Tire Shoulder Block Overhang for Stacking Stability
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Solution Overview
Problem
Conventional tyres with tread portions featuring blocks, designed for rough terrain, collapse when stacked vertically due to lack of contact between side portions, despite recess and protrusion designs.
Innovation Solution
The tyre design includes shoulder blocks with overhanging portions and middle blocks, arranged in a specific pattern to ensure contact and stability when stacked, with shoulder block lengths between 90% to 98% of gap lengths, and overhanging portions extending 10% to 20% of the tread width, providing a trapezoidal ground contact surface and triangular first walls for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If shoulder blocks protrude axially beyond the side portions to improve turning performance on rough terrain, then the tyre's ground contact capability is improved, but the side portions do not contact each other when stacked, causing collapse
Solution Approach 1:
The shoulder block is divided into two functional parts: a ground contact portion that protrudes axially beyond the side portion to provide rough terrain capability, and an overhanging portion that extends circumferentially to engage with adjacent tyres during stacking. This segmentation allows each part to fulfill its specific function without compromise.
Solution Approach 2:
The overhanging portion of one tyre's shoulder block is nested into the gap between adjacent shoulder blocks of the tyre above it during stacking. This nesting arrangement creates mechanical interlocking that prevents collapse while maintaining the axial protrusion needed for ground contact performance.
2Stability of the object's composition
If recess and protrusion are provided on side portions to suppress collapse, then stacking stability is improved, but it is ineffective for tyres with shoulder blocks protruding beyond side portions
Solution Approach 1:
Instead of modifying the side portions to create recess and protrusion as in conventional designs, this invention inverts the approach by creating the stacking engagement feature on the shoulder blocks themselves. The overhanging portion of the shoulder block engages with the gap between adjacent shoulder blocks of the tyre above, reversing the location and mechanism of stacking stability provision.
3Area of stationary object
If shoulder block length is increased to improve ground contact area, then traction on rough terrain is improved, but the tyre becomes more prone to collapse when stacked
Solution Approach 1:
The shoulder block is designed with non-uniform dimensions: the ground contact portion has sufficient length to provide adequate traction area, while the overhanging portion is specifically dimensioned to optimize stacking engagement. This local quality differentiation allows the same component to excel at both ground contact and stacking stability without compromise.
Data Source
AI summary
A tyre includes a tread portion provided with blocks each protruding toward a ground contact surface thereof from a tread bottom surface, and axially spaced side portions each extending from the tread portion to a respective bead portion. The blocks include shoulder blocks spaced. The shoulder blocks each include an overhanging portion located axially outside the corresponding side portion. The overhanging portion includes a pair of first walls extending in substantially parallel with a tyre meridian cross-section. The shoulder blocks have shoulder block lengths which are lengths in the tyre circumferential direction measured between the pair of first walls along the ground contact surface, wherein the shoulder block lengths are shorter than gap lengths which are lengths in the tyre circumferential direction measured on the tread bottom surface between adjacent shoulder blocks.