Valve Handwheel Cap Assembly for Easy Axial Snap-Fit Mounting

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Solution Overview

Problem

Existing handwheel caps for valves are complex to manufacture and difficult to replace, lacking a straightforward mounting mechanism.

Innovation Solution

A cap with a cover wall and axially extending projections that fit into holes on the handwheel core, featuring a corrugated outer profile with bosses, allowing easy installation and a secure fastening mechanism, along with a slot for screwdriver insertion and a flap for correct positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a soft and resilient plastic covering with moulded ribs is used to fix the cap on the handwheel core, then the cap can be secured to the core, but the system becomes complex in shape and manufacturing and the covering cannot be easily replaced

Engineering Contradiction:
Improvecap fixationVSAvoidshape and manufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cap is divided into separate functional elements: a cover wall for coverage, axially extending projections for fastening, and a corrugated outer profile with bosses for structural integrity. These segmented components are integrated into a single mouldable piece that achieves both secure fixation and manufacturing simplicity through plastic deformation during assembly

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The material properties of the plastic cap are utilized to enable easy replacement. The cap is designed to be deformable during insertion (parameter change during assembly) but maintains rigidity during service. The projections are press-fitted into holes through controlled plastic deformation, creating a secure yet replaceable connection

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If a corrugated outer profile with bosses and axially extending projections is used, then the cap can be easily mounted and secured to the core, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvemounting easeVSAvoidmanufacturing simplicity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

Multiple functions are merged into a single cap component: the cover wall provides coverage, the corrugated profile with bosses provides structural strength and grip, and the axially extending projections provide fastening. This consolidation into one mouldable piece simplifies manufacturing compared to assembling multiple separate parts, while maintaining ease of mounting through the integrated design

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If the cover wall covers at least 95% of the upper face of the core, then the operational comfort and grip are enhanced, but the material usage and manufacturing complexity increase

Engineering Contradiction:
Improvegrip and operational comfortVSAvoidcover wall design
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The cover wall is designed to cover at least 95% of the upper face of the core, providing sufficient coverage for operational comfort and grip without requiring complete coverage. This partial coverage approach achieves the functional benefit while reducing material usage and manufacturing complexity compared to a fully enclosing design

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3877134B1Cap for a handwheel
Publication Date: 2022.03.16 ROTAREX SA
  • EP3877134B1 patent drawingFigure 1~2
  • EP3877134B1 patent drawingFigure 3~6
  • EP3877134B1 patent drawingFigure 4~5

AI summary

Enhanced handwheel cap The invention is directed to a handwheel (1) for a valve, comprising: a core (3) for being fastened to a rotating axle of the valve; and a cap (11) positioned on the core (3); the cap (11) comprising a cover wall on an upper face of the core (3), and projections (17A) extending axially from the cover wall into holes (7B) of the core (3), said projections (17A) being configured for being inserted axially into said holes (7B) and thereby fastening the cap (11) to said core (3).