Varying Cross-Section Driver Blade Reduces Piston Impact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing powered-fastener-driving tools face issues with excessive impact force on the piston and cylinder when returning to the pre-firing position, leading to potential damage and misalignment of the driving assembly.
Innovation Solution
The tool incorporates a driver blade with a varying cross-section, which changes the portion of the driver blade receiving opening occupied as the piston moves between positions, allowing controlled air leakage and reducing the air pressure in the return chamber, thereby minimizing the impact force on the piston.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a driver blade with uniform cross-section is used, then the structure is simple and manufacturing is easy, but excessive impact force is generated on the piston and cylinder during return, causing potential damage and misalignment
Solution Approach 1:
The driver blade employs a varying cross-sectional area along its length, where the cross-section is larger at the distal end and smaller at the proximal end. This local variation in geometry allows the blade to maintain structural integrity while controlling air leakage patterns during piston return, thereby reducing impact force on the cylinder without compromising manufacturing feasibility
Solution Approach 2:
The patent changes the geometric parameter of the driver blade by varying its cross-sectional area along the length. This parameter change modifies the air flow characteristics through the driver blade receiving opening, controlling pressure equalization during piston return and reducing harmful impact forces
2Object-affected harmful factors
If a driver blade with varying cross-section is used, then the impact force on the piston is reduced, but the device complexity increases
Solution Approach 1:
The varying cross-section of the driver blade introduces local geometric variation to achieve uniform air leakage control during piston return. This local quality change reduces impact force without requiring additional components or complex mechanisms, thereby limiting the increase in device complexity
3Speed
If air pressure in the return chamber is high, then the piston returns quickly to the pre-firing position, but the impact force on the cylinder increases causing damage and misalignment
Solution Approach 1:
The varying cross-sectional area of the driver blade modifies the air pressure parameter in the return chamber during piston return. By controlling the cross-section variation, the patent achieves a balance between maintaining sufficient return speed and limiting peak pressure to reduce impact force on the cylinder
Solution Approach 2:
The geometric design of the driver blade anticipates the pressure buildup during piston return by providing a varying cross-section that gradually equalizes pressure. This beforehand design prevents sudden pressure spikes that would cause high impact force, effectively cushioning the return impact
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 varying cross-section of the driver blade effectively reduces the impact force on the piston and cylinder upon return, preventing damage and ensuring proper positioning of the driving assembly, thus enhancing the tool's operational reliability.
Implementation Method 1
allowing controlled air leakage and reducing the air pressure in the return chamber, thereby minimizing the impact force on the piston
Data Source
Figure 1A~1C
Figure 2
Figure 3
AI summary
A fastener-driving tool comprising: a cylinder; a driver blade seal that defines a driver blade receiving opening; a driving element (200) including a driver blade (206); and a piston within and movable relative to the cylinder and the driver blade seal and that is attached to the driving element (200) such that the driver blade (206) is slidably received in the driver blade receiving opening, wherein the driver blade (206) has a non-uniform cross-section (WAl, WA2) such that a portion of the driver blade receiving opening occupied by the driver blade (206) changes as the piston moves relative to the cylinder from a first position to a second position.