Power Tool Battery Pack Attachment Mechanism
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Solution Overview
Problem
Conventional power tools face difficulties in easily attaching and detaching battery packs in limited spaces, often resulting in damage to components, improper attachments, and potential short-circuiting due to excessive force or incorrect voltage usage.
Innovation Solution
A power tool design featuring a battery pack with engaging portions that include insertion restricting and attachment securing mechanisms, allowing for one-touch attachment and secure coupling to the power tool main body, reducing the required movement distance and preventing damage during detachment, while ensuring proper voltage matching and preventing short-circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If slide rails and guide rails are used for battery pack attachment, then the battery pack can be securely attached to the power tool main body, but the attachment and detachment require a relatively large movement distance making it difficult to perform in limited space
Solution Approach 1:
The engaging portion is divided into multiple functional segments: insertion restricting portion (guides initial insertion), attachment securing portion (provides final secure engagement), and hook engaging portion (prevents detachment). This segmentation allows each part to perform its function over a short distance, eliminating the need for long slide rail movements while ensuring secure attachment.
Solution Approach 2:
Instead of using guide rails that require the battery pack to slide a long distance into position, the invention inverts the approach by using engagement protrusions and recesses that automatically engage when the battery pack is pressed against the main body. The insertion restricting portion guides the inverted L-shaped engaging portion into the engaged portion, and the hook engaging portion then secures it, all within a minimal movement distance.
2Ease of operation
If excessive separation force is applied during battery pack detachment, then the battery pack can be removed from the power tool main body, but other members may get damaged by contact with the battery pack
Solution Approach 1:
The hook engaging portion acts as a protective mechanism that engages beforehand to secure the battery pack. During detachment, when excessive force is applied, the hook engaging portion absorbs the impact and prevents direct transmission of force to other components like the insertion restricting portion and terminal connections, thereby cushioning against potential damage.
Solution Approach 2:
The insertion restricting portion and attachment securing portion perform preliminary engagement actions that properly position and secure the battery pack before detachment occurs. This preliminary securing ensures that during normal operation, components are protected, and during detachment, the structured engagement paths guide the separation to minimize harmful contacts.
3Ease of operation
If the battery pack attachment structure is simplified, then the attachment and detachment can be performed easily, but improper attachment or voltage mismatch may occur
Solution Approach 1:
The engaging portion uses an inverted L-shaped structure with asymmetric geometry that must match the corresponding engaged portion on the power tool main body. This asymmetric design ensures that the battery pack can only be attached in the correct orientation and position, preventing improper attachment or voltage mismatch while still allowing easy one-handed operation.
Solution Approach 2:
Different portions of the engaging structure have specialized local qualities: the insertion restricting portion has a specific shape for guiding insertion, the attachment securing portion provides secure engagement, and the hook engaging portion prevents detachment. These localized functional qualities ensure proper attachment is achieved automatically through the structure's geometry, maintaining reliability while simplifying operation.
4Productivity
If the battery pack terminals are exposed, then electrical connection can be established, but terminals or connector signal lines may become short-circuited when the battery pack is not in use
Solution Approach 1:
The terminal structure uses a nested design where the terminal is housed within the battery pack case and only becomes exposed when the battery pack is properly attached to the power tool main body. The engaged portion of the main body provides a receiving structure that protects the terminal during attachment. When detached, the terminal remains retracted and protected, preventing short-circuits while ensuring efficient electrical connection during use.
Data Source
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AI summary
A power tool includes a power tool main body (1) and a battery pack (2) detachably attached to the power tool main body, the battery pack having at least two engaging portions (4,4',4'') to be mechanically coupled to the power tool main body and the power tool main body having engaged portions (5,5',5'') respectively corresponding to the engaging portions of the battery pack respectively. Each of the engaging portions of the battery pack includes an insertion restricting portion (4a,4a',4a'') and an attachment securing portion (4b,4b',4b'') for allowing its corresponding engaged portion to be inserted only in a direction of pressing the attaching portion of the battery pack against the attached portion of the power tool main body, each of the attachment securing portions being coupled to its corresponding engaged portion. At least one of said at least two engaging portions further has a hook engaging portion (12a) which is selectively secured with an engaged portion moved from its corresponding insertion restricting portion to its corresponding attachment securing portion.