Power Tool Depth Adjustment via Pinion and Indexing

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Solution Overview

Problem

Existing fastening tools lack flexibility in adjusting the penetration depth of fasteners, limiting user control and functionality.

Innovation Solution

A fastening tool with a depth adjusting assembly that includes a knob with indexing formations, a pinion gear, and an indexing member, allowing for precise control of fastener depth through rotational motion and axial translation, along with a lock-out mechanism to prevent accidental actuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a depth adjusting assembly with multiple components (knob, pinion, indexing member) is added to enable precise depth control, then the manufacturing precision and adaptability are improved, but the device complexity increases

Engineering Contradiction:
Improvefastener penetration depth controlVSAvoiddepth adjusting assembly structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The depth adjusting assembly is divided into distinct functional components: a knob for user input, a pinion gear for rotational-to-linear conversion, and an indexing member with locating formations for precise positioning. Each component performs a specific function, allowing modular design and easier manufacturing while achieving precise depth control through their coordinated interaction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pinion gear acts as an intermediary mechanism between the knob's rotational motion and the linear depth adjustment requirement. It converts the rotational input from the knob into precise linear displacement of the fastener penetration depth, enabling accurate control without direct mechanical linkage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If an indexing member with locating formations is implemented to maintain specific depth settings, then the measurement precision and reliability are improved, but the device complexity increases

Engineering Contradiction:
Improvedepth setting accuracyVSAvoidindexing mechanism structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The indexing member includes pre-formed locating formations (such as detents or indexing positions) that are prepared in advance to engage with corresponding features on the knob. This preliminary configuration enables automatic positioning and maintenance of specific depth settings without requiring additional active components or complex control systems during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The indexing mechanism is designed to self-position and self-maintain the selected depth setting through the interaction between the indexing member's locating formations and the knob's corresponding features. Once engaged, the system automatically holds the position without requiring external intervention or additional power sources.

Inventive Principle:
Principle #25Self-service

3Reliability

If a lock-out mechanism is added to prevent accidental actuation, then the reliability and safety are improved, but the device complexity increases

Engineering Contradiction:
Improveprevention of accidental activationVSAvoidlock-out mechanism structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lock-out mechanism incorporates a lock-out member that is positioned to preemptively prevent accidental actuation of the depth adjusting mechanism. This preliminary protective action blocks unintended movement before it can occur, ensuring reliability and safety while using a simple mechanical configuration that does not significantly increase overall device complexity.

Inventive Principle:
Principle #9Preliminary anti-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

Enables users to set and maintain specific fastener depths accurately, enhancing user control and safety by preventing unintended activation.

Implementation Method 1

The indexing member can translate in a direction parallel to an axis of rotation of the knob

Methodology Applied
Scientific EffectMechanical Translation:

Implementation Method 2

A pinion gear can be rotatably engaged with the knob and adapted to convert rotational motion of the knob to linear motion of an adjustment rod

Methodology Applied
Scientific EffectGear Mechanism: Gear

Implementation Method 3

The pinion can define pinion threads formed within an inner diameter and the adjustment rod can define rod threads formed on an outer diameter, with the pinion and adjustment rod in threaded engagement

Methodology Applied
Scientific EffectScrew Mechanism: Screw

Data Source

PatentEP1916067B1Depth adjusting device for a power tool
Publication Date: 2011.08.31 BLACK & DECKER CORP
  • EP1916067B1 patent drawingFigure 1
  • EP1916067B1 patent drawingFigure 2
  • EP1916067B1 patent drawingFigure 3

AI summary

A fastening tool (10) includes a housing (12) and a motor assembly in the housing. The motor assembly includes an output member (18) and a motor (14) for translating the output member. A knob (74) is rotatably coupled to the housing and includes a first surface. An adjustment element (86) has a second surface and a threaded aperture. The second surface is engaged to the first surface such that rotation of the knob effects corresponding rotation of the adjustment element. An adjustment rod (62) is threadably received into the threaded aperture. A lower contact trip (50) is coupled to the adjustment rod (62). A locating formation (130) is coupled to one of the housing and the knob. An indexing member (100) is coupled to the other of the housing and the knob. The indexing member (100) engages the locating formation (130) to resist rotation of the knob (74) relative to the housing (12).