Split Speed Nut Locking for Fast High-Force Threaded Rod Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing speed nuts require numerous turns to apply high forces to threaded rods, delaying the replacement of critical valve components in high-force valve extraction applications due to their shallow pitch threads.
Innovation Solution
A dual-knuckle speed nut design with axially-extending pins and a torsion arm mechanism allows rapid locking and positioning on a threaded rod, resisting axial forces while enabling easy separation and repositioning, using interdigitating knuckles and a quick release pin system for secure engagement and disengagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a threaded shaft with shallow pitch threads is used to improve resistance to axial force, then axial force resistance is improved, but the number of turns required to move the nut increases significantly
Solution Approach 1:
The nut is divided into two separate halves that can be assembled around the threaded shaft independently and then joined together using hinge pins. This segmentation allows the nut to be positioned rapidly on the shaft without requiring multiple turns, while still engaging the shallow pitch threads for axial force resistance when closed.
Solution Approach 2:
The nut transitions from a static, fully-threaded design to a dynamic, two-state design where the halves can be rapidly opened and closed. The hinge pin mechanism enables quick transition between open (for rapid positioning) and closed (for force engagement) states, resolving the time-force contradiction.
2Force
If a conventional nut is used to provide high forces on the threaded rod, then force application is improved, but the nut requires numerous turns to position, delaying component replacement
Solution Approach 1:
The two nut halves are pre-configured with hinge pins and knuckle interfaces that enable rapid assembly around the threaded shaft before engagement. This preliminary positioning action eliminates the need for multiple turning operations, allowing immediate force application when closed.
Solution Approach 2:
By segmenting the nut into two halves that can be independently positioned and then quickly joined, the system enables rapid productivity improvement while maintaining the full force application capability of a conventional nut when closed.
3Ease of operation
If the nut halves are designed to freely separate when force is removed, then ease of disassembly is improved, but resistance to separation forces during use may be compromised
Solution Approach 1:
The hinge pin mechanism replaces complex threading engagement for closure with a simple mechanical pin insertion system. The knuckles provide geometric constraint that resists separation forces during use, while the pin allows rapid, tool-free opening by simply withdrawing the pin, achieving both reliability and ease of operation.
Data Source
AI summary
A speed nut provides a separable housing, when closed, defining an internally threaded cavity for engaging a threaded shaft, and when open, allowing movement of the speed nut along the shaft without engagement of the threads. Interdigitated knuckles on the housing portions provide robust resistance against axial shifting when the nut is used to apply axial force to the threaded shaft. The knuckles may also provide a hinge point allowing the nut to be opened and closed with a simple hinging action and a means for locking the nut portions together through a releasable pin passing through the opposite knuckles.