Development of an attachable handbike:

by S.T.W. Ten-Jet-Foei

Institution: Delft University of Technology
Year: 2009
Keywords: construction; design; mobility
Record ID: 1251462
Full text PDF: http://resolver.tudelft.nl/uuid:ba932298-8cf8-4427-aa0e-0089571c9cb8


Mobility makes people independent and is a necessity of life. This is also for people with a spinal chord lesion. They are fully depending on their wheelchair and this is not an efficient transport product for distances further then 2 km. A handbike is the solution and give the users more freedom to become mobile in the city and at the same time maintain a proper health. For my graduation project I have developed an attachable handbike which can be used on fixed frame and foldable wheelchairs. The advantage is that the user can maintain his personal wheelchair and convert this to a tricycle with arm propulsion. The project is done at Van Raam BV in Varsseveld in cooperation with Welzorg sport. Van Raam makes people mobile with specialized and unique bicycles like tandems, wheelchair bikes, three wheel bikes and comfort bikes. Welzorg supply products for people with a function or mobility disability, such as walkers, wheelchairs, handbikes and mobility scooters. Welzorg has the knowledge about handbikes and contact with end users and Van Raam has the knowledge to manufacture the handbike. My graduation assignment is to design an attachable handbike which is technically, functional and aesthetically outstanding. It will need a universal mounting system that suit several types of wheelchairs and the size of the handbike need to be adjustable to several user dimensions. After analyzing the context of the handbike the design guidelines are listed and the starting points for the design phase are generated. In the conceptualization phase principle solutions are generated for the mounting system that can be divided in a docking station on the wheelchair and a coupling mechanism on the handbike. Several quick mock ups are made to test the working principle of some ideas. Several sketches are made for the design of the frame which will have a slim, solid and sportive look. From these ideas three concepts for the coupling mechanism and the appearance where chosen to elaborate further on. One of the concepts is chosen and detailed in the realization phase. The mounting mechanism had to fit on several wheelchairs tubes, be light and have enough strength. The result is a docking station that is easy to add on and of on the wheelchair from the side while the user maintain his position in the wheelchair. The coupling mechanism is working like an excavator which hooks and lock the docking station and lift the front wheels of the wheelchair from the ground. With a lever the coupling block is compressed with the docking station. The system is easy to release with a squeeze lever at the top of the handbike and the lever at the coupling mechanism. From a 3D CAD model a 1:1 scale prototype of the handbike is build so it can be tested for functionality, appearance and usability. The users where enthusiastic about the design and would fit their lifestyle. The driving performance was comfortable but they where used to a smaller turning radius. The coupling mechanism worked but the users needed some practice to get used to the…