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IP.com Disclosure Number: IPCOM000249049D
Publication Date: 2017-Jan-30
Document File: 7 page(s) / 707K

Publishing Venue

The IP.com Prior Art Database

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 51% of the total text.





[0001] A connector clamp is often used in subsea applications. For example, a CVC

connector or a CHC connector may be used to join separate sections of production tubing

together. Given the subsea environment, securing and setting the clamp in place in a

permanent fashion is of critical importance. The backing up of the lead screw that is

used to set the clamp at the outset could lead to clamp failure with potentially catastrophic

consequences. Therefore, embodiments of secondary locks and techniques are detailed

herein that uniquely prevent backlash or backing up of the lead screw.

[0002] Alternative efforts have been undertaken to help prevent some of the backlash

in the lead screw. For example, the Vector Double Lock here depicts a double lock type

of device that clamps down on a lead screw (at the top of the picture). However, some

relaxation of the lock on the screw emerges over time.


[0003] The Vector-type of clamp utilizes a secondary lock that allows backing of the

screw due to the lack of a backlash elimination function. This is inherent due to the

incremental nature of the lock utilizing gear-like components.

[0004] A Freudenberg plug as depicted below will allow for losing about 30% of the

preload imparted on the set screw again due to the incremental nature in which the lock

is set.

[0005] With this particular device, there are 30 teeth. Given 360°, this means that up

to 12° degrees of loosening is possible with the device in place which translates to the

potential loss of 30% of the pre-load. However, as illustrated here, these efforts are



[0006] However, the embodiments described below, include an infinitely more

accurate set due to the allowance of locking at any position. That is, the locking is not

reliant on incremental predetermined positions but rather may truly lock at any position

as detailed below.


[0007] A subsea secondary lock for a clamp connector is proposed that may be used

to uniquely prevent the backing of the clamp’s lead screw, therefore protecting the clamp

connection from loosening. This ROV operated tool will be placed into an ROV buket

or a torque tool interface. The tool may also be manipulated manually on shore. After

setting the lock in the bucket, the manipulator wrist rotation will be used to clamp the

lock. The secondary lock is provided with a feature to eliminate the backlash in the

installation interface. Notice the lock’s position indicator of OPEN-CLOSED at the top

of the tool which is visible to ROV cameras in the figure here.


[0008] The locked position in particular is provided with its own locking feature to

ensure that the lock remains locked. The rotary lock functions to immobilize the lead

screw in any position as the depicted blue projections rotate outward to grab the inner

wall of the bucket. Thus, reverse rotation is not allowed. Some features of the tool may


- Preventing reverse rot...