Firearm Stock Assembly Mating Interfaces for Length Adjustment
Solution Overview
Problem
Current stock and receiver extension combinations face issues with length adjustment due to discrepancies in diameter, leading to friction or loose fitting, affecting firearm performance and stability.
Innovation Solution
A stock assembly system with mating interfaces, including a receiver extension and stock interface, featuring a base portion with position holes and grooves, and a slot portion with an adjustment pin, allowing for secure attachment and adjustable length without radial movement, produced using extrusion manufacturing for improved durability and fit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a telescoping mechanism is used to extend the length of the firearm, then the firearm length can be adjusted, but friction and sticking occur when adjusting the length due to diameter discrepancies between the stock's interior cavity and the receiver extension
Solution Approach 1:
The interface is segmented into multiple functional components: a base portion for positioning, edges for lateral constraint, and grooves for rotational constraint. This segmentation allows each element to address a specific aspect of the adjustment mechanism, eliminating friction and sticking by distributing the mating functions across multiple discrete features rather than relying on a single telescoping interface.
Solution Approach 2:
The edges and grooves act as intermediary elements between the stock's interior cavity and the receiver extension. These intermediaries provide precise geometric constraints that eliminate diameter discrepancies, allowing smooth adjustment without direct contact between the primary mating surfaces that would cause friction.
2Manufacturing precision
If the diameter of the stock's interior cavity is made smaller to reduce clearance, then the fit becomes tighter, but friction and sticking increase during length adjustment
Solution Approach 1:
The interface is divided into multiple constraint elements (base portion, edges, grooves) that collectively achieve precise fitting. This segmentation allows the interface to maintain tight precision without relying on a single reduced-diameter cavity, thereby avoiding the friction and sticking that would result from excessive tightness in a single mating surface.
Solution Approach 2:
The constraint mechanism transitions from a single-dimensional diameter fit to a multi-dimensional constraint system involving lateral edges and rotational grooves. This dimensional expansion allows precise fitting to be achieved through geometric interlocking rather than through reducing the interior cavity diameter, maintaining adjustment smoothness while achieving tight precision.
3Ease of operation
If the diameter of the stock's interior cavity is made larger to reduce friction, then adjustment becomes smoother, but the stock becomes loosely secured with unwanted movement
Solution Approach 1:
The interface is segmented into multiple functional zones: a base portion for positioning, edges for lateral stabilization, and grooves for rotational stabilization. This segmentation allows the interior cavity to maintain a larger diameter for smooth adjustment while the distributed constraint elements provide the necessary security against unwanted movement in multiple directions.
Solution Approach 2:
The stabilization mechanism moves from relying solely on radial diameter fit to incorporating constraints in additional dimensions through edges and grooves. This multi-dimensional constraint system provides secure stabilization against lateral and rotational movement while allowing the primary interior cavity diameter to remain larger for friction-free adjustment.
4Adaptability or versatility
If traditional telescoping mechanisms are used, then length adjustment is possible, but the manufacturing complexity and cost increase due to tight tolerance requirements
Solution Approach 1:
The interface is segmented into multiple standardized features (base portion, edges, grooves) that can be manufactured using conventional processes. This segmentation breaks down the complex tight-tolerance requirement into simpler, more manufacturable geometric elements that can be produced with standard tolerances, reducing manufacturing complexity and cost while maintaining length adjustability.
Solution Approach 2:
The interface design creates universal, multi-functional features that serve multiple purposes: the base portion provides positioning, the edges provide lateral constraint, and the grooves provide rotational constraint. These universal features can be manufactured using standard processes and can be applied across different firearm configurations, simplifying manufacturing while enabling length adjustment.
Data Source
AI summary
Adjusting the length of firearms using stock assembly systems are provided. In one embodiment, a stock assembly comprises: a receiver extension having a first interface configured to mate with a second interface of a stock; the first interface comprising a base portion, a plurality of first edges, and a plurality of first grooves; the second interface comprising a slot portion, a plurality of second edges, and a plurality of second grooves; wherein the plurality of first edges are in contact with the plurality of second grooves and the plurality of first grooves are in contact with the plurality of second edges of the second interface to mate the stock with the receiver extension; and wherein the base portion of the first interface is in contact with the slot portion of the second interface allowing the stock to slide along a horizontal axis of the receiver extension.