Multi-piece bolt assembly for reducing peak recoil in blowback firearms
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Solution Overview
Problem
Blowback type firearms with one-piece bolts generate high peak recoil forces, resulting in undesirable felt recoil for users, which existing designs fail to adequately mitigate.
Innovation Solution
A multi-piece bolt assembly featuring a bolt with a dead blow weight assembly, comprising a dead blow weight and a dead blow top member, which are independently movable and interact under recoil to distribute the recoil force, reducing the peak felt recoil experienced by the user.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a one-piece bolt is used in blowback type firearms, then the structure is simple and reliable, but the peak recoil force is high causing undesirable felt recoil
Solution Approach 1:
The bolt is divided into multiple components: a bolt body, a dead blow weight assembly (including a dead blow weight and dead blow top member), and a recoil spring. The dead blow weight assembly is slideably mounted to the bolt and can move independently rearward and forward under recoil forces. This segmentation allows the bolt to distribute recoil energy across multiple moving parts, reducing the peak recoil force transmitted to the user while maintaining the overall blowback operating system simplicity.
2Object-affected harmful factors
If a multi-piece bolt assembly with dead blow weight is used, then the peak recoil force is reduced, but the device complexity increases
Solution Approach 1:
The dead blow weight assembly acts as a cushioning element that absorbs and distributes recoil energy. When the firearm is discharged, the dead blow weight moves rearward independently of the bolt, creating a two-stage felt recoil force with lower peak magnitude. The recoil spring then acts on the dead blow weight assembly to return it forward, biasing the bolt toward the closed breech position. This beforehand cushioning mechanism reduces the harmful peak recoil force while the modular design keeps the complexity manageable.
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 multi-piece bolt assembly effectively reduces the magnitude of peak recoil forces, providing a more comfortable shooting experience by distributing the recoil energy through a two-stage mechanism, while maintaining the overall recoil energy of the firearm.
Implementation Method 1
blowback bolts form a closed but not a mechanically locked breech because they lack the radial bolt lugs and mating lugs formed in the receiver or barrel necessary to create a locked breech like the foregoing firearms. Instead, bolts used in blowback type operating systems rely on inertia created by the weight of the bolt and a forward spring-force applied to the bolt in order to maintain a closed breech during firing.
Implementation Method 2
A recoil spring acts on the dead blow weight assembly, which in turn biases the bolt forward towards a closed breech position.
Data Source
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AI summary
A bolt assembly for firearms utilizing a blowback type operating system. The bolt assembly comprises a non-rotatable bolt slideably disposed in the receiver for forward and rearward movement and a dead blow weight assembly slideably coupled to the bolt. The dead blow weight assembly may be two-piece comprising a dead blow weight and dead blow top member. These parts are separate components movable independently of each other, but functionally interacting and cooperating under recoil after discharging the firearm to eject a spent cartridge casing and chamber a new cartridge as the action is reset. When the firearm discharged, a two-stage felt recoil force is generated by this mechanism, thereby advantageously producing peak forces which are less in magnitude than the single strong felt recoil force experienced by users with conventional one-piece bolt used in many blowback type firearms.