Drawback Check Valve for Pump Dispensers
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Solution Overview
Problem
Existing fluid dispensers suffer from issues such as dripping and stringing after use, leading to obstructions and inefficient fluid flow due to hardened liquids and elongated fluid strings, and the manufacturing of pistons for these dispensers is complex.
Innovation Solution
A valve arrangement with a spring member and piston head member that allows for one-way flow and subsequent drawback of fluid, combined with a piston pump featuring a variable length piston chamber formed by a tubular member with resilient properties, enabling axial deflection and fluid flow control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a one-way check valve is used to prevent fluid flow in the upstream direction, then fluid flow control is improved, but fluid dripping from the discharge outlet after use occurs
Solution Approach 1:
The valve member is designed to normally block fluid flow in the downstream direction (opposite of conventional check valves), and only opens when pressure differential exceeds a threshold. This inverted logic prevents dripping by maintaining blockage during low-pressure conditions while allowing flow during high-pressure dispensing operations.
Solution Approach 2:
The valve member's flow blocking capability is changed based on pressure differential parameters. At low pressure differentials (after dispensing), the valve maintains a blocked state to prevent dripping. At high pressure differentials (during dispensing), the valve opens to allow fluid flow. This parameter-based state change resolves the contradiction between flow control and dripping prevention.
2Productivity
If fluid is dispensed through a nozzle, then fluid delivery is achieved, but liquid hardening creates obstructions that reduce future fluid flow area
Solution Approach 1:
The valve performs a preliminary action by blocking fluid flow immediately after dispensing operation. This preliminary blockage prevents residual fluid from hardening and creating obstructions in the passageway, thereby maintaining fluid flow area for future operations. The valve closes automatically when pressure differential drops, executing this protective action without user intervention.
3Ease of operation
If a conventional piston design is used, then pumping function is provided, but manufacturing complexity increases
Solution Approach 1:
The valve member integrates multiple functions into a single component: it serves as both the pumping element (moving back and forth to dispense fluid) and the valve element (blocking fluid flow based on pressure differential). This merging eliminates the need for separate piston and valve components, simplifying manufacturing while maintaining the pumping function.
Solution Approach 2:
The valve member is designed as a multi-functional component that performs both pumping and valve operations. During the forward stroke, it pumps fluid through the passageway; during the return stroke, it blocks fluid flow to prevent dripping. This universality reduces the number of parts and simplifies the overall device structure, improving ease of manufacture.
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 solution reduces dripping and stringing by allowing fluid to be drawn back into the dispenser after use, improving flow efficiency and simplifying the manufacturing process of the piston pump.
Implementation Method 1
a resilient portion of the piston biasing the piston head portion and the piston base portion axially apart
Implementation Method 2
when a pressure on an upstream side of the valve member exceeds a pressure on a downstream side of the valve member
Implementation Method 3
when a pressure on the downstream side of the valve member exceeds a pressure on the upstream side of the valve member
Implementation Method 4
of drawing back some fluid which has been dispensed from the downstream side of the valve member to the upstream side of the valve member
Data Source
AI summary
A valve for a pump arrangement which serves on one hand as a one-way outlet valve subject to functioning, after fluid has been dispensed, of drawing back some fluid which has been dispensed.