Bolt Extender Assembly for Full Thread Engagement
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Solution Overview
Problem
The existing bolted foundation system is compromised when threaded rods do not project far enough out of the concrete foundation, preventing full engagement of nuts and thus reducing the structural strength of the connection between the pole and the foundation.
Innovation Solution
A bolt extender arrangement featuring a longitudinal fitting with a hollow, internally-threaded end and a solid, externally-threaded end, along with a shoulder, is used to extend the threaded rods, ensuring full thread engagement by the nuts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If threaded rods are embedded deeply in the concrete foundation to achieve full nut engagement, then the connection strength is improved, but the installation complexity and difficulty increase
Solution Approach 1:
The bolted connection system is segmented into modular components: the embedded threaded rod, the bolt extender with internal threads, and the nut. This segmentation allows the rod to be embedded at any depth while the extender provides the additional threading length needed for full nut engagement, thereby maintaining connection strength without requiring excessively deep embeddings
Solution Approach 2:
The bolt extender acts as an intermediary component between the embedded threaded rod and the nut. It bridges the gap when the rod projection is insufficient, providing the additional threaded surface area needed for full nut engagement. This intermediary element resolves the contradiction by decoupling the embedding depth requirement from the engagement length requirement
2Reliability
If threaded rods project longer out of the foundation, then full nut engagement is achieved, but the rod stability and anchoring strength decrease
Solution Approach 1:
The system separates the anchoring function (performed by the embedded portion of the rod in the concrete) from the engagement function (performed by the extender and nut assembly). This allows optimal embedding depth for anchoring strength while adding external threading length for reliable nut engagement without compromising either function
Solution Approach 2:
The bolt extender serves as a mediator that extends the threaded surface outward from the foundation without requiring the rod itself to project longer. This maintains the rod's embedded depth and anchoring strength while providing sufficient projection length for full nut engagement through the extender's internal threads
3Reliability
If the threaded rod projection length is increased, then full thread engagement is possible, but the manufacturing precision requirements increase
Solution Approach 1:
The system changes the parameter of where the threading length is provided. Instead of requiring the rod to have both optimal embedding depth and sufficient projection length (two conflicting constraints), the threading function is moved to the extender component. This allows the rod to be manufactured with precise embedding depth only, while the extender provides the additional threading length with its own manufacturing tolerances
Solution Approach 2:
The bolt extender mediates the precision requirements by being the component that accommodates variations in rod projection length. It provides a standardized internal threading interface that ensures full nut engagement regardless of slight variations in rod installation depth, thereby reducing the stringency of rod projection precision requirements
Data Source
AI summary
A bolt extender includes a bottom portion defining internal threads and a multi-sided outer surface, an upper shoulder, and a threaded rod projecting upwardly from said upper shoulder.