Linear Drive Clutch Locking for Sustained Disengagement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromotive linear drives for furniture, such as hospital beds, require a clutch that remains disengaged even after the operator releases the handle, as current designs often re-engage the clutch due to spring action, limiting independent or faster lowering movements.
Innovation Solution
A blocking element with a leg spring and sliding element or a locking lever designed as a spring steel is used to lock the handle in the disengaged position of the clutch, preventing automatic re-engagement and allowing prolonged disengagement, with optional designs featuring a pivotable release lever and shaped spring for ease of use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a spring-loaded clutch is used to enable rapid lowering movement, then the lowering speed is improved, but the clutch automatically re-engages when the handle is released, limiting independent control
Solution Approach 1:
A blocking element is introduced as an intermediary mechanism between the handle and the clutch engagement. This blocking element prevents the automatic re-engagement of the clutch by physically blocking the engagement path, thereby maintaining independent control while preserving the rapid lowering capability enabled by the spring-loaded clutch.
Solution Approach 2:
The clutch control system is segmented into separate functional components: the handle for actuation, the blocking element for preventing re-engagement, and the clutch mechanism itself. This segmentation allows independent control of each function, enabling the clutch to remain disengaged even after handle release while maintaining the capability for rapid lowering when needed.
2Reliability
If the clutch is designed to automatically re-engage via spring action, then normal operation reliability is improved, but prolonged disengagement for safety applications becomes difficult
Solution Approach 1:
The clutch system transitions from a static spring-loaded engagement design to a dynamic system where the blocking element can be actively positioned to either allow or prevent engagement. This dynamic control enables the system to adapt between normal operation mode (automatic re-engagement) and safety mode (prolonged disengagement) based on operational requirements.
Solution Approach 2:
The engagement state of the clutch is controlled by changing the positional parameter of the blocking element. When the blocking element is in the blocking position, prolonged disengagement is achieved; when moved to the non-blocking position, normal automatic re-engagement occurs. This parameter change approach maintains reliability while enabling adaptability for different operational scenarios.
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 ensures the clutch remains disengaged permanently, allowing for independent control of the drive train, enhancing safety and usability by preventing unintended movements, especially in clinical settings or child safety applications.
Implementation Method 1
at least one coupling part is loaded by means of a spring
Implementation Method 2
the blocking element having a leg spring and a sliding element or the blocking element being formed from a locking lever designed as a spring
Data Source
Figure 1~3
Figure 4
Figure 5~7
AI summary
The drive has a drive train mounted in two part housing (14a, 14b). The drive train is equipped with a linearly movable output unit and with a switchable coupling. The coupling is actuatable by using a release lever (16) arranged outside of the housing. The release lever is locked in a disengaged position of the coupling by using a blocking unit. The blocking unit is designed in the form of a locking lever, such that the locking lever is automatically transferred into the blocking position.