Adjustable Pressure Roller Cam Disc for Variable Torque Door Closers
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Solution Overview
Problem
Existing door closers with cam mechanisms struggle to adapt to different operating modes, such as slide rail and scissor linkage operations, due to fixed torque curves, making it difficult to meet fire protection torque requirements without replacing the entire unit, which is costly.
Innovation Solution
A door closer design with a pressure roller that can adjust its position relative to a symmetrical cam disc, allowing for customizable torque curves by altering the pressure roller's path and cam disc alignment, enabling the same door closer to function in various operating modes and applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed cam disc design is used, then the door closer can be manufactured inexpensively, but it cannot adapt to different operating modes and fire protection torque requirements
Solution Approach 1:
The cam disc is designed with multiple selectable run-off surfaces that allow the torque curve to be dynamically changed by repositioning the pressure roller. This enables the same cam disc to adapt to different operating modes (slide rail, scissor linkage, parallel linkage) and fire protection requirements without requiring multiple different cam disc designs.
Solution Approach 2:
The cam disc is segmented into multiple distinct run-off surfaces, each optimized for a specific operating mode. The pressure roller can be repositioned to engage different segments of the cam disc, allowing selective activation of appropriate torque curves for different applications while maintaining a single unified component.
2Adaptability or versatility
If the pressure roller position is fixed, then the manufacturing cost is reduced, but the torque curve cannot be adjusted for different applications
Solution Approach 1:
The pressure roller is designed with adjustable positioning capability along the cam disc circumference, allowing the torque curve to be customized for different applications. This adjustable feature is implemented through simple mechanical means (such as repositionable mounting holes or adjustable linkages) that do not significantly complicate the manufacturing process.
3Adaptability or versatility
If the closer spring preload is adjusted, then the torque at specific angles can be changed, but the overall torque curve shape remains unchanged and fire protection requirements cannot be met
Solution Approach 1:
Instead of merely adjusting spring preload, the invention dynamically changes the torque curve shape by repositioning the pressure roller on the cam disc. This allows the entire torque profile to be optimized for fire protection requirements, not just the magnitude at specific angles, while using the existing spring mechanism without additional complexity.
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
This design allows for adaptable torque curves, enabling the same door closer to be used in different operating modes, reducing manufacturing costs and enabling the door closer to meet fire protection torque requirements without needing replacement.
Implementation Method 1
a pressure roller (101), which rolls pressed on a lifting cam (103) of the door closer (100)
Implementation Method 2
The pressure roller (101) is pressed by a closer spring (102) against the lifting cam (103)
Data Source
Figure 1A~1C
Figure 1D~1E
Figure 1F
AI summary
The closer (100) has a pinion shaft (104) on which a cam disk (103) is arranged in a rotationally fixed manner and a pressure roller (101). A closing spring (102) forces the pressure roller against a roll-off surface of the cam disk by an operative connection (106, 111, 107). The roller is arranged relative to an axial centre of the pinion shaft in such a way the pressure roller, when a door leaf of a conventional door coupled to the pinion shaft is opened or closed, is moved along a trajectory. The trajectory runs past the axial centre of the pinion shaft and the run-off surface of the disk.