Battery-Loaded Tool Handle Geometry for Easier Grasping
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Solution Overview
Problem
The existing handle configuration of hand-held battery type electric tools, where battery cells are arranged in a triangular fashion with the apexes on the front and a flat surface on the rear, makes it difficult for users to grasp and apply force, impairing the tool's workability.
Innovation Solution
Reversing the handle configuration so that the apex portion with large curvature is on the front and the base portion with smaller curvature is on the rear, allowing fingertips to contact the apex and the palm to contact the base, enhancing the grasping feel and usability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If battery cells are arranged in a triangular fashion with apexes on the front surface side, then the handle configuration is compact and space-efficient, but the grasping feel deteriorates and operability worsens
Solution Approach 1:
The patent inverts the conventional triangular arrangement by placing the base of the triangle on the front surface side and the apex on the rear surface side, rather than the conventional apex-forward configuration. This inversion transforms the handle geometry to provide a flat front surface for palm contact while maintaining the compact triangular battery arrangement, thereby resolving the contradiction between space efficiency and grasping comfort
Solution Approach 2:
The patent applies different surface qualities to different regions of the handle: the front surface is designed with a flat configuration for palm contact, while the rear surface maintains the triangular apex configuration. This local differentiation allows each region to serve its specific function - the flat front provides comfortable grasping while the triangular structure maintains compactness
2Ease of manufacture
If the handle portion has a flat surface configuration, then manufacturing is simplified, but the ability to apply pressing force against workpiece deteriorates
Solution Approach 1:
The patent inverts the expected configuration by making the front surface (workpiece-contact side) flat and the rear surface (hand-grasping side) triangular. This allows the flat front surface to simplify manufacturing and provide stable tool-bit alignment, while the triangular rear surface with apex contact enables effective force application by the user's palm
Data Source
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AI summary
In an electric tool of the type whose handle portion to be grasped by the user is loaded with a battery pack, the sectional configuration of the handle portion may be one making the grasping rather difficult depending upon the way a plurality of battery cells are arranged. The present invention aims to enhance the operability of an electric tool of the type which is loaded with a battery pack provided with three battery cells by adopting a sectional configuration for the handle portion which enables the handle portion to be grasped easily. Three battery cells (21, 22, 23) are arranged such that one battery cell (23) is situated on the front side of a handle portion (10) and that the remaining two battery cells (21, 22) are situated on the rear side thereof while being arranged laterally side by side; the handle portion (10) is generally of a triangular cross-sectional configuration whose apex portion (11a) is situated on the front side of the handle portion (10) and whose base portion (11b) is situated on the rear side thereof; and the handle portion is grasped by bringing fingertips (Hf) into contact with the apex portion (11a) on the front side.