| 摘要 |
A method of folding a mast or derrick and a folding mast apparatus having a back face and a pair of opposed sides with each of the opposed sides having a front leg and a back leg. The apparatus includes at least one spreader beam assembly extending across the back face and connecting the back legs of the pair of opposed sides. At least one pair of telescoping braces extends between the at least one spreader beam assembly and the back legs. A pair of mast folding cylinders, each of the cylinders extending between one back leg and the back face, moves the pair of opposed sides between an open, use position and a closed, transportation position. |
