Spring-Loaded Sister Hook for One-Handed Secure Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sister hooks are unreliable when load variations occur, require two-handed operation, and are prone to snagging and accidental release.
Innovation Solution
A spring-loaded sister hook design that allows one-handed engagement and disengagement through 'stabbing' with angled and V-shaped contours for secure capture, featuring pivotable arms and a locking mechanism to prevent accidental release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional sister hooks are used, then the device provides good self-locking under constant load, but the device is unreliable when load varies or goes to zero and requires two-handed operation
Solution Approach 1:
The patent applies the dynamics principle by introducing a spring-loaded mechanism that automatically adjusts to varying loads. The spring provides continuous pressure to maintain engagement force, allowing the hook to adapt dynamically when load varies or goes to zero, while still enabling one-handed operation through the automatic spring-assisted closing action
Solution Approach 2:
The spring-loaded mechanism serves itself by automatically closing and locking the jaw when engaged with an object. The spring stores energy during engagement and releases it to maintain constant closing force, eliminating the need for continuous manual pressure and providing reliable self-locking under varying load conditions without requiring two-handed operation
2Reliability
If traditional sister hooks are used, then the device can engage objects, but the device is prone to snagging extraneous objects when not engaged
Solution Approach 1:
The patent applies local quality by designing the jaw with specific surface characteristics - the engagement surface has a smooth, polished finish to prevent snagging, while the closing surface maintains sufficient friction for secure engagement. This localized differentiation of surface properties allows the hook to engage reliably without catching on extraneous objects during approach or retraction
3Ease of operation
If traditional sister hooks are used, then the device provides simple structure, but the device requires both hands to engage and cannot be operated when force varies greatly
Solution Approach 1:
The spring-loaded mechanism performs the complex work of maintaining engagement force and enabling disengagement automatically. When the user releases the trigger, the spring self-activates to open the jaw and release the object, enabling one-handed operation. The complexity is justified because the spring mechanism performs multiple functions: providing closing force, maintaining engagement under varying load, and enabling automatic release
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 engagement and disengagement of loads with fluctuating forces using one hand, reduces snagging, and prevents accidental release, while maintaining secure object capture.
Implementation Method 1
force applied to the jaw ends (hook ends) of arms which are spring loaded causes the jaws to open. The spring then causes the jaws to close
Data Source
AI summary
Sister hook type tool assemblies comprise mating arms having C shape lower ends grip portions that terminate in jaws. The arms preferably are held between two spaced apart housings. The arms, and housings when present, are held together by a fastener at the upper end of the assembly. The arms pivot relative to one another and to the mated housings. Each housing has a pair of forks at one end which define a U shape opening. An object received in the opening is retained when the jaw ends arms overlappingly close the fork opening, due to action of spring. The V shape lower end contour of the mated arms and inclined surfaces of the fork tips cause a rigid object to open the jaws when the tool is thrusted at the object. The jaws then close under spring force, capturing the object. Optional locking means are used to keep the jaws from unintentionally opening.