Tire Tread Groove Stone Rejector Structure for Stone Ejection
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Solution Overview
Problem
Pneumatic tires, particularly large truck and bus tires, face issues with stone entrapment in tread grooves, leading to degradation due to repeated impact, which can cut into the tire structure and reduce its strength and life.
Innovation Solution
Incorporation of stone rejectors with raised platforms and protrusions in the tread grooves to prevent stone entrapment by allowing stones to be ejected, using a design that includes circumferentially spaced stone rejectors with angled sidewalls and protrusions to minimize retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional smooth tread grooves are used, then manufacturing is simple and cost-effective, but stones become trapped and cause tire degradation
Solution Approach 1:
The tread groove is segmented into multiple sections with different geometries: a first groove section with a bottom surface, a second groove section with angled sidewalls, and a third groove section with a protrusion. This segmentation creates distinct functional zones that work together to prevent stone entrapment while maintaining manufacturing feasibility through mold-based formation
Solution Approach 2:
The invention transitions from a traditional two-dimensional groove cross-section to a three-dimensional complex geometry by adding angled sidewalls that slope inward and a circumferential protrusion extending from the groove bottom. This dimensional complexity creates multiple surfaces that deflect and eject stones rather than allowing them to settle at the bottom
2Reliability
If larger tread grooves are used to improve traction, then grip is enhanced, but stone entrapment increases leading to more severe degradation
Solution Approach 1:
The angled sidewalls and protrusion are positioned and dimensioned to actively deflect stones away from the groove bottom before they can become trapped and subjected to repeated impact. The geometry creates a preliminary ejection mechanism that counteracts the harmful impact forces before they can degrade the tire structure
Solution Approach 2:
The invention converts the potential harm of large groove dimensions (which normally increase stone entrapment) into a benefit by using the additional space to create angled sidewalls and protrusions that actively eject stones. The larger groove volume is utilized to accommodate the complex geometry needed for stone rejection rather than simply increasing traction capability
Data Source
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AI summary
Disclosed herein, a pneumatic tire having a tread portion is described. The tread portion includes a generally circumferentially extending groove defined therein. The groove has a groove cross-section defined by a groove bottom, a first groove sidewall, and a second groove sidewall. The second groove sidewall is opposite and substantially parallel to the first groove sidewall. The groove has a groove width defined between the first groove sidewall and the second groove sidewall. A plurality of stone rejectors extend between the first groove sidewall and the second groove sidewall. Each stone rejector in the plurality of stone rejectors is circumferentially spaced from an adjacent stone rejector. Each stone rejector includes a raised platform and a protrusion. The raised platform extends axially from the first groove sidewall to the second groove sidewall. The protrusion extends from a top surface of the raised platform.