Cylindrical Signaling Device Assembly with Conical Thread Projections

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Solution Overview

Problem

Existing cylindrical lighting or display devices in holders or housings face issues with unreliable assembly and mechanical stability due to the elastic deformation of fastening rings with segmented external threads, leading to slippage and twisting during assembly and disassembly.

Innovation Solution

The fastening ring's external thread is designed with conical tongue-like projections that radially fix the insert upon screwing, preventing elastic deformation and ensuring secure engagement, with an asymmetric thread design that allows for easy assembly and disassembly without additional tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the fastening ring uses a segmented external thread on tongue-like projections for easy assembly and manufacturing, then assembly speed is improved, but mechanical stability deteriorates due to elastic deformation causing slippage and twisting

Engineering Contradiction:
Improveassembly speedVSAvoidmechanical stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the geometric parameters of the tongue-like projections by adding a conical section with a specific angle (α) between 15° and 45°. This parameter change transforms the projections from purely elastic to a combination of elastic and rigid behavior, preventing slippage while maintaining assembly ease. The conical angle is the critical parameter that resolves the contradiction between assembly speed and mechanical stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces asymmetry through the conical section on the tongue-like projections, creating a directional geometry that prevents backward movement. The asymmetric conical shape allows easy insertion in one direction while providing mechanical locking against reverse forces, thus maintaining both assembly speed and reliability.

Inventive Principle:
Principle #4Asymmetry

2Ease of operation

If the fastening ring uses a segmented external thread for quick assembly, then assembly effort is reduced, but the insert can be pushed out by axial forces due to elastic deformation

Engineering Contradiction:
Improveassembly effortVSAvoidresistance to axial forces
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

By modifying the geometry of the tongue-like projections to include a conical section with angle α between 15° and 45°, the patent changes the mechanical properties from purely elastic to a hybrid elastic-rigid structure. This parameter change enables the projections to resist axial forces while still allowing easy assembly with reduced effort.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The conical section on the tongue-like projections provides preliminary anti-action by creating a mechanical barrier against axial forces before they can cause slippage. The conical geometry pre-establishes a locking mechanism that counteracts the tendency of the insert to be pushed out, maintaining strength without increasing assembly effort.

Inventive Principle:
Principle #9Preliminary anti-action

3Ease of manufacture

If the fastening ring uses a segmented external thread on crown-like projections, then manufacturing is simplified for demoulding, but the thread engagement becomes unreliable due to elastic deformation

Engineering Contradiction:
Improvedemoulding capabilityVSAvoidthread engagement accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent maintains the segmented structure for ease of manufacture and demoulding, but changes the geometric parameters by adding a conical section with angle α between 15° and 45°. This parameter modification ensures that the projections remain manufacturable while achieving reliable thread engagement without elastic deformation-induced slippage.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent retains the segmented structure of the external thread on tongue-like projections, which facilitates manufacturing and demoulding. By combining this segmentation with the conical section, the patent achieves both ease of manufacture and reliable thread engagement, as the segments can be easily formed while the conical geometry ensures precise engagement.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design enhances the reliability and mechanical stability of the assembly process, preventing slippage and twisting, while maintaining ease of assembly and disassembly, without increasing costs or effort.

Implementation Method 1

the fastening ring does not have its external thread on a completely formed cylinder jacket, but on a series of tongues which are designed like a crown in the axial direction and in radial direction can deflect elastically inwards

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the thread is designed asymmetrically, whereby the rear flanks (seen in the assembly direction) can be very steep, depending on the manufacturing process and the resulting limits, up to 90 °, thus normal to the screw axis

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Data Source

PatentEP3203137B1Assembly of a cylindrical signaling device in a holder
Publication Date: 2018.11.21 SWARCO FUTURIT VERKEHRSSIGNALSYSTEME GES MBH
  • EP3203137B1 patent drawingFigure 1
  • EP3203137B1 patent drawingFigure 2
  • EP3203137B1 patent drawingFigure 3

AI summary

The invention relates to a light source or signaling device housed in an insert (2) with a substantially cylindrical outer shape, which can be mounted in a corresponding receptacle of a holder or housing (1). The holder or housing (1) has a cylindrical collar with an internal thread (6) into which the insert (2) is inserted and secured by means of a retaining ring (3) with an external thread (5) by screwing the two threads (5, 6) together. To improve the fixation and facilitate assembly, the external thread (5) is provided on tongue-shaped, axial projections (4) of the retaining ring (3).