Cable Winch Emergency Brake Using Threaded Drum-Driven Actuation
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Solution Overview
Problem
Existing cable winches lack an effective emergency braking mechanism that can decelerate a falling load, such as a person hanging from a rope, to a standstill without additional energy input and prevent jerky braking.
Innovation Solution
An emergency braking device for a cable winch with a cable drum rotatable about a pivot axis, featuring a braking unit, a driver, and an adjuster with a thread and connecting structure, which engages with a mating thread to exert a translational force on the brake unit, decelerating the cable drum using the rotational energy of the drum and the falling load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an emergency braking mechanism is added to decelerate a falling load, then the safety and control of the braking process is improved, but the device complexity increases
Solution Approach 1:
The patent combines the driver mechanism and braking unit into an integrated emergency braking device. The driver (110) with projections engages directly with the cable drum's driver contour, and the braking unit (108) is positioned to contact the drum, merging the actuation and braking functions into a single compact assembly that reduces overall device complexity while maintaining safety.
Solution Approach 2:
The emergency braking device is designed to activate automatically without external energy input. The spring unit (124) stores potential energy that is automatically converted to kinetic energy when the driver engages the cable drum, causing the braking unit to contact the drum and initiate deceleration. This self-service mechanism eliminates the need for external power sources or control systems, reducing device complexity while ensuring reliable safety function.
2Speed
If a braking force is applied to stop the cable drum, then the deceleration capability is improved, but the risk of jerky braking and rope force spikes increases
Solution Approach 1:
The spring unit (124) positioned between the driver and braking unit acts as a cushioning element. When the driver engages the cable drum, the spring compresses gradually, allowing the braking unit to contact the drum in a controlled manner. This beforehand cushioning prevents sudden impact forces, reducing jerky braking and rope force spikes while maintaining effective deceleration capability.
Solution Approach 2:
The emergency braking device uses dynamic engagement through the spring unit that allows gradual compression and force distribution. The spring's elastic properties enable the system to adapt to the falling load's energy, distributing the braking force over time rather than applying it instantaneously. This dynamic approach smooths the deceleration process, preventing harmful force spikes on the rope while achieving the required stopping capability.
3Use of energy by moving object
If the driver engages the cable drum to transmit rotational movement, then the energy conversion for braking is improved, but the structural complexity increases
Solution Approach 1:
The patent extracts only the essential energy conversion function needed for emergency braking. The driver (110) with simple projections engages directly with the cable drum's driver contour, transmitting rotational movement to compress the spring unit and activate the braking unit. This extracted approach uses only the necessary mechanical engagement elements without additional complex transmission mechanisms, improving energy conversion efficiency while minimizing structural complexity.
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 device effectively decelerates the cable drum to a standstill, reducing the maximum force on the rope and mitigating sudden increases, ensuring a safe and controlled braking process without additional energy input.
Implementation Method 1
The thread engages with a mating thread in order to cause a linear movement of the feeder towards the brake unit through the rotary motion transferred from the driver to the feeder
Implementation Method 2
The spring unit can be secured in an inactive state of the emergency braking device. The spring unit can be unlocked in the active state of the emergency braking device to allow the drive element to be pressed into the drive element contour along the axis of rotation
Implementation Method 3
a braking unit (108) configured to decelerate the cable drum (104) when a translational force acts on the braking unit (108)
Data Source
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AI summary
An emergency braking device (102) for a cable winch (102) with a rotatable cable drum (104) is presented, wherein the emergency braking device comprises a braking unit (108) configured to decelerate the cable drum (104) when a translational force acts on the braking unit (108), further comprising a driver (110) rotatable about the axis of rotation (106) and linearly movable along the axis of rotation (106) and configured to engage in a driver contour of the cable drum (104) in an active state of the emergency braking device (102) in order to transmit a rotational movement of the cable drum (104) to the driver (110), and an adjuster (112) with a thread (114) and a connecting structure (116), wherein the adjuster (112) and the driver (110) are connected via the connecting structure (116) in a rotationally fixed and linearly movable manner, and wherein the thread (114) engages in a counter thread (118),to cause a linear movement of the feeder (112) in the direction of the brake unit (108) by means of the rotary movement transmitted to the feeder (112), in order to exert the translational force on the brake unit (108).