Transport Trolley Caster Locking for Automatic Mode Switching
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Solution Overview
Problem
Existing transport trolleys with steerable and fixed casters require complex manual adjustments to switch between driving modes, which can lead to user errors and inconsistent chassis characteristics.
Innovation Solution
A transport trolley with a displacement mechanism and locking device that allows the fixed caster to be moved between passive and active positions, coupled with a locking mechanism to ensure smooth transitions between driving modes, utilizing forces from a towing vehicle to actuate the mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If manual adjustments are used to switch between driving modes, then the transport trolley can change operating modes, but complex manual adjustments are required which lead to user errors and inconsistent chassis characteristics
Solution Approach 1:
The system uses the towing vehicle's acceleration forces to automatically actuate the displacement mechanism, which in turn automatically locks the swivel casters and positions the fixed caster. This self-service mechanism eliminates the need for manual adjustments and ensures consistent, reliable chassis characteristics without user intervention.
Solution Approach 2:
The coupling between the drawbar forces and the displacement mechanism creates a feedback system where the acceleration forces from towing automatically trigger the mode switching sequence. The system senses the operational context through the forces applied and automatically adjusts the caster configuration accordingly, ensuring reliable and consistent chassis characteristics.
2Adaptability or versatility
If manual adjustments are used to switch between driving modes, then the transport trolley can change operating modes, but user errors occur during the adjustment process
Solution Approach 1:
The system automatically detects the need to switch modes through the acceleration forces applied during towing and self-adjusts the caster configuration. The displacement mechanism and locking device are automatically actuated by the towing forces, eliminating all manual intervention and user errors associated with manual adjustment.
Solution Approach 2:
The manual mechanical adjustment system is replaced with an automated force-actuated system. The drawbar forces that would normally require manual interpretation are directly coupled to the displacement mechanism, automatically triggering the mode switch without human intervention and eliminating user errors.
3Ease of operation
If the fixed caster is lowered to the ground to provide lateral guidance, then the transport trolley operates in normal mode with four steerable casters, but the fixed caster cannot be used for guidance
Solution Approach 1:
The system dynamically reconfigures the caster arrangement based on operational needs. When towing forces are applied, the displacement mechanism automatically raises the fixed caster from the ground to engage it as a guidance element, while simultaneously locking the swivel casters. This dynamic reconfiguration allows the system to switch between steering-flexibility mode and guidance-mode seamlessly.
Data Source
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AI summary
The invention relates to a transport cart comprising a cart base, a caster assembly with at least four casters arranged in the respective corner-adjacent areas of the cart base and capable of rolling the cart base, each of which is steerable about substantially vertical axes, a drawbar assembly coupled to the cart base and capable of being moved from a vertical to a horizontal orientation, a fixed caster assembly with at least one non-steerable fixed caster, a displacement mechanism for displacing the fixed caster between a passive position in which the fixed caster is lifted from a road surface and an active position in which the fixed caster rests on that road surface, and a locking device for locking at least one of the casters in an orientation suitable for straight-ahead travel.According to the invention, the locking device and the displacement mechanism are coupled to each other in such a way that, in the passive position of the fixed castor, the locking device fixes the associated swivel castor in a non-steerable position.