Tapered Nut Valve Plug Assembly for Interchangeable Stem Sizes

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Solution Overview

Problem

Conventional fluid valves require a large number of differently designed components, leading to increased manufacturing and inventory costs due to varied thread sizes and counts among valve stems and plugs, limiting their interchangeability and causing complexity in assembly and management.

Innovation Solution

A tapered nut valve plug fastener system that uses a valve plug with a large central bore to accommodate various valve stem diameters, where a nut with a tapered surface centralizes and secures the stem, preventing leakage and allowing for multiple stem diameters to be used with a single plug, and additional tapered or radiused surfaces enhance compatibility and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional fluid valves use varied thread sizes and counts among valve stems and plugs, then each valve can be precisely designed for its specific application, but the number of differently designed components increases, leading to increased manufacturing and inventory costs

Engineering Contradiction:
Improveapplication-specific design capabilityVSAvoidnumber of differently designed components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The valve plug is designed with a universal unthreaded central bore that can accommodate multiple valve stem diameters, and a standardized threaded bore that accepts various nuts. This allows a single valve plug design to serve multiple applications by simply changing the valve stem and nut combination, eliminating the need for differently designed valve plugs for each application.

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

Solution Approach 2:

The valve assembly is segmented into interchangeable components: the valve plug body remains constant, while the valve stem and nut are separate replaceable parts. This segmentation allows the standardized valve plug to work with different valve stem diameters by simply swapping the stem and nut components, reducing the need for multiple specialized valve plug designs.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If conventional fluid valves use standardized components, then manufacturing and inventory costs decrease, but the ability to accommodate various valve stem diameters and thread specifications is limited

Engineering Contradiction:
Improvecomponent standardizationVSAvoidaccommodation of various stem diameters
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The unthreaded central bore of the valve plug acts as an intermediary element that receives and accommodates valve stems of various diameters. This intermediary structure allows the standardized valve plug to interface with non-standardized valve stems without requiring the plug itself to be customized for each stem size.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The valve plug design changes the parameter of the central bore from threaded to unthreaded, allowing it to accommodate a range of valve stem diameters through clearance fit rather than threaded engagement. This parameter change enables a single plug design to work with multiple stem sizes by varying only the stem and nut parameters.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If multiple valve stem diameters are accommodated with different threaded engagements, then each stem can be precisely fitted, but the assembly process becomes more complex and time-consuming

Engineering Contradiction:
Improvethreaded engagement precisionVSAvoidassembly time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The standardized threaded bore and nut combination provides a universal engagement mechanism that works with all valve stems regardless of diameter. This eliminates the need for different threaded engagement methods for different stem sizes, allowing assembly workers to use the same procedure for all stems and reducing assembly time.

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

Solution Approach 2:

The threaded engagement function is extracted from the valve plug body and placed in the separate nut component. This allows the valve plug to have a universal unthreaded bore, while the threaded engagement is handled by interchangeable nuts that can be quickly screwed onto the standardized threaded bore, speeding up the assembly process.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If conventional valves require precise threaded matches between stems and plugs, then connection reliability is high, but the number of part numbers and inventory requirements increase

Engineering Contradiction:
Improveconnection reliabilityVSAvoidnumber of part numbers
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The standardized threaded bore with standardized nuts creates a universal connection system that maintains reliable threaded engagement while working with valve stems of various diameters. This single standardized connection system replaces multiple specialized threaded match combinations, reducing the number of part numbers from potentially dozens to just a few standard sizes.

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

Solution Approach 2:

The connection system is segmented into the standardized threaded bore in the plug and the separate standardized nut, allowing the reliable threaded engagement to be maintained while the valve stem itself remains a separate interchangeable component. This segmentation enables one plug design to work with multiple stem sizes without compromising connection reliability.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3596365B1Tapered nut valve plug fasteners
Publication Date: 2021.11.24 FISHER CONTROLS INT LLC
  • EP3596365B1 patent drawingFigure 1
  • EP3596365B1 patent drawingFigure 2
  • EP3596365B1 patent drawingFigure 3

AI summary

Example tapered nut valve plug fastener apparatus disclosed herein include a valve stem, a first nut, a valve plug, and a second nut. The first nut includes a first tapered surface and the second nut includes a second tapered surface. The valve plug includes a bore. The first nut threadably engages the valve stem and the valve stem passes through the bore. The bore engages the first tapered surface. The second nut threadably engages the valve stem and the bore engages the second tapered surface. Example tapered nut valve plug fastener apparatus disclosed herein include a valve stem, a first nut, a valve plug, and a second nut. The first nut includes a first tapered surface and the second nut includes a second tapered surface. The valve plug includes a bore. The first nut threadably engages the valve stem and the valve stem passes through the bore. The bore engages the first tapered surface. The second nut threadably engages the valve stem and the bore engages the second tapered surface.