Pneumatic Tool Firing Control Device Valve Mechanism
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Solution Overview
Problem
Conventional pneumatic tools face issues with wear and air-tightness loss due to the locking piston and control piston interaction, leading to inconsistent fastener firing performance.
Innovation Solution
A firing control device with a flow path unit, conditioning valve assembly, and switch valve assembly that controls fluid communication between the main and operating chambers, preventing wear and maintaining air-tightness by using a conditioning valve that moves to block or allow fluid communication based on trigger activation timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking piston is used to prevent control piston movement after a predetermined time period, then fastener firing control is achieved, but wear and air-tightness loss occur between the locking piston and housing cap
Solution Approach 1:
The patent replaces the mechanical locking piston system with a valve rod and valve assembly that uses fluid pressure control instead of mechanical latching. The valve rod movably connects to the trigger assembly and controls the first and second control valves through fluid pressure, eliminating the need for a separate locking piston and its associated wear and air-tightness issues.
Solution Approach 2:
The patent removes the locking piston component entirely from the system. Instead of adding a locking mechanism, the design extracts the locking function by using the valve rod's movable connection and the control valves' pressure-based operation to naturally prevent fastener firing unless both trigger and safety member are depressed within the required time window.
2Ease of operation
If the trigger and force transmission element are both depressed to activate the first control valve, then fastener firing is enabled, but the system becomes complex with multiple moving parts
Solution Approach 1:
The patent merges the trigger assembly and safety member into a unified control system where both components must be simultaneously depressed to activate the valve rod. The valve rod's movable connection integrates the functions of multiple control elements, allowing the system to respond only when both the trigger and safety member are engaged within the predetermined time period, simplifying the control logic while maintaining safety.
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 solution ensures reliable fastener firing by preventing wear on the conditioning valve and maintaining air-tightness, allowing for consistent operation and extended tool lifespan.
Implementation Method 1
the valve rod is activated for preventing fluid communication between the main chamber and the operating chamber and for releasing the pressure in the operating chamber so as to fire a fastener
Implementation Method 2
The conditioning valve is moved to block fluid communication between the main chamber and the operating chamber via the flow path unit when the switch valve is continuously activated by a predetermined time period
Implementation Method 3
The switch valve is activated upon the depression of the trigger assembly to prevent fluid communication between the flow path unit and the outside, and to permit the pressure in the casing to move the conditioning valve
Data Source
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AI summary
A firing control device for use in a pneumatic tool (1) includes a flow path unit (2), a conditioning valve (31) and a switch valve (51). The flow path unit (2) is connected to a main chamber (11) and an operating chamber (12) of the pneumatic tool (1). When the switch valve (51) is activated, the pressure in the pneumatic tool (1) is permitted to move the conditioning valve (31). The conditioning valve (31) is moved to permit the fluid communication between the main chamber (11) and the operating chamber (12) via the flow path unit (2) when the switch valve (51) is continuously activated by a predetermined time period.