Tool-Free Depth-of-Drive Adjustment Mechanism

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Solution Overview

Problem

Existing fastener-driving tools face challenges in maintaining depth-of-drive adjustment without tools, requiring users to exert excessive energy and deal with loosening issues during operation, and often necessitate replacing the entire tool when the workpiece contact element expires.

Innovation Solution

A tool-free depth-of-drive adjustment assembly that uses a biased stop mechanism with toothed surfaces and camming elements, allowing for easy adjustment and locking without tools, and can be easily replaced when the workpiece contact element needs updating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional threaded fastener system is used for depth adjustment, then the adjustment can be secured, but users require tools (Allen wrench, nut driver) and excessive energy to loosen and retighten fasteners during operation

Engineering Contradiction:
Improveease of adjustmentVSAvoidcomplexity of adjustment mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the conventional threaded fastener system with a camming mechanism. The camming element converts rotational motion into linear motion to adjust the stop position, eliminating the need for threaded fasteners and tools. This substitution reduces the operational complexity while maintaining secure adjustment capability.

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

Solution Approach 2:

The adjustment mechanism is designed to be self-servicing through the camming system. The camming element allows users to easily loosen and retighten the adjustment without requiring external tools, enabling quick modifications during operation. The spring-loaded design automatically maintains engagement pressure.

Inventive Principle:
Principle #25Self-service

2Reliability

If threaded fasteners are used to secure the adjustment, then the position can be maintained, but the fasteners loosen and vary during operation due to extreme shock forces

Engineering Contradiction:
Improvestability of adjustmentVSAvoidease of adjustment
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces threaded fasteners with a camming mechanism that uses geometric locking instead of friction-based threading. The camming element's inclined surface creates a mechanical lock that resists shock forces more effectively, preventing loosening during operation while maintaining easy adjustability.

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

Solution Approach 2:

The camming element utilizes curved surfaces to create the locking mechanism. The cam profile converts rotational input into linear positioning with inherent mechanical advantage, providing stable positioning that resists shock forces without requiring tight threaded fasteners.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Device complexity

If the workpiece contact element is integrated into the tool, then the tool structure is simplified, but the entire tool must be replaced when the contact element expires

Engineering Contradiction:
Improvesimplicity of tool structureVSAvoidease of replacement
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The patent divides the tool into separable modules: the workpiece contact element and the main tool body. The depth adjustment assembly is designed as a removable unit that can be independently replaced when worn, eliminating the need to replace the entire tool. This segmentation maintains structural simplicity while enabling easy maintenance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design allows the workpiece contact element and adjustment assembly to be discarded and replaced as wear occurs, while the main tool body is retained and reused. This extends the overall tool life and reduces waste by recovering the durable main body while replacing only the consumable components.

Inventive Principle:
Principle #34Discarding and recovering

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

Enables secure, tool-free adjustment and maintenance of depth-of-drive with reduced user effort, allowing for easy replacement of the workpiece contact element without replacing the entire tool, thus improving operational efficiency and extending tool life.

Implementation Method 1

a camming element (54) carried on each tab (48)... movement of the camming element (54) in a first direction along the inclined surface (45) causes the stop (24) to move from the locked position to the adjusting position

Methodology Applied
Scientific EffectCamming mechanism: Cam

Implementation Method 2

a spring (26) configured for exerting a biasing force against the stop (24)... urging the stop into engagement with the workpiece contact element (18) in the locked position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

The gripping surfaces (68) are configured for providing an enhanced grip on the camming element (54) for manual manipulation of the stop (24) between the locked position and the adjusting position

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2734336B1Easy grip tool-free depth-of-drive adjustment
Publication Date: 2020.12.30 ILLINOIS TOOL WORKS INC
  • EP2734336B1 patent drawingFigure 1
  • EP2734336B1 patent drawingFigure 2
  • EP2734336B1 patent drawingFigure 3

AI summary

An adjustable depth-of-drive assembly for use with a fastener-driving tool upper probe includes a workpiece contact element carried on the upper probe and having a contact end and an adjustment end, a stop configured for being secured to the upper probe and being moveable between an adjusting position in which the workpiece contact element is movable relative to the upper probe, and a locked position wherein the adjustment end is secured against movement relative to the upper probe, a biasing element associated with the stop and configured for urging the stop and the adjustment end into a selected locked position relative to the upper probe with a biasing force, and at least one camming element carried on the stop for selective camming engagement between the upper probe and the stop by means of a user's manual force to urge the stop into the adjusting position against the biasing element force.