Pipe Gripper Holding Device Service Position Die Replacement
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Solution Overview
Problem
Existing gripper systems for pipes face risks of errors and mistakes during die replacement, leading to potential equipment damage and loose parts falling into boreholes during drilling or seabed operations.
Innovation Solution
A gripper design with a holding device that can be moved to a service position, where it is partially emerged from a countersunk depression, allowing for secure die replacement without complete removal from the gripping body, and an elongated fixing device that supports the holding device in this position, reducing the risk of mistakes and equipment damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the holding device is completely removed from the gripping body during die replacement, then the die can be replaced, but the risk of the holding device being dropped into the borehole increases
Solution Approach 1:
The holding device is segmented into a movable portion and a fixed portion. The movable portion can be displaced to a service position where it is partially emerged from the countersunk depression, allowing die replacement while remaining supported by the gripping body. This segmentation enables the holding device to be accessed for maintenance without complete removal, thus preventing the risk of dropping while facilitating die replacement.
Solution Approach 2:
The countersunk depression acts as an intermediary structure that provides a transition zone between the fully recessed operation position and complete removal. The movable portion of the holding device can be partially emerged into this depression, providing a stable intermediate position that facilitates die replacement while maintaining support and preventing accidental drops into the borehole.
2Reliability
If the holding device is held by the gripping body in the service position, then the risk of mistakes during die replacement is reduced, but the holding device cannot be completely removed when needed
Solution Approach 1:
The connection arrangement provides dynamic positioning capability for the holding device. The movable portion can be displaced between the operation position (fully recessed), service position (partially emerged and held by gripping body), and completely removed position. This dynamic design allows the system to adapt to different operational needs: stable positioning during normal operation, supported positioning during die replacement, and complete removal when necessary, thus resolving the contradiction between error reduction and removal capability.
3Strength
If the holding device is countersunk into a depression in the gripping body, then lateral forces are effectively transferred, but the holding device cannot be easily accessed for maintenance
Solution Approach 1:
The holding device incorporates a movable portion that can be dynamically displaced from the countersunk depression to a service position. During normal operation, the holding device is fully recessed, allowing effective transfer of lateral forces to the gripping body. During maintenance, the movable portion can be displaced outward to the service position where it is partially emerged and easily accessible, thus resolving the contradiction between strength and accessibility.
Solution Approach 2:
The holding device is segmented into fixed and movable portions. The fixed portion remains countersunk in the depression to maintain structural integrity and lateral force transfer capability, while the movable portion can be displaced for maintenance access. This segmentation allows the system to simultaneously achieve both strong lateral force transfer and easy accessibility during maintenance operations.
Data Source
Figure 1
Figure 2a~2c
Figure 3a~4
AI summary
A gripper (1) for gripping a pipe (P) is presented, comprising gripping bodies (101) and holding devices (2), and dies (3), the dies being fastened to respective holding devices (2) and the holding devices being fastened to respective gripping bodies with respective connection arrangements (4). The connection arrangements (4) is adapted to be maneuvered so as to release the respective holding device (2) from an operation position so as for the holding device to assume a service position in which it is held by the respective gripping body. A die locking device (202) of a holding device (2) is adapted to be kept, by contact with the respective gripping body (101), in a locking position when holding device (2) is in the operation position. The locking device (202) is free to move to an open position when the holding device (2) is moved away from the operation position. The die (3) and a seat (203) for the die in the holding device (2) are provided a notch (303) and a protrusion (208), arranged so that, as the pipe contacting element is inserted into the seat in an insertion direction (B), the protrusion enters, in parallel with the insertion direction, into the notch.