Pivoting Drag Box Blade for Manhole Obstacle Navigation

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Solution Overview

Problem

Drag boxes with curved blades mounted to the rear can get stuck on elevated manhole covers during road resurfacing, causing damage to the blade, tractor, and operator, due to their inability to navigate obstacles effectively.

Innovation Solution

A pivotally mounted flat vertical scraping blade with side shoes and resilient cushion support bars allows the drag box to tilt and ride over obstacles, combined with removable water tanks for added weight and dust suppression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a curved blade is used to remove loose material on soft surfaces, then the blade is effective for grading level soil beds, but the blade gets stuck on elevated manhole covers during road resurfacing operations

Engineering Contradiction:

Improveblade effectiveness for soft surfacesVSAvoidblade ability to navigate obstacles

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The blade is made pivotally mounted rather than fixed, allowing it to dynamically adjust its angle and position when encountering obstacles like manhole covers. This pivotal movement enables the blade to lift and ride over obstacles without getting stuck, while maintaining its curved shape for effective soil grading when on flat surfaces.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The blade angle and position parameters are changed dynamically through pivotal movement. When the blade encounters an obstacle, the pivot mechanism changes the blade's angular parameter, allowing it to transition from a horizontal scraping position to an elevated position that clears the obstacle.

Inventive Principle:

Principle #35Parameter changes

2Strength

If a fixed blade is used to maintain stable structure, then the blade structure is simple and strong, but the blade cannot adapt to different terrain conditions and obstacles

Engineering Contradiction:

Improveblade structural strengthVSAvoidblade adaptability to terrain variations

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The blade mounting system transitions from a fixed rigid connection to a dynamic pivotal connection. This allows the blade to maintain its strong structural integrity while gaining the ability to rotate and adapt to different terrain conditions and obstacle heights during operation.

Inventive Principle:

Principle #15Dynamics

3Reliability

If a pivotally mounted blade is used to navigate obstacles, then the blade can ride over manhole covers, but the blade box frame requires additional cushion support mechanisms

Engineering Contradiction:

Improveblade ability to navigate obstaclesVSAvoidblade box frame support structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Cushion support bars are pre-installed on the blade box frame to provide ahead-of-time cushioning and support during pivotal movement. These cushions absorb shocks and provide mechanical support when the blade encounters obstacles, preventing damage to the frame while enabling the pivotal action.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Object-affected harmful factors

If water tanks are added to the three point hitch for dust suppression, then dust control is improved, but the overall system weight increases

Engineering Contradiction:

Improvedust suppression effectivenessVSAvoiddrag box system weight

Core Design Contradiction:

Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The three-point hitch system is designed to serve multiple functions: it provides structural support for the drag box, enables pivotal movement for obstacle navigation, and serves as a mounting platform for water tanks used in dust suppression. This multi-functionality allows weight addition for dust control without requiring separate support structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables the drag box to safely navigate rigid objects like manhole covers, preventing damage and maintaining operational efficiency while providing effective dust suppression.

Implementation Method 1

Each of the cushion support bars has a resilient cushion mounted thereon positioned for resting on blade box frame support members. The drag box frame and blade is thus allowed to move relative to the three point hitch frame when the box frame main scraping edge contacts an obstacle thereby tilting the blade to ride over the obstacle.

Methodology Applied

Scientific EffectResilient cushioning: Elasticity

Data Source

PatentUS10662593B1Drag box apparatus

Publication Date: 2020.05.26 SMITH KEITH E

AI summary

A drag box or box scraper for scraping and moving loose materials on a surface uses a three point hitch having a pivotally mounted blade box holding a scraping blade attached thereto to allow the scraping blade to pivot to ride over rigid objects, such as man hole covers during road preparations. Attached water tanks add weight to the drag box and feeds a water sprayer used for dust suppression.