| 20080250727 | Raising and Lowering of Columns - An arrangement for the raising and lowering of a mast, which includes an upper mast portion and base, which upper mast portion is rotatable about a horizontal pivot axis, located in the base of the mast is described. The arrangement includes (i) docking device for restraining the upper mast portion against rotation; (ii) attachment device for attaching a drive device for driving the docking device between a first engaged configuration wherein the upper mast portion is restrained against rotation and a second disengaged configuration wherein the upper mast portion is free to rotate and (iii) locking device selectable via an intermediate unlocked configuration between a first locked configuration wherein the docking device is engaged and a second unlocked configuration wherein the docking device is disengaged and is characterized in that the locking means is controllable remotely to allow automatic operation of the raising and lowering sequence. | 10-16-2008 |
