Angled Dowel Joints for Multi-Layer Timber Wall Stability
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Solution Overview
Problem
Current dowel-based connection methods in wood panel construction, where dowels are pressed perpendicular to the wall, fail to ensure cohesion between board layers under large tensile forces or construction loads, leading to instability in multi-layer solid wood structures.
Innovation Solution
Arranging dowels at angles to each other and pressing them in two or more dimensions creates a secure connection between board layers, using dowel knots that allow for expansion and contraction without compromising stability, and enabling the incorporation of insulation mats between layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dowels are pressed perpendicular to the wall over several layers, then the connection process is simple, but the cohesion between board layers cannot be guaranteed under large tensile forces or construction loads
Solution Approach 1:
The patent transitions from one-dimensional perpendicular dowel arrangement to two-dimensional oblique dowel arrangement. The dowels are inclined at angles between 45-60 degrees relative to the wall surface, creating a multi-directional connection system that resists tensile forces more effectively while maintaining manufacturing feasibility.
Solution Approach 2:
The patent employs asymmetric dowel arrangement where dowels are positioned at specific oblique angles rather than symmetrically perpendicular to the wall. This asymmetric configuration optimizes the mechanical interlocking between layers, preventing detachment under load while preserving ease of installation.
2Reliability
If dowels are arranged at an angle and pressed in two or more dimensions, then the board layers are inextricably connected, but the device complexity increases
Solution Approach 1:
The patent divides the connection system into discrete oblique dowel units arranged in a systematic pattern. Each dowel acts as an independent connection element at a specific angle, allowing the complex multi-dimensional connection to be achieved through repetition of standardized components rather than a monolithic complex structure.
Solution Approach 2:
The patent specifies precise angular parameters (45-60 degrees) for dowel arrangement to optimize connection stability. By controlling these geometric parameters, the system achieves high reliability through standardized angular configurations rather than arbitrary complex arrangements.
3Reliability
If dowel knots are used in the middle area of the board, then wood shrinkage and swelling is diverted to expansion joints, but the distances between board layers must be precisely fixed
Solution Approach 1:
The patent incorporates insulation mats between board layers during the assembly process, before the structure is subjected to environmental changes. This preliminary placement ensures proper spacing and accommodates future wood shrinkage and swelling movements, preventing distortion of the overall structure.
Solution Approach 2:
The patent uses insulation mats as intermediary elements between board layers. These mats serve multiple functions: maintaining precise spacing, accommodating wood dimensional changes, and providing thermal insulation. The mats act as a buffer that absorbs movement without compromising structural integrity.
Data Source
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AI summary
Dowel joints consisting of two or more dowels arranged at an angle to each other, suitable for the production of wall and ceiling elements for timber constructions. With current technology, dowels are pressed in vertically to the wall through several layers. The disadvantage of this technique is that under high tensile forces (warping of several boards) or high structural loads on the building, the cohesion between the board layers cannot be guaranteed. According to the invention, the dowels are arranged at an angle to each other and pressed in two or more dimensions, so that the individual board layers are permanently bonded together. Multi-layered solid wood walls and ceilings can be produced using these angled dowels (dowel joints). Insulation mats can also be incorporated between the board layers.