Sheet Dispenser Roller and Motor Control to Prevent Jamming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional automated sheet product dispensers experience paper jamming and excessive wear due to abrupt motor speed changes and failure to disengage the sheet from the tear bar, leading to inefficient dispensing and product damage.
Innovation Solution
The use of a DC stepper motor with controlled acceleration and deceleration during the dispensing cycle, combined with a roller assembly featuring flexible rubber portions and a baffle to prevent overspin, along with a modular design that includes a pair of support arms and shaft plugs with springs for improved stability and assembly, minimizes jamming and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If electric drive motors are used with abrupt activation and deactivation during dispensing, then the dispensing mechanism can be simple and responsive, but paper jamming and excessive parts wear occur
Solution Approach 1:
The patent applies dynamics by implementing gradually increasing acceleration and decreasing deceleration during the dispensing cycle. The motor speed is dynamically adjusted throughout the cycle rather than maintaining constant speed or abrupt changes. This dynamic speed control prevents paper jamming and reduces parts wear while maintaining dispensing functionality.
Solution Approach 2:
The patent changes the speed parameter over time during the dispensing cycle. Specifically, acceleration increases gradually during the initial phase and deceleration decreases gradually toward the end of the cycle. This parameter modification resolves the contradiction between simple responsive dispensing and reliable operation without jamming or excessive wear.
2Productivity
If the sheet product remains engaged with the tear bar after dispensing, then the dispense cycle can be simple, but jamming occurs during subsequent cycles
Solution Approach 1:
The patent applies preliminary action by implementing a reverse rotation phase after the main dispensing cycle. This reverse action pulls the paper product away from the tear bar before the next dispense cycle begins, preventing jamming in subsequent operations while maintaining simple dispensing mechanics.
3Device complexity
If conventional motor control is used, then the device complexity is low, but impulse loads are transferred to system components and paper product
Solution Approach 1:
The patent uses dynamic motor control with gradually varying acceleration and deceleration profiles. This dynamic approach reduces impulse loads transferred to the paper product and system components while maintaining relatively simple control system architecture. The gradual transitions eliminate sudden force spikes that would otherwise damage components or product.
Data Source
AI summary
A roller for a sheet product dispenser includes a roller shaft, a roller frame molded onto the roller shaft, and a plurality of flexible rubber portions overmolded onto the roller frame and spaced along a length of the roller frame. The rubber portions are configured to contact a sheet product for dispensing from the sheet product dispenser. A dispensing mechanism for a sheet product dispenser includes a chassis and a roller positioned within and coupled to the chassis. The roller includes a roller shaft, a roller frame molded onto the roller shaft, and a plurality of flexible rubber portions overmolded onto the roller frame and spaced along a length of the roller frame. The rubber portions are configured to contact a sheet product for dispensing from the sheet product dispenser.