Asymmetric Tire Stud Design for Pin Retention

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Solution Overview

Problem

Conventional snow tires with stud pins tend to lose stud pins when driven on concrete or asphalt surfaces due to forces applied during driving, braking, and cornering, leading to pin drop and reduced traction, durability, and wear.

Innovation Solution

The stud design features a tip end with a hexagonal-like cross-section, a stump portion with a polygonal shape, and a shank portion with a thinner cross-section, embedded in the tire tread with a tear-drop shaped base, providing enhanced engagement with icy surfaces and improved retention within the tread rubber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional stud pins are embedded in the tread portion, then the tire can grip icy or snowy road surfaces, but the stud pins are dislodged on concrete or asphalt surfaces due to driving, braking, and cornering forces

Engineering Contradiction:
Improvestud pin retentionVSAvoidresistance to dislodging forces
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The stud pin features an asymmetric geometry with a larger diameter base portion embedded in the tread and a smaller diameter shank portion extending outward. This asymmetric design creates a mechanical interlock where the larger base provides anchorage in the rubber while the smaller shank presents a reduced profile to road surfaces, preventing rotational dislodging during driving, braking, and cornering operations.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The stud pin transitions from a simple cylindrical shape to a multi-dimensional structure with varying cross-sectional areas along its length. The base portion has a larger cross-section for embedding, the shank portion has a smaller cross-section for reduced road surface contact, and the tip features a specific geometry for ice penetration. This dimensional variation optimizes both retention and performance.

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

2Reliability

If the stud pin is tightly embedded in the tread rubber, then the stud pin does not fall out during normal operation, but the clawing force on concrete or asphalt surfaces overcomes the retaining force and causes pin drop

Engineering Contradiction:
Improvestud pin retentionVSAvoidclawing force from road surface
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The asymmetric cross-sectional geometry creates a mechanical interlock effect where the stud pin is easily inserted into the tread rubber but difficult to extract. The larger base portion creates significant friction and mechanical resistance to pull-out forces, while the smaller shank portion minimizes the lever arm for rotational clawing forces during driving operations.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The stud pin is pre-formed with an optimized geometry during manufacturing, including the tapered shank and flanged base, so that it achieves optimal retention characteristics upon installation without requiring additional field modifications or adjustments.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If the stud pin has a simple cylindrical shape, then the manufacturing process is simple, but the stud pin lacks optimized engagement with icy surfaces and reduced pin drop resistance

Engineering Contradiction:
Improvestud pin fabricationVSAvoidtraction and durability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The stud pin is divided into distinct functional segments: a base portion for embedding in the tread, a shank portion for structural support and reduced road contact, and a tip portion for ice engagement. Each segment can be optimized independently for its specific function while being manufactured as an integrated component through processes like extrusion or forging.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stud pin geometry incorporates specific parameter variations including diameter changes along the length, angular orientations of the shank relative to the base, and tip geometry optimizations. These parameter changes are achieved through controlled manufacturing processes that can produce complex three-dimensional shapes from material blanks.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3643528B1Tire stud and studded tire
Publication Date: 2021.06.23 THE GOODYEAR TIRE & RUBBER CO
  • EP3643528B1 patent drawingFigure 1~2
  • EP3643528B1 patent drawingFigure 3~4
  • EP3643528B1 patent drawingFigure 5

AI summary

A stud (50) configured to be inserted into a tread (18) of a tire is disclosed. The stud (50) comprises a tip end (52) configured for protruding from the tread portion (18) for contacting a road surface; and a base (54) including a flanged bottom portion (58) provided on an end of the stud (50) opposite the tip end (52) and, when the stud (50) is inserted in the tread (18), extending radially outwards, a stump portion (56) provided between the bottom portion (58) and the tip end (52), and a shank portion (60) interconnecting the stump portion (56) and the bottom portion (58) of the base (54). The base (54) is configured for being embedded and secured in the tread (18) of the tire in which the stud (50) is configured to be installed. The circumferential line or cross-section of the flanged bottom portion (58), when viewed in top view onto the stud (50) along an axis from the tip end (52) to the flanged bottom portion (58), consists of or comprises one semi-cylindrical (117) or semi-ellipsoidal side and either three planar sides (111, 113, 115), one planar side and two concave sides, or two planar sides and one semi-cylindrical, semi-ellipsoidal or concave side.