Tie Rod Fastener Spring Tensioning System
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Solution Overview
Problem
Existing reinforced building wall systems face challenges in effectively resisting uplift forces, particularly during earthquakes and high winds, as current fasteners and springs fail to provide adequate tension and load sharing, leading to potential bowing or buckling of tie rods.
Innovation Solution
A system comprising a pre-compressed spring that provides tension to a tie rod, combined with a hold down fastener that travels down the rod, where the spring is independent of the fastener and can actuate it to resist uplift forces, and a dual-fastener system that shares load, with one fastener being made of plastic for color-coded size compatibility and force actuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single fastener is used to resist uplift forces, then the device complexity is reduced, but the reliability is insufficient due to lack of load sharing
Solution Approach 1:
The fastener system is divided into multiple independent fasteners (first fastener and second fastener) that can slide independently on the rod. Each fastener has its own bearing plate and engagement mechanism, allowing them to share uplift loads separately rather than relying on a single fastener, thus improving reliability while maintaining relatively simple device complexity.
2Force
If the spring is made larger in diameter to provide sufficient tension, then the force is improved, but the ease of operation deteriorates due to difficulty in installation
Solution Approach 1:
The spring is designed with a diameter larger than the rod to provide sufficient tension force, yet it can be installed by nesting the spring around the rod and using the rod itself as a guide for installation. The spring's outer diameter is controlled to be larger than the rod diameter but smaller than the fastener housing diameter, allowing it to be positioned during assembly without requiring separate installation tools or complex procedures.
3Ease of operation
If the spring diameter is made smaller than the rod, then the ease of operation is improved, but the force is insufficient to provide adequate tension
Solution Approach 1:
The spring is designed with a specific diameter range that is larger than the rod diameter (to provide sufficient tension force) but smaller than the fastener housing diameter (to allow easy installation). This local quality control of the spring's dimensional parameters allows it to simultaneously achieve both sufficient force generation and ease of installation during the assembly process.
4Ease of operation
If the fastener is made of plastic for color coding, then the ease of operation is improved, but the strength is reduced compared to metal fasteners
Solution Approach 1:
The plastic fastener housing is color-coded (e.g., green for 1/2 inch rod, yellow for 5/8 inch rod, red for 3/4 inch rod) to provide immediate visual identification of the correct fastener size for different rod diameters. This color coding system improves ease of operation during installation by eliminating confusion about fastener sizing, while the plastic material maintains sufficient strength through proper structural design and material selection.
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, prevents bowing or buckling of tie rods, and accommodates wall settlement or shrinkage by providing sufficient tension and load sharing, ensuring the structural integrity of building walls.
Implementation Method 1
a spring for providing tension to a rod
Implementation Method 2
the spring providing sufficient force equal to about one half of the weight of the rod below
Implementation Method 3
flexible fingers that bear on the flanks of the threads of the rod when an upward force is exerted on the body
Implementation Method 4
the spring is pre-compressed prior to installation
Data Source
AI summary
A building wall includes a stud wall with a horizontal wall member; a tie rod operably anchored in a foundation, the tie rod extending through the wall member; a first fastener and a second fastener attached to the tie rod, the first fastener and the second fastener being slidable down the tie rod, first fastener being operably disposed on the wall member and lockable to the tie rod in an upward direction to resist uplift forces from the stud wall, and the second fastener being disposed above the first fastener resist the spring; and a spring operably operating on the first fastener and the second fastener to urge the first fastener downwardly toward the wall member, the second fastener being disposed above the first fastener and lockable to the tie rod in the upward direction to restrain the spring.