Cable Actuator with Dual Cam Mechanism for Mobility Aid Control
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Solution Overview
Problem
Existing mobility aids, such as wheelchairs and standing frames, often require complex manual or electromechanical latching mechanisms that are difficult to operate efficiently, especially when multiple actuation mechanisms need to be controlled simultaneously.
Innovation Solution
A cable actuator system that allows selective operation of multiple cable-actuated devices using a single manual controller, enabling actuating forces to be applied to one, two, or all cables, and withdrawing forces from them, facilitating smooth transitions between different positions like sitting, standing, and reclining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple separate manual controllers are used to control multiple latching mechanisms, then each mechanism can be independently controlled, but the overall system complexity increases and ease of operation decreases
Solution Approach 1:
The patent combines multiple separate manual controllers into a single integrated controller that can selectively actuate multiple cable-actuated devices. The controller housing contains multiple cam mechanisms that can independently engage with different cables, allowing one-handed operation of multiple latching mechanisms simultaneously or sequentially, thereby improving ease of operation while maintaining functional independence of each actuated device.
Solution Approach 2:
The single manual controller is designed with multi-functionality to control multiple different cable-actuated devices. The controller can selectively engage with first, second, or both cables through independent cam mechanisms, allowing one controller to perform the functions of multiple separate controllers, thus reducing overall system complexity while maintaining operational versatility.
2Ease of operation
If a single manual controller controls multiple cable-actuated devices, then ease of operation improves, but the mechanism complexity within the controller increases
Solution Approach 1:
The controller is segmented into multiple independent cam mechanisms, each responsible for actuating a specific cable. The first cam mechanism is configured to engage the first cable while the second cam mechanism engages the second cable. This segmentation allows each cam to be independently adjusted and operated, managing the internal complexity through modular organization while providing simplified external operation through a single controller housing.
Solution Approach 2:
The cam mechanisms serve as intermediary elements between the user's manual input and the multiple cable-actuated devices. Each cam converts rotational or linear motion into the appropriate cable tension or release, mediating the control signal from the single controller to multiple different actuators. This intermediary mechanism manages the complexity by providing standardized interfaces between the controller and various cables.
3Reliability
If complex electromechanical latching mechanisms are used, then reliability of locking may improve, but ease of operation and system simplicity deteriorate
Solution Approach 1:
The cable-actuated devices utilize spring-loaded latching mechanisms that automatically engage and disengage based on cable tension. When the cable is tensioned by the cam mechanism, the latch automatically locks into position; when tension is released, the spring automatically returns the latch to the unlocked position. This self-service mechanism eliminates the need for complex electromechanical solenoids or motors, maintaining high reliability through simple mechanical self-actuation while greatly improving ease of operation.
Data Source
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Figure 3A~3B
AI summary
A cable actuator includes a housing and a cam disposed in the housing. The cam includes a first cable retaining portion and a second cable retaining portion. The cam is movable between a first position in which the first cable retaining portion is in an actuated position and the second cable retaining portion is in a return position, and a second position in which the first cable retaining portion is in a return position and the second cable retaining portion is in an actuated position.