Power Impact Tool Grip Positioning for Weight Balance

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Solution Overview

Problem

Existing power impact tools with heavy battery packs face rigidity issues and weight balance problems when a reinforcing connecting portion is required, leading to increased length and reduced maneuverability.

Innovation Solution

A power impact tool design with a reinforcing connecting portion that allows for manipulation of the clutch handle and trigger switch while maintaining weight balance, by positioning the grip portion between the front and rear end of the housing and integrating the battery pack at the base of the grip, ensuring space for hand operation without elongating the tool.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the grip portion is positioned at the rear end of the housing to ensure hand grip space, then the space for hand operation is sufficient, but the weight balance is lost and the tool becomes difficult to maneuver

Engineering Contradiction:
Improvespace for hand gripVSAvoidtool length
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The grip portion is repositioned from the rear end to an intermediate position on the housing, utilizing the lateral dimension rather than extending the longitudinal dimension. This allows sufficient hand grip space while maintaining a compact overall length by redistributing space in a different spatial dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If a reinforcing connecting portion is added to connect the housing with the grip portion to ensure rigidity, then the structural rigidity is improved, but the tool length increases and maneuverability decreases

Engineering Contradiction:
Improvestructural rigidityVSAvoidtool length
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The reinforcing connecting portion is integrated within the existing housing structure rather than being added as an external extension. The connecting portion is positioned to utilize the internal space of the housing, nesting the reinforcement within the existing form factor, thereby providing structural rigidity without increasing the external dimensions of the tool.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If the clutch handle is positioned at the front end of the housing for easy access, then the ease of operation is improved, but the reinforcing connecting portion cannot be properly positioned without interfering with clutch handle manipulation

Engineering Contradiction:
Improveclutch handle accessibilityVSAvoidspatial arrangement complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The clutch handle is positioned asymmetrically at the front end of the housing, while the reinforcing connecting portion is positioned asymmetrically at the rear end. This asymmetric distribution allows both components to coexist without interference, with the clutch handle maintaining front accessibility and the connecting portion providing rear structural support.

Inventive Principle:
Principle #4Asymmetry

4Ease of operation

If the grip portion is positioned at the rear end of the housing, then two hands are required to grip both portions, but if positioned at the front, the weight balance is lost

Engineering Contradiction:
Improvehand grip configurationVSAvoidweight balance
Core Design Contradiction:
Ease of operationVSWeight of moving object

Solution Approach 1:

The grip portion is positioned at an intermediate location on the housing to serve as a counterbalance point. This intermediate positioning creates a balanced weight distribution where the grip portion acts as a fulcrum, allowing the heavy battery pack at the rear and the motor at the front to be balanced around the grip location, enabling comfortable one-handed operation.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Data Source

PatentEP1795311B1Power impact tool
Publication Date: 2011.09.21 PANASONIC ELECTRIC WORKS CO LTD
  • EP1795311B1 patent drawingFigure 1
  • EP1795311B1 patent drawingFigure 2
  • EP1795311B1 patent drawingFigure 3

AI summary

A power impact tool includes a main body accommodating a chuck at a front end portion thereof; a clutch handle (48) for setting a torque applied to the chuck; a grip (90) including a base portion; a free end portion; and a reinforcing connecting portion (92) connected to the front end portion of the main body (90) at the back of the clutch handle (48) and to the free end portion of the grip (90). The reinforcing connecting portion (92) is disposed in front of the grip (90); and a part protruded most forward among the reinforcing connecting portion (92) is located directly in front of the trigger switch (93) disposed at the base portion of the grip. A part of the reinforcing connecting portion (92) disposed behind the clutch handle (48) retreats backward toward the free end portion of the grip.