Dolly Platform Immobilization via Toggle Link Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dollies struggle to securely immobilize heavy loads without relying on brakes, and existing brake mechanisms are not adaptable for heavy-duty applications or incorporation below the platform, limiting their ability to carry and store substantial weights.
Innovation Solution
A dolly design featuring a generally rectangular platform with bearers suspended below, linked by toggle links and pedals, allowing for mechanical advantage to engage with the floor, lift the platform, and secure it in place with locking mechanisms, enabling easy movement and secure immobilization with minimal operator effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If brake mechanisms are used to prevent movement of the dolly, then the dolly can be immobilized, but the mechanism complexity increases and the device cannot be adapted for heavy-duty applications or incorporation below the platform
Solution Approach 1:
The brake mechanism is extracted and replaced by a separate bearer suspension system using toggle links. The bearers are suspended below the platform and can be independently lowered to engage the ground, removing the need for complex wheel-based brakes and enabling incorporation below the platform structure.
Solution Approach 2:
Toggle links are introduced as intermediary elements between the bearers and the platform. These toggle links provide mechanical advantage and enable the bearers to be lowered with minimal operator effort while reliably engaging the ground to immobilize the dolly.
2Quantity of substance
If heavy loads are carried on the dolly, then the load capacity increases, but the operator effort required to lower and raise the bearers increases
Solution Approach 1:
Toggle links serve as mechanical intermediaries that provide significant mechanical advantage. When the bearers are lowered, the toggle links transition from an extended configuration to a more compact one, multiplying the operator's input force and enabling heavy loads to be managed with minimal effort.
Solution Approach 2:
The toggle link mechanism is dynamic, changing its mechanical advantage ratio during operation. As the bearers are lowered and the toggle links approach their fully engaged position, the mechanical advantage increases, making it easier to complete the final stages of engagement even under heavy load.
3Quantity of substance
If the dolly is designed to carry heavy loads, then the load capacity increases, but the dolly weight increases
Solution Approach 1:
The dolly is segmented into distinct functional components: the platform, the bearers, the toggle links, and the wheel assembly. This segmentation allows each component to be optimized independently, using lightweight materials and designs where appropriate, while maintaining overall load capacity.
Solution Approach 2:
The toggle link mechanism provides dynamic mechanical advantage that reduces the effective weight impact. When lowering or raising bearers, the system adapts its mechanical advantage ratio, making operations easier despite the presence of heavy load-carrying components.
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 solution allows for the secure immobilization of heavy loads (up to 500 kg) with minimal pressure, facilitating easy handling and storage while maintaining a lightweight design comparable to conventional dollies, ensuring efficient operation and reduced risk of damage.
Implementation Method 1
each of the bearers being suspended by pairs of toggle links arranged to move into substantially in-line positions during final depressing of the pedal to lift the platform and raise the wheels clear of the floor or ground, and the each pedal has a lever arm affording a mechanical advantage that is amplified by the mechanical advantage of the toggle links themselves moving into in-line positions
Implementation Method 2
each pedal has a spring return to a raised neutral position
Data Source
Figure 1~2
Figure 3~4
Figure 5~13B
AI summary
A load-carrying dolly having four wheels (6, 7) adjacent the corners of its platform (1) is rendered immobile by conversion to a pallet-like condition by lowering bearers (9, 10, 11) into contact with the floor or ground (24) and then raising the platform (1) slightly to raise the wheels (6, 7) clear of the floor or ground by means of either of two pedals (25, 32), one below each end of the platform (1), with linkage (of either of two forms, not shown) to bars (23) connecting in "slave" pairs of toggle links (20, 21) by means of which the bearers are suspended through beams (33) connecting upward extensions (12, 13, 14) at the ends of the bearers (9, 10, 11), the toggle links in each pair becoming locked by mating abutments (28) coming together when the links have passed slightly beyond in-line position, the mechanical advantage of the depressed pedal (25 or 32) being amplified by that of the pairs of toggle links when passing through in-line positions.