Low Profile Drop Table Scissor Lift Mechanism
Solution Overview
Problem
Existing low profile railway drop tables require deep pits, making them hazardous and impractical due to increased soil moisture issues and regulatory constraints, and they often need deeper pits to accommodate rail heights and traversing functions.
Innovation Solution
A lifting apparatus with two spaced rails and two lifting mechanisms, allowing horizontal movement of a platform and vertical displacement of the rails, utilizing a support mechanism with a gearbox or threaded members to minimize pit depth and enable installation in shallower conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional lifting mechanisms with rails are used, then the machinery can perform rail maintenance operations, but the pit depth must be large (greater than 6 feet) to accommodate rail height and traversing function
Solution Approach 1:
The lifting mechanism transitions from a traditional vertical rail-based system to a scissor-like articulated structure that achieves vertical lifting through angular changes. This dimensional transformation allows the mechanism to achieve the necessary lifting height without requiring proportional pit depth, as the scissor arms can fold and extend in a compact configuration that fits within shallow pits while maintaining full lifting capability.
Solution Approach 2:
The scissor-like structure employs dynamic articulated joints that allow the mechanism to adapt its configuration during operation. The arms can fold inward during traversal between track sections and extend outward during lifting operations, enabling the machinery to perform maintenance functions in shallow pits without requiring fixed deep rail installations. This dynamic reconfiguration replaces the static deep-pit requirement with adaptive motion sequences.
2Ease of manufacture
If deeper pits are used to accommodate traditional lifting mechanisms, then the machinery can be installed, but safety hazards increase and regulatory compliance becomes more difficult
Solution Approach 1:
The invention fundamentally changes the depth parameter of the installation environment by using a scissor-like lifting mechanism that achieves full lifting functionality in shallow pits (less than 6 feet) compared to traditional mechanisms requiring deep pits. This parameter change directly reduces the depth-related safety hazards while maintaining installation feasibility through the compact folded configuration of the scissor arms during non-operational states.
3Ease of manufacture
If deeper pits are excavated to accommodate traditional mechanisms, then installation is possible, but soil moisture and groundwater issues increase making installation more difficult
Solution Approach 1:
The scissor-like lifting mechanism changes the depth parameter of installation from traditional deep pits to shallow pits, directly reducing the volume of soil that contains problematic moisture and groundwater. By requiring less excavation depth, the mechanism avoids the moisture-rich zones that would otherwise complicate installation and ongoing operation, thereby improving installation feasibility in challenging soil conditions.
4Ease of operation
If traditional lifting mechanisms are used, then lifting function is achieved, but the profile height is large requiring deeper pits
Solution Approach 1:
The scissor-like arms are designed to nest within each other when folded, with the smaller arms fitting inside the larger arms during the retracted configuration. This nesting arrangement minimizes the overall profile height of the mechanism when not in use, allowing installation in shallow pits while maintaining full lifting capability when the arms are extended. The nested configuration directly reduces the vertical space requirement compared to traditional extended mechanisms.
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 apparatus achieves a more compact footprint, reduces pit depth, and allows installation in areas with soil or groundwater constraints, enhancing safety and installation ease while maintaining sufficient travel range for rail maintenance.
Implementation Method 1
the support mechanism includes a column and a gearbox rotatable by a drive wherein rotation of the gearbox causes vertical displacement of the column
Implementation Method 2
the support mechanism includes a threaded member rotatable by a drive, the threaded member having two threaded blocks threaded therearound such that rotation of the threaded member causes a distance between the two threaded blocks to change
Data Source
AI summary
A lifting apparatus having two rails spaced apart at a distance and two lifting mechanisms, each lifting mechanism supporting one of the two rails. A platform is disposed between the two rails such that movement of the lifting mechanisms causes the rails to displace relative to the platform. A base has the two lifting mechanisms connected thereto and the platform is connected to the base. The base moves horizontally along a floor. Further, the floor may be disposed in a pit and the travel of the rails between minimum and maximum rail heights may be greater than 62.5% of the depth of the pit. The minimum rail height may be less than 50% of the depth of the pit.