Lockwireless Rod Assembly With Ratcheting Nut Lock
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Solution Overview
Problem
Rod assemblies in applications like aircraft face issues with nut loosening due to vibration or forces, requiring lockwires that increase complexity and manufacturing costs.
Innovation Solution
A connector assembly featuring a threaded shaft, nut with radially outward protrusions, and a tab made of resilient material that engages with serrations to inhibit nut rotation, allowing ratcheting during tightening while preventing loosening, eliminating the need for lockwires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lockwire is inserted through the nut to prevent loosening, then the nut's rotational stability is improved, but the device complexity and manufacturing time increase
Solution Approach 1:
The invention extracts and eliminates the lockwire component from the rod assembly by integrating the locking function directly into the nut structure through serrations and tab engagement, thereby reducing device complexity while maintaining rotational stability
Solution Approach 2:
The locking function previously performed by a separate lockwire is merged into the nut itself through the integration of serrations and tab engagement features, simplifying the overall assembly by combining multiple functions into a single component
2Reliability
If a lockwire is used to secure the nut, then the nut's resistance to loosening is improved, but the manufacturing cost increases
Solution Approach 1:
The invention removes the lockwire component and its associated manufacturing steps, reducing material costs and assembly operations while maintaining anti-loosening capability through the serration-tab mechanism
Solution Approach 2:
The nut structure provides its own locking function through integrated serrations and tab engagement, eliminating the need for separate locking components and reducing manufacturing complexity and cost
3Ease of operation
If the nut is allowed to rotate freely for tightening, then the ease of operation is improved, but the ability to maintain position after tightening is worsened
Solution Approach 1:
The invention creates a dynamic system where the tab can move radially during tightening operations to accommodate nut rotation, then engages with the serrations to lock the position, providing both ease of operation and position maintenance
Solution Approach 2:
The locking mechanism is segmented into distinct functional elements: the serrations on the nut, the tab with ramp surfaces, and the engagement geometry, allowing independent optimization of tightening operation and position locking functions
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 solution securely locks the nut in place without the need for lockwires, reducing manufacturing complexity and costs while maintaining the rod assembly's positional integrity.
Implementation Method 1
the tab is formed of a resilient material and is biased radially inward to slide along ramp surfaces defined between the protrusions; the ramp surfaces are configured to permit ratcheting of the tab in a tightening direction of the nut while inhibiting the nut from rotating in a loosening direction of the nut
Implementation Method 2
The tab is formed of a resilient material and is biased radially inward
Data Source
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AI summary
A connector assembly includes a first member, a threaded shaft, a nut, a set of first teeth, a set of second teeth, and a tab. The threaded shaft is disposed about an axis. The nut is threadably engaged with the threaded shaft. The nut includes a plurality of radially outward extending protrusions. The first teeth face axially and are non-rotatably coupled to the first member. The second teeth are configured to mate with the first teeth. The second teeth are coupled to the threaded shaft for axial movement relative to the threaded shaft and for common rotation with the threaded shaft. The tab is non-rotatable relative to the first member. The tab engages the protrusions to inhibit rotation of the nut relative to the first member.