Compact Pinch Valve for Inkjet Printhead Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printers face challenges in decoupling printheads without ink spillage and in purging air bubbles, as existing pinch valves are complex and require precise motor control for opening and closing ink and air lines.
Innovation Solution
A compact pinch valve design using spring-biased elongate pinch elements and a camshaft mechanism that leverages mechanical advantage to control the flow of ink and air lines, allowing for efficient priming, de-priming, and air bubble purging with reduced motor torque requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a prior art pinch valve uses spring-biased elongate pinch elements with cam mechanism to control ink and air lines, then the valve can selectively direct flow, but the device complexity and motor torque requirements increase
Solution Approach 1:
The patent combines the control of multiple ink lines and air lines into a single integrated pinch valve body. The valve uses a unified cam mechanism that simultaneously controls multiple pinch elements, merging what would traditionally require separate valve assemblies into one compact unit, thereby reducing overall device complexity while maintaining flow control versatility
Solution Approach 2:
The pinch valve is designed as a universal component that can control both ink lines and air lines through a single mechanism. The cam-driven pinch elements can selectively occlude any combination of lines passing through the valve body, making the valve multi-functional and adaptable to different operating modes (priming, de-priming, purging) without requiring separate specialized valves
2Ease of operation
If a prior art pinch valve uses motor-controlled cam mechanism to open and close lines, then flow control is achieved, but the motor torque requirements and control precision increase
Solution Approach 1:
The patent employs curved cam surfaces that translate rotational motion into linear pinch element displacement. The cam geometry is designed to provide mechanical advantage, where the curved profile allows a small rotational input from the motor to generate sufficient linear force for line occlusion, thereby reducing the torque requirements while maintaining precise control
Solution Approach 2:
The cam mechanism acts as an intermediary between the motor and the pinch elements. Instead of the motor directly actuating the pinch elements, the cam converts rotational motion into the appropriate linear displacement and force amplification, serving as a mechanical mediator that reduces the direct torque burden on the motor while achieving precise line control
3Ease of manufacture
Ifprinthead is decoupled from ink lines without de-priming, then replacement is enabled, but ink spillage occurs
Solution Approach 1:
The system enables preliminary de-priming of the printhead through the pinch valve before physical decoupling occurs. By activating the air line through the pinch valve to push ink back into the reservoir, the harmful ink spillage is prevented in advance, allowing safe printhead replacement without compromising the ease of the replacement process
4Reliability
If air bubbles are present in printhead, then printing quality deteriorates, but purging mechanism adds complexity
Solution Approach 1:
The pinch valve serves a dual function: it controls ink flow for normal printing operations and simultaneously provides air bubble purging capability through the air line. By using the same valve mechanism for both ink delivery and air purging, the system achieves reliable printing quality improvement without adding separate dedicated purging hardware, thereby avoiding increased device complexity
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 enables reliable decoupling of printheads without ink spillage and effective purging of air bubbles, improving operational efficiency and user convenience while reducing the complexity of motor control.
Implementation Method 1
The resilient tubing is selectively allowed to open to allow the passage of ink or air through the valve to the printhead
Implementation Method 2
there are 5 ink lines and 5 air lines which are selectively opened and closed by the operation of the pinch valve. The ink lines and air lines pass through the pinch valve and the sections of the lines which pass through the pinch valve are formed of a resilient, plastics tubing
Implementation Method 3
The reciprocation of the elongate pinch elements is controlled by cams which are mounted on a rotatable camshaft which, in turn, is controlled by a motor
Implementation Method 4
A compact pinch valve design using spring-biased elongate pinch elements and a camshaft mechanism that leverages mechanical advantage to control the flow of ink and air lines
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An improved pinch valve includes a camshaft and associated cam(s) controlling the position of a pivotally-mounted first pinch arm and an opposed, pivotally-mounted second pinch arm. The respective pinch arms are provided symmetrically about a central plane which contains an axis of the camshaft. A spring extends across the central plane and interconnects the respective pinch arms so as to urge both pinch arms towards the central plane. A mechanical advantage lever is provided such that the pinching force is greater than the spring force.