Rocker Spring Assembly With Polymeric Restrictor for Quiet Motion
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Solution Overview
Problem
Existing rocker spring assemblies for furniture members suffer from frictional noise due to metal limit rods and require complex forming operations for assembly, which can lead to inefficiencies and noise during rocking motion.
Innovation Solution
A rocker spring assembly design featuring bracket members with coiled springs and a restrictor bolt assembly, where sleeve members in sliding contact with the brackets and a fastener through a sleeve bore retain the springs, allowing for balanced operation and noise reduction by using polymeric materials to prevent metal-to-metal contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal limit rods with stop members are used to restrict spring movement, then the structural strength and durability are improved, but frictional noise is generated during rocking motion
Solution Approach 1:
A polymeric restrictor member is introduced as an intermediary component between the metal bracket members and the springs. This restrictor member has a T-shaped cross-section with a vertical leg that contacts the springs and a horizontal flange that contacts the bracket member, preventing direct metal-to-metal contact and eliminating frictional noise while maintaining structural strength
Solution Approach 2:
The restrictor member is made of polymeric material that combines the benefits of strength, noise reduction, and friction reduction. The composite material approach allows the restrictor to provide structural support while simultaneously eliminating the harmful frictional noise generated by metal contact
2Adaptability or versatility
If stop members are formed on limit rods by stamping operation after installation, then the assembly flexibility is improved, but complex forming operations are required
Solution Approach 1:
The restrictor member is pre-formed with the T-shaped cross-section including the horizontal flange feature before installation. This preliminary formation of the restricting feature eliminates the need for post-installation stamping or forming operations, simplifying manufacturing while maintaining assembly flexibility
Solution Approach 2:
The restrictor member is designed as a separate, pre-formed component with integrated features (T-shaped cross-section) that can be independently manufactured and then assembled. This segmentation allows each component to be optimized separately and assembled without complex forming operations
3Ease of operation
If limit rods are positioned outside both springs, then the spring operation freedom is improved, but the device complexity increases
Solution Approach 1:
The restrictor member is positioned between the two springs and serves as a single centralized component that restricts the movement of both springs simultaneously. This merging approach consolidates what would otherwise require two separate limit rods, reducing assembly complexity while maintaining spring operation freedom
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 design reduces frictional noise and simplifies assembly by using polymeric sleeve members and a central restrictor bolt assembly, allowing for balanced force distribution and smoother rocking motion without the need for complex forming operations.
Implementation Method 1
one of the springs is extended with respect to the other spring. A biasing force of the extended spring helps to return the furniture member to a neutral position
Implementation Method 2
The use of metal limit rod material can result in frictional noise
Data Source
AI summary
A furniture member rocker spring assembly includes first and second bracket members arranged in mirror image configuration. First and second springs are positioned between and in direct contact with each of the first and second bracket members. A restrictor bolt assembly is positioned between the first and second springs. The restrictor bolt assembly includes at least one sleeve member received in an aperture of the first and second bracket members. The sleeve member is in sliding contact with the first and second bracket members. A fastener extends through a sleeve bore of each of the first and second sleeve members. The fastener retains the first sleeve member in contact with the second sleeve member.