Asymmetrical Anvil Idle Strike Catcher for Power Chisels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing portable power chiseling tools, such as hammer drills, suffer from idle strikes that cause unnecessary load and inefficiency due to the anvil rebounding and reactivating the striking mechanism, leading to reduced accuracy and efficiency in energy transfer to the work surface, especially under conditions of wear and dust exposure.
Innovation Solution
The tool incorporates a conically shaped idle strike catcher with an asymmetrical end face on the anvil, which tilts and jams in the guide tube, enhancing the stopping effect and preventing unwanted reactivation of the striking mechanism by dissipating kinetic energy through axial offset contact points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the anvil is guided axially with high precision to prevent rebound, then the accuracy of energy transfer is improved, but the guidance components are subject to high wear due to dust and drillings
Solution Approach 1:
The end face of the anvil is made asymmetrical with respect to the catcher surface, creating a deliberate non-coaxial arrangement. This asymmetry causes the anvil to tilt upon contact with the catcher, generating radial forces that push the anvil against the guide wall, thereby increasing friction and preventing rebound without requiring high-precision guidance
Solution Approach 2:
The catcher is designed with a conical inner surface instead of a flat surface. This curved geometry, combined with the asymmetrical end face of the anvil, ensures that contact occurs at offset points, creating the tilting moment that increases frictional engagement with the guide
2Productivity
If the anvil is allowed to rebound freely to ensure complete energy transfer, then productivity is improved, but idle strikes cause unnecessary load and inefficiency
Solution Approach 1:
The catcher is positioned and dimensioned to intercept the anvil during idle strikes before it can rebound back to the working position. The conical geometry and asymmetrical contact create a stopping effect that prevents the anvil from reactivating the striking mechanism, thereby eliminating idle strikes and their associated energy waste
Solution Approach 2:
The deliberate asymmetry between the anvil's end face and the catcher surface ensures that idle strikes produce a tilting motion rather than a simple rebound. This tilting increases frictional engagement and reliably prevents the anvil from returning to the working position, ensuring complete energy dissipation
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
This design significantly reduces idle strikes, increasing the stopping effect on the anvil and maintaining efficiency even with wear, thereby improving the tool's accuracy and energy transfer to the work surface.
Implementation Method 1
The striker is coupled to the movement of the exciter piston via a pneumatic chamber
Implementation Method 2
The end face rests against the conical inner surface when the anvil is in its forwardmost position in the striking direction. The tilting leads to jamming of the anvil in the guide tube.
Implementation Method 3
The idle strike catcher for the anvil has a conical inner surface facing the anvil. The end face rests against the conical inner surface when the anvil is in its forwardmost position
Data Source
AI summary
The portable power chiseling tool has a tool holder, an electric motor, a striking mechanism and an idle strike catcher. The tool holder can receive a tool and retain it movably on a working axis. The striking mechanism includes an exciter piston, a striker, an anvil and a guide for the anvil. The exciter piston is coupled to the electric motor. The guide guides the anvil on the working axis. The idle strike catcher for the anvil has a conical inner surface facing the anvil. The anvil has an associated end face facing in the striking direction. The end face rests against the conical inner surface when the anvil is in its forwardmost position in the striking direction. The end face of the anvil has a first segment and a second segment in the circumferential direction. The second segment is offset in the striking direction relative to the first segment.