Purlin Aperture Design for Roofing Assembly Versatility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The complexity in assembling roofing structures due to varying attachment requirements and orientations, which often necessitates different purlins or different assembly configurations, complicates the construction process and can be hindered by cleat reinforcements.
Innovation Solution
A purlin design featuring a longitudinal axis with opposing flanges and a web having strategically positioned apertures of different sizes, allowing for easy assembly by preventing fastener interference and enabling secure attachment using a consistent fastener size, with apertures arranged in a trapezoidal or rectangular pattern for efficient mating and connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different purlins are provided to allow for different fixing in place, then the adaptability of the roofing structure is improved, but the device complexity and quantity of parts increase
Solution Approach 1:
The purlin is designed with multiple apertures of different sizes (first aperture larger than second aperture) that can accommodate different fastening configurations. The same purlin component can be fixed in multiple orientations and positions by selecting different apertures for fastener insertion, eliminating the need for multiple specialized purlin types while maintaining versatility in attachment options.
2Strength
If a cleat has a central gusset for reinforcement, then the strength of the cleat is improved, but the ease of assembly deteriorates due to interference with purlin mating
Solution Approach 1:
The purlin features asymmetric aperture sizing where the first aperture is deliberately made larger than the second aperture. This asymmetry allows the larger first aperture to serve as a clearance hole that accommodates fasteners and their heads/nuts, preventing interference with the mating purlin while the smaller second aperture provides precise positioning. This resolves the conflict between structural reinforcement needs and assembly ease by creating selective aperture functions.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A purlin comprising an elongate member which forms a profile having two opposing sides and an intermediate body portion. The intermediate body portion has formed therein a series of apertures for attaching the purlin to another purlin or to a cleat for securing the purlin to a roofing structure. The series of apertures formed therein include four apertures arranged in a rectangular pattern and with one of the apertures being in the form of a slot. Three apertures are dimensioned to be smaller than both the head of a bolt and the nut of a bolt, both of a given size, so that the purlin can be secured to another purlin or to a cleat by passing said bolt through a respective one of the apertures and securing said nut in place. The aperture in the form of a slot is dimensioned to be larger than both the head of said bolt and the nut of said bolt so that both the head and the nut of said bolt of a given size passes through the slot. A roofing structure comprising at least two such purlins is also disclosed. A method of forming a roofing structure comprises the steps of: (a) providing a cleat; (b) providing a first purlin of the invention; (c) securing the first purlin to the cleat using a by a nut and bolt; (d) providing a second purlin of the invention; (e) overlapping the second purlin and the first purlin so that the nut and/or bolt passes through the aperture in the form of a slot defined in the second purlin.