Hand Winch Self-Activating Friction Brake
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hand winches pose security risks due to the lack of a reliable mechanism to maintain the friction brake in an active state when the crank handle is not engaged, leading to uncontrolled unwinding and potential injury to the operator.
Innovation Solution
A self-activating internal friction brake system that automatically engages when a load is applied, utilizing a gear member that moves along the operation shaft to create braking forces without the need for a screw connection, and includes a guiding device for combined rotational and translational movement, ensuring the brake remains engaged even if the crank handle is accidentally removed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a crank handle is screwed onto the operation shaft to activate the friction brake, then the brake can be engaged to control load descent, but the brake becomes inactive and unsafe when the handle is removed or loosened
Solution Approach 1:
The friction brake automatically activates itself when a load is applied to the cable, without requiring manual engagement of a crank handle. The load force itself triggers the brake mechanism through the threaded connection between the gear member and operation shaft, making the system self-regulating and eliminating the need for operator intervention to engage the brake.
Solution Approach 2:
The gear member is pre-positioned with a threaded connection on the operation shaft such that when the winch is installed, the brake mechanism is already in place and ready to activate. The threading geometry is designed in advance to convert any rotational movement of the operation shaft under load into automatic engagement of the friction brake, ensuring safety is prepared before operation begins.
2Reliability
If the crank handle is only slightly unfastened beyond the thread, then the friction contact between gear member and stationary member cannot be built up, but the load can still drive the wind roll and injure the operator
Solution Approach 1:
The system uses the load force itself to trigger the brake activation. When a load is applied to the cable and causes the wind roll to rotate, the threaded connection on the operation shaft automatically pushes the gear member against the stationary member, creating friction contact. This self-activating mechanism ensures that any load, no matter how small, will engage the brake, eliminating the possibility of partial disengagement scenarios.
Solution Approach 2:
The brake system provides automatic feedback through the threaded connection geometry. When the load drives the wind roll and operation shaft, the rotation automatically feeds back to the gear member position, pushing it into friction contact with the stationary member. This continuous feedback loop ensures the brake is always engaged when load is present, preventing unsafe operating conditions.
3Adaptability or versatility
If a removable handle is used for operation, then the winch is more versatile and easier to store, but the friction brake cannot be reliably activated without a screwed connection
Solution Approach 1:
The winch system is divided into separate functional components: the operation shaft with threaded connection for brake activation is permanently integrated into the housing, while the crank handle remains a removable operating tool. This segmentation allows the handle to be removed for storage or versatility while the brake activation mechanism remains permanently in place and functional, independent of handle presence.
Solution Approach 2:
The operation shaft serves multiple functions: it acts as both the rotational drive shaft for the wind roll and as the activation mechanism for the friction brake through its threaded connection. This multi-functionality allows the same component to enable both handle-based operation and automatic brake activation, making the system versatile while maintaining safety functionality even when the handle is removed.
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 enhances safety by preventing uncontrolled rapid unwinding and allows for secure handling by automatically activating the friction brake when a load is applied, ensuring the winch does not operate without control, while also enabling rapid winding up without a load.
Implementation Method 1
a gear member being engaged with the wind roll and having a thrust position in which the gear member acts on a stationary member for generating braking forces directed oppositely to the sense of winding off the elongated member
Implementation Method 2
the gear member is biased by a thrust spring such that, in case of winding up the elongated member, the gear member remains ever in the thread engagement with the operation shaft
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Hand winch comprising a wind roll (25) for receiving a flexible elongated member (31), an operation shaft (33) engaged with the wind roll for transmitting forces there between, a friction brake including a gear member (39) being in engagement with the wind roll and having a thrust position in which the gear member acts on a stationary member (47) for generating braking forces directed oppositely to a sense of winding off the elongated member, characterized in that said gear member is movably mounted on the operation shaft such that, in case of winding off the elongated member, the gear member is displaced form a released position to said thrust position.