Ergonomic Handgrip Design for Power Tool Fatigue Reduction
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Solution Overview
Problem
Hand-held power tools cause user fatigue and pain due to concentrated load distribution during operation, particularly when using the second holding pattern where the rear end of the body housing is pressed forward toward the tool bit.
Innovation Solution
The design incorporates a handgrip with a first circular arc portion and a holding part with a second circular arc portion, where the radius of the second circular arc portion is larger than the first, allowing for a more even load distribution and alleviating user fatigue and pain by spreading the load over a wider area when holding the tool with the first and second fingers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the rear end of the body housing is pressed forward toward the tool bit during operation, then the power tool can be held in a second holding pattern with first and second fingers, but the load becomes concentrated on the web part between fingers causing user fatigue and pain
Solution Approach 1:
The patent applies local quality by providing different circular arc portions at different locations of the power tool. The handgrip has a first circular arc portion with a specific radius, while the holding part has a second circular arc portion with a larger radius. This local differentiation allows the tool to adapt to different holding patterns and distribute load appropriately for each holding position, resolving the contradiction between ease of operation and user comfort.
Solution Approach 2:
The patent utilizes curvature by incorporating circular arc portions with specific radii at the handgrip and holding part. The first circular arc portion has a radius R1, and the second circular arc portion has a larger radius R2. These curved surfaces conform to the natural shape of user fingers and web parts, enabling comfortable contact and even load distribution in both first and second holding patterns, thereby eliminating user fatigue and pain.
2Device complexity
If a standard handgrip design is used, then the power tool structure is simple, but the load distribution on user fingers is uneven causing fatigue
Solution Approach 1:
The patent implements local quality by adding circular arc portions with specific radii to the handgrip and holding part. The first circular arc portion at the handgrip has radius R1, and the second circular arc portion at the holding part has radius R2 where R2 > R1. This localized structural modification creates different contact surfaces that distribute load evenly across user fingers in both holding patterns, improving ease of operation without significantly increasing overall device complexity.
Solution Approach 2:
The patent applies parameter changes by specifying different radius parameters for the circular arc portions. The first circular arc portion has radius R1 and the second has radius R2, with R2 being larger than R1. By changing these geometric parameters, the patent optimizes load distribution characteristics for different holding patterns, transforming a standard handgrip design into an ergonomic structure that reduces user fatigue.
Data Source
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AI summary
It is an object of the invention to provide a fatigue reducing structure in a hand-held power tool. A representative screwdriver 100 includes a body 101, an anvil 106, a driver bit 110, a driving motor 120, a handgrip 130, a trigger 131, a rear end groove 109 pressed forward toward the driver bit 110, while being held with first and second fingers of user's hand on a housing rear end 101 a side of the body 101, a circular arc portion 130c having a horizontal section of a circular arc shape on a rear end of the handgrip 130 and a middle portion 109b having a horizontal section of a circular arc shape on a housing rear end 101 a side of the holding part, which circular arc shape has a curvature larger than that of the circular arc shape of the first circular arc portion.