Explosively Driven Fastener Tool with Positive Stop Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tools for applying explosively driven fasteners lack a positive stop mechanism and are not springy when fully energized, leading to inefficiencies and potential misfires.
Innovation Solution
A spring-energized tool with a positive stop mechanism, featuring a firing pin holder biased by a firing spring, a reset sleeve with a reset spring, and a trigger ball system to ensure precise alignment and controlled firing of the fastener.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a spring-energized mechanism is used to drive the firing pin, then the tool can achieve sufficient force to detonate the explosive load, but the tool becomes less reliable due to spring variability and lack of positive stop
Solution Approach 1:
The tool pre-compresses the firing spring during the cocking phase before firing is initiated. The operator pushes the tool forward to compress the firing spring, storing energy in advance. This preliminary action ensures that when the trigger is pulled, the already-compressed spring immediately drives the firing pin with sufficient force to detonate the explosive load, eliminating the need for spring force generation during the critical firing moment.
Solution Approach 2:
A positive stop mechanism is introduced as an intermediary between the spring-driven firing pin and the firing pin guide. This stop consists of a cam surface on the firing pin holder that engages with a corresponding stop surface on the firing pin guide. The positive stop ensures precise alignment and consistent positioning of the firing pin tip relative to the explosive load, compensating for any variability in spring compression and ensuring reliable detonation.
2Ease of operation
If the tool is designed to be compact and portable, then ease of operation is improved, but the internal components cannot form a solid stack, leading to misalignment and misfires
Solution Approach 1:
The tool is divided into modular segments: an outer cover, a trigger body, a firing pin holder, and a nosepiece. Each segment contains specific components that can be independently manufactured and assembled. The firing spring is contained within the trigger body, the positive stop mechanism is integrated into the firing pin holder, and the explosive load is held in the nosepiece. This segmentation allows for compact packaging while maintaining precise alignment through dedicated locating features in each segment.
Solution Approach 2:
The positive stop mechanism acts as an intermediary that ensures precise alignment between the firing pin and the explosive load despite the compact, segmented design. The cam surface on the firing pin holder engages with the stop surface on the firing pin guide, creating a deterministic positioning relationship that compensates for tolerances in the segmented components. This intermediary mechanism guarantees that the firing pin tip aligns precisely with the explosive load center upon firing.
3Volume of moving object
If the firing pin holder is allowed to move freely under spring pressure, then the tool can be compact, but the internal elements cannot contact each other to form a solid stack, reducing reliability
Solution Approach 1:
The operator performs a preliminary cocking action by pushing the tool forward, which compresses the firing spring and moves the firing pin holder into its forward position. During this cocking phase, the firing pin holder is pushed forward against the nosepiece, establishing initial contact between internal elements. This preliminary action ensures that when firing occurs, all internal components are already in their correct positions and form a solid stack, eliminating the need for excessive tool length to achieve component contact.
Solution Approach 2:
The positive stop mechanism serves as an intermediary that ensures reliable contact between the firing pin holder and the firing pin guide. The cam surface on the firing pin holder engages with the stop surface on the guide, creating a deterministic contact point that ensures the firing pin tip is precisely positioned against the explosive load. This intermediary contact mechanism guarantees component reliability while allowing the tool to remain compact.
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 tool ensures consistent and reliable installation of explosively driven fasteners by providing a solid stack of internal components and a positive stop, enhancing operational efficiency and safety.
Implementation Method 1
A firing spring is arranged to bias the firing pin holder distally with respect to the trigger body
Implementation Method 2
A reset spring is mounted around the firing pin guide and abuts the outer arcuate face of the reset sleeve. The reset spring biases the reset sleeve distally
Implementation Method 3
A trigger ball and a trigger ball spring are mounted transversely in the firing pin holder. The trigger ball is biased radially outward from within the firing pin holder
Implementation Method 4
the firing pin strikes the explosive load causing the explosive load to explode and drive the nail out of the nosepiece
Data Source
AI summary
A spring tool for actuating explosive fasteners for driving nails into a substrate is disclosed. For the tool to operate at its maximum potential the firing pin guide should be pushed securely against the rear of the fastener and the tip of the fastener should be pushed securely against the substrate. The action of the operator pushing the tool forward to actuate the tool moves the trigger body forward while compressing the firing spring until the trigger body travels the exact distance needed to release the trigger ball. The trigger body must also be in optimal rotational orientation with the tool and means for accomplishing the alignment is disclosed.