Arm Support Shell Restraint Against Sliding Toward the Hand
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Solution Overview
Problem
Existing arm support devices struggle with insufficient grip on the arm, particularly when the arm is raised, due to the need for precise joint orientation and potential displacement of the arm shell beyond the elbow, leading to discomfort and reduced freedom of movement.
Innovation Solution
Incorporation of a restraining element that limits displacement of the arm shell towards the hand while allowing flexibility, designed to be inelastic and extend axially, preventing excessive movement without restricting the opposite direction, and optionally integrated into clothing for ease of use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the arm support device uses a passive actuator to apply support force to the arm, then the arm support function is improved, but the arm shell may displace along the arm towards the hand especially when the arm is raised
Solution Approach 1:
The restraining element is pre-configured to counteract the displacement tendency of the arm shell before it occurs. When the passive actuator applies support force, the restraining element is already in position to prevent the arm shell from sliding towards the hand, eliminating the need for corrective actions after displacement begins.
Solution Approach 2:
The restraining element acts as an intermediary component between the arm shell and the arm. It mediates the interaction by allowing necessary movement while blocking excessive displacement, thus resolving the conflict between providing support force and maintaining proper arm shell positioning.
2Device complexity
If the arm shell is simply placed in the arm support device, then the device structure is simplified, but the grip of the arm shell on the arm becomes insufficient especially when the arm is raised
Solution Approach 1:
The device is segmented into functional components: the arm shell for placement, the passive actuator for support, and the restraining element for positioning control. This segmentation allows each component to perform its specific function while maintaining overall structural simplicity.
Solution Approach 2:
The restraining element introduces localized control quality to specific regions where displacement occurs. Rather than making the entire device complex, only the necessary locations are reinforced with restraining elements to provide adequate grip and positioning.
3Power
If the force transmission element is designed as a rod or compression force transmission element with eccentric arrangement, then the torque support function is improved, but the arm shell displacement towards the hand is exacerbated when the arm is raised
Solution Approach 1:
The restraining element is pre-positioned to counteract the displacement effect caused by the eccentric force transmission before the arm is raised. This preliminary anti-action prevents the arm shell from displacing towards the hand even though the torque support mechanism creates a tendency for such displacement.
Solution Approach 2:
The design accepts the displacement tendency as a natural consequence of the torque support mechanism, then uses the restraining element to convert this potential harm into a controlled feature. The restraining element transforms the uncontrolled displacement into a defined range of motion.
Data Source
AI summary
A device for supporting at least one arm of a user, wherein: the device has at least one arm-supporting element comprising an arm shell for placing on the arm, at least one passive actuator which is configured to apply a force to the at least one arm-supporting element, and at least one counter bearing for the force to be applied, with at least one force transmission element and a counter bearing element; the arm-supporting element is connected to the force transmission element via an articulation so as to be pivotable about at least one pivot axis; the device additionally has at least one restraining element which limits a movement of the arm shell along the arm towards the hand when the device is worn, but does not affect a movement of the arm shell in the opposite direction; and the at least one restraining element is designed to be flexible but inelastic, and/or has at least one portion which extends in an axillary manner.