Pneumatic Grain Level Sensor Using Pressurized Tube
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Solution Overview
Problem
Existing methods for determining the grain level in agricultural tanks are either complex, costly, or unreliable, particularly when exposed to environmental factors like sunlight and heat, and do not provide continuous measurement of grain accumulation.
Innovation Solution
A grain level sensor system using a closed-end tube with spaced openings within the tank, pressurized by a pneumatic pump and monitored by a pressure sensor, which continuously measures grain accumulation by sensing pressure changes as the openings are covered by grain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a window providing visual indication is used to determine grain level, then the operator can see when the tank is nearly full, but the operator is distracted from operating the complex machinery
Solution Approach 1:
The patent replaces the mechanical/visual window-based level indication system with an automated pneumatic sensing system. A tube with openings along its length is connected to a bellows mechanism that automatically detects grain level through pressure changes, eliminating the need for the operator to visually monitor the tank while maintaining accurate level detection.
2Measurement precision
If pressure level switches at various locations are installed to indicate grain levels, then the tank fullness can be monitored at multiple levels, but the device complexity and cost increase
Solution Approach 1:
The patent merges multiple discrete pressure level switch functions into a single integrated pneumatic sensing system. One tube with multiple openings along its length replaces numerous separate pressure switches, providing continuous grain level indication through a single bellows mechanism while reducing system complexity and cost.
Solution Approach 2:
The single tube-bellows assembly performs multiple functions: it detects grain levels at various heights along the tube length, provides continuous monitoring, and eliminates the need for multiple separate sensing devices. The system universally handles level detection throughout the entire tank height range.
3Measurement precision
If ultrasonic or radar detectors are used to determine tank fullness, then accurate grain level measurement is achieved, but the cost and complexity increase significantly
Solution Approach 1:
The patent employs a simple, inexpensive pneumatic sensing system using basic components (tube, bellows, pressure mechanism) instead of expensive ultrasonic or radar detectors. While the individual components are simple and potentially replaceable, the overall system provides accurate grain level measurement at a fraction of the cost of electronic sensing systems.
4Measurement precision
If a collapsible rubber tube is used to measure grain level, then the tube can be compressed by grain material to indicate level, but the rubber tube is affected by sunlight and heat in harvesters reducing its lifetime
Solution Approach 1:
The patent uses a flexible tube within a rigid support channel structure. The tube maintains its flexibility for compression by grain while the external channel provides structural protection from environmental factors like sunlight and heat, extending the system's operational lifetime in harsh harvester conditions.
Solution Approach 2:
The rigid support channel acts as an intermediary between the flexible sensing tube and the harsh external environment. It transmits the mechanical compression from grain to the bellows mechanism while shielding the vulnerable rubber tube from direct exposure to sunlight and heat that would otherwise degrade it.
5Measurement precision
If air is blown into vertical tubes to monitor material presence, then the pressure indicates blocking by material, but no reliable data about other levels is provided unless further tubes are installed
Solution Approach 1:
The patent segments the single sensing tube into multiple functional zones by placing openings at different heights along its length. Each opening or section detects material presence at a specific level, providing comprehensive multi-level grain detection through one integrated tube rather than requiring multiple separate tubes.
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 provides a continuous, reliable, and cost-effective measurement of grain quantity using minimal hardware, reducing the risk of damage from external contact and maintaining accuracy across varying environmental conditions.
Implementation Method 1
A pneumatic pressure supply, such as a pneumatic pump, pressurizes the interior of the tube and a pressure sensor is provided for sensing the interior pressure
Implementation Method 2
grain building up therein selectively covers the plurality of openings to cause an increase in sensed pressure
Data Source
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AI summary
A combine (12) including a frame (12), power unit (32) and a crop gathering and processing device (18, 20, 24, 26). A grain tank (28) is mounted on the frame (12). An elongated closed end tube (74) is vertically oriented within the grain tank (28) and has a plurality of uniformly spaced openings (76) along its length. A pneumatic pressure supply (86) pressurizes the interior of the tube (74). A pressure sensor (84) senses the interior pressure of the elongated tube (74), so that grain building up therein selectively covers the plurality of openings (76) to cause a proportionate increase in air pressure.