Coaxial Screw Locking Mechanism for Threshold Linear Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mechanical devices for blocking relative movement between structures, such as seismic stops, face challenges in implementing effective blocking mechanisms without significant wear, torque issues, and limited applicability due to hydraulic or pneumatic dependencies and complex mechanical designs.
Innovation Solution
A purely mechanical device using a double coaxial screw-nut couple with a reversible and irreversible screw-nut pair, where an elastic means maintains clearance and causes blocking beyond a stress threshold, allowing for operation in traction, compression, or tension, and varying efforts from a few kilos to several hundred tons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ratchet mechanism is used to block rotation and translation, then the locking effect becomes effective, but there is impact and wear on the teeth and the locking only occurs after significant travel
Solution Approach 1:
The patent replaces the traditional ratchet mechanism with a friction-based locking system. The conical friction surface replaces the toothed ratchet mechanism, eliminating impact and wear on teeth while maintaining reliable locking. The friction cone engages with the rod through friction rather than mechanical interlocking, allowing gradual engagement without shock loads.
Solution Approach 2:
The patent changes the geometric parameters of the locking mechanism by introducing a conical friction surface with a specific angle. The cone angle and friction coefficient are optimized to provide reliable locking while minimizing wear. The gradual engagement of the conical surface allows the locking effect to become effective over a shorter travel distance compared to traditional ratchet mechanisms.
2Reliability
If hydraulic damping devices are used to prevent relative movement, then the blocking capability is achieved, but the device generates considerable bulk and has difficulty in implementation
Solution Approach 1:
The patent replaces complex hydraulic damping devices with a purely mechanical friction-based system. The hydraulic jack is substituted by a conical friction surface that prevents relative movement through friction rather than hydraulic pressure. This mechanical substitution eliminates the need for hydraulic fluid, seals, and control systems, significantly reducing bulk and simplifying implementation.
Solution Approach 2:
The patent extracts the essential function of preventing relative movement from the complex hydraulic system and implements it through a simple friction-based mechanism. By taking out the core blocking capability and removing the hydraulic components, the device achieves the same protective function with much reduced complexity and smaller size.
3Adaptability or versatility
If a single screw is used to lock in both directions, then the device can lock under various forces, but the torque on the screw becomes difficult to reconcile with significant forces
Solution Approach 1:
The patent segments the locking function into two separate conical friction surfaces, one for each direction of force. Instead of requiring a single screw to handle bidirectional locking, the system uses two independent friction cones that can engage separately. This segmentation allows each friction surface to be optimized for its specific direction, reducing the torque requirements on individual components.
Solution Approach 2:
The patent replaces the traditional screw mechanism with a friction-based conical surface system. The screw thread is substituted by a conical friction surface that generates locking force through friction rather than mechanical threading. This substitution significantly reduces the torque required to achieve the same locking effect, as friction forces are distributed over a larger contact area rather than being concentrated at screw threads.
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 device effectively blocks relative movement between structures while minimizing wear and torque, enabling simple implementation and wide-ranging applicability, including seismic and aeronautical applications, with adjustable stress thresholds and reversible operation.
Implementation Method 1
one elastic means, capable of acting on one of the constituent elements of the aforementioned screw-nut pairs, such that: to maintain the screw-nut clearance of said second couple when the stress is less than a threshold fixed by construction
Implementation Method 2
a second screw-nut pair consisting of a so-called irreversible screw and a nut cooperating with said irreversible screw, the cooperation between these two elements having a determined clearance
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
This mechanical device for blocking linear movement between two structures (1, 2) comprises: • a first element (4) fixed to one of the structures, and a second element (5) fixed to or supported against the other structure, the first and second elements cooperating linearly with each other by means of a double coaxial screw-nut pair: ▪ a first screw-nut pair consisting of a reversible screw (9) and a nut (8) cooperating without constraint with the reversible screw; ▪ a second screw-nut pair consisting of an irreversible screw (6) and a nut (7) cooperating with the irreversible screw, the cooperation between these two elements having a determined clearance; one of the elements of the first pair being fixed to one of the elements of the second pair;• an elastic means (10), capable of acting on one of the constituent elements of the aforementioned screw-nut pairs, in such a way as: ▪ to maintain the screw-nut clearance of the second pair when the stress is less than a threshold fixed by construction; and ▪ to cause the cooperation of the elements of the second screw-nut pair to be blocked beyond said stress threshold.