Piston Sealing Lip Elastic Deformation for Cartridge Venting
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Solution Overview
Problem
Conventional pistons with forward-pointing sealing lips face challenges in achieving reliable venting without a valve mechanism, risking damage to the sealing lip and potential leakage, especially under higher ejection pressures.
Innovation Solution
The piston design incorporates a slight bending deformation around a diametral transverse axis, allowing venting through diametrically opposite areas, and a modified setting tool concentrates axial thrust on specific points to create this deformation, eliminating the need for a vent valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a forward-pointing sealing lip is used to improve sealing under ejection pressure, then sealing reliability is improved, but automatic venting capability is lost
Solution Approach 1:
The sealing lip is designed with dynamic flexibility, allowing it to deform elastically under setting tool pressure during insertion. This dynamic behavior enables the lip to transition from a sealed state during ejection to a vented state during insertion, resolving the contradiction between maintaining seal reliability and enabling automatic venting.
Solution Approach 2:
The sealing lip's geometric parameters (curvature radius, thickness distribution) are optimized to change its mechanical properties under different loading conditions. The lip maintains contact pressure for sealing during ejection but deforms to create venting channels during insertion when set by the setting tool.
2Ease of operation
If a valve mechanism is added to enable venting, then venting capability is improved, but device complexity and risk of leakage increase
Solution Approach 1:
The venting function is extracted from a separate valve mechanism and integrated into the sealing lip itself. The sealing lip's elastic deformation under setting tool pressure creates venting channels directly, eliminating the need for additional valve components and reducing complexity while maintaining venting capability.
Solution Approach 2:
The sealing lip performs dual functions: sealing during ejection and venting during insertion. The same elastic structure that provides sealing reliability also enables automatic venting when deformed by the setting tool, making the system self-sufficient without requiring separate valve mechanisms.
3Ease of operation
If setting tool fingers are used to push the sealing lip to enable venting, then venting capability is improved, but risk of sealing lip damage increases
Solution Approach 1:
The sealing lip's geometric parameters (curvature radius, thickness distribution) are optimized to change its mechanical properties under different loading conditions. The lip maintains contact pressure for sealing during ejection but deforms to create venting channels during insertion when set by the setting tool.
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
This solution ensures reliable venting without a valve, reducing the risk of sealing lip damage and maintaining a clean seal during ejection, while preventing filling material leakage.
Implementation Method 1
the setting force acting on it creates a slight bending deformation around a diametral transverse axis that causes the piston to be slightly out-of-round
Implementation Method 2
a forward-pointing sealing lip in the front area of the piston, which is pressed more strongly against the inner wall of the cartridge as the ejection pressure increases
Implementation Method 3
the venting function came about automatically because the sealing lips, which are relatively soft to achieve a good seal, are subject to the pressure of the compressed air trapped between the piston and the rear end of the cartridge
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~3b
AI summary
The closing and ejection piston has a piston plate (1) and a cylindrical streamlining (2), where a transition area is formed between the piston plate and the cylindrical streamlining with V-shaped cross-section. A sealing lip (3) is formed on a periphery and contains a stacking ring. Two axial projections are distributed equally on the periphery at the backward facing end surface of the stacking ring. An independent claim is included for a method for inserting a piston in the open rear end of the cartridge.