Friction Grip Hoist Dynamometer Pin Overload Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Friction grip hoists face challenges with overload detection systems that require specific fastening to equipment, are sensitive, and lack accuracy and adjustability, leading to unreliable and fatiguing measurements.
Innovation Solution
Incorporating a 'dynamometer' pin with embedded measurement means and a monitor unit that processes radial forces and issues alerts or controls the pulley's rotation, allowing for reliable, compact, and independent overload detection without specific fastening, and reducing pin stress through diametrically opposite positioning of driving and holding components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring force sensor is arranged in the zone where the hoist is fastened to the equipment, then overload detection is achieved, but the measurement means require predetermined fastening and are sensitive to installation variations
Solution Approach 1:
The measurement means are extracted from the fastening zone and relocated to the pin about which the pulley wheel rotates. This extraction eliminates the requirement for predetermined fastening arrangements while maintaining overload detection capability, as the pin's deformation directly reflects the radial forces without being influenced by fastening variations
Solution Approach 2:
The pin acts as an intermediary element between the load and the measurement means. By placing strain gauges on the pin, the system measures forces through this intermediate component that naturally transmits radial loads, thereby avoiding direct measurement in the fastening zone which is sensitive to installation variations
2Reliability
If a spring force sensor is used for overload detection, then the hoist can detect overload conditions, but the measurement means lack accuracy and are difficult to adjust
Solution Approach 1:
The mechanical spring force sensor is replaced with strain gauges mounted on the pin. This substitution transitions from a mechanical measurement system to an electro-mechanical system, providing higher measurement precision, easier calibration, and improved accuracy in detecting radial forces on the pin
Solution Approach 2:
The measurement approach changes from measuring force directly with a spring sensor to measuring strain deformation on the pin using strain gauges. This parameter change from direct force measurement to strain measurement enables more precise and adjustable overload detection through electrical signal processing
3Device complexity
If measurement means are placed outside the pin, then the hoist structure remains simple, but the measurement means are sensitive and lack reproducibility
Solution Approach 1:
The measurement means are merged with the pin structure by mounting strain gauges directly on the pin surface. This integration ensures that the measurement system moves with the pin and directly measures its deformation, eliminating sensitivity issues while maintaining structural simplicity. The measurement means become an inherent part of the pin assembly rather than a separate external component
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
Enables reliable, reproducible, and less fatiguing overload detection, independent of fastening method, with reduced stress on the pin and improved accuracy and durability of measurement means.
Implementation Method 1
the pin, known as a 'dynamometer' pin, about which the wheel of the pulley is mounted to rotate is fitted with measurement means for measuring at least one magnitude representative of the at least radial forces or loads exerted on said pin, and in that the hoist includes a monitor unit suitable for communicating with said measurement means, said monitor unit being fitted with processor means for processing said at least one magnitude measured by said measurement means
Data Source
AI summary
A friction grip hoist (1) includes: at least one body (2); a pulley (3) mounted on the body, the pulley including a pin (4) and a wheel (5) having an outer peripheral groove (6) for receiving a cable; drive elements (7) for driving rotation of the wheel; and holder elements (15) for holding the cable inside the groove (6) of the wheel. The pin, referred to as a “dynamometer” pin, about which the wheel of the pulley is mounted to rotate is fitted with measurement elements (11) for measuring at least one magnitude representative of at least radial forces or loads exerted on the pin, and the hoist includes a monitor unit fitted with processor elements and with elements for issuing an alert signal and/or for controlling the elements (7) for driving rotation of the wheel of the pulley as a function of the at least one measured magnitude.