Gas Spring Safety Plug for Overtravel Pressure Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas springs in sheet-metal moulding presses face issues with piston blocking or overtravel, leading to safety risks, and current safety systems are unreliable, costly, and complex to install.
Innovation Solution
A one-piece safety plug with a breakable septum and deformable head that discharges gas upon overtravel or overpressure, ensuring reliable and efficient gas release without direct contact with the septum, and is easy to install.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mushroom-shaped safety plug with a blind discharge duct is used, then gas discharge is enabled upon overtravel, but the system becomes unreliable due to accidental breakage of the threaded shank under normal depressurisation conditions
Solution Approach 1:
A breakable septum is introduced as an intermediary element between the piston and the discharge duct. The septum remains intact during normal operation even when the piston contacts the threaded shank, but breaks when exposed to high-pressure gas, enabling controlled discharge only under critical conditions.
Solution Approach 2:
The breakable septum is pre-installed to close the discharge duct before any critical event occurs. This preliminary protective measure ensures that the discharge path remains sealed during normal operation and only opens when the septum breaks under extreme pressure or deliberate action.
2Reliability
If the threaded shank protrudes cantilevered into the cup-shaped body to enable breakage upon piston impact, then overtravel detection is achieved, but the system becomes vulnerable to accidental shank breakage under normal operating loads
Solution Approach 1:
The breakable septum serves as a mediator that absorbs the impact force during normal operation, protecting the threaded shank from breaking under normal loads. The septum is positioned such that it breaks only when subjected to the combined effect of piston impact and high-pressure gas exposure during actual overtravel or critical conditions.
Solution Approach 2:
The system exploits the change in pressure parameters to differentiate between normal operation and critical conditions. During normal operation, pressure remains low and the septum stays intact. During critical conditions, pressure increases dramatically, causing the septum to break and enable gas discharge.
3Reliability
If a breakable septum is introduced to close the discharge duct, then accidental discharge is prevented, but the device complexity and manufacturing cost increase
Solution Approach 1:
The breakable septum is implemented as a thin, flexible membrane that can be easily integrated into the safety plug structure. This thin-film approach minimizes the added complexity while effectively serving as a controllable barrier that breaks only under critical conditions.
Solution Approach 2:
The breakable septum is designed as a simple, inexpensive component that is sacrificed during critical events. Its low cost and simple structure allow it to be easily replaced if needed, while providing reliable gas discharge control during the gas spring's service life.
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 safety plug effectively prevents piston overtravel and overpressure issues while being cost-effective and simple to install, providing enhanced safety and reliability with dual gas discharge mechanisms.
Implementation Method 1
a variable-volume closed chamber, which is filled with a high-pressure gas that tends to maximise the volume of the closed chamber and, therefore, continuously pushes the piston outside of the cup-shaped body
Implementation Method 2
the breakable septum (15) is dimensioned so as to break when a pressure difference between two faces of the septum (15) exceeds a pre-set limit value
Implementation Method 3
the head (11) is moreover structured so as to deform when the pressure of the gas (40) exceeds a second pre-set limit value, so as to allow the release of the pressurised gas from the cup-shaped body (2)
Data Source
Figure 1
Figure 2~6
AI summary
A gas spring (1) comprising: a cup-shaped body (2); a movable piston (3) which is inserted in an axially slidable manner in the cup-shaped body (2) and is coupled to the cup-shaped body (2) in a fluid-tight manner, so as to delimit a variable-volume closed chamber (4) adapted to contain a pressurised gas; and a safety plug (8) provided with a shank (12) which extends in pass-through manner in the bottom wall (10) of the cup-shaped body (2), and protrudes cantilevered within the cup-shaped body (2) so that its distal end can be reached/struck by the movable piston (3) in the case of overtravel; the distal end of the shank (12) having a substantially tubular structure that directly communicates with the closed chamber (4).