As the Festive Season approaches I thought you might like to apply your inventive skills to help a friend of mine. To be more precise I ought to admit that you would be helping me figure out how to help that friend.
The problem: The friend's sister is thinking about acquiring a 'hand bike' add on to her wheel chair. I am not sure which one, but I will point you towards the Spanish company Batec as my Kath has one and the connection between the chair and the tractor unit is very efficient and low effort. It is probably the best connector in the UK.
This is the Batec Mini 2, a powered hand bike:
- Batec Mini 2.png (483.29 KiB) Viewed 44139 times
All of these hand bike style machines tend to have two brake levers and both of them operate on the front wheel making front wheel skids very easy. Thus the plan is to use one brake lever to drive brakes on the wheelchair. The simplest way of achieving that is to fit wheelchair wheels with brake hubs of which the best known is probably the Sturmey Archer.
My own experiments in this area show that the brake lever operating the back brakes must be able to pull a lot of cable to actuate two hubs at the same time. The other problem is to get a simple connection between the tractor unit and the wheelchair that the user can operate easily and quickly. We used to use screwed wire cable connectors which were neither easy, quick or possible for Kath to set up from the wheelchair.
One suggestion is to use hydraulic bike brakes but one would presumably need a double size piston in the lever unit. The other issue is how to handle to connection/disconnection of the chair and tractor unit. My scan of bike hydraulics kit makes me feel that there is not too much stuff out there for the DIY person to modify for special projects. Of course there is a whole lot of automotive kit to be had, but I am not sure how one might use it...
Your thoughts would be welcome.
Seasons Greeting to you all.
Pete
