Retraction Device with Bistable Coupling to Reduce Impact Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional retraction devices often produce knocking noises and have limited service life due to component damage during operation.
Innovation Solution
A bistable coupling mechanism is introduced, allowing the spring energy store to be fixed to either the housing or the driver element, with a blocking body that switches the coupling between stable states, preventing clutch release and ensuring noise-free operation by connecting the spring energy store to the driver element in a form-fitting manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the spring energy storage device is continuously connected to the drive element during retraction, then the retraction force is maintained, but impact noises occur and component damage limits service life
Solution Approach 1:
The coupling state between the spring energy storage device and drive element is made dynamic rather than static. The coupling is engaged only during the acceleration phase when needed, and disengaged during the deceleration phase to prevent impact noises and component damage, while maintaining reliability through timed engagement.
Solution Approach 2:
The coupling mechanism operates periodically, engaging the spring energy storage device to the drive element at specific phases of the retraction stroke (during acceleration) and disengaging at other phases (during deceleration). This periodic engagement/disengagement pattern eliminates continuous connection while maintaining necessary functionality.
2Device complexity
If the spring energy storage device is fixed to the housing, then the structure is simple, but the drive element cannot be properly coupled during operation
Solution Approach 1:
A coupling mechanism acts as an intermediary between the spring energy storage device (fixed to housing) and the drive element. This mediator enables temporary connection during specific operational phases while maintaining the simple fixed structure of the spring to housing, resolving the conflict between structural simplicity and operational functionality.
3Productivity
If the coupling is engaged early in the retraction stroke, then the spring energy is transferred efficiently, but the blocking body cannot switch states properly
Solution Approach 1:
The coupling switching mechanism utilizes a different dimension or degree of freedom than the linear retraction motion. The blocking body switches states based on positional triggers along the stroke, allowing proper sequencing of engagement/disengagement while maintaining efficient energy transfer timing through spatially distributed switching points.
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 low-noise retraction device with a longer service life by decoupling the spring energy store from the housing during operation, reducing noise and extending the device's operational lifespan.
Implementation Method 1
a spring energy storage device (110), wherein a first end (112) of the spring energy storage device (110) is connected to the housing (20) and wherein the spring energy storage device (110) is charged to a maximum operating value when the drive element (60) is in the parking position (62) and is discharged to a residual energy value when the drive element (60) is in the end position (61)
Implementation Method 2
The coupling has a locking element that is slidable between the housing and the drive element
Implementation Method 3
This unit is designed, for example, as a damper. The damper can be actuated before the engagement of the spring energy storage device. Thus, when the clutch engages, the speed of the engagement element is already reduced.
Data Source
Figure 1~2
Figure 3~5
Figure 6~10
AI summary
The invention relates to a retraction device (10) comprising a housing (20) and a driving element (60), which is guided in the housing between a parked position (62) and an end position (61), wherein a first end (112) of a spring energy accumulator (111) is connected to the housing, and the spring energy accumulator is loaded to a maximum operating value when the driving element is in the parked position and is unloaded to a residual energy value when the driving element is in the end position. A second end (113) of the spring energy accumulator can either be fixed to the housing or can be coupled to the driving element by means of a bistable coupling (150). The coupling has a blocking element (140) which can be moved between the housing and the driving element. By virtue of the invention, a low-noise retraction device with a long service life is developed.