The client has cerebral palsy with very little movement other than of his head and drives his electric chair with his chin. He has a pet dog and wanted to have some degree of control when they go out together, though he is accompanied by his carer.
A self-retracting dog lead is situated behind the seat, the cord goes to the side of the chair passing between a capstan (powered by a windscreen wiper motor) and spring loaded pinch rollers lifted by a solenoid to allow free run. Using his forehead to operate a two-way switch, the client releases the cord to allow the dog to move away. Releasing the switch provides an effective brake. If the dog comes to “heel”, the cord rewinds itself, but if the dog needs a little “encouragement”, the capstan is used to winch it in.
The client is now able to control his dog himself.