Powerless Helical Locking Mechanism for Screw-Driven Doors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Helix-driven door machines face issues with complex and unreliable locking mechanisms that require additional power sources for unlocking, which complicates their operation and reliability, especially during manual operation.
Innovation Solution
A powerless helical locking mechanism featuring a screw with variable lead angle and a self-adaptive nut, where the screw slot is divided into sections with different lead angles for locking and unlocking, allowing bidirectional rotation to achieve self-locking and self-unlocking without external power, utilizing sliding or rolling friction for efficient manual operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional locks with brakes, clutches, or electromagnetic/hydraulic/pneumatic driving modes are used, then locking and unlocking functions are achieved, but the mechanism becomes complicated and reliability decreases
Solution Approach 1:
The screw slot is divided into three distinct sections: working section with lead angle greater than friction angle, locking section with lead angle less than friction angle, and transition section between them. This segmentation allows different functional zones within a single continuous structure, achieving both simplicity and reliability.
Solution Approach 2:
The screw features a variable lead angle that changes along its length, transitioning from a larger angle in the working section to a smaller angle in the locking section. This dynamic geometric variation enables the mechanism to switch between different operational states (working vs. locking) based on position, eliminating the need for separate locks or actuators.
2Ease of operation
If additional power sources are used for unlocking, then unlocking function is achieved, but the system requires external power and becomes more complex
Solution Approach 1:
The mechanism utilizes the door's own motion and the variable lead angle geometry to achieve automatic unlocking. When the door opens and the self-adaptive nut moves along the screw, it automatically transitions from the locking section back to the working section, causing spontaneous unlocking without requiring external power, motors, or additional actuators.
Solution Approach 2:
The invention removes all external power sources, electromagnetic components, hydraulic systems, and pneumatic devices from the locking/unlocking mechanism. By extracting these complex subsystems and replacing them with a purely mechanical variable lead angle screw, the system achieves power-independent operation while maintaining full locking and unlocking functionality.
3Reliability
If the lead angle is less than the friction angle for self-locking, then locking reliability is improved, but manual operation becomes difficult due to high friction
Solution Approach 1:
The screw slot is divided into three distinct sections: working section with lead angle greater than friction angle, locking section with lead angle less than friction angle, and transition section between them. This segmentation allows different functional zones within a single continuous structure, achieving both simplicity and reliability.
Solution Approach 2:
The screw features a variable lead angle that changes along its length, transitioning from a larger angle in the working section to a smaller angle in the locking section. This dynamic geometric variation enables the mechanism to switch between different operational states (working vs. locking) based on position, eliminating the need for separate locks or actuators.
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 mechanism provides a simple, reliable, and power-independent locking and unlocking system for helix-driven door machines, ensuring secure locking and easy manual operation by leveraging the difference in lead angles to manage friction effectively, enhancing the reliability and usability of door mechanisms.
Implementation Method 1
locking section with the lead angle less than the friction angle... the lead angle of screw pair is less than the friction angle as cause self-locking
Implementation Method 2
the self-adaptive nut is assembled with the screw with variable lead angle into a screw kinematic pair... the pin shaft and screw slot with any lead angles form the matched screw pair to realize the power and motion transfer
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention disclosed a passive screw-driven door machine locking mechanism, which may realize the locking and passive self-unlocking of various screw-driven door machines. The present invention includes at least two parts of variable lift angle screw and self-adaptive nut. The screw slot of variable lift angle screw is divided into three sections: working section with the lift angle more than the friction angle, locking section with the lift angle less than the friction angle, and transition section between them; variable lift angle screw is connected with the power source, which may let the variable lift angle screw rotate clockwise and counterclockwise; the self-adaptive nut is composed by connected shaft sleeve and pin shaft etc, the self-adaptive nut is assembled with the variable lift angle screw, the pin shaft and screw slot with any lift angles may form the matched screw pair to realize the power and motion transfer. The self-adaptive nut is linked with the door, when the power source drive the variable lift angle screw to rotate CW and CCW, the self-adaptive nut and door may synchronously move in parallel with that of variable lift angle screw, through self-adaptive nut setting in and setting out the locking section of the variable lift angle screw, realize the locking and unlocking of door machine.