Multi-Angled Follower Arm Activation System for Cordless Nailers

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Solution Overview

Problem

Existing fastening tools, such as cordless nailers, are often cumbersome due to size and weight, require expensive non-refillable fuel cartridges, and have complex designs that lead to inconsistent fastener driving, necessitating a more flexible and reliable solution.

Innovation Solution

A fastening tool with a multi-angled follower arm and stall release lever, featuring a solenoid-actuated roller assembly that provides non-linear displacement and self-locking mechanism for efficient energy transfer and jam release, allowing for compact design and reliable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If cordless nailers are designed to be compact and lightweight, then ease of operation improves, but reliability and consistent fastener driving deteriorate

Engineering Contradiction:
Improveease of operationVSAvoidreliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The activation arm assembly employs a dynamic multi-angled follower arm that changes its angular position during operation. The follower arm transitions from a first angle relative to the actuator axis in the retracted position to a second angle in the engaged position, allowing the mechanism to adapt its mechanical advantage throughout the stroke to maintain reliability while keeping the tool compact.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mechanism changes the geometric parameters of the follower arm configuration during operation. By varying the angle of the follower arm relative to the actuator axis as it moves from retracted to engaged position, the system optimizes force transmission at different stages of the driving cycle, ensuring consistent fastener driving in a compact design.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the activation mechanism uses a linear actuator with direct linear motion, then device complexity reduces, but energy efficiency and thermal loading worsen

Engineering Contradiction:
Improvedevice complexityVSAvoidenergy efficiency
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The follower arm introduces a curved, non-linear motion path to the otherwise linear actuator output. This curvature allows the mechanism to convert the linear actuator motion into an optimized engagement path that reduces thermal loading and improves energy efficiency while maintaining relatively simple device architecture.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Manufacturing precision

If the follower arm engages the driver with high force, then manufacturing precision improves, but the risk of jamming and incomplete drive cycles increases

Engineering Contradiction:
Improvemanufacturing precisionVSAvoidreliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The multi-angled follower arm dynamically adjusts the engagement characteristics throughout the drive cycle. The changing angle allows the mechanism to apply high force during the critical manufacturing precision phase while automatically reducing stress during the return stroke, preventing jams and incomplete cycles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mechanism includes self-service features such as the follower arm's automatic reset capability and the integrated return spring that ensures the driver returns to the retracted position. These self-service mechanisms prevent jams and incomplete drive cycles without requiring external intervention, maintaining both precision and reliability.

Inventive Principle:
Principle #25Self-service

4Reliability

If the tool uses a complex activation system with multiple components, then reliability improves, but device complexity and manufacturing cost increase

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The mechanism merges multiple functions into the single follower arm component. The follower arm simultaneously provides force transmission, positional control, and return motion guidance, consolidating what could be multiple separate components into one integrated element. This reduces device complexity while maintaining the reliability benefits of a multi-functional activation system.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances flexibility and reliability by reducing tool size and weight, conserving energy, and ensuring consistent fastener driving with a compact, efficient design that minimizes energy usage and thermal loading, while allowing for easy jam release.

Implementation Method 1

an actuator that causes the roller assembly to translate toward and engage the driver to initiate driving engagement between the driver and the flywheel; The actuator is a solenoid having a body and a plunger that is being movable along an actuator axis

Methodology Applied
Scientific EffectSolenoid: Solenoid

Implementation Method 2

a multi-angled follower arm and stall release lever, featuring a solenoid-actuated roller assembly that provides non-linear displacement

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP2716409B1Activation system having multi-angled arm and stall release mechanism
Publication Date: 2019.03.27 BLACK & DECKER CORP
  • EP2716409B1 patent drawingFigure 1
  • EP2716409B1 patent drawingFigure 2
  • EP2716409B1 patent drawingFigure 3

AI summary

A power tool including an activation arm assembly having an actuator coupled to the activation arm assembly, the activation arm assembly being coupled to the structure and including a roller assembly having a roller, wherein actuation of the actuator causes the roller assembly to translate toward and engage the driver to initiate driving engagement between the driver and the flywheel; The activation arm assembly further includes a follower arm that engages the roller, the follower arm including a first mounting portion and a second mounting portion, the second mounting portion being pivotally coupled to the actuator and slidingly engaged with the carriage, the first mounting portion being biased in a direction toward the driver. The follower arm has a non-linear profile.