Segmented Thermal Insulation Anchor with Variable Thread Geometry
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Solution Overview
Problem
Existing anchors for thermal insulation layers on buildings face challenges in securing a hold in elastic insulating materials while also being able to pass through holes in components without pre-drilling, often resulting in thermal bridges due to the fastening screw extending into the masonry.
Innovation Solution
The anchor features a shank with a drill bit and a thread that has varying flank heights and diameters, allowing for a secure hold in elastic materials and enabling the anchor to be screwed through holes without pre-drilling, using a design with a first cylindrical section for maximum thread flank height and a second section with a larger diameter and reduced flank height to accommodate larger shank diameters, and optionally including a truncated cone-shaped section for centering and a radially extending collar for prevention of rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the thread flank height is increased to ensure secure hold in elastic insulating materials, then the anchoring strength is improved, but the anchor cannot be screwed through holes in components without pre-drilling
Solution Approach 1:
The anchor shaft is divided into two distinct sections: a first section with a first diameter and large thread flank height for anchoring in insulation material, and a second section with a second larger diameter and reduced thread flank height for passing through component holes. This segmentation allows each section to be optimized for its specific function without compromise.
Solution Approach 2:
Different portions of the anchor shaft are given different geometric properties: the first section has larger thread flank height for maximum grip in elastic insulation material, while the second section has reduced thread flank height and larger diameter to fit through pre-drilled or self-drilled holes in components. Each local region is tailored to its functional requirement.
2Strength
If the shaft diameter is increased to accommodate larger components, then the load-bearing capacity is improved, but the anchor cannot pass through holes in components
Solution Approach 1:
The shaft is segmented into a first section with smaller diameter for passing through component holes and a second section with larger diameter for enhanced load-bearing capacity and component accommodation. The transition between sections is achieved through a frustoconical intermediate section.
Solution Approach 2:
The anchor design utilizes the longitudinal dimension of the shaft to resolve the diameter conflict. By varying the diameter along the length of the shaft (creating sections with different diameters), the anchor achieves both small enough diameter to pass through holes and large enough overall diameter for load-bearing capacity.
3Ease of operation
If the anchor is designed to penetrate insulation and plaster layers without pre-drilling, then the installation process is simplified, but the anchor may turn during screwing
Solution Approach 1:
A collar is added to the anchor that extends radially outward from the shaft. This asymmetric feature creates resistance to rotational movement during installation, preventing the anchor from turning while being screwed into the insulation material without pre-drilling.
Solution Approach 2:
The collar acts as an intermediary element between the anchor shaft and the surrounding insulation material. It provides the necessary friction and mechanical interference to prevent rotation, while not interfering with the primary anchoring function of the threaded shaft.
Data Source
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AI summary
The invention relates to a dowel for arrangement in thermal insulation layers, in particular on buildings, comprising a shaft, a drill tip at a first end of the shaft, a second end of the shaft opposite the first end, and at least one thread on the shaft, wherein the shaft has a first cylindrical section adjoining the drill tip with a first diameter and a second cylindrical section with a second, larger diameter, wherein the second section is arranged between the first section and the second end, wherein the first section and the second section are provided with the thread, and wherein a maximum value of the thread flank height in the first section is greater than in the second section.