The subject of the invention is the method and device for locking rope winch.
This invention may, in particular, serve for operation of rope winches in lifeboat launching systems mounted on ships and offshore platforms.
There are a number of lifeboat launching systems for ships and offshore platforms, using rope winches allowing a lifeboat to descend automatically by unwinding the rope on a drum after the rope winch has been unlocked. On offshore platform systems, a lifeboat usually descends vertically into the water; on ships, it usually is moved outside the ship's board by a davit, and then it is vertically lowered into the water, along its side.
Such solutions, however, do not allow to examine any potential failure of the rope winch until it is unlocked or until a lifeboat is lowered into the water.
The invention has a specific advantage in that it allows to engage the rope winch lock while a lifeboat is being pulled up, and, if there is any rope winch failure, such failure may be examined and repaired without any need to secure a lifeboat or lower it into the water.
The invention also increases safety of any tests of the lifeboat launching systems for ships and offshore platforms using rope winches, namely, it allows to test moving a lifeboat from its original position to a position indicated by a rope winch drum lock.
The device for locking rope winch has been shown in the following figures:
The device for locking rope winch presented in
The arched cuttings 3 in the wheel 2 controlling the rope drum 1 of the lifeboat rope winch are identical in length and are positioned in equal distance from each other on the arc of the circle which has its centre in the rotation axis of the rope drum 1 of the lifeboat rope winch.
Each separate fixed lug 4 contains two identical holes 5 positioned on the arc of the circle which has its centre in the rotation axis of the rope drum 1 of the lifeboat rope winch.
The length of the arc with its centre in the rotation axis of the rope drum 1 of the lifeboat rope winch, measured between two holes 5 of each lug 4, is more than the length of the arc between arched cuttings 3 and less than the length of the arc of each arched cutting 3. As the rope drum 1 of the rope winch rotates, at least one of the holes 5 in each lug 4 aligns with one of the arched cuttings 3 on the wheel 2 of the rope drum 1 of the rope winch, subsequently allowing to insert the locking bolt 6 if the rope drum 1 of the rope winch has been previously stopped.
The locking bolt 6 is inserted when the rope drum 1 of the rope winch is stopped, first, through one of two holes 5 in the first lug 4, then through one of the arched cuttings 3 on the wheel 2 of the rope drum 1 of the rope winch, and finally through one of two holes 5 in the second lug 4, then it is secured in position with a nut 7 which locks rotational movement of the rope drum 1 of the rope winch.
As the length of the arc with its centre in the rotation axis of the rope drum 1 of the lifeboat rope winch, measured between two holes 5 of each lug 4, is more than the length of the arc between arched cuttings 3 and less than the length of the arc of each arched cutting 3, the use of the locking bolt 6 results in blocking the rotary movement of the rope drum 1 of the rope winch with a delay.
Number | Name | Date | Kind |
---|---|---|---|
4280605 | Papadopoulos | Jul 1981 | A |
4390161 | Nelson | Jun 1983 | A |
5101939 | Sheridan | Apr 1992 | A |
5944150 | Hikari | Aug 1999 | A |
6431482 | Ikuta | Aug 2002 | B1 |
7226038 | Wickstrom | Jun 2007 | B1 |
20060150883 | Gordon | Jul 2006 | A1 |
20140262693 | de Lore | Sep 2014 | A1 |
20180237277 | Key | Aug 2018 | A1 |