Metal Web Engagement Formations for Timber Truss Stability

Solution Overview

Problem

Existing metal webs in trusses are prone to detachment from timber chords and buckling during the manufacturing process due to movement during embedding and lack of support, which affects the structural integrity and stability of the trusses.

Innovation Solution

Incorporating engagement formations on the metal webs that embed into the timber elements transversely, providing additional support to the spacing portions and preventing displacement during pressing, thereby enhancing attachment security and reducing buckling likelihood.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal webs are pressed into timber chords during manufacturing, then attachment security is improved, but the metal webs may move slightly during the pressing process causing positioning errors

Engineering Contradiction:

Improveattachment securityVSAvoidpositioning accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by providing engagement formations (locating lugs or engagement tabs) that embed into the timber element before the pressing operation. These formations are positioned to engage the timber surface in advance, preventing movement of the metal web during the subsequent pressing process. The locating lugs extend beyond the plane of the attachment portion and embed into the timber element to a specified depth, securing the metal web in its correct position before the attachment portions are pressed into the chords.

Inventive Principle:

Principle #10Preliminary action

2Loss of substance

If spacing portions of metal webs are made slender to reduce weight, then material usage is improved, but buckling resistance deteriorates

Engineering Contradiction:

Improvematerial usageVSAvoidbuckling resistance

Core Design Contradiction:

Loss of substanceVSStrength

Solution Approach 1:

The patent applies preliminary action by providing engagement formations (locating lugs or engagement tabs) that embed into the timber element before the pressing operation. These formations are positioned to engage the timber surface in advance, preventing movement of the metal web during the subsequent pressing process. The locating lugs extend beyond the plane of the attachment portion and embed into the timber element to a specified depth, securing the metal web in its correct position before the attachment portions are pressed into the chords.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies dimensionality change by adding engagement formations that extend in a direction perpendicular to the plane of the attachment portion. The locating lugs extend beyond the plane of the attachment portion and embed into the timber element, providing support in a new dimensional direction. This additional dimensional support prevents buckling of the spacing portions without requiring increased thickness or material usage in the original plane.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Strength

If engagement formations are added to metal webs, then buckling resistance is improved, but device complexity increases

Engineering Contradiction:

Improvebuckling resistanceVSAvoidweb structure complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by designing the engagement formations (locating lugs or engagement tabs) to serve multiple functions simultaneously. The locating lugs not only prevent buckling of the spacing portions but also provide positioning accuracy during manufacturing and enhance the overall structural integrity. By combining multiple functions into a single feature, the patent avoids increasing device complexity while achieving improved performance.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution significantly improves the resistance to buckling of the metal web spacing portions and secures the attachment portions more effectively to the timber chords, enhancing the structural stability and load-bearing capacity of the trusses by approximately 5% before buckling occurs.

Implementation Method 1

the metal web is resistant to displacement while the teeth on the attachment portions are being pressed into the timber elements

Methodology Applied

Scientific EffectEmbedding: Mechanical Fastener

Implementation Method 2

the spacing portions between the attachment portions are provided with flanges along their edges to resist bending and buckling under the loads imposed thereon

Methodology Applied

Scientific EffectBuckling resistance: Mechanical Force

Data Source

PatentEP1985774B2Metal webs in and for timber trusses

Publication Date: 2014.07.30 WOLF SYSTEMS LIMITED

Figure 1
Figure 2
Figure 3

AI summary

A metal web (32, 34) for connecting timber elements (12, 14) in spaced relation to one another in a truss, the metal web comprising respective attachment portions (36, 38, 40) having attachment formations able to be embedded into attachment faces (22, 34) of the timber elements which face the respective attachment portions, and at least one spacing portion (42, 44) extending between the attachment portions, wherein the web is provided with at least one engagement formation (62, 66) adapted to become embedded in a surface of a respective timber element extending transversely of an adjacent attachment face of the timber element.