Utility Knife Clamp Assembly and Blade Wiper Mechanism

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Solution Overview

Problem

Existing utility knives lack an efficient mechanism for securely holding and easily replacing blades, as well as effectively managing debris on the blade surfaces, which can lead to jamming and reduced performance.

Innovation Solution

A utility knife design featuring a clamp assembly with a manually actuatable actuator portion and support portion that applies clamp force to the blade holder assembly, along with a resilient blade wiper to remove debris from the blade surfaces before retraction, ensuring secure blade retention and preventing jamming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a clamp assembly is added to secure the blade, then blade retention is improved, but device complexity increases

Engineering Contradiction:
Improveblade retentionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The clamp assembly integrates the actuator portion, support portion, and clamp force application mechanism into a single unified structure that combines multiple functions (blade clamping, actuation, and force application) into one component system, reducing overall device complexity while maintaining secure blade retention

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cam surface portions automatically generate clamp force through their geometric shape when the actuator is moved, eliminating the need for additional springs or complex forcing mechanisms - the geometry itself provides the mechanical advantage needed to secure the blade

Inventive Principle:
Principle #25Self-service

2Reliability

If a blade wiper is added to remove debris, then blade performance is improved, but device complexity increases

Engineering Contradiction:
Improveblade performanceVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blade wiper is integrated with the handle structure, combining the debris removal function with the existing handle geometry rather than adding a separate, independent wiper mechanism, thus minimizing increase in device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The resilient blade wiper uses its own elasticity to contact and wipe the blade surface during blade retraction or extension movements - the blade's own motion drives the cleaning action without requiring separate actuation mechanisms

Inventive Principle:
Principle #25Self-service

3Ease of operation

If manual actuation mechanism is added, then blade replacement ease is improved, but device complexity increases

Engineering Contradiction:
Improveblade replacement easeVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The manual actuator replaces complex multi-component mechanical fastening systems with a simpler cam-based actuation mechanism that uses geometric shape change rather than threaded fasteners or clips, reducing the number of parts while improving ease of operation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The cam surface portions change their geometric parameters (position and orientation) as the actuator moves, transforming the actuator's linear or rotational motion into the lateral pressure needed to wedge and secure the blade, providing intuitive manual control

Inventive Principle:
Principle #35Parameter changes

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 solution provides secure blade retention and prevents debris from entering the handle, maintaining the knife's functionality and extending blade life by ensuring clean blade storage.

Implementation Method 1

cam surface portions of the first handle portion are constructed and arranged to engage with cam surface portions of the support portion, wherein the relative movement of the cam surface portions forces the clamp assembly to apply clamp force

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

a resilient blade wiper to remove debris from the blade surfaces before retraction

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2153949B1Utility knife
Publication Date: 2017.01.11 STANLEY BLACK & DECKER INC
  • EP2153949B1 patent drawingFigure 1
  • EP2153949B1 patent drawingFigure 2
  • EP2153949B1 patent drawingFigure 3

AI summary

A utility knife (10) includes a handle (12), a blade holder assembly (14), and a clamp assembly (22). The blade holder assembly is constructed and arranged to hold a blade (30) at a position of use at one end of the handle. The clamp assembly is constructed and arranged to move between a clamp position wherein the clamp assembly applies a clamp force to side surfaces (36) the blade and a release position wherein the clamp assembly releases the clamping force.