Locking mechanism

Abstract

A device for heave compensation of a tool unit that is suspended via one or more wires from a mast mounted on a platform, each wire at a first end being attached to the mast via an attachment and running via a first heave compensation unit, and each wire at a second end being attached to a second heave compensation unit that is connected to the tool unit. The second heave compensation unit includes a movable compensation mechanism, which at its first end is attached to the wire and which at its second end is attached to the tool unit. The second heave compensation unit includes a releasable locking device with which the motions of the compensation mechanism can be selectively prevented and allowed.

1 . A device for heave compensation of a tool unit that is suspended via one or more wires from a mast mounted on a platform, each wire at a first end being attached to the mast via an attachment and running via a first heave compensation unit, and each wire at a second end being attached to a second heave compensation unit that is connected to the tool unit,
 wherein the second heave compensation unit comprises a movable compensation mechanism, which at its first end is attached to the one or more wires and which at its second end is attached to the tool unit, and the second heave compensation unit comprises a releasable a locking device with which the motions of the compensation mechanism can be selectively prevented and allowed.   
     
     
         2 . The device as disclosed in  claim 1 , wherein the compensation mechanism is attached to the one or more wires via a connecting unit and is attached to the tool unit via a link element, and wherein the connecting unit and the link element are movable in relation to one another, and wherein the releasable locking device is movable for selectively and releasably limiting the motions of the connecting unit and the link element in relation to one another. 
     
     
         3 . The device as disclosed in  claim 2 , wherein the releasable locking device comprises a locking bolt with a central, narrowed portion and broad shoulder portions at each end of the bolt. 
     
     
         4 . The device as disclosed in  claim 2 , wherein the link element comprises a through hole with a first portion and a second portion, the first portion having a larger opening than the second portion. 
     
     
         5 . The device according to  claim 4 , wherein the first portion has a dimension that allows passage of the shoulder portions whilst the second portion has a dimension that does not allow passage of the shoulder portions but does allow passage of the central portion. 
     
     
         6 . The device according to  claim 4 , wherein the first portion has a circular cross section and the second portion is elongate. 
     
     
         7 . The device as disclosed in  claim 1 , wherein said one or more wires between the second heave compensation unit and the first heave compensation unit runs via guide pulleys which are mounted at an upper portion of the mast, and run via the first heave compensation unit between the guide pulleys and the attachment in the mast. 
     
     
         8 . The device as disclosed in  claim 1 , wherein the first heave compensation unit is connected at a first end to the platform and at a second end is movably attached to the one or more wires via reversing pulleys and a cylinder. 
     
     
         9 . The device as disclosed in  claim 1 , comprising a locking mechanism with which the motions of the compensation units can selectively be prevented and the compensation units transfer loads between the tool unit and the one or more wires as substantially rigid bodies. 
     
     
         10 . The device as disclosed in  claim 1 , wherein the first heave compensation unit functions as an active heave compensator whilst the second heave compensation unit functions as a passive heave compensator. 
     
     
         11 . The device as disclosed in  claim 3 , wherein the link element comprises a through hole with a first portion and a second portion, the first portion having a larger opening than the second portion. 
     
     
         12 . The device according to  claim 5 , wherein the first portion has a circular cross section and the second portion is elongate. 
     
     
         13 . The device as disclosed in  claim 2 , wherein the first heave compensation unit is connected at a first end to the platform and at a second end is movably attached to the one or more wires via reversing pulleys and a cylinder. 
     
     
         14 . The device as disclosed in  claim 2 , comprising a locking mechanism with which the motions of the compensation unit scan selectively be prevented and the compensation units transfer loads between the tool unit and the one or more wires as substantially rigid bodies. 
     
     
         15 . The device as disclosed in  claim 3 , comprising a locking mechanism with which the motions of the compensation unit scan selectively be prevented and the compensation units transfer loads between the tool unit and the one or more wires as substantially rigid bodies. 
     
     
         16 . The device as disclosed in  claim 4 , comprising a locking mechanism with which the motions of the compensation unit scan selectively be prevented and the compensation units transfer loads between the tool unit and the one or more wires as substantially rigid bodies. 
     
     
         17 . The device as disclosed in  claim 5 , comprising a locking mechanism with which the motions of the compensation unit scan selectively be prevented and the compensation units transfer loads between the tool unit and the one or more wires as substantially rigid bodies. 
     
     
         18 . The device as disclosed in  claim 6 , comprising a locking mechanism with which the motions of the compensation unit scan selectively be prevented and the compensation units transfer loads between the tool unit and the one or more wires as substantially rigid bodies. 
     
     
         19 . The device as disclosed in  claim 7 , comprising a locking mechanism with which the motions of the compensation unit scan selectively be prevented and the compensation units transfer loads between the tool unit and the one or more wires as substantially rigid bodies. 
     
     
         20 . The device as disclosed in  claim 8 , comprising a locking mechanism with which the motions of the compensation unit scan selectively be prevented and the compensation units transfer loads between the tool unit and the one or more wires as substantially rigid bodies.