Elevator Safety Catch Device With Cam Guide Mechanism
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Solution Overview
Problem
Existing elevator safety devices require significant space due to the need for a long adjustment path and incline for the braking mechanism, and can cause damage to the rail, especially when using transport rollers.
Innovation Solution
A slide stop device with a guide roller unit that allows the braking element to be pressed against the rail over its entire length, distributing pressure evenly and using a degressive guide surface to adjust the braking element's position, which reduces the space requirement and minimizes rail damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a sliding mechanism with an inclined plane is used to move the brake wedge, then sufficient braking force can be generated, but a large amount of space is required for the adjustment path
Solution Approach 1:
The patent replaces the traditional sliding mechanism with an inclined plane with a cam mechanism. The cam profile is designed to directly generate the required braking force through its geometric shape, eliminating the need for a long inclined plane while achieving the same braking effect. This substitution of mechanical systems resolves the contradiction by maintaining force generation capability while significantly reducing the adjustment path length.
Solution Approach 2:
The patent changes the geometric parameters of the cam profile to optimize the force generation. By carefully designing the cam radius, eccentricity, and profile curvature, the system achieves sufficient braking force within a compact space. The parameter optimization allows the cam to convert rotational motion into the required linear braking force without requiring a long adjustment path.
2Ease of operation
If transport rollers are used to move the safety wedge, then the wedge can be transported into braking position, but severe damage to the rail occurs
Solution Approach 1:
The patent removes the transport rollers from the system entirely. Instead of using rollers to transport the safety wedge, the design relies on the cam mechanism to directly position and apply the brake wedge. This extraction of the harmful component (rollers) eliminates the source of rail damage while maintaining the ability to transport and apply the braking element.
Solution Approach 2:
The patent introduces a cam profile as an intermediary mechanism between the actuation system and the brake wedge. The cam serves as a mediator that converts actuation motion into precise wedge positioning and application without requiring direct contact between transport elements and the rail, thereby preventing rail damage.
3Volume of moving object
If a narrow gap in the carriage is used, then the structure is compact, but a long guide surface is required which increases space requirement
Solution Approach 1:
The patent replaces the traditional carriage with narrow gap and long guide surface with a cam-based actuation mechanism. The cam profile inherently provides the guiding function while allowing for a more compact overall structure. This substitution eliminates the need for the long guide surface within the carriage, achieving both compactness and adequate guidance.
4Length of stationary object
If the chock is positioned close to the guide rail in the initial state, then space is saved, but insufficient distance prevents proper braking activation
Solution Approach 1:
The patent optimizes the initial positioning parameters of the brake wedge relative to the cam profile. The cam is designed with an appropriate base circle radius and eccentricity that ensure the wedge is positioned at an optimal initial distance from the rail. This parameter optimization allows the wedge to be close enough to save space while maintaining sufficient distance for reliable braking activation when the cam is actuated.
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 enables a space-optimized design for elevator systems, allowing for effective braking with reduced installation space and minimizing the risk of rail damage, while maintaining sufficient contact pressure without causing plastic deformation.
Implementation Method 1
the guide roller unit rolls on the guide surface
Implementation Method 2
the guide surface being designed such that the adjustment of the braking element in the braking direction is degressively translated into the adjustment of the braking element in the pressing direction
Implementation Method 3
the friction between the braking surface and the rail enables further adjustment of the braking element in the braking direction
Data Source
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AI summary
A safety catch device (1) for a lift system (2) comprises a movable brake element (5) that can be adjusted in a pressing direction (11) towards a counter surface (9), for a braking procedure. In the assembled state, a disc (3) is arranged between the braking element (5) and the counter surface (9). In addition, a guide arrangement (44) is provided for the braking element (5), which comprises a guide surface (45) and an individual guide roller unit (43). The guide roller unit (43) interacts with the guide surface (45) in such a way that in the event of an adjustment of the brake element (5) occurring in a braking action direction (22), an adjustment of the braking element (5) likewise occurs in the pressing direction (11). The pressing direction (11) is respectively perpendicular to the braking action direction (22). The guide roller unit (43) rolls on the guide surface (45) during the braking procedure and the guide surface (45) is designed such that a transformation of the adjustment of the braking element (5) occurring in the braking action direction (22) decreasingly results in the adjustment of the braking element (5) occurring in pressing direction (11). The invention also relates to a lift system (2) comprising a safety catch device (1) of this type and a method for braking a lift car (4) that can be carried out with a safety catch device (1) of this type.