IP Verse

Firearm safety assembly including a lever detent spring

Patent No. US9448023 (titled "Firearm safety assembly including a lever detent spring") on Jul 16, 2014. The application was issued on Sep 20, 2016.

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Technical Landscape

In the early 2010s when ’023 was filed, firearm safety mechanisms were typically implemented using multi-component spring-and-plunger systems or complex internal linkages. At a time when systems commonly relied on coiled compression springs housed within deep cylindrical bores in the frame, the integration of tactile feedback and positive retention often required high-precision machining of multiple small, discrete parts. Hardware constraints of the era made the development of low-profile, ambidextrous controls non-trivial, as traditional detent architectures often increased the lateral width of the firearm or required significant internal volume that competed with the space required for trigger groups and magazine wells.

Prosecution Position

The disclosed invention represents a technical advancement through an architectural shift in detent design, utilizing a pivotally coupled detent spring that operates under compression substantially aligned with the major plane of the firearm frame. This integration enables a two-position toggle mechanism that achieves positive feedback and prevents 'perching' between states without the need for traditional plunger housings. By utilizing a spring that pivots relative to a lever at an assembly pivot point, the system overcomes the constraint of mechanical bulk, allowing the safety assembly to be housed within a shallow frame recess. This structural solution achieves a high degree of reliability and tactile response while reducing the total part count and simplifying the manufacturing process through the use of components like stamped sheet metal springs.

Claims

The patent contains a total of 20 claims, with claims 1, 11, and 19 serving as the independent claims. These independent claims focus on the mechanical configuration of a firearm safety assembly, specifically detailing a lever and detent spring system pivotally coupled to a frame to manage force vectors and rotational movement during operation. The dependent claims serve to further define the physical characteristics and operational parameters of the assembly, such as the specific geometry and material of the detent spring, the inclusion of secondary levers and links, and the precise force magnitudes or feedback mechanisms generated during the transition between safety positions.

Key Claim Terms New

Definitions of key terms used in the patent claims.

Term (Source)	Support for Specification	Interpretation
Assembly pivot point (Claim 1, Claim 11)	The safety assembly may also include a detent spring pivotally coupled to the frame and in contact with the link and/or the first lever to allow the detent spring and first lever to pivot relative to each other. The detent spring has a maximum compression force when the assembly pivot point is in line with the first lever and detent spring pivot points (relative to the frame), referred to herein as a mid-stroke position. In this manner, the assembly is difficult to maintain in the mid-stroke position, thereby providing the benefit of having a mechanism that avoids perching between the two distinct positions.	The point of contact where the detent spring and the first lever (or a link connected to the lever) meet and rotate relative to one another.
Detent spring (Claim 1, Claim 11, Claim 19)	The functioning detent spring may be one part and the properties of the detent spring (e.g., the material, shape, hardness, spring constant, etc.) may be customized as desired to adjust the properties of the safety assembly. In some embodiments, the detent spring may be under compression (or in tension) in the safety assembly, thereby providing the assembly with two distinct positions—a first position (e.g., a fire position) and a second position (e.g., a safe position). The detent spring may be constructed to fit partially or completely within a recess in a firearm frame, such that it adds minimal or no width to the firearm frame.	A single-part spring component that is pivotally anchored to the firearm frame and provides biasing force to the safety assembly through compression or tension.
Force vector (Claim 11)	In a first assembly position, the force vector at the assembly pivot point is in a first direction; and wherein in a second assembly position, the force vector at the assembly pivot point is in a second direction substantially opposite the first direction. The compression force provides two distinct positions, such as a fire position and a safe position, and may hinder the safety assembly from perching between the positions. The safety assembly may provide positive feedback when toggling between the fire and safe positions, which may be increased by increasing the pre-compression of the detent spring.	The directional magnitude of energy exerted by the compressed detent spring at the point of contact with the lever or link, which changes orientation to hold the assembly in different positions.
Link (Claim 19)	The assembly 200 in this embodiment includes a first lever 210, a second lever 220, a detent spring 230, and a linking bolt 240 connecting the first lever 210 and the second lever 220. The contact between the detent spring and the first lever may be direct or indirect (e.g., where the detent spring is making contact with a link connected to or in contact with the first lever). When the assembly is installed on a firearm frame, the detent spring is in contact with the linking bolt and/or the first lever, putting the detent spring in compression.	A connecting component, such as a linking bolt, that joins a first lever to a second lever and serves as the contact interface for the detent spring.
Major plane of the frame (Claim 1)	The detent spring is under compression, the compression force in a direction substantially aligned with a major plane of the frame. The detent spring may be configured to fit within a recess in a firearm frame, such that it does not add any width to a fully assembled firearm. In such embodiments, the detent spring, which may be the only functioning part of the safety assembly, may add minimal or no width to the firearm frame.	The primary flat surface or longitudinal orientation of the firearm frame, along which the compression force of the detent spring is directed to minimize the assembly's width.
Two-position lever detent assembly (Claim 11)	The compression force provides two distinct positions, such as a fire position and a safe position, and may hinder the safety assembly from perching between the positions. Although the two-position lever detent assembly is primarily disclosed in the context of a safety assembly for a firearm, the assembly as variously described herein may be used in other contexts. For example, the assembly may be used for a firearm fire selector or more generally as a toggle switch or two-position lever detent mechanism for any application or context.	A mechanism, such as a safety or fire selector, that utilizes spring force to toggle between and remain in two distinct operational states (e.g., 'safe' and 'fire') without stopping in between.

Patent Summary

Litigation Cases New

US Latest litigation cases involving this patent.

Case Number	Filing Date	Title
4:25-cv-00299	Jun 6, 2025	Abc Ip, Llc V. Harrison Gunworks Llc

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US9448023

Application Number: US14333246A
Filing Date: Jul 16, 2014
Publication Date: Sep 20, 2016
External Links: Slate, USPTO , Google Patents