| 摘要 |
The device comprises a casing (8) supported on a pair of rods (4) mounted in the backrest, and a pair of parallel, horizontal support rods (30'') supported by and moved between support wheels (32-38) mounted in a pressure-absorbing stand or framework (10) inside the casing. The front ends of the support rods support a pressure-sensitive support plate (46) and the rear ends are joined to a metal plate (48). A servomotor (50) is used to move the support rods backwards and forwards. A lock mechanism mounted in the framework can be activated to fix the support rods into position. A control unit (56) receives pressure signals from the support plate and sends control signals to the servomotor. |
