Spring-Loaded Sister Hook Locking for One-Handed Load 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, especially when the force applied to the hook goes to zero or fluctuates.
Innovation Solution
A spring-loaded sister hook tool that can be engaged with a load using a one-handed 'stabbing' motion, featuring pivotable arms with a locking mechanism and angled surfaces to secure objects, preventing accidental release and snagging, and allowing easy manual engagement or disengagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional sister hooks are used, then the device can engage loads, but it requires two-handed operation and is unreliable when load varies or goes to zero
Solution Approach 1:
The spring-loaded mechanism enables the tool to automatically open and close jaws without manual intervention during engagement. The spring force self-adjusts to maintain jaw closure under varying loads, eliminating the need for continuous manual pressure while ensuring reliable engagement even when load fluctuates or temporarily reaches zero.
Solution Approach 2:
The locking mechanism transitions from static (traditional sister hooks requiring constant manual pressure) to dynamic (automatically adapting to load conditions). The spring-loaded system dynamically adjusts jaw pressure based on real-time load conditions, maintaining reliable engagement while enabling one-handed operation through automatic adaptation rather than manual adjustment.
2Reliability
If traditional sister hooks are used, then the device can hold loads, but it is prone to accidental release and snagging
Solution Approach 1:
The locking mechanism proactively prevents accidental release by automatically engaging a positive lock when the jaws close around the load. This preliminary anti-action counteracts potential harmful effects of load variation or vibration that might otherwise cause release, securing engagement before problems can occur rather than reacting to them afterward.
Solution Approach 2:
The streamlined housing design with curved surfaces eliminates sharp edges and protrusions that cause snagging on surrounding objects. The smooth contours allow the tool to pass through environments without catching on extraneous items, reducing harmful interactions while maintaining secure load engagement through the internal locking mechanism.
3Productivity
If traditional sister hooks are used, then the device can engage objects, but it requires holding hooks in place until force is applied
Solution Approach 1:
The spring-loaded mechanism performs the work of holding and positioning the jaws automatically. When the user triggers engagement, the spring force immediately closes and secures the jaws without requiring the user to manually maintain pressure or positioning, dramatically speeding up engagement while reducing the skill level needed to operate the device effectively.
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 one-handed operation, secure engagement of loads with fluctuating forces, and reduces snagging, ensuring the tool remains locked without accidental release.
Implementation Method 1
During stabbing, 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 and to hold in 'sister fashion' the object.
Data Source
Figure 1~2
Figure 3~4A
Figure 5~8
AI summary
Sister hook type tool assemblies (20, 21) comprise mating arms (26, 28) having C shape lower ends grip portions that terminate in jaws (42). The arms preferably are held between two spaced apart housings (22, 24). The arms, and housings when present, are held together by a fastener (70, 72) 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 (54) at one end which define a U shape opening (65). An object received in the opening is retained when the jaw ends arms overlappingly close the fork opening, due to action of spring (40). The V shape lower end contour (70) of the mated arms and inclined surfaces (56) 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 (36, 76) are used to keep the jaws from unintentionally opening.