Handheld Fluid Meter Valve Cartridge for Leak-Free Dispensing

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Solution Overview

Problem

Current handheld fluid meters for dispensing automotive fluids face issues such as valve sticking due to pressure imbalances, leakage from dynamic seals, and the complexity of replacing the valve, which can lead to false leak indications.

Innovation Solution

The design incorporates a valve cartridge with a control seat and a valve stem featuring a control seal, which engages and disengages with the control seat to control fluid flow. Additionally, the nozzle includes an overmolded tip seal and a cone-shaped passage to prevent leakage and ensure precise fluid dispensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a manual valve with trigger control is used, then fluid flow can be controlled on and off, but the valve can become stuck in the open position due to pressure imbalances

Engineering Contradiction:
Improvevalve control reliabilityVSAvoidvalve operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

A balanced valve design with equalized pressure chambers is introduced as an intermediary mechanism. The valve incorporates pressure balance holes that equalize pressure on both sides of the valve disc, preventing pressure-induced sticking. This mediator mechanism allows the valve to respond reliably to trigger actuation without being stuck by pressure imbalances.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the valve is quickly modulated between slightly-open and slightly-closed positions, then fluid dispensing can be controlled, but scarfing occurs when the control seal encounters sharp edge geometry

Engineering Contradiction:
Improvefluid dispensing controlVSAvoidcontrol seal durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control seat geometry is modified with rounded transitions and radiused edges at the sealing surfaces. This local quality change eliminates sharp edges that cause scarfing of the control seal during rapid modulation. The rounded geometry allows the seal to glide smoothly during quick opening and closing operations, maintaining reliability while enabling precise fluid dispensing control.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the handheld meter is set on the ground for user input, then the user interface can be accessed, but the display screen is susceptible to damage if the meter is dropped or collides with an object

Engineering Contradiction:
Improveuser interface accessVSAvoiddisplay screen protection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The user interface is repositioned from the ground-level handle area to the upper portion of the meter body, near the fluid inlet. This dimensional relocation allows users to access the interface while holding the meter in a natural position, eliminating the need to set the meter on the ground. The elevated position also naturally protects the display screen from ground-level impacts and drops.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Productivity

If the nozzle stem uses a rounded steel seat, then fluid can be dispensed, but leakage occurs when contaminants are present in the fluid

Engineering Contradiction:
Improvefluid dispensingVSAvoidnozzle sealing
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The nozzle stem sealing system uses a composite approach with a soft elastomeric seal seated against a hardened, precision-machined seat surface. The elastomeric material provides compliance to accommodate contaminants and surface irregularities, while the hardened seat provides structural integrity. This composite sealing system maintains reliable leakage-free operation even when contaminants are present in the dispensed fluid.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP4289782B1Dispensing meter for fluid dispensing
Publication Date: 2025.02.12 GRACO MINNESTOA INC
  • EP4289782B1 patent drawingFigure 1A
  • EP4289782B1 patent drawingFigure 1B
  • EP4289782B1 patent drawingFigure 2A

AI summary

A handheld fluid meter includes a cartridge valve controlling the flow of fluid through the handheld meter. The cartridge valve includes a valve cartridge and a valve stem disposed within the valve cartridge. The cartridge valve guides the valve stem and provides the only sealing surface for the dynamic seals and control seal disposed on the valve stem. The handheld meter dispenses through a nozzle, which includes an overmolded stem tip that generates a laminar fluid flow as the fluid exits the nozzle. The overmolded stem tip is a compliant material. The handheld fluid meter includes circuitry configured to invert the orientation of a visual output provided by a display of the handheld fluid meter to facilitate installation of the handheld fluid meter for use in an oil bar application.