Hand Tool Attachment With Reach-Through Opening For Torque Adjustment

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Solution Overview

Problem

Existing hand-held power tool attachments are not easy or convenient to handle, particularly in terms of accessing and adjusting operating elements like torque settings and coupling devices.

Innovation Solution

The attachment features a conical housing with a reach-through opening allowing operators to grip a handle element, enabling access to internal operating elements such as torque adjustment handles or coupling device handles, which can be rotated and adjusted through the opening, ensuring secure operation and ergonomic design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the attachment device uses a compact housing design, then the device complexity is reduced, but the accessibility to operating elements inside the attachment becomes difficult

Engineering Contradiction:
Improveaccessibility to operating elementsVSAvoidhousing structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The housing is divided into a base housing and a separately detachable support surface, allowing the support surface to be removed for access to operating elements while maintaining a compact overall structure. This segmentation enables easy access to internal components without requiring a completely open housing design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support surface is arranged in a plane that is offset from the base housing, creating a spatial separation that allows operating elements to be accessed from a different dimension. This dimensional arrangement provides access pathways without increasing the footprint of the attachment device.

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

2Ease of operation

If the handle is made rotaryally coupled to the input shaft, then the ergonomic design is improved, but the safety during operation is reduced due to rotation while running

Engineering Contradiction:
Improveergonomic designVSAvoidsafety during operation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Instead of coupling the handle rotaryally to the input shaft, the invention inverts the approach by making the handle fixed relative to the housing while allowing the input shaft to rotate. This inversion eliminates the risk of the handle rotating during operation while still providing ergonomic grip through the offset arrangement of the support surface and handle.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The support surface acts as an intermediary element that transfers the rotational motion of the input shaft to the handle through a friction connection. This intermediary mechanism allows the handle to remain stationary and safe while still enabling power transmission to the attached tool.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the support surface is detachable from the base housing, then the ease of assembly and disassembly is improved, but the structural stability of the attachment is reduced

Engineering Contradiction:
Improveease of assembly and disassemblyVSAvoidstructural stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The connection between the support surface and base housing is designed to be dynamically changeable, allowing easy detachment for assembly and disassembly of the attachment, while maintaining stable connection during operation through the friction-based coupling mechanism that prevents unintended separation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The support surface is pre-configured with connection elements that align with corresponding elements in the base housing, enabling quick and accurate assembly without complex alignment procedures. This preliminary arrangement of connection features facilitates easy attachment while ensuring stable structural connection when assembled.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design enhances the ease of handling and safety by allowing secure grip and adjustment of handles during operation, reducing the risk of injury and facilitating easy attachment and removal of the tool, while maintaining an ergonomic and cost-effective modular concept.

Implementation Method 1

The handle is slidably mounted parallel to a rotational axis of the input shaft or machine output and is frictionally connected to the input shaft or machine output with respect to rotation

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2383076B1Auxiliary device for a hand machine tool and hand machine tool with same
Publication Date: 2019.07.24 FESTOOL GMBH
  • EP2383076B1 patent drawingFigure 1~4
  • EP2383076B1 patent drawingFigure 5
  • EP2383076B1 patent drawingFigure 6~7

AI summary

The attachment (30) has a housing (35) between a drive part and a through opening (60) for manual penetration into a housing interior. The through opening is provided for manually actuating a handle (27,58) arranged in the housing interior. The handle is arranged to an actuating element for adjusting a gear unit or a torque limiting device (28).