Tensioning Device with Opposing Threads and Self-Locking
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Solution Overview
Problem
Existing tensioning devices, such as load binders, face challenges in securely stabilizing heavy objects without reversing mechanical advantage, leading to potential accidents and injuries, especially for users of modest strength, and lack sufficient friction to maintain tension.
Innovation Solution
A tensioning device with a longitudinal structure and extensible members, featuring a gearbox mechanism with opposing threads and end effectors that provide mechanical advantage, combined with load tighteners to prevent unwanted rotation and maintain tension, allowing for secure stabilization and positioning of heavy objects with proportional force feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a threaded member with a steep helix angle is used to generate mechanical advantage, then large tension forces can be developed, but the mechanism may overhaul in reverse causing the threaded member to pull out and the complementary member to rotate
Solution Approach 1:
The patent converts the harmful reverse overrunning effect into a beneficial self-locking mechanism by designing the threaded member with a shallow helix angle. This prevents the mechanism from overrunning in reverse, automatically maintaining tension without requiring additional friction elements, thus resolving the contradiction between generating large tension forces and maintaining mechanical advantage stability
Solution Approach 2:
The patent changes the critical parameter of the threaded member's helix angle from steep to shallow. This parameter change fundamentally alters the mechanism's behavior, enabling it to maintain mechanical advantage and prevent reverse overrunning while still generating sufficient tension forces, thereby resolving the reliability issue
2Force
If multiple threads are used to provide mechanical advantage, then large forces can be generated, but the mechanism is particularly susceptible to reverse overrunning and unwanted rotation
Solution Approach 1:
The patent converts the potential instability of multiple-threaded mechanisms into a stable, self-locking system by using a shallow helix angle design. This prevents the unwanted rotation and reverse overrunning that plagues conventional multi-thread mechanisms, while maintaining the ability to generate large compression forces, thus resolving the contradiction between force generation and structural stability
3Force
If a gear mechanism is used to provide mechanical advantage, then large forces can be generated, but the mechanism lacks sufficient friction to maintain tension and prevent reverse motion
Solution Approach 1:
The patent eliminates the need for additional friction elements by designing the threaded member with a shallow helix angle that creates inherent self-locking. This converts the potential sliding issue into a stable, maintenance-free tension-holding mechanism that reliably prevents reverse motion without requiring high-friction components, resolving the contradiction between force generation and tension maintenance
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 safe and efficient stabilization of heavy objects with reduced risk of accidents by providing proportional force feedback and maintaining tension, allowing users of modest strength to secure loads effectively, even when using hand tools or power tools.
Implementation Method 1
a barrel gear (30) affixed to the exterior of the barrel with the barrel gear encircling the barrel perpendicular to the axis of the barrel's length, and a drive gear engaged with the barrel gear forming a bevel gear
Implementation Method 2
The first end of the barrel includes right-hand threads within the first end of the barrel, while the second end of the barrel includes left-hand threads
Data Source
AI summary
A tensioning device uses two perpendicular gears so that common hand tool such as wrenches or socket wrenches can be used to drive the gears to rotate a barrel having two oppositely threaded apertures. Shafts having complementary threads inserted into the threaded apertures and means for connecting chain, wire rope, cable, or straps will be extended or retracted when tools rotate the driving gear. End effectors on the shafts include hooks or clevises for securing cargo, pads for use as a jack, and ball ends for use as an adjustable mechanical linkage such as the top link of a three-point agricultural hitch. Load locks can secure the threaded shafts from unwanted rotation while in transit or in other service.