Bowden Cable Tensioning with Dual-Stop Damping for Window Lifters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing window lifter technologies with cable-guiding elements fail to maintain effective damping over long periods and under varying thermal conditions, leading to noise and material degradation due to the instability of elastic components when compressed for extended times.
Innovation Solution
A device with a cable-guiding element featuring a spring and two pairs of stops, where the first pair engages an elastic damper to manage cable tension and prevent overloading, and a second pair acts as hard stops to prevent further compression, ensuring consistent damping performance by releasing kinetic energy before the second pair engages, optionally using a harder damping element for enhanced effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single elastic damping element is used in cable-guiding elements, then initial damping effect is achieved, but damping performance deteriorates over time and under thermal stress
Solution Approach 1:
The damping function is segmented into two distinct pairs of stops: the first pair with an elastic damping element for initial energy absorption, and the second pair as hard stops for final limitation. This segmentation allows each component to specialize in its optimal function, with the elastic element handling transient impacts and the hard stops providing long-term structural limitation, thereby maintaining reliable damping performance throughout the service duration.
Solution Approach 2:
The first pair of stops with the elastic damping element provides beforehand cushioning by absorbing kinetic energy during normal operation before the cable-guiding element reaches the second pair of hard stops. This prior cushioning prevents direct impacts on the hard stops, reducing material degradation and maintaining consistent damping performance over time and under thermal stress.
2Force
If elastic components are compressed for extended times, then cable tension is maintained, but material degradation and noise occur under varying thermal conditions
Solution Approach 1:
The elastic damping element performs preliminary action by absorbing cable tension fluctuations and kinetic energy during normal operation, preventing the cable-guiding element from repeatedly impacting the hard stops. This preliminary energy absorption reduces material degradation and noise generation, allowing the system to maintain cable tension without the harmful effects of extended compression and repeated impacts.
Solution Approach 2:
The potential harm of repeated impacts and material degradation is converted into benefit by using the elastic damping element to absorb and dissipate kinetic energy through controlled deformation. The elastic material's temporary compression and recovery converts harmful impact energy into beneficial damping action, reducing noise and preventing material fatigue while maintaining cable tension.
3Device complexity
If only one pair of stops is used, then device complexity is reduced, but overloading of elastic material cannot be prevented
Solution Approach 1:
The stopping function is segmented into two pairs: the first pair with elastic damping for normal operation and the second pair as hard stops for overload protection. This segmentation enables the system to handle both routine cable tension variations and extreme overload conditions, preventing elastic material overloading while maintaining acceptable device complexity through a straightforward two-pair configuration.
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 provides a durable and effective damping mechanism that maintains performance over time and under thermal stress, reducing noise and preventing material overloading, ensuring a consistently good damping effect.
Implementation Method 1
a spring arranged between a support surface of the receptacle and a head of the cable-guiding element configured to keep the cable under tension
Implementation Method 2
an intermediate elastic damper, so that the damper is only partially compressed... a large part of the kinetic energy of the cable-guiding element is released during its compression
Implementation Method 3
an intermediate elastic damper... the damper is only partially compressed... a large part of the kinetic energy of the cable-guiding element is released during its compression
Data Source
AI summary
A device for compensating cable play within a cable window-lifter, including a cable including at least one section with a Bowden, the device including a cable-guiding element configured to receive an end of the Bowden, mounted in an axially displaceable manner in a receptacle, the device including a spring arranged between a supporting surface of the receptacle and a head of the cable-guiding element, configured to keep the cable under tension and thereby compensating cable play, where stop surfaces are provided on the cable-guiding element and on the receptacle, which can engage with each other during the loading of the cable and thereby stop further compensation of the spring, and where an elastic material damping the stop noises is arranged between the stops.