Dual-Piston Grease Gun With Automatic Pressure Mode Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing manual grease guns struggle with high greasing pressure due to blockages, requiring significant user effort and difficulty in switching between low volume/high pressure modes, and often necessitate external power sources for additional pressure.

Innovation Solution

A grease gun design with dual pistons and a spool mechanism that automatically adjusts between high flow and high pressure modes, using non-return valves and a pressure-sensitive spool to manage grease flow and pressure, allowing easy operation and efficient grease application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If manual grease guns operate in low volume/high pressure mode to clear blockages, then grease pressure is improved, but user effort and difficulty of operation increase significantly

Engineering Contradiction:
Improvegrease pressureVSAvoiduser effort
Core Design Contradiction:
Stress or pressureVSEase of operation

Solution Approach 1:

A by-pass channel acts as an intermediary pathway that allows excess grease to flow back to the container when operating in high pressure mode. This mediator mechanism reduces the pressure buildup that would otherwise require excessive user effort, enabling the system to achieve high pressure for clearing blockages while maintaining manageable operating forces through the by-pass relief pathway.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes the flow parameters by switching between high volume/low pressure and low volume/high pressure modes. The by-pass channel enables parameter adjustment by allowing grease to recirculate when high pressure is needed, automatically modulating the pressure level to clear blockages without requiring sustained high user effort.

Inventive Principle:
Principle #35Parameter changes

2Stress or pressure

If external power sources are used to provide additional pressure for clearing blockages, then grease pressure is improved, but device complexity and cost increase

Engineering Contradiction:
Improvegrease pressureVSAvoidsystem complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The grease gun system serves itself by incorporating a by-pass channel that automatically allows grease to flow back to the container when high pressure is required. This self-regulating mechanism eliminates the need for external power sources or complex electronic controls, achieving high pressure capability through a simple passive hydraulic by-pass pathway.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The by-pass channel extracts the need for external power sources by providing an internal pressure relief and recirculation pathway. By removing the dependency on external power systems and implementing a self-contained by-pass mechanism, the design achieves high pressure capability while reducing overall system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If grease guns switch between high volume/low pressure and low volume/high pressure modes, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improvemode switching capabilityVSAvoidmechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system dynamically adapts between operating modes through a movable spool that responds to pressure conditions. The spool automatically shifts position based on pressure differential, enabling the system to transition between high volume/low pressure and low volume/high pressure modes without complex electronic controls or multiple separate mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The by-pass channel serves multiple functions: it acts as a pressure relief pathway, a recirculation channel, and a mode-switching mechanism. This multi-functional design enables adaptability between different operating modes while minimizing the number of separate components required, reducing overall device complexity.

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 design provides effortless operation by reducing user effort and effectively clears blockages with adjustable high pressure, while preventing overpressure through a built-in pressure relief valve, ensuring safe and efficient grease application.

Implementation Method 1

The first non-return valve is disposed in the secondary grease channel and allows for grease to flow from the first chamber into the second chamber

Methodology Applied
Scientific EffectOne-way flow control: Valve

Implementation Method 2

a spool moveable within the spool channel between an open position and a closed position... an increase in pressure in the outlet chamber causes an increase in pressure in the pressure channel

Methodology Applied
Scientific EffectPressure sensitivity: Pressure Gradient

Implementation Method 3

a second biasing means disposed at a second end of the spool channel, the second biasing means configured to bias the spool towards the closed position

Methodology Applied
Scientific EffectMechanical biasing: Spring

Implementation Method 4

a pressure differential between the outlet chamber and the by-pass channel causes the spool to move towards the open position

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP4090876B1Grease gun
Publication Date: 2025.10.01 MACNAUGHT PTY LTD
  • EP4090876B1 patent drawingFigure 1
  • EP4090876B1 patent drawingFigure 2
  • EP4090876B1 patent drawingFigure 3

AI summary

A grease gun comprising a body having first and second chambers, first and second pistons within those first and second chambers, primary and secondary grease channels, a grease outlet and an actuator, is provided. Actuation of the actuator by a user causes first and second pistons to move within first and second chambers. The body may further comprise a pressure sensitive spool which allows the grease gun to move from a high flow/low pressure operation to a high pressure/low flow operation when there is a grease blockage that causes an increase in the pressure in the body.