Multi-bit Tool Rigid Frame Prevents Actuator Jamming

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Solution Overview

Problem

Multi-bit screwdrivers with spring-loaded actuation mechanisms often jam due to torsional deformation and movement of cartridges, requiring users to manually retract one bit before extending another, leading to user fatigue and ergonomic issues.

Innovation Solution

A multi-bit tool with a substantially rigid main frame member that prevents torsional deformation, housing spring-loaded actuator mechanisms in rigidly retained channels to maintain their form and prevent jamming, and an annular collar member for ergonomic operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If cartridge type spring loaded actuation mechanisms are closely fit into the housing in abutting relation, then the device compactness is improved, but the reliability deteriorates due to frequent jamming of working elements

Engineering Contradiction:
Improvedevice compactnessVSAvoidjamming frequency
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The housing is divided into separate segments or sections, each containing individual actuation mechanisms. This segmentation allows each mechanism to operate independently with its own clearances, preventing jamming while maintaining overall compactness through the integrated modular structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the housing are designed with different clearance specifications. Critical areas near actuation mechanisms have larger local clearances to prevent jamming, while non-critical areas maintain tight tolerances for compactness. This localized quality adjustment resolves the contradiction between compactness and reliability.

Inventive Principle:
Principle #3Local quality

2Strength

If the housing is designed to transmit significant torque, then the strength is improved, but the stability deteriorates due to torsional deformation causing cartridge misalignment

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidcartridge alignment
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The housing is pre-reinforced with stiffening ribs, gussets, or internal support structures in areas susceptible to torsional deformation. This preliminary structural reinforcement prevents deformation before it occurs during torque transmission, maintaining cartridge alignment while enabling high torque capacity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The housing is constructed using composite material structures combining different materials or hybrid constructions (e.g., metal reinforcement inserts in polymer housing, or multi-layer composite walls) that provide both high torque transmission capability and resistance to torsional deformation, thus maintaining cartridge alignment stability.

Inventive Principle:
Principle #40Composite materials

3Ease of operation

If a collar type selector mechanism is used to improve ergonomics, then the ease of operation is improved, but the reliability deteriorates due to housing deformation causing mechanism sticking

Engineering Contradiction:
Improveergonomic performanceVSAvoidmechanism sticking frequency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A rigid intermediary frame or support structure is introduced between the collar selector mechanism and the housing. This intermediary element isolates the selector mechanism from housing deformations caused by torque transmission, preventing sticking while maintaining the ergonomic benefits of the collar design.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Significantly reduces jamming of tool bit assemblies and actuation mechanisms, enhancing ergonomic design and ease of use by maintaining a straight path for bit assemblies and reducing friction.

Implementation Method 1

spring loaded actuator mechanisms

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP2519386B1Multi-bit tool having spring loaded actuation mechanisms and a rigid structural frame
Publication Date: 2017.07.19 GRAND GERARD
  • EP2519386B1 patent drawingFigure 1
  • EP2519386B1 patent drawingFigure 2
  • EP2519386B1 patent drawingFigure 3

AI summary

A multi-bit tool comprises a housing having a bit chuck with a bit-receiving opening. A substantially rigid main frame member defines a plurality of longitudinal channels and is disposed within the housing such that each of the plurality of longitudinal channels is generally aligned along the longitudinal axis of the multi-bit tool. A plurality of spring loaded actuator mechanisms are mounted in rigidly retained relation within one channel of the frame member. Each spring loaded actuator mechanism has a carriage member movable between a rearward position and a forward position, and a trigger member movable between a rest position, a forward triggering position and a rearward triggering position. The carriage member is moved to its rearward position by movement of the trigger member to its rearward triggering position and the carriage member is moved to its forward position by movement of the trigger member to its forward triggering position. Bit assemblies having a tool bit arc operatively mounted within the housing for movement by the actuator mechanism between a retracted con figuration and a forwardly extended in-use configuration corresponding. Each bit assembly is operatively connected to the carriage member on a corresponding spring loaded mechanism for co-operative movement therewith.