Anti-Rattle Sleeve Deformation for Hinge Joint Stability
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Solution Overview
Problem
Assembling hinge joints with plastic sleeves is challenging due to difficulty in controlling the clamp load and compressive force, leading to issues with gaps and rattles, and handling small parts is error-prone.
Innovation Solution
An anti-rattle sleeve with a split end and flange end, featuring retention features that deform to reduce relative motion between brackets, using a semi-flexible material like ZYTEL MT409, and incorporating bumps to absorb compressive forces and prevent over-stressing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a threaded fastener is used to assemble the hinge joint, then the clamp load can be applied to compress the sleeve and washers, but the torque applied to the fastener must be closely controlled to prevent overstressing the plastic and gaps in the hinge joint are not adequately closed to prevent squeak and rattle issues
Solution Approach 1:
The patent changes the physical state of the sleeve from rigid to semi-flexible by selecting material with appropriate durometer (40-70 shore D). This parameter change allows the sleeve to deform and conform under compression, automatically achieving gap closure and rattle prevention without requiring precise torque control during assembly.
Solution Approach 2:
The patent employs a semi-flexible sleeve made of polymer material that can bend and deform. The flexibility of this shell allows it to adapt to slight variations in hole alignment and bracket surfaces, ensuring proper contact and elimination of gaps that cause squeak and rattle, while simplifying the assembly process.
2Reliability
If the plastic sleeve is compressed to close gaps in the hinge joint, then squeak and rattle issues are prevented, but the plastic used to form sleeve may be overstressed by the clamp load
Solution Approach 1:
The patent changes the mechanical properties of the sleeve by selecting polymer material with specific durometer (40-70 shore D), making it semi-flexible rather than rigid. This allows the sleeve to undergo elastic deformation under clamp load, closing gaps effectively while distributing stress to prevent overstressing and failure of the plastic material.
Solution Approach 2:
The semi-flexible nature of the sleeve acts as a cushioning element that absorbs and distributes the clamp load before it reaches critical stress levels in the plastic. The material's elasticity provides a buffer that prevents sudden stress concentration and potential failure during assembly.
3Ease of manufacture
If small washer and sleeve parts are handled during assembly, then the hinge joint can be assembled, but error proofing the presence of these small parts is difficult
Solution Approach 1:
The patent combines the sleeve with the washer into a single integrated component. This merging eliminates the need to handle and assemble separate small parts, reducing the risk of missing components or assembly errors while maintaining the functional benefits of both the sleeve's flexibility and the washer's load distribution.
Solution Approach 2:
The integrated component performs multiple functions simultaneously: it provides electrical isolation, distributes clamp load, prevents rattles, and serves as a structural element. This multi-functionality reduces the number of separate parts needed, simplifying assembly and improving error proofing.
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 sleeve effectively reduces relative motion and prevents rattles by deforming to create an interference fit, ensuring secure assembly and electrical isolation while managing compressive forces, thus enhancing the stability and reliability of hinge joints.
Implementation Method 1
The sleeve is made of a semi-flexible material such as ZYTEL MT409... the sleeve is deformed by the inner surfaces in a manner effective to reduce relative motion between the object bracket and the mounting bracket when compressed therebetween
Data Source
Figure 1A~1B
Figure 2
Figure 3~4
AI summary
An anti-rattle sleeve (10) that includes a retention feature (24) on a split end (22) that extends radially from the body portion (18) and a slot (26) configured to allow the retention feature (24) to be pressed through an opening (20). The sleeve (10) also includes a flange portion (30) opposite the split end (22) that includes an inner bump (36) configured to contact a surface of an object bracket (12) and an outer bump (40) configured to contact a surface of a mounting bracket (14). The inner bump (36) and the outer bump (40) are located relative to the slot (26) such that the sleeve (10) is deformed by the brackets in a manner effective to reduce relative motion between the object bracket (12) and the mounting bracket (14) when compressed between the brackets.