Spring-Mounted Linkage Lifting Device to Prevent Wedging and Collapse
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Solution Overview
Problem
Existing lifting devices face issues with structural reinforcement and wedging due to the moment transfer between the carrying and wheel planes, particularly when loaded, leading to instability and potential wedging during movement.
Innovation Solution
The use of spiral springs mounted on hinge pins between the carrying and wheel planes, which are tensioned as the planes move closer, providing a lifting moment that adjusts with distance, ensuring stable and unobstructed movement while preventing collapse and wedging by allowing rotational movements without linear guides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If springs are positioned in a vertical frame part next to the carrying plane, then the carrying plane can be supported, but the structure requires extra reinforcement and risks wedging during movement
Solution Approach 1:
The invention extracts the springs from the vertical frame part and relocates them to the linkages between the wheel plane and carrying plane. This removes the source of the moment that causes both the reinforcement requirement and the wedging risk, while maintaining the support function through the linkage mechanism.
Solution Approach 2:
Instead of positioning springs vertically beside the carrying plane (conventional approach), the invention inverts the arrangement by mounting springs on the linkages that connect the wheel plane to the carrying plane. This inversion transforms the moment problem into a rotational movement solution, eliminating wedging while maintaining structural integrity.
2Stability of the object's composition
If a linear guide is used for the carrying plane along the vertical frame part, then guidance is provided, but the carrying plane becomes wedged in a given position during motion
Solution Approach 1:
The invention inverts the guidance approach by replacing linear guides with linkages that enable rotational movement. The linkages guide the carrying plane through arc-shaped rotational paths rather than linear motion, eliminating the wedging effect while maintaining stable guidance throughout the lifting cycle.
Solution Approach 2:
The invention transitions from static linear guidance to dynamic rotational guidance through the linkages. The linkages adapt their orientation during movement, allowing the carrying plane to rotate smoothly along an arc path, which prevents wedging while maintaining guidance stability throughout the motion range.
3Stability of the object's composition
If linkages with non-parallel knee hinge lines are used, then parallel guide is ensured, but the structure becomes more complex
Solution Approach 1:
The invention applies asymmetry through non-parallel knee hinge lines in the linkage configuration. This asymmetric arrangement ensures that the linkages maintain parallel guidance of the carrying plane while allowing rotational movement, preventing wedging without requiring complex additional components.
4Power
If spiral springs are mounted on hinge pins, then lifting moment is transferred efficiently, but the hinge pins experience increased stress
Solution Approach 1:
The invention relocates the spring mounting from the hinge pins to the linkages themselves, using the broader linkage structure to bear the spring forces. This dimensional redistribution of force paths reduces the stress concentration on individual hinge pins while maintaining efficient lifting moment transfer through the linkage system.
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 configuration ensures stable and even upward and downward movement of the carrying plane, maintaining ergonomic positioning of loads, and prevents wedging, enhancing the device's structural integrity and mobility.
Implementation Method 1
a spiral spring for each is mounted with windings running around the hinge pin, so that each spiral spring transfers a lifting moment between the carrying element and the wheel plane and the carrying plane, respectively
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The invention relates to an automatic lifting device with a frame part (2), comprising a wheel plane (3) at the lower side (4) of which a number of carrying wheels (5) are provided, and a carrying plane (6) guided in parallel herewith above the wheel plane (3) as well as a parallel guide (8) and springs effective between the wheel plane (3) and the carrying plane (6), whereby the carrying plane (6) is springily moveable towards the wheel plane (3) in dependence of a load positioned on the carrying plane (6). The parallel guide (8) comprises two or more spring-mounted linkages (10) arranged between the wheel plane (3) and the carrying plane (6).