Tire Mounting Bar with Composite Soft Material for Rim Protection
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Solution Overview
Problem
Existing tire mounting and demounting tools cause marring and discoloration of wheel rims due to their hard materials and single-point contact, which is aesthetically undesirable for vehicles where wheel appearance is important.
Innovation Solution
A tire mounting and demounting bar with two ends, one with a rectangular head for demounting and another with parallel round heads for mounting, both made of a softer material like polypropylene to prevent rim damage, featuring tapered necks and a riveted connection for strength and ease of use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If steel spoons are used for tire mounting and demounting, then the tools provide sufficient strength and leverage, but the hard steel material causes marring and discoloration of wheel rims
Solution Approach 1:
The tool combines a steel core for structural strength with a polyethylene outer layer that contacts the rim. This composite structure provides both the necessary mechanical strength for tire manipulation and a soft contact surface that prevents rim marring and discoloration.
Solution Approach 2:
The tool has different material properties in different regions: the core maintains high strength throughout, while only the outer surface that contacts the rim is made soft. This localized differentiation allows the tool to provide strength where needed while being gentle on the rim surface.
2Ease of operation
If steel spoons with single-point contact are used, then the tools can manipulate the bead effectively, but the concentrated contact pressure causes abrasion and damage to the rim surface
Solution Approach 1:
The contact surface is segmented into multiple lobes rather than a single point. This distribution of contact points reduces the pressure concentration on any single area of the rim, preventing abrasion while maintaining effective bead manipulation capability.
Solution Approach 2:
The tool features rounded lobes instead of sharp edges or flat surfaces. The curved, spherical-like contact surfaces distribute pressure more evenly and reduce stress concentration, allowing effective bead manipulation without causing rim abrasion or damage.
3Force
If hard steel tools are used for tire changing, then the tools can apply sufficient force to manipulate the bead, but the hardness causes discoloration and rust on ferrous rims
Solution Approach 1:
The tool uses a steel core to generate and transmit high forces for bead manipulation, while the polyethylene outer layer acts as a protective interface that prevents direct contact between the hard steel and the rim, thereby avoiding discoloration and rust.
Solution Approach 2:
The polyethylene outer layer serves as an intermediary between the steel core and the rim. It transmits the force generated by the steel core to manipulate the bead while protecting the rim from direct contact with the hard steel, preventing discoloration and corrosion.
Data Source
AI summary
A manual tool has a handle with two opposite ends that mount and demount a tire from a wheel. The first end has a rounded rectangular head for inserting between the bead and rim, when demounting a tire from a wheel. The second end is at an angle to the first end and has two spaced apart and parallel round heads that also insert between the rim and the bead, for mounting a tire. The tool, when either end is engaged between a bead and a wheel, is rotated about the axis of the wheel to mount or to demount a tire. The first end and the second end are made of a material of lesser hardness than a wheel thus preventing marring of the wheel.