Power Tool Position Feedback for Accurate Screw Depth Control

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Solution Overview

Problem

Conventional power tools, such as drills and drivers, require precise manual throttling to achieve the correct screw depth, which is challenging due to the quick nature of the driving process, often resulting in overdriving or underdriving, leading to damage or the need for repetitive processes.

Innovation Solution

A power tool equipped with position feedback control using sensors and a controller that determines operating angles and drive depth, allowing for automatic adjustment and mode selection to ensure accurate screw driving, including blind hole and auto flush modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual throttling is used to control screw depth, then the user can operate the tool, but the screw depth precision deteriorates resulting in overdriving or underdriving

Engineering Contradiction:

Improvemanual throttling operationVSAvoidscrew depth control

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements a feedback control system using position sensors (e.g., optical encoders) to continuously monitor the rotational position of the motor shaft and the linear position of the drive mechanism. This feedback is fed to a controller that automatically adjusts the motor power to stop the driving operation precisely when the screw reaches the flush position, eliminating the need for manual throttling while maintaining high depth precision.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces the manual mechanical throttling system with an automated electronic control system. The controller uses feedback from position sensors to electronically regulate motor power, substituting the imprecise mechanical trigger release mechanism with a precise electronic feedback loop that automatically controls screw depth.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If the driving process is restarted after underdriving, then the screw can be driven to correct depth, but the risk of damage increases due to slippage or stripping

Engineering Contradiction:

Improvescrew depth accuracyVSAvoiddamage to screw or workpiece

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent performs preliminary action by pre-calculating and pre-positioning the drive mechanism to achieve the exact flush depth in a single continuous driving operation. The feedback control system monitors position throughout the process and ensures the screw is driven to the correct depth without stopping or restarting, thereby preventing cam-out, slippage, and damage that would occur with repeated attempts.

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If position feedback control is implemented, then screw depth precision is improved, but device complexity increases due to additional sensors and controllers

Engineering Contradiction:

Improvescrew depth controlVSAvoidcontrol system structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements a multi-functional integrated control system where the controller performs multiple functions: it processes feedback from position sensors, regulates motor power delivery, determines when to stop the driving operation, and can adapt to different screw types and materials. This universal controller consolidates what would otherwise require multiple separate components, managing the complexity through functional integration.

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 power tool ensures precise screw depth control, reducing the risk of damage and eliminating the need for repetitive processes by automatically adjusting based on detected positions and angles, enhancing user control and tool performance.

Implementation Method 1

A power tool equipped with position feedback control using sensors and a controller that determines operating angles and drive depth

Methodology Applied

Scientific EffectPosition feedback detection:

Data Source

PatentUS11752586B2Position feedback control method and power tool

Publication Date: 2023.09.12 TRANSFORM SR BRANDS LLC

AI summary

Various embodiments of power tool and method of operating same are described. The power tool may include a first position sensor, a second position sensor, a third position sensor, and a controller. The first, second, and third position sensors may each generate a signal indicative of a distance between the respective position sensor and a workpiece. The controller may determine one or more angles of the power tool with respect to the workpiece based on the first, second, and third signal and present an indication as to whether the one or more angles are within a predetermined range. The controller may further obtain a depth measurement based on the first signal, the second signal, and the third signal and generate, based on the obtained depth measurement, one or more control signals that control operation of the power tool.