Threaded Scissor Pivot Assembly for Low-Friction Locking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing scissor pivot assemblies face challenges in achieving low friction operation while being cost-effective and efficiently assembled, as they often require complex components and high manufacturing costs.
Innovation Solution
A low friction pivot assembly comprising a first and second hub member with threaded surfaces, pawls, and serrated surfaces that engage to provide a secure and smooth rotational connection, allowing for efficient assembly and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pivot assemblies are used to provide a secure connection, then reliability is improved, but friction increases and manufacturing cost increases
Solution Approach 1:
The pivot assembly is divided into separate hub members (first hub member with external threads and second hub member with internal threads) that can be independently manufactured and assembled. This segmentation allows each component to be optimized for its specific function while reducing overall friction through precise manufacturing of individual parts.
Solution Approach 2:
A lock member with pawls acts as an intermediary component between the hub members, providing secure engagement through the pawl-and-ratchet mechanism while allowing the hub members to maintain low-friction rotational surfaces. The lock member mediates between the need for security and the need for low friction.
2Loss of energy
If complex components are used to reduce friction, then friction is reduced, but manufacturing cost increases and assembly complexity increases
Solution Approach 1:
The threaded surfaces on the hub members enable self-aligning and self-securing during assembly. The external threads on the first hub member mate with the internal threads on the second hub member, allowing the components to self-assemble without complex tooling or additional fastening operations, thereby reducing manufacturing cost while maintaining low friction.
Solution Approach 2:
The pivot assembly uses simple, inexpensive threaded components rather than expensive precision-bored or fitted parts. The threaded hub members can be manufactured using standard threading processes, making them cost-effective while still providing low-friction rotation when properly assembled.
3Reliability
If traditional pivot assemblies are used for secure connection, then reliability is improved, but assembly time increases and manufacturing complexity increases
Solution Approach 1:
The hub members are pre-configured with threaded surfaces and the lock member is pre-configured with pawls that correspond to serrations on the hub members. This preliminary configuration allows for rapid assembly where components simply need to be threaded together and locked, eliminating the need for complex alignment procedures or multiple assembly steps.
Solution Approach 2:
The invention replaces complex mechanical fitting and alignment systems with a threaded connection system. Instead of requiring precise manual fitting or specialized assembly tools, the threaded hub members allow for quick, tool-based assembly that maintains reliability while dramatically improving assembly efficiency.
Data Source
AI summary
A low-friction hub assembly for pivotally connecting a pair of scissors or lever-like members employs a pair of cooperative hub members. A first hub member has an exterior threaded surface which threadably engages with an interior threaded surface of the second hub member. Each of the hub members has annular shoulders which engage against opposed annular surfaces of surrounding aligned pivot openings of the scissors. A locking member comprising a pair of opposed pawls engages a serrated surface to lock the subassembly. A throughbore extends through the pivot assembly.