Crane boom

Claim 1

A CRANE, COMPRISING A SUPPORT, A TURNABLE MOUNTED ON SAID SUPPORT FOR ROTATION ABOUT A GENERALLY VERTICAL AXIS, AN ELONGATED SHIPPER MOUNTED ON SAID TURNTABLE FOR ROTATION ABOUT A GENERALLY HORIZONTAL AXIS, HYDRAULIC MEANS INTERCONNECTING SAID SHIPPER AND TURNTABLE FOR SELECTIVELY POSITIONING AND SHIPPER AT VARIOUS ANGLES RELATIVE TO THE GROUND, A BOOM SLIDABLY MOUNTED IN SAID SHIPPER FOR SELECTIVE EXTENSION AND RETRACTION RELATIVE TO SAID SHIPPER, SAID BOOM BEING ADAPTED TO BE EXTENDED RELATIVE TO SAID SHIPPER AND HAVING AT THE OUTER END THEREOF A CROWN ASSEMBLY OPERABLY ASSOCIATED THEREWITH AND ADAPTED FOR SELECTIVE COMMON MOVEMENT WITH SAID BOOM, A HYDRAULIC CYLINDER AND PISTON ROD UNIT LOCATED COAXIALLY WITH AND INTERIORLY OF SAID BOOM WITH THE CYLINDER PORTION PIVOTALLY CONNECTED TO THE BASE OF SAID SHIPPER, MEANS CONNECTING THE PISTON ROD PORTION OF SAID UNIT TO SAID BOOM, SAID CONNECTING MEANS INCLUDING A PULLER TUBE MOUNTED COAXIALLY WITH AND INTERIORLY OF SAID BOOM WITH SAID UNIT BEING SUBSTANTIALLY RECEIVED WITHIN SAID PULLER ELEMENT, PIN MEANS COUPLING THE PISTON ROD PORTION OF SAID UNIT TO SAID PULLER ELEMENT ADJACENT THE OUTER END OF SAID PULLER ELEMENT, AND SEGMENTAL SHAFT MEANS PIVOTALLY CONNECTING SAID PULLER ELEMENT, SAID PULLER ELEMENT THE INNER END OF SAID PULLER ELEMENT, SAID PULLER ELEMENT BEING OF SMALLER DIAMETER THAN SAID BOOM SUFFICIENT TO DEFINED AN ANNULAR SPACED BETWEEN SAID PULLER ELEMENT AND SAID BOOM FOR TELESCOPICALLY RECEIVING A BOOM EXTENSION COAXIALLY WITH SAID BOOM.