Gangway having position locking assembly
A gangway comprising a fixed platform. A support structure is connected to the fixed platform in a manner that allows the support structure to rotate with respect to the fixed platform. A releasable position locking assembly that inhibits rotation of the support structure in a raising direction is also provided. The releasable locking assembly includes a closed-loop fluid arrangement.
1. A gangway comprising:
a support structure having a proximal end and a distal end, the proximal end of the support structure being pivotally connected to a platform;
a cage assembly pivotally connected to the distal end of the support structure; and
a releasable position locking assembly that inhibits rotation of said support structure in a raising direction, said releasable locking assembly including a closed-loop fluid arrangement having a cylinder in which a piston reciprocates and fluid handling components that selectively allow flow of fluid to a first side of said piston for raising of said support structure when the releasable position locking assembly is unlocked.
2. The gangway of claim 1 , wherein said cylinder and said fluid handling components are integrated into a cylinder unit connected between said support structure and a fixed attachment structure.
3. The gangway of claim 1 , wherein said fluid handling components include a check valve through which fluid transfers from the first side of said piston to a second side of said piston.
4. The gangway of claim 1 , wherein said fluid handling components include an unlock valve that when opened allows flow of fluid to said first side of said piston.
5. The gangway of claim 4 , wherein said unlock valve comprises a manual pull valve.
6. The gangway of claim 4 , wherein said fluid handling components further comprise a relief valve configured to allow transfer of fluid from a second side of said piston back to the first side of said piston when a predetermined threshold pressure is encountered.
7. The gangway of claim 1 , wherein said fluid handling components comprise an accumulator for receiving excess fluid due to volume occupied by a piston rod of the piston.
8. The gangway of claim 7 , wherein said accumulator comprises a free piston movable against a spring.
9. The gangway of claim 8 , wherein said free piston carries a stop feature to limit its axial movement against said spring.