Variable Pinch Valve for Precise Multi-Fluid Flow Restriction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluid management systems that rely on variable rate pumps for fluid flow regulation are costly and require multiple pumps and actuators for each fluid, leading to increased weight and expense.
Innovation Solution
A variable flow restrictor using a variable pinch valve that progressively pinches a tube, creating a gradually-increasing mechanical advantage to control fluid flow, allowing for precise regulation of multiple fluids with a single pump and valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If variable rate pumps are used to regulate fluid flow rates, then precise flow control is achieved, but system cost and device complexity increase significantly
Solution Approach 1:
The patent replaces complex variable rate pumps with a simpler system combining a constant rate pump and passive flow restrictors. The flow regulation function is transferred from active pump control to passive mechanical flow restrictors that create predictable pressure drops, eliminating the need for complex pump mechanisms while maintaining precise flow control.
Solution Approach 2:
The patent introduces flow restrictors as intermediary components between the pump and the fluid delivery system. These restrictors act as mediators that convert the constant pump output into variable, precisely controlled flow rates through their resistance characteristics, without requiring the pump itself to be variable.
2Adaptability or versatility
If multiple separate pumps are used for multiple fluids, then each fluid can be regulated independently, but system weight and cost increase
Solution Approach 1:
The patent merges multiple fluid delivery functions into a single integrated system. One constant rate pump serves multiple fluid pathways, with each pathway having its own passive flow restrictor. This consolidation eliminates the need for multiple separate pumps while maintaining independent flow regulation capability through the restrictor network.
Solution Approach 2:
The single pump in the patent performs multiple functions by supplying different fluids to different pathways simultaneously. The flow restrictors provide the differentiation and regulation for each fluid type, allowing one pump to replace what would traditionally require multiple specialized pumps.
3Measurement precision
If multiple separate actuators are used for each fluid circuit, then precise control of each fluid is achieved, but device complexity and cost increase
Solution Approach 1:
The patent replaces active actuator mechanisms with passive mechanical flow restrictors. The restrictors are designed with specific geometries that create predictable flow resistance characteristics, providing precise flow control without requiring motors, sensors, or control electronics. This mechanical substitution dramatically reduces device complexity while maintaining precision.
4Device complexity
If variable flow restrictors are used instead of multiple pumps, then system cost and weight are reduced, but flow control precision must be maintained
Solution Approach 1:
The patent achieves variable flow control by changing the resistance parameters of the flow restrictors rather than changing pump speed. Each restrictor is designed with specific geometric parameters (aperture size, shape, length) that determine its flow characteristics. By selecting appropriate restrictor parameters, precise flow rates are achieved passively.
Solution Approach 2:
The patent segments the flow control function into multiple independent restrictor elements, each handling a specific fluid pathway. This segmentation allows each restrictor to be optimized for its specific function while the overall system achieves complex multi-fluid regulation through the combination of simple individual components.
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 enables efficient and precise control of fluid flow for multiple fluids, reducing the need for multiple pumps and actuators, thereby decreasing weight and cost while maintaining effective flow regulation.
Implementation Method 1
The pinching element creates a gradually-increasing mechanical advantage that increases the force pinching the tube as the tube approaches full occlusion
Data Source
Figure 1A~1F
Figure 2A~2D
Figure 3
AI summary
A flow restrictor includes a flexible tube held in a housing and a linear actuator connected through an intermediate link to a distal link via a first revolute joint proximate the linear actuator and a second revolute joint connecting the intermediate and distal links. The distal link has a distal end adjacent the flexible tube and the intermediate and distal links are constrained to move such that when the linear actuator moves the first revolute joint toward the linear actuator, the distal end of the distal link is driven into the side of the tube thereby progressively occluding the flexible tube.