| 摘要 |
An invalid chair 2 comprises a power source, a motor, a gearbox and control circuitry encapsulated in a propulsion unit 24, which may be urged into engagement with the ground by a spring, or preferably two springs, acting between the chassis and the unit's spindle 26. Alternatively, springs may act between the chassis 4 and pivoting arms connected to the spindle ends 28,20. Each spring may be enclosed in a telescoping damping cylinder 36,38. An external battery may be provided to extend the range of operation and to act as a weight increasing the downwards force on the unit 24, which may be encapsulated as a sheet metal or plastic moulded hollow roller. The chair 2 may be propelled by handles 10,12 or by the occupant via rear wheels 18,20 or by the propulsion unit 24, via a speed control located on a hand grip. Folding of the chair 2 may be facilitated by detachment of the unit 24. |
