID LAST MENTIONED MEANS COMPRISING POWERED RECIPROCAL MEANS PIVOTALLY CONNECTED AT ONE END THEREOF TO THE BOOM OUTWARDLY THEREALONG FROM THE PIVOTAL CONNECTION OF SAID BOOM TO SAID BASE, SAID POWERED RECIPROCAL MEANS BEING DISPOSED ABOVE SAID BOOM IN SAID STORAGE POSITION THEREOF, LINK MEANS PIVOTALLY CONNECTED TO SAID BASE DOWNWARDLY FROM THE PIVOTAL CONNECTION OF SAID BOOM TO SAID BASE, SAID LINK MEANS BEING DISPOSED GENERALLY REARWARDLY OF SAID PIVOTAL CONNECTION OF SAID BOOM TO SAID BASE AND BEING ADAPTED FOR PIVOTAL MOVEMENT IN A GENERALLY VERTICAL PLANE AND WITH RESPECT TO SAID BASE, THE OTHER END OF SAID RECIPROCAL MEANS BEING PIVOTALLY CONNECTED TO SAID LINK MEANS OUTWARDLY THEREALONG FROM THE PIVOTAL CONNECTION OF SAID LINK MEANS TO SAID BASE, AND SECOND LINK MEANS EXTENDING BETWEEN SAID FIRST LINK MEANS AND SAID BOOM AND BEING PIVOTALLY CONNECTED THERETO, THE PIVOTAL CONNECTION OF SAID SECOND LINK MEANS TO SAID BOOM BEING DISPOSED ABOVE A HORIZONTAL PLANE PASSING THROUGH THE PIVOTAL CONNECTION OF SAID SECOND LINK MEANS TO SAID FIRST LINK MEANS THROUGHOUT THE RANGE OF PIVOTAL MOVEMENT OF SAID BOOM, SAID SECOND LINK MEANS OPERATING TO PIVOT SAID FIRST LINK MEANS REARWARDLY AWAY FROM THE PIVOTAL CONNECTION OF THE SAID BOOM TO SAID BASE UPON ACTUATION OF SAID POWERED RECIPROCAL MEANS TO MOVE SAID BOOM FROM STORAGE POSITION TO LOAD SUPPORTING POSITION, TO THEREBY PIVOT SAID RECIPROCAL MEANS OUTWARDLY FROM SAID BOOM ABOUT ITS PIVOTAL CONNECTION TO SAID BOOM AND AWAY FROM THE PIVOTAL CONNECTION OF SAID BOOM TO SAID BASE.