Tubular Spider Load Indicator With Valve-Based Load Transfer Sensing

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Solution Overview

Problem

Existing load transfer mechanisms in tubular gripping apparatuses, such as spiders, rely on visual confirmation which is prone to errors, and there is a need for a reliable indicator to ensure safe and accurate load transfer.

Innovation Solution

A load transfer indicator assembly is integrated into the tubular gripping apparatus, utilizing a sensor valve, memory valve, and activator arm system to automatically detect and confirm load transfer, ensuring the spider can be safely opened or closed based on weight distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional load indicators are used in spider cranes, then load monitoring is provided, but the indicators add weight and complexity to the mobile lifting installation

Engineering Contradiction:
Improveload monitoring capabilityVSAvoidcomplexity of mobile lifting installation
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The load indicator is integrated into the spider crane structure itself, combining the load monitoring function with the existing structural components. The indicator unit is mounted on the boom or jib, and the display is incorporated into the operator's station, eliminating separate monitoring devices and reducing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The load indicator system serves multiple functions: it displays current load, indicates maximum load capacity, provides visual warnings for approaching limits, and integrates with the crane's control system. This multi-functionality reduces the need for separate monitoring devices and simplifies the overall installation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If detailed load information is provided to the operator, then lifting operation safety is improved, but the information presentation becomes more complex

Engineering Contradiction:
Improvelifting operation safetyVSAvoidinformation presentation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The load indicator uses color-coded visual signals to represent different load conditions: green for safe operating range, yellow for approaching maximum load, and red for excessive load. This color-coding system provides comprehensive safety information in an intuitively understandable format that reduces operator cognitive load and eliminates complex numerical displays.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

Different parts of the interface provide different types of information optimized for their specific function: visual indicators show load status at a glance, numerical displays provide precise measurements when needed, and warning signals highlight critical conditions. This localized information presentation delivers comprehensive safety data without overwhelming the operator with uniform complexity throughout the interface.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4551795B1Spider load indicator
Publication Date: 2026.05.13 WEATHERFORD TECHNOLOGY HOLDINGS LLC
  • EP4551795B1 patent drawingFigure 1
  • EP4551795B1 patent drawingFigure 2
  • EP4551795B1 patent drawingFigure 3A

AI summary

A tubular gripping assembly for handling a tubular includes a housing; a plurality of gripping members for gripping the tubular; a first fluid line for opening the gripping members, the first fluid line having a one-way valve; and second fluid line for closing the gripping members. The tubular gripping assembly also includes an indicator assembly attached to the housing. The indicator assembly has an indicator movable relative to the housing. The indicator assembly also includes a sensor valve configured to open the check valve for fluid communication through the first fluid line in response to relative axial movement between the indicator and the housing.