Spray Gun Air Cap Fan Port Layout for Stable Wide Patterns

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing air sprayers lack efficient mechanisms to atomize and shape spray fluid effectively, particularly at high pressures, leading to issues like splitting or tailing of the spray pattern.

Innovation Solution

An air cap for a spray gun is designed with a cap body featuring prongs and fan ports that output compressed gas to atomize and shape the spray fluid, including inner and outer fan ports on each prong to enhance atomization and pattern control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If existing air sprayers are used to spray fluid at high pressures, then the spray fluid can be delivered efficiently, but the spray pattern splits or tails due to ineffective atomization

Engineering Contradiction:
Improvespray material output rateVSAvoidspray pattern quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The air cap is divided into multiple prongs (typically three) with fan ports distributed across them, segmenting the atomization function into multiple zones. This segmentation allows different regions of the spray fluid to be atomized by different prongs, preventing pattern splitting while maintaining high material throughput capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Fan ports are positioned at specific locations on the prongs with varying orientations and angles to address local atomization needs. The fan ports on different prongs are oriented to target specific regions of the spray fluid stream, providing localized quality control that prevents tailing and ensures uniform atomization across the entire spray pattern

Inventive Principle:
Principle #3Local quality

2Reliability

If compressed gas is used to atomize spray fluid, then atomization can be achieved, but the spray pattern may split or tail without proper shaping

Engineering Contradiction:
Improveatomization effectivenessVSAvoidspray pattern consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Each prong is equipped with fan ports oriented at specific angles to address local atomization and shaping needs. The fan ports on opposite prongs are oriented to work together, with one prong's fan ports targeting the upward portion of the spray fluid and the opposite prong's fan ports targeting the downward portion, ensuring consistent pattern formation without splitting or tailing

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fan port configuration provides inherent feedback control for spray pattern formation. The oriented fan ports continuously adjust the compressed gas flow to counteract deviations in spray fluid trajectory, preventing pattern splitting and tailing through real-time aerodynamic feedback rather than mechanical adjustment

Inventive Principle:
Principle #23Feedback

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 air cap can atomize and shape spray fluid up to twice as much material per unit time, generating wider patterns without splitting or tailing, while maintaining efficient atomization and flow rates.

Implementation Method 1

compressed gas emitted from the spray gun atomizes and shapes the fluid output

Methodology Applied
Scientific EffectAtomization:

Implementation Method 2

compressed gas emitted from the spray gun atomizes and shapes the fluid output

Methodology Applied
Scientific EffectGas flow shaping:

Data Source

PatentEP4659864A1Air cap for a fluid spray gun
Publication Date: 2025.12.10 GRACO MINNESTOA INC
  • EP4659864A1 patent drawingFigure 1
  • EP4659864A1 patent drawingFigure 2
  • EP4659864A1 patent drawingFigure 3

AI summary

A spray gun is configured to emit spray fluid and compressed air that impinges on the spray fluid to atomize the spray fluid. An air cap is configured to emit the compressed air. The air cap includes prongs that extend axially away from a fluid spray nozzle. Openings are formed through the prongs and are configured to emit compressed gas onto the fluid output to shape the fluid output. The openings are disposed in a stacked configuration and include openings offset from a spray axis.