Friction-Based Vent Plug for Tamperproof Lead Acid Battery Sealing
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Solution Overview
Problem
Existing lead acid batteries face challenges in ensuring tamperproof closure of vent plugs without requiring additional production steps or special tools, as conventional methods are prone to unauthorized opening and risk of hazardous substance spillage.
Innovation Solution
A vent plug design featuring an annular body with a smooth head portion and a threaded body portion, where the torque for insertion is transmitted by friction only, preventing mechanical engagement with tools and ensuring the plug can only be unscrewed by the same appliance used for insertion, thus maintaining the battery's integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional vent plugs with interlock screw drive systems are used, then the vent plugs can be opened without damaging the surface, but the risk of unauthorized opening and hazardous substance spillage increases significantly
Solution Approach 1:
The patent replaces the conventional mechanical interlock screw drive system with a friction-based closure mechanism. The vent plug head is designed without interlock features, relying solely on friction between the plug surface and the tool to transmit tightening torque. This substitution eliminates the risk of unauthorized opening while maintaining controlled operability for authorized personnel with appropriate tools.
Solution Approach 2:
The patent changes the surface parameter of the vent plug head by providing a roughened or textured surface treatment. This surface modification increases the friction coefficient between the plug and the tool, enabling effective torque transmission without mechanical interlocks. The parameter change from smooth to rough surface directly addresses the tamperproof requirement while preserving ease of operation for authorized users.
2Reliability
If additional production steps like ultrasonic welding or friction welding are applied to seal vent plugs, then tamperproof closure is achieved, but manufacturing complexity and production time increase
Solution Approach 1:
The patent extracts and eliminates the additional sealing steps (ultrasonic welding, friction welding, labeling) from the production process. By designing the vent plug with a friction-based closure mechanism and smooth head portion, the invention achieves tamperproof closure through the basic screwing action alone, removing the need for separate welding or sealing operations.
Solution Approach 2:
The vent plug design enables self-sealing through its own structural features. The smooth head portion and friction-based closure mechanism allow the plug to maintain its sealed state inherently, without requiring external welding equipment or additional sealing materials. The system serves itself by using the tightening torque alone to create and maintain the tamperproof closure.
3Reliability
If welded or clipped vent plugs are used to prevent opening, then tamperproof closure is achieved, but the surface of the vent plug or lid may be damaged during installation
Solution Approach 1:
Instead of using welding or clipping methods that attach the vent plug to the lid (external connection), the patent inverts the approach by designing the vent plug head itself to resist tool engagement (internal resistance). The smooth head portion prevents tool engagement, making unauthorized opening difficult without damaging either the plug or lid surfaces during normal operation.
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 allows for the production of tamperproof lead acid batteries on standard assembly lines without additional steps, ensuring the battery cells remain sealed and preventing unauthorized access or spillage of hazardous substances.
Implementation Method 1
the torque required to insert the vent plug in the cover is transmitted between a tool and the vent plug by friction only
Data Source
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AI summary
The invention concerns a vent plug for a filling hole in a cover for a lead acid battery, said vent plug having an annular body with a head portion and a body portion, said body portion having a device for mechanically engaging the vent plug in the filling hole in the cover, wherein the head portion of the vent plug has a smooth surface. The invention also involves a cover for a lead acid battery comprising said vent plugs as well as a lead acid battery comprising said cover.