Elevator Safety Device Wedge Spring Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current elevator safety devices have a relatively large size, particularly in the direction of movement along the guide member, which affects their efficiency and cost-effectiveness.
Innovation Solution
The elevator safety device incorporates a spring assembly with a fixed end attached to a housing and a free end that is movable, allowing a roller to wedge between the guide rail and the spring assembly, reducing the device's size and weight while providing effective braking through elastic force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the spring assembly has both ends fixed to the housing, then the structural stability is improved, but the device length increases
Solution Approach 1:
The patent extracts the fixation function from one end of the spring assembly, leaving it as a free end rather than fixing it to the housing. This allows the spring assembly to be shorter while still providing sufficient structural stability through the fixed end and the wedge-shaped geometry that creates frictional engagement with the guide rail.
Solution Approach 2:
The spring assembly is given a wedge shape with varying width along its length, creating a dimensional variation that provides mechanical advantage. The wider fixed end provides stability while the narrower free end reduces the overall length requirement, effectively solving the contradiction through geometric transformation.
2Force
If the spring assembly is made longer to provide sufficient elastic force, then the braking capability is improved, but the device size increases
Solution Approach 1:
The spring assembly has non-uniform cross-sectional dimensions, being wider at the fixed end and narrower at the free end. This local variation in geometry concentrates the elastic force generation at the fixed end while reducing the overall length, allowing sufficient braking force without increasing device size.
Solution Approach 2:
The spring assembly utilizes the composite effect of elastic deformation and frictional engagement. The elastic force from the spring works in combination with the friction force generated at the contact surface with the guide rail, creating a compound braking mechanism that is more efficient than either mechanism alone, thereby reducing the required spring length.
3Reliability
If the roller is positioned far from the guide rail, then the activation reliability is improved, but the response time increases
Solution Approach 1:
The roller is pre-positioned in close proximity to the guide rail in the normal state, ready for immediate engagement. This preliminary positioning eliminates activation delay while maintaining reliability through the wedge-shaped spring assembly that ensures proper engagement geometry is achieved as soon as the roller contacts the guide rail.
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 solution results in a smaller and lighter safety device that reduces material and production costs while maintaining reliable braking capabilities, suitable for both upward and downward movements.
Implementation Method 1
the roller is moved due to frictional engagement with the guide rail towards the free end of the spring assembly
Implementation Method 2
the roller elastically bends the free end of the spring assembly away from the guide rail
Implementation Method 3
the roller is located within the tapered region defined by the spring assembly and the guide rail
Implementation Method 4
the roller is moved due to frictional engagement with the guide rail towards the free end of the spring assembly
Data Source
AI summary
An elevator safety device comprises a housing attachable to an elevator car or to an elevator counterweight of an elevator system, the housing comprising a passage for allowing a guide member to pass through. A brake shoe is attached to the housing and is located on a first side of the guide member passing through the passage. A spring assembly is arranged on a second of side of the guide member and comprises at least one leaf spring, the spring assembly having a fixed end, which is fixed to the housing, and an opposite free end, which is not fixed to the housing. The spring assembly extends at an angle with respect to the guide member, defining a tapered region between the guide member and the spring assembly, wherein the free end of the spring assembly is arranged closer to the guide member than the fixed end of the spring assembly. A roller is, at least in an activated condition of the elevator safety device, located within the tapered region defined by the spring assembly and the guide member. The roller is capable of moving along the spring assembly towards the free end of the spring assembly into a wedged condition between the spring assembly and the guide member.