Staked Gas Key Assembly for Higher-Torque Bolt Carrier Fastening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for securing the gas key to the bolt carrier in autoloading rifles face issues such as loosening due to adhesive bonding, additional component complexity, and reduced torque capacity, leading to potential malfunctions and increased maintenance.
Innovation Solution
A bolt carrier assembly with a gas key fastened using screws, where the screws are secured through staking at a distance from the minimal wall thickness, creating a form- and force-fitting connection, utilizing a staking punch to deform the side wall of the gas key, allowing for increased torque and preventing unintentional loosening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive bonding is used to secure screws, then loosening is prevented, but the screw lock wears out over time due to thermal, mechanical or chemical stress and loses its effect
Solution Approach 1:
The patent replaces the chemical adhesive bonding system with a mechanical staking system. The staking punch deforms the gas key material to create a mechanical interlock with the screw head, eliminating the need for adhesive bonds that deteriorate under thermal, mechanical, and chemical stress. This mechanical substitution provides a more durable connection that does not wear out over time.
Solution Approach 2:
The patent changes the physical state and properties of the gas key material through localized plastic deformation during the staking process. By applying controlled force with the staking punch, the material undergoes permanent deformation to form a mechanical lock, transforming the connection mechanism from chemical adhesion to mechanical interlocking with enhanced durability.
2Reliability
If additional components like O-rings are used for securing, then the connection is improved, but the assembly complexity increases
Solution Approach 1:
The patent extracts and eliminates the need for additional securing components such as O-rings, key elements, and bridge structures. By implementing the staking process that creates a direct mechanical interlock between the gas key and screw head, the design removes unnecessary intermediate components, thereby reducing assembly complexity while maintaining connection reliability.
Solution Approach 2:
The patent merges the securing function into the existing gas key structure itself. The staking process creates an integrated mechanical lock that is part of the gas key, eliminating the need for separate securing components. This merging of functions reduces the number of parts and simplifies the overall assembly.
3Reliability
If center punch is used to stake the screw, then the screw is secured against loosening, but a sufficient wall thickness has to be provided which results in thinner screw diameters and less torque
Solution Approach 1:
The staking process creates localized plastic deformation at specific points on the gas key, concentrating the mechanical lock in precise locations around the screw head. This localized approach provides secure fastening without requiring reduced screw diameters, as the strength is concentrated where needed rather than requiring overall wall thickness reduction.
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 staking method enhances the torque capacity of the fastening screws, reducing maintenance intervals and ensuring a reliable connection without additional components, thus improving the rifle's operational reliability and longevity.
Implementation Method 1
the staking is formed at a depth in the side wall that is predetermined by pushing a staking punch against it
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A bolt carrier assembly (20) for a firearm (10) having a barrel (11), comprising a bolt carrier (21) and a gas key (30) having a side wall (33) and a guide surface (32). On the gas key (30) at least one hole (34) for receiving in each case one fastening element (40) per hole (34) is formed along a median plane (301), and the hole (34) comprises a bore (341) which extends along a hole axis passing through a central point (345) and a recess (342) in the upper region. The gas key (30) comprises a region of minimal wall thickness formed along a normal (36), which intersects the hole axis, to the median plane (301) between recess (342) and side wall (33). The gas key (30) is fastened to the bolt carrier (21) by means of at least one fastening element (40), wherein for securing the at least one fastening element (40) at least one staking (60) is comprised of at least one side wall (33) of the gas key (30) and wherein the at least one staking (60) is formed at a depth in the at least one side wall (33) and the at least one staking (60), as seen in the firing direction (92), is spaced apart from the region of minimal wall thickness.