Oversized Hole Plug Connection for Drilling Mast Alignment

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Solution Overview

Problem

Existing drilling rig mast assembly methods are inefficient, particularly in aligning and securing mast sections during erection, often requiring costly and labor-intensive crane operations due to alignment issues with pin holes and removable pins.

Innovation Solution

A pinned structural connection system using oversized holes and removable plugs in the drilling rig mast support shoes, allowing for easier alignment and secure attachment of mast sections with circular pins, facilitating efficient assembly and erection by reducing alignment complexities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional pin holes and removable pins are used for connecting mast sections, then the connection strength is maintained, but the alignment process becomes labor-intensive and time-consuming requiring crane operations

Engineering Contradiction:
Improvealignment processVSAvoidassembly time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent changes the dimensional parameter of the hole from a standard size to an oversized hole. This parameter change allows for easier alignment of mast sections during assembly, reducing the need for precise positioning and crane operations, thereby decreasing assembly time and labor intensity while maintaining connection strength through the subsequent insertion of the removable pin and plug system.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The oversized hole is prepared in advance during manufacturing, creating a tolerance buffer that facilitates alignment during the assembly process. This preliminary action eliminates the need for complex alignment procedures and heavy equipment during field assembly, directly addressing the time and labor efficiency problem.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If oversized holes are used to simplify alignment, then the ease of assembly is improved, but the structural precision and pin fit may be compromised

Engineering Contradiction:
Improveassembly simplicityVSAvoidpin hole alignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The connection system is segmented into multiple components: the oversized hole in the support shoe, the removable pin, and the plug. This segmentation allows the oversized hole to provide alignment tolerance while the pin and plug components work together to establish precise positioning and maintain structural integrity, thus resolving the contradiction between ease of assembly and manufacturing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The removable pin acts as an intermediary element between the oversized hole and the mast section connection. It bridges the tolerance gap created by the oversized hole while maintaining precise positioning, allowing easy alignment during assembly without compromising the final structural precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If conventional assembly methods are used, then structural integrity is maintained, but the cost and labor requirements increase significantly

Engineering Contradiction:
Improveconnection reliabilityVSAvoidassembly efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system employs a dynamic assembly process where the oversized hole provides initial alignment flexibility, the removable pin establishes the connection, and the plug secures the position. This dynamic sequence allows for efficient assembly operations while maintaining reliable structural connections, improving productivity without sacrificing connection reliability.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2751370B1Pinned structural connection using a pin and plug arrangement
Publication Date: 2015.07.08 NAT OILWELL VARCO LP
  • EP2751370B1 patent drawingFigure 1A~1B
  • EP2751370B1 patent drawingFigure 1C~1D
  • EP2751370B1 patent drawingFigure 1E~1F

AI summary

Generally, the subject matter disclosed herein is directed to, among other things, systems and methods for making up pivotably pinned structural connections that may be used for erecting drilling rig masts. One illustrative system includes a drilling rig mast having at least one support leg, a drilling rig mast support having at least one mast support shoe, and a pinned connection between the at least one support leg and the at least one mast support shoe. Additionally, the pinned connection of the disclosed system includes a pin, an oversized hole having at least a first hole portion, and a removable plug that is adapted to be inserted into the oversized hole, wherein the removable plug has at least a first plug surface portion, and wherein the first hole portion and the first plug surface portion define at least part of a pin hole that is adapted to receive the pin.