Adjustable Arm Support with Cam Actuator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wheelchair arm supports have limited adjustable positions and require removal of pins or bolts for adjustments, which can be cumbersome and inefficient for accommodating different users' sizes and comfort preferences.
Innovation Solution
The design incorporates a first and second member pivotally attached via an actuator, allowing for adjustable arm supports with a wide range of motion through the use of pivot joints and actuators, enabling easy adjustment without the need to remove fasteners, thereby accommodating various user sizes and preferences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional arm supports use pins or bolts for adjustment, then the structure is simple and reliable, but the adjustment process becomes cumbersome and time-consuming
Solution Approach 1:
The patent replaces the traditional pin or bolt removal mechanism with a cam-based mechanical system. The cam surface, when actuated by the set screw, automatically pivots the bearing plates to the desired position and locks them in place, eliminating the need for manual pin or bolt removal and significantly reducing adjustment time.
Solution Approach 2:
The cam mechanism is designed to be self-actuating through the set screw. When the set screw is loosened, the tension spring automatically pivots the bearing plates to the correct position using the cam surfaces, and then locks them in place without requiring additional manual intervention for positioning.
2Adaptability or versatility
If arm supports have multiple adjustment positions, then adaptability to different users is improved, but device complexity increases
Solution Approach 1:
The patent employs a dynamic cam surface design that allows the bearing plates to pivot through multiple positions. The cam surface is shaped to guide the plates through predetermined angular positions, providing multiple adjustment options while maintaining a relatively simple overall mechanism structure.
Solution Approach 2:
The adjustment mechanism is segmented into discrete cam surfaces (first cam surface, second cam surface, etc.) that correspond to different adjustment positions. Each cam surface segment controls a specific position, allowing for multiple adjustment options while keeping the mechanism manageable and not overly complex.
3Productivity
If arm supports use tension springs and cam surfaces for automatic positioning, then adjustment speed is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent uses a set screw with adjustable tension to control the force applied to the cam mechanism. By adjusting the set screw tension, the positioning precision can be fine-tuned without changing the cam surface geometry, allowing for adaptive precision control that reduces stringent manufacturing requirements.
Solution Approach 2:
The tension spring provides continuous mechanical feedback to the cam mechanism, ensuring that the bearing plates are reliably positioned and locked at each cam surface engagement point. This feedback mechanism compensates for minor manufacturing variations in the cam surfaces, maintaining positioning accuracy without requiring extremely precise manufacturing.
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
An arm support for a personal mobility vehicle can include a first member having a first end that defines a first cavity, and a first attachment member that extends through the first cavity so as to define an axis. The arm support can further include a second member having a first end that is disposed within the first cavity such that the second member is pivotally attached to the first member by the first attachment member. The arm support can further include an actuator that extends through the first end of the second member and through the first cavity. The actuator can be operatively coupled to the second member such that actuation of the actuator causes the second member to pivot about the axis.