Panel Fastening Washer with Sheath for Coating Protection

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Solution Overview

Problem

Existing fixation methods for coated panels on wooden or metal supports damage the panel surface due to dimensional changes, causing abrasion and water penetration, and fail to address aesthetic and durability concerns.

Innovation Solution

A panel fastening assembly with a washer inserted between the in-driving means and the panel, featuring a cylindrical sheath with an inner diameter larger than the shank and an outer diameter smaller than the in-driving means' head, allowing panel movement without surface damage, and designed to be discreet and weather-resistant.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If screws or rivets are tightly fixed to the panel surface, then the panels are securely fixed to avoid vibration and noise, but the coatings are scratched and damaged during dimensional changes

Engineering Contradiction:
Improvefixation strengthVSAvoidcoating abrasion
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

A washer with a sheath is introduced as an intermediary element between the screw/rivet head and the panel surface. The sheath fits into a countersunk hole in the panel, while the washer head bears the fixation load. This mediator allows the fastener to remain securely fixed while preventing direct contact between the hard screw/rivet head and the soft coating, thus avoiding abrasion during panel dimensional changes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the geometric parameters of the fixation system by using a washer with specific dimensions: the sheath outer diameter matches the countersunk hole diameter, the sheath inner diameter is larger than the screw/rivet shank diameter, and the washer head diameter is larger than the sheath outer diameter. These parameter changes create a system where the fastener is securely anchored while the coating is protected from direct contact and abrasion.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If holes are drilled larger than the shank diameter to allow panel movement, then dimensional changes are accommodated, but the fixation strength is reduced and vibration noise increases

Engineering Contradiction:
Improvedimensional change accommodationVSAvoidfixation strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The washer with sheath acts as an intermediary that bridges the gap between the screw/rivet shank and the enlarged hole. The sheath fits into a precisely sized countersunk hole, providing a stable anchor point, while the washer head accommodates panel movement. This mediator allows the fastener to maintain strong fixation while accommodating dimensional changes without direct contact between the shank and the enlarged hole walls.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention transitions from a one-dimensional fit (shank in hole) to a two-dimensional solution by introducing the washer head that sits on the panel surface. The sheath provides anchorage in the vertical dimension, while the washer head provides a bearing surface in the horizontal dimension, allowing panel movement without compromising fixation strength.

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

3Object-affected harmful factors

If a thin metal tube is inserted into the fixation hole to reduce pressure on the coating, then coating damage is reduced, but additional operations are required to avoid vibration noise

Engineering Contradiction:
Improvecoating damageVSAvoidinstallation complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention merges the protective function (reducing pressure on coating) and the vibration-damping function into a single integrated component: the washer with sheath. The sheath protects the coating by fitting into the countersunk hole, while the washer head provides a bearing surface that prevents vibration noise. This consolidation eliminates the need for separate rubber foam ribbons and additional installation steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts the vibration-damping function from separate rubber foam elements and integrates it into the metal washer structure itself. The washer head's geometry and material properties provide inherent vibration damping capabilities, eliminating the need for additional vibration-damping components and simplifying the overall system.

Inventive Principle:
Principle #2Taking out (Extraction)

4Strength

If the washer outer diameter equals the hole diameter to fit tightly, then the washer provides good support, but it becomes visible and unsightly during thermal or hydric movement

Engineering Contradiction:
Improvesupport capabilityVSAvoidaesthetic appearance
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The invention uses asymmetric dimensions for the washer components: the sheath outer diameter matches the countersunk hole diameter for a tight fit and good support, while the washer head diameter is deliberately made larger than the sheath outer diameter. This asymmetry ensures that even when the panel moves thermally or hydropically, the larger washer head remains visible and provides aesthetic coverage, while the sheath maintains its supportive function.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The washer head diameter is made excessively large compared to the minimum required for structural support. This excessive dimension ensures that the washer remains visually concealed during panel movement, prioritizing aesthetic appearance while the sheath provides the necessary structural support capability.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2096231B1Fixation device for panels
Publication Date: 2010.07.07 REDCO
  • EP2096231B1 patent drawingFigure 1~2

AI summary

A panel fastening assembly (8) for fastening panels (2) provided with through-holes (4) to a support (6). This assembly comprises in-driving means (10) which comprises a head (12) placed towards a proximal side of its axis, and a shank (14) whose length is longer than the thickness of the panel (2). A washer (18) is inserted between the in-driving means (10) and the panel (2), and has an inner diameter substantially equal to the diameter of the through-hole (4) and an outer diameter which is smaller than the diameter of the in-driving means head (12). The inner side of the washer (18) extends to form a sheath (16) having an outer diameter substantially equal to the diameter of the through-hole (4), an inner diameter which is larger than the shank's (14) diameter and an axial length which is not longer than the thickness of the panel (2) to be fixed. The diameter of the head (12) of the in-driving means (10) is at least equal to the sum of the outer diameter of the washer (18) and of the difference between the outer radius of the shank (14) and the inner radius of the sheath (16).