Grease Gun Return Valve for Pressure Relief and Grease Recovery

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Solution Overview

Problem

Existing grease guns waste grease due to pressure drops and trapped air pockets in the delivery line, leading to inefficiency, environmental hazards, and operator frustration with Zerk couplers becoming stuck.

Innovation Solution

A manual grease gun with an integrated valve system that allows for the return of grease under pressure from the delivery line back to the reservoir, featuring a piston-operated pressure chamber with a one-way flow control valve and a pressure return port, and a stroke limiter to prevent unintended retraction during normal cycles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If high pressure is used to deliver grease through the delivery line, then grease can overcome high resistance in tight tolerances and blockages, but the delivery line swells and absorbs extra grease which is then wasted when pressure drops

Engineering Contradiction:
ImprovepressureVSAvoidgrease waste
Core Design Contradiction:
Stress or pressureVSLoss of substance

Solution Approach 1:

The invention extracts the excess grease that has been forced into the delivery line under high pressure by providing a separate return passage that leads back to the grease reservoir. This allows the grease to be removed from the system before it can be wasted, directly addressing the contradiction between high pressure delivery and grease conservation

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The return passage acts as an intermediary pathway between the delivery line and the grease reservoir. Instead of allowing grease to be wasted directly to the environment, the return passage provides a controlled route back to the reservoir, mediating the transition from high-pressure delivery to low-pressure storage

Inventive Principle:
Principle #24Intermediary (Mediator)

2Force

If pressure is maintained in the delivery line after greasing, then the coupler grips the grease nipple firmly, but the operator must vigorously oscillate the coupler to release it, causing damage and grease waste

Engineering Contradiction:
Improvecoupler grip forceVSAvoidcoupler release difficulty
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The invention performs the pressure release action in advance of the coupler release. By providing a return passage that can be activated before the coupler is removed, the system preliminarily reduces the pressure that would otherwise require vigorous oscillation to overcome, making the release process easier and less damaging

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention segments the pressure control function from the coupler coupling function. The return passage provides a separate mechanism for pressure management that is independent of the mechanical coupling between the coupler and grease nipple, allowing pressure to be controlled without affecting the coupling integrity

Inventive Principle:
Principle #1Segmentation

3Duration of action of moving object

If the delivery line is released from the grease nipple, then the greasing cycle is complete, but air pockets expand and displace grease out the end of the delivery line, increasing waste

Engineering Contradiction:
Improvegreasing cycle completionVSAvoidgrease waste from air pockets
Core Design Contradiction:
Duration of action of moving objectVSLoss of substance

Solution Approach 1:

The invention extracts air pockets from the high-pressure delivery environment by providing a return passage that allows trapped air to escape back to the reservoir. This prevents the air pockets from expanding and displacing grease when the delivery line is released, directly addressing the waste problem

Inventive Principle:
Principle #2Taking out (Extraction)

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

Significantly reduces grease waste, extends the life of grease couplers and nipples, and decreases operator frustration by allowing easy disconnection without grease loss, thus enhancing operational efficiency and safety.

Implementation Method 1

a one-way flow control valve located between the pressure chamber and the grease outlet port to inhibit the reverse flow of the grease from the grease outlet port back into the pressure chamber

Methodology Applied
Scientific EffectOne-way flow control valve: Valve

Implementation Method 2

a piston operable within the pressure chamber for displacing the grease from the grease inlet port through the pressure chamber to the grease outlet port

Methodology Applied
Scientific EffectPiston displacement: Mechanical Force

Implementation Method 3

a pressure return port located upstream of the grease inlet port and linked to the grease outlet port by a pressure return passage, the pressure return port being openable into the pressure chamber, for returning the grease under pressure to the pressure chamber and subsequently to the grease reservoir

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3671004B1Grease gun pressure return valve
Publication Date: 2021.12.22 GURTECH
  • EP3671004B1 patent drawingFigure 1A~1B
  • EP3671004B1 patent drawingFigure 2
  • EP3671004B1 patent drawingFigure 3

AI summary

The invention provides an apparatus comprising a grease gun (10) having a delivery line (22), the apparatus being configured to return grease under pressure from within the delivery line (22) of the grease gun (10) back to a grease reservoir (14); the grease gun (10) comprising a dispensing head (12) fitted to reservoir (14) containing grease and including a grease inlet port (16), for receiving grease from the grease reservoir (14), a grease outlet port (20) connectable to the delivery line (22) for dispensing grease; a pressure chamber (18) wherein the grease inlet port (16) is in fluid communication with the grease outlet port (20) via the pressure chamber (18); a piston (28) operable for displacing the grease from the grease inlet port (16) to the grease outlet port (20); and a one-way flow control valve located between the pressure chamber and the grease outlet port to inhibit the reverse flow of the grease from the grease outlet port back into the pressure chamber; the dispensing head (12) further comprising a pressure return port (26),located upstream of the grease inlet port (16) and linked to the grease outlet port (20) by a pressure return passage and openable into the pressure chamber (18), for returning the grease under pressure to the pressure chamber (18) and the grease reservoir (14), in which the piston (28) acts as a valve movable between a first position where the pressure return port (26) is closed and a second position where the pressure return port (26) is open.