Conical Grab Bar Assembly for Tolerance-Compensating Mounting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing grab bar assemblies for passenger transport vehicles are bulky and require multiple connecting bolts, making them difficult to assemble and unable to compensate for manufacturing tolerances effectively.

Innovation Solution

A support rod arrangement with a conical connection between the grab bar element and the base, allowing for 360° rotation and alignment, and a detachable or permanent connection to the vehicle body, which compensates for manufacturing tolerances and provides a quick-assembly interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a bolted connection with multiple connecting bolts is used, then the connection strength is improved, but the device complexity and assembly difficulty increase

Engineering Contradiction:
Improveconnection strengthVSAvoiddevice complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent combines multiple connecting bolts into a single conical connection interface. The conical connection integrates the functions of multiple fasteners into one unified structure, reducing the number of components while maintaining connection strength through the conical geometry that distributes loads effectively across the interface.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The conical connection is segmented into a conical male part and a conical female receptacle, allowing for easy assembly and disassembly. This segmentation enables the connection to be made without complex preparatory work while maintaining structural integrity through the tapered interface design.

Inventive Principle:
Principle #1Segmentation

2Strength

If a bolted connection with multiple connecting bolts is used, then the connection strength is improved, but the ease of assembly deteriorates

Engineering Contradiction:
Improveconnection strengthVSAvoidease of assembly
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

Multiple assembly steps and multiple bolts are merged into a single conical insertion operation. The conical connection allows the grab bar element to be attached to the base by simply inserting one component into another, eliminating the need for multiple fastening operations while maintaining connection strength.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The conical geometry is pre-designed to guide the assembly process automatically. The tapered shape provides self-alignment and self-centering during insertion, eliminating the need for precise alignment procedures or preparatory work before assembly.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If a fixed rigid connection is used, then the structural stability is improved, but the ability to compensate for manufacturing tolerances deteriorates

Engineering Contradiction:
Improvestructural stabilityVSAvoidtolerance compensation
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The conical connection introduces a degree of rotational freedom, allowing the grab bar element to rotate 360° around the vertical axis during assembly. This dynamic capability enables the connection to adapt to manufacturing tolerances in the vehicle body while maintaining structural stability once positioned.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The conical geometry changes the interaction parameters between components by providing a tapered surface that converts radial misalignment into axial displacement. This parameter transformation allows the connection to accommodate tolerance variations while maintaining a stable fixed position after assembly.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If a conical connection with shallow angle is used, then the ease of disassembly is improved, but the force transmission capability deteriorates

Engineering Contradiction:
Improveease of disassemblyVSAvoidforce transmission
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The conical connection parameters (angle, length, diameter) are optimized to achieve a balance between ease of disassembly and force transmission. The specific cone angle and dimensions are selected to provide sufficient surface area for force distribution while maintaining a shallow enough angle for easy removal without special tools.

Inventive Principle:
Principle #35Parameter changes

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

The conical connection enables a compact, easily assembled, and ergonomically designed grab bar system that can transmit large torques and forces while being adjustable and easy to install, without requiring additional preparatory work like drilling or riveting.

Implementation Method 1

The contacting surfaces of the tapered connection have the shape of a truncated cone... The cone ratio is crucial for the ease of disassembly of the connection... The conical connection enables the transmission of large, alternating, and sudden torques and forces

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4671079A1Retaining rod assembly
Publication Date: 2025.12.31 SIEMENS MOBILITY GMBH
  • EP4671079A1 patent drawingFigure 1
  • EP4671079A1 patent drawingFigure 2
  • EP4671079A1 patent drawingFigure 3

AI summary

The invention relates to a support rod arrangement 10, in particular for a passenger transport vehicle 1, comprising a base 100 and a support rod element 200 with at least one support rod 230, wherein the support rod element 200 is attached to the base 100, wherein the support rod element 200 and the base 100 are connected via a conical connection 300.