Striking Tool Metal Ring Members Prevent No-Load Strokes
Solution Overview
Problem
Existing striking tools, such as electric hammers and hammer drills, face issues with preventing no-load strokes due to wear and deterioration of elastic members like O-rings, which fail to provide sufficient resistance over time.
Innovation Solution
Incorporating at least two metal ring members in the tool holder between the intermediate member and the striker, allowing them to move in a front-rear direction, effectively restricting the intermediate member's movement and preventing no-load strokes by creating a smaller bounce distance and applying resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an O-ring is used to prevent no-load strokes, then the no-load stroke prevention function is initially effective, but the O-ring wears and deteriorates after repeated contact, reducing its resistance and failing to prevent no-load strokes
Solution Approach 1:
The patent replaces the durable but ineffective elastic member (O-ring) with inexpensive metal ring members that can be easily replaced. The metal rings serve as sacrificial components that wear instead of the intermediate member, providing a cost-effective solution where low-cost components are intentionally designed to be replaceable while protecting critical components.
Solution Approach 2:
The patent changes the material parameter of the ring members from elastic material (O-ring) to metal material. This parameter change transforms the mechanism from elastic deformation-based resistance to friction-based resistance, where the metal rings provide sufficient frictional resistance to prevent no-load strokes without the wear and deterioration issues of elastic materials.
2Reliability
If multiple ring members are added to restrict intermediate member movement, then no-load stroke prevention is improved, but the device complexity increases
Solution Approach 1:
The patent divides the single resistance-providing component into multiple segment ring members (first ring member and second ring member). These segmented rings work together to provide progressive resistance against the intermediate member, with each ring serving a specific position and function in the resistance mechanism.
Solution Approach 2:
The patent introduces ring members as intermediary components between the intermediate member and the tool holder wall. These intermediary rings provide the resistance function without requiring direct contact between the intermediate member and the tool holder, allowing for adjustable and controllable resistance through the ring members.
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 reliably prevents no-load strokes while minimizing component additions and ensuring durability, as the metal ring members maintain effectiveness even after repeated use.
Implementation Method 1
at least two ring members accommodated in the tool holder at a front of the intermediate member and between the tool holder and the intermediate member in a manner movable in a front-rear direction, wherein at least one of the ring members is made of metal
Data Source
AI summary
A striking tool restricting movement of an intermediate member toward a striker reliably prevents no-load strokes. A hammer drill includes a cylindrical tool holder holding a tip tool, a motor, a piston that reciprocate with rotation from the motor, a striker that reciprocate in cooperation with the piston, an intermediate member reciprocably accommodated in the tool holder between the striker and the tip tool and in contact with a rear end of the tip tool at a normal strike to indirectly transmit a strike from the striker to the tip tool, and at least two ring members that move in a front-rear direction accommodated in the tool holder at a front of the intermediate member between the tool holder and the intermediate member. At least one ring member is made of metal.