Ejection Port Cover Multifunctional Pin Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The standard ejection port cover assembly for firearms, particularly AR-15 style, faces challenges during installation and removal due to tolerance issues, small and difficult-to-handle C-clip, and torsion spring problems, leading to potential malfunctions and difficulties in cleaning and maintenance.
Innovation Solution
A tool-less ejection port cover assembly featuring a fixed pin, a spring-loaded pin, and a torsion spring that biases the cover towards an open position, allowing for tool-less installation and removal without specialized tools, with a polymer construction that provides a secure seal and easy identification of wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the standard ejection port cover assembly is used with C-clip and torsion spring, then the cover can be retained on the firearm, but the C-clip is small and difficult to handle for installation and removal
Solution Approach 1:
The patent removes the C-clip from the retention mechanism entirely, extracting the problematic small component that was difficult to handle. The spring-loaded pin replaces the C-clip function, allowing tool-less installation and removal without the small retaining clip.
Solution Approach 2:
The spring-loaded pin automatically engages with the receiver opening and lock groove, serving its own retention function without requiring a separate C-clip. The spring mechanism provides automatic engagement and retention, eliminating the need for manual C-clip installation.
2Reliability
If the standard ejection port cover assembly is used with torsion spring, then the cover can be biased to open position, but the spring can slip past the receiver when out-of-tolerance
Solution Approach 1:
The patent introduces a groove in the receiver and a corresponding protrusion on the spring-loaded pin as intermediary features. These features act as mechanical guides and stops, ensuring the spring remains properly positioned on the pin and cannot slip past the receiver, even when tolerance variations occur.
Solution Approach 2:
The groove and protrusion features are pre-configured into the receiver and spring-loaded pin during manufacturing. This preliminary action ensures proper alignment and retention of the spring mechanism before assembly, preventing misalignment and slippage during operation.
3Strength
If the steel cover plate is used, then the cover can seal the ejection port, but the thin metal stamping can sustain detrimental deformation in use
Solution Approach 1:
The patent transitions from a thin metal stamping to a composite construction consisting of a polymer cover body with an integrated spring-loaded pin mechanism. This composite design provides the necessary strength and deformation resistance while maintaining the sealing function of the ejection port cover.
Solution Approach 2:
The cover assembly is segmented into distinct functional components: the polymer cover plate for sealing, the spring-loaded pin for retention, and the groove/protrusion features for positioning. This segmentation allows each component to be optimized for its specific function, with the polymer providing deformation resistance.
4Reliability
If the detent mechanism is permanently installed into the steel cover plate, then the cover can be retained in closed position, but detailed cleaning becomes difficult when grit enters the system
Solution Approach 1:
The patent extracts the detent mechanism from the cover plate and relocates it to the spring-loaded pin assembly. This extraction allows the detent features to be accessed and cleaned separately from the cover plate, making maintenance and cleaning much easier when grit contamination occurs.
Solution Approach 2:
The retention mechanism is segmented into the spring-loaded pin with its detent features and the cover plate with its lock groove. This segmentation allows the pin assembly to be removed and cleaned separately, providing access to all surfaces for thorough cleaning without disassembling the entire cover mechanism.
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
Enables easy and tool-less installation and removal of the ejection port cover, maintains a secure seal, and facilitates maintenance by preventing deformation and ensuring reliable operation.
Implementation Method 1
a torsion spring configured to apply a torsional bias to the user interface surface and to bias the spring-loaded pin away from the fixed pin along a common axis
Data Source
AI summary
Systems, methods, and apparatus for an ejection port cover with a multifunctional pin. In one embodiment, a fixed pin and a spring-loaded pin both mate with hinge openings at ends of the ejection port. The spring-loaded pin can be longitudinally biased by a spring, such as a torsion spring. This same spring can perform biasing of the ejection port cover toward an open position as well as biasing of a flag extending from the spring-loaded pin into a locked position when the ejection port cover is not installed.