Firearm Lower Receiver with Slanted Feed Ramp and Eccentric Magazine Receptacle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lower receivers for firearms, particularly repeater rifles, face issues such as material stress cracks, lack of a feed ramp for guiding cartridges, unprotected magazine securing levers, unadjustable actuation force, manufacturing tolerances leading to noise, and incompatibility with conventional metal cartridge magazines due to eccentric feed arrangements.
Innovation Solution
A metal lower receiver with a distinct slanted feed ramp, a protected and adjustable magazine securing lever made of high-strength plastic, adjustable spring bores for actuation force, and eccentric magazine receptacle design to accommodate conventional metal cartridge magazines, reducing stress cracks, enabling proper cartridge guidance, preventing accidental actuation, adjusting actuation force, and minimizing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the lower receiver is made of plastic material, then the weight is reduced and manufacturing is easier, but stress cracks occur at screw connections under load and with age
Solution Approach 1:
The lower receiver is made from a composite material consisting of at least 30% glass fiber by weight, combining the strength of glass fibers with a plastic matrix to achieve both high strength and ease of manufacturing. This composite structure prevents stress cracks at screw connections while maintaining the benefits of plastic material processing.
2Ease of operation
If no distinct feed ramp is provided, then the lower receiver structure is simpler, but cartridges cannot be properly guided into the cartridge chamber
Solution Approach 1:
The feed ramp is integrated into the lower receiver as a built-in structural feature rather than a separate component. This merging of functions allows the lower receiver to guide cartridges into the chamber while maintaining a simple overall structure, eliminating the need for additional feed ramp parts.
3Ease of operation
If the magazine securing lever projects from the lower receiver for easy operation, then the ease of operation is improved, but accidental actuation can occur during use
Solution Approach 1:
The magazine securing lever is positioned in a locally recessed area of the lower receiver, creating a protected zone that shields the lever from accidental contact. The lever maintains its operational accessibility while the local geometric modification prevents unintended actuation during handling.
4Adaptability or versatility
If the magazine receptacle is arranged centrally relative to the symmetry axis, then the structural symmetry is improved, but conventional metal cartridge magazines with eccentric feed cannot be used
Solution Approach 1:
The magazine receptacle is deliberately positioned asymmetrically relative to the lower receiver's symmetry axis, specifically offset to accommodate the eccentric feed mechanism of conventional metal cartridge magazines. This asymmetric arrangement enables compatibility with standard metal magazines while the lower receiver maintains its overall symmetric structure.
Data Source
AI summary
A metal lower receiver for a firearm has a receiver body. A magazine receptacle is disposed in the receiver body and adapted to receive a removable cartridge magazine. A magazine securing lever is disposed on the receiver body. The receiver body has a feed ramp positioned at a slant relative to a barrel of the firearm. The feed ramp is adapted to lift during reloading of the firearm a projectile tip of a cartridge from a removable cartridge magazine inserted into the magazine receptacle and to guide the cartridge in a direction of a cartridge chamber disposed in the barrel.