Gas Spring-Powered Fastener Driver With Nested Cylinder-Piston Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing fastener drivers face power, size, and cost constraints, particularly those not utilizing compressed air or electrical energy.

Innovation Solution

A gas spring-powered fastener driver with an inner and outer cylinder, a moveable piston, and a driver blade, utilizing a gas spring mechanism for power and a lifting assembly for driving fasteners, with features like a damping system and torque-limiting clutch mechanism to manage forces and extend lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a gas spring-powered mechanism is used instead of compressed air or electrical energy, then power and cost constraints are improved, but the device complexity increases due to the need for cylinder-piston-lifter mechanisms

Engineering Contradiction:
Improvepower source efficiencyVSAvoidmechanism complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent implements nesting by placing the piston inside the cylinder, and the lifter mechanism inside the cylinder-piston assembly. The driver blade is nested within the lifter mechanism. This nested arrangement consolidates multiple functional components into a compact integrated structure, achieving power source efficiency while controlling device complexity through spatial consolidation rather than separate components.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If a lifting assembly is added to move the driver blade from BDC to TDC, then the fastening functionality is improved, but the device complexity and number of parts increase

Engineering Contradiction:
Improvefastening functionalityVSAvoidnumber of parts
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the lifting function with the existing cylinder-piston mechanism by having the piston directly drive the driver blade upward during its reciprocating motion. The lifter assembly is integrated with the piston-cylinder system rather than being a separate mechanism, combining multiple functions (power storage, driver movement, and lifting) into a unified structure that improves ease of operation while minimizing the number of parts.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If damping elements are positioned between the housing and moving components, then reliability is improved by reducing wear, but the device complexity increases

Engineering Contradiction:
Improvecomponent lifespanVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies beforehand cushioning by positioning damping elements between the housing and moving components (cylinder, transmission, motor) before impact or stress occurs. These damping elements absorb shock and reduce wear during normal operation, extending component lifespan. The damping elements are integrated into the housing structure rather than being separate attachments, improving reliability while minimizing structural complexity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 gas spring-powered fastener driver provides efficient and durable fastening operations with reduced wear and tear, capable of driving fasteners effectively while minimizing stress on components, thus extending the device's lifespan.

Implementation Method 1

Gas spring-powered fastener driver

Methodology Applied
Scientific EffectGas spring: Spring

Implementation Method 2

A bumper is positioned in the cylinder and configured to absorb impact energy from the piston when the driver blade is driven toward the BDC position

Methodology Applied
Scientific EffectImpact energy absorption: Damping

Implementation Method 3

A plurality of damping elements is positioned between the housing and at least one of the inner cylinder, the transmission, or the motor

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP4072786B1Gas spring-powered fastener driver
Publication Date: 2025.09.10 MILWAUKEE ELECTRIC TOOL CORP
  • EP4072786B1 patent drawingFigure 1
  • EP4072786B1 patent drawingFigure 2
  • EP4072786B1 patent drawingFigure 3

AI summary

A gas spring-powered fastener driver includes an outer cylinder and an inner cylinder positioned within the outer cylinder. A moveable piston is positioned within the inner cylinder. A driver blade is attached to the piston and movable therewith between a top-dead-center (TDC) position and a driven or bottom-dead-center (BDC) position. A retaining member is secured to the inner cylinder. The retaining member couples the inner cylinder to the outer cylinder. The inner cylinder is axially secured to the outer cylinder relative to a driving axis defined by the driver blade. The outer cylinder is rotatable relative to the inner cylinder.