Handheld Power Tool Ergonomic Abutment Surface Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric screwdrivers often require high contact pressure for applications like fastening sheet metal, which existing designs fail to provide effectively, leading to user discomfort and potential tool slippage during prolonged use.
Innovation Solution
A hand-held electric screwdriver design featuring a housing with a thumb and index finger rest portion in a plane and an inclined abutment surface for additional contact pressure, preventing slippage and perceived as more ergonomic, allowing users to apply higher forces without hand span discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a pistol grip design is used for compact and lightweight applications, then the tool is suitable for low contact pressure tasks, but it cannot provide sufficient contact pressure for high-force applications like fastening sheet metal
Solution Approach 1:
The patent introduces a second hand gripping portion with an abutment surface that is offset from the tool holder axis and inclined at 80-100 degrees, creating a new dimensional arrangement for force application. This allows the second hand to apply contact pressure in a different spatial orientation, enabling high-force applications while maintaining ergonomic comfort through proper hand positioning.
2Force
If the abutment surface is positioned close to the tool holder, then the structure remains compact, but the second hand cannot effectively apply additional contact pressure
Solution Approach 1:
The patent specifies that the abutment surface should be located at a distance of 3-10 cm from the tool holder along the axis, and inclined at 80-100 degrees from the plane containing the thumb and index finger rest portion. These parameter changes optimize the leverage and force application geometry, allowing the second hand to effectively apply contact pressure while maintaining a compact overall structure.
3Reliability
If the abutment surface is parallel to the plane with the axis, then the design is simple, but the hand slips off the device during use
Solution Approach 1:
The patent specifies that the abutment surface should be inclined at 80-100 degrees from the plane containing the thumb and index finger rest portion. This angular parameter change creates optimal friction and normal force components that prevent the hand from slipping off the device while maintaining structural simplicity.
4Force
If a detachable auxiliary handle is used for high contact pressure applications, then additional force can be applied, but the tool requires two hands and loses compactness
Solution Approach 1:
The patent merges the function of the auxiliary handle into the main housing by integrating the second hand gripping portion directly into the housing structure. This allows the user to apply high contact pressure using the second hand on the abutment surface while maintaining a unified, compact tool design that can still be operated with one hand when needed.
Data Source
Figure 1~2
AI summary
The hand machine tool (10) has a tool holder (14) for holding a tool (18) along a working axis (17), and a housing (11). A grip area is provided for a hand, where the grip area has a support section for thumb and forefinger in a guide plane with the working axis. The grip area has a shaft section for encompassing on a side of the guide plane. A bearing surface is provided for another hand.