Hydraulic Expandable Connector for Wood Shrinkage Slack Compensation
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Solution Overview
Problem
Existing hold-down systems in light frame construction fail to effectively resist uplift and compensate for wood shrinkage and compression loading, leading to potential structural instability during natural disasters or settlement.
Innovation Solution
A hydraulic expandable connector system comprising an inner and outer cylindrical body with a spring mechanism and fluid chambers, allowing for axial expansion to take up slack in tie rods, and a valve system to manage fluid flow and pressure for load resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional rigid hold-down system is used, then the structure provides initial stability, but it cannot compensate for wood shrinkage and cannot effectively resist uplift forces
Solution Approach 1:
The hold-down system transitions from a rigid static structure to a dynamic system with expandable connector that can adapt its length. The connector includes an inner cylindrical body that can move axially relative to an outer cylindrical body, allowing the system to compensate for wood shrinkage and settlement while maintaining structural integrity and uplift resistance.
Solution Approach 2:
The system uses a hydraulic mechanism with fluid-filled chambers to enable controlled expansion of the connector. Fluid pressure acts on a piston to push the inner cylindrical body outward, allowing the connector to expand and take up slack in the tie rod, thereby compensating for wood shrinkage while maintaining load-bearing capacity.
2Adaptability or versatility
If the connector expands to take up slack in the tie rod, then it compensates for wood shrinkage, but the valve system complexity increases
Solution Approach 1:
The valve system operates automatically based on pressure differential without requiring external control. The valve opens when fluid pressure exceeds a threshold during expansion, and closes when pressure equalizes, enabling self-regulated slack compensation while maintaining structural stability under load.
3Force
If the valve is in the closed position to resist axial load, then uplift resistance is provided, but fluid flow is restricted
Solution Approach 1:
The valve system provides pressure feedback control where the closed position maintains high fluid pressure to resist uplift forces, while the open position allows pressure equalization during expansion. The system automatically transitions between states based on the structural needs, balancing force resistance with fluid flow requirements.
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 system effectively resists uplift forces and compensates for wood shrinkage and compression loading, providing enhanced structural stability by expanding to absorb slack and pressurizing fluid for load resistance.
Implementation Method 1
a first actuation spring operably attached to the inner cylindrical body and the outer cylindrical body to urge relative motion between the inner cylindrical body and the outer cylindrical body such that the connector expands axially
Implementation Method 2
a first chamber and a second chamber disposed between an outer wall surface of the inner cylindrical body and an inner wall surface of the outer cylindrical body; a first passageway communicating between the first chamber and the second chamber
Data Source
AI summary
A hydraulic expandable connector for taking up a slack in a tie rod in a hold-down system includes an inner cylindrical body disposed within an outer cylindrical body; a first actuation spring operably attached to the inner cylindrical body and the outer cylindrical body to urge relative motion between the inner cylindrical body and the outer cylindrical body such that the connector expands axially to take up the slack; a first chamber and a second chamber disposed between an outer wall surface of the inner cylindrical body and an inner wall surface of the outer cylindrical body; a first passageway communicating between the first chamber and the second chamber; and a valve operably disposed in the first passageway in an open position when the connector expands and a closed position when the connector is subjected to an axial load.