COMBINED PULLEY-COUNTERWEIGHT SYSTEM FOR UPLIFT AND INCLINATION MECHANISM OF A CHAIR’S SEAT

This paper addresses the challenges experienced by people with motor disabilities and movement disorders like Parkinson's Disease while independently standing from a seated position on a chair. The paper presents a solution to allow for the inclination of a chair's seat, therefore facilitating the user's sit-to-stand and stand-to-sit motion. The design put forward involves the use of a combined pulley mechanism to lift the seat and consequently support the user, apart from employing a counterweight to restore equilibrium. The paper explores the construction, optimum materials and dimensions of each mechanical component through the use of foundational principles of mathematics and physics. It also outlines the operation of the mechanism as a whole, aided by visuals including three-dimensional computer aided design renders and free body diagrams. Having taken into consideration the disability-poverty nexus, the mechanism proposed deviates from the use of electronic components, making it relatively inexpensive, easy to construct and thus accessible. The paper concludes by highlighting scope for future improvement of the system.