Rotatable Lockable Cable Sheath for Power Tool

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Solution Overview

Problem

Existing power tool designs with protective cable sheaths often become misaligned due to unintentional rotational forces, requiring users to manually realign them, which can lead to misalignment issues and reduced maneuverability.

Innovation Solution

A rotatable and lockable cable sheath system with a helical spring biasing mechanism, an annular flange, and a tongue-and-groove arrangement that provides tactile feedback and directional support, allowing deliberate axial movement to unlock and rotate the sheath, ensuring proper alignment and protection against wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protective cable sheath is added to protect the electric supply cable, then cable protection against wear is improved, but maneuverability of the power tool deteriorates

Engineering Contradiction:
Improvecable protectionVSAvoidmaneuverability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cable sheath is made rotatable relative to the cable outlet, transforming from a static protective cover to a dynamic component that can rotate. This allows the sheath to adapt to different operational orientations while maintaining protection, thereby improving maneuverability without sacrificing cable protection reliability

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the cable sheath is made rotatable to improve maneuverability, then ease of operation is improved, but alignment stability deteriorates

Engineering Contradiction:
ImprovemaneuverabilityVSAvoidalignment stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The locking means is designed to automatically engage with the biasing means when the sheath rotates to specific predetermined orientations. This preliminary positioning action ensures that the sheath locks into stable, pre-determined alignment positions, maintaining alignment stability while allowing controlled rotation for maneuverability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The interaction between the locking means and biasing means provides tactile feedback to the user when the sheath reaches locked positions. This feedback mechanism confirms proper alignment and stabilizes the sheath in correct orientations, preventing unintended rotation while maintaining ease of deliberate repositioning

Inventive Principle:
Principle #23Feedback

3Stability of the object's composition

If a locking mechanism is added to prevent unintentional rotation, then alignment stability is improved, but device complexity deteriorates

Engineering Contradiction:
Improvealignment stabilityVSAvoidmechanism complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The locking means and biasing means are integrated into a unified mechanism where the biasing means both unlocks the locking means and provides the locking force simultaneously. This merging of functions reduces the number of separate components needed, thereby reducing device complexity while maintaining alignment stability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The biasing means serves multiple functions: it biases the locking means to engage, provides the locking force to prevent unintentional rotation, and enables deliberate unlocking when force is applied. This multi-functionality reduces the need for separate components, simplifying the overall mechanism while ensuring alignment stability

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The system effectively blocks unintentional rotational forces, provides positive tactile feedback, and allows easy reorientation of the sheath, enhancing user control and extending the life of the electric supply cable by preventing misalignment and wear.

Implementation Method 1

a helical spring biasing mechanism

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP2604395B1Electric supply cable sheath for a power tool
Publication Date: 2015.05.20 BLACK & DECKER CORP
  • EP2604395B1 patent drawingFigure 1
  • EP2604395B1 patent drawingFigure 2
  • EP2604395B1 patent drawingFigure 3

AI summary

A power tool comprising: a housing; a cable outlet (21a,80,100,106) with a central axis (82); an motor; a flexible electrical supply cable (42); a cable sheath (84) for protecting supply cable projected through the cable outlet and for directing unprotected supply cable away from the central axis wherein the sheath is rotatable to change direction of unprotected supply cable; and locking means for locking the sheath in one of a plurality of rotational orientations. The locking means comprises: a receiving member (104a,104b) connected to one of the sheath or the cable outlet; an engaging member (98) connected to the other of the sheath or the cable outlet; and a biasing means (108) for biasing the engaging and receiving members into engagement to lock the sheath in a rotational orientation, wherein movement of the sheath against the biasing means disengages the engaging and receiving members and unlocks the sheath for rotation.