Cam Lever Mechanism for Roller Nip Force Control
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Solution Overview
Problem
Existing laminating and printing machines face issues with uneven nip force due to reaction forces causing roller bending, leading to web stretching, tearing, or non-uniform ink transfer and lamination creases, particularly in varying web thickness and operating speeds.
Innovation Solution
A cam and lever mechanism is employed to apply an adjustable torque to journal bearings, counteracting the bending moment caused by nip forces, allowing for proportional adjustment of nip pressure across the roller nip axis, using a lever arm with selectable attachment holes to vary leverage and accommodate different web conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If fixed journal bearings are used to support roller cylinders, then the structure is simple and stable, but the reaction force from frictional driving creates torque that causes roller bending and uneven nip pressure
Solution Approach 1:
The patent applies counterweights to the movable arms supporting the journal bearings. These counterweights generate counter-torques that balance the reaction torques from frictional driving forces, preventing roller bending and maintaining uniform nip pressure across the web throughout the printing cycle.
Solution Approach 2:
The patent transitions from fixed journal bearings to movable journal bearings mounted on movable arms. This dynamic configuration allows the bearing positions to adjust during operation, enabling the application of counter-torques that vary with the printing cycle to maintain consistent roller alignment and nip pressure.
2Manufacturing precision
If crown profiles are used to compensate for roller deflection, then uniform nip pressure can be achieved under fixed conditions, but changing nip pressure reduces uniformity and requires experimentation to adjust
Solution Approach 1:
The patent replaces static crown profiles with dynamic counter-torque mechanisms. The movable arms with counterweights can adjust the counter-torques in real-time during the printing cycle, allowing nip pressure to be varied for different web thicknesses and operating conditions while maintaining uniformity through active control rather than fixed geometry.
Solution Approach 2:
The patent enables dynamic parameter changes in the counter-torque system. By adjusting the counterweight positions and movable arm configurations, the system can adapt counter-torques to match varying operating conditions such as different web thicknesses, speeds, and nip pressure requirements, eliminating the need for physical crown profile changes.
3Manufacturing precision
If intermediate bearings with adjustable eccentric collars are used to produce counterforce, then roller bending can be compensated, but the device complexity increases
Solution Approach 1:
The patent extracts the counter-torque generation function from complex intermediate bearing structures and implements it through simpler counterweights on movable arms. This separates the support function (handled by fixed ends) from the counter-torque function (handled by movable arms with counterweights), achieving bending compensation with reduced structural 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
This solution maintains uniform nip pressure across the roller nip axis, accommodating changes in web thickness and operating speeds, preventing web stretching and ensuring consistent ink transfer and lamination quality.
Implementation Method 1
a cam and lever mechanism is provided to apply an adjustable torque to the journal bearing to produce a bending moment in the cylinders that is counter to the internal bending moment produced by the rolling contact of the cylinders
Implementation Method 2
The frictional driving force on the web produces an equal reaction force on the cylinders
Implementation Method 3
The lever arm on which the cam is mounted has selectable attachment holes to increase or decrease the effective length of leverage
Data Source
AI summary
A device to provide a moment loading to one roller of a pair of nip rollers to counteract the bending moment created by a nip force between the rollers, the one roller being rotatably supported by a journal bearing at each end thereof, the device comprising a lever mechanism for imparting translational and torsional movement to the journal bearing with respect to a frame.