Tyre-Changing Hooked End Rotation for Low-Stress Bead Removal

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Solution Overview

Problem

Existing tyre-changing machines stress the bead edge of the tyre excessively during removal due to limited movement of the hooked end, which can hinder smooth operation and increase the effort required for disassembly.

Innovation Solution

A tyre-changing machine with a hooked end that can passively rotate around its axis perpendicular to the wheel's axis of rotation, allowing it to adapt to friction forces and reduce stress on the bead edge by changing its inclination during wheel rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the hooked end is fixed relative to the tool holding arm, then the structure is simple and robust, but the bead edge is subjected to excessive stress during wheel rotation

Engineering Contradiction:
Improvestress on bead edgeVSAvoidcomplexity of hooked end mechanism
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The hooked end is made rotatable around an axis perpendicular to the wheel's axis of rotation, transforming it from a fixed static component to a dynamic one that can adapt its orientation during wheel rotation. This rotational freedom allows the hooked end to passively adjust its inclination in response to friction forces, thereby reducing stress on the bead edge while maintaining structural simplicity

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If the hooked end is movable locked together with the tool holding arm, then radial forces can be exerted to space the bead apart from the rim, but the hooked end cannot adapt to changing friction forces during rotation

Engineering Contradiction:
Improvestress on bead edgeVSAvoidadaptability to friction forces
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The hooked end is designed with rotational freedom around an axis perpendicular to the wheel's axis, enabling it to dynamically adjust its inclination in response to varying friction forces during wheel rotation. This passive adaptation mechanism allows the hooked end to optimize its interaction with the bead throughout the rotation cycle, reducing stress while maintaining the ability to exert radial forces when needed

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the hooked end moves only within a vertical plane passing through the wheel axis, then the movement is simple and controlled, but the smoothness of operation on the bead is limited

Engineering Contradiction:
Improvesmoothness of bead removalVSAvoidmovement mechanism of hooked end
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The hooked end is granted rotational freedom around an axis perpendicular to the wheel's axis of rotation, adding a new dimension of movement beyond the traditional vertical plane. This additional rotational degree of freedom allows the hooked end to passively adapt its orientation in response to friction forces, significantly improving the smoothness of bead removal while keeping the mechanism relatively simple

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution enables a more delicate and efficient removal of the tyre bead with reduced stress, facilitating faster and easier disassembly operations while minimizing operator effort.

Implementation Method 1

the possibility of passively adapting its inclination depending on the increase or decrease in the friction forces normally created when the wheel is rotated between the bead itself and the hooked end

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4065391B1Tyre-changing machine
Publication Date: 2024.03.13 SICAM SRL
  • EP4065391B1 patent drawingFigure 1
  • EP4065391B1 patent drawingFigure 2
  • EP4065391B1 patent drawingFigure 3a~3b

AI summary

The present invention concerns a tyre-changing machine (1) provided with a basic structure (2) that can rest on the ground, a retaining and rotation unit (3) mounted on an upper part of the structure (2) and adapted to retain and set the rim (C) of a wheel (R) in rotation around an axis of rotation of the wheel (Z-Z) and a holding column (7) associated with the retaining and rotation unit (3) and intended to support a tool (8) for mounting/disassembling a tyre (P) onto/from the rim (C) of the wheel (R). Advantageously, the tool (8) comprises a hooked end (9) which can rotate passively around an axis of rotation (X-X) orthogonal to the axis of rotation of the wheel (Z-Z).