Drop-Arm Barrier Shaft Protection Against Vehicular Shear
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Solution Overview
Problem
Existing barriers, particularly those involving vehicular traffic, often fail to provide adequate protection against shear forces and mechanical shear, and existing vehicular barriers fail to prevent shear forces and mechanical shear, and existing vehicular barriers fail to prevent shear forces and mechanical shear, and existing vehicular barriers fail to prevent shear forces and mechanical shear.
Innovation Solution
A barrier system comprising an elongate arm supported by an actuator and receiver, with a rotatable shaft and shear-resistant structures within an internal chamber to absorb and dissipate collision energy, preventing structural failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple shaft support structure is used, then the device complexity is reduced, but the barrier fails to prevent shear forces and mechanical shear during vehicular impacts
Solution Approach 1:
The shear-resistant structure is nested within the internal chamber of the column, with the shaft extending through the arm and column while the shear-resistant structure is positioned within the column's internal chamber in shear-receiving relationship to the shaft. This nested arrangement provides enhanced protection against shear forces without significantly increasing overall device complexity.
Solution Approach 2:
The shear-resistant structure acts as an intermediary element between the shaft and the column, specifically designed to receive and resist shear forces during vehicular impacts. This intermediary structure prevents direct transmission of shear forces to the shaft, thereby preventing structural failure while maintaining a relatively simple overall design.
2Strength
If the shaft is made more robust to prevent shearing, then the strength increases, but the device complexity and material usage increase
Solution Approach 1:
Instead of making the shaft itself more robust to resist shear forces, the patent introduces a shear-resistant structure as an intermediary element that performs this function. The shaft maintains its simpler, lighter design while the shear-resistant structure positioned within the column's internal chamber provides the necessary shear protection.
Solution Approach 2:
The shear resistance function is segmented from the shaft structure and assigned to a separate shear-resistant structure. This allows the shaft to be optimized for its primary function (rotational support) while the shear-resistant structure handles shear forces independently, reducing overall device complexity compared to a monolithic robust shaft design.
3Reliability
If the column internal chamber is added to house shear-resistant structure, then the barrier reliability improves, but the device complexity increases
Solution Approach 1:
The shear-resistant structure is nested within the internal chamber of the column, utilizing the existing column space to house the additional protective element. This nesting approach provides enhanced structural integrity during impacts while minimizing the increase in overall device complexity by avoiding external additions.
Solution Approach 2:
The column's internal chamber serves multiple functions: it provides structural support for the column itself and simultaneously houses the shear-resistant structure that protects the shaft during vehicular impacts. This multi-functionality reduces the need for separate external structures, thereby limiting the increase in device 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
The system effectively absorbs and dissipates collision energy, maintaining structural integrity and preventing the shaft from being pulled out or snapped, thereby ensuring the barrier remains operational during vehicular impacts.
Implementation Method 1
The at least one shear-resistant structure is positionable within the internal chamber in shear-receiving relationship to the shaft
Data Source
AI summary
A drop-arm barrier features an elongate arm supported on a shaft. The shaft and the arm rotate as a unit. At its opposite ends, the shaft is supported at an elevated position by a pair of vertical and hollow columns. A bearing within each column supports the shaft. Also received within the column are a plurality of shear-resistant structures. These structures help to dissipate shear energy that might be transmitted to the shaft as a result of a vehicular collision with the arm. The shear-resistant structures include first and second shear plates, which are threaded onto the shaft, and a shear pin, which extends orthogonally through the shaft.