Locking Washer Segmented Ring Angles Prevent Loosening

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Solution Overview

Problem

Existing locking washers face challenges in maintaining preload force due to setting and creep processes, leading to loosening in screw connections, and previous disc constructions either lack sufficient spring force or are prone to 'gaping' under high tightening forces.

Innovation Solution

A locking washer design with a circumferential groove on the underside and a steeper angle between the outer ring section surface and the base, combined with profiling on the upper side, enhances the spring properties and securing effect, allowing for a smaller outer diameter with improved locking performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a step is introduced on the underside to divide the outer ring section surface and inner ring section surface, then initial spring force is generated with specific spring deflection, but the outer edge of the outer ring section surface may lift off the base during further tightening

Engineering Contradiction:
Improvespring forceVSAvoidcontact stability
Core Design Contradiction:
ForceVSStability of the object's composition

Solution Approach 1:

The washer is divided into two functional zones: an outer ring section with a steeper angle (10°-20°) that generates initial spring force, and an inner ring section with a smaller angle (3°-15°) that maintains stable contact. This segmentation allows each zone to perform its specific function without interfering with the other, preventing the outer edge from lifting off while maintaining sufficient spring force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different angular characteristics are applied to different regions of the washer. The outer ring section has a steeper angle to provide initial spring force, while the inner ring section has a shallower angle to ensure stable contact and prevent lifting. This local differentiation of geometric properties optimizes both spring force generation and contact stability.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If the surface of the outer ring section merges continuously into the inner ring section without a step, then gaping is reduced, but sufficient spring force with small deflection cannot be achieved

Engineering Contradiction:
Improvecontact continuityVSAvoidspring force
Core Design Contradiction:
Stability of the object's compositionVSForce

Solution Approach 1:

The continuous surface is segmented into two distinct angular zones separated by a circumferential groove. The outer zone has a steeper angle for spring force generation, while the inner zone has a shallower angle for stable contact. The groove prevents the harmful leverage effect while preserving the beneficial angular characteristics of both zones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution moves from a two-dimensional continuous surface to a three-dimensional structure with a circumferential groove creating distinct zones. This dimensional change allows the groove to act as a barrier that prevents the outer edge from lifting while maintaining the angular characteristics needed for spring force generation.

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

3Reliability

If the outer ring section area is made relatively large to reduce gaping, then locking effect is improved with large outer diameters, but material usage and device complexity increase

Engineering Contradiction:
Improvelocking effectVSAvoidwasher geometry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The washer geometry is optimized by applying different angular characteristics to different regions. The outer ring section has a steeper angle optimized for spring force generation, while the inner ring section has a shallower angle for stable contact. This local optimization achieves reliable locking without requiring excessive outer diameter or complex geometry.

Inventive Principle:
Principle #3Local quality

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

The design achieves a stronger vertical force component during tightening, ensuring better contact and securing the outer edge into the base, thereby maintaining clamping force and preventing loosening, even under high tightening forces.

Implementation Method 1

the spring properties of the disk are improved

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the contact force acts at a steeper angle to the flat surface, ie the force component in the vertical direction is higher than the force component in the horizontal direction

Methodology Applied
Scientific EffectForce component resolution: Force

Data Source

PatentEP2287477B1Locking washer
Publication Date: 2016.02.10 TECKENTRUP GMBH & CO KG
  • EP2287477B1 patent drawingFigure 1~3

AI summary

The locking washer has outer and inner ring surfaces (2, 3) arranged at an angle with respect to each other at a lower side of a ring-shaped disk body, where the lower side is turned towards a contact surface. An outer edge (4) of the outer ring surface lies on a base (5) in an unclamped state of a disk. An angle formed between the outer ring surface and the base is greater than angle formed between the inner ring surface and the base. A circulating channel is formed at an upper side of the washer, and runs parallel to a channel (8) formed at a lower side of the washer.