Compliant Coil Form for Magnetic Flowmeter Saddle Winding

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Solution Overview

Problem

Existing methods for manufacturing saddle coils for magnetic flowmeters are cumbersome due to the use of tape and conventional mechanical fasteners, which can wear away and pose a risk of electrical shorting, and require complex bending processes.

Innovation Solution

A coil assembly with a coil form featuring spaced support members and a loop-shaped base, allowing the winding to be wrapped in a flat orientation and bent to a saddle shape using kerf cuts and bendable tabs, eliminating the need for additional clamps and providing secure fastening to an installation location.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If tape and conventional mechanical fasteners are used to secure the winding, then the winding is protected from wear and electrical shorting, but the manufacturing process becomes cumbersome and complex

Engineering Contradiction:
Improveprotection from wear and electrical shortingVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coil form integrates both support functions (holding the winding in place) and fastening functions (securing to the pipe) into a single structural component. The support members extend from the base to contact and hold the winding, while the base itself provides the mounting interface for securing to the pipe, eliminating the need for separate tape and clamp components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coil form serves multiple functions simultaneously: it provides structural support for the winding, acts as a mounting interface for pipe attachment, and integrates fastening features (holes for fasteners) directly into its structure. This multi-functional design replaces multiple separate components with a single versatile element.

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

2Reliability

If tape is used to cover and protect the winding, then electrical insulation is maintained, but the tape wears away over time and poses a risk of shorting

Engineering Contradiction:
Improveelectrical insulationVSAvoidservice life of protective covering
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The protective and support functions previously performed by external tape are extracted and integrated directly into the coil form structure. The support members provide mechanical support and protection to the winding, eliminating the need for separate protective tape that would wear away over time.

Inventive Principle:
Principle #2Taking out (Extraction)

3Strength

If conventional mechanical fasteners are used to secure the coil to the pipe, then secure mounting is achieved, but additional clamps and fasteners increase device complexity

Engineering Contradiction:
Improvemounting securityVSAvoidnumber of fastening components
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The fastening function is merged into the coil form base structure itself. The base includes integrally formed holes that directly receive fasteners, combining the mounting interface and fastening features into the primary structural element rather than requiring separate clamps and mounting brackets.

Inventive Principle:
Principle #5Merging (Combining)

4Shape

If the winding is bent to a saddle shape after wrapping, then the desired coil geometry is achieved, but the bending process becomes complex and difficult

Engineering Contradiction:
Improvesaddle shape geometryVSAvoidbending process difficulty
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The coil form is pre-shaped with the desired saddle geometry before the winding is applied. By forming the support members and base into the final saddle shape in advance, the winding naturally assumes this geometry when wrapped around the form, eliminating the need for complex post-wrapping bending operations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2467859B1Compliant coil form
Publication Date: 2019.01.09 ROSEMOUNT INC
  • EP2467859B1 patent drawingFigure 1~2
  • EP2467859B1 patent drawingFigure 3
  • EP2467859B1 patent drawingFigure 4

AI summary

A coil assembly (20) includes a coil form (22; 22A-22D) and a winding (24). The coil form (22; 22A-22D) includes a base (26) defining a loop defined by a pair of opposed first sides and a pair of opposed second sides, a plurality of spaced apart support members (30; 30A-30D) extending from the base (26) along the first sides, and a coil support structure (28A, 28B) extending from the base (26) at each of the second sides. Each support member (30; 30A-30D) includes a first portion (32) and a second portion (34), the first portion (32) extending from the base (26) and the second portion (34) extending from the first portion (32), with a gap defined between adjacent support members (30; 30A-30D). The winding (24) abuts the first portion (32) of at least some of the spaced apart support members (30; 30A-30D) and is at least partially secured by the second portions (34) of the support members (30; 30A-30D). The winding (24) abuts each of the coil support structures (28A, 28B), and is curved in a saddle shape.