Mechanical Bin-Full Sensor for Paper Shredder Motor Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing paper shredders face challenges with complex and inflexible mechanical paper-full detection devices, which are costly and prone to damage, and electronic devices are expensive and unstable, necessitating a simple, durable, and cost-effective solution for paper-full detection and power-off protection.
Innovation Solution
A mechanical bin-full detector system using a T-blade sensor coupled to an electric motor, which rotates to select an electrical contact to stop the motor when shreddant reaches a predetermined level in the bin, incorporating a microcontroller to manage the power-off function and integrate with safety and time-delay switches for efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical paper-full detection device is used, then the detection function is achieved, but the structure becomes complicated and the device becomes inflexible to use
Solution Approach 1:
The T-blade sensor is divided into functionally independent segments: the cylindrical body with electrical sensor, the pendent blade indicator, and the electrical contacts on the shredder element. This segmentation allows each component to perform its specific function independently, simplifying the overall structure while maintaining the paper-full detection capability.
Solution Approach 2:
The T-blade sensor serves multiple functions: it acts as both a level indicator (the pendent blade rotates to indicate bin-full status) and an electrical switch (the electrical sensor contacts the electrical contacts to stop the motor). This multi-functionality eliminates the need for separate detection and control mechanisms, reducing structural complexity.
2Measurement precision
If an electronic paper-full detection device is used, then the detection accuracy is improved, but the cost increases and stability deteriorates
Solution Approach 1:
The patent replaces complex electronic detection systems with a simple mechanical T-blade sensor system. The pendent blade's rotation mechanically indicates the bin-full status, and the electrical contact provides a reliable, simple switching mechanism. This mechanical approach eliminates the cost and stability issues associated with electronic sensors while maintaining adequate detection precision.
3Reliability
If separate time-delay switch and safety switch are installed, then the power-off protection function is achieved, but the number of parts increases and manufacturing cost increases
Solution Approach 1:
The T-blade sensor integrates the safety switch and time-delay switch functions into a single device. The electrical sensor and electrical contacts work together to provide both the power-off protection when the bin is full and the time-delay functionality, eliminating the need for separate switches and reducing the total number of parts.
Solution Approach 2:
The integrated T-blade sensor system performs multiple protective functions: it detects bin-full status, stops the motor to prevent damage, and provides time-delay control. This multi-functionality consolidates what would traditionally require separate components, reducing manufacturing cost and simplifying the overall device structure.
Data Source
AI summary
A mechanical bin-full device for a paper shredder with a bin, having a curved, perforated T-blade sensor on a cylindrical body partially covered with a metal sheet. The T-blade is pendent into the bin. Metal contacts are placed on the paper shredder near the metal sheet, forming a switch, which is coupled to a motor control circuit for the shredder motor. The T-blade is pushed by paper shreddant and rotates the cylinder body as paper shreddant fills the bin. When the bin becomes full, the T-blade is positioned so that the metal contacts touch the metal sheet, closing the control circuit switch, and causing the motor to cease operating. The control circuit can include a microcontroller coupled to the motor, or a transistor-based driver coupled to a motor relay.