Wood Connector Finger Joint Profile for Strength
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Solution Overview
Problem
Existing wood connectors in timber engineering lack sufficient load-bearing strength, especially when used with fast-growing woods of lower bulk density, requiring increased screw numbers to compensate, which complicates production and increases weight and costs.
Innovation Solution
Incorporating a finger joint profile on at least one side of the fittings, which creates a high-strength, form-fitting connection with the workpiece, allowing for reduced screw requirements and improved force absorption, and optionally gluing for additional bonding, while using an adapter plate for modular construction with different finger joint profiles to adapt to various wood qualities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If screw connections are increased in number to compensate for lower bulk density in fast-growing woods, then load-bearing strength is improved, but device complexity and manufacturing costs increase
Solution Approach 1:
The fitting is divided into a base body and a separate adapter plate with the finger joint profile. This segmentation allows the finger joint mechanism to provide the primary load-bearing function, reducing the number of screws needed compared to conventional solid fittings in low-density wood.
Solution Approach 2:
The connector system combines metal fittings with wood finger joints to create a composite connection. The finger joint profile creates interlocking wooden teeth that provide mechanical strength, while the metal fittings provide structural support, achieving high load-bearing capacity with fewer fasteners.
2Strength
If finger joint profile is added to fittings, then load-bearing strength and moisture seal are improved, but device complexity increases
Solution Approach 1:
The finger joint profile is segmented into a separate adapter plate that attaches to the fitting base body. This allows the complex finger joint geometry to be manufactured independently and then assembled, reducing the overall manufacturing complexity while maintaining the strength and sealing benefits.
Solution Approach 2:
The adapter plate serves as an intermediary component between the simple metal fitting base body and the complex finger joint profile. It transfers loads and provides the finger joint functionality without requiring the entire fitting to be complex, thus reducing overall device complexity.
3Adaptability or versatility
If adapter plates with different finger joint profiles are used to adapt to different wood qualities, then adaptability is improved, but device complexity and inventory requirements increase
Solution Approach 1:
The fitting base body is designed as a universal component that can work with any adapter plate. The standardized interface allows a single base body design to support multiple adapter plate variants with different finger joint profiles, reducing the need for completely different fitting designs for different wood types.
Solution Approach 2:
The system allows dynamic adaptation by selecting different adapter plates based on the specific wood quality being connected. This modular approach enables the connector system to adapt to varying conditions without requiring a complete redesign, balancing versatility with manageable complexity.
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
Enhances load-bearing strength, reduces moisture penetration, minimizes screw requirements, and simplifies production by creating a self-locking force absorption mechanism, suitable for diverse wood types and materials, while maintaining ease of assembly and disassembly.
Implementation Method 1
the flank angles of the finger teeth of the finger joint profile are preferably designed to be self-locking in order to ensure good absorption of force
Implementation Method 2
a high-strength finger joint can be created between fitting and workpiece, which achieves an intimate, form-fitting and force-fitting connection
Implementation Method 3
a good seal of the end grain surface of the beam can be achieved at the same time, reducing the risk of moisture penetrating the wood or the glue
Implementation Method 4
by at least a threaded rod can be clamped against each other, which runs approximately parallel to the other sides mentioned
Implementation Method 5
the clamping jaws press the two fittings firmly against one another via their keyways
Implementation Method 6
the named ends of the fittings are wedge-shaped and each clamping jaw has a keyway to accommodate two adjacent wedge-shaped ends
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a connector (1) for two workpieces (2, 3), with two fittings (4, 5) which can be attached to one of the workpieces (2, 3) with one side (6, 7) and brought into contact with each other with their other side (8, 9), and two clamping jaws (10, 11) which grip the fittings (4, 5) at diametrically opposed ends (14, 15; 16, 17) and can be clamped against each other by means of at least one threaded rod (18) which runs approximately parallel to the aforementioned other sides (8, 9), wherein the aforementioned one side (6, 7) of at least one fitting (4, 5) is provided with a finger-joint profile (26, 27).